745 research outputs found

    The evolution of coleoid cephalopods and their present biodiversity and ecology

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    The present status of phylogeny and classification in coleoid cephalopods and the effect of evolution on the present ecology and biodiversity in the group are examined. The basis of knowledge of cephalopod phylogenywas formulated by Naef in the early 1920s, and his ideas and the progress made in the intervening 75 years are investigated. In the process, the roles that transitions between pelagic and benthic habitats played in the evolution of cephalopods are noted, and the possibility is advanced that the most recent “oceanic anoxic event” may have established a time marker for the divergence of some oegopsid families. The major advances since Naef’s work are: 1. The unusual nature of Vampyroteuthis has been recognized; 2. The sister-group relationship between the Neocoleoidea and the Belemnoidea has been established, but requires further confirmation;3. Monophyly has been confirmed for the Decapodiformes (new name), Octopodiformes and Octopoda by molecular and morphological methodologies; 4. The dates of origin of the Belemnoidea, Neocoleoidea, Sepioidea and fossil teuthoids have been extended to considerably earlier times. The major unsolved phylogenetic problems in need of immediate attention are the position of the Myopsida, relationships within the Sepioidea, the identification of the basal nodes within the Oegopsida, and the relationships of most “fossil teuthoids.

    Measuring research impact: a large cancer research funding programme in Australia

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    Background: Measuring research impact is of critical interest to philanthropic and government funding agencies interested in ensuring that the research they fund is both scientifically excellent and has meaningful impact into health and other outcomes. The Beat Cancer Project (BCP) is a AUD 34mcancerresearchfundingschemethatcommencedin2011.ItwasinitiatedbyanAustraliancharity(CancerCouncilSA),andsupportedbytheSouthAustralianGovernmentandthestatesmajoruniversities.Methods:ThisstudyappliedBuxtonandHanneysPaybackFrameworktoassessresearchimpactgeneratedfromtheBCPafter3yearsoffunding.DatasourceswereanauditofpeerreviewedpublicationsfromJanuary2011toSeptember2014fromWebofKnowledgeandaselfreportsurveyofinvestigatorsawardedBCPresearchfundingduringitsfirst3yearsofimplementation(20112013).Ofthe104surveys,92(88Results:TheBCPperformedwellacrossallfivecategoriesofthePaybackFramework.Intermsofknowledgeproduction,1257peerreviewedpublicationsweregeneratedandthemeanimpactfactorofpublishingjournalsincreasedannually.Thereweremanybenefitstofutureresearchwith21respondents(2334 m cancer research funding scheme that commenced in 2011. It was initiated by an Australian charity (Cancer Council SA), and supported by the South Australian Government and the state’s major universities. Methods: This study applied Buxton and Hanney’s Payback Framework to assess research impact generated from the BCP after 3 years of funding. Data sources were an audit of peer-reviewed publications from January 2011 to September 2014 from Web of Knowledge and a self-report survey of investigators awarded BCP research funding during its first 3 years of implementation (2011–2013). Of the 104 surveys, 92 (88%) were completed. Results: The BCP performed well across all five categories of the Payback Framework. In terms of knowledge production, 1257 peer-reviewed publications were generated and the mean impact factor of publishing journals increased annually. There were many benefits to future research with 21 respondents (23%) reporting career advancement, and 110 higher degrees obtained or expected (including 84 PhDs). Overall, 52% of funded projects generated tools for future research. The funded research attracted substantial further income yielding a very high rate of leverage. For every AUD 1 that the cancer charity invested, the BCP gained an additional AUD $6.06. Five projects (5%) had informed policy and 5 (5%) informed product development, with an additional 31 (34%) and 35 (38%) projects, respectively, anticipating doing so. In terms of health and sector and broader economic benefits, 8 (9%) projects had influenced practice or behaviour of health staff and 32 (34%) would reportedly to do so in the future. Conclusions: Research impact was a priority of charity and government funders and led to a deliberate funding strategy. Emphasising research impact while maintaining rigorous, competitive processes can achieve the joint objectives of excellence in research, yielding good research impact and a high rate of leverage for philanthropic and public investment, as indicated by these early results

