59 research outputs found
Change in maternal body mass index is associated with offspring body mass index: a 21-year prospective study
High body-mass index (BMI; defined as 25 kg/m(2) or greater) is associated with increased risk of cancer. To inform public health policy and future research, we estimated the global burden of cancer attributable to high BMI in 2012
'Physical activity at home (PAAH)', evaluation of a group versus home based physical activity program in community dwelling middle aged adults: rationale and study design
<p>Abstract</p> <p>Background</p> <p>It is well recognised that the adoption and longer term adherence to physical activity by adults to reduce the risk of chronic disease is a challenge. Interventions, such as group and home based physical activity programs, have been widely reported upon. However few studies have directly compared these interventions over the longer term to determine their adherence and effectiveness. Participant preference for home based or group interventions is important. Some evidence suggests that home based physical activity programs are preferred by middle aged adults and provide better long term physical activity adherence. Physiotherapists may also be useful in increasing physical activity adherence, with limited research on their impact.</p> <p>Methods</p> <p>'Physical Activity at Home' is a 2 year pragmatic randomised control trial, with a non-randomised comparison to group exercise. Middle-aged adults not interested in, or unable to attend, a group exercise program will be targeted. Sedentary community dwelling 50-65 year olds with no serious medical conditions or functional impairments will be recruited via two mail outs using the Australian federal electoral roll. The first mail out will invite participants to a 6 month community group exercise program. The second mail out will be sent to those not interested in the group exercise program inviting them to take part in a home based intervention. Eligible home based participants will be randomised into a 6 month physiotherapy-led home based physical activity program or usual care. Outcome measures will be taken at baseline, 6, 12, 18 and 24 months. The primary outcome is physical activity adherence via exercise diaries. Secondary outcomes include the Active Australia Survey, accelerometry, aerobic capacity (step test), quality of life (SF-12v2), blood pressure, waist circumference, waist-to-hip ratio and body mass index. Costs will be recorded prospectively and qualitative data will be collected.</p> <p>Discussion</p> <p>The planned 18 month follow-up post intervention will provide an indication of the effectiveness of the group and home based interventions in terms of adherence to physical activity, health benefits and cost. If the physiotherapy-led home based physical activity program is successful it could provide an alternative option for physical activity program delivery across a number of settings.</p> <p>Trial registration</p> <p>Australia and New Zealand Clinical Trials Register (ANZCTR): <a href="http://www.anzctr.org.au/ACTRN12611000890932.aspx">ACTRN12611000890932</a></p
Clinical applications of cardiac CT angiography
ECG-gated multislice CT provides a cost-effective, non-invasive technology for evaluation of the coronary arteries, as well as for additional clinical applications, which require morphological assessment of the heart and adjacent structures with simultaneous evaluation of the coronary circulation
Factors That Affect Large Subunit Ribosomal DNA Amplicon Sequencing Studies of Fungal Communities: Classification Method, Primer Choice, and Error
Nuclear large subunit ribosomal DNA is widely used in fungal phylogenetics and to an increasing extent also amplicon-based environmental sequencing. The relatively short reads produced by next-generation sequencing, however, makes primer choice and sequence error important variables for obtaining accurate taxonomic classifications. In this simulation study we tested the performance of three classification methods: 1) a similarity-based method (BLAST + Metagenomic Analyzer, MEGAN); 2) a composition-based method (Ribosomal Database Project naĂŻve Bayesian classifier, NBC); and, 3) a phylogeny-based method (Statistical Assignment Package, SAP). We also tested the effects of sequence length, primer choice, and sequence error on classification accuracy and perceived community composition. Using a leave-one-out cross validation approach, results for classifications to the genus rank were as follows: BLAST + MEGAN had the lowest error rate and was particularly robust to sequence error; SAP accuracy was highest when long LSU query sequences were classified; and, NBC runs significantly faster than the other tested methods. All methods performed poorly with the shortest 50â100 bp sequences. Increasing simulated sequence error reduced classification accuracy. Community shifts were detected due to sequence error and primer selection even though there was no change in the underlying community composition. Short read datasets from individual primers, as well as pooled datasets, appear to only approximate the true community composition. We hope this work informs investigators of some of the factors that affect the quality and interpretation of their environmental gene surveys
A supermatrix analysis of genomic, morphological, and paleontological data from crown Cetacea
