#Microstructure

[materialsscienceandengineering]

Researchers investigate microstructure evolution of oxide films of Fe-Cr–based alloys

Ferritic/martensitic steels and austenitic steels are the primary candidate materials for advanced nuclear energy systems. The corrosion resistance of the materials is one of the factors that ensures the safe service of key components. Since the corrosion resistance of materials is highly related to the characteristics of the formed oxide films, it is crucial to investigate the oxide films of candidate materials in high-temperature water. Researchers at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) selected candidate materials (15-15Ti, 316L and T91) to study their early oxidation behavior in high-temperature steam and the evolution process of the oxide microstructure. The results were published in Journal of Materials Science & Technology. The Ni-rich layer in the oxide film of austenitic steels (15-15Ti, 316L) is composed of Fe-Cr spinel oxide and Ni-rich phase. Researchers at IMP found a large number of nanopores in the inner oxide layer that could serve as a rapid gas transport channel for oxidant. They revealed the evolution process of Ni-rich layer and the formation mechanism of nanopores in the inner oxide layer.

Read more.

[horizontitanium]

The properties of metals are determined by their metallurgy, and for applications such as medical use, these properties must be optimized. To achieve this, international standards specify the required microstructure. Two key standards for medical titanium materials are ASTM F136 and ISO 5832-3.

ISO 5832-3 defines microstructure classes with specific alpha and beta morphologies and phase distributions, detailed through micrographs. In contrast, ASTM F136 outlines microstructure requirements without specifying exact classes or providing micrographs, thus omitting precise details on alpha and beta phase distributions.

To illustrate this, consider the example of the color blue. ASTM F136 broadly accepts any shade of blue for medical applications. However, ISO 5832-3 specifies exact color codes, categorizing shades from Class Sr. No. A1 to A9, and thus sets rigorous microstructure requirements for medical grades. ASTM F136 lacks this level of detail and does not categorize shades of blue, merely stating that any blue is acceptable for medical use.

Therefore, adhering to the ISO 5832-3 standard is crucial for ensuring the precise microstructure requirements in Titanium materials needed for medical device manufacturing.

To know more about the importance of microstructure in titanium materials for medical applications, write us at info@horizontitanium.com

[civilchhapola]

The Structure of a Tree: Understanding the Macrostructure and Microstructure of Timber

Trees have been an important resource for human civilizations for thousands of years, providing building materials, fuel, and other essential products. In civil engineering, timber is one of the most commonly used materials, thanks to its strength, durability, and versatility. Understanding the structure of trees is therefore crucial for civil engineers who work with timber. Structure of a…

[tumblermixer]

Microstructures

Stainless steel has larger grains compared to cast iron as seen in the figures. The formation of such grains results in a lower tensile strength. Therefore, stainless steel is more ductile than cast iron. As a result, the tank can absorb a certain amount of shock from the repeated colliding of the mixture upon the rotation of the tumbler mixer without fracturing.

[psalmsofpsychosis]

@maderilien you... broke me.....

[sukimas]

admittedly i could have a confluence of other mental weirdness that explains the developmental weirdness, social weirdness, sensory weirdness, and odd interests, but i'm a proponent of the duck theory of neurodivergence. if it looks like a duck, swims like a duck, and quacks like a duck, it's probably a duck.

[brutulist]

la fin is located in an abandoned cathedral, and i think about all the ways nature creeps in, how it ultimately takes over something that was man-made, and how that connects to the vampires that inhabit its halls, how nature has found a way to creep into their humanness and reclaim the body as its own; yes, vampires are abnormal from a human perspective, but to nature? aren't they part of the cycle?

[metnmat]

Metal Manufacturing as the Smart Specialization of the Regions

Metal manufacturing has emerged as a shining beacon of innovation and economic progress, transforming from a conventional heavy industry into a smart specialization that drives regional development. This article aims to shed light on the intricate world of metal manufacturing, encompassing its evolution, significance, technological advancements, and its pivotal role as a smart specialization strategy across diverse regions.

