#just the fluid surrounding its nucleus

[kagoutiss]

was thinking the other day about how parasites are ganondorf’s solution for so many things. now cant unsee him being a massive nerd about parasites

[welcome-to-cell-hell]

WORLDBUILDING NOTES: CELL DIVISION

I’m taking genetics this spring and it got me thinking about how cells divide, here are my thoughts! This is def one of the more sci-fi posts I’ve written and not gonna be 100% scientifically accurate so bear with me lol.

Let’s start with the notion that the nucleus is essentially a cell’s brain. It sits inside their head, coding proteins and all that, along with brain functions like thoughts, emotions, personalities, learning, etc, which are directly linked to noncoding DNA. These functions are not as understood by cells (and not understood at all by humans) as the coding DNA is, but tiny changes in the coiling of these segments and weak interactions with surrounding noncoding DNA form the cell’s psyche. Even after a cell divides, that cell’s chromatin will fold right back to its original shape and retain that individual cell’s memories and character, drawn back into place by those I.M.F.s (Intermolecular forces). And the same thing happens in prokaryotes since it’s not reliant on the nucleus itself. But I’m not a biochemist and I’m not gonna pretend to know what I’m talking about, so that’s all the detail you’re getting. All you need to know is noncoding DNA arranged a certain way = unique cell with their own thoughts and feelings.

When a cell divides, the process is a little different from what we understand IRL. Usually, interphase takes most of the time and happens before everything else. The cell grows, replicates its DNA, and duplicates its organelles. Instead, the only things that happen before cytokinesis are fragments of organelles pinching off and replication of DNA. Basically, in real life you get G1 ➡️ S ➡️ G2 ➡️ M, and here you get S ➡️ M ➡️ G (excluding checkpoints). During the replication process, a cell will start to feel light-headed, and take this as a sign that it’s probably time to step back from work. Little by little, noncoding I.M.Fs will get broken by ribosomes, and instinct will take over to carry out what we observe IRL.

By time chromosomes start condensing, the cell has forgotten how to speak, think, or even who they were before. But they’re okay, and just going through the motions laid out by instinct. A trusted non-dividing cell usually accompanies them to make sure everything goes well and to prepare the interphase tube for them (explained in a bit). Cells often describe M phase as fading into a dreamless sleep or deep meditation while you’re still up and moving around, and then waking up when it’s over.

In this state, the cell undergoes all stages of M phase, with half of the chromosomes staying in their head where they’ll decondense, and the other half, along with the organelle fragments, move to the end of the tail to become a vesicle that pinches off from the especially supple membrane found there. While this happens, they sit quietly as the spindles separate the chromosomes, and then gently detach the vesicle.

When the cell “wakes up,” they have a monster headache and they’re holding a vesicle about the size of a soccer ball. It looks more like a real cell than anything, housing a full set of DNA and fragments that will grow into full organelles. The vesicle then goes straight into the interphase tube, but the nondividing cell can’t take it from them until they’re fully awake because they’ll protect it on instinct and might get aggressive abt it. The tube looks a lot like the ones in canon, it’s kept warm and the blue fluid in there is full of all the nutrients the growing cell will need. Usually, it also has certain chemicals that will randomize many of the I.M.Fs that the decondensed chromatin will form, resulting in a new individual with their own personality, and not just a perfect clone of the “parent” cell. Noncoding interactions that control the expression of things like membrane/flagella/eye color and other physical attributes like height and patterns are also randomized, but coding DNA, expression of cell type features, and basic skills stay the same. In about an hour or two, when I.M.F.s in the daughter cell finalize, they’re brought out of the tube and sent right to the shower. After that, they get dressed, and are then taken to wherever the parent cell works and shown the ropes. Due to those preserved interactions, they usually catch on pretty quickly, and they’ll be living their own life in no time.

That was mitosis. As for meiosis, it’s pretty much the same, except you need more interphase tubes and only professionals can oversee the process. But unfortunately, the original parent cell’s I.M.F.s don’t get preserved because they were built on diploid framework, and volunteering to undergo meiosis is seen as a huge selfless sacrifice. Before it happens, the cell can do whatever they want, which usually involves a big party with friends or a sightseeing trip. Some really out-there ones that have canonically happened include: being in charge of the news station for a day, giving all the WBCs silly string (they ended up keeping it as a distraction method), throwing random things with trebuchets, punching a hated celeb on live TV, and formally outlawing the phrase “gettin’ jiggy with it” just to piss off a co-worker who said it all the time.

[mariacallous]

In satellite pictures, they look like the pale blue and gray eggs of a giant butterfly, laid in tight patterns on some dismal leaf. The eggs, made of steel, are tanks brimming with radioactive fluid—contaminated water from Japan’s Fukushima nuclear plant. The water will soon be diluted and pumped into the sea. Núria Casacuberta Arola, of ETH Zürich, is among those who will be watching. Closely.

“We have access to a ship that goes to the coast of Fukushima every year, sometimes once, sometimes twice,” she says. Casacuberta Arola and her colleagues regularly drop an assembly of jars into waters near the incapacitated power plant to collect samples at different depths. The lids of the jars close automatically, one by one, as the device is slowly pulled back up to the surface.

By doing this, and also taking sediment samples from the seabed, they hope to be able to tell in the coming months and years whether the disposal of water from Fukushima is causing a noticeable rise in radiation in this corner of the Pacific Ocean. The water release could start as early as next month. If there is a significant bump in radiation levels in the surrounding waters, it will mean things have gone very wrong.

In 2011, a massive tsunami struck Fukushima Daiichi Nuclear Power Station. The defensive sea wall intended to protect the plant from such an onslaught was many meters too low to stop the monster wave. Seawater flooded the facility, ultimately leading to partial meltdowns and huge explosions at some of the reactors. It is considered one of the worst nuclear accidents in history.

In the years since, workers have had to constantly pump water into Fukushima’s stricken reactors, which still contain hot nuclear fuel. This water has, thankfully, done its job of keeping the reactors cool, but it has become irradiated in the process, meaning it can’t just be flushed away. Workers have kept the used cooling water on-site, building tank after tank in which to store it. All the while, they have known that they will eventually have to dispose of it. Today, there are 1.3 million metric tons of contaminated water on-site. And no space for any more tanks. The time to do something about it is here.

It has taken years of research, modeling, and sampling, but earlier this month the International Atomic Energy Agency gave its approval for a discharge plan. Japan’s Nuclear Regulation Authority signed off on the proposals at the same time, meaning that the Tokyo Electric Power Co (Tepco), which is in charge of the plant and its cleanup, has full authority to begin slowly releasing the water into the ocean via a 1-km-long underwater pipe.

Some aren’t happy. Local fishers are strongly opposed to the plan, and there have been street protests in South Korea. Yet many scientists are highly confident that the discharge will be perfectly safe.

The contaminated water, enough to fill more than 30,000 fuel-truck semi-trailers, contains a mix of unstable chemical elements, known as radionuclides, that emit radiation. To keep these radioactive components to a minimum, Tepco has installed special water purification technology that treats the water before storage. In essence, it involves passing the contaminated water through a series of chambers containing materials that can adsorb radionuclides. The isotopes stick to those materials and the water flows on, a little cleaner than before.

However, it is not 100 percent effective, and many of the radionuclides it’s designed to extract, such as the isotopes caesium-137 and strontium-90, for example, can still be found in the stored water. There are also some isotopes the system can’t remove at all, such as carbon-14 and tritium, a form of hydrogen with two neutrons and one proton in its nucleus (hydrogen usually contains just one proton).

Despite this, the water is extremely safe because the concentrations of radionuclides are so low, explains Jim Smith, a professor of environmental science at the University of Portsmouth. “I’m not concerned,” he says of the plan to discharge the water.

Many of the above radioactive isotopes were released into the ocean at the time of the disaster in 2011—and some traveled. One study found them floating around 3,000 km away in the Arctic Ocean six years after the accident. Once the discharge begins, radionuclides will undoubtedly spread out into the Pacific, but this is very unlikely to have a noticeable effect on the environment, Smith says.

For context, he points out that he has many years of experience studying the effects of radiation on living things near the destroyed nuclear power plant in Chernobyl. Even there, where exposure to radiation is much greater, the impact appears to be tiny. “We know radiation damages DNA, probably there are subtle effects of radiation at these levels, but we don’t generally see a significant effect on the ecosystem,” he says, referring to that work.

Plus, tritium—one of the isotopes that can’t be removed from the stored water—is already present all around us at low concentrations, though higher levels are associated with nuclear-related activities. The authors of one 2018 study speculated that unusually high levels of tritium in the Rhône river delta in France were down to historical pollution from the watchmaking industry—tritium has been used to make glow-in-the-dark paint for watch dials.

What many people don’t realize is that water containing tritium is actually routinely released into the sea—sometimes in vastly greater quantities than are to be discharged from Fukushima—by nuclear facilities all around the world, including in the US, Europe, and East Asia. The Cap de la Hague nuclear processing site in France releases 11,400 terabecquerels (Tbq) of tritium every year, which is more than 13 times the total radioactivity of the tritium across every storage tank at Fukushima.

Tepco is regularly testing the stored water ahead of the release, the company says. The water will be re-treated, multiple times if necessary, and diluted more than 100 times to bring its tritium radioactivity concentration down to no more than 0.0000000015 TBq per liter, a level equivalent to a 1/40 of Japan’s national safety standards. Roughly 70 percent of the stored water also contains radionuclides other than tritium that are at concentrations exceeding regulatory limits, says the Japanese government—levels of these will also be brought down to below Japan’s regulatory standards. The water will then be tested again before being discharged.

For a final point of comparison, Smith calculates that cosmic rays interacting with the Earth’s atmosphere over the Pacific Ocean annually cause the natural deposition of 2,000 times more tritium than will be introduced by the gradual Fukushima release.

Tatsujiro Suzuki at Nagasaki University remembers watching in horror as the disaster unfolded back in 2011. “We all thought that this kind of thing would never happen in Japan,” he says. At the time, he was working for the government. He recalls the confusion over what was happening to the reactors in the days following the tsunami. Everyone was gripped by fear.

“Once you experience that kind of accident, you don’t want to see another one,” he says. The long shadow cast by the disaster means that, for the water release plan, the stakes—at least in terms of public trust—could not be higher.

Suzuki argues that it’s not quite fair to compare the Fukushima water to fluids discharged from other nuclear facilities elsewhere in the world because of the challenge of cleaning up the many different radionuclides here. “This is an unprecedented event, we have not done this before,” he says, adding that he thinks the procedure is “probably safe” but that there is still room for human error or an accident, such as another tsunami, that could cause an uncontrolled release of the water into the sea.

Tepco and the International Atomic Energy Agency have considered such possibilities and still judge the risk to human and marine life to be extremely low. Sameh Melhem, now at the World Nuclear Association, formerly worked for the Atomic Energy Agency and was involved in some of the research to evaluate the discharge plan. “I think it’s very safe for the operators themselves and also for the public,” he says, adding: “The radionuclide concentrations coming from this release, it’s negligible.”

Last November, Casacuberta Arola and her colleagues collected samples of seawater off the coast of Fukushima, and they have recently begun to analyze them. The scientists measure the levels of various radionuclides that might be present. For tritium, that means removing all helium from the sample and waiting to see how much new helium emerges from the water as a product of radioactivity. This makes it possible to extrapolate the amount of tritium that must be present, explains Casacuberta Arola. She and her team have records of radionuclide measurements like this from the sea off Fukushima going back years.

“We already know that the values that we see now close to Fukushima are close to the background values,” she says. If that changes, they should find out fairly quickly. As will the International Atomic Energy Agency and other observers, who, separately, intend to sample water and wildlife in the area in the coming years to keep an eye on things.

Smith says that despite overwhelming evidence that the water release will be entirely safe and heavily scrutinized at every turn, it is not surprising that some people are skeptical of the plan. They have a right to be, he adds, given the troubled history of the plant.

At the same time, the threat posed by the release—even in a worst-case scenario where everything goes wrong—is miniscule compared to some of the other environmental risks in the region, such as the effects of the climate crisis on the Pacific Ocean, Smith says.

Casacuberta Arola agrees. Negative coverage of the discharge plan has been used to “brainwash” people, she argues, and to instill fear against the nuclear energy industry. “To me,” she adds, “it’s been very much exaggerated.”

[jake213j]

Back Pain Relief in East Windsor: Could a Herniated Disc be the Culprit?

Has your back pain been making everyday tasks feel impossible? Is it a struggle to simply get through the day? If you have been negatively impacted by back pain, know that physical therapy can help to provide answers– and solutions.

One possibility is that you have a herniated disc. This can put extra pressure on the muscles and nerves that surround the spinal column. If you are experiencing pain on one side of the body, pain that radiates to the arms or legs, aching, burning sensations in the affected area, and pain with certain movements, talk to your doctor about how physical therapy may benefit you.

Impact Physical Therapy in NJ has the tools and the talented staff to help you make your back pain a thing of the past.

What causes a herniated disc?