<p>Abstract</p> <p>Background</p> <p>Cetacea (dolphins, porpoises, and whales) is a clade of aquatic species that includes the most massive, deepest diving, and largest brained mammals. Understanding the temporal pattern of diversification in the group as well as the evolution of cetacean anatomy and behavior requires a robust and well-resolved phylogenetic hypothesis. Although a large body of molecular data has accumulated over the past 20 years, DNA sequences of cetaceans have not been directly integrated with the rich, cetacean fossil record to reconcile discrepancies among molecular and morphological characters.</p> <p>Results</p> <p>We combined new nuclear DNA sequences, including segments of six genes (~2800 basepairs) from the functionally extinct Yangtze River dolphin, with an expanded morphological matrix and published genomic data. Diverse analyses of these data resolved the relationships of 74 taxa that represent all extant families and 11 extinct families of Cetacea. The resulting supermatrix (61,155 characters) and its sub-partitions were analyzed using parsimony methods. Bayesian and maximum likelihood (ML) searches were conducted on the molecular partition, and a molecular scaffold obtained from these searches was used to constrain a parsimony search of the morphological partition. Based on analysis of the supermatrix and model-based analyses of the molecular partition, we found overwhelming support for 15 extant clades. When extinct taxa are included, we recovered trees that are significantly correlated with the fossil record. These trees were used to reconstruct the timing of cetacean diversification and the evolution of characters shared by "river dolphins," a non-monophyletic set of species according to all of our phylogenetic analyses.</p> <p>Conclusions</p> <p>The parsimony analysis of the supermatrix and the analysis of morphology constrained to fit the ML/Bayesian molecular tree yielded broadly congruent phylogenetic hypotheses. In trees from both analyses, all Oligocene taxa included in our study fell outside crown Mysticeti and crown Odontoceti, suggesting that these two clades radiated in the late Oligocene or later, contra some recent molecular clock studies. Our trees also imply that many character states shared by river dolphins evolved in their oceanic ancestors, contradicting the hypothesis that these characters are convergent adaptations to fluvial habitats.</p
Biogeographic problem-solving reveals the Late Pleistocene translocation of a short-faced bear to the California Channel Islands
An accurate understanding of biodiversity of the past is critical for contextualizing biodiversity patterns and trends in the present. Emerging techniques are refining our ability to decipher otherwise cryptic human-mediated species translocations across the Quaternary, yet these techniques are often used in isolation, rather than part of an interdisciplinary hypothesis-testing toolkit, limiting their scope and application. Here we illustrate the use of such an integrative approach and report the occurrence of North Americaâs largest terrestrial mammalian carnivore, the short-faced bear, Arctodus simus, from Daisy Cave (CA-SMI-261), an important early human occupation site on the California Channel Islands. We identified the specimen by corroborating morphological, protein, and mitogenomic lines of evidence, and evaluated the potential natural and anthropogenic mechanisms of its transport and deposition. While representing just a single specimen, our combination of techniques opened a window into the behavior of an enigmatic species, suggesting that A. simus was a wide-ranging scavenger utilizing terrestrial and marine carcasses. This discovery highlights the utility of bridging archaeological and paleontological datasets to disentangle complex biogeographic scenarios and reveal unexpected biodiversity for island systems worldwide.Open Access fees paid for in whole or in part by the University of Oklahoma Libraries
Radiocarbon and isotope laboratory work was supported in part by the NSF Archaeometry Program BCS-1460369 (to D.J.K. and B.J.C). M.B was supported by a Royal Society fellowship. Additional funding was provided by the University of Oklahoma, the University of Oregon, and the Smithsonian Institution.Ye
The scope for biased recall of risk-factor exposure in case-control studies: Evidence from a cohort study of Scottish men
Aims: Case-control studies are prone to recall bias, a participant's case-control status influencing their recall of exposure to risk factors. We aimed to demonstrate empirically the scope for this bias. Methods: Two thousand five hundred and fifty men without coronary heart disease at enrolment to a prospective cohort study underwent two health assessments, about 5 years apart. The association between the development of coronary heart disease in the intervening period and changes in reported stress and cigarette smoking were investigated. Results: Men admitted to hospital with coronary heart disease reported a greater increase in psychological stress (p=0.032) and greater cessation of smoking (22% vs. 10%; p=0.007) than men not admitted. Consequently, when exposure data are collected at the end rather than at the start of the follow-up period, coronary heart disease is observed to be more strongly associated with psychological stress, and more weakly associated with smoking. Conclusions: At the time when a case-control study is conducted, levels of exposure to risk factors will have been influenced by disease development. When participants are asked about their level of exposure for a previous time period, recall is likely to be influenced by present outcome and exposure status, especially when psychological states are being investigate
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