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The covid-19 variant JN.1 may have been able to evade antibodies and spread globally due to one critical mutation to its spike protein

A new artificial intelligence model can predict how different proteins may bind to DNA.

Solid-state electrolytes have been explored for decades for use in energy storage systems and in the pursuit of solid-state batteries. These materials are safer alternatives to the traditional liquid electrolyte -- a solution that allows ions to move within the cell -- used in batteries today. However, new concepts are needed to push the performance of current solid polymer electrolytes to be viable for next generation materials.

Physicists have used Doppler-shifted nuclear resonant absorbers to form a nuclear frequency comb, enabling a quantum memory in the notoriously difficult X-ray range.

A research team has constructed an unprecedented chiral-structured interface in perovskite solar cells, which enhances the reliability and power conversion efficiency of this fast-advancing solar technology and accelerates its commercialization.

A research team reports a pioneering plasma-catalytic process for the hydrogenation of CO2 to methanol at room temperature and atmospheric pressure. This breakthrough addresses the limitations of traditional thermal catalysis, which often requires high temperatures and pressures, resulting in low CO2 conversion and methanol yield.

Most of us learned about butterfly metamorphosis as a kid -- a wriggly caterpillar molts its skin to form a tough chrysalis and emerges as a beautiful butterfly. But how exactly do chrysalises stay anchored as the butterfly brews within? Research shows that, despite their silks being weak and thin on their own, caterpillars can expertly spin them into chrysalis support structures resembling hook-and-loop fasteners and multi-strand safety tethers.

Microalgae such as the diatom Odontella aurita and the green alga Tetraselmis striata are especially suitable as 'biofactories' for the production of sustainable materials for 3D laser printing due to their high content in lipids and photoactive pigments. An international research team has succeeded for the first time in manufacturing inks for printing complex biocompatible 3D microstructures from the raw materials extracted from the microalgae.

Researchers invented a technique that uses a specialized light projector and a photosensitive chemical additive to imprint two- and three-dimensional images inside any polymer. The light-based engraving remains in the polymer until heat or light are applied, which erases the image and makes it ready to use again. The technology is intended for any situation where having detailed, precise visual data in a compact and easily customizable format could be critical, such as planning surgeries and developing architectural designs.

Researchers invented a technique that uses a specialized light projector and a photosensitive chemical additive to imprint two- and three-dimensional images inside any polymer. The light-based engraving remains in the polymer until heat or light are applied, which erases the image and makes it ready to use again. The technology is intended for any situation where having detailed, precise visual data in a compact and easily customizable format could be critical, such as planning surgeries and developing architectural designs.

Machine learning is a powerful tool in computational biology, enabling the analysis of a wide range of biomedical data such as genomic sequences and biological imaging. But when researchers use machine learning in computational biology, understanding model behavior remains crucial for uncovering the underlying biological mechanisms in health and disease. Researchers now propose guidelines that outline pitfalls and opportunities for using interpretable machine learning methods to tackle computational biology problems.

In the centre of a distant galaxy, a supermassive black hole has swallowed up a star 9 times the sun’s mass in the biggest and brightest such cosmic meal we’ve ever seen

A zigzag design can maximise how much heat walls radiate into space, while minimising heat absorption from the ground

Both Lin Yu-ting of Taiwan and Imane Khelif of Algeria earned medals in female boxing competition at the 2024 Olympics. This has caused a controversy because both boxers, according to reports, have some form of DSD – difference of sex development. This means they have been caught up in the culture war regarding trans athletes, even though neither of them is technically trans. What is the science here and how should sporting competitions like the Olympics deal with it?

Both female boxers have XY chromosomes (according to the IBA). For some people this means they are male, but as is often the case, it’s more complicated than that. Let’s quickly review some basic biology regarding biological sex to put this into perspective.

