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Ants build a medieval ‘torture rack’ to catch grasshoppers

Genetically modified organisms (GMO) - Tue, 2018-04-24 11:00
A species of tropical ant builds traps on tree trunks that allow them to catch prey almost fifty times their size, by biting their legs and spread-eagling them on the tree surface
Categories: Science and society

We need hope, not eulogies, for the Great Barrier Reef

Genetics - Tue, 2018-04-24 11:00
Writing obituaries for the world’s greatest coral reef is attention-grabbing but scientifically wrong and ethically irresponsible
Categories: Biology

Ants build a medieval ‘torture rack’ to catch grasshoppers

Genetics - Tue, 2018-04-24 11:00
A species of tropical ant builds traps on tree trunks that allow them to catch prey almost fifty times their size, by biting their legs and spread-eagling them on the tree surface
Categories: Biology

We need hope, not eulogies, for the Great Barrier Reef

HIV and AIDS - Tue, 2018-04-24 11:00
Writing obituaries for the world’s greatest coral reef is attention-grabbing but scientifically wrong and ethically irresponsible

Ants build a medieval ‘torture rack’ to catch grasshoppers

HIV and AIDS - Tue, 2018-04-24 11:00
A species of tropical ant builds traps on tree trunks that allow them to catch prey almost fifty times their size, by biting their legs and spread-eagling them on the tree surface

This big cat’s seafood snack is an endangered turtle

Genetically modified organisms (GMO) - Tue, 2018-04-24 09:00
Thousands of sea turtles lay eggs on Tortuguero beach in Costa Rica every year. The annual ritual has become a feeding frenzy for jaguars
Categories: Science and society

This big cat’s seafood snack is an endangered turtle

Genetics - Tue, 2018-04-24 09:00
Thousands of sea turtles lay eggs on Tortuguero beach in Costa Rica every year. The annual ritual has become a feeding frenzy for jaguars
Categories: Biology

Dissecting the null model for biological invasions: A meta-analysis of the propagule pressure effect

PLOS Biology (new articles) - Mon, 2018-04-23 23:00

by Phillip Cassey, Steven Delean, Julie L. Lockwood, Jason Sadowski, Tim M. Blackburn

A consistent determinant of the establishment success of alien species appears to be the number of individuals that are introduced to found a population (propagule pressure), yet variation in the form of this relationship has been largely unexplored. Here, we present the first quantitative systematic review of this form, using Bayesian meta-analytical methods. The relationship between propagule pressure and establishment success has been evaluated for a broad range of taxa and life histories, including invertebrates, herbaceous plants and long-lived trees, and terrestrial and aquatic vertebrates. We found a positive mean effect of propagule pressure on establishment success to be a feature of every hypothesis we tested. However, establishment success most critically depended on propagule pressures in the range of 10–100 individuals. Heterogeneity in effect size was associated primarily with different analytical approaches, with some evidence of larger effect sizes in animal rather than plant introductions. Conversely, no variation was accounted for in any analysis by the scale of study (field to global) or methodology (observational, experimental, or proxy) used. Our analyses reveal remarkable consistency in the form of the relationship between propagule pressure and alien population establishment success.
Categories: Biology, Journals

In vivo clonal analysis reveals spatiotemporal regulation of thalamic nucleogenesis

PLOS Biology (new articles) - Mon, 2018-04-23 23:00

by Samuel Z. H. Wong, Earl Parker Scott, Wenhui Mu, Xize Guo, Ella Borgenheimer, Madeline Freeman, Guo-li Ming, Qing-Feng Wu, Hongjun Song, Yasushi Nakagawa

The thalamus, a crucial regulator of cortical functions, is composed of many nuclei arranged in a spatially complex pattern. Thalamic neurogenesis occurs over a short period during mammalian embryonic development. These features have hampered the effort to understand how regionalization, cell divisions, and fate specification are coordinated and produce a wide array of nuclei that exhibit distinct patterns of gene expression and functions. Here, we performed in vivo clonal analysis to track the divisions of individual progenitor cells and spatial allocation of their progeny in the developing mouse thalamus. Quantitative analysis of clone compositions revealed evidence for sequential generation of distinct sets of thalamic nuclei based on the location of the founder progenitor cells. Furthermore, we identified intermediate progenitor cells that produced neurons populating more than one thalamic nuclei, indicating a prolonged specification of nuclear fate. Our study reveals an organizational principle that governs the spatial and temporal progression of cell divisions and fate specification and provides a framework for studying cellular heterogeneity and connectivity in the mammalian thalamus.
Categories: Biology, Journals

In vivo insertion pool sequencing identifies virulence factors in a complex fungal–host interaction

PLOS Biology (new articles) - Mon, 2018-04-23 23:00

by Simon Uhse, Florian G. Pflug, Alexandra Stirnberg, Klaus Ehrlinger, Arndt von Haeseler, Armin Djamei

