390 research outputs found
Arctic Ocean Microbial Community Structure before and after the 2007 Record Sea Ice Minimum
Increasing global temperatures are having a profound impact in the Arctic, including the dramatic loss of multiyear sea ice in 2007 that has continued to the present. The majority of life in the Arctic is microbial and the consequences of climate-mediated changes on microbial marine food webs, which are responsible for biogeochemical cycling and support higher trophic levels, are unknown. We examined microbial communities over time by using high-throughput sequencing of microbial DNA collected between 2003 and 2010 from the subsurface chlorophyll maximum (SCM) layer of the Beaufort Sea (Canadian Arctic). We found that overall this layer has freshened and concentrations of nitrate, the limiting nutrient for photosynthetic production in Arctic seas, have decreased. We compared microbial communities from before and after the record September 2007 sea ice minimum and detected significant differences in communities from all three domains of life. In particular, there were significant changes in species composition of Eukarya, with ciliates becoming more common and heterotrophic marine stramenopiles (MASTs) accounting for a smaller proportion of sequences retrieved after 2007. Within the Archaea, Marine Group I Thaumarchaeota, which earlier represented up to 60% of the Archaea sequences in this layer, have declined to <10%. Bacterial communities overall were less diverse after 2007, with a significant decrease of the Bacteroidetes. These significant shifts suggest that the microbial food webs are sensitive to physical oceanographic changes such as those occurring in the Canadian Arctic over the past decade
Empirical Comparisons of Different Statistical Models To Identify and Validate Kernel Row Number-Associated Variants from Structured Multi-parent Mapping Populations of Maize
Advances in next generation sequencing technologies and statistical approaches enable genomewide dissection of phenotypic traits via genome-wide association studies (GWAS). Although multiple statistical approaches for conducting GWAS are available, the power and cross-validation rates of many approaches have been mostly tested using simulated data. Empirical comparisons of single variant (SV) and multi-variant (MV) GWAS approaches have not been conducted to test if a single approach or a combination of SV and MV is effective, through identification and cross-validation of trait-associated loci. In this study, kernel row number (KRN) data were collected from a set of 6,230 entries derived from the Nested Association Mapping (NAM) population and related populations. Three different types of GWAS analyses were performed: 1) single-variant (SV), 2) stepwise regression (STR) and 3) a Bayesian-based multi-variant (BMV) model. Using SV, STR, and BMV models, 257, 300, and 442 KRN-associated variants (KAVs) were identified in the initial GWAS analyses. Of these, 231 KAVs were subjected to genetic validation using three unrelated populations that were not included in the initial GWAS. Genetic validation results suggest that the three GWAS approaches are complementary. Interestingly, KAVs in low recombination regions were more likely to exhibit associations in independent populations than KAVs in recombinationally active regions, probably as a consequence of linkage disequilibrium. The KAVs identified in this study have the potential to enhance our understanding of the genetic basis of ear development
Dynamics of quantum quenching for BCS-BEC systems in the shallow BEC regime
The problem of coupled Fermi-Bose mixtures of an ultracold gas near a narrow
Feshbach resonance is approached through the time-dependent and complex
Ginzburg-Landau (TDGL) theory. The dynamical system is constructed using
Ginzburg-Landau-Abrikosov-Gor'kov (GLAG) path integral methods with the single
mode approximation for the composite Bosons, and the equilibrium states are
obtained in the BEC regime for adiabatic variations of the Feshbach detuning
along the stationary solutions of the dynamical system. Investigations into the
rich superfluid dynamics of this system in the shallow BEC regime yields the
onset of multiple interference patterns in the dynamics as the system is
quenched from the deep-BEC regime. This results in a partial collapse and
revival of the coherent matter wave field of the BEC, whose temporal profile is
reported.Comment: 24 pages, 7 figures. Submitted to European Journal of Physics Plu
Animal Ca2+ release-activated Ca2+ (CRAC) channels appear to be homologous to and derived from the ubiquitous cation diffusion facilitators
<p>Abstract</p> <p>Background</p> <p>Antigen stimulation of immune cells triggers Ca<sup>2+ </sup>entry through Ca<sup>2+ </sup>release-activated Ca<sup>2+ </sup>(CRAC) channels, promoting an immune response to pathogens. Defects in a CRAC (Orai) channel in humans gives rise to the hereditary Severe Combined Immune Deficiency (SCID) syndrome. We here report results that define the evolutionary relationship of the CRAC channel proteins of animals, and the ubiquitous Cation Diffusion Facilitator (CDF) carrier proteins.</p> <p>Findings</p> <p>CDF antiporters derived from a primordial 2 transmembrane spanner (TMS) hairpin structure by intragenic triplication to yield 6 TMS proteins. Four programs (IC/GAP, GGSEARCH, HMMER and SAM) were evaluated for identifying sequence similarity and establishing homology using statistical means. Overall, the order of sensitivity (similarity detection) was IC/GAP = GGSEARCH > HMMER > SAM, but the use of all four programs was superior to the use of any two or three of them. Members of the CDF family appeared to be homologous to members of the 4 TMS Orai channel proteins.</p> <p>Conclusions</p> <p>CRAC channels derived from CDF carriers by loss of the first two TMSs of the latter. Based on statistical analyses with multiple programs, TMSs 3-6 in CDF carriers are homologous to TMSs 1-4 in CRAC channels, and the former was the precursor of the latter. This is an unusual example of how a functionally and structurally more complex protein may have predated a simpler one.</p
