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venerdì 16 novembre 2018

# astro: a "zombie" star as a homing beacon to detect classes of black holes

<< The research explored whether a dormant white dwarf star-sometimes referred to as a "zombie" star-could reignite if it had a close encounter with an intermediate-mass black hole. >>

<< If the stars align, so to speak, a zombie star could serve as a homing beacon for a never-before-detected class of black holes. >>

<< The stretching phenomena can be very complicated (..) Imagine a spherical star approaching a black hole. As it approaches the black hole, tidal forces begin to compress the star in a direction perpendicular to the orbital plane, reigniting it. But within the orbital plane, these gravitational forces stretch the star and tear it apart. It's a competing effect. >> Rob Hoffman

<< It was exciting to see that the zombie star reignited in each of the close encounter scenarios we looked at, >> Peter Anninos

Nolan O'brien. 'Zombie' stars return from the dead. Lawrence Livermore National Laboratory. Oct 31, 2018.

https://m.phys.org/news/2018-10-zombie-stars-dead.html

Peter Anninos, P. Chris Fragile, et al. Relativistic Tidal Disruption and Nuclear Ignition of White Dwarf Stars by Intermediate-mass Black Holes. The Astrophysical Journal, Volume 865, Number 1. Sep 17, 2018. doi: 10.3847/1538-4357/aadad9.

http://iopscience.iop.org/article/10.3847/1538-4357/aadad9/meta  

giovedì 15 novembre 2018

# zen: effects of meditation and music on cellular aging and Alzheimer's disease

<< Telomere length (TL), telomerase activity (TA), and plasma amyloid-β (Aβ) levels have emerged as possible predictors of cognitive decline and dementia. >>

<< Practice of simple mind-body therapies may alter plasma Aβ levels, TL, and TA. Biomarker increases were associated with improvements in cognitive function, sleep, mood, and QOL (quality of life), suggesting potential functional relationships. >>

Innes Kim, Selfe Terry Kita, et al. Effects of Meditation and Music-Listening on Blood Biomarkers of Cellular Aging and Alzheimer’s Disease in Adults with Subjective Cognitive Decline: An Exploratory Randomized Clinical Trial. Journal of Alzheimer's Disease. Oct 11, 2018. doi: 10.3233/JAD-180164.

https://content.iospress.com/articles/journal-of-alzheimers-disease/jad180164

Meditation and music may alter blood markers of cellular aging and Alzheimer's disease. IOS Press. Nov 13, 2018.

https://m.medicalxpress.com/news/2018-11-meditation-music-blood-markers-cellular.html

martedì 13 novembre 2018

# behav: brain; neural cells tuned to posture

AA << identified neurons in the posterior parietal cortex and the frontal motor cortex that were associated with changes in posture. So close were the associations that the researchers could actually predict which posture a rat was assuming by simply watching neural activity in these two brain regions. >>

In a Perspective piece, Guifen Chen << wonders if neurons associated with posture become active only when a posture is achieved, or if they continue firing as that posture is held in place. >>

Bob Yirka. Researchers find neural cells in rat brain that are tuned to posture. Medical Xpress. Nov 2, 2018.

https://m.medicalxpress.com/news/2018-11-neural-cells-rat-brain-tuned.html

Bartul Mimica, Benjamin A. Dunn, et al.  Efficient cortical coding of 3D posture in freely behaving rats. Science  02 Nov 2018: Vol. 362, Issue 6414, pp. 584-589
DOI: 10.1126/science.aau2013.

http://science.sciencemag.org/content/362/6414/584 

Guifen Chen. Identifying posture cells in the brain. Science  02 Nov 2018:
Vol. 362, Issue 6414, pp. 520-521
DOI: 10.1126/science.aav3819.

