1,752 research outputs found

    Ecological Risk Aversion and Juvenile Ring-Tailed Lemur Feeding and Foraging

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    Abstract The extended primate juvenile period has been linked to interactions between feeding ecology and sociality. However, accumulating field data on juvenile primates suggest variation in the linkages between foraging efficiency, group foraging and social behaviour. In many non-human primates, juvenile ability (strength, coordination and motor skills) does not limit foraging success. If predicted limitations in feeding are not found in juvenile monkeys, it is possible that the gregarious strepsirrhines may show foraging patterns similar to those implicated in the evolution of a life history where long juvenile periods are advantageous. To test these behavioural predictions, I present a mixed longitudinal sample of observations on feeding and foraging behaviour from ring-tailed lemurs (Lemur catta) at the Bezà Mahafaly Special Reserve, Madagascar. Like several platyrrhine species, close proximity during foraging, low feeding efficiency and low dietary diversity are not typical of ring-tailed lemurs. The lack of ecological trade-offs in these species may indicate stronger common roles of sociality and social complexity in structuring the elongation of the primate juvenile period

    Key elements of effective postgraduate GP educational environments: a mixed methods study

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    Objectives Evidence in the literature suggests that satisfaction with postgraduate general practice (GP) training is associated with the quality of the educational environment. This study aimed to examine GP registrars’ level of satisfaction with a distributed model of training in a regional educational environment and investigate the relationship between satisfaction and academic performance. Study design A longitudinal 3-year study was conducted among GP registrars at James Cook University using a sequential explanatory mixed methods research design. GP registrars’ satisfaction was obtained using the scan of postgraduate educational environment domains tool. A focus group discussion was conducted to explore GP registrars’ perceptions of satisfaction with the educational environment. Setting James Cook University General Practice Training (JCU GPT) programme. Participants Six hundred and fifty one (651) GP registrars enrolled between 2016 and 2018 at JCU GPT programme. Results 651 registrars completed the satisfaction survey between 2016 and 2018. Overall, 92% of the registrars were satisfied with the educational training environment. Registrars who had become fellows reported higher satisfaction levels compared with those who were still in training (mean=4.39 vs 4.20, p=0.001). However, academic performance had no impact on level of satisfaction with the educational environment. Similarly, practice location did not influence registrars’ satisfaction rates. Four themes (rich rural/remote educational environment, supportive learning environment, readiness to continue with rural practice and practice culture) emerged from the thematic data analysis. Conclusion A clinical learning environment that focuses on and supports individual learning needs is vital for effective postgraduate medical training. This study suggests that JCU GPT programme’s distributed model fostered a satisfying and supportive training environment with rich educational experiences that enhance retention of GP registrars in rural/remote North Queensland, Australia. The findings of this study may be applicable to other settings with similar training models

    The driver landscape of sporadic chordoma.

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    Chordoma is a malignant, often incurable bone tumour showing notochordal differentiation. Here, we defined the somatic driver landscape of 104 cases of sporadic chordoma. We reveal somatic duplications of the notochordal transcription factor brachyury (T) in up to 27% of cases. These variants recapitulate the rearrangement architecture of the pathogenic germline duplications of T that underlie familial chordoma. In addition, we find potentially clinically actionable PI3K signalling mutations in 16% of cases. Intriguingly, one of the most frequently altered genes, mutated exclusively by inactivating mutation, was LYST (10%), which may represent a novel cancer gene in chordoma.Chordoma is a rare often incurable malignant bone tumour. Here, the authors investigate driver mutations of sporadic chordoma in 104 cases, revealing duplications in notochordal transcription factor brachyury (T), PI3K signalling mutations, and mutations in LYST, a potential novel cancer gene in chordoma

    Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus.

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    Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability

    Omalizumab may decrease IgE synthesis by targeting membrane IgE+ human B cells

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    Omalizumab, is a humanized anti-IgE monoclonal antibody used to treat allergic asthma. Decreased serum IgE levels, lower eosinophil and B cell counts have been noted as a result of treatment. In vitro studies and animal models support the hypothesis that omalizumab inhibits IgE synthesis by B cells and causes elimination of IgE-expressing cells either by induction of apoptosis or induction of anergy or tolerance. METHODS: We examined the influence of omalizumab on human tonsillar B cell survival and on the genes involved in IgE synthesis. Tonsillar B cells were stimulated with IL-4 plus anti-CD40 antibody to induce class switch recombination to IgE production in the presence or absence of omalizumab. Cell viability was assessed and RNA extracted to examine specific genes involved in IgE synthesis. CONCLUSIONS: We found that omalizumab reduced viable cell numbers but this was not through induction of apoptosis. IL-4R and germline Cϵ mRNA levels were decreased as well as the number of membrane IgE+ cells in B cells treated with omalizumab. These data suggest that omalizumab may decrease IgE synthesis by human B cells by specifically targeting membrane IgE-bearing B cells and inducing a state of anergy

    Circumstellar discs: What will be next?

