Biology

Transmediale digital arts: The internet’s impossible paradox

Genetics - сб, 2018-02-24 12:00
The internet poses an impossible paradox for digital artists: – the tech that delivers so much also filters out the context that allows art to really do its job
Категории: Biology

Compositional shifts in root-associated bacterial and archaeal microbiota track the plant life cycle in field-grown rice

PLOS Biology (new articles) - сб, 2018-02-24 00:00

by Joseph A. Edwards, Christian M. Santos-Medellín, Zachary S. Liechty, Bao Nguyen, Eugene Lurie, Shane Eason, Gregory Phillips, Venkatesan Sundaresan

Bacterial communities associated with roots impact the health and nutrition of the host plant. The dynamics of these microbial assemblies over the plant life cycle are, however, not well understood. Here, we use dense temporal sampling of 1,510 samples from root spatial compartments to characterize the bacterial and archaeal components of the root-associated microbiota of field grown rice (Oryza sativa) over the course of 3 consecutive growing seasons, as well as 2 sites in diverse geographic regions. The root microbiota was found to be highly dynamic during the vegetative phase of plant growth and then stabilized compositionally for the remainder of the life cycle. Bacterial and archaeal taxa conserved between field sites were defined as predictive features of rice plant age by modeling using a random forest approach. The age-prediction models revealed that drought-stressed plants have developmentally immature microbiota compared to unstressed plants. Further, by using genotypes with varying developmental rates, we show that shifts in the microbiome are correlated with rates of developmental transitions rather than age alone, such that different microbiota compositions reflect juvenile and adult life stages. These results suggest a model for successional dynamics of the root-associated microbiota over the plant life cycle.
Категории: Biology, Journals

Trigger warnings are taking over universities, but do they work?

Genetics - пт, 2018-02-23 18:45
Talk of trigger warnings and microaggressions are sweeping through university campuses, but some researchers question whether they have any psychological basis
Категории: Biology

Weird particle soup may have formed stars in the early universe

Genetics - пт, 2018-02-23 18:40
Pions are particles that usually decay very quickly. But right after the big bang, they could have made stars that last long enough for us to detect now
Категории: Biology

How you speak predicts if psychedelic therapy will help you

Genetics - пт, 2018-02-23 18:00
Psilocybin, a compound in magic mushrooms, may help treat depression in some people. Now speech analysis can indicate who would benefit the most
Категории: Biology

Almost every antidepressant headline you’ll read today is wrong

Genetics - пт, 2018-02-23 16:40
A review of the evidence on antidepressants has been hailed as the final word on these drugs, but questions remain for people with less severe depression
Категории: Biology

Green is the new black: Redesigning clothes to save the planet

Genetics - пт, 2018-02-23 14:00
The clothes on your back are responsible for huge amounts of pollution – but lab-grown fabrics and changes to our fashion habits can make a big difference
Категории: Biology

Feedback: Some cows are pessimists, just like us

Genetics - пт, 2018-02-23 14:00
A trick milk bottle reveals not all calves hold a positive mental attitude. Plus: the distance Vikings had to go before they had to go, remembering Sammy Jankis, and more
Категории: Biology

The tamed ape: were humans the first animal to be domesticated?

Genetics - пт, 2018-02-23 13:40
Deep inside our genome are bits of DNA we share only with animals such as dogs and cattle. Our self-domestication may have been a pivotal moment in making us human
Категории: Biology

We may be overdue a massive war, says a statistical analysis

Genetics - пт, 2018-02-23 13:12
Since the end of the second world war a “long peace” has prevailed around the world, but far from being a new era in history it could just be a statistical fluke
Категории: Biology

Eating fish as a child seems to protect you from hay fever

Genetics - пт, 2018-02-23 12:49
Infants who eat fish are less likely to develop hay fever later on, a finding that suggests changing diets have played a role in rising allergy rates
Категории: Biology

Ancient ‘dark-skinned’ Briton Cheddar Man find may not be true

Genetics - пт, 2018-02-23 12:02
The headline was that an ancient Briton from 10,000 years ago had dark skin, but the genetics of skin colour are so complex that we can’t be sure
Категории: Biology

