101 research outputs found
Global Diversity of Ascidiacea
The class Ascidiacea presents fundamental opportunities for research in the fields of development, evolution, ecology, natural products and more. This review provides a comprehensive overview of the current knowledge regarding the global biodiversity of the class Ascidiacea, focusing in their taxonomy, main regions of biodiversity, and distribution patterns. Based on analysis of the literature and the species registered in the online World Register of Marine Species, we assembled a list of 2815 described species. The highest number of species and families is found in the order Aplousobranchia. Didemnidae and Styelidae families have the highest number of species with more than 500 within each group. Sixty percent of described species are colonial. Species richness is highest in tropical regions, where colonial species predominate. In higher latitudes solitary species gradually contribute more to the total species richness. We emphasize the strong association between species richness and sampling efforts, and discuss the risks of invasive species. Our inventory is certainly incomplete as the ascidian fauna in many areas around the world is relatively poorly known, and many new species continue to be discovered and described each year
Intra-regional transportation of a tugboat fouling community between the ports of recife and natal, northeast Brazil
The LHCb upgrade I
The LHCb upgrade represents a major change of the experiment. The detectors have been almost completely renewed to allow running at an instantaneous luminosity five times larger than that of the previous running periods. Readout of all detectors into an all-software trigger is central to the new design, facilitating the reconstruction of events at the maximum LHC interaction rate, and their selection in real time. The experiment's tracking system has been completely upgraded with a new pixel vertex detector, a silicon tracker upstream of the dipole magnet and three scintillating fibre tracking stations downstream of the magnet. The whole photon detection system of the RICH detectors has been renewed and the readout electronics of the calorimeter and muon systems have been fully overhauled. The first stage of the all-software trigger is implemented on a GPU farm. The output of the trigger provides a combination of totally reconstructed physics objects, such as tracks and vertices, ready for final analysis, and of entire events which need further offline reprocessing. This scheme required a complete revision of the computing model and rewriting of the experiment's software
The Effect of Operating Modes on the Response of Ammonia Sensors Based on Tin Dioxide Films
Neural response to social rejection in children with early separation experiences.
Objective: Nonhuman and human studies have documented the adverse effects of early life stress (ELS) on emotion regulation and underlying neural circuitry. Less is known about how these experiences shape social processes and neural circuitry. In this study, we thus investigated how ELS affects children's perception of, and neural response to, negative social experiences in a social exclusion paradigm (Cyberball). Method: Twenty-five foster or adopted children with ELS (age 10.6 +/- 1.8 years, 13 male and 12 female) and 26 matched nonseparated controls (age 10.38 +/- 1.7 years, 12 male and 14 female) took part in a Cyberball paradigm during functional magnetic resonance imaging (fMRI). Results: During peer rejection, children with ELS reported significantly more feelings of exclusion and frustration than nonseparated controls. On the neural level, children with ELS showed reduced activation in the dorsal anterior cingulate cortex (dACC) and dorsolateral prefrontal cortex (dlPFC), and reduced connectivity between dlPFC-dACC, areas previously implicated in affect regulation. Conversely, children with ELS showed increased neural activation in brain regions involved in memory, arousal, and threat-related processing (middle temporal gyrus, thalamus, ventral tegmental area) relative to controls during social exclusion. The number of separation experiences before entering the permanent family predicted reductions in fronto-cingulate recruitment. The relationship between early separations and self-reported exclusion was mediated by dlPFC activity. Conclusion: The findings suggest that ELS leads to alterations in neural circuitry implicated in the regulation of socioemotional processes. This neural signature may underlie foster children's differential reactivity to rejection in everyday life and could increase risk for developing affective disorders
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