Your spinal discs are squat discs of tissue that lie between the vertebrae. A disc consists of a fluid-filled center called the nucleus pulposus encased in an outer structure called the annulus fibrosus. This arrangement makes the disc both tough enough and spongy enough to absorb shocks.

Unfortunately, that toughness has its limits. Sometimes a disc will lose hydration over time, causing the nucleus pulposus to shrink. The disc loses its height, which stresses the spinal joints and may cause the disc to bulge outward. A herniated disc is what occurs when a spinal disc protrudes through the outer ring. This leads to numbness, pain, and discomfort.

A number of factors can cause a herniated disc. Herniated discs can occur suddenly due to an auto accident, workplace accident, or sports injury that traumatizes the spine. Certain motions, like turning, twisting, or lifting heavy objects can also cause a herniated disc.

Overweight and elderly people are at a higher risk for developing a herniated disc. This is because strain is more likely when spinal discs have to support more weight. And as we age, our discs begin to lose some of their protective water content, which causes discs to slip more easily out of place.

Interestingly enough, not all herniated discs will lead to pain (especially because the discs themselves are relatively low in innervation and vascularization). However, when a herniated disc does cause symptoms, these symptoms often include:

Pain that worsens with forward flexion or prolonged sitting—forward flexion may also cause the pain to “peripheralized” or move further away from the spine

Arm or leg pain, numbness, tingling, and weakness (if the herniated disc

compresses on an adjacent nerve root that innervates the affected limb)

Pain that improves or “centralizes” (moves toward the spine) with spinal extension, such as when lying down or lying prone

Neck or back pain, stiffness, and muscle spasms at the level of the injured disc

How does physical therapy help?

Physical therapy is an essential component of the recovery process from a herniated disc. If your symptoms are interfering with your daily activities or at work, or if they last longer than two weeks, we recommend seeing a physical therapist.

Your physical therapist will implement a variety of different techniques for pain relief and healing. Deep tissue massage, electromagnetic stimulation, and heat and cold therapies are just a few of the passive treatments available to you.

Deep tissue massage applies pressure to ease spasms and deep muscular tension caused by a herniated disc. Heat therapy promotes healing by increasing blood flow to the damaged area, while inflammation is targeted and reduced in cold therapy. Electric nerve stimulation works by sending small electric currents along the nerve pathway to limit pain receptors and reduce muscle spasm.

A physical therapist’s active treatments focus on joint movement, stability, flexibility, strength, and posture. To strengthen the back muscles, a physical therapist will teach you core stabilizing exercises. You’ll also strengthen and condition your body by performing a variety of exercise movements. In addition, a physical therapist will teach you proper stretching and flexibility exercises.

Don’t wait, contact Impact Physical Therapy in NJ today!

If your back pain is slowing you down, turn to physical therapy for help. To establish if you have a herniated disc, a physical therapist will perform a thorough examination and analyze your medical history.

A physical therapist will create and administer a treatment plan tailored to you that targets your pain head on. At Impact Physical Therapy, our goal is to help you live a more active and pain-free life. Contact us to help you get back on your feet after a herniated disc.

[mysticstronomy]

WHAT IS A BLACK HOLE TSUNAMI??

Blog#115

Wednesday, August 18th ,2021

Welcome back,

Here on Earth, earthquakes and underwater volcanic eruptions may displace enough ocean water to create a tsunami, a drumbeat of waves reaching huge heights as they approach land.

Now, astrophysicists have used computer simulations to show that in deep in space, tsunami-like structures may form on much bigger scales, from gas escaping the gravitational pull of a supermassive black hole. In fact, the mysterious environment of supermassive black holes may host the largest tsunami-like structures in the universe, researchers say. The NASA-funded study is published in The Astrophysical Journal.

“What governs phenomena here on Earth are the laws of physics that can explain things in outer space and even very far outside the black hole,” said Daniel Proga, astrophysicist at the University of Las Vegas, Nevada.

Black holes are mysterious by themselves. But for theoretical astrophysicists like Proga, a greater puzzle is solving the mathematical equations that describe how black holes distort their environments even dozens of light-years away.

When a black hole with a mass larger than a million Suns feeds off material from a surrounding disk at the center of a galaxy, the system is called an “active galactic nucleus.” Active galactic nuclei may additionally have relativistic jets at their poles and a thick shroud of material blocking our view of the central activity. But circulating plasma above the disk, just far enough that it won’t fall into the black hole, shines incredibly bright in X-rays — so bright that astronomers have been able to catalog over a million of these objects.

Strong winds, at least in part driven by this radiation, storm out of this central region in what’s called an “outflow.” Researchers want to understand the complicated interactions of gas with X-rays, and not just near the event horizon, where those X-rays are produced. The effects of these central X-rays can be important all the way out to tens of light-years from the black hole. In addition to launching outflows, X-ray irradiation may explain the presence of various populations of denser regions called clouds. Last year Proga and colleagues published simulations showing that more distant clouds can be produced within an outflow.

“These clouds are ten times hotter than the surface of the Sun and moving at the speed of the solar wind, so they are rather exotic objects that you would not want an airplane to fly through,” said lead author Tim Waters, a postdoctoral researcher at UNLV who is also a guest scientist at Los Alamos National Laboratory. 

Now, the group has demonstrated for the first time just how complicated the clouds within these outflows from the central black hole engine really are. Their simulations show that just within the distance where the supermassive black hole loses its grip on the surrounding matter, the relatively cool atmosphere of the spinning disk can form waves, similar to the surface of the ocean.  When interacting with hot winds, these waves can steepen into spiraling vortex structures that can reach a height of 10 light-years above the disk.  That’s more than twice the distance from the Sun to its closest star, which is a little over 4 light-years.  By the time tsunami-shaped clouds form, they are no longer influenced by the black hole’s gravity.

The simulations show how X-ray light coming from the plasma near the black hole first inflates pockets of heated gas within the atmosphere of the accretion disk beyond a certain distance from the active galactic nucleus. Heated plasma rises like a balloon, expanding into and disrupting the surrounding cooler gas.  It can be scorching — hundreds of thousands to tens of millions of degrees, no matter which unit of measurement one might use.  

Instead of a subsea volcanic eruption causing tsunamis, these hot pockets of gas in the outskirts of the accretion disk initiate the outward propagating disturbance. As the gas particles form a gigantic tsunami-like structure, it blocks the accretion disk wind, spawning a separate pattern of spiral structures known as a Kármán vortex street, with each vortex spanning a light-year in size. The phenomenon is named for physicist Theodore von Kármán, one of the founders of NASA’s Jet Propulsion Laboratory.

This all may sound exotic and far-flung, but Kármán vortex streets are common weather patterns on Earth that structural engineers must worry about, especially with regards to bridges.

The new results contradict a longstanding theory that the clouds in the vicinity of an active galactic nucleus form spontaneously out of hot gas through the action of a fluid instability. They also go against the idea that magnetic fields are needed to propel cooler gas from a disk into the wind.

“While it all makes sense in hindsight, it was initially quite confusing to observe that thermal instability cannot produce cold gas directly, yet it can take the place of magnetic fields by lifting cold gas into the wind,” said Waters.

Armed with these simulations, researchers hope to work with observational astronomers to use telescopes to look for signs of these dynamics.

No satellite currently in orbit can hands down confirm the new findings. But NASA’s Chandra X-Ray Observatory and the European Space Agency’s XMM-Newton have detected plasma near active galactic nuclei with temperatures and velocities consistent with the simulations.

Stronger evidence may come from future missions. NASA’s forthcoming IXPE mission, launching in November, may contribute to scientists’ understanding of these phenomena. The X-Ray Imaging and Spectroscopy Mission (XRISM), a collaboration between NASA and the Japanese Space Agency (JAXA), could study these phenomena when it launches later this decade. The European Space Agency is also planning a mission called ATHENA, the Advanced Telescope for High-ENergy Astrophysics, which has this capability, too.

Until then, the researchers will continue improving their models and comparing them with available data, caught in the whirlwind of this mystery.

SOURCE: www.nasa.gov

COMING UP!!

(Saturday, August 21st, 2021)

“GHOSTLY RINGS FOUND AROUND A BLACK HOLE??”

[againstcorona-blog]

What Is the Coronavirus?

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What is the coronavirus?

Coronaviruses are a family of hundreds of viruses that can cause fever, respiratory problems, and sometimes gastrointestinal symptoms too. The 2019 novel coronavirus is one of seven members of this family known to infect humans, and the third in the past three decades to jump from animals to humans. Since emerging in China in December, this new coronavirus has caused a global health emergency, sickening almost 100,000 people worldwide, and so far killing more than 3,000. As of March 3, about 100 cases had been reported in the US, and six people have died.

How does it spread?

Researchers are still trying to understand how SARS-CoV-2 spreads between humans. (SARS-CoV-2 is the official name of the germ; the official name of the disease you get from the germ is Covid-19—more on that below.) It’s likely to be transmitted in droplets from coughing or sneezes, and the virus has a two- to 14-day incubation period. That means people could be infectious for quite a while before symptoms like fever, cough, or shortness of breath emerge.

Right now, CDC officials say Americans should prepare for the worst and hope for the best. Based on the number of new cases, the overall risk of getting Covid-19 is still pretty low in most parts of this country. But flaws in testing kits and strict testing requirements have severely limited how many people have so far been tested, which means nobody knows who might actually be infected, or how serious (or mild) their illnesses might be. Growing numbers of cases of community spread in California and Washington suggest that the virus may be circulating more widely than case numbers might indicate.

What are the particular symptoms of Covid-19?

In the confirmed cases so far, most people get a fever with a dry cough; smaller numbers of folks might experience shortness of breath, a sore throat, or a headache.

How can I avoid catching the coronavirus?

Wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands wash your hands. You get the point.

Clean all of your tech equipment. Just like your hands, your smartphone and keyboard and headphones and anything else gets germs on it.

Are you a health care worker? If not, don't buy a face mask—that depletes supplies for the health professionals who need them. Same goes for gloves (see: "wash your hands," above).

If  you're in a high-risk group (over 60, have preexisting lung disease, heart disease, diabetes, or a weakened immune system) you should seek treatment if you get sick, since it can quickly go from cough to full-blown pneumonia. Call your doctor or clinic first with your suspicions so they can direct you appropriately. If you're not in a high-risk group, better to self-isolate at home with plenty of fluids and anti-fever meds. Odds are you'll recover, and this way you won't expose anyone. Still call your doctor, so they know what's going on—they may be able to direct you to people at the health department who can conduct testing. Don't go to the ER unless you're really experiencing life-threatening symptoms.

Is Covid-19 more deadly than the flu?

That remains to be seen. According to preliminary estimates from the Centers for Disease Control and Prevention, the 2019–2020 flu caused 19 million to 25 million illnesses and up to 25,000 deaths. The Covid-19 numbers are harder to calculate because it’s not yet clear how many people are infected. The CDC calculates the death rate at about 2 percent, which is higher than the flu—but the real number might be a lot lower, because less-severe cases may not have been reported. People with more mild cases might not even go to the hospital, and health care workers might have mistaken cases for the flu or for pneumonia. If epidemiologists count only the most severe cases, the death rate will look higher because a higher proportion of those patients die—so that might not offer an accurate reflection of reality.

The biggest difference between the two types of infection is that the health system is better prepared to fight the flu. It comes every year and, while some strains are more severe than others, doctors know how to treat and prevent it. Covid-19 is uncharted territory, because scientists have so many questions about how it spreads, and there isn’t a vaccine for it. That’s why governments around the world are responding so quickly by discouraging travel to China and quarantining people who may have been exposed. The World Health Organization hasn't officially called Covid-19 a pandemic—it's probably waiting to see if sustained person-to-person transmission happens outside of China. It's looking at Iran, Italy, and South Korea for that.

How did it get its official name?

The international committee tasked with classifying viruses has named the new one SARS-CoV-2, because of its close genetic ties to another coronavirus, the one that causes SARS. However, the disease caused by SARS-CoV-2—remember, that's the disease characterized by coughing, fever, and respiratory distress—is called Covid-19. It's the name officially bestowed upon the ailment by the World Health Organization. WHO's task was to find a name that didn't demonize a particular place, animal, individual, or group of people and which was also pronounceable. It's pronounced just like it sounds: Co-Vid-Nine-teen.

Where did SARS-CoV-2 come from, anyway?

The first cases were identified at the tail end of 2019 in Wuhan, the capital city of China’s Hubei province, when hospitals started seeing patients with severe pneumonia. Like the viruses that cause MERS and SARS, the new coronavirus appears to have originated in bats, but it’s not clear how the virus jumped from bats to humans or where the first infections occurred. Often, pathogens journey through an intermediary “animal reservoir”—bats infect the animals, and humans come into contact with some product from that animal. That could be milk or undercooked meat, or even mucus, urine, or feces. For example, MERS moved to humans through camels, and SARS came through civet cats sold at a live animal market in Guangzhou, China.

