1,920 research outputs found

    Checklist of the spiders (Araneae) of British Columbia

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    In 2006, Royal British Columbia Museum (RBCM; Victoria, British Columbia) researchers began systematically documenting the full diversity of British Columbiaā€™s spider fauna. Initially, museum specimens and literature records were used to update an existing checklist and identify poorly sampled habitats in British Columbia. Annual field surveys of spiders, primarily targeting alpine and subalpine habitats, began in 2008; barcode identification of previously unidentifiable specimens commenced in 2012. These efforts have resulted in significant increases in the area of British Columbia that has been sampled for spiders, the number of species documented in the British Columbia checklist, and the number of specimens in the RBCM collection. Many of the additions to the checklist represent the first Canadian or Nearctic records of those taxa or are undescribed species. The number of species recorded in British Columbia has climbed from 212 in 1967 to 902 in 2021. Here, we present distributions for those taxa by ecoprovince and highlight the need for additional sampling efforts. The lack of conservation concern regarding spiders relative to other taxa is notable, particularly in light of the fact that more than 40% (357) of the native species of spiders in the province are represented by five or fewer collection records. The progress of the RBCMā€™s work has made the institution an important repository of western Nearctic spiders and shows that British Columbia is an important area of Nearctic spider diversity

    The EH1 motif in metazoan transcription factors

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    BACKGROUND: The Engrailed Homology 1 (EH1) motif is a small region, believed to have evolved convergently in homeobox and forkhead containing proteins, that interacts with the Drosophila protein groucho (C. elegans unc-37, Human Transducin-like Enhancers of Split). The small size of the motif makes its reliable identification by computational means difficult. I have systematically searched the predicted proteomes of Drosophila, C. elegans and human for further instances of the motif. RESULTS: Using motif identification methods and database searching techniques, I delimit which homeobox and forkhead domain containing proteins also have likely EH1 motifs. I show that despite low database search scores, there is a significant association of the motif with transcription factor function. I further show that likely EH1 motifs are found in combination with T-Box, Zinc Finger and Doublesex domains as well as discussing other plausible candidate associations. I identify strong candidate EH1 motifs in basal metazoan phyla. CONCLUSION: Candidate EH1 motifs exist in combination with a variety of transcription factor domains, suggesting that these proteins have repressor functions. The distribution of the EH1 motif is suggestive of convergent evolution, although in many cases, the motif has been conserved throughout bilaterian orthologs. Groucho mediated repression was established prior to the evolution of bilateria

    Fault rheology in an aseismic fold-thrust belt (Shahdad, eastern Iran)

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    Geodetic observations of aseismic deformation in a thrust belt near Shahdad in eastern Iran have been used to place constraints on the rheology of creeping faults in a thin-skinned thrust belt (<5 km thickness). Creep on shallow and high-angle thrust ramps at the range-front occurs at a steady rate, in response to the topographic gradient across the thrust belt. Parts of these thrust ramps, and the low-angle basal thrust they connect to at depth in a ramp-and-flat geometry, underwent accelerated creep following the nearby Mw 6.6 Fandoqa earthquake in 1998. Estimates of the rate of fault slip and the driving stresses in these two contrasting times reveal a non-linear relationship between the stresses and sliding velocity. The degree of non-linearity rules out bulk shear of a weak layer in the sedimentary section (e.g. evaporites) as the deformation mechanism. Instead, we suggest that the motions are accommodated by slip on faults governed by a friction law with a highly non-linear relationship between shear stress and slip rate (e.g. as predicted by ā€˜rate and stateā€™ models). The high-angle thrust ramps are responsible for building aspects of the geological and geomorphological signs of active shortening visible at the surface, but the folding preserved in the geology must be accomplished by other methods, possibly during the rapid transient postseismic deformation following nearby earthquakes.We thank James Jackson for use of his field photographs, and for useful dis- cussions. The SAR data used in this study were obtained from the European Space Agency. Our interferograms can be obtained from the corresponding author upon request. The topography data used was the SRTM dataset, which is freely available on the internet. RJ thanks the Marie-Curie ITN ā€˜iTECCā€™ for financial support. We thank Gilles Peltzer and two anonymous reviewers for comments that helped improve the manuscript. This work forms part of the NERC- and ESRC-funded project ā€˜Earthquakes Without Frontiersā€™.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/2015JB01243

    The role of stress-derived vesicles in the bystander effect and cancer related cachexia

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    Extracellular vesicles are small, lipid bound structures that are involved in intercellular signalling. They are known to be involved in numerous processes within the body, including in disease. One interesting function of EVs appears to be the induction of the bystander effect. The bystander effect refers to the non-targeted effects of stress, whereby stressed cells induce damage in neighbouring cells. EVs released from cells following irradiation have previously been shown to induce the bystander effect. EVs have also been implicated in the induction of cancer-cachexia, a muscle wasting disease. This disease is common in patients with cancer and is often linked to poor prognosis. In this project the ability of EVs released from heat shocked cells to induce bystander effects has been assessed. EVs released from cancer cells following 45Ā°C treatment induced the bystander effect and the bystander cells were shown to be more resistant to subsequent stress treatment. EVs retained this functionality for up to two weeks when stored at -80Ā°C. EVs released following short, 70Ā°C treatment were also able to induce bystander effects. The ability of EVs from both stressed (cisplatin) and unstressed cancer cells to induce cachexia was also examined. Cancer EVs were able to reduce differentiation in vitro, but no effects were observed when these EVs were injected into mice. The proteome of these EVs and their parent cells was also identified via liquid chromatography-mass spectrometry and pathway analysis was carried out on these proteins. These data suggest possible roles for EVs in cell-cell communication during stress and disease, with EVs being able to induce bystander effects and alter muscle development in vitro

