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51.
In a predator–prey system, prey species may adapt to the presence of predators with behavioral changes such as increased vigilance, shifting habitats, or changes in their mobility. In North America, moose (Alces alces) have shown behavioral adaptations to presence of predators, but such antipredator behavioral responses have not yet been found in Scandinavian moose in response to the recolonization of wolves (Canis lupus). We studied travel speed and direction of movement of GPS‐collared female moose (n = 26) in relation to spatiotemporal differences in wolf predation risk, reproductive status, and time of year. Travel speed was highest during the calving (May–July) and postcalving (August–October) seasons and was lower for females with calves than females without calves. Similarly, time of year and reproductive status affected the direction of movement, as more concentrated movement was observed for females with calves at heel, during the calving season. We did not find support for that wolf predation risk was an important factor affecting moose travel speed or direction of movement. Likely causal factors for the weak effect of wolf predation risk on mobility of moose include high moose‐to‐wolf ratio and intensive hunter harvest of the moose population during the past century.  相似文献   
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Emerging pathogens are a growing threat to human health, agriculture and the diversity of ecological communities but may also help control problematic species. Here we investigated the diversity, distribution and consequences of emerging fungal pathogens infecting an aggressive invasive grass that is rapidly colonising habitats throughout the eastern USA. We document the recent emergence and accumulation over time of diverse pathogens that are members of a single fungal genus and represent multiple, recently described or undescribed species. We also show that experimental suppression of these pathogens increased host performance in the field, demonstrating the negative effects of emerging pathogens on invasive plants. Our results suggest that invasive species can facilitate pathogen emergence and amplification, raising concerns about movement of pathogens among agricultural, horticultural, and wild grasses. However, one possible benefit of pathogen accumulation is suppression of aggressive invaders over the long term, potentially abating their negative impacts on native communities.  相似文献   
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This study developed a parametric methodology to robustly predict occupant injuries sustained in real-world crashes using a finite element (FE) human body model (HBM). One hundred and twenty near-side impact motor vehicle crashes were simulated over a range of parameters using a Toyota RAV4 (bullet vehicle), Ford Taurus (struck vehicle) FE models and a validated human body model (HBM) Total HUman Model for Safety (THUMS). Three bullet vehicle crash parameters (speed, location and angle) and two occupant parameters (seat position and age) were varied using a Latin hypercube design of Experiments. Four injury metrics (head injury criterion, half deflection, thoracic trauma index and pelvic force) were used to calculate injury risk. Rib fracture prediction and lung strain metrics were also analysed. As hypothesized, bullet speed had the greatest effect on each injury measure. Injury risk was reduced when bullet location was further from the B-pillar or when the bullet angle was more oblique. Age had strong correlation to rib fractures frequency and lung strain severity. The injuries from a real-world crash were predicted using two different methods by (1) subsampling the injury predictors from the 12 best crush profile matching simulations and (2) using regression models. Both injury prediction methods successfully predicted the case occupant's low risk for pelvic injury, high risk for thoracic injury, rib fractures and high lung strains with tight confidence intervals. This parametric methodology was successfully used to explore crash parameter interactions and to robustly predict real-world injuries.  相似文献   
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Centromeric histone H3, CENP-ACse4, is essential for faithful chromosome segregation. Stringent regulation of cellular levels of CENP-ACse4 restricts its localization to centromeres. Mislocalization of CENP-ACse4 is associated with aneuploidy in yeast and flies and tumorigenesis in human cells; thus defining pathways that regulate CENP-A levels is critical for understanding how mislocalization of CENP-A contributes to aneuploidy in human cancers. Previous work in budding yeast shows that ubiquitination of overexpressed Cse4 by Psh1, an E3 ligase, partially contributes to proteolysis of Cse4. Here we provide the first evidence that Cse4 is sumoylated by E3 ligases Siz1 and Siz2 in vivo and in vitro. Ubiquitination of Cse4 by the small ubiquitin-related modifier (SUMO)-targeted ubiquitin ligase (STUbL) Slx5 plays a critical role in proteolysis of Cse4 and prevents mislocalization of Cse4 to euchromatin under normal physiological conditions. Accumulation of sumoylated Cse4 species and increased stability of Cse4 in slx5∆ strains suggest that sumoylation precedes ubiquitin-mediated proteolysis of Cse4. Slx5-mediated Cse4 proteolysis is independent of Psh1, since slx5∆ psh1∆ strains exhibit higher levels of Cse4 stability and mislocalization than either slx5∆ or psh1∆ strains. Our results demonstrate a role for Slx5 in ubiquitin-mediated proteolysis of Cse4 to prevent its mislocalization and maintain genome stability.  相似文献   
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Epstein-Barr virus (EBV) is a human herpesvirus that infects over 90% of the world's population that persists as a latent infection in various lymphoid and epithelial malignancies. The total number of EBV associated malignancies is estimated to exceed 200,000 new cancers per year. Current chemotherapeutic treatments of EBV-positive cancers include broad-spectrum cytotoxic drugs that ignore the EBV positive status of tumors and have limited safety and selectivity. In an effort to develop new and more efficacious molecules for inducing EBV reactivation, we have developed high-throughput screening assays to identify a class of small molecules (referred to as the C60 series) that efficiently activate the EBV lytic cycle in multiple latency types, including lymphoblastoid and nasopharyngeal carcinoma cell lines. In this paper we report our preliminary structure activity relationship studies and demonstrate reactivation of EBV in the SNU719 gastric carcinoma mouse model and the AGS-Akata gastric carcinoma mouse model.  相似文献   
57.
Wang  Yu  Liu  Di  Crowell  Laura E.  Love  Kerry R.  Wu  Shiaw-lin  Hancock  William S. 《Amino acids》2019,51(9):1353-1363
Amino Acids - Interferons are signaling proteins that belong to the large class of cytokines and human interferons which are classified based on the type of receptor interactions: type I, II and...  相似文献   
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The product of the Msx1 gene is a potent inhibitor of muscle differentiation. Msx1 is expressed in muscle precursor cells of the limb bud that also express Pax3. It is thought that Msx1 may facilitate distal migration by delaying myogenesis in these cells. Despite the role played by Msx1 in inhibiting muscle differentiation, nothing is known of the mechanisms that support the expression of the Msx1 gene within limb bud muscle precursor cells. In the present study we have used a combination of comparative genomics, mouse transgenic analysis, in situ hybridisation and immunohistochemistry to identify a highly conserved and tissue-specific regulatory sub-domain within the previously characterised Msx1 gene proximal enhancer element that supports the expression of the Msx1 gene in Pax3-expressing mouse limb pre-muscle masses. Furthermore, using a combination of in situ hybridisation, in vivo ChIP assay and transgenic explant culture analysis we provide evidence that Msx1 expression in limb bud muscle precursor cells is dependent on the canonical Wnt/TCF signalling pathway that is important in muscle shape formation. The results of these studies provide evidence of a mechanistic link between the Wnt/TCF and the Msx1/Pax3/MyoD pathways within limb bud muscle precursor cells.  相似文献   
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