Scientists don’t know why some coronaviruses have made that jump while others haven’t. It may be that the viruses haven’t made it to animals that humans interact with, or that the viruses don’t have the right spike proteins, so they can’t attach to our cells. It’s also possible that these jumps happen more often than anyone realizes, but they go unnoticed because they don’t cause serious reactions.

How do coronaviruses even work?

Coronaviruses are divided into four groups called genera: alpha, beta, gamma, and delta. These little invaders are zoonotic, meaning they can spread between animals and humans; gamma and delta coronaviruses mostly infect birds, while alpha and beta mostly reside in mammals.

Researchers first isolated human coronaviruses in the 1960s, and for a long time they were considered pretty mild. Mostly, if you got a coronavirus, you’d end up with a cold. But the most famous coronaviruses are the ones that jumped from animals to humans.

Coronaviruses are made up of one strip of RNA, and that genetic material is surrounded by a membrane studded with little spike proteins. (Under a microscope, those proteins stick up in a ring around the top of the virus, giving it its name—“corona” is Latin for “crown.”) When the virus gets into the body, those spike proteins attach to host cells, and the virus injects that RNA into the cell’s nucleus, hijacking the replication machinery there to make more virus. Infection ensues.

The severity of that infection depends on a couple of factors. One is what part of the body the virus tends to latch onto. Less serious types of coronavirus, like the ones that cause the common cold, tend to attach to cells higher up in the respiratory tract—places like your nose or throat. But their more gnarly relatives attach in the lungs and bronchial tubes, causing more serious infections. The MERS virus, for example, binds to a protein found in the lower respiratory tract and the gastrointestinal tract, so that, in addition to causing respiratory problems, the virus often causes kidney failure.

The other thing that contributes to the severity of the infection is the proteins the virus produces. Different genes mean different proteins; more virulent coronaviruses may have spike proteins that are better at latching onto human cells. Some coronaviruses produce proteins that can fend off the immune system, and when patients have to mount even larger immune responses, they get sicker.

Can people be immune to the new coronavirus?

Viruses that spread quickly usually come with lower mortality rates and vice versa.

As the virus is an entirely new strain, it is believed that there is no existing immunity in anyone it will encounter.

Some level of immunity will naturally develop over time, but this means that those with compromised immune systems, such as the elderly or sick, are most at risk of becoming severely ill or dying from the coronavirus.

Although the total number of deaths has now exceeded those recorded during the 2002-2003 outbreak of severe acute respiratory syndrome (SARS), the current mortality rate is much lower than that of SARS.

The coronavirus mortality rate stands at 2.4 percent, while SARS killed 9.6 percent of those infected.

How can people protect themselves? Are face masks useful?

In terms of self-protection and containing the virus, experts agree that is important to wash your hands frequently and thoroughly with soap; cover your face with a tissue or your elbow when coughing or sneezing; visit a doctor if you have symptoms; and avoid direct contact with live animals in affected areas.

While face masks are popular, scientists doubt their effectiveness against airborne viruses.

Masks may provide some protection to you and others, but because they are loose and made of permeable material, droplets can still pass through.

Many countries have advised people travelling back from China to self-quarantine for at least two weeks.

How to Protect Yourself Against the Coronavirus

Wash your hands.                        

Washing your hands regularly is the best way to protect yourself from the coronavirus — assuming you’re doing it correctly. The CDC recommends getting your hands wet with warm or cold water; lathering your entire hands, including under the nails, with soap; scrubbing your hands for 20 seconds; rinsing with clean water; and finally, either letting your hands air-dry or using a clean towel.

“Wash them especially well if you’re about to eat,” Aaron E. Carroll, a professor of pediatrics at Indiana University School of Medicine, wrote in the New York Times. “Wash them after you’ve blown your nose, coughed or sneezed. Make it routine that all members of the household wash their hands when they get home.”

It’s also not a bad idea to carry around a hand sanitizer for times when you’re not near a sink, though you should make sure it contains at least 60 percent alcohol. However, experts stress that washing your hands thoroughly — and frequently — is the best preventative measure.

Stop touching your face!                        

In addition to washing your hands frequently, the CDC also recommends that you avoid touching your face — specifically, your eyes, nose, and mouth, which are entry portals for coronavirus and other germs. If an infected person coughs or sneezes on a surface, and you touch that contaminated surface and then touch your facial mucous membranes — the eyes, nose, and mouth — you could become infected.

Stock up on prescriptions and household supplies.                        

According to the New York Times, experts are recommending stocking up on at least a month’s worth of prescription or over-the-counter medicine, in the event that you have to self-quarantine. Experts are also advising buying extra shelf-stable food, cleaning supplies, and other necessary household items.

Practice social distancing.                        

If there’s an outbreak in your area, experts say it’s wise to practice “social distancing” measures to mitigate the spread of viruses. These measures typically entail keeping your distance from other people — the CDC recommends standing at least six feet away, if possible — and avoiding crowded spaces. (Some countries like France have already implemented such measures, like banning gatherings of more than 1,000 people.)

 If you’re sick …                        

Be cautious: If you experience any cold or flulike symptoms, you should stay home (if you can afford to.) And even if you aren’t sick, it’s a good idea to work from home if you can. As Katie Heaney noted on the Cut, every time we leave our home, we increase our risk of exposure and transmission, potentially unknowingly.

According to the Times, if you think you have the coronavirus, you should reach out to your doctor or local health department, or follow the instructions on the CDC’s website.

If you’re pregnant …                        

As of now, the CDC does not recommend specific precautions for pregnant women, as there’s a lack of “information from published scientific reports about susceptibility of pregnant women to COVID-19.” However, the CDC notes that because pregnant women’s immune systems are in flux, it’s possible they could be more susceptible. “It makes sense that a pregnant woman would be at higher risk of complications from this virus than a nonpregnant one,” Dr. Steven Gordon, M.D., an infectious-disease specialist at the Cleveland Clinic, told the New York Times last week.

If you have a chronic illness, are elderly, or have a compromised immune system …                        

While COVID-19 will cause mild symptoms in the majority of infected people, Jan Carette, an associate professor at the Department of Microbiology and Immunology at Stanford University’s School of Medicine, says that the elderly — especially those with chronic conditions, like hypertension or diabetes — are at greater risk for more severe disease. In this case, he recommends that those who are especially susceptible practice the above precautions as well as avoid people who display flulike symptoms.

If you’re traveling …                        

If you have upcoming travel plans, it’s a good idea to stay up-to-date on the CDC’s travel warnings for specific countries. In general, it’s safest to avoid nonessential travel to countries with a sustained COVID-19 presence; right now, this includes Iran, China, South Korea, and Italy. For individuals who are especially susceptible to viral infections, including the elderly and those with existing medical conditions, the CDC advises avoiding travel to Japan as well.

Currently, the CDC doesn’t have any additional recommendations for domestic travel, though this could change as the virus spreads further in the United States. But according to the CDC’s website, the risk of infection on an airplane is low. “Because of how air circulates and is filtered on airplanes, most viruses and other germs do not spread easily,” they write. However, they recommend that travelers wash their hands frequently and avoid contact with sick passengers.

10 Tips For Preparing To Stay At Home Due To The Coronavirus

1. You can eat normal, tasty, healthy foods. 

Just because you’re stocking up doesn’t mean you have to live on nonperishable foods and canned vegetables. That’s going to get tiresome real quick, and there are plenty of ways to eat the things you normally would.Fill your freezer with fresh, flavorful soups. Keep pasta in your pantry and tomato sauce in your freezer. Think about the foods you would want to eat on a typical day; usually there’s a way to keep those around. Personally, I froze a big batch of taco soup and a bunch of marinated salmon, and made a crunchy quinoa salad that lasts well in the fridge for the week. I also bought eggs, sweet potatoes, peanut butter, hummus, carrots, and a bunch of other things — normal staples for my diet that will keep for a decent length of time.

2. And remember that food isn’t just about staying alive.

You don’t just need well-balanced meals! You need Cheez-Its, peanut butter cups, popcorn, gummy bears...really whatever snacks you’ll be craving if you’re stuck inside for a while. There has never been a better time to have ingredients around to bake cookies. And if you’re out here thinking meal prep time would be a good time to get super healthy and only eat lentils, get real. These are trying times. Buy the damn candy. 

3. Avoid being too isolated. 

Being forced to stay inside might sound like an introvert’s dream come true, but when it’s in the midst of a worldwide epidemic and everyone is panicking, it’s not such a fun and chill time. It took me one day stuck at home to get lonely and stir-crazy.Check in with your people. Get on the phone or FaceTime and call your family and friends with some regularity — you’ll probably need it, and so will they.

And if someone you know actually gets quarantined, or gets infected with the virus, be there for them as much as you (safely) can. Call them, or just send a playlist, some memes, or links. And even if you can’t go hang out with them IRL, consider cooking them a meal and leaving it outside their door, which is safe to do.“People [need to] know who to call if they do start getting symptoms, [and] know there is somebody who is going to check in on them, that they’re not just going to be isolated and forgotten about,” said Hawryluck. “If you’re afraid you’re going to get sick, what you really need and want is to know that somebody is going to care for you.”

4. Get a little fitness in. 

There are plenty of workouts you can do from the comfort of your own home, and doing so can seriously help your mental health.Here are a bunch of exercises you can do without any equipment, and YouTube has tons of channels that offer instruction in everything from yoga to Pilates to strength training.And if you can still go outside, nothing beats a walk. Just avoid big groups of people.

5. Clean your home.

Not only does it protect against the spread of illness, it also makes being cooped up in your home a lot more pleasant. Here’s a big list of spring cleaning chores you may have been putting off. 

6. Go online, but beware.When the SARS epidemic broke out in 2002, Facebook, Twitter, and even Myspace did not yet exist. Now, people are far more digitally connected, and the ability to keep in touch over social media and video chat can have major benefits on mental health during isolation. “It shortens distances between people,” Hawryluck said.But the internet also creates issues that didn’t exist during SARS — namely, the spread of misinformation.“People are afraid, and that’s okay — we are human, there are things in our lives that are going to scare us, and this is one of them,” said Hawryluck. “But how we handle that fear, I think fear can be lessened if we have accurate information.”Here’s a running list of misinformation about the coronavirus to keep on hand as you peruse social media. Also, be wary of those hawking fake cures online or trying to infect your computer with malware by sending you suspicious coronavirus-themed emails.

7. Plan out your entertainment.

Watch the news, for sure, but don’t just stay glued to cable news. “The worst thing people can do is sit around and watch TV or watch their screens and look for the hourly update of numbers,” Hawryluck said. “I think that just exaggerates the symptoms of fear and its effects.”

You know all those shows and movies you’ve been meaning to watch but never get around to? Make a list — yes, an actual list — of the titles, and you’ll never run out of things to watch.But if spending too much time looking at screens is driving you nuts, shut it down.Get out a bunch of books from your library. Pull out the board games and puzzles. Have some craft supplies on hand, if that’s your thing.

8. Seek professional help if you’re really struggling.Whether you’ve been to a therapist before or are just realizing you might need to see one, seeking help with your mental health doesn’t need to wait till you can go outside again. Lots of therapists offer sessions over the phone or video chat. Here are a bunch of tips for how to find a therapist. There are also apps to help you with your mental health.

9. If you’re working from home, do it right. Working from home sounds like the dream — pajamas all day, slacking off, working from the couch! — but it can get bleak and unproductive pretty quickly if it’s not approached the right way.

10. Remember to stay healthy and practice good hygiene.

Information is power, and having the right info can be helpful in stopping yourself from freaking out. You don’t need to go overboard on research, but it’s a good idea to be aware of what you should do if you do think you’ve contracted the coronavirus.

And perhaps the easiest way to stay healthy is to maintain proper hygiene. You don’t need a face mask (unless you’re sick), but you should be washing your hands regularly (and remember, soap and water is just as effective as hand sanitizer).Once that’s done, just try to take it easy (and maybe order some dumplings to support your favorite Chinese restaurant). These are tough, uncertain times, and the best thing we all can do is be kind to ourselves and our neighbors as we all go through it.

[scifigeneration]

David vs. Goliath: What a tiny electron can tell us about the structure of the universe

by Alexey Petrov

By Royalty-free stock illustration ID: 134556248 Atom. Roman Sigaev/ Shutterstock.com

What is the shape of an electron? If you recall pictures from your high school science books, the answer seems quite clear: an electron is a small ball of negative charge that is smaller than an atom. This, however, is quite far from the truth.

A simple model of an atom with the nucleus of made of protons, which have a positive charge, and neutrons, which are neutral. The electrons, which have a negative charge, orbit the nucleus. Vector FX / Shutterstock.com

The electron is commonly known as one of the main components of atoms making up the world around us. It is the electrons surrounding the nucleus of every atom that determine how chemical reactions proceed. Their uses in industry are abundant: from electronics and welding to imaging and advanced particle accelerators. Recently, however, a physics experiment called Advanced Cold Molecule Electron EDM (ACME) put an electron on the center stage of scientific inquiry. The question that the ACME collaboration tried to address was deceptively simple: What is the shape of an electron?

Classical and quantum shapes?