    Relationship between eating behaviors and physical activity of preschoolers and their peers: a systematic review

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    Abstract: Objectives: Children learn by observing and imitating others, meaning that their eating behaviors and physical activity may be influenced by their peers. This paper systematically reviews how preschoolers’ eating behaviors and physical activity relate to their peers’ behaviors, and discusses avenues for future research. Methods: Six databases were searched for quantitative, peer-reviewed studies published up to July 2015 reporting on the correlates, predictors or effectiveness of peers on eating behaviors and physical activity in preschoolers. Risk of bias was independently assessed by two evaluators using the Quality Assessment Tool for Quantitative Studies. Results: Thirteen articles were included: six measured physical activity, and seven assessed eating behaviors. Four of the six physical activity studies reported that children were more active when peers were present, while large peer group size was negatively associated with physical activity in two cross-sectional studies. All nutrition interventions reported that children’s eating behaviors may be influenced by their peers. Conclusions: Although supported by weak evidence, peers appear to influence children’s eating behaviors and physical activity. However, this influence may be moderated by the number of peers, gender, age and the perceived status of the role models. Future obesity prevention interventions should consider involving peers as agents for positive eating behaviors and physical activity in preschoolers

    Polyphenolic content and antioxidant capacity in fruits of plum (prunus domestica l.) Cultivars "valjevka" and "mildora" as influenced by air drying

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    Polyphenolic content and antioxidant capacity of freshly harvested plums cvs. "Valjevka" and "Mildora," and changes caused by drying were analyzed. Plum drying at 90C resulted in significant changes in anthocyanins, flavonoids and phenolics content, and antioxidant capacity in both cultivars examined. Statistical analysis showed that antioxidant capacity of both fresh plums and prunes of "Valjevka" and "Mildora" is strongly influenced by the phenolic constituents of the fruit. The major phenolic compound in fresh plums and prunes is neochlorogenic acid, followed by caffeic acid and chlorogenic acid. After drying, a significant decrease in neochlorogenic acid and an increase in caffeic acid was observed, while chlorogenic acid content decreased in prunes of "Valjevka," and increased in prunes of "Mildora." Rutin and protocatechuic acid contents were slightly decreased after drying, while gallic acid content was dramatically increased. A complete degradation of cyanidin was induced by drying

    “It’s hard to tell”. The challenges of scoring patients on standardised outcome measures by multidisciplinary teams: a case study of Neurorehabilitation

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    Background Interest is increasing in the application of standardised outcome measures in clinical practice. Measures designed for use in research may not be sufficiently precise to be used in monitoring individual patients. However, little is known about how clinicians and in particular, multidisciplinary teams, score patients using these measures. This paper explores the challenges faced by multidisciplinary teams in allocating scores on standardised outcome measures in clinical practice. Methods Qualitative case study of an inpatient neurorehabilitation team who routinely collected standardised outcome measures on their patients. Data were collected using non participant observation, fieldnotes and tape recordings of 16 multidisciplinary team meetings during which the measures were recited and scored. Eleven clinicians from a range of different professions were also interviewed. Data were analysed used grounded theory techniques. Results We identified a number of instances where scoring the patient was 'problematic'. In 'problematic' scoring, the scores were uncertain and subject to revision and adjustment. They sometimes required negotiation to agree on a shared understanding of concepts to be measured and the guidelines for scoring. Several factors gave rise to this problematic scoring. Team members' knowledge about patients' problems changed over time so that initial scores had to be revised or dismissed, creating an impression of deterioration when none had occurred. Patients had complex problems which could not easily be distinguished from each other and patients themselves varied in their ability to perform tasks over time and across different settings. Team members from different professions worked with patients in different ways and had different perspectives on patients' problems. This was particularly an issue in the scoring of concepts such as anxiety, depression, orientation, social integration and cognitive problems. Conclusion From a psychometric perspective these problems would raise questions about the validity, reliability and responsiveness of the scores. However, from a clinical perspective, such characteristics are an inherent part of clinical judgement and reasoning. It is important to highlight the challenges faced by multidisciplinary teams in scoring patients on standardised outcome measures but it would be unwarranted to conclude that such challenges imply that these measures should not be used in clinical practice for decision making about individual patients. However, our findings do raise some concerns about the use of such measures for performance management