Male-Female develop does begin with sex chromosomes: XX for female and XY for male. Specific genes on the X and Y chromosomes affect sexual development, partly through production of sex hormones such as estrogen and testosterone. XX individuals develop ovaries and eggs, produce high estrogen and low testosterone, and develop anatomically along a typical female path with uterus, vagina, and with puberty, female secondary sexual characteristics. XY individuals develop gonads and sperm, make high testosterone, and develop along a typical male path with descended testes, penis and with puberty, male secondary sexual characteristics. All of this is part of biological sex. But also there is the potential for differences every step of the way. In addition, there are other chromosomal arrangements possible.  By some estimates about 1 in 300 people have some difference of sex development.

Yu-ting and Khelif are XY females. How does this happen? One possibility is that they have an incomplete Y chromosome, and may specifically lack the SRY gene which is necessary for male genital development. You can also have XY females who do not produce testosterone. Another possibility is complete androgen insensitivity syndrome (CAIS) in which XY individuals make testosterone but don’t have functioning receptors, so they develop as if they do not have testosterone (the default developmental pathway without testosterone is female). They typically have undescended tested, no uterus, but female external genitalia and female secondary sexual characteristics.

There are also XX females who are maculinized because they produce more androgens than is typical, such as in congenital adrenal hyperplasia. They may have ambiguous genitalia, but not always and may simply be identified female at birth. When they go through puberty, however, they can develop a deeper voice, become more hairy, and also develop more muscle mass and greater strength than a typical female.

The bottom line is that human biological sex is clearly not strictly binary. But the Olympics, like many sporting organizations, is strictly binary. How do we make these things work together? I think most people will agree we want sporting competitions to be fair and meaningful, but there can be disagreement on exactly what this means. Further, biological sex is just one of many parameters that can be affected by genetics and development that can impact sporting performance.

One question is – how much testing are we going to put athletes through to determine if they may have any genetic or developmental advantages related to sexual development? If we want at least a reasonably clear picture we would need to test for chromosomes, hormone levels, and receptor sensitivity. Such testing would be invasive and expensive, but nothing less would really show the complete picture. Also, the results would be along a spectrum, which means we would have to draw somewhat arbitrary dividing lines. Further still, who has the burden of proof to show that any particular biology has inherent advantages in any particular sport? And of course, the answer would differ for every sport – boxing and archery would not have the same biological advantages.

If we are going to open this can of worms, would it be consistent to also consider other biological factors. Heritage also impacts sports-relevant biological features. African Americans, for example, (both male and female) have higher average muscle mass and strength than Caucasians or Asians. The sex and race streams often cross, as AA women are more likely to be accused of being “too masculine”.

I am not proposing any specific answer here, just laying out the inherent complexity. There is not one right or wrong answer, just trade-offs. This is because there is an inherent disconnect between the binary world of sports and the non-binary world of human biological sex. Should we just exclude the estimated 26 million people in the world with DSD from competitive sports? Should we do very thorough biological assessments of athletes and divide them into leagues accordingly? Or do we do something in the middle, balancing various considerations to create an imperfect system that’s reasonably fair and functional?

I do think there is one thing we shouldn’t do – turn the whole thing into a culture war rife with pseudoscience and intolerance.

The post The Gender Boxing Hubub first appeared on NeuroLogica Blog.

A century ago, Albert Einstein suggested that the universe might contain ripples in space-time, known as gravitational waves – but then he changed his mind

A split in the southern vortex – not seen since 2002 – could lead to sudden warming of the Antarctic stratosphere and hotter weather in Australia and South America

Meanwhile, in Dobrzyn, Hili is schooled on the reality of life:

Hili: Why is the truth always left in the shadows? A: Because it demands concentration and fools are enchanted by the vulgar entertainment of liars.

 

 

Hili: Dlaczego prawda zostaje zawsze w cieniu?
Ja: Bo wymaga skupienia, a kłamcy urzekają głupców jarmarczną zabawą.

Two nankeen kestrels have been filmed flying in a wind tunnel to learn how the raptors keep their heads in a fixed position under turbulent conditions

As a sociologist interested in the scientific study of social life, I’ve long been concerned about the ideological bent of much of sociology. Many sociologists reject outright the idea of sociology as a science and instead prefer to engage in political activism. Others subordinate scientific to activist goals, and are unclear as to what they believe sociology’s purpose should be. Still others say different things depending on the audience.