As far as physicists currently know, electrons have no internal structure – and thus no shape in the classical meaning of this word. In the modern language of particle physics, which tackles the behavior of objects smaller than an atomic nucleus, the fundamental blocks of matter are continuous fluid-like substances known as “quantum fields” that permeate the whole space around us. In this language, an electron is perceived as a quantum, or a particle, of the “electron field.” Knowing this, does it even make sense to talk about an electron’s shape if we cannot see it directly in a microscope – or any other optical device for that matter?

To answer this question we must adapt our definition of shape so it can be used at incredibly small distances, or in other words, in the realm of quantum physics. Seeing different shapes in our macroscopic world really means detecting, with our eyes, the rays of light bouncing off different objects around us.

Simply put, we define shapes by seeing how objects react when we shine light onto them. While this might be a weird way to think about the shapes, it becomes very useful in the subatomic world of quantum particles. It gives us a way to define an electron’s properties such that they mimic how we describe shapes in the classical world.

What replaces the concept of shape in the micro world? Since light is nothing but a combination of oscillating electric and magnetic fields, it would be useful to define quantum properties of an electron that carry information about how it responds to applied electric and magnetic fields. Let’s do that.

This is the apparatus the physicists used to perform the ACME experiment. Harvard Department of Physics, CC BY-NC-SA

Electrons in electric and magnetic fields

As an example, consider the simplest property of an electron: its electric charge. It describes the force – and ultimately, the acceleration the electron would experience – if placed in some external electric field. A similar reaction would be expected from a negatively charged marble – hence the “charged ball” analogy of an electron that is in elementary physics books. This property of an electron – its charge – survives in the quantum world.

Likewise, another “surviving” property of an electron is called the magnetic dipole moment. It tells us how an electron would react to a magnetic field. In this respect, an electron behaves just like a tiny bar magnet, trying to orient itself along the direction of the magnetic field. While it is important to remember not to take those analogies too far, they do help us see why physicists are interested in measuring those quantum properties as accurately as possible.

What quantum property describes the electron’s shape? There are, in fact, several of them. The simplest – and the most useful for physicists – is the one called the electric dipole moment, or EDM.

In classical physics, EDM arises when there is a spatial separation of charges. An electrically charged sphere, which has no separation of charges, has an EDM of zero. But imagine a dumbbell whose weights are oppositely charged, with one side positive and the other negative. In the macroscopic world, this dumbbell would have a non-zero electric dipole moment. If the shape of an object reflects the distribution of its electric charge, it would also imply that the object’s shape would have to be different from spherical. Thus, naively, the EDM would quantify the “dumbbellness” of a macroscopic object.

Electric dipole moment in the quantum world

The story of EDM, however, is very different in the quantum world. There the vacuum around an electron is not empty and still. Rather it is populated by various subatomic particles zapping into virtual existence for short periods of time.

The Standard Model of particle physics has correctly predicted all of these particles. If the ACME experiment discovered that the electron had an EDM, it would suggest there were other particles that had not yet been discovered. Designua/Shutterstock.com

These virtual particles form a “cloud” around an electron. If we shine light onto the electron, some of the light could bounce off the virtual particles in the cloud instead of the electron itself.

This would change the numerical values of the electron’s charge and magnetic and electric dipole moments. Performing very accurate measurements of those quantum properties would tell us how these elusive virtual particles behave when they interact with the electron and if they alter the electron’s EDM.

Most intriguing, among those virtual particles there could be new, unknown species of particles that we have not yet encountered. To see their effect on the electron’s electric dipole moment, we need to compare the result of the measurement to theoretical predictions of the size of the EDM calculated in the currently accepted theory of the Universe, the Standard Model.

So far, the Standard Model accurately described all laboratory measurements that have ever been performed. Yet, it is unable to address many of the most fundamental questions, such as why matter dominates over antimatter throughout the universe. The Standard Model makes a prediction for the electron’s EDM too: it requires it to be so small that ACME would have had no chance of measuring it. But what would have happened if ACME actually detected a non-zero value for the electric dipole moment of the electron?

View of the Large Hadron Collider in its tunnel near Geneva, Switzerland. In the LHC two counter-rotating beams of protons are accelerated and forced to collide, generating various particles. AP Photo/KEYSTONE/Martial Trezzini

Patching the holes in the Standard Model

Theoretical models have been proposed that fix shortcomings of the Standard Model, predicting the existence of new heavy particles. These models may fill in the gaps in our understanding of the universe. To verify such models we need to prove the existence of those new heavy particles. This could be done through large experiments, such as those at the international Large Hadron Collider (LHC) by directly producing new particles in high-energy collisions.

Alternatively, we could see how those new particles alter the charge distribution in the “cloud” and their effect on electron’s EDM. Thus, unambiguous observation of electron’s dipole moment in ACME experiment would prove that new particles are in fact present. That was the goal of the ACME experiment.

This is the reason why a recent article in Nature about the electron caught my attention. Theorists like myself use the results of the measurements of electron’s EDM – along with other measurements of properties of other elementary particles – to help to identify the new particles and make predictions of how they can be better studied. This is done to clarify the role of such particles in our current understanding of the universe.

What should be done to measure the electric dipole moment? We need to find a source of very strong electric field to test an electron’s reaction. One possible source of such fields can be found inside molecules such as thorium monoxide. This is the molecule that ACME used in their experiment. Shining carefully tuned lasers at these molecules, a reading of an electron’s electric dipole moment could be obtained, provided it is not too small.

However, as it turned out, it is. Physicists of the ACME collaboration did not observe the electric dipole moment of an electron – which suggests that its value is too small for their experimental apparatus to detect. This fact has important implications for our understanding of what we could expect from the Large Hadron Collider experiments in the future.

Interestingly, the fact that the ACME collaboration did not observe an EDM actually rules out the existence of heavy new particles that could have been easiest to detect at the LHC. This is a remarkable result for a tabletop-sized experiment that affects both how we would plan direct searches for new particles at the giant Large Hadron Collider, and how we construct theories that describe nature. It is quite amazing that studying something as small as an electron could tell us a lot about the universe.

A short animation describing the physics behind EDM and ACME collaboration’s findings.

About The Author:

Alexey Petrov is a Professor of Physics at Wayne State University

This article is republished from The Conversation under a Creative Commons license. 

[cataracteyesurgeon]

Cataract Treatment and Cataract Surgery In Mumbai - What Is Cataract Surgery ?

What is Cataract?

The opacification of the normal transparent lens is called cataract. The Latin word “Cataracta” means Waterfall – imagine trying to see through a sheet of falling water or through a frosted or fogged up window.

History

Eye with Normal Lens

Eye with Cataract

The earliest surgical treatment for cataract began in India and was called couching. In this procedure the sclera is incised and the lens is dislocated backward into the vitreous and displaced out of the optical axis. This procedure was performed for more than 2000 years until mid-eighteenth century. Great progress in cataract surgery has been made in recent years with the introduction of microsurgical instruments, microscope & modern surgical techniques like phacoemulsification

Lens: The lens consists of the

Capsule

Cortex

Nucleus

The primary function of the lens is to focus light on the retina, while remaining transparent. This transparency depends on maintenance of structural (anatomic) & functional (physiologic) integrity of its cells.

The lens is 66% water, the least hydrated organ of the body, the remaining bulk is composed mainly of protein. It is devoid of any blood supply and derives its nourishment from the surrounding fluid of the eye i.e. aqueous & vitreous.

Common Causes of Cataract

Age related or senile: Occurs as a result of natural ageing process of lens fibers, which become opaque over a period of time.

Traumatic Cataract: Develops as a result of injury to the eye.

Metabolic Cataract: Develops as a result of defect in body metabolism – Diabetes- Calcium disorders.

Toxic Cataract: Certain Toxic Substances or Drugs can lead to cataract if taken for a long time due to any reason. Eg. Steroids Miotics, Chlorpromazine, etc.

Secondary Cataract: develops as a result of some other primary eye disease such as chronic inflammation or glaucoma.

Development of Cataract

Normal Eye

It varies from person to person but as a general rule, most cataracts develop slowly over a period of time. A cataract can take months or even years to reach a point where is adversely affects vision.

How does Cataract affect Normal Lifestyle?

One may not be aware that a cataract is developing if the size and location of the cloudy areas in the lens are not in the Central pupillary area. As the cataract progresses, there is deterioration of distance and reading vision. One may experience hazy and blurred vision. Double vision may also occur when a cataract is beginning to form.

Eye with Cataract

The eye may also be more sensitive to light and glare, making night driving difficult. There may be a need to change the glass prescription in the early stages which may help temporally. As the Cataract develops, stronger glasses would no longer improve the vision. This can lead to imbalance between the two eyes, which may cause headache. One may also experience Poor night vision, poor depth perception e.g. difficulty in getting downstairs.

Are you looking for Cataract Operation, Cataract Treatment or Cataract Surgery in Mumbai City?

If you are looking for Cataract Surgery In Mumbai, Bladeless Lasik in Mumbai or Best Cataract Treatment in Mumbai, Ojas Eye Hospital is here to assist. Ojas Eye Hospital can help with your Cataract surgery procedure, including: Cataract Removal, Cataract Eye Treatments, Refractive Cataract, etc. Ojas Eye Hospital has served many Cataract clients in Mumbai City.

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[as-studypeach]

Cell Membranes: the Bouncers of the Cell

The cell membrane, sometimes called the plasma membrane, surrounds and protects the interior organelles of the cell as well as controlling what goes in and out. Complex cells like eurkaryotes have membranes surrounding their organelles as well.

This image shows the basic structure of a cell membrane, which you have to know in detail for the A Level exam. The basic function is to regulate the movement of substances across them and separate the contents of the cell from its environment. 

As shown, the membrane is not just a single layer - instead, it is comprised of two layers of phospholipids (therefore conveniently called the phospholipid bilayer).

Phospholipid molecules are made from two fatty acid tails and a phosphate head. You will have learnt more about this in earlier units.  These phosphate head are hydrophilic (water-loving) whereas the fatty acid tails are hydrophobic (water-hating). When in water, they orientate themselves so that the heads are facing the water and the tails are away from it. This is how they form their bilayer, with heads out and tails in.

There are other molecules in the membrane. Proteins are embedded in the bilayer. Some span the whole membrane and are called intrinsic proteins, such as channel or carrier proteins, which are needed in transport processes that move substances across the membrane. Others stick out from the membrane surface and only go half way through, therefore called extrinsic proteins. These have specific functions like chemical receptors.

Some proteins and lipids have branches of sugar molecules attached to them. When attached to a lipid, these make glycolipids and when attached to proteins, these make glycoproteins. Sugar molecules are always on the outer surface of the membrane so can interact with arriving molecules, such as hormones or drugs.

Cell membranes also have another lipid-like substance called cholesterol. This provides stability by preventing too much movement of the other molecules in the membrane. Animal cells, rather than plant or prokaryotic cells, usually have the highest amounts of cholesterol.

This membrane structure is not just specific to around the cell. Eurkayotic cells have a phospholipid bilayer with embedded proteins surrounding the endoplasmic reticulum, Golgi apparatus, the nucleus, lyosomes and vacuoles.

The Fluid Mosaic Model is generally accepted as describing how membranes are arranged. 'Fluid' represents how some parts of the membrane can move around freely, if they are not attached to other parts of the cell, such as the phospholipids. ‘Mosaic' part is the mismatched pattern of proteins that is found in the bilayer.

Summary

The basic function of a cell membrane is to regulate the movement of substances across them and separate the contents of the cell from its environment.

It is comprised of two layers of phospholipids (therefore called the phospholipid bilayer).

Phospholipid molecules are made from hydrophobic two fatty acid tails and a hydrophillic phosphate head. When in water, they orientate themselves so that the heads are facing the water and the tails are away from it, forming a bilayer.

Proteins are embedded in the bilayer. Some span the whole membrane and are called intrinsic proteins, such as channel or carrier proteins, needed in transport. Others stick out from the membrane surface and only go half way through, therefore called extrinsic proteins. These have specific functions like chemical receptors.

Some proteins and lipids have branches of sugar molecules attached to them, making glyolipids and glycoproteins. Sugar molecules are always on the outer surface of the membrane so can interact with arriving molecules, such as hormones or drugs.

Cell membranes also have another lipid-like substance called cholesterol which provides stability by preventing too much movement of the other molecules in the membrane.

Eurkayotic cells have a phospholipid bilayer with embedded proteins surrounding the endoplasmic reticulum, Golgi apparatus, the nucleus, lyosomes and vacuoles.

The Fluid Mosaic Model is generally accepted as describing how membranes are arranged. 'Fluid' represents how some parts of the membrane can move around freely, if they are not attached to other parts of the cell, such as the phospholipids. ‘Mosaic' part is the mismatched pattern of proteins that is found in the bilayer.

Happy studying!

[not-so-secret-nerd]

I Can Fix That

Watched Holes and got an idea. All the fluff for you guys.

“I can fix that!”

