6,128 research outputs found
The Glanville fritillary genome retains an ancient karyotype and reveals selective chromosomal fusions in Lepidoptera
Previous studies have reported that chromosome synteny in Lepidoptera has been well conserved, yet the number of haploid chromosomes varies widely from 5 to 223. Here we report the genome (393 Mb) of the Glanville fritillary butterfly (Melitaea cinxia; Nymphalidae), a widely recognized model species in metapopulation biology and eco-evolutionary research, which has the putative ancestral karyotype of n=31. Using a phylogenetic analyses of Nymphalidae and of other Lepidoptera, combined with orthologue-level comparisons of chromosomes, we conclude that the ancestral lepidopteran karyotype has been n=31 for at least 140 My. We show that fusion chromosomes have retained the ancestral chromosome segments and very few rearrangements have occurred across the fusion sites. The same, shortest ancestral chromosomes have independently participated in fusion events in species with smaller karyotypes. The short chromosomes have higher rearrangement rate than long ones. These characteristics highlight distinctive features of the evolutionary dynamics of butterflies and moths.Marie Curie International Fellowship (PIOF-GA-2011-303312
How Southwest Florida Prepares for its 2050 Health Care Workforce by Identifying and Creating Educational Programs: Needs, Demand, and Strategy
There is a concern about having enough healthcare providers in the next 30 years due to changing demographics and rapid population growth in Southwest Florida. The study objective is to determine the health care needs of Southwest Florida and the type of health care providers required, and then how to best provide educational programs to ensure there are the professionals in future years to meet the needs. The research will explore how the educational system as a critical component in the preparation of the region\u27s workforce can proactively address the anticipated programmatic gaps in achieving the projected needs of the community. Health care and education nationally and within the state of Florida are evolving and moving in new directions. It is important to explore how education and health care needs will intersect to meet the needs of a future population. The study is focused on Southwest Florida; however, the research addresses the national economic trends of health care since the migration of workers from state to state influences the local economy
Constraining the properties of neutron star crusts with the transient low-mass X-ray binary Aql X-1
Aql X-1 is a prolific transient neutron star low-mass X-ray binary that
exhibits an accretion outburst approximately once every year. Whether the
thermal X-rays detected in intervening quiescent episodes are the result of
cooling of the neutron star or due to continued low-level accretion remains
unclear. In this work we use Swift data obtained after the long and bright 2011
and 2013 outbursts, as well as the short and faint 2015 outburst, to
investigate the hypothesis that cooling of the accretion-heated neutron star
crust dominates the quiescent thermal emission in Aql X-1. We demonstrate that
the X-ray light curves and measured neutron star surface temperatures are
consistent with the expectations of the crust cooling paradigm. By using a
thermal evolution code, we find that ~1.2-3.2 MeV/nucleon of shallow heat
release describes the observational data well, depending on the assumed
mass-accretion rate and temperature of the stellar core. We find no evidence
for varying strengths of this shallow heating after different outbursts, but
this could be due to limitations of the data. We argue that monitoring Aql X-1
for up to ~1 year after future outbursts can be a powerful tool to break model
degeneracies and solve open questions about the magnitude, depth and origin of
shallow heating in neutron star crusts.Comment: 14 pages, 5 figures, 3 tables, accepted to MNRA
On p-adic lattices and Grassmannians
It is well-known that the coset spaces G(k((z)))/G(k[[z]]), for a reductive
group G over a field k, carry the geometric structure of an inductive limit of
projective k-schemes. This k-ind-scheme is known as the affine Grassmannian for
G. From the point of view of number theory it would be interesting to obtain an
analogous geometric interpretation of quotients of the form
G(W(k)[1/p])/G(W(k)), where p is a rational prime, W denotes the ring scheme of
p-typical Witt vectors, k is a perfect field of characteristic p and G is a
reductive group scheme over W(k). The present paper is an attempt to describe
which constructions carry over from the function field case to the p-adic case,
more precisely to the situation of the p-adic affine Grassmannian for the
special linear group G=SL_n. We start with a description of the R-valued points
of the p-adic affine Grassmannian for SL_n in terms of lattices over W(R),
where R is a perfect k-algebra. In order to obtain a link with geometry we
further construct projective k-subvarieties of the multigraded Hilbert scheme
which map equivariantly to the p-adic affine Grassmannian. The images of these
morphisms play the role of Schubert varieties in the p-adic setting. Further,
for any reduced k-algebra R these morphisms induce bijective maps between the
sets of R-valued points of the respective open orbits in the multigraded
Hilbert scheme and the corresponding Schubert cells of the p-adic affine
Grassmannian for SL_n.Comment: 36 pages. This is a thorough revision, in the form accepted by Math.
