879 research outputs found

    Aerobic capacity, activity levels and daily energy expenditure in male and female adolescents of the kenyan nandi sub-group

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    The relative importance of genetic and socio-cultural influences contributing to the success of east Africans in endurance athletics remains unknown in part because the pre-training phenotype of this population remains incompletely assessed. Here cardiopulmonary fitness, physical activity levels, distance travelled to school and daily energy expenditure in 