METNMAT RESEARCH AND INNOVATION

1. Introduction: From Tradition to Transformation

At the heart of industrial evolution lies the remarkable journey of metal manufacturing. Once associated with the imagery of smoke-filled factories and manual labor, this sector has undergone a revolutionary metamorphosis. Today, it stands tall as a vanguard of innovation, steering the course of regional development toward new horizons. The transition from tradition to transformation is a testament to the resilience and adaptability of metal manufacturing in the face of changing times.

2. The Significance of Metal Manufacturing

Metal manufacturing occupies a pivotal position in the tapestry of industries that shape the modern world. From the towering structures of urban landscapes to the intricate components within electronic devices, its significance is omnipresent. The products of metal manufacturing serve as the backbone of diverse sectors, breathing life into everything from automobiles to advanced medical equipment. This significance underscores its role not only as an economic driver but also as an enabler of technological progress and societal advancement.

"From forges of tradition to the frontier of technology, metal manufacturing stands as a beacon of progress." - [METNMAT RESEARCH AND INNOVATION]

3. Evolution of Metal Manufacturing Techniques

The annals of metal manufacturing are adorned with a story of relentless innovation and technological prowess. The evolution of techniques from labor-intensive processes to precision-driven methodologies is a captivating journey that mirrors humanity's quest for perfection. Gone are the days of hammer and anvil as digital fabrication technologies have taken center stage. The marriage of computer-aided design (CAD) and computer-aided manufacturing (CAM) has birthed a new era of digital craftsmanship, where intricate designs come to life with unparalleled accuracy and speed.

4. Technological Advancements Driving Smart Metal Manufacturing

The dawn of the fourth industrial revolution has cast a transformative spell on the realm of manufacturing. Metal manufacturing, in particular, has been a willing participant in this digital renaissance. The infusion of sensors, Internet of Things (IoT) devices, and data analytics has given rise to a new era of smart metal manufacturing. This paradigm shift empowers manufacturers with real-time insights, predictive maintenance capabilities, and the ability to fine-tune processes for optimal efficiency. The convergence of technology and metallurgy has bestowed upon us a realm where precision meets intelligence, and where waste is minimized through data-driven decision-making.

5. The Role of Skilled Workforce in Metal Manufacturing

While technology orchestrates the symphony of modern metal manufacturing, it is the skilled workforce that wields the baton. Behind the curtain of automation and innovation, there exists a cohort of talented individuals whose expertise ensures the seamless orchestration of complex processes. Engineers, technicians, and designers collaborate harmoniously to breathe life into raw materials, sculpting them into works of art that power our modern world. The symphony of metal manufacturing requires not only the instruments of technology but also the virtuosity of skilled human hands.

6. Sustainable Practices in Metal Manufacturing

Amidst the backdrop of escalating environmental concerns, the concept of sustainability has permeated virtually every facet of human endeavor. Metal manufacturing, with its historical reputation for resource-intensive processes, has not been impervious to this shift. However, the sector has responded with remarkable ingenuity, embracing sustainable practices that echo a commitment to both innovation and environmental stewardship.

The adoption of sustainable practices in metal manufacturing spans various dimensions. One notable avenue is the recycling of scrap metal. In an era where responsible resource utilization is paramount, the recycling of scrap metal not only conserves precious resources but also curtails the environmental impact of mining and extraction. The metamorphosis of discarded metal into raw material breathes new life into the production cycle, reducing energy consumption and minimizing waste.

Moreover, energy efficiency has become a cornerstone of sustainable metal manufacturing. From the optimization of heating and cooling systems to the deployment of energy-efficient technologies, manufacturers are meticulously recalibrating their processes to minimize energy consumption. This not only translates into cost savings but also contributes to a greener and more environmentally conscious industry.