Zeitschrift, of the previously published preprint "On p-adic loop groups and
Grassmannians
Sequence-structure-function relations of the mosquito leucine-rich repeat immune proteins.
<p>Abstract</p> <p>Background</p> <p>The discovery and characterisation of factors governing innate immune responses in insects has driven the elucidation of many immune system components in mammals and other organisms. Focusing on the immune system responses of the malaria mosquito, <it>Anopheles gambiae</it>, has uncovered an array of components and mechanisms involved in defence against pathogen infections. Two of these immune factors are LRIM1 and APL1C, which are leucine-rich repeat (LRR) containing proteins that activate complement-like defence responses against malaria parasites. In addition to their LRR domains, these leucine-rich repeat immune (LRIM) proteins share several structural features including signal peptides, patterns of cysteine residues, and coiled-coil domains.</p> <p>Results</p> <p>The identification and characterisation of genes related to <it>LRIM1 </it>and <it>APL1C </it>revealed putatively novel innate immune factors and furthered the understanding of their likely molecular functions. Genomic scans using the shared features of <it>LRIM1 </it>and <it>APL1C </it>identified more than 20 <it>LRIM</it>-like genes exhibiting all or most of their sequence features in each of three disease-vector mosquitoes with sequenced genomes: <it>An. gambiae</it>, <it>Aedes aegypti</it>, and <it>Culex quinquefasciatus</it>. Comparative sequence analyses revealed that this family of mosquito <it>LRIM</it>-like genes is characterised by a variable number of 6 to 14 LRRs of different lengths. The "Long" LRIM subfamily, with 10 or more LRRs, and the "Short" LRIMs, with 6 or 7 LRRs, also share the signal peptide, cysteine residue patterning, and coiled-coil sequence features of LRIM1 and APL1C. The "TM" LRIMs have a predicted C-terminal transmembrane region, and the "Coil-less" LRIMs exhibit the characteristic LRIM sequence signatures but lack the C-terminal coiled-coil domains.</p> <p>Conclusions</p> <p>The evolutionary plasticity of the LRIM LRR domains may provide templates for diverse recognition properties, while their coiled-coil domains could be involved in the formation of LRIM protein complexes or mediate interactions with other immune proteins. The conserved LRIM cysteine residue patterns are likely to be important for structural fold stability and the formation of protein complexes. These sequence-structure-function relations of mosquito LRIMs will serve to guide the experimental elucidation of their molecular roles in mosquito immunity.</p
Report on status and trends of water quality and ecosystem health in the Great Barrier Reef World Heritage Area
Contributors: Rob Coles, Steve Delean, Miles Furnas, Len McKenzie, Munro Mortimer, Jochen Muller, Andrew Negri, Hugh Sweatman and Angus Thompson
Summary Visualizations of Gene Ontology Terms With GO-Figure!