http://science.sciencemag.org/content/362/6414/520 

lunedì 12 novembre 2018

# climate: AMOC (Atlantic Meridional Overturning Circulation) slowdown debate.

<< A few weeks ago, [AA] argued [..] that the Atlantic overturning circulation (sometimes popularly dubbed the Gulf Stream System) has weakened significantly since the late 19th Century, with most of the decline happening since the mid-20th Century >>

<< But there were also some questions and criticisms in the media, so [they would like] to present a forum for discussing these questions >>

If you doubt that the AMOC [Atlantic Meridional Overturning Circulation] has weakened, read this. stefan @ 28 May 2018.

http://www.realclimate.org/index.php/archives/2018/05/if-you-doubt-that-the-amoc-has-weakened-read-this/

L. Caesar, S. Rahmstorf, et al. Observed fingerprint of a weakening Atlantic Ocean overturning circulation. Nature. 556 191–196 (2018).

https://www.nature.com/articles/s41586-018-0006-5

venerdì 9 novembre 2018

# psych: birds of a feather flock together; why there are dysfunctional politicians.

“If we have dysfunctional politicians, it’s because we have a dysfunctional electorate,"

Paul Ratner. Neil deGrasse Tyson Explains Why We Have Dysfunctional Politicians. March 10, 2017.

https://bigthink.com/paul-ratner/neil-degrasse-tyson-reveals-what-he-would-do-as-president  

Also

<< A study found that people with psychopathic traits are more likely to be attracted to others on the same psychopathic spectrum. >>

<< Psychopathic qualities include lack of empathy, lack of remorse, and other antisocial traits. >>

<< Psychopathic traits aren't that attractive to non-psychopathic individuals. >>

Mike Colagrossi. Psychopaths are attracted to other psychopaths. New psychological research suggests that psychopaths are attracted to others with their same disposition. Nov 2, 2018.

https://bigthink.com/sex-relationships/psychopaths-are-attracted-to-other-psychopaths

Ashley L. Watts  Jessica C. Rohr, et al. Do psychopathic birds of a feather flock together? Psychopathic personality traits and romantic preferences. Journal of Personality. April 16, 2018. doi: 10.1111/jopy.12394.

https://onlinelibrary.wiley.com/doi/abs/10.1111/jopy.12394

mercoledì 7 novembre 2018

# astro: the strange behavior of Oumuamua (Hawaiian for "scout")

<<  'Oumuamua (1I/2017 U1) is the first object of interstellar origin observed in the Solar system. >>

AA << discuss the possible origins of such an object including the possibility that it might be a lightsail of artificial origin. >>

Shmuel Bialy, Abraham Loeb. Could Solar Radiation Pressure Explain 'Oumuamua's Peculiar Acceleration? arXiv:1810.11490 [astro-ph.EP]. Oct 30, 2018.

https://arxiv.org/abs/1810.11490

Robby Berman. Harvard scientists suggest 'Oumuamua is an alien device. It's an asteroid, it's a comet, it's actually a spacecraft? Nov 6, 2018.

https://bigthink.com/surprising-science/oumuamua-spacecraft-alien-device

NASA utd about 'Oumuamua:

Calla Cofield. NASA Learns More About Interstellar Visitor 'Oumuamua. Nov. 14, 2018.

https://www.nasa.gov/feature/jpl/nasa-learns-more-about-interstellar-visitor-oumuamua




martedì 6 novembre 2018

# gst: how a bubble pops

<< After a bubble bursts at a liquid surface, the collapse of the cavity generates capillary waves, which focus on the axis of symmetry to produce a jet. >>

AA << show that the time-dependent profiles of cavity collapse (..) and jet formation (..) both obey a  inviscid scaling, which results from a balance between surface tension and inertia forces. >>

Ching-Yao Lai, Jens Eggers, and Luc Deike. Bubble Bursting: Universal Cavity and Jet Profiles. Phys. Rev. Lett. 121, 144501. Oct 2, 2018

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.121.144501  

John Sullivan. Math describes how bubbles pop. Princeton University. Oct 31, 2018.

https://m.phys.org/news/2018-10-math.html