7. Regional Smart Specialization: Boosting Economic Growth

In an era characterized by unprecedented globalization and interconnectedness, regions seek strategies that can catapult them onto the global stage. Enter the concept of smart specialization. This strategic approach involves concentrating resources and efforts on areas of expertise, thereby fostering economic growth and innovation. Metal manufacturing emerges as an alluring candidate for smart specialization, harnessing its multifaceted applications and demanding technological landscape.

The synergy between regional strengths and metal manufacturing is a symbiotic relationship that begets economic prosperity. By aligning a region's existing industrial prowess with the demands of metal manufacturing, a unique competitive advantage is forged. This advantage, coupled with strategic investments in research, development, and education, positions regions as formidable players in the global market. The allure of specialized metal products, coupled with a technologically adept workforce, becomes a potent recipe for attracting investment, generating employment, and fueling economic expansion.

8. Case Studies: Successful Implementation of Metal Manufacturing Specialization

The theoretical underpinnings of smart specialization find tangible expression in real-world case studies. Several regions have harnessed the potential of metal manufacturing specialization, leading to transformative outcomes. One such compelling example is the resurrection of a declining industrial town through the establishment of a cutting-edge metal research and production hub.

This case study highlights the transformative power of deliberate specialization. By identifying and capitalizing on latent potential, this region was able to transition from the throes of economic decline to becoming a thriving center of innovation. The infusion of research institutions, collaboration between academia and industry, and the cultivation of a skilled workforce converged to breathe new life into the region. The success story underscores the significance of strategic metal manufacturing specialization in rejuvenating stagnant economies and fostering resilience.

In the upcoming segments of this article, we will delve into the challenges that underlie the path to metal manufacturing specialization, gaze into the crystal ball to discern future prospects, and ultimately, draw our conclusions from the symphony of insights presented.

9. Challenges and Future Prospects

While the journey of metal manufacturing as a smart specialization is marked by resounding successes, it is not without its share of challenges. These challenges, however, are not roadblocks but rather stepping stones that beckon the industry toward an even brighter future.

Challenge 1: Global Competition and Innovation In a world characterized by seamless connectivity, metal manufacturing faces the challenge of global competition. As regions vie to establish themselves as hubs of specialization, the competition intensifies. To remain at the vanguard, continuous innovation becomes imperative. The industry must relentlessly push the boundaries of technology, embracing novel processes, materials, and design paradigms. Innovation not only sustains competitiveness but also kindles the spark of differentiation that sets pioneers apart.

Challenge 2: Skilled Workforce Development The symbiotic relationship between technology and skilled human capital is pivotal in the realm of metal manufacturing. However, nurturing and maintaining a skilled workforce is a multifaceted challenge. The industry must bridge the gap between academia and industry, ensuring that educational curricula align with the demands of modern metal manufacturing. Furthermore, the allure of other sectors and the aging workforce pose recruitment challenges. A concerted effort toward attracting and retaining talent is imperative to keep the wheels of specialization turning.

Challenge 3: Sustainability Imperatives While sustainable practices have found a home in metal manufacturing, the journey toward comprehensive environmental stewardship is ongoing. Striking a balance between resource utilization, energy efficiency, and waste reduction remains a complex endeavor. Technological innovations will play a pivotal role in overcoming these challenges, enabling the industry to ascend to new heights of sustainable production.

Challenge 4: Regulatory Landscape The metal manufacturing sector operates within a regulatory framework that demands compliance with environmental standards, safety protocols, and labor regulations. Navigating this intricate landscape can be arduous, particularly for smaller enterprises. Adaptation to evolving regulations and the proactive embrace of compliance becomes paramount to ensure the industry's sustained growth.

Future Prospects: A Vision of Promise The path ahead for metal manufacturing as a smart specialization is imbued with promise and potential. As technology continues to advance, the industry stands on the precipice of transformative breakthroughs. Additive manufacturing, nanotechnology, and advanced materials hold the keys to unlocking new frontiers of possibility. The fusion of these innovations with sustainable practices not only bolsters the industry's competitive edge but also paves the way for a more environmentally conscious and socially responsible future.

