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mercoledì 19 luglio 2017

# s-chem: self-assembling 'origami' nanoscale architectures by DNA staple strands

<< DNA origami is a technique that uses hundreds of short DNA oligonucleotides, called staple strands, to fold a long single-stranded DNA, which is called a scaffold strand, into various designer nanoscale architectures >>

Hong F, Zhang F, et al. DNA Origami: Scaffolds for Creating Higher Order Structures. Chem Rev. 2017 Jun 12. doi: 10.1021/acs.chemrev.6b00825.

https://www.ncbi.nlm.nih.gov/pubmed/28605177

martedì 18 luglio 2017

# s-behav: disruptive colouration to gain cryptic benefits (among the reef fish Dascyllus aruanus)

<< Animals use disruptive colouration to prevent detection or recognition by potential predators or prey. Highly contrasting elements within colour patterns, including vertical or horizontal bars, are thought to be effective at distracting attention away from body form and reducing detection likelihood. >>

AA << results provide evidence that fish camouflage is more complex than it initially appears, with likely many factors influencing the detection likelihood of prey by relevant predators >>

Phillips GAC, How MJ, et al. Disruptive colouration in reef fish: does matching the background reduce predation risk?  J Exp Biol. 2017 Jun 1;220 (Pt 11): 1962-1974 doi: 10.1242/jeb.151480

https://www.ncbi.nlm.nih.gov/pubmed/28566354

lunedì 17 luglio 2017

# s-gene: epigenetics, more than just genes

<< We are more than the sum of our genes. Epigenetic mechanisms modulated by environmental cues such as diet, disease or lifestyle take a (..) role in regulating the DNA by switching genes on and off >>

AA << focused on a particular modification called H3K27me3 that can also be found in humans >>

Max Planck Society. Epigenetics between the generations: Researchers prove that we inherit more than just genes. July 14, 2017

https://medicalxpress.com/news/2017-07-epigenetics-inherit-genes.html

Fides Zenk, Eva Loeser, et al. Germ line–inherited H3K27me3 restricts enhancer function during maternal-to-zygotic transition. Science  14 Jul 2017: Vol. 357, Issue 6347, pp. 212-216 doi: 10.1126/science.aam5339

http://science.sciencemag.org/content/357/6347/212

sabato 15 luglio 2017

# s-behav: mafia-style among Cuckoos (the brown-headed cowbird Molothrus ater)

<< Why do many hosts accept costly avian brood parasitism even when parasitic eggs and nestlings differ dramatically in appearance from their own? Scientists argue that evolutionary lag or equilibrium can explain this evolutionary enigma. Few, however, consider the potential of parasitic birds to enforce acceptance by destroying eggs or nestlings of hosts that eject parasitic eggs and thereby reject parasitism.  This retaliatory “mafia” behavior has been reported in one species of parasitic cuckoo but never in parasitic cowbirds. >>

AA << present experimental evidence of mafia behavior in the brown-headed cowbird (Molothrus ater ) >>

Jeffrey P. Hoover, Scott K. Robinson. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs. PNAS 2007 vol. 104 no. 11: 4479–4483  doi: 10.1073/pnas.0609710104

http://m.pnas.org/content/104/11/4479

Andy Coghlan. Cuckoos use mafia-style tactics to raise young.  March 5, 2007

https://www.newscientist.com/article/dn11314-cuckoos-use-mafia-style-tactics-to-raise-young/

Brown-headed cowbird

https://en.m.wikipedia.org/wiki/Brown-headed_cowbird

venerdì 14 luglio 2017

# e-tech: store data with CRISPR–Cas tech.; biologists have now joined the party

<< Internet users have a variety of format options in which to store their movies, and biologists have now joined the party. Researchers have used the microbial immune system CRISPR–Cas to encode a movie into the genome of the bacterium Escherichia coli. >>

<< “Cells have this privileged access to all sorts of information,” he [Seth Shipman] says. “I would like to have these molecular recordings functioning in the developing nervous system and recording information.” >>

Heidi Ledford. Lights, camera, CRISPR: Biologists use gene editing to store movies in DNA. Technique demonstrated in E. coli suggests ways to record key events in a cell's life. July 12, 2017

http://www.nature.com/news/lights-camera-crispr-biologists-use-gene-editing-to-store-movies-in-dna-1.22288

Shipman, S. L., Nivala, J., et al. Nature doi: 10.1038/nature23017 (2017).

https://www.nature.com/articles/nature23017.epdf

Also

2073 - a few hints of our presence. Oct 13, 2006.

http://inkpi.blogspot.it/2006/10/2073-few-hints-of-our-presence.html

giovedì 13 luglio 2017

# s-brain: neuro-active areas during the real-time creation of funny stories

<< Unlike passive humor appreciation, the neural correlates of real-time humor creation have been unexplored. >> [!]

<< Greater comedic experience was associated with decreased activation in the striatum and medial prefrontal cortex (mPFC), but increased activation in temporal association regions (TMP).  Less experienced comedians manifested greater activation of mPFC, reflecting their deliberate search through TMP association space. Professionals, by contrast, tend to reap the fruits of their spontaneous associations with reduced reliance on top-down guided search. >>

Ori Amir, Irving Biederman. The Neural Correlates of Humor Creativity. Front. Hum. Neurosci., 25 Nov. 25, 2016 doi: 10.3389/fnhum.2016.00597.

http://journal.frontiersin.org/article/10.3389/fnhum.2016.00597

Michelle Boston. Researchers pinpoint the regions of the brain that spark during the telling of a funny story. Feb. 27, 2017.

https://m.medicalxpress.com/news/2017-02-regions-brain-funny-story.html

mercoledì 12 luglio 2017

# s-phys: more about retrocausality

<<  In a new paper (..) [AA] have lent new theoretical support for the argument that, if certain reasonable-sounding assumptions are made, then quantum theory must be retrocausal >>

<< retrocausality means that, when an experimenter chooses the measurement setting with which to measure a particle, that decision can influence the properties of that particle (or another particle) in the past, even before the experimenter made their choice. In other words, a decision made in the present can influence something in the past >>

<< "Speculatively, if there is retrocausality in the universe, then it might be the case that there are certain eras, perhaps near the big bang, in which there is not a definite arrow of causality. You might imagine that a signature of such an era might show up in cosmological data, such as the cosmic microwave background. However, this is very speculative, and I have no idea what signatures we might expect yet." >> Matthew S. Leifer.

<< The physicists don't have any experiments lined up to test retrocausality—but as the idea is more an interpretation of observations rather than making new observations, what's needed most may not be a test but more theoretical support >>

Lisa Zyga. Pysicists provide support for retrocausal quantum theory, in which the future influences the past. July 5,  2017.

https://m.phys.org/news/2017-07-physicists-retrocausal-quantum-theory-future.html

Matthew S. Leifer,  Matthew F. Pusey. Is a time symmetric interpretation of quantum theory possible without retrocausality?   Proc. Royal Soc. A. June  2017 Volume 473,  issue 2202 doi: 10.1098/rspa.2016.0607 Publ. Jun. 21, 2017.

http://rspa.royalsocietypublishing.org/content/473/2202/20160607

https://arxiv.org/abs/1607.07871