Having children may add 11 years to a woman’s biological age

Genetics - пт, 2018-02-23 09:00
Having a baby seems to be linked to shorter caps on the ends of a woman’s chromosomes – a sign of ageing that has been linked to disease and a shorter lifespan
Категории: Biology

Effective polyploidy causes phenotypic delay and influences bacterial evolvability

PLOS Biology (new articles) - пт, 2018-02-23 00:00

by Lei Sun, Helen K. Alexander, Balazs Bogos, Daniel J. Kiviet, Martin Ackermann, Sebastian Bonhoeffer

Whether mutations in bacteria exhibit a noticeable delay before expressing their corresponding mutant phenotype was discussed intensively in the 1940s to 1950s, but the discussion eventually waned for lack of supportive evidence and perceived incompatibility with observed mutant distributions in fluctuation tests. Phenotypic delay in bacteria is widely assumed to be negligible, despite the lack of direct evidence. Here, we revisited the question using recombineering to introduce antibiotic resistance mutations into E. coli at defined time points and then tracking expression of the corresponding mutant phenotype over time. Contrary to previous assumptions, we found a substantial median phenotypic delay of three to four generations. We provided evidence that the primary source of this delay is multifork replication causing cells to be effectively polyploid, whereby wild-type gene copies transiently mask the phenotype of recessive mutant gene copies in the same cell. Using modeling and simulation methods, we explored the consequences of effective polyploidy for mutation rate estimation by fluctuation tests and sequencing-based methods. For recessive mutations, despite the substantial phenotypic delay, the per-copy or per-genome mutation rate is accurately estimated. However, the per-cell rate cannot be estimated by existing methods. Finally, with a mathematical model, we showed that effective polyploidy increases the frequency of costly recessive mutations in the standing genetic variation (SGV), and thus their potential contribution to evolutionary adaptation, while drastically reducing the chance that de novo recessive mutations can rescue populations facing a harsh environmental change such as antibiotic treatment. Overall, we have identified phenotypic delay and effective polyploidy as previously overlooked but essential components in bacterial evolvability, including antibiotic resistance evolution.
Категории: Biology, Journals

Reproducibility of preclinical animal research improves with heterogeneity of study samples

PLOS Biology (new articles) - пт, 2018-02-23 00:00

by Bernhard Voelkl, Lucile Vogt, Emily S. Sena, Hanno Würbel

Single-laboratory studies conducted under highly standardized conditions are the gold standard in preclinical animal research. Using simulations based on 440 preclinical studies across 13 different interventions in animal models of stroke, myocardial infarction, and breast cancer, we compared the accuracy of effect size estimates between single-laboratory and multi-laboratory study designs. Single-laboratory studies generally failed to predict effect size accurately, and larger sample sizes rendered effect size estimates even less accurate. By contrast, multi-laboratory designs including as few as 2 to 4 laboratories increased coverage probability by up to 42 percentage points without a need for larger sample sizes. These findings demonstrate that within-study standardization is a major cause of poor reproducibility. More representative study samples are required to improve the external validity and reproducibility of preclinical animal research and to prevent wasting animals and resources for inconclusive research.
Категории: Biology, Journals

Miniature personalised tumours could help you get the best chemo

Genetics - чт, 2018-02-22 21:00
Growing mini tumours in the lab from a patient’s own cells could help doctors discover the best way to treat each person, homing in on the right drugs to use
Категории: Biology

Neanderthals made the oldest cave art in the world

Genetics - чт, 2018-02-22 21:00
We weren’t the only ancient artists – the discovery of 66,700-year-old cave art show our Neanderthal cousins also liked to draw
Категории: Biology

Can you predict the future? Take our Oscars quiz to find out

Genetics - чт, 2018-02-22 19:40
Intelligence agencies have found that crowds of everyday people can forecast events with surprising accuracy. Now we’re running our own experiment
Категории: Biology

Why do firms like Uber and Citymapper keep reinventing buses?

Genetics - чт, 2018-02-22 19:17
Apps want to disrupt public transport by creating “innovative” services that look suspiciously like buses, but real-time data could make for a better ride
Категории: Biology

Bats spread Ebola because they’ve evolved not to fight viruses

Genetics - чт, 2018-02-22 19:00
Bats can carry viruses like Ebola and Marburg that are lethal for humans. This may be because, in order to fly, their bodies have given up on fighting such viruses
Категории: Biology