255 research outputs found

    Fruits, Frugivores, and the Evolution of Phytochemical Diversity

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    Plants produce an enormous diversity of secondary metabolites, but the evolutionary mechanisms that maintain this diversity are still unclear. The interaction diversity hypothesis suggests that complex chemical phenotypes are maintained because different metabolites benefit plants in different pairwise interactions with a diversity of other organisms. In this synthesis, we extend the interaction diversity hypothesis to consider that fruits, as potential hotspots of interactions with both antagonists and mutualists, are likely important incubators of phytochemical diversity. We provide a case study focused on the Neotropical shrub Piper reticulatum that demonstrates: 1) secondary metabolites in fruits have complex and cascading effects for shaping the outcome of both mutualistic and antagonistic fruit–frugivore interactions, and; 2) fruits can harbor substantially higher levels of phytochemical diversity than leaves, even though leaves have been the primary focus of plant chemical ecology research for decades. We then suggest a number of research priorities for integrating chemical ecology with fruit–frugivore interaction research and make specific, testable predictions for patterns that should emerge if fruit interaction diversity has helped shape phytochemical diversity. Testing these predictions in a range of systems will provide new insight into the mechanisms driving frugivory and seed dispersal and shape an improved, whole-plant perspective on plant chemical trait evolution

    Proton Beam Therapy Versus Conformal Photon Radiation Therapy for Childhood Craniopharyngioma: Multi-institutional Analysis of Outcomes, Cyst Dynamics, and Toxicity

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    PurposeWe compared proton beam therapy (PBT) with intensity modulated radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease control, cyst dynamics, and toxicity.Methods and MaterialsWe reviewed records from 52 children treated with PBT (n=21) or IMRT (n=31) at 2 institutions from 1996-2012. Endpoints were overall survival (OS), disease control, cyst dynamics, and toxicity.ResultsAt 59.6 months' median follow-up (PBT 33 mo vs IMRT 106 mo; P<.001), the 3-year outcomes were 96% for OS, 95% for nodular failure-free survival and 76% for cystic failure-free survival. Neither OS nor disease control differed between treatment groups (OS P=.742; nodular failure-free survival P=.546; cystic failure-free survival P=.994). During therapy, 40% of patients had cyst growth (20% requiring intervention); immediately after therapy, 17 patients (33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs 19% PBT; P=.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT; P=.353), with intervention required in 40%. Toxicity did not differ between groups. On multivariate analysis, cyst growth was related to visual and hypothalamic toxicity (P=.009 and .04, respectively). Patients given radiation as salvage therapy (for recurrence) rather than adjuvant therapy had higher rates of visual and endocrine (P=.017 and .024, respectively) dysfunction.ConclusionsSurvival and disease-control outcomes were equivalent for PBT and IMRT. Cyst growth is common, unpredictable, and should be followed during and after therapy, because it contributes to late toxicity. Delaying radiation therapy until recurrence may result in worse visual and endocrine function

    Fecal Incontinence in US Adults: Epidemiology and Risk Factors

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    The study aims were to estimate the prevalence of different types and frequencies of fecal incontinence (FI), describe demographic factors, and identify risk factors

    Conventional and alternative pre-harvest treatments affect the quality of ‘Golden Delicious’ and ‘York’ apple fruit

