Translate

mercoledì 31 gennaio 2018

# brain: self-evaluation of one's own ignorance

<< Self-evaluation of one's own ignorance requires us to peer into our own mind retrospectively. [AA] found that only the bilateral frontopolar cortices (area 10) are recruited for metacognitive evaluation of non-experienced events in macaque monkeys performing metacognitive confidence judgment on memory >>

Kentaro Miyamoto, Rieko Setsuie, et al. Reversible Silencing of the Frontopolar Cortex Selectively Impairs Metacognitive Judgment on Non-experience in Primates.
Neuron. doi: 10.1016/j.neuron. 2017.12.040. Jan 25, 2018.

http://www.cell.com/neuron/fulltext/S0896-6273(17)31208-4

Cognitive Neuroscience and the Awareness of Ignorance. Jan 27, 2018.

https://neurosciencenews.com/ignorance-awareness-8383

lunedì 29 gennaio 2018

# chem: extreme superconductive in random atomic-scale mixture

<< High-entropy alloys (HEAs) are a new class of materials that are composed of multiple transition-metal elements in equimolar or near-equimolar ratios >>

<< many HEAs have been found in disordered solid-solution phases with body-centered-cubic, hexagonal closest-packed, and face-centered-cubic crystal structures >>

<< In many respects, HEAs display novel properties, including ultrahigh fracture toughness at cryogenic temperatures, excellent specific strength, and superior mechanical performance at high temperatures. In addition to their promising mechanical properties, some HEAs also exhibit interesting electronic properties: [TaNb]1−x(ZrHfTi)x HEAs were found to display superconductivity, for example >>

AA << report high-pressure studies on the superconducting HEA (TaNb)0.67(HfZrTi)0.33, [..] this alloy exhibits extraordinarily robust superconductivity - its zero-resistance superconducting state is still achieved even at a pressure of 190.6 GPa, or almost 2 megabars (1 Mbar = 1011 pascal), a pressure like that within the outer core of the earth. >>

Jing Guo, Honghong Wang, et al.  Robust zero resistance in a superconducting high-entropy alloy at pressures up to 190 GPa. PNAS 2017; 114 (50) 13144-7.  doi: 10.1073/pnas.1716981114.

http://www.pnas.org/content/114/50/13144

Laura Mgrdichian. A material that superconducts continuously up to extreme pressures.  Jan 17, 2018

https://m.phys.org/news/2018-01-material-superconducts-extreme-pressures.html

sabato 27 gennaio 2018

# acad: scientific community as a club

<< People think that the scientific community is agnostic, but as with any established institution, be it the boardroom, Wall Street, or Hollywood, it's a club, and it's up to us to change the rules of getting into that club. >> Emilio Bruna.

As science becomes more international, scientific editorial boards lag behind. Dec 12, 2017.

https://m.phys.org/news/2017-12-science-international-scientific-editorial-boards.html

<< The scholars comprising journal editorial boards play a critical role in defining the trajectory of knowledge in their field. Nevertheless, studies of editorial board composition remain rare, especially those focusing on journals publishing research in the increasingly globalized fields of science, technology, engineering, and math (STEM). >>

Johanna Espin, Sebastian Palmas, et al. A persistent lack of international representation on editorial boards in environmental biology.  PLOS Biology 15(12): e2002760. doi: 10.1371/journal.pbio.2002760. Dec 12, 2017.

http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2002760

venerdì 26 gennaio 2018

# gst: semantic vs Shannon information

<< "Making Sense: Information as Meaning,” which proposes that meaning “be considered the output of the interpretive process of which information is the input.” David Haig.

<< Haig’s ideas may be the basis for getting us all the way from molecules to poets and scientists and philosophers while keeping the same definitions of information, interpretation, and meaning throughout >>  Dan Dennett.