Conclusion

In conclusion, metal manufacturing has evolved into a smart specialization strategy that propels regions toward economic prosperity. Its fusion of traditional craftsmanship with cutting-edge technology exemplifies human ingenuity at its finest.

"In the crucible of smart specialization, metal manufacturing reshapes regions into hubs of innovation." - [METNMAT RESEARCH AND INNOVATION]

FAQs

What is smart specialization in the context of metal manufacturing? Smart specialization in metal manufacturing refers to the strategic focus on this sector to drive regional economic growth and innovation.

How does technology contribute to sustainable metal manufacturing? Technology enables energy-efficient processes, waste reduction, and the use of eco-friendly materials in metal manufacturing.

What role does a skilled workforce play in metal manufacturing? A skilled workforce is essential for operating advanced machinery, designing innovative products, and driving continuous improvement.

Can regions with limited metal resources benefit from metal manufacturing specialization? Yes, regions can leverage technology, innovation, and collaboration to overcome resource limitations and create a successful metal manufacturing specialization.

What does the future hold for metal manufacturing as a smart specialization? The future looks promising as technology advances, enabling more efficient, sustainable, and globally competitive metal manufacturing practices.

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[fanservices123]

[materialsscienceandengineering]

Unraveling the fundamental principles of eutectic solidification with real-time, nanoscale imaging

During eutectic solidification, a mixture of two or more solids self-assemble, forming composite microstructures ranging from ordered layers to intricate maze-like patterns that underlie properties like tensile strength or ductility. Up to this point, researchers have not understood what conditions drive eutectics to form certain patterns, which is critical for designing reproducible next-generation eutectic composites. Capturing real-time solidification of an aluminum-nickel eutectic alloy (Al-Al3Ni) in nanometer resolution revealed that increasing the solidification velocity shifts microstructure from irregular and faceted to regular and rounded, according to a study led by University of Michigan researchers recently published in Acta Materialia.

Read more.

[horizontitanium]

Metal implants play a crucial role in biomedical engineering, offering durability and reliability for bone reconstruction.

With superior mechanical properties compared to ceramics and polymers, metals like Titanium Ti-6Al-4V (Gr.5) ELI are preferred for handling heavy loads. In fact, 80% of implants are made from metal, with Titanium Ti-6Al-4V (Gr.5) ELI being the major choice, especially due to its higher fatigue strength and fracture toughness.

The value of the Elastic Modulus / Young's Modulus, should closely match that of the bone to minimize the stress-shielding effect between the bone and the implant. We will delve into more details about the stress-shielding effect in our next post.

Ti-6Al-4V ELI closely matches bone's Young's modulus as compared to other metallic implantable materials, making it a top choice for bone replacements.

For more information, contact us at info@horizontitanium.com

[mindblowingscience]

The constant ebb and flow of hormones that guide the menstrual cycle don't just affect reproductive anatomy. They also reshape the brain, and a new study has given us insight into how this happens. Led by neuroscientists Elizabeth Rizor and Viktoriya Babenko of the University of California Santa Barbara, a team of researchers tracked 30 women who menstruate over their cycles, documenting in detail the structural changes that take place in the brain as hormonal profiles fluctuate. The results, which are yet to be peer-reviewed but can be found on preprint server bioRxiv, suggest that structural changes in the brain during menstruation may not be limited to those regions associated with the menstrual cycle. "These results are the first to report simultaneous brain-wide changes in human white matter microstructure and cortical thickness coinciding with menstrual cycle-driven hormone rhythms," the researchers write.

Continue Reading.

[artechoceneexplorer]

ODDYSEUS_MISSION_AE#1744

Sample obtained from the Odysseus mission, sent to gather information about the planet Kepler-138d, a super-earth water world characteristic for its dense, water saturated atmosphere, and whose clouds occasionally appear green.