The Gene Ontology (GO) is a cornerstone of functional genomics research that drives discoveries through knowledge-informed computational analysis of biological data from large-scale assays. Key to this success is how the GO can be used to support hypotheses or conclusions about the biology or evolution of a study system by identifying annotated functions that are overrepresented in subsets of genes of interest. Graphical visualizations of such GO term enrichment results are critical to aid interpretation and avoid biases by presenting researchers with intuitive visual data summaries. Amongst current visualization tools and resources there is a lack of standalone open-source software solutions that facilitate explorations of key features of multiple lists of GO terms. To address this we developed GO-Figure!, an open-source Python software for producing user-customisable semantic similarity scatterplots of redundancy-reduced GO term lists. The lists are simplified by grouping together terms with similar functions using their quantified information contents and semantic similarities, with user-control over grouping thresholds. Representatives are then selected for plotting in two-dimensional semantic space where similar terms are placed closer to each other on the scatterplot, with an array of user-customisable graphical attributes. GO-Figure! offers a simple solution for command-line plotting of informative summary visualizations of lists of GO terms, designed to support exploratory data analyses and dataset comparisons
Extention of Finite Solvable Torsors over a Curve
Let be a discrete valuation ring with fraction field and with
algebraically closed residue field of positive characteristic . Let be a
smooth fibered surface over with geometrically connected fibers endowed
with a section . Let be a finite solvable -group scheme and
assume that either or has a normal series of length 2. We prove
that every quotient pointed -torsor over the generic fiber of
can be extended to a torsor over after eventually extending scalars and
after eventually blowing up at a closed subscheme of its special fiber
.Comment: 16 page
A remarkably stable TipE gene cluster: evolution of insect Para sodium channel auxiliary subunits
<p>Abstract</p> <p>Background</p> <p>First identified in fruit flies with temperature-sensitive paralysis phenotypes, the <it>Drosophila melanogaster TipE </it>locus encodes four voltage-gated sodium (Na<sub>V</sub>) channel auxiliary subunits. This cluster of <it>TipE</it>-like genes on chromosome 3L, and a fifth family member on chromosome 3R, are important for the optional expression and functionality of the Para Na<sub>V </sub>channel but appear quite distinct from auxiliary subunits in vertebrates. Here, we exploited available arthropod genomic resources to trace the origin of <it>TipE</it>-like genes by mapping their evolutionary histories and examining their genomic architectures.</p> <p>Results</p> <p>We identified a remarkably conserved synteny block of <it>TipE</it>-like orthologues with well-maintained local gene arrangements from 21 insect species. Homologues in the water flea, <it>Daphnia pulex</it>, suggest an ancestral pancrustacean repertoire of four <it>TipE</it>-like genes; a subsequent gene duplication may have generated functional redundancy allowing gene losses in the silk moth and mosquitoes. Intronic nesting of the insect <it>TipE </it>gene cluster probably occurred following the divergence from crustaceans, but in the flour beetle and silk moth genomes the clusters apparently escaped from nesting. Across Pancrustacea, <it>TipE </it>gene family members have experienced intronic nesting, escape from nesting, retrotransposition, translocation, and gene loss events while generally maintaining their local gene neighbourhoods. <it>D. melanogaster TipE</it>-like genes exhibit coordinated spatial and temporal regulation of expression distinct from their host gene but well-correlated with their regulatory target, the Para Na<sub>V </sub>channel, suggesting that functional constraints may preserve the <it>TipE </it>gene cluster. We identified homology between TipE-like Na<sub>V </sub>channel regulators and vertebrate Slo-beta auxiliary subunits of big-conductance calcium-activated potassium (BK<sub>Ca</sub>) channels, which suggests that ion channel regulatory partners have evolved distinct lineage-specific characteristics.</p> <p>Conclusions</p> <p><it>TipE</it>-like genes form a remarkably conserved genomic cluster across all examined insect genomes. This study reveals likely structural and functional constraints on the genomic evolution of insect <it>TipE </it>gene family members maintained in synteny over hundreds of millions of years of evolution. The likely common origin of these Na<sub>V </sub>channel regulators with BK<sub>Ca </sub>auxiliary subunits highlights the evolutionary plasticity of ion channel regulatory mechanisms.</p
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