The American Sociological Association (ASA) does the latter. Last December, the Board of Governors of Florida’s state university system removed an introductory sociology course from the list of college courses that could be taken to fulfil part of the general education requirement. It seemed clear that sociology’s reputation for progressive politics played a role in the decision. Florida’s Commissioner of Education, for example, wrote that sociology had been hijacked by political activists.1 The ASA denied the charge and went on to declare that sociology is “the scientific study of social life, social change, and the social causes and consequences of human behavior.”

While that definition certainly aligns with my vision of what sociology should be, it contrasts with another recent statement made by the ASA itself when announcing this year’s annual conference theme. The theme is “Intersectional Solidarities: Building Communities of Hope, Justice, and Joy,” which, as the ASA website explains, “emphasizes sociology as a form of liberatory praxis: an effort to not only understand structural inequities, but to intervene in socio-political struggles.”2 It’s easy to see how Florida’s Commissioner of Education somehow got the idea that sociology has become infused with ideology.

The ASA’s statement in defense of sociology as the science of social life seems insincere. That’s unfortunate— we really do need a science of social life if we’re going to understand the social world better. And we need to understand the world better if we’re going to effectively pursue social justice. The ASA’s brand of sociology as liberatory praxis leads not only to bad sociology, but also to misguided efforts to change the world. As I’ve argued in my book How to Think Better About Social Justice, if we’re going to change the world for the better, we need to make use of the insights of sociology. But bad sociology only makes things worse.

Contemporary social justice activism tends to draw from a sociological perspective known as critical theory. Critical theory is a kind of conflict theory, wherein social life is understood as a struggle for domination. It is rooted in Marxist theory, which viewed class conflict as the driver of historical change and interpreted capitalist societies in terms of the oppression of wage laborers by the owners of the means of production. Critical theory understands social life similarly, except that domination and oppression are no longer simply about economic class but also race, ethnicity, gender, religion, sexuality, gender identity, and much more.

There are two problems with social justice efforts informed by critical theory. First, this form of social justice—often called “critical social justice” by supporters and “wokeism” by detractors—deliberately ignores the insights that might come from other sociological perspectives. Critical theory, like conflict theory more broadly, is just one of many theoretical approaches in a field that includes a number of competing paradigms. It’s possible to view social life as domination and oppression, but it’s also possible to view it as a network of relationships, or as an arena of rational transactions similar to a marketplace, or as a stage where actors play their parts, or as a system where the different parts contribute to the functioning of the whole. If you’re going to change the social world, it’s important to have some understanding of how social life works, but there’s no justification for relying exclusively on critical theory.

The second problem is that, unlike most other sociological perspectives, critical theory assumes an oppositional stance toward science. This is partly because critical theory is intended not just to describe and explain the world, but rather to change it—an approach the ASA took in speaking of sociology as “liberatory praxis.” However, the problem isn’t just that critical theory prioritizes political goals over scientific ones, it’s that it also sees science as oppressive and itself in need of critique and dismantling. The claim is that scientific norms and scientific knowledge—just like other norms and other forms of knowledge in liberal democratic societies—have been constructed merely to serve the interests of the powerful and enable the oppression of the powerless.

Critical theory makes declarations about observable aspects of social reality, but because of its political commitments and its hostile stance toward scientific norms, it tends to act more like a political ideology than a scientific theory. As one example, consider Ibram X. Kendi’s assertions about racial disparities. Kendi, a scholar and activist probably best known for his book How to Be an Antiracist, has said, “As an anti-racist, when I see racial disparities, I see racism.”3 The problem with this approach is that while racism is one possible cause of racial disparities (and often the main cause!), in science, our theories need to be testable, and they need to be tested. Kendi doesn’t put his idea forward as a proposition to be tested but instead as a fundamental truth not to be questioned. In any true science, claims about social reality must be formulated into testable hypotheses. And then we need to actually gather the evidence. Usually what we find is variation, and this case is likely to be no different. That is, we’re likely to find that in some contexts racism has more of a causal role than in others.

