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giovedì 25 gennaio 2018

# astro: unexpectedly large dust and gas inside

<< Despite having low star formation rates, the elliptical galaxies contain surprisingly large amounts of gas: 100 times more than was expected. This is surprising in two ways. It challenges our standard view of elliptical galaxies as “boring” gas-poor objects. But it also forces us to rethink the basic view of star formation processes – we have always assumed that the presence of cold gas must lead to star formation. Here, we find that elliptical galaxies form stars far less efficiently than disk galaxies at the same epoch. >>

Marie Martig. Study of distant galaxies challenges our understanding of how stars form. Jan 19, 2018.

https://theconversation.com/study-of-distant-galaxies-challenges-our-understanding-of-how-stars-form-90147  

Gobat R, Daddi E, et al.  The unexpectedly large dust and gas content of quiescent galaxies at z > 1.4. Nature Astronomy. doi: 10.1038/s41550-017-0352-5. Jan 15, 2018.

https://www.nature.com/articles/s41550-017-0352-5 

mercoledì 24 gennaio 2018

# gst: the generation of waves by random point sets

<< amorphous Chern insulators can be readily constructed from arbitrary underlying structures, including hyperuniform, jammed, quasi-crystalline and uniformly random point sets >>

Noah P. Mitchell, Lisa M. Nash, et al.  Amorphous topological insulators constructed from random point sets.
Nature Physics (2018)
doi: 10.1038/s41567-017-0024-5.
Jan 15, 2018

https://www.nature.com/articles/s41567-017-0024-5

<< You don't have to be perfectly organized to pull off a wave >>

Gyroscopes lead scientists to unusual state of matter in a disorganized structure. Jan 15, 2018.

https://m.phys.org/news/2018-01-gyroscopes-scientists-unusual-state-disorganized.html  

martedì 23 gennaio 2018

# brain: auditory performance also oscillates

AA << demonstrate that, as with vision, both auditory sensitivity and criterion showed strong oscillations over time, at different frequencies: ∼6 Hz (theta range) for sensitivity and ∼8 Hz (low alpha range) for criterion, implying distinct underlying sampling mechanisms. The modulation in sensitivity in left and right ears was in antiphase, suggestive of attention-like mechanisms sampling alternatively from the two ears. >>

Hao Tam Ho, Johahn Leung, et al. Auditory Sensitivity and Decision Criteria Oscillate at Different Frequencies Separately for the Two Ears.  Current Biology. 2017;  27 (23): 3643 -9.e3. doi: 10.1016/j.cub.2017.10.017. Nov 16, 2017.

http://www.cell.com/current-biology/fulltext/S0960-9822(17)31320-9

<< perception is cyclical. In a new study, researchers report that, much like visual perception, auditory perception and attention are rhythmic in nature >>

Researchers Discover the Brain is Strobing, Not Constant.

http://neurosciencenews.com/strobing-brain-7970/amp/

lunedì 22 gennaio 2018

# astro: asteroids, about small NEO (Near Earth Objects)

<< One of the major problems that civilisation has is that while we are becoming incredibly efficient at spotting Near Earth Objects, we still cannot do anything about one that might be on a collision path with the Earth. NASA currently has a project, DART (Double Asteroid Redirection Test), to redirect a threatening asteroid at the preliminary design phase. >>

<< It is salutary to look at the number of detections of Near Earth Objects. The Minor Planet Center maintains a database of observations, keeping a running total which, by the end of December 2017, stood at over 17,500. A further 28 have already been spotted this month. >>

Monica Grady. A huge asteroid wiped out the dinosaurs, but what danger do smaller ones pose? Jan 18, 2018.

https://theconversation.com/a-huge-asteroid-wiped-out-the-dinosaurs-but-what-danger-do-smaller-ones-pose-90133   

sabato 20 gennaio 2018

# gst: chaotic dynamics in the transition between sleep and wakefulness

AA <<  have investigated how to describe one of the most significant state changes in the brain, namely the transition between sleep and wakefulness >>

<< The brain's neuronal activity depends on the overall state we are in (deep sleep, light sleep, sedentary awake or awake and active), and this is important for how sensory impressions are processed >>

Niels  Bohr  Institute. Chaos  in  the  transition from sleep to awake. Dec 15,  2017.

https://m.medicalxpress.com/news/2017-12-chaos-transition.html

AA << find that sleep is governed by stable, self-sustained oscillations in neuronal firing patterns, whereas the quiet awake state and active awake state are both governed by irregular oscillations and chaotic dynamics; transitions between these separable awake states are prompted by ionic changes. Although waking is indicative of a shift from stable to chaotic neuronal firing patterns, [AA]  illustrate that the properties of chaotic dynamics ensure that the transition between states is smooth and robust to noise >>

Rune Rasmussen, Mogens H. Jensen, Mathias L. Heltberg. Chaotic Dynamics Mediate Brain State Transitions, Driven by Changes in Extracellular Ion Concentrations.
Cell Systems. 2017; 5 (6): 591 - 603.e4. doi: 10.1016/j.cels.2017.11.011. Dec 13, 2017.

http://www.cell.com/cell-systems/fulltext/S2405-4712(17)30539-2

giovedì 18 gennaio 2018

# behav: the self-medication poultice by orang-utans (Pongo pygmaeus)

<< Animals self-medicate using a variety of plant and arthropod secondary metabolites by either ingesting them or anointing them to their fur or skin apparently to repel ectoparasites and treat skin diseases >>

AA << document self-medication in the only Asian great ape, orang-utans (Pongo pygmaeus), and for the first time, to our knowledge, the external application of an anti-inflammatory agent in animals. The use of leaf extracts from Dracaena cantleyi by orang-utan has been observed on several occasions; rubbing a foamy mixture of saliva and leaf onto specific parts of the body. Interestingly, the local indigenous human population also use a poultice of these leaves for the relief of body pains >>

Morrogh-Bernard HC, Foitova I, et al. Self-medication by orang-utans (Pongo pygmaeus) using bioactive properties of Dracaena cantleyi. Scientific Reports. 2017; 7: 16653.
doi: 10.1038/s41598-017-16621-w.
Nov 30, 2017.

https://www.nature.com/articles/s41598-017-16621-w

Borneo Nature Foundation. Orangutans, like people, use medicinal plants to treat joint and muscle inflammation. Jan 10, 2018.

https://m.phys.org/news/2018-01-orangutans-people-medicinal-joint-muscle.html

mercoledì 17 gennaio 2018

# age: lifespan in the elderly throughout history

<< People sometimes think that in those days if you lived to 40 that was about as good as it got. But that's not true. For people living traditional lives without modern medicine or markets the most common age of death is about 70, and that is remarkably similar across all different cultures >> Christine Cave.

Redefining knowledge of elderly people throughout history. Jan 4, 2018.

https://m.phys.org/news/2018-01-redefining-knowledge-elderly-people-history.html

Christine M.Cave, Marc F.Oxenham. Sex and the elderly: Attitudes to long-lived women and men in early Anglo-Saxon England. Journal of Anthropological Archaeology. 2017; 48: 207-16.  doi: 10.1016/j.jaa.2017.08.003. Sept 4, 2017.

http://www.sciencedirect.com/science/article/pii/S0278416517300648