It was Holtzmann’s preferred mantra since…well, since she’d first closed her little fist around a screwdriver at five and started making “repairs” to appliances around her home. Growing up, her mother heard that more than “I love you”—only slightly more on account Jillian was an affectionate child. It began as something said with a grin that showed too much teeth, a giggle trailing on the end like a kite caught by the wind. Innocent. Welcome. Laughed at during family gatherings and awed at during community functions. It was a novelty.

But childlike innocence was not something long meant for this world. Like snow, the delicate and fragile beauty melted under the heat of forced maturity. Childhood was fleeting. The bumps and tumbles of a child, once seen as amusing or adorable, morphed into annoyances met with sharp reproaches and sometimes sharper hands—depending on the family member. The smiles disappeared, replaced with deep scowls and louder voices.

Holtzmann quickly learned that the playfulness of her mantra had to stop. She couldn’t say it with a confident smile and expect a hand not to fly at her when she took apart her uncle’s TV and forgot to solder the right wires back into place. She couldn’t roll it off her tongue with a giggle when she experimented with her cousin’s dirt bike and wound up with three leftover screws after reassembling the engine—it had caught fire and she’s caught hell for it. And she certainly couldn’t pull off a playful wince when she’d disassembled a washing machine from the inside out and the local laundromat, flooding the tiny building with enough suds to make Mr. Bubble proud.  

“I can fix that,” turned into a plea for more time. For leniency. For forgiveness. Oftentimes pushed from her lips with a blanch in her shoulders and a raised hand to ward off a blow. Sometimes it worked. Sometimes it didn’t. But she always tried. Her mother and father understood. They’d birthed a curious child with curious tendencies, but the world was far less understanding when that same curious creature undid its careful stitching.

So Holtzmann tempered herself—or at least tried to. When she headed off to high school a full two years ahead of her siblings, she tried. Tried to fit in. Tried being just another face in the crowd. But always the curious itch was there, scratched only when she was in shop class birthing new creations hands covered in sawdust or taking apart appliance scraps her father salvaged from dumpsters.

Slowly, Holtzmann’s “I can fix that,” changed from a please to an offer. Her first had come Junior year in high school, a stutter making her kind gesture warble in her throat. The girl had been beautiful. A cheerleader. Of course. Holtz had seen her struggling with her car on the side of the road, steam belching from under the hood like a fog machine.

Her offer was met with wary acceptance. Jillian didn’t take it personally. People usually didn’t take her seriously. She dressed like a thrift store hobo on good days. On bad, she wore the same pair of grease-stained overalls, hair knotted at the nape of her neck, hands and arms stained to the elbows in some type of grime—oil, dirt, grease, transmission fluid…it didn’t matter.  

The beautiful girl relented with a slow nod. Jillian was off like a shot, waving away sweet-smelling steam and spotting the problem in the radiator. A hole. Easily patched. She attempted chatting. Making small talk. She was okay with that, coming across smoother than she felt and leaving women flustered and blushing. It was a game. The cheerleader was no different, but Holtz didn’t overstep where she wanted, keeping the offer of her number firmly lock behind her teeth.

The girl was beautiful.

Her boyfriend was muscular.

Jillian was gay, and she was strange enough as is. She didn’t need a target on her back. Jillian was gay but she wasn’t stupid.

“I can fix that,” got her a job in town at an auto repair shop—the owner was nice enough and the guys kept their distance…mostly—through her senior year, or at least the half she was present for before being swept off to MIT with a full ride under her belt and fresh promise singing in her veins.

Standing on the campus of a school Jillian had never dreamed she’d attend, she felt small. Back in her hometown, she was known—infamous or not. She might have been known as the town crazy, but at least she had a name and people knew of her eccentricities and quirks. They might not have been wanted, but they were tolerated. Here? Here, she was no one and had no fallback. Not yet.

The first time Holtz shouted, “I can fix that!” was in the middle of Dr. Rebecca Gorin’s open lab. One of the senior students had made a tiny—it wasn’t tiny at all—mistake in calculating her current flow and wound up setting her machine and her right arm on fire. Holtz slid in like a ragamuffin firefighter, dousing the girl and the table in extinguishing foam. The machine continued to smoke and fizzle menacingly on the lab table until Jillian did what she did best. She ripped off her gloves, stuck her hands inside, and began fixing.

Five minutes later, a pair of burned hands, and one skirted lab explosion later, Holtzmann was seated in front of a mystified Dr. Gorin nursing her wounds and explaining, in detail, exactly how she’d known what to do when the math surrounding the malfunction would have taken any normal student hours to sort out.

Holtzmann gained a mentor that day and her first real taste of what it meant to be a celebrated engineer.

Over the next few years, there were many instances of “I can fix that!” Sometimes, Holtz was true to her word and mended whatever was broken, making it better than new. Making it stronger. More powerful. More sophisticated. Sometimes, it was a cry of panicked dismay as something melted down, taking all her hard work with it. Sometimes, it was whispered to herself at night when the world became too loud and she felt like all her hands were capable of doing was destroying. It certainly was like that after CERN. After watching the man she’d accidentally locked in the particle accelerator wheeled off by paramedics scrambling to restart his heart. She’d chanted her mantra like a prayer that day—a never-ending breath—up until she was dismissed from the facility and her team in shame.

“I can fix it,” no longer passed Jillian’s lips after her plane ride home. Not for a long, long time. Not even when Gorin took her into her home and tried to nurse her back into “fighting form”. Not after months of broken silence, sleepless night, crippling depression, and dark thoughts better left untouched. Not until she met a wonderful researcher working out of a rinky-dink lab at Higgins Institute of Science desperately searching for a research partner.

Holtzmann had dared to hope that day—standing in the door to the lab with her duffel on her shoulder—and that hope turned into the wildest ride of her life.

“I can fix that,” slowly started coming back to the woman. First quietly then more assertively as she found her footing. Abby was kind, caring, and most importantly patient. She loved Holtzmann’s “fixes” and oftentimes joined her in the work. For the first time, Jillian could admit aloud she had a true friend, and together they struck off into a field no one took seriously. Into the paranormal. Into the void. Into the unknown.

Five years and one hell of a New York paranormal event later that unknown birthed the Ghostbusters and a new family for Holtzmann, one she never imagined she’d possess. One so unlike her own family but oh so similar. One that was her all and everything, strange and slightly broken though it may be.

“I can fix that,” became a daily thing. Between repairing and refurbishing old tech and creating new tools and weapons for the ‘busters, Jillian’s days were filled with unlimited opportunities to show the stretch her creative muscle.

“I can fix that,” was said with a shrug and a smile, or a frown and a scratch to the back of her head. It was muttered over equipment, into bunches of wires, into the white-hot nucleus of a welding arc. It was spoken cheerily from the alley when she and her colleagues tested new equipment and the technical bugs made themselves known. Sometimes it was even snorted through shaking laughter when clearing slime away from Erin’s face.        

Erin. Now there was a conundrum Holtzmann couldn’t solve. It wasn’t for lack of trying. She was ace at taking things apart as much as she was at fixing them. After all, you learned to fix through disassembly. But her disassembly of Erin left her with too many pieces left over. Parts she knew went somewhere, but for the life of her she couldn’t puzzle it out. Whenever a step forward was taken Erin would shift directions, making Holtz recalibrate herself, reworking the math in her head. But it was a challenge the engineer reveled in because what kind of scientist would Holtzmann be if she left this puzzle where it lay and didn’t try her hardest to crack the code?

Birthed from curiosity and tempered in the fires of intrigue came something altogether foreign to the engineer. Yes, Jillian had been interested in women in the past. She’d bedded quite a few. Even lasted in a smattering of what would be considered “relationships” for a time, so there was no awakening to be had here for her part, but the subtle curiosity she felt towards Erin—the befuddlement left behind when her flirting wasn’t received or the rare but welcome half-smile gifted by the physicist—morphed into something altogether sharper, deeper, and warm.

“I can fix that,” quickly became a code word for three unspoken words. Holtz would find reasons to say it to Erin as much as possible.

A broken whiteboard? “I can fix that.”

Proton gun malfunction? “I can fix that.”

Slime in the eyes? “I can fix that.”

Cut arm from a bad bust? “I can fix that.”

Sniffles from a fall cold? “I can fix that.”

Each line delivered as the situation dictated but always flavored with a little more. Maybe a kinder smile or a heartier laugh. Maybe a wink—those always got her a blush from the physicist which was a win for the day. Maybe a slow, easy nod.

Intrigue became need became want and desire. This wasn’t a game anymore. For the first time. Holtzmann actively wanted to understand Erin, to get inside her head, to be something more than just a colleague and friend. It was selfish, Jillian knew. She was gay and proud. Erin…well, there was a lot about Erin she didn’t know. Too many variables to consider. Too many places where her hypotheses could be terribly wrong and no amount of “I can fix that!” would mend the broken trust. So Holtz went about her life as if it didn’t kill her inside watching Erin from the safe length of friend. She wouldn’t disassemble this woman. It wasn’t her place. It wasn’t mutually wanted. Holtz could respect that but there was never an “I can fix that,” far from her lips.

So the night she’d come back to the firehouse—mind abuzz with modifications their proton packs were in sore need of—and found Erin hunched on the couch, Holtzmann knew in her heart of hearts that someone else’s disassembly had been done to the woman. Disassembly. It sounded so clean and orderly. There was nothing orderly about the tears leaving long streaks down Erin’s pale face, dripping off her chin when her head shot up and her glowing blue eyes caught Jillian’s. There was nothing clean about the broken fragments of her heart she cradled to her chest, freshly smashed by the man—an old colleague—she’d attempted to rekindle a relationship with. Everything about Erin was damaged and broken and fragmented, cracked and ripped and smashed to pieces, and Holtz felt something hot floor her veins.

Carefully, she set her duffle down and walked towards the woman who looked away in shame. Erin wouldn’t raise her eyes. No willingly, and Holtz was loath to make her, but tonight was different.

Standing in front of the seated brunette was the only time Jillian was taller than Erin. The juxtaposition wasn’t off-putting. In fact, it worked in her favor. With gentle hands, Holtzmann lifted Erin’s face. The physicist went willingly. She didn’t blanch when Holtz’s thumb swept across her cheek to clear away an errant tear. She didn’t draw back from the intimate closeness of their bodies. Didn’t move. Because Jillian was looking at her in a way no one else had. She wasn’t looking at Erin for what she could be. What she would be once she picked herself back up and hastily glued her broken self together and soldiered on like always. Holtzmann was looking at her as she was: broken, disassembled, ruined. She was looking at the fragments and puzzling out their placement, piecing the woman back together in her mind.

Mending. Fixing. Healing.

“I can fix that.”  

It was barely a breath across her teeth, but Erin heard it as clearly as if she’d shouted. And suddenly there was molten metal flowing through her cracks and breaks, scalding her to her core, bringing the tears afresh. Not because she was hurting. She was, but healing was a painful process. At least, it always had been up until now because in that moment Erin realized like a thunderbolt to the heart what Holtzmann had been saying to her since their first meeting.

“I can fix that,” was just a roundabout way of saying, “I love you.”

The moment held for a heartbeat more until Holtz shattered the stunned stagnation by bringing their lips together. No crashing bodies. No hungry pawing. No insatiable lust. This was gentle and careful. So careful, and oh so powerful. Like colliding black holes, the mass of their gravity stalling time and space, bending it around them to fit their whims and needs. Suddenly, there’s iron forming in Erin’s unraveling star, whipping the frenzied sensations within her body into a supernova.

When at last they separate, Holtzmann had taken a seat on the coffee table in front of Erin. Though their lips aren’t touching, the physicist feels the engineer’s right hand resting over her heart like she was holding it together with her flesh and blood alone.  

“I can fix this,” she says, looking at her hand for emphasis.

Without breaking eye contact, Erin covers Holtz’s hand with her own, daring herself to take the plunge into territory she’d been anxiously terrified about entering until now.

“I love you too,” she whispers with a tearful smile that’s met with a thousand watt grin.

[crystalcell]

Old Ch1 wip

This is an older version of my first chapter that I plan on revamping in the future.

Enjoy!

---------

The world was a dark and empty place. It was because only so much could be filled at a time, and that made the world both serene and lonesome. Sometimes I dreamt about simply floating through the void like I was just some asteroid myself. 

But the nothingness around me would probably be soul-crushingly lonely, so the dream almost always implodes on itself as my mind begins to think about all the things that could happen in empty space.

———————

My day begins with the tune of flutes coming from my alarm clock speakers, the gentle sounds both sudden enough to wake me and soothing enough to, ironically, not be too alarming.

I reflexively hit the 'snooze' button as I finally begin to process my surroundings. When my brain catches up with my body, I turn my alarm off properly, but the bed's too comfy to leave. I don't really attempt to break free from the soft embrace of my bed covers, sinking further into the synthetic fabric. It's only when I hear the louder sound of a bell that I begin to actually wake up.

"Rise and shine, Aóde!" The cheery synthesized voice almost seems to vibrate through the walls of my room. "Don't want you to be late for school!"

Ah yes. School.