    Feeding Habits of the Non-Native Mayan Cichlid, Mayaheros urophthalmus, in Estuarine Tributaries of Southwest Florida

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    Foraging habits of the nonā€”native Mayan Cichlid (Mayaheros urophthalmus) were investigated in the tidal tributaries to the Estero Bay and Wiggins Pass estuaries in southwest Florida (USA) during 2011ā€”2013. Dietary analysis was conducted by identifying contents in the digestive tracts of 747 fish and volumetrically measuring the food items. Detritus was the predominant food item by frequency (97ā€“100%), volume (34ā€“48%), and alimentary importance index (47ā€“64%). Bivalves, gastropods, decapod and cirriped crustaceans, coleopterans, serpulid polychaetes, and fish scales frequently (\u3e50%) occurred in samples but volume and importance differed among tributaries. Results indicate that the Mayan Cichlid in southwest Florida tidal tributaries is an opportunistic predator of hardā€”shelled invertebrates. Although there was considerable overlap in dietary composition, percent volume of food items was significantly different among tributaries during dry seasons. In each tributary, detritus was consumed in greater percentage during the dry season and benthic invertebrates were consumed in greater percentages during the wet season. Consumption of detritus, algae, and plant material may be incidental to predation on benthic invertebrates but more information is needed on digestion and assimilation of food items. Variability in diet among the tributaries in the current study and among other studies was presumably a function of habitat characteristics and the corresponding availability of prey types.

    POPEā€”a tool to aid high-throughput phylogenetic analysis

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    Summary: POPE (Phylogeny, Ortholog and Paralog Extractor) provides an integrated platform for automatic ortholog identification. Intermediate steps can be visualized, modified and analyzed in order to assess and improve the underlying quality of orthology and paralogy assignments

    Variation in structural location and amino acid conservation of functional sites in protein domain families

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    BACKGROUND: The functional sites of a protein present important information for determining its cellular function and are fundamental in drug design. Accordingly, accurate methods for the prediction of functional sites are of immense value. Most available methods are based on a set of homologous sequences and structural or evolutionary information, and assume that functional sites are more conserved than the average. In the analysis presented here, we have investigated the conservation of location and type of amino acids at functional sites, and compared the behaviour of functional sites between different protein domains. RESULTS: Functional sites were extracted from experimentally determined structural complexes from the Protein Data Bank harbouring a conserved protein domain from the SMART database. In general, functional (i.e. interacting) sites whose location is more highly conserved are also more conserved in their type of amino acid. However, even highly conserved functional sites can present a wide spectrum of amino acids. The degree of conservation strongly depends on the function of the protein domain and ranges from highly conserved in location and amino acid to very variable. Differentiation by binding partner shows that ion binding sites tend to be more conserved than functional sites binding peptides or nucleotides. CONCLUSION: The results gained by this analysis will help improve the accuracy of functional site prediction and facilitate the characterization of unknown protein sequences

    Efficacy of antiplatelet therapy in secondary prevention following lacunar stroke:Pooled analysis of randomized trials

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    Background and Purpose: Lacunar stroke accounts for ā‰ˆ25% of ischemic stroke, but optimal antiplatelet regimen to prevent stroke recurrence remains unclear. We aimed to evaluate the efficacy of antiplatelet agents in secondary stroke prevention after a lacunar stroke. Methods: We searched MEDLINE, Embase, and the Cochrane library for randomized controlled trials that reported risk of recurrent stroke or death with antiplatelet therapy in patients with lacunar stroke. We used random effects meta-analysis and evaluated heterogeneity with I2. Results: We included 17 trials with 42 234 participants (mean age 64.4 years, 65% male) and follow up ranging from 4 weeks to 3.5 years. Compared with placebo, any single antiplatelet agent was associated with a significant reduction in recurrence of any stroke (risk ratio [RR] 0.77, 0.62ā€“0.97, 2 studies) and ischemic stroke (RR 0.48, 0.30ā€“0.78, 2 studies), but not for the composite outcome of any stroke, myocardial infarction, or death (RR 0.89, 0.75ā€“1.05, 2 studies). When other antiplatelet agents (ticlodipine, cilostazol, and dipyridamole) were compared with aspirin, there was no consistent reduction in stroke recurrence (RR 0.91, 0.75ā€“1.10, 3 studies). Dual antiplatelet therapy did not confer clear benefit over monotherapy (any stroke RR 0.83, 0.68ā€“1.00, 3 studies; ischemic stroke RR 0.80, 0.62ā€“1.02, 3 studies; composite outcome RR 0.90, 0.80ā€“1.02, 3 studies). Conclusions: Our results suggest that any of the single antiplatelet agents compared with placebo in the included trials is adequate for secondary stroke prevention after lacunar stroke. Dual antiplatelet therapy should not be used for long-term stroke prevention in this stroke subtype
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