Adverse Childhood Experiences: Roads to Recovery
THE ALL-PARTY PARLIAMENTARY GROUP AND THE WORKING GROUP The Working Group that produced this Report is a sub-group of the All-Party Parliamentary Group on a Fit and Healthy Childhood. The purpose of the APPG is to promote evidence-based discussion and produce reports on all aspect of childhood health and wellbeing including obesity, to inform policy decisions and public debate relating to childhood; and to enable communications between interested parties and relevant parliamentarians. Group details are recorded on the Parliamentary website at: https://publications.parliament.uk/pa/cm/cmallparty/190911/fit-and-healthychildhood.htm The Working Group is chaired by Helen Clark, a member of the APPG secretariat. Working Group members are volunteers from the APPG membership with an interest in this subject area. Those that have contributed to the work of the Working Group are listed on the previous page. The Report is divided into themed subject chapters with recommendations that we hope will influence active Government policy
The Solute Carrier Families Have a Remarkably Long Evolutionary History with the Majority of the Human Families Present before Divergence of Bilaterian Species
The Solute Carriers (SLCs) are membrane proteins that regulate transport of many types of substances over the cell membrane. The SLCs are found in at least 46 gene families in the human genome. Here, we performed the first evolutionary analysis of the entire SLC family based on whole genome sequences. We systematically mined and analyzed the genomes of 17 species to identify SLC genes. In all, we identified 4,813 SLC sequences in these genomes, and we delineated the evolutionary history of each of the subgroups. Moreover, we also identified ten new human sequences not previously classified as SLCs, which most likely belong to the SLC family. We found that 43 of the 46 SLC families found in Homo sapiens were also found in Caenorhabditis elegans, whereas 42 of them were also found in insects. Mammals have a higher number of SLC genes in most families, perhaps reflecting important roles for these in central nervous system functions. This study provides a systematic analysis of the evolutionary history of the SLC families in Eukaryotes showing that the SLC superfamily is ancient with multiple branches that were present before early divergence of Bilateria. The results provide foundation for overall classification of SLC genes and are valuable for annotation and prediction of substrates for the many SLCs that have not been tested in experimental transport assays
The Sorcerer II Global Ocean Sampling Expedition: Expanding the Universe of Protein Families
Metagenomics projects based on shotgun sequencing of populations of micro-organisms yield insight into protein families. We used sequence similarity clustering to explore proteins with a comprehensive dataset consisting of sequences from available databases together with 6.12 million proteins predicted from an assembly of 7.7 million Global Ocean Sampling (GOS) sequences. The GOS dataset covers nearly all known prokaryotic protein families. A total of 3,995 medium- and large-sized clusters consisting of only GOS sequences are identified, out of which 1,700 have no detectable homology to known families. The GOS-only clusters contain a higher than expected proportion of sequences of viral origin, thus reflecting a poor sampling of viral diversity until now. Protein domain distributions in the GOS dataset and current protein databases show distinct biases. Several protein domains that were previously categorized as kingdom specific are shown to have GOS examples in other kingdoms. About 6,000 sequences (ORFans) from the literature that heretofore lacked similarity to known proteins have matches in the GOS data. The GOS dataset is also used to improve remote homology detection. Overall, besides nearly doubling the number of current proteins, the predicted GOS proteins also add a great deal of diversity to known protein families and shed light on their evolution. These observations are illustrated using several protein families, including phosphatases, proteases, ultraviolet-irradiation DNA damage repair enzymes, glutamine synthetase, and RuBisCO. The diversity added by GOS data has implications for choosing targets for experimental structure characterization as part of structural genomics efforts. Our analysis indicates that new families are being discovered at a rate that is linear or almost linear with the addition of new sequences, implying that we are still far from discovering all protein families in nature
Fair Play For Girls
This report highlights the urgent need for equitable opportunities for girls in football. The report endorsed by leading figures in the football community and backed by the UK Government, underscores the importance of addressing gender disparities in sports provision and support
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