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    Apple trees cv. ‘Golden Delicious’ and ‘York’ were sprayed from bloom to fruit maturity with different products to evaluate the effect of pre-harvest treatments on fruit quality, including insect/disease damage and physicochemical fruit traits. Apple trees were assigned to five treatments: unsprayed (control), holistic solution (foliar nutrients and probiotics), insecticides, antimicrobials (fungicides and antibiotics), and a combination of antimicrobials + insecticides. The treatments started soon after bloom and were carried out every two weeks until fruit were ready to harvest. Diseases such as sooty blotch (complex of several fungi) and flyspeck (Zygophiala jamaicensis Mason) were the major source of damage on fruits. ‘Golden Delicious’ trees had a higher percentage of undamaged fruit than ‘York’, but all trees had some percentage of damaged fruit. Damage was most severe in the control (unsprayed) and insecticide treatments, intermediate in the holistic treatment, and much lower in the antimicrobial and antimicrobial + insecticide treatments (p < 0.003 for all comparisons). There was also a significant interactive effect (p < .0001) of cultivars and pre-harvest spray treatment on apple fruit mass. For both cultivars there was a strong effect of spray treatment on size, with larger apples produced in the antimicrobial and antimicrobial + insecticide treatments, but these effects were more pronounced in 'York' than in 'Golden Delicious' apples. ‘Golden Delicious’ trees produced 1.4-fold heavier and bigger fruits compared to ‘York’ and ‘Golden Delicious’ fruit were more mature than ‘York’ at harvest. Pre-harvest treatments also affected other quality parameters of apple fruit, such as soluble solids content (SSC) and starch-iodine index. Using partial least squares discriminant analysis (PLS-DA), ‘Golden Delicious’ fruit could be well classified according to the holistic, antimicrobial, and antimicrobial + insecticide treatments. Control and insecticide samples clustered together, indicating similarities between fruit quality. Overall, pre-harvest spray treatment affected the quality of ‘Golden Delicious’ and ‘York’ apples, mainly the fruit mass and disease infection

    Targeted massively parallel sequencing of autism spectrum disorder-associated genes in a case control cohort reveals rare loss-of-function risk variants

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    BACKGROUND: Autism spectrum disorder (ASD) is highly heritable, yet genome-wide association studies (GWAS), copy number variation screens, and candidate gene association studies have found no single factor accounting for a large percentage of genetic risk. ASD trio exome sequencing studies have revealed genes with recurrent de novo loss-of-function variants as strong risk factors, but there are relatively few recurrently affected genes while as many as 1000 genes are predicted to play a role. As such, it is critical to identify the remaining rare and low-frequency variants contributing to ASD. METHODS: We have utilized an approach of prioritization of genes by GWAS and follow-up with massively parallel sequencing in a case-control cohort. Using a previously reported ASD noise reduction GWAS analyses, we prioritized 837 RefSeq genes for custom targeting and sequencing. We sequenced the coding regions of those genes in 2071 ASD cases and 904 controls of European white ancestry. We applied comprehensive annotation to identify single variants which could confer ASD risk and also gene-based association analysis to identify sets of rare variants associated with ASD. RESULTS: We identified a significant over-representation of rare loss-of-function variants in genes previously associated with ASD, including a de novo premature stop variant in the well-established ASD candidate gene RBFOX1. Furthermore, ASD cases were more likely to have two damaging missense variants in candidate genes than controls. Finally, gene-based rare variant association implicates genes functioning in excitatory neurotransmission and neurite outgrowth and guidance pathways including CACNAD2, KCNH7, and NRXN1. CONCLUSIONS: We find suggestive evidence that rare variants in synaptic genes are associated with ASD and that loss-of-function mutations in ASD candidate genes are a major risk factor, and we implicate damaging mutations in glutamate signaling receptors and neuronal adhesion and guidance molecules. Furthermore, the role of de novo mutations in ASD remains to be fully investigated as we identified the first reported protein-truncating variant in RBFOX1 in ASD. Overall, this work, combined with others in the field, suggests a convergence of genes and molecular pathways underlying ASD etiology. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13229-015-0034-z) contains supplementary material, which is available to authorized users

    Mindfulness for irritable bowel syndrome: protocol development for a controlled clinical trial

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    <p>Abstract</p> <p>Background</p> <p>Irritable bowel syndrome (IBS), a functional bowel disorder with symptoms of abdominal pain and disturbed defecation experienced by 10% of U.S. adults, results in significant disability, impaired quality of life, and health-care burden. Conventional medical care focusing on pharmacological approaches, diet, and lifestyle management has been partially effective in controlling symptoms. Behavioral treatments, such as cognitive-behavioral therapy and hypnosis, are promising. This paper describes an on-going feasibility study to assess the efficacy of mindfulness training, a behavioral treatment involving directing and sustaining attention to present-moment experience, for the treatment of IBS.</p> <p>Methods/Design</p> <p>The study design involves randomization of adult women with IBS according to Rome II criteria, to either an eight-week mindfulness training group (based on a Mindfulness-based Stress Reduction [MBSR] format) or a previously validated IBS social-support group as an attention-control condition. The primary hypothesis is that, compared to Support Group participants, those in the Mindfulness Program will demonstrate significant improvement in IBS symptoms as measured by the IBS Symptom Severity Scale <abbrgrp><abbr bid="B1">1</abbr></abbrgrp>.</p> <p>Discussion</p> <p>214 individuals have been screened for eligibility, of whom 148 were eligible for the study. Of those, 87 were enrolled, with 21 withdrawing after having given consent. 66 have completed or are in the process of completing the interventions. It is feasible to undertake a rigorous randomized clinical trial of mindfulness training for people with IBS, using a standardized MBSR protocol adapted for those experiencing IBS, compared to a control social-support group previously utilized in IBS studies.</p> <p>Trial Registration</p> <p>Clinical Trials.gov Identifier: NCT00680693</p