We often want easy answers to social problems. Social justice activists might be inclined to turn to would-be prophets who proclaim what seems to be the truth, rather than to scientists who know we have to do the legwork required to understand and address things. Yes, science gives us imperfect knowledge, and it points to the difficulties we encounter when changing the world… but since we live in a world of tradeoffs, there are seldom easy answers to social problems. We can’t create a perfect world—utopia isn’t possible—so any kind of social justice rooted in reality must try to increase human flourishing while recognizing that not all problems can be eliminated, certainly not easily or quickly.

This article appeared in Skeptic magazine 29.2
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What does it all mean? For one, we should be much more skeptical about one of critical theory’s central claims— that the norms and institutions of liberal democratic societies are simply disguised tools of oppression. Do liberal ideals such as equality before the law, due process, free speech, free markets, and individual rights simply mask social inequalities so as to advance the interests of the powerful? Critical theorists don’t really subject this claim to scientific scrutiny. Instead, they take the presence of inequalities in liberal societies as selfsufficient evidence that liberalism is responsible for these failures. Yet any serious attempt to pursue social justice informed by scientific understanding of the world would involve comparing liberal democratic societies with other societies, both present and past.

Scientific sociology can’t tell us the best way to organize a society and social justice involves making tradeoffs among competing values. We may never reach a consensus on what kind of society is best, but we should consider the possibility that liberal democracies seem to provide the best framework we yet know of for pursuing social justice effectively. At the very least, they provide mechanisms for peacefully managing disputes in an imperfect world.

About the Author

Bradley Campbell is a professor of sociology at California State University, Los Angeles. He is the author The Geometry of Genocide, The Rise of Victimhood Culture (with Jason Manning), and How to Think Better About Social Justice: Why Good Sociology Matters. His research interests include moral conflict, violence, collision of right and wrong, and how they are handled. He has recently begun to examine conflicts on college campuses, manifestations of ongoing moral change, and the clash of different moral ideals.

References

1. https://bit.ly/3xxYgYb
2. https://bit.ly/3W2NKCo
3. https://bit.ly/3U2d4WK

Neutron stars (NS) are the collapsed cores of supermassive giant stars that contain between 10 and 25 solar masses. Aside from black holes, they are the densest objects in the Universe. Their journey from a main sequence star to a collapsed stellar remnant is a fascinating scientific story.

Sometimes, a binary pair of NS will merge, and what happens then is equally as fascinating.

When two NS merge, a remnant is created that either becomes a black hole or a neutron star, with the black hole being the most common result. But the eventual remnant is just part of the story. There’s a lot going on in the extreme environment created by the merger.

NS mergers can almost instantaneously create extremely powerful magnetic fields trillions of times stronger than Earth’s. They can create short gamma-ray bursts (GRBs). They create kilonovae. They create such an extreme environment that the elusive r-process, or rapid neutron capture process, can occur. The r-process is responsible for a large number of the stable element isotopes heavier than iron, including gold, platinum, and other precious metals.

New research in The Astrophysical Journal examines this extreme environment to see how the interacting forces create a remnant. Its title is “Ab-initio General-relativistic Neutrino-radiation Hydrodynamics Simulations of Long-lived Neutron Star Merger Remnants to Neutrino Cooling Timescales.” The authors are David Radice and Sebastiano Bernuzzi, both from Pennsylvania State University.

The authors say that this is the first ab-initio study into NS mergers. Ab-initio means ‘from the beginning’ in Latin. It means that their simulations are based directly on the fundamental laws of nature and don’t include empirical data. These types of simulations require extremely high levels of computing power, but the payoff is in their predictive power. Ab-initio studies can reveal aspects of complex systems that are extremely difficult to study experimentally. General-relativistic means the simulations incorporate Einstein’s theory of general relativity, which is critical for describing the extreme gravity near neutron stars.

“Despite its astrophysical relevance, the evolution of long-lived NS merger remnants past the GW-dominated phase of their evolution is poorly understood,” the authors write.