Jenna Marshall. Reconciling two views of information. SFI. Jan 18, 2018.

https://santafe.edu/news-center/news/reconciling-two-views-information

also

1850 - attrattore semantico

http://inkpi.blogspot.it/2004/12/1850-attrattore-semantico.html

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

martedì 16 gennaio 2018

# acad: new research must be better reported

<< Yet all too often research-led stories start with "researchers have found", with little mention of their names, institution and who funded their work. And the problem is that by reporting new research in this way, it fails to break down the stereotypical image of an ivory tower >>

Andy Tattersall. New research must be better reported, the future of society depends on it. Jan 8, 2018.

https://theconversation.com/new-research-must-be-better-reported-the-future-of-society-depends-on-it-87407

lunedì 15 gennaio 2018

# sec: sometimes the repair is crippling ...

<< Microsoft has temporarily stopped fixing a serious security flaw on personal computers powered by certain chips from Advanced Micro Devices because the repair is crippling the affected machines >>

Microsoft stops fixing security flaw on PCs with AMD chips. Jan 9, 2018.

https://m.phys.org/news/2018-01-microsoft-flaw-pcs-amd-chips.html

Windows operating system security update block for some AMD based devices. Jan 10, 2018.

https://support.microsoft.com/en-us/help/4073707/windows-os-security-update-block-for-some-amd-based-devices

sabato 13 gennaio 2018

# brain: rhythm-regulation and plasticity through oscillations

<< During inattentive wakefulness and non-rapid eye movement (NREM) sleep, the neocortex and thalamus cooperatively engage in rhythmic activities >>

<< thalamic oscillations of low-vigilance states have a plasticity function that (..) can shape ongoing oscillations during inattention and NREM sleep and may potentially reconfigure thalamic networks for faithful information processing during attentive wakefulness >>

Vincenzo Crunelli, Magor L. Lorincz, et al. Dual function of thalamic low-vigilance state oscillations: rhythm-regulation and plasticity. Nature Reviews Neurosci doi: 10.1038/nrn.2017.151. Jan 11, 2018

https://www.nature.com/articles/nrn.2017.151

venerdì 12 gennaio 2018

# chem: oddities under pressure

<< When [AA] placed the material inside a gas chamber and cranked up the air pressure from one bar (about the atmospheric pressure at sea level) to five bars, the cube’s volume increased by about 3 percent >>

Maria Temming. This material does weird things under pressure. Microcube is designed so that pressure makes it expand instead of compress. Science News. 2017; 192 (11): 12. Dec 23, 2017.

https://www.sciencenews.org/article/material-does-weird-things-under-pressure 

Jingyuan Qu, Alexander Gerber, et al. Experiments on Metamaterials with Negative Effective Static Compressibility. Phys. Rev. 2017; X7, 041060. Dec 8, 2017

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.7.041060

martedì 9 gennaio 2018

# behav: some birds discovered fire before humans did

<< There are many anecdotes about Australian birds of prey using fire, according to ornithologist Bob Gosford at the Central Land Council in Alice Springs, Northern Territory >>

<< The three species mentioned are black kites (Milvus migrans), whistling kites (Haliastur sphenurus) and brown falcons (Falco berigora) >>

Andy Coghlan. Arsonist falcons suggest birds discovered fire before humans did. Jan 5, 2018.

https://www.newscientist.com/article/2157887-arsonist-falcons-suggest-birds-discovered-fire-before-humans-did

lunedì 8 gennaio 2018

gst: some origami won't fold under pressure

<< Why is it difficult to refold a previously folded sheet of paper? [AA] show that even crease patterns with only one designed folding motion inevitably contain an exponential number of "distractor" folding branches accessible from a bifurcation at the flat state >>

Menachem Stern, Matthew B. Pinson, Arvind Murugan. The Complexity of Folding Self-Folding Origami. Phys. Rev. X 7, 041070 – Dec 22, 2017.

https://journals.aps.org/prx/abstract/10.1103/PhysRevX.7.041070

Louise Lerner. Scientists lay out why some origami won't fold under pressure. Jan4, 2018.

https://m.phys.org/news/2018-01-scientists-origami-wont-pressure.html

mercoledì 3 gennaio 2018

# behav: to avoid a rat race

<< Mice can learn to overcome their naturally aggressive approach to conflict resolution, instead adopting a cooperative strategy >>

AA << demonstrate that pairs of mice can learn to coordinate their behaviour to achieve an egalitarian distribution of rewards — but only when rewards are delivered directly to the brain, rather than through food >>

Scott M. Rennie, Michael. L. Platt. Mice learn to avoid the rat race. Nature News and Views. Dec 21, 2017.

https://www.nature.com/articles/d41586-017-08835-9  

Choe Il-Hwan, Byun Junweon, et al. Mice in social conflict show rule-observance behavior enhancing long-term benefit. Nature Comm. 2017;  8 (1176).  doi: 10.1038/s41467-017-01091-5.  Nov 07, 2017

https://www.nature.com/articles/s41467-017-01091-5