The mystery of these green clouds has finally been resolved with this analysis of samples that were collected from one of these green clouds as the rover descended into the atmosphere, 15km up in the clouds.

A diverse community of cyanobacteria-like phototrophic microbes (described as Ambrosiasphaera sp.) seems to be responsible for the unusual color of the clouds. These microbes, alongside the many others in the floating ecosystem they help support, seem to have developed hydrogen filled membranous organelles to float over the dense atmosphere. They also seem to have developed a cell wall with an unusual microstructure, extremely water absorbing to take advantage of floating droplets of water.

Some species seem to have developed predatory lifestyles, feeding on the plentiful Ambrosiasphaera chains, here seen one of these lifestyles, here seen one with one of the most unusual ways observed to catch and consume prey (described as Flagellovenator sp.). It floats passively with its flagellum extended, until it comes into contact with something. The appendix is covered in hairs not unlike those on the feet of Gekkonids, able to stick without any sticky substance needed. Once captured, it's bivalves cell wall opens and an amoeboid body penetrates the cell wall and starts digesting it's prey.

[a-dinosaur-a-day]

Round Three: Ambopteryx vs Caihong

Ambopteryx longibrachium

Artwork by Gabriel Ugueto, written by @i-draws-dinosaurs

Name meaning: Both wings with long arms

Time: 163 million years ago (Callovian stage of the Middle Jurassic)

Location: Haifanggou Formation, China

Look, evolution has done a lot of weird stuff to dinosaurs. It put penguins underwater, and did whatever the hall mamenchisaurid necks are, and game lambeosaurs a built-in face trumpet. But I would argue there is one group that represents dinosaur evolution at its most unhinged, and that is scansoropterygidae.

Scansoriopterygids were generally considered “weird little tree dinosaurs” in the 2000s, with long fingers to pick grubs out of bark or something. Then Yi qi swept along in 2015 and revealed that those long fingers were actually supporting membranous bat wings. With an extra bony rod (the “styliform element”) sticking out of the wrist to help support it, because well if you’re a dinosaur evolving bat wings why bother being normal about it after that? Although really, the dinosaurs did it first so bats actually have dinosaur wings.

Yi was sensational, but it was also extremely weird and completely unique. Even other scansoriopterygids didn’t have wing membranes, so the whole bat thing was a bit up in the air. Or not up in the air, as the case may be. But then along comes Ambopteryx, published in 2019, packing another set of skin wings, and the vindication of Yi is complete! 

Ambopteryx preserves a styliform element and wing membrane, as well as a thick coat of feathers, and honestly out of a whole selection of dinosaurs I think these might be some of the most huggable in the lot. Obviously this whole wing membrane thing didn’t end up working out for them long term, but Ambopteryx is part of an incredible lineage that challenged what we thought was possible for dinosaurs!

Caihong juji

Artwork by @i-draws-dinosaurs, written by @i-draws-dinosaurs

Name meaning: Rainbow with big crest

Time: 161 million years old (Oxfordian stage of the Late Jurassic)

Location: Tiaojishan Formation, China

It’s always a special treat to hear the announcement of a dinosaur with known colours, because it gives the most direct impression of how truly stunning these animals would have been to witness in real life. And Caihong might just be the most spectacular of them all so far, described in 2018 from an immaculate full-body fossil that preserves detailed feathers! Caihong’s feathers are longer than some other floofy dinosaurs, and would have had the appearance of a luxurious mane along its neck. Not only that, the fossil preserves feather microstructures that in life would have made this dinosaur gloriously iridescent!

Now iridescent dinosaurs aren’t new, Microraptor has been decked out in fabulous starling-esque plumage for a while now, but Caihong absolutely takes it to the next level. Its whole body was covered in iridescent black, including the enormous tail, but the real star of the show are the platelet-like melanosomes found on the head, neck, and the base of the tail. Different from the usual iridescent melanosomes, the structure of these tiny organelles reflects brilliantly iridescent colours, like those on the heads of hummingbirds and particularly the bright purple feathers on the necks of the trumpeter family. Caihong would have put on an absolutely dazzling jewel-toned display in the treetops or on the forest floor of prehistoric China!

