Zobrazení zdroje stránky Holgersenross8758

Circadian regulation has a pervasive influence upon plant development, physiology and metabolism, impacting upon components of fitness and traits of agricultural importance. Circadian regulation is inextricably connected to the responses of plants to their abiotic environments, from the cellular to whole plant scales. Here, we review the crosstalk that occurs between circadian regulation and responses to the abiotic environment from the intracellular scale through to naturally fluctuating environments. We examine the spatial crosstalk that forms part of plant circadian regulation, at the subcellular, tissue, organ and whole-plant scales. This includes a focus on chloroplast and mitochondrial signalling, alternative splicing, long-distance circadian signalling and circadian regulation within natural environments. We also consider mathematical models for plant circadian regulation, to suggest future areas for advancing understanding of roles for circadian regulation in plant responses to environmental cues.How the brain categorizes external stimuli in an experience-dependent, behaviorally relevant manner is a fundamental question. A new study reveals that mitral cells in the olfactory bulb of mice dynamically represent value- and category-related odor information in learned behavioral tasks.Effective motor control requires the real-time transmission of information between sensory organs and the motor system. With the powerful techniques that are now available, Drosophila neuroscientists are unravelling the topology of the neural circuits that carry this information in the fly at synaptic resolution.The pathogenesis of life-threatening infections caused by emerging fungal pathogens remains largely unexplored. A new study provides unprecedented evidence for the pivotal role of a new ricin-like protein toxin, named mucoricin, in causing organ necrosis and mortality in Mucorales infections.Water conservation played a role in the evolutionary adaptation of humans to hot, dry environments, but until now the extent of such biological adaptability was unknown. A new study compares great apes and humans to illuminate the complexities of water balance in humans and the factors that influence it.Microtubule attachments to kinetochores cause their deformation - a murky phenomenon known as intra-kinetochore stretching. A new study proposes that intra-kinetochore stretching is independent of microtubule-pulling forces and mediates efficient spindle assembly checkpoint silencing to prevent chromosomal instability.The ability to flower without strict daylength constraints has helped spread cultivation of crop plants to new locations. The generation of daylength-insensitive common bean accessions in central and South America involved the repeated selection of mutant alleles for a key transcription factor that suppresses long-day flowering.A new study investigates hunters' causal understandings of bow design and mechanics among the Hadza, one of the last remaining foraging populations. The results suggest that sophisticated technology can evolve without complete causal understanding.The molecular genetic dissection of Drosophila colour vision circuitry reveals converging pathways previously categorized as being chromatic versus achromatic. Amacrine-like Dm8 cells receive direct and indirect inputs with different spectral sensitivity tuning, thereby forming the second stage of colour-opponent processing.We rely on gaze to guide subsequent steps during walking, more so when the terrain ahead is more uncertain. New research shows that the increased visual exploration during walking as the terrain becomes more uncertain reflects our preference for accuracy over effort in step choice.We rapidly classify odors as pleasant or aversive, but the brain circuits underlying how odors motivate approach and avoidance responses are largely unknown. New research describes a direct path from the olfactory bulb to ventral striatum driving odor-mediated reward.In the recent study in Current Biology by Pei and colleagues1, we used two proxies - wing loading and specific lift - to reconstruct powered flight potential across the vaned feathered fossil pennaraptorans. The results recovered multiple origins of powered flight. We respectfully disagree with the criticism raised by Serrano and Chiappe2 that wing loading and specific lift, used in sequence, fail to discriminate between powered flight and gliding. We will explain this in reference to our original conservative approach.Feathered dinosaurs discovered during the last decades have illuminated the transition from land to air in these animals, underscoring a significant degree of experimentation in wing-assisted locomotion around the origin of birds. Such evolutionary experimentation led to lineages achieving either wing-assisted running, four-winged gliding, or membrane-winged gliding. Birds are widely accepted as the only dinosaur lineage that achieved powered flight, a key innovation for their evolutionary success. However, in a recent paper in Current Biology, Pei and colleagues1 disputed this view. They concluded that three other lineages of paravian dinosaurs (those more closely related to birds than to oviraptorosaurs) - Unenlagiinae, Microraptorinae and Anchiornithinae - could have evolved powered flight independently. While we praise the detailed phylogenetic framework of Pei and colleagues1 and welcome a new attempt to understand the onset of flight in dinosaurs, we here expose a set of arguments that significantly weaken their evidence supporting a multiple origin of powered flight. [https://www.selleckchem.com/products/17-AAG(Geldanamycin).html learn more] Specifically, we maintain that the two proxies used by Pei and colleagues1 to assess powered flight potential in