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Monster black holes are silencing star formation across the universe

Giant black holes may be secretly controlling how entire clusters of galaxies grow. A blazing supermassive black hole can influence far more than its own galaxy. Scientists found that quasars emit radiation strong enough to shut down star formation in nearby galaxies millions of light-years away. This could explain why some galaxies near early quasars appear faint or missing. The finding suggests galaxies grow and evolve together, not in isolation.

Powerful radiation from active supermassive black holes, which are believed to sit at the center of most galaxies, can do more than shape their own surroundings. A new study led by Yongda Zhu at the University of Arizona suggests these black holes can also slow the formation of stars in galaxies located millions of light-years away.

“Traditionally, people have thought that because galaxies are so far apart, they evolve largely on their own,” said Zhu, the study’s lead author, whose findings were published in The Astrophysical Journal Letters. “But we found that a very active, supermassive black hole in one galaxy can affect other galaxies across millions of light-years, suggesting that galaxy evolution may be more of a group effort.”

Local cues, local killers: human natural killer cells across tissues

Human natural killer cells across tissues.

Natural killer cells residing in tissues are distinct compared to those in the bloodstream, and their diversity is likely shaped by the microenvironment of individual tissues.

In tissues, natural killer cells are exposed to an environment with low oxygen levels, a distinct cytokine milieu, and different neighboring cells compared to their circulating counterparts, leading to a unique metabolic and functional profile.

Tissue-resident natural killer cells in most human tissues appear to be only transiently tissue-resident and recirculate via the lymphatic system back to the bloodstream. Lymphatic vessels and lymph nodes contain various natural killer cell populations of distinct origins. Tumor responses of tissue-resident natural killer cells depend on the tissue niche and tumor microenvironment context, with tissue-resident natural killer cells having a more immunoregulatory rather than a direct cytotoxic role during tumorigenesis. sciencenewshighlights ScienceMission https://sciencemission.com/natural-killer-cells


Natural killer (NK) cells are part of the innate immune system and reside in multiple tissues. During steady-state conditions, they contribute to tissue homeostasis, while in disease settings, tissue-resident (tr) NK cells are positioned at the frontline of immune surveillance. Due to their exposure to local microenvironments, NK cells residing outside the bloodstream exhibit phenotypic, transcriptional, functional, and metabolic features that distinguish them from their circulating counterparts. In this review, we outline the defining characteristics of tr NK cells, discuss their recirculation potential, and summarize their functional and metabolic specialization across human tissues. Finally, using cancer as an example, we highlight how tr NK cells are altered in disease and how local tissue environments shape their functional states.

B cell deficiency limits exercise capacity by remodeling liver glutamate metabolism

Now online! B cells regulate exercise capacity through immune-independent liver-muscle metabolic signaling, and B cell deficiency limits muscle performance. Mechanistically, B cell-secreted TGF-β1 increases hepatic glutamine-to-glutamate conversion, raising glutamate in blood and muscle. This promotes muscle calcium signaling and mitochondrial function, positively regulating exercise capacity.

#Polymath

This is one of my favourite comparisons: polymathy is cognitive biodiversity.

Monoculture farming depletes soil, invites disease, collapses under pressure. One blight, one drought and the whole field dies.

Why do we accept the same fragility in how we think?

The specialist mind is similar to a monoculture. Trained to the depth in one domain and optimized for known conditions. When the paradigm breaks, it can only do what it has always done.

Physicists Propose a New Kind of Laser That Would Fire Neutrinos

Physicists have proposed a new way to make neutrinos at accelerated rates. This method would use a state of matter close to absolute zero called a Bose-Einstein condensate. It would harness quantum effects that can produce neutrinos faster than ordinary radioactive decays. This tool would produce a large and controllable beam of neutrinos. They could have similar properties to photons (particles of light) in an optical laser.

Neutrinos are fundamental particles that interact extremely weakly with matter. It is very difficult to produce and detect neutrinos. It requires large detectors and powerful sources such as nuclear reactors or particle accelerators. A controllable, coherent source of neutrinos on a bench-top scale would have a significant impact on neutrino research. This type of technology would provide new opportunities to understand their interactions and quantum mechanical properties. In addition, the specific radioactive decays that would enable such a controllable, coherent neutrino source on a small scale could lead to new applications. These applications could include production of rare isotopes for medical physics and neutrino-based communication.

Lasers have been revolutionary in enabling the development of many aspects of modern science and technology. They are based on the amplification of light via stimulated emission. This is a quantum mechanical process whereby an excited atom is forced to emit a second photon upon absorption of another with the same wavelength. Due to their tiny masses, neutrinos behave similarly to photons in many situations. However, they cannot be used for lasing because their fermionic nature inhibits stimulated emission. For this reason, it is not possible to develop a neutrino laser using this traditional mechanism.

Can Time Be Negative in Quantum Mechanics?

Physicists explored the concept of negative time, finding it wasn’t just an illusion but potentially described actual physical phenomena. Discover the surprising results of quantum trajectory calculations. #Physics #Science #QuantumMechanics #NegativeTime Full podcast with Prof. Aephraim Steinberg: https://youtu.be/cOZ3Kto6NIc

Blinding Integrity in Psychedelic Randomized Clinical Trials: A Systematic Review

Functional unblinding was common in most psychedelic randomized clinical trials for psychiatric disorders, with 70% correctly identifying treatment allocation, raising concerns for trial validity.


Question What is the prevalence of blinding integrity assessment and the extent of functional unblinding in psychedelic randomized clinical trials (RCTs) for psychiatric disorders?

Findings Of 112 RCTs identified, 29.5% (n = 33) evaluated blinding integrity. Functional unblinding was substantial: psilocybin, lysergic acid diethylamide (LSD), and ayahuasca studies frequently reported blinding failure values of more than 90% among participants and raters; inert placebo-controlled 3,4-methylenedioxymethamphetamine (MDMA) trials exceeded 85%; ketamine trials rarely assessed blinding (17.9%) but showed improved preservation with midazolam vs saline controls.

Meaning Functional unblinding is pervasive in psychedelic RCTs, underscoring the need for standardized assessment methods and improved trial designs to ensure valid efficacy evaluations.

Songbird connectome reveals tunneling of migratory neurons in the adult striatum

Despite its small size—typically only several inches, beak to tail—the zebra finch is a remarkable learner. A songbird native to Australia, it’s renowned for its ability to pick up new songs.

That talent has made it a favorite of scientists studying how animal brains imprint new skills, particularly vocal learning, or the capacity to perfect new sounds. And now researchers at Boston University have discovered another quirk to the zebra finch brain—one that could also have implications for understanding our own gray matter.

In a study that looked at the bird’s brain in unprecedented detail, they uncovered new insights into a mechanism known as neurogenesis—the birth, migration, and maturation of neurons—that may help the brain learn, add new skills, and restore and repair itself.

Observing the finch brain using a high-powered microscope, the researchers watched as new neurons bullied their way through the brain en route to bolstering existing circuits and connections. They’d expected the neurons to gingerly step around established brain structures, including more mature brain cells, to better preserve them; instead, they saw the neurons tunnel right through, squishing and shoving as they went. That may help the birds learn new things or repair damage, but it could also come with a cost to existing cells and memories.

According to the BU-led team, their findings could help explain why neurogenesis may not occur in humans beyond the womb, increasing our vulnerability to a range of brain disorders. The findings were published in Current Biology.

Abstract: Current Biology

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