    Mean sojourn time, overdiagnosis, and reduction in advanced stage prostate cancer due to screening with PSA: implications of sojourn time on screening

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    This study aimed to assess the mean sojourn time (MST) of prostate cancer, to estimate the probability of overdiagnosis, and to predict the potential reduction in advanced stage disease due to screening with PSA. The MST of prostate cancer was derived from detection rates at PSA prevalence testing in 43 842 men, aged 50–69 years, as part of the ProtecT study, from the incidence of non-screen-detected cases obtained from the English population-based cancer registry database, and from PSA sensitivity obtained from the medical literature. The relative reduction in advanced stage disease was derived from the expected and observed incidences of advanced stage prostate cancer. The age-specific MST for men aged 50–59 and 60–69 years were 11.3 and 12.6 years, respectively. Overdiagnosis estimates increased with age; 10–31% of the PSA-detected cases were estimated to be overdiagnosed. An interscreening interval of 2 years was predicted to result in 37 and 63% reduction in advanced stage disease in men 65–69 and 50–54 years, respectively. If the overdiagnosed cases were excluded, the estimated reductions were 9 and 54%, respectively. Thus, the benefit of screening in reducing advanced stage disease is limited by overdiagnosis, which is greater in older men

    Magnetic resonance imaging phantoms for quality-control of myocardial T1 and ECV mapping: specific formulation, long-term stability and variation with heart rate and temperature

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    Background: Magnetic resonance imaging (MRI) phantoms are routinely used for quality assurance in MRI centres; however their long term stability for verification of myocardial T1/ extracellular volume fraction (ECV) mapping has never been investigated. Methods: Nickel-chloride agarose gel phantoms were formulated in a reproducible laboratory procedure to mimic blood and myocardial T1 and T2 values, native and late after Gadolinium administration as used in T1/ECV mapping. The phantoms were imaged weekly with an 11 heart beat MOLLI sequence for T1 and long TR spin-echo sequences for T2, in a carefully controlled reproducible manner for 12 months. Results: There were only small relative changes seen in all the native and post gadolinium T1 values (up to 9.0 % maximal relative change in T1 values) or phantom ECV (up to 8.3 % maximal relative change of ECV, up to 2.2 % maximal absolute change in ECV) during this period. All native and post gadolinium T2 values remained stable over time with <2 % change. Temperature sensitivity testing showed MOLLI T1 values in the long T1 phantoms increasing by 23.9 ms per degree increase and short T1 phantoms increasing by 0.3 ms per degree increase. There was a small absolute increase in ECV of 0.069 % (~0.22 % relative increase in ECV) per degree increase. Variation in heart rate testing showed a 0.13 % absolute increase in ECV (~0.45 % relative increase in ECV) per 10 heart rate increase. Conclusions: These are the first phantoms reported in the literature modeling T1 and T2 values for blood and myocardium specifically for the T1mapping/ECV mapping application, with stability tested rigorously over a 12 month period. This work has significant implications for the utility of such phantoms in improving the accuracy of serial scans for myocardial tissue characterisation by T1 mapping methods and in multicentre work

    Maximal aerobic and anaerobic power generation in large crocodiles versus mammals: implications for dinosaur gigantothermy

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    Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylus porosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.Roger S. Seymou
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