    The professional knowledge that counts in Australian contemporary early childhood teacher education

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    Australia is typical of many western countries where the provision of quality early childhood services has become a government priority. The government initiatives in Australia include repeated demands for 'well-qualified' early childhood educators. As a result of these demands the preservice preparation of early childhood educators is under intense scrutiny. This scrutiny raises many questions regarding the knowledge base considered to be essential for early childhood educators and leads to further questions about who has the authority to produce this knowledge. This article explores these questions by firstly examining some of the ways Australian early childhood teacher education is situated within the current knowledge environment. This is followed by a discussion regarding the debates about what early childhood educators 'need to know'. The third section of the article traces some of the historical features of Australian early childhood teacher education, for the author argues that contemporary questions about 'which' knowledge is to be included in early childhood teacher education are best understood alongside their historical precedents. The article concludes by considering the implications of the debates for contemporary early childhood teacher education and suggests that a way forward involves reconsidering the traditional binary between theory and practical knowledge

    The nuclear receptors of Biomphalaria glabrata and Lottia gigantea: Implications for developing new model organisms

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    © 2015 Kaur et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are creditedNuclear receptors (NRs) are transcription regulators involved in an array of diverse physiological functions including key roles in endocrine and metabolic function. The aim of this study was to identify nuclear receptors in the fully sequenced genome of the gastropod snail, Biomphalaria glabrata, intermediate host for Schistosoma mansoni and compare these to known vertebrate NRs, with a view to assessing the snail's potential as a invertebrate model organism for endocrine function, both as a prospective new test organism and to elucidate the fundamental genetic and mechanistic causes of disease. For comparative purposes, the genome of a second gastropod, the owl limpet, Lottia gigantea was also investigated for nuclear receptors. Thirty-nine and thirty-three putative NRs were identified from the B. glabrata and L. gigantea genomes respectively, based on the presence of a conserved DNA-binding domain and/or ligand-binding domain. Nuclear receptor transcript expression was confirmed and sequences were subjected to a comparative phylogenetic analysis, which demonstrated that these molluscs have representatives of all the major NR subfamilies (1-6). Many of the identified NRs are conserved between vertebrates and invertebrates, however differences exist, most notably, the absence of receptors of Group 3C, which includes some of the vertebrate endocrine hormone targets. The mollusc genomes also contain NR homologues that are present in insects and nematodes but not in vertebrates, such as Group 1J (HR48/DAF12/HR96). The identification of many shared receptors between humans and molluscs indicates the potential for molluscs as model organisms; however the absence of several steroid hormone receptors indicates snail endocrine systems are fundamentally different.The National Centre for the Replacement, Refinement and Reduction of Animals in Research, Grant Ref:G0900802 to CSJ, LRN, SJ & EJR [www.nc3rs.org.uk]

    Integrative Analysis Applying the Delta Dynamic Integrated Emulator Model in South-West Coastal Bangladesh

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    A flexible meta-model, the Delta Dynamic Integrated Emulator Model (ΔDIEM), is developed to capture the socio-biophysical system of coastal Bangladesh as simply and efficiently as possible. Operating at the local scale, calculations occur efficiently using a variety of methods, including linear statistical emulators, which capture the behaviour of more complex models, internal process-based models and statistical associations. All components are tightly coupled, tested and validated, and their behaviour is explored with sensitivity tests. Using input data, the integrated model approximates the spatial and temporal change in ecosystem services and a number of livelihood, well-being, poverty and health indicators of archetypal households. Through the use of climate, socio-economic and governance scenarios plausible trajectories and futures of coastal Bangladesh can be explored
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