[evidence-based-activism]

do you believe that men and women have inherent differences in their brain structure at birth and throughout life? and this does not imply superiority of one over another, merely differences in structure leading to different tendencies along a statistical distribution by gender. for instance women tend to have larger corpus collosums meaning better communication between hemispheres and emotional integration, while men tend to have higher visuospatial abilities which is explanatory for more men in fields like mechanical engineering. exceptions to the rule are the rule, so women can be aeronautical engineers and men can be heartfelt poets. The idea though is that we are born with natural tendencies.

on the individual level forgetting about gender momentarily, certain people are born with natural inclinations towards verbal or mathematical abilities that are notable in early childhood

i understand the top down society and roles change your brain idea which is absolutely true, so there is energy for change in the idea of abolishing gender roles, but do you disagree that there is any bottom up force? especially with (generally) a chromosome of difference between sexes?

Hi Anon!

Sex Differences in Adult Brains

This 2022 review [1] examines two large scale studies from 2021 [2-3]. These two studies both examined sex differences in the human brain, but came to different conclusions. The first [2] directly examined a large sample of brain scans and found small sex differences in many brain areas. In contrast, the second [3] performed a meta-synthesis of three decades of research "emphasizing meta-analyses and other large studies" and found sex differences in the brain are explained by differences in overall body size.

The review [1] I mentioned takes the stance that "differences in the mean value of largely overlapping distributions, and they show small-to-moderate effect sizes; however, we do not understand their microstructural basis, the causal factors shaping them, or if they facilitate sex differences or equivalences in behavior and cognition", essentially agreeing with the direct brain analysis [2] (but emphasizing the limitations of this finding) and suggesting that meta-analyses and reviews like [3] fail to find differences due to methodological heterogeneity.

In response to this, the authors of [3] released a response [4] in 2024 pointing out that while large scale studies do often find significant (but small) sex differences in the brain, they do not find consistent differences (i.e., one study may find brain area A is larger in males while another finds the same area is larger in females). In addition they note that large sample sizes inevitably "detect statistically significant interactions,including sex differences, of clinically trivial and meaningless magnitude” [emphasis mine].

Personally, I'm not sure if the distinction between "no sex differences once corrected for body size" vs "very small sex differences once corrected for body size" is really all that important. In either case, differences within each sex are larger than differences between each sex, suggesting that it is some other factor underlying the differences (if they do indeed exist).

Sex Differences in Children's Brains

In addition to the above, simply finding small sex differences also wouldn't tell us the cause of these differences. The above studies were based on adults, and – as you've acknowledged – there's a significant difference between how we treat female and male people in society. Given the brain's highly plastic (changeable, adaptable) nature, it's probable that observed differences could be the result of this socialization.

The idea, then, is to look for sex differences in very young children, who have not been exposed to such gendered socialization yet. For example, this study [5] suggests there are small differences in regional brain volumes at birth and this study [6] claims to find small sex differences in fetal brain connectivity.

However, the conclusion that these results support biological differences between the sexes relies on the assumption that there are no differences in socialization at these stages. Other work [7] suggests that this is not a fair assumption, showing that "women who learn the sex of their fetus before birth are engaging in gendered verbal interactions throughout pregnancy." Given that we know children's language [8] and social [9] development begin in the womb, this difference in treatment suggests that gendered socialization can also begin in the womb.

If Sex Differences Do Exist, Do They Matter?

Beyond this, there appears to be a general assumption that if small sex differences are found they are also relevant. However, there's no current consensus on how or why any proposed brain sex differences would produce observed sex differences in mental disorders or behaviors [3, 4].