Large-scale insertional mutagenesis screens can be powerful genome-wide tools if they are streamlined with efficient downstream analysis, which is a serious bottleneck in complex biological systems. A major impediment to the success of next-generation sequencing (NGS)-based screens for virulence factors is that the genetic material of pathogens is often underrepresented within the eukaryotic host, making detection extremely challenging. We therefore established insertion Pool-Sequencing (iPool-Seq) on maize infected with the biotrophic fungus U. maydis. iPool-Seq features tagmentation, unique molecular barcodes, and affinity purification of pathogen insertion mutant DNA from in vivo-infected tissues. In a proof of concept using iPool-Seq, we identified 28 virulence factors, including 23 that were previously uncharacterized, from an initial pool of 195 candidate effector mutants. Because of its sensitivity and quantitative nature, iPool-Seq can be applied to any insertional mutagenesis library and is especially suitable for genetically complex setups like pooled infections of eukaryotic hosts.
Categories: Biology, Journals

How measurement science can improve confidence in research results

PLOS Biology (new articles) - Mon, 2018-04-23 23:00

by Anne L. Plant, Chandler A. Becker, Robert J. Hanisch, Ronald F. Boisvert, Antonio M. Possolo, John T. Elliott

The current push for rigor and reproducibility is driven by a desire for confidence in research results. Here, we suggest a framework for a systematic process, based on consensus principles of measurement science, to guide researchers and reviewers in assessing, documenting, and mitigating the sources of uncertainty in a study. All study results have associated ambiguities that are not always clarified by simply establishing reproducibility. By explicitly considering sources of uncertainty, noting aspects of the experimental system that are difficult to characterize quantitatively, and proposing alternative interpretations, the researcher provides information that enhances comparability and reproducibility.
Categories: Biology, Journals

The neural system of metacognition accompanying decision-making in the prefrontal cortex

PLOS Biology (new articles) - Mon, 2018-04-23 23:00

by Lirong Qiu, Jie Su, Yinmei Ni, Yang Bai, Xuesong Zhang, Xiaoli Li, Xiaohong Wan

Decision-making is usually accompanied by metacognition, through which a decision maker monitors uncertainty regarding a decision and may then consequently revise the decision. These decisional metacognitive processes can occur prior to or in the absence of feedback. However, the neural mechanisms of metacognition remain controversial. One theory proposes an independent neural system for metacognition in the prefrontal cortex (PFC); the other, that metacognitive processes coincide and overlap with the systems used for the decision-making process per se. In this study, we devised a novel “decision–redecision” paradigm to investigate the neural metacognitive processes involved in redecision as compared to the initial decision-making process. The participants underwent a perceptual decision-making task and a rule-based decision-making task during functional magnetic resonance imaging (fMRI). We found that the anterior PFC, including the dorsal anterior cingulate cortex (dACC) and lateral frontopolar cortex (lFPC), were more extensively activated after the initial decision. The dACC activity in redecision positively scaled with decisional uncertainty and correlated with individual metacognitive uncertainty monitoring abilities—commonly occurring in both tasks—indicating that the dACC was specifically involved in decision uncertainty monitoring. In contrast, the lFPC activity seen in redecision processing was scaled with decision uncertainty reduction and correlated with individual accuracy changes—positively in the rule-based decision-making task and negatively in the perceptual decision-making task. Our results show that the lFPC was specifically involved in metacognitive control of decision adjustment and was subject to different control demands of the tasks. Therefore, our findings support that a separate neural system in the PFC is essentially involved in metacognition and further, that functions of the PFC in metacognition are dissociable.
Categories: Biology, Journals

Why the hockey stick graph will always be climate science’s icon

Genetically modified organisms (GMO) - Mon, 2018-04-23 19:25
Two decades after it was first published, the chart linking carbon emissions and global warming is as relevant as ever, says Olive Heffernan
Categories: Science and society

Why the hockey stick graph will always be climate science’s icon

Genetics - Mon, 2018-04-23 19:25
Two decades after it was first published, the chart linking carbon emissions and global warming is as relevant as ever, says Olive Heffernan
Categories: Biology

Why the hockey stick graph will always be climate science’s icon

HIV and AIDS - Mon, 2018-04-23 19:25
Two decades after it was first published, the chart linking carbon emissions and global warming is as relevant as ever, says Olive Heffernan

Oxygen may have helped complex life arise a billion years early

Genetics - Mon, 2018-04-23 18:00
Earth’s air suddenly got a lot more oxygen around 1.6 billion years ago and that could have triggered the evolution of large multicellular organisms
Categories: Biology

Oxygen may have helped complex life arise a billion years early

HIV and AIDS - Mon, 2018-04-23 18:00
Earth’s air suddenly got a lot more oxygen around 1.6 billion years ago and that could have triggered the evolution of large multicellular organisms

Oxygen may have helped complex life arise a billion years early

Genetically modified organisms (GMO) - Mon, 2018-04-23 18:00
Earth’s air suddenly got a lot more oxygen around 1.6 billion years ago and that could have triggered the evolution of large multicellular organisms
Categories: Science and society

Quantum time: Is this where the flow of existence comes from?

Genetics - Mon, 2018-04-23 18:00
Why we perceive the passage of time is one of the biggest mysteries of physics. Now we could have found its source – in our most potent theory of reality
Categories: Biology

Quantum time: Is this where the flow of existence comes from?

Genetically modified organisms (GMO) - Mon, 2018-04-23 18:00
Why we perceive the passage of time is one of the biggest mysteries of physics. Now we could have found its source – in our most potent theory of reality
Categories: Science and society