It is indeed a school, but at the same time, it really isn't.

It was originally my idea to attend an actual learning facility, but it's recently become more of a hassle than it's worth. My parents aren't too keen on me abandoning my only real chance to interact with the world outside our house and the doctor that easily, but I'm not sure if I'll ever be ready to experience the world outside like others do.

I found myself finally out of bed, stumbling towards my bathroom as I prepared to look alive. When I make it to the bathroom, I take a good look at myself in the mirror, to see if I looked like a disaster or not. My membrane is a bit foggy, making it a grayer shade of blue than it should be, and my cilia are all out of place. But with the help of a brush, I  can get most of it under control.

I start to run the water to the shower, washing away grime and flakes with liquid soap and a brush. The water dribbles out from the showerhead, running over my head and off my body. I intently watch it go down the drain as I'm lost in thought, and yet my mind is empty. When the time finally comes back to me and realize I need to actually leave, I dry off and get dressed, and prepare to eat breakfast.

Sitting at the table was my meal for the day, as my parents had already left for work sometime before. Today, breakfast is a sweet fiber bake and carbohydrate spread with eggs and a glass of dihydrogen monoxide, or water, for those not in the mood to be facetious. I eat it up like I hadn't had anything in cycles, down my immuno-suppression pills with a heavy swig and prepare my supplies for school. I wave goodbye to my parent, but I know it'll only be a few hours 'till we see each other again.

I turn on my comm, and class begins.

"Hello, class! And welcome to today's lesson: Anatomy!" Prof. Derad's cheery voice bursts from the speakers, dripping with enthusiasm. The screen itself displays the colorful caricatures of a homon person and various recognizable organelles like the nucleus and mitochondria, all dancing to the upbeat tune that plays in the background.

[yay] one of my classmates, named Erec apparently, comments with more dubious amounts of enthusiasm. Perhaps the jaunty music already got to that one.

"Yes, it's very exciting, isn't it?" Prof. Derad says with a laugh before continuing with the lesson.

"Now we all know that every living is made up of cells, just how you and I are cells ourselves. But what's inside all of us? Well..."

It goes on to talk about the various organelles and parts within a given homon body, though leaves out a bit to still have material for the week. We're treated to class activity similar to jeopardy that isn't super hard but still pretty fun. My team gets pretty far, but our competition wins by a landslide near the end. It was all in good fun, though I'm sure others are at least a little salty about it.

When its time for the first break of the day, I get up to make myself a sandwich, cutting several slices of protein filament and a few bits of lactose while I watch an episode of something I've been hooked on for the past week.

The classes are, as usual, somewhat dull lectures bolstered by much more engaging labs about what we're currently learning about in biology, such as how much cytoplasm a given homon has, a more complex lesson on the function of various important organelles, and we even watch a little video on the complexities of Homo ambiguus biology.

When the day is over, we're given homework to label and name the organelles in the homon body and state their purpose. It's not particularly difficult, but I check my books just to make sure I didn't mix the vesticles with standard vacuoles and get it done within an hour. Most of the work was done by a computer, but it's not like they could tell. Hopefully.

When I'm finished, I go downstairs to clean up the 'debris' left from me snacking all day. It's as soon as I've put away dishes that the home phone begins to ring.

"Hello!" I say as I answer the call

"Hey, Aode!

M. Sahline: "Hey, Aode! How's your day been?"

Aode: "Yeah, it's been good."

Aode: "So, how soon 'till you're here?"

M. Sahline: "Probably in twenty minutes."

Aode: "I'll be ready by then. See you then!"

M. Sahline: "See you then. Goodbye."

---------------

"Doctor's visit?"

"Doctor's visit."

With a sigh, I begin to put on my personal shell, it's uncomfortable tightness and chill hugging at my membrane as stick on each plate. I put on my favorite white sweater and blue shorts over my protective black gloves and tights. As someone who could kill with a single drop of cytoplasm, I and my parents aren't willing to take any risks.

------------

I wait in my room for the time being, staring out at the blue sky watching the tails of ships coming into orbit and far away satellites dance around the planet. The window is just slightly open, letting in some fresh air I was long overdue for.

Their car comes along just a bit later than usual, but the weather is perfectly fine—a gentle breeze lets the long sleeves of my sweater sway in the wind, and rays from the sun warm the cilia strands on my head.

------------

As we drive, I absent-mindedly watch the people that drive by us and that traverse the walkways. I even see somebody who looked like the most conspicuous person I've seen outside of movies. Maybe they're filming something nearby.

—————

The clinic isn't a particularly large building but is extremely well-staffed. But even though I've been going here for years, I was never that close to any of them. I think I was back when I was younger, but they kept talking down to me like I was five even when I was fourteen and the closeness just faded from age eleven onward.

—————-------------

"Now I'm taking a cytoplasm-sample."

I barely even cringe as the needle penetrates my membrane. I watch the blue fluid enter the syringe as I have countless times before with a detached interest. But underneath that boredom is a primal fear that I can never truly escape from. All it would take is enough of my bodily fluids to come in contact with another person's surface, and death would surely follow.

Though as I watch Dr. Kana work, I can't help but notice something is off.

"Are you alright?" I ask tentatively, trying to overcome my desire to at least give the doctor a gentle pat on the shoulder.

"No, everything's fine," Kana says quickly, "It's just been a long day's all it is."

-------------

The injection by the doctor is rougher than the one from before, stinging slightly.

I hold my arm tightly, though I let go after a few moments to let the doctor bandage it.

But the moment never comes.

I begin to feel tired, and the last thing I see is the face of Dr. Kana tearing up before everything goes black.

[thecoroutfitters]

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[ntrending]

Everything you need to know about uranium

New Post has been published on https://nexcraft.co/everything-you-need-to-know-about-uranium/

Everything you need to know about uranium

Yellowcake uranium. (Nuclear Regulatory Commission via Flickr/)

Since the German chemist Martin Heinrich Klaproth identified uranium in 1789, atomic number 92 has become one of the most troubling substances on the planet. It’s naturally radioactive, but its isotope uranium-235 also happens to be fissile, as Nazi nuclear chemists learned in 1938, when they did the impossible and split a uranium nucleus in two. American physicists at U.C. Berkeley were soon to discover they could force uranium-238 to decay into plutonium-239; the substance has since been used in weapons and power plants around the world. Today, the element continues to stoke international tensions as Iran stockpiles uranium in defiance of an earlier treaty, and North Korea’s “Rocket Man” leader Kim Jong-un continues to resist denuclearization.

But what is uranium, exactly? And what do you need to know about it beyond the red-hot headlines? Here we answer your most pressing nuclear questions:

Where does uranium come from?

Uranium is a common metal. “It can be found in minute quantities in most rocks, soils, and waters,” geologist Dana Ulmer-Scholle writes in an explainer from the New Mexico Bureau of Geology and Mineral Resources. But finding richer deposits—the ones with concentrated uranium actually worth mining—is more difficult.

When engineers find a promising seam, they mine the uranium ore. “It’s not people with pickaxes anymore,” says Jerry Peterson, a physicist at the University of Colorado, Boulder. These days, it comes from leaching, which Peterson describes as pouring “basically PepsiCola—slightly acidic” down into the ground and pumping the liquid up from an adjacent hole. As the fluid percolate through the deposit, it separates out the uranium for harvesting.

Uranium ore. (Deposit Photos/)

What are the different types of uranium?

Uranium has several important isotopes—different flavors of the same substance that vary only in their neutron count (also called atomic mass). The most common is uranium-238, which accounts for 99 percent of the element’s presence on Earth. The least common isotope is uranium-234, which forms as uranium-238 decays. Neither of these products are fissile, meaning their atoms don’t easily split, so they can’t sustain a nuclear chain reaction.

That’s what makes the isotope uranium-235 so special—it’s fissile, so with a bit of finessing, it can support a nuclear chain reaction, making it ideal for nuclear power plants and weapons manufacturing. But more on that later.

There’s also uranium-233. It’s another fissile product, but its origins are totally different. It’s a product of thorium, a metallic chemical much more abundant than uranium. If nuclear physicists expose thorium-232 to neutrons, the thorium is liable to absorb a neutron, causing the material to decay into uranium-233.

Just as you can turn thorium into uranium, you can turn uranium into plutonium. Even the process is similar: Expose abundant uranium-238 to neutrons, and it will absorb one, eventually causing it to decay to plutonium-239, another fissile substance that’s been used to create nuclear energy and weapons. Whereas uranium is abundant in nature, plutonium is really only seen in the lab, though it can occur naturally alongside uranium.

How do you go from a rock to a nuclear fuel source?

People don’t exactly lay out step-by-step guides to refining nuclear materials. But Peterson got pretty close. After you’ve extracted uranium from the earth, he says chemical engineers separate the uranium-rich liquid from other minerals in the sample. When the resulting uranium oxide dries, it’s the color of semolina flour, hence the nickname “yellowcake” for this intermediate product.

From there, a plant can purchase a pound of yellowcake for $20 or $30. They mix the powder with hydrofluoric acid. The resulting gas is spun in a centrifuge to separate from uranium-238 and uranium-235. This process is called “enrichment.” Instead of the natural concentration of 0.7 percent, nuclear power plants want a product that’s enriched to between 3 and 5 percent uranium-235. For a weapon, you need much more: These days, upwards of 90 percent is the goal.

Once that uranium is enriched, power plant operators pair it with a moderator, like water, that slows down the neutrons in the uranium. This increases the probability of a consistent chain reaction. When your reaction is finally underway, each individual neutron will transform into 2.4 neutrons, and so on, creating energy all the while.

Uranium glass dinnerware. (Deposit Photos/)

Any fun facts I should take with me to my next dinner party?

Try this: In PopSci‘s “Danger” issue earlier this year, David Meier, a research scientist at Pacific Northwest National Lab, talked about his work to create a database of plutonium sources. Turns out, every plutonium product has a visible origin story, because “there’s not one way of processing it,” Meier says. The United States had two plutonium production sites. While the intermediate product from Hanford, Washington (the Manhattan Project site from which PNNL grew) was brown and yellow, the Savannah River site in Akon, South Carolina, produced “a nice blue material,” Meier says. Law enforcement officials hope these subtle differences—which may also correspond to changes in the chemical signature, particle size, or shape of the material—will one day help them track down illicit nuclear development.

Or, dazzle your guests with a short history of radioactive dinnerware. The manufacture of uranium glass, also called canary glass or Vaseline glass began in the 1830s. Before William Henry Perkin created the first synthetic color in 1856, dyes were terribly expensive and even then they didn’t last. Uranium became a popular way to give plates, vases, and glasses a deep yellow or minty green tinge. But put these household objects under a UV light and they all fluoresce a shocking neon chartreuse. Fortunately for the avid collectors who actively trade in uranium glass, most of these objects aren’t so radioactive as to pose a risk to human health.

Last one: In 2002, the medical journal The Lancet published an article on the concerning potential for depleted uranium—the waste leftover after uranium-235 extraction—to end up on the battlefield. The concern is that its high density would make it an incredible projectile, capable of piercing even the most well-enforced battle tank. Worse yet, it could then contaminate the surrounding landscape and anyone it.

Written By Eleanor Cummins

[remedialmassage]

What You Need to Know About Fascia

Discover the connective-tissue net that weaves your entire body—which is greater than the sum of its anatomical parts—into one integrated whole.

If I asked you what a heart is like, chances are you’d say it’s like a pump. The lungs are often described as “bellows,” the kidneys “a filter,” the brain “a computer.” We tend to view the body in mechanical terms because we live in an industrial age—and because the body has been described as a “soft machine” ever since the scientist René Descartes coined the term in the early 17th century.

So it comes as no surprise that most anatomy books show you body parts—this muscle, that ligament—as if we’re assembled part by part like a car or an iPhone. But instead of timing belts and motherboards, we have hamstrings and biceps. An anatomy atlas is a helpful tool for learning, but the error comes when we start thinking that humans are actually built that way. What is actually going on under your skin is so different from what’s in those pictures.

Your body is much more like a plant than a machine. We are grown from a tiny seed—a single cell, or fertilized ovum, about the size of a pin prick—not glued together in parts. This seed contains sufficient instructions (given the proper nourishment) to create a helpless, squalling baby, who turns into an energetic toddler, a feckless teenager, and then finally a mature adult.

By the time we’re adults, we consist of approximately 70 trillion cells, all surrounded by a fluid fascial network—a kind of sticky yet greasy fabric that both holds us firmly together, yet constantly and miraculously adjusts to accommodate our every movement.

The traditional biomechanical theory of the musculoskeletal system says that muscles attach to bones via tendons that cross the joints and pull bones toward each other, restricted by other “machine parts” called ligaments. But all these anatomical terms, and the separations they imply, are false. No ligaments exist on their own; instead they blend into the periosteum—vascular connective tissue that serves as cling-wrap around the bones—and the surrounding muscles and fascial sheets. What this means is that you weren’t assembled in different places and glued together—rather, all your parts grew up together within the glue.