This is important because it's not so much the existence of a difference than the relevance of a difference that interests people. What does it matter whether there's a sex difference in a brain region's volume if it isn't related to sex differences in behavior? We're concerned with sex differences in the body (e.g., sex differences in lung size) because they have an impact on some relevant factor in people's lives (e.g., equity in sports, differences in lung disease [10]); the same is true of our interest in the brain, so the fact that we don't see reliable sex-driven connections between brains and behavior suggests that any differences may not be of particular interest.

Sexual Dimorphism in the Body

And there are sex differences in the body. In fact, the article [4] points out that the one reliable sex difference in brains (overall volume difference) is smaller than similar size differences in other organs.

This article [11] discuss the underlying factors (genetics and hormones) for human sex differences. For a single system's example, this review [12] discusses "sex-influenced immune responses" and what specific relevance they have to understanding and treating human disease. The book Invisible Women [13] discuss many more sex differences, how much of society ignores these differences, and the negative effects this has on women.

All of this is to say that I actually wouldn't have been surprised to see sex differences in the human brain. (Although I would still point out the tenuous connections between brain and behavior.) That being said, current research suggests that sex is not a reliable determinant of brain anatomy or physiology.

Individual Predispositions

To address your question of predisposition: It is likely that individual predispositions (i.e., genetic predispositions) play a role in some behaviors and cognition (the nature part of nature and nurture).

However, current evidence indicates that these predisposition are unlikely to be linked to sex.

I hope this helps you! Let me know if you have follow up questions!

References below the cut:

DeCasien, A. R., Guma, E., Liu, S., & Raznahan, A. (2022). Sex differences in the human brain: a roadmap for more careful analysis and interpretation of a biological reality. Biology of Sex Differences, 13(1), 43.

Williams, C. M., Peyre, H., Toro, R., & Ramus, F. (2021). Neuroanatomical norms in the UK Biobank: The impact of allometric scaling, sex, and age. Human Brain Mapping, 42(14), 4623-4642.

Eliot, L., Ahmed, A., Khan, H., & Patel, J. (2021). Dump the “dimorphism”: Comprehensive synthesis of human brain studies reveals few male-female differences beyond size. Neuroscience & Biobehavioral Reviews, 125, 667-697.

Eliot, L. (2024). Remembering the null hypothesis when searching for brain sex differences. Biology of sex Differences, 15(1), 14.

Khan, Y. T., Tsompanidis, A., Radecki, M. A., Dorfschmidt, L., APEX Consortium, Austin, T., ... & Baron-Cohen, S. (2024). Sex Differences in Human Brain Structure at Birth. bioRxiv, 2024-06.

Wheelock, M. D., Hect, J. L., Hernandez-Andrade, E., Hassan, S. S., Romero, R., Eggebrecht, A. T., & Thomason, M. E. (2019). Sex differences in functional connectivity during fetal brain development. Developmental cognitive neuroscience, 36, 100632.

Barnes, M. W. (2015). Anticipatory socialization of pregnant women: Learning fetal sex and gendered interactions. Sociological perspectives, 58(2), 187-203.

Gervain, J. (2018). The role of prenatal experience in language development. Current opinion in behavioral sciences, 21, 62-67.

Castiello, U., Becchio, C., Zoia, S., Nelini, C., Sartori, L., Blason, L., ... & Gallese, V. (2010). Wired to be social: the ontogeny of human interaction. PloS one, 5(10), e13199.

Carey, M. A., Card, J. W., Voltz, J. W., Arbes Jr, S. J., Germolec, D. R., Korach, K. S., & Zeldin, D. C. (2007). It's all about sex: male-female differences in lung development and disease. Trends in endocrinology and metabolism: TEM, 18(8), 308.

Federman, D. D. (2006). The biology of human sex differences. New England Journal of Medicine, 354(14), 1507-1514.

Wilkinson, N. M., Chen, H. C., Lechner, M. G., & Su, M. A. (2022). Sex differences in immunity. Annual review of immunology, 40(1), 75-94.