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    This prospective chapter gives our view on the evolution of the study of circumstellar discs within the next 20 years from both observational and theoretical sides. We first present the expected improvements in our knowledge of protoplanetary discs as for their masses, sizes, chemistry, the presence of planets as well as the evolutionary processes shaping these discs. We then explore the older debris disc stage and explain what will be learnt concerning their birth, the intrinsic links between these discs and planets, the hot dust and the gas detected around main sequence stars as well as discs around white dwarfs.Comment: invited review; comments welcome (32 pages

    Engulfing tumors with synthetic extracellular matrices for cancer

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    available in PMC 2010 June 1.Local immunotherapies are under investigation for the treatment of unresectable tumors and sites of solid tumor resection to prevent local recurrence. Successful local therapy could also theoretically elicit systemic immune responses against cancer. Here we explored the delivery of therapeutic dendritic cells (DCs), cytokines, or other immunostimulatory factors to tumors via the use of ‘self-gelling’ hydrogels based on the polysaccharide alginate, injected peritumorally around established melanoma lesions. Peritumoral injection of alginate matrices loaded with DCs and/or an interleukin-15 superagonist (IL-15SA) around 14-day established ova-expressing B16F0 murine melanoma tumors promoted immune cell accumulation in the peritumoral matrix, and matrix infiltration correlated with tumor infiltration by leukocytes. Single injections of IL-15SA-carrying gels concentrated the cytokine in the tumor site ∼40-fold compared to systemic injection and enabled a majority of treated animals to suppress tumor growth for a week or more. Further, we found that single injections of alginate matrices loaded with IL-15SA and the Toll-like receptor ligand CpG or two injections of gels carrying IL-15SA alone could elicit comparable anti-tumor activity without the need for exogenous DCs. Thus, injectable alginate gels offer an attractive platform for local tumor immunotherapy, and facilitate combinatorial treatments designed to promote immune responses locally at a tumor site while limiting systemic exposure to potent immunomodulatory factors.United States. Defense Advanced Research Projects Agency ( (contract # W81XWH-04-C-0139)National Institutes of Health (U.S.) (NIH Grant EB007280)National Institutes of Health (U.S.) (NIH Grant U54-CA126515)National Institutes of Health (U.S.) (NIH Grant U54-CA112967)National Science Foundation (U.S.) (award 0348259

    cisRED: a database system for genome-scale computational discovery of regulatory elements

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    We describe cisRED, a database for conserved regulatory elements that are identified and ranked by a genome-scale computational system (). The database and high-throughput predictive pipeline are designed to address diverse target genomes in the context of rapidly evolving data resources and tools. Motifs are predicted in promoter regions using multiple discovery methods applied to sequence sets that include corresponding sequence regions from vertebrates. We estimate motif significance by applying discovery and post-processing methods to randomized sequence sets that are adaptively derived from target sequence sets, retain motifs with p-values below a threshold and identify groups of similar motifs and co-occurring motif patterns. The database offers information on atomic motifs, motif groups and patterns. It is web-accessible, and can be queried directly, downloaded or installed locally

    Distinct H3F3A and H3F3B driver mutations define chondroblastoma and giant cell tumor of bone

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    It is recognized that some mutated cancer genes contribute to the development of many cancer types, whereas others are cancer type specific. For genes that are mutated in multiple cancer classes, mutations are usually similar in the different affected cancer types. Here, however, we report exquisite tumor type specificity for different histone H3.3 driver alterations. In 73 of 77 cases of chondroblastoma (95%), we found p.Lys36Met alterations predominantly encoded in H3F3B, which is one of two genes for histone H3.3. In contrast, in 92% (49/53) of giant cell tumors of bone, we found histone H3.3 alterations exclusively in H3F3A, leading to p.Gly34Trp or, in one case, p.Gly34Leu alterations. The mutations were restricted to the stromal cell population and were not detected in osteoclasts or their precursors. In the context of previously reported H3F3A mutations encoding p.Lys27Met and p.Gly34Arg or p.Gly34Val alterations in childhood brain tumors, a remarkable picture of tumor type specificity for histone H3.3 driver alterations emerges, indicating that histone H3.3 residues, mutations and genes have distinct functions
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