non-avian paravians - wing loading and specific lift - fail to discriminate between powered flight (thrust generated by flapping) and passive flight (gliding).In 2016, the research ice-breaker Polarstern surveyed the submerged peaks of the permanently ice-covered Langseth Ridge, a tectonic feature comprising the Karasik seamount and two deeper seamount peaks, abutting the Gakkel ultra-slow spreading ridge (87°N 62°E to 85.5°N 57.4°E)1. A towed marine camera sled and a hybrid remotely operated vehicle revealed these peaks to be covered by a dense demosponge community, at first glance reminiscent of North Atlantic Geodia grounds (sensu2). Sponges were observed on top of a thick layer of spicule mat (Figure 1 and Video S1), intermixed with underlying layers of empty siboglinid tubes and bivalve shells, a substrate covering almost the entire seafloor. We observed trails of densely interwoven spicules connected directly to the underside or lower flanks of sponge individuals (Figure 1), suggesting these trails are traces of motile sponges. This is the first time abundant sponge trails have been observed in situ and attributed to sponge mobility. Given the low primary production in this permanently ice-covered region, these trails may relate to feeding behavior and/or a strategy for dispersal of juveniles. Such trails may remain visible for long periods given the regionally low sedimentation rates.Manon de Visser and colleagues introduce the rarest and smallest wild pig species, the pygmy hog (Porcula salvania).Interview with Audrey Dussutour, who uses slime molds and ant colonies to study collective behavior and cognition at the Center for Integrative Biology in Toulouse.Obituary of visual neurobiologist Michael Land, whose studies pioneered the fields of animal and human vision, optics and behavioural psychology.Adenosine-to-inosine editing is catalyzed by ADAR1 at thousands of sites transcriptome-wide. Despite intense interest in ADAR1 from physiological, bioengineering, and therapeutic perspectives, the rules of ADAR1 substrate selection are poorly understood. Here, we used large-scale systematic probing of ∼2,000 synthetic constructs to explore the structure and sequence context determining editability. We uncover two structural layers determining the formation and propagation of A-to-I editing, independent of sequence. First, editing is robustly induced at fixed intervals of 35 bp upstream and 30 bp downstream of structural disruptions. Second, editing is symmetrically introduced on opposite sites on a double-stranded structure. Our findings suggest a recursive model for RNA editing, whereby the structural alteration induced by the editing at one site iteratively gives rise to the formation of an additional editing site at a fixed periodicity, serving as a basis for the propagation of editing along and across both strands of double-stranded RNA structures.How are E3 ubiquitin ligases configured to match substrate quaternary structures? Here, by studying the yeast GID complex (mutation of which causes deficiency in glucose-induced degradation of gluconeogenic enzymes), we discover supramolecular chelate assembly as an E3 ligase strategy for targeting an oligomeric substrate. Cryoelectron microscopy (cryo-EM) structures show that, to bind the tetrameric substrate fructose-1,6-bisphosphatase (Fbp1), two minimally functional GID E3s assemble into the 20-protein Chelator-GIDSR4, which resembles an organometallic supramolecular chelate. The Chelator-GIDSR4 assembly avidly binds multiple Fbp1 degrons so that multiple Fbp1 protomers are simultaneously ubiquitylated at lysines near the allosteric and substrate binding sites. Importantly, key structural and biochemical features, including capacity for supramolecular assembly, are preserved in the human ortholog, the CTLH E3. Based on our integrative structural, biochemical, and cell biological data, we propose that higher-order E3 ligase assembly generally enables multipronged targeting, capable of simultaneously incapacitating multiple protomers and functionalities of oligomeric substrates.<br /><br /> Thoracentesis and tube thoracostomy are common procedures with bleeding risks, but existing guidelines may be overly conservative. We reviewed the evidence on the safety of thoracentesis and tube thoracostomy in patients with uncorrected coagulopathy.<br /><br /> Is it safe to perform thoracentesis and tube thoracostomy in patients with uncorrected coagulopathy?<br /><br /> This systematic review was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analysis guidelines. PubMed and Embase were searched from inception through December 31, 2019. Included studies involved patients with uncorrected coagulopathy because of disease (eg, thrombocytopenia, liver cirrhosis, kidney failure) or drugs (eg, antiplatelets, anticoagulants). Relevant outcomes were major bleeding and mortality.<br /><br /> Eighteen studies (5,134 procedures) were included. Using random-effects meta-analysis, the pooled major bleeding and mortality rate was 0 (95%CI, 0%-1%). No publication bias was found. Excluding six studies that were in abstract form, meta-analysis of the remaining 12 full articles showed that the pooled major bleeding and mortality rate also was 0 (95%CI, 0%-2%). Subgroup analysis performed for patients with uncorrected coagulopathy resulting from disease or drugs showed similar results.<br /><br /> Among patients with uncorrected coagulopathy who underwent thoracentesis or tube thoracostomy, major bleeding and mortality complications were uncommon. Our results suggest that in appropriately selected patients, thoracentesis or tube thoracostomy can be performed safely.<br /><br /> PROSPERO; No. CRD42020152226; URL www.crd.york.ac.uk/prospero/.<br /><br />PROSPERO; No. CRD42020152226; URL www.crd.york.ac.uk/prospero/.