Perez, C. C. (2019). Invisible women: Data bias in a world designed for men. Abrams.

[sysboxes]

It's possible for alters to have their own mental health!!! Alters can have personality disorders that other alters don't have, I think what you're talking about is autism, ADHD and other disorders similar! (As those affect the brain and therefore affect the whole system, but personality disorders are a different sort of thing, so one alter can have a PD and the others might not!) We can provide links if you'd like ^^ /nm /info

Hey there Anon! Thank you for the offer. We also received the following anon from (probably) another user, which I'd like to address here as well:

Alters can have personality disorders: (link) “✘ MYTH: ALTERS CAN’T HAVE THEIR OWN MENTAL HEALTH ISSUES IF THE MAIN SURVIVOR DOESN’T HAVE THEM. They actually can, and many do. It’s extremely common for individual alters to battle depression, anxiety, OCD, bipolar, eating disorders, self harm, etc., while other members of the system experience no such thing. Some extremely differentiated systems may even need that system member to come forward and take medications that the rest of the system does not need and will not get. ..and their brain’s neurology responds accordingly. But, make no mistake, most expressions of mental illness amongst alters are incredibly real and valid and should be treated as such.” (cut up a little, the source is above, we're pretty sure the source is reliable, it seems so. We've also had other systems say this too, and to us that's how it works, as only one of us as far as we know are affected by NPD)

Firstly, I feel the paragraph that was cut out of the Beauty After Bruises section is very important for further context and explanation. It's quoted here below:

One note about some disorders, however. Non-verbal, poor eye contact, savant-like, or sensory-processing-disorder alters can be extremely common traits in DID systems. However, it’s important not to just jump to calling these parts “autistic” if the system as a whole is not autistic. It’s possible for alters to behave in ways that mimic their understanding of SYMPTOMS in other disorders they know about, while not actually possessing the neurology for them. This is a complicated subject we could try to elaborate more on at some point, but it’s just an encouragement to pause and not automatically label some parts as having certain conditions just because they show a few traits of them. It can cause a great deal of conflation and misrepresentation of those illnesses. It may also be purely based on discriminatory or uneducated stereotypes of those conditions that were adopted into a young child’s mind. So, it’s just helpful to check for that possibility first!

As Beauty After Bruises is saying here, neurology takes a place in this discussion. It seems as if this resource is mostly stating that alters can all struggle with mental illness, and can appear to struggle singularly with those illnesses symptoms -- in which case, the "This alter is a symptom holder" is exactly the language we feel comfortable with. Until we are able to research more, we're wary about spreading potential misinformation about how brains work.

As mods, we absolutely want to do our best to avoid spreading misinformation. From our understandings, NPD and similar personality disorders are caused by a structural shift in the brain -- something physical and concrete. Here's some of our resources we found on NPD.

Source 1: “They analyzed a total of 34 test subjects, of which 17 suffered from a narcissistic personality disorder… Using magnetic resonance imaging (MRI) methods, the scientists measured the thickness of the patients' cerebral cortex… The findings revealed that those subjects suffering from narcissistic personality disorder exhibited structural abnormalities in precisely that region of the brain, which is involved in the processing and generation of compassion.”

Source 2: “The decreased brain white matter microstructures among three clusters were found in the association, projection/thalamic and connection pathways of white matter in young adult males with NPD. The abnormal white matter brain regions may be one of the neuropathological basis of the pathogenesis of young males with NPD, and it may be related to white matter development in early adulthood."

Based on these sources, the moderators are most comfortable using the language of alters being symptom holders. Both sources indicate that NPD affects the structural nature of the brain, which would impact all of the members of the system. However, like Beauty After Bruises was suggesting, that doesn't mean that various alters don't reflect those symptoms in different ways. It's absolutely possible for alters to struggle more or less with disorders, or even seemingly not at all.

I hope this clarifies our perspectives. Thank you!