For example, the triceps are wedded by fascial fabric to their neighboring muscles north, south, east, and west, as well as to the ligaments deep in both the shoulder and elbow. If you contract the triceps in Plank Pose, all these other structures will have an effect and be affected. Your whole body engages in the action—not just your triceps, pectoral, and abdominal muscles.

The takeaway for yoga? When you do poses, it is useful to put your attention anywhere and everywhere in your body—not just the obviously stretched and singing bits. A release in your foot can help your hip; a change of your hand position can ease your neck. 

See also Fascia: The Flexibility Factor You're Probably Missing on the Mat

Fascial Function

The fluid fascial network that lives between each cell in your body consists of bungee cord–like fibers made mostly from collagen, including reticulin, and elastin. These fibers run everywhere—denser in certain areas such as tendons and cartilage, and looser in others like breasts or the pancreas.

The other half of the fascial network is a gel-like web of variable mucopolysaccharides, or mucus. Basically, your cells are glued together with snot, which is everywhere, and is more or less watery (hydrated) depending on where it is in the body and what condition it’s in.

All the circulation in your body has to pass through these fibrous and mucousy webs. Generally speaking, the denser the fibers and the drier the mucous, the less the fascial web allows molecules to flow through it—nourishment in one direction and waste in the other. Yoga helps both stretch and ease the fiber webbing, as well as hydrate the gel, making it more permeable.

New research shows that this web of proteins runs down through the membranes of each cell and connects both aspects of the connective-tissue web through the cytoskeleton to the cell nucleus. This means that when you’re doing yoga stretches, you are actually pulling on your cells’ DNA and changing how it expresses itself. Thus, the mechanical environment around your cells can alter the way your genes function.

We’ve known for a while that the chemical environment (hormones, diet, stress catecholamines, and more) can do this, but these new connections explain some of the deeper changes we see when people start practicing regularly.

More on that mechanical environment: Cells are never more than four deep from your capillaries, which excrete food, oxygen, messenger molecules (neuropeptides like endorphins), and more. Tension in your body—slumping your shoulders forward, for example—prompts the fibroblasts (the most common cells found in connective tissue) to make more fibers that will arrange themselves along the line of stress. These bulked-up fascial fibers will form a barrier that will slow or stop capillary-sourced food from reaching your cells. You’ll get enough to survive, but function will slow down. In addition to a thicker barrier of fascial-tissue fibers, the mucus that completes your fluid fascial network will also become thicker and more turgid, which contributes to stopping the flow to your cells.

And because the exchange of goods from capillaries to cells is a two-way street, with cells delivering messenger molecules and CO2 and other waste products back into the bloodstream, a hardened fascial network can trap unprocessed cell products (toxins or metabolites) like a stream eddy traps leaves.

The fix: deep strengthening and stretching squeezes your fascial network the way you would squeeze a sponge. Those metabolites that were trapped in the mucousy bits rush in hoards to the capillaries and your bloodstream. Many of us may feel out of sorts after we release deeply held tension—that’s your liver dealing with the metabolites you squeezed from the tissues. Try an Epsom salts bath, or go back for more movement to keep the process going.

Over yoga time, fascial fibers will slowly thin out and unadhere over weeks, sometimes months, but the mucus can change to a more liquid state in as quickly as a minute, allowing more sliding, less pain, more feeling, and less resistance. Use your yoga—it’s a great tool to get fluids and information flowing to their maximum sensitivity and adaptability.  

See also The Anatomy of Fascia—& What It Can Tell Us About How to Practice

Body of Knowledge: Fascia 101

Fascia is the biological fabric that holds us together—the connective-tissue network. This collagenous network of gel and fiber is made up in part by an “extra-cellular matrix,” manufactured inside a connective-tissue cell and then extruded out into intercellular space. The fiber-gel matrix remains an immediate part of the environment of every cell, similar to how cellulose helps provide structure to plant cells. (Remember, we are more like a plant than a machine.)

The Anatomy Trains body map shows our myofascial, or muscle-fascia, anatomy. These 12 whole-body myofascial meridians are more evident in dissection. While most anatomy textbooks show the muscles with the filmy fascia removed, this map illustrates fascia’s deeper function—as global lines of tension, proprioception, and interoception that embed the body’s neuromuscular network, acting to keep your skeleton in shape, guide movement, and coordinate postural patterns. Understanding how these lines function can help unlock a deeper understanding of anatomy for your yoga practice. For example, in Urdhva Mukha Svanasana (Upward-Facing Dog Pose), you are stretching the entire superficial front lines of fascia—the green lines—from the tops of your feet all the way up to the sides of your neck to the back of your skull. You are also challenging all four arm lines. When you strike the right balance in this pose, you can feel your fascial web helping you realize tension and stability, effort and ease. 

Feel Your Fascia

The benefits of thinking of the body as a whole organism, instead of in parts, are profound. When we truly comprehend and feel this in our own bodies and see it in our students, we can move and teach with more integrity. That said, as yoga becomes physiotherapized, or made into a practice resembling physical therapy that helps people restore movement and function (a necessary and positive process in general), asana are often reduced to which muscles are stretched—think “Downward Dog is good for your hamstrings.” In reality, while tight hamstrings may be a common experience, your edge in this pose may be deep in your calves or butt, or along the fronts of your shoulders. It depends on your patterns—the way you were grown and what you took on.

Try this exercise to help you feel that your anatomy is more like a plant than a machine, and to help you move away from separating yourself into parts:

INSTRUCTION

Move into Down Dog. It is easy to feel your back body in this pose as you lift your hips, drop your heels from the middle of your legs, and lengthen your spine. But take time to spread your awareness and attention throughout your entire body in order to find points that lack awareness and are unique to your experience of this pose. Here are some points to ponder:

Track the front of your spine in this pose, as if you were rolling a warm red ball up the front of your spine from your tailbone, up the front of your sacrum and the lumbar and thoracic vertebrae, then behind your guts and heart.

Relax your voice box, then your tongue, then your jaw. Let your head dangle. Let yourself be stupid for a moment, then re-establish the length in your cervical spine without the tension.

Move your breath into the back of your ribs, which can be frozen in your early work in this pose. Can you feel the ribs moving under your shoulder blades? Are you moving your lower ribs behind your kidneys?

Move your weight around your feet while in the pose. This can be subtle but powerful. If your heels are off the ground, move slowly, medially then laterally, on the balls of your feet. Feel how that changes the way you feel the rest of your body. If your heels are down, move slowly all around your feet like a clock: At what position do you lock up? Work there.

Because the deep lateral rotators are often limiting in this pose, can you let the area between your sits bones bloom? Try rotating your knees inward in the pose to help find your limitation, and keep working your hips upward. Remember, you are whole. Someone may describe you as a machine, but that is not the scientific truth­—wholeness is.

Join Tom Myers for a seven-week online introduction to anatomy for yoga students and teachers. You’ll learn how to think of movement in holistic, relational, and practical ways, and how to identify common postural patterns, as well as strategies for cueing to awaken parts of the body that may need work. Sign up now.

About Our ProWriter Tom Myers is the author of Anatomy Trains and the co-author of Fascial Release for Structural Balance. He has also produced more than 35 DVDs and numerous webinars on visual assessment, Fascial Release Technique, and the applications of fascial research. Myers, an integrative manual therapist with 40 years of experience, is a member of the International Association of Structural Integrators and the Health Advisory Board for Equinox. Learn more at anatomytrains.com.

from Yoga Journal http://ift.tt/2rjeZMh

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Barium

Named after the Greek word barys for "heavy," barium is a relatively dense and reactive alkaline earth metal. It is only found naturally when combined with other elements, and compounds containing barium have a wide range of uses; they are found in rat poison, weighting agents in oil drilling fluids, and the white fluid used to visualize intestines in an x-ray diagnostic test called a barium enema.

Just the facts

Atomic number (number of protons in the nucleus): 56

Atomic symbol (on the periodic table of elements): Ba

Atomic weight (average mass of the atom): 137.327

Density: 2.09 ounces per cubic inch (3.62 grams per cubic cm)

Phase at room temperature: solid

Melting point: 1,341 degrees Fahrenheit (727 degrees Celsius)

Boiling point: 3,447 F (1,897 C)

Number of natural isotopes (atoms of the same element with a different number of neutrons): 7

Most common isotope: Ba-138

Discovery of barium

Vincenzo Casciarolo, a 17th-century Italian alchemist, first noticed barium in the form of unusual pebbles that glowed for years after exposure to heat, according to the Royal Society of Chemistry. He named these pebbles "Bologna stones" after his hometown, but they were later determined to be barium sulfate (BaSO4). In the late 18th century, barium oxide (BaO) and barium carbonate (BaCO3) were discovered by German chemist Carl Scheele and English chemist William Withering, respectively.

Pure barium metal was not isolated and identified until 1808 at the Royal Institution in London. The prominent chemist and inventor Sir Humphry Davy used electrolysis to separate the barium from molten barium salts such as barium hydroxide (Ba(OH)2). During electrolysis, an electric current is run through the ionic substance in order to separate ions from each other. Because the barium salts were molten, the barium ions easily moved to the container with the negative electrode, and the other negative ions easily moved in the opposite direction to the container with the positive electrode.

Sources of barium

Barium is found naturally only in combination with other elements because of its high level of reactivity. Barium is most commonly found combined with sulfate and carbonate, but can also form compounds with hydroxide, chloride, nitrate, chlorate, and other negative ions. About 0.05 percent of Earth's crust is barium, making it the 17th most abundant element in the crust, according to Robert E. Krebs in his book, "The History and Use of Our Earth’s Chemical Elements: A Reference Guide" (Greenwood Publishing Group, 2006). Mining reserves in the United Kingdom, Italy, Czech Republic, United States and Germany contain over 400 million tons of barium, according to John Emsley in his book, "Nature’s Building Blocks: An A-Z Guide to the Elements" (Oxford University Press, 1999).

In order to obtain pure elemental barium, it must be separated from other elements present in naturally occurring barium compounds. Barium can be extracted from barium chloride through electrolysis. Barium can also be obtained by reducing barium oxide using aluminum or silicon in a high-temperature, low-pressure vacuum.

Properties of barium

Pure barium is a soft, silvery white metal. Classified as an alkaline earth metal, it is located in group, or column, 2 on the periodic table, along with beryllium, magnesium, calcium, strontium and radium. Each of their atoms contains two valence (outermost) electrons. Barium is in period, or row, 5, so it holds its valence electrons in its fifth shell and can lose the electrons, or become oxidized, very easily. This accounts for barium's high level of reactivity especially with electronegative elements like oxygen.

Commercial uses of barium

Elemental barium does not have many practical uses, again due to its high level of reactivity. However, its strong attraction to oxygen makes it useful as a "getter" to remove the last traces of air in vacuum tubes. Pure barium can also be combined with other metals to form alloys that are used to make machine elements such as bearings or spark plugs in internal combustion engines. Because barium has a loose hold on its electrons, its alloys emit electrons easily when heated and improve the efficiency of the spark plugs, according to Krebs.

Compounds containing barium have a variety of commercial uses. Barium sulfate, or barite, is used in lithopone (a brightening pigment in printer paper and paint), oil well drilling fluids, glassmaking and creating rubber. Barium carbonate is used as a rat poison, and barium nitrate and barium chlorate produce green colors in fireworks.

Barium in your body

The average adult contains about 22 mg of barium because it is present in foods such as carrots, onions, lettuce, beans, and cereal grains. Barium levels in your teeth can actually help scientists determine when babies transition from breast-feeding to eating solid foods. These low levels of barium serve no biological role and are not harmful.

However, large quantities of soluble barium salts can be toxic and even deadly, according to John Emsley in his book "The Elements of Murder: A History of Poison" (Oxford University Press, 2005). Barium can cause vomiting, colic, diarrhea, tremors and paralysis. There have been a handful of murders with barium compounds, including a 1994 murder of a man in Mansfield, Texas, by his 16-year-old daughter, Marie Robards, who stole barium acetate from her high school chemistry laboratory. Several patients were also accidentally killed by barium when soluble barium carbonate rather than insoluble barium sulfate was mistakenly used during a gastroenterological (GI) diagnostic test called a barium enema.

Doctors perform barium enemas in order to visualize and diagnose abnormalities of the large intestine and rectum, according to Johns Hopkins Medicine. During the procedure, barium sulfate is instilled via the rectum to coat the inner walls of the large intestine. Air is typically administered next to make sure the barium coating fills all surface abnormalities. Then, X-raysare used to produce an image of the lower GI tract. Barium sulfate absorbs X-rays and appears white on the X-ray film, in contrast to the air and surrounding tissue that appear black. Analysis of the X-ray image from the barium enema enables physicians to diagnose disorders such as ulcerative colitis, Crohn's disease, polyps, cancer, and irritable bowel syndrome.

Additional resources

Here is more info on barium from the Los Alamos National Laboratory.

Here is what the Jefferson Lab says about barium.

The Royal Society of Chemistry also weighs in about barium.