The researchers simulated the mergers of a pair of neutron stars with 1.35 solar masses each. The initial distance between the two was a mere 50 km (30 mi). The simulations covered the last ~six orbits prior to the merger and extended to more than ~100 ms after the merger.

“The research explored neutron stars’ early evolution, just moments after they were created,” the authors write. “This research is a starting point for identifying the astronomical signals that could help answer questions about neutron stars and black hole formation.”

The first phase of a neutron star merger, after the inspiral, is the gravitational wave (GW) phase. It lasts until about 20 milliseconds after the merger. By releasing GWs, the neutron star releases some of the merger’s energy.

The next phase is the neutrino cooling phase, and it’s the focus of this work. “We find that neutrino cooling becomes the dominant energy loss mechanism after the gravitational-wave dominated phase (?20 ms postmerger),” the authors write.

This figure shows the possible stages of a neutron star merger. It doesn’t show the neutrino cooling phase but does show the viscous phase. Viscosity arises in the remnant due to turbulence and plays key roles in mass ejection and the merger’s outcome: usually a black hole but sometimes a stable NS. Image Credit: Radice D et al. 2020.

Neutrinos are elusive particles that are electrically neutral and have very small masses. According to some research, about 400 billion neutrinos pass through every person on Earth each second. Despite their lack of interaction, neutrinos do carry energy away from the merger, and their energy level depends on the process that formed them. Over time, that energy decays.

A neutron star merger usually creates a black hole remnant. But sometimes, it creates another neutron star called an RMNS, or remnant massive neutron star.

“The neutrino luminosities decay more slowly, so 10–20 ms after merger neutrinos, they become the dominant mechanism through which energy is lost by the RMNS,” the authors write.

This figure from the research shows the GW (red) and neutrino (blue) cooling timescales. About 10 ms after the merger, neutrino radiation becomes the dominant mechanism in the evolution of the remnant. Image Credit: Radice et al. 2024.

The simulations show that the RMNS is different than the protoneutron stars created when massive stars collapse.

The merger creates a dense gas of electron antineutrinos in the RMNS’s outer core. This correlates with hot spots on the outer core. The RMNS is also stable against convection despite the surface being hotter than the core. If there were convective instabilities, they could trigger more GW emissions, but according to the authors, the simulations didn’t show that. “We find no evidence for a revival of the GW signal due to convective instabilities,” they write.

Some research shows that merging NSs are the sources of short gamma-ray bursts (SGRBs.) But for that to happen, the magnetic field needs to somehow escape the remnant and form larger magnetic fields. “If RMNSs are a viable central engine for SGRBs, then the field needs somehow to bubble out of the remnant and form large-scale magnetic structures,” the authors write. But the RMNS’s stability seems to rule that out. “However, our simulations indicate that the RMNS is stably stratified, so it remains unclear how the magnetic fields can emerge from it,” the authors explain.

The merger also creates a massive accretion disk in its outer core.

“A massive accretion disk is formed by the ejection of material squeezed out of the collisional interface between the two stars, forming a massive disk in the first ?20 ms after the merger,” the researchers explain. This disk carries a large portion of the merger’s angular momentum. This allows the RMNS to settle into a fairly stable equilibrium within one of several possible stable configuration regions in the disk.

Illustration showing the merger of two neutron stars. Credit: NASA’s Goddard Space Flight Center/CI Lab

Stable neutron stars are far less common outcomes of mergers than black holes. It only occurs if the combined mass is below a maximum stable mass. But some of the details of how this happened have been obscured.

“These findings reveal a central object surrounded by a rapidly rotating ring of hot matter. If these remnants avoid collapse, scientists expect that they release the majority of their internal energy within seconds of when they form,” the authors write.

Estimates show that as few as 10% of neutron star mergers result in RMNSs, so they’re comparatively rare. By exploring the early evolution of RMNSs, this research has established a starting point for identifying the astronomical signals that can tell scientists more about neutron star mergers and how black holes are created from mergers.

By opening a new window into the fractions of a second that follow a merger, the researchers have also shown the forces involved in creating a very rare object: a stable, remnant massive neutron star.

The post The Aftermath of Neutron Star Mergers appeared first on Universe Today.