Source: https://www.livescience.com/37581-barium.html

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chapter 2 for physiology

cell theory: the cell is the smallest unit capable of carrying out life processes, the functional activities of each cell depend on the specific structural properties of the cell, cells are the living building blocks of all multicellular organisms, an organism’s structure and function depend on the structure and function of its cells, all old and new life arise from only preexisting cells, and because of this the cells of all organisms are similar in structure and function

most cells have three things: the plasma membrane (encloses the cells), the nucleus (contains the cell’s genetic material) and the cytoplasm (the portion of the cell’s interior not occupied by the nucleus)

the plasma membrane encloses each cell, is made of lipids, and has proteins in it. its main function is to keep the ICF from mingling with the ECF, and to use its proteins to let nutrients and beneficial things into the cell while keeping unwanted things out

the nucleus has the DNA of the cell: it’s surrounded by a nuclear envelope which keeps the nucleus from the rest of the cell (the nuclear envelope has nuclear pores for movement) DNA serves as a genetic blueprint during cell replication and directs protein synthesis for structural and enzymatic proteins in the cell, so it can serve as a control center for the cell

there are three types of RNA that play roles in protein synthesis: mRNA (messenger RNA) which delivers the DNA genetic code for needed proteins to the ribosomes, which then read the genetic code and make it into the appropriate amino acid sequence for the protein being synthesized. rRNA (ribosomal RNA) is an essential component of ribosomes and tRNA (transfer RNA) transfers the amino acids to their designated site in the protein under construction in the ribosome

gene expression refers to the multi-step process by which information included in a gene is used to direct the synthesis of a protein molecule

in addition to this, micro RNA (miRNA) and small interfering RNA (siRNA) can bind to mRNA and block the synthesis of the protein in a process called RNA interference (RNAi). defects in RNAi have been linked to a variety of diseases, including cancer

human genome= all genetic information coded in a specific set of DNA in a body cell

proteome= all proteins that can be expressed by the protein-coding genes in the genome (they all carry the same genes but because of different regulatory factors will not all synthesize the same proteins)

epigenetics= modification in a gene’s expression that does not involve modification of the gene itself

lipidome= all lipids in the body cells, governed by enzymes under gene control

the cytoplasm is the portion of the cell’s interior not occupied by the nucleus,which consists of various organelles, the cytoskeleton, and the cytosol

organelles are distinct, highly specialized structures that perform various functions within the cell- of these, there are membranous organelles and nonmembranous organelles- membranous organelles are separate compartments in cells enclosed by a membrane similar to the plasma membrane- there are five types that nearly all cells contain: the endoplasmic reticulum (ER), golgi complex, lysosomes, peroxisomes, and mitochondria

nonmembranous organelles have no membrane and are things like ribosomes, proteases, vaults, and centrioles

the cytoskeleton is an interconnected system of protein fibers and tubes that extend through the cytosol (cell liquid- different from ICF because icf includes the fluid inside the organelles)- giving it its shape

the rough ER is stacks of relatively flattened interconnected sacs, while the smooth ER is a meshwork of tiny interconnected tubules- they’re connected to each other, so they’re one organ

the rough er synthesizes proteins for secretion and membrane construction- the outer bit of it is studded with particles that give it a rough appearance (ribosomes, where the protein synthesis takes place)

ribosomes are nonmembranous organelles which carry out protein synthesis by translating mRNA into chains of amino acids  in the sequence dictated by the original DNA code: they bring together all things participating in the protein synthesis- mRNA, tRNA, and amino acids, and provide the enzymes and energy required for linking the protein together (what protein is being made depends on the mRNA)

a finished ribosome is about 20 nm in diameter and made up of two parts of unequal size: a large and a small ribosomal subunit- each is made up of rRNA and ribosomal proteins- when they come together, they form a groove where mRNA passes through to be  translated

unlike the ribosomes in the rough ER, the free-floating ones synthesize proteins that are meant to be in the cytosol- the proteins made by the ones in the rough ER are usually either meant for synthesis of new membrane/other cell components or export out of the cell, and this is a way to differentiate what goes where

about 1/3 of the proteome is usually synthesized in the rough ER

proteins pass through the smooth ER to get to where they need to go

the smooth ER packages new proteins in transport vesicles: it has no ribosomes, but it does have designated exit sites where the proteins balloon outwards and then are pinched off into transport vesicles

it buds off through coat protein 2 (COPII) from the cytosol binding with specific proteins facing the outer surface of the smooth ER membrane at the exit site: these proteins form a ‘coat’ which causes the surface membrane at the site to curve outwards to form a dome-shaped bud around the products- the membrane eventually closes and pinches off to form a transport vesicle

some specialized cells have even more of a smooth ER: if the smooth ER has a lot of cells that specialize in lipid metabolism (for example, secreting lipid-derived steroid hormones) that cell will have an extra compartment for enzymes that help with synthesis of lipids to keep pace with the extra demand

in liver cells, the smooth ER has enzymes specifically for breaking down toxins from things that have gotten into the body or harmful substances produced in the body by metabolism

muscle cells have a modified smooth ER known as the sarcoplasmic reticulum, which stores calcium used in the process of muscle contraction

misfolded proteins are destroyed in the ubiquitin/proteasome pathway

misfolded proteins are tagged with ubiquitin which redirects them to the proteasome which will break them down instead of shipping them out

the proteasome has a hollow core particle with a regulatory particle at each end- the regulatory particles recognize the ubiquitin tag, feed them into the core which breaks the protein down into small chains of amino acids called peptides, those peptides are then broken down further into amino acids by cytosolic enzymes: the amino acids are either recycled or used for energy, the ubiquitin is recycled

ubiquitin also labels other proteins other than misfolded ones (damaged/unneeded) for breakdown in the proteasome

the golgi complex is a membranous organelle closely associated with the ER: it is a stack of flattened, slightly curved, membrane-enclosed sacs- they don’t come into physical contact with each other, though (the number of golgi complexes varies depending on cell type- some may just have one, some cells specialized for protein secretion may have hundreds)

the transport vesicles from the smooth ER go to the golgi complex for further processing- when they reach the golgi complex ( golgi stack), they fuse with the membrane of the sac closest to the center of the cell: the vesicle membrane opens up and becomes integrated into the golgi membrane, and the contents of the interior are released to the inside of the sac- it then travels from the layer closest to the ER to the sac nearest the plasma membrane through action of membrane-curving coat protein I (COPI)  during this transit, two important, interrelated functions take place: the raw proteins are modified to their final forms, and they are sent to the areas they need to go: the proteins are sent to the areas they need to go because their vesicles have unique surface proteins that serve as docking markers- they can only unload their proteins at areas with the appropriate docking marker acceptors

secretory cells have secretory vesicles, which upon stimulus will move to the cell membrane and empty their contents outside: exocytosis is when a vesicle fuses with the plasma membrane and dumps its contents outside, while endocytosis is when the plasma membrane engulfs something and turns it into a vesicle

secretory vesicles only fuse with the plasma membrane and not with any outer membranes so their contents will not be discharged into organelles: this is how it works- the proteins being packaged have a unique sequence of amino acids on one end called a sorting signal- the interior of the plasma membrane contains recognition markers, which are proteins that recognize and attract specific sorting signals. the right protein sorting signal with the right complimentary membrane marker means that the right protein will be packaged: after that, coat proteins called coatomer will bind with another specific protein on the outer surface of the golgi membrane and cause a bud to form around the captured cargo: after budding off, the vesicle sheds its coat proteins and exposes its docking markers, called v-snares, which face outward- they can link with their matching marker (called a t-snare) on the plasma membrane, and then fuse with it to release their contents

lysosomes are small organs that digest extracellular material brought into the cell by phagocytosis- on average, there are usually around 300 in a cell

they are formed in the golgi complex, and contain about 40 powerful hydrolytic enzymes that are synthesized in the ER and then transferred to the golgi complex to be put in the budding lysosome: these enzymes catalyze hydrolysis (splitting with water) which are reactions that break down organic molecules by the addition of water at a bond site (most of these organic molecules are extracellular- ubiquitin breaks down the intracellular ones)

endocytosis can happen in three ways: phagocytosis, pinocytosis, and receptor-mediated endocytosis depending on the contents of the ingested material

in pinocytosis, a droplet of ECF is taken up nonselectively: it traps the extracellular fluid nonselectively in a vesicle (endocytic vesicle or endosome) this can also be a way to retrieve extra plasma membrane that has been added to the cell during exocytosis

in receptor-mediated endocytosis, a specific target molecule like a protein binds to a receptor specific to that molecule, causing the membrane to pocket inward and then seal it off in a vesicle- clathrin molecules are the coat proteins that pocket inwards, and the resulting vesicle is called a coated pit because it is coated with clathrin- b12, cholesterol complexes, iron, and insulin are things selectively taken into cells via receptor-mediated endocytosis- unfortunately, viruses like flu viruses and HIV can also get into cells via receptor-mediated endocytosis by binding with membrane receptors usually used to internalize a needed molecule

in phagocytosis, large particles are internalized- only a few cells can do this, such as macrophages- they do this by extending appendages known as pseudopods (false feet) and trapping the particle in an internalized vesicle known as a phagosome- then a lysosome fuses with the phagosome, and releases hydrolytic enzymes into the phagosome that break down the particle without harming the cell into raw ingredients like fatty acids, amino acids, and glucose- which the cell can then use

lysosomes remove worn-out organelles- they break them down into raw ingredients that can be reused in a process known as autophagy- if a cell is starving, it may do this to healthy cellular components in order to get more energy and live longer- some people cannot synthesize some of the lysosomal enzymes, which leads to accumulation within the lysosomes of the compound that’s usually digested by that enzyme- these often lead to lysosomal storage diseases, which vary in severity depending on what enzyme is missing- tay-sachs disease is an example of this which involves accumulation of complex molecules in nerve cells and profound nervous system degeneration as a result

peroxisomes are membranous organelles that produce and decompose hydrogen peroxide in the process of degrading potentially toxic molecules: there are several hundred of them in one cell. they are like lysosomes, which also house enzymes, but unlike lysosomes, which contain hydrolytic enzymes, peroxisomes contain oxidative enzymes and catalase: oxidative enzymes use oxygen (O2) to strip hydrogen from various organic molecules: this reaction helps detoxify wastes produced in the cell and foreign toxic compounds that have entered the cell,  like alcohol consumed in beverages: the major product generated is hydrogen peroxide, h2o2, which is formed by molecular oxygen and the hydrogen atoms stripped from the toxic molecule- h2o2 is potentially destructive if allowed to accumulate or escape from the contents of the peroxisome- however, the peroxisomes also contain catalase which splits it back into h2o and o2, so it doesn’t escape into the cell 

 mitochondria is the powerhouse of the cell, and are enclosed by two membranes: they’re descendants of bacteria that were engulfed and eventually became organelles, and possess their own DNA different from the one in the cell’s nucleus called mitochondrial DNA (mtDNA), which contains the genetic codes for producing many of the molecules the mitochondria need to generate energy. mitochondrial diseases affect about 1 in 4000 people, mainly children, and have no cure

each mitochondrion, a membranous organelle, is enclosed by a double membrane- a smooth outer membrane that encloses the mitochondrion, and an inner membrane that forms a series of enfoldings or shelves called cristae: these project into an inner cavity with gel-like solution known as the matrix. these two membranes are separated by a narrow intermembrane space- the cristae contain proteins that ultimately use o2 to convert the energy in food into a usable form (there’s so many extra folds for extra surface area) 

mitochondria are sometimes connected in a network called the mitochondrial reticulum- they play a major role in generating atp (adenosine triphosphate) for energy- to get energy, they split a phosphate bond in atp to give ADP (adenosine diphosphate) + phosphate (P) + energy- 

cellular respiration is how energy-rich molecules are broken down to form ATP, using O2 and generating CO2 in the process - in most cells, this is done by glycolysis in the cytosol, the citric acid cycle in the mitochondrial matrix, and oxidative phosphorylation at the mitochondrial inner membrane 

glycolysis breaks down a six-carbon sugar into two three-carbon pyruvate molecules: during this, two hydrogens are released and transferred to two NADH molecules for later use: some energy from the broken chemical bonds of glucose is used to convert ADP to ATP, but this only yields two molecules of ATP, so it is not efficient- the pyruvate produced by glycolysis in the cytosol is transferred into the mitochondrial matrix, where one of its carbons is removed in the form of CO2, and another hydrogen is removed and transferred to another NADH: the two carbon molecule (an acetyl group) remaining after this combines with coenzyme a (CoA) to make acetyl CoA which then enters the citric acid cycle (also known as the Krebs cycle) Acetyl CoA, which has two carbons, then fuses with oxaloacetate, which has four carbons, to form a six-carbon citrate molecule (at intracellular pH, citric acid exists in its ionized form citrate) 

two carbons are kicked off the citrate after that, turning it back into four carbon oxaloacetate- which can then fuse with another acetyl CoA to do this again- the CoA is also released so it can fuse with another acetyl group and make another molecule of acetyl CoA - the carbons kicked off are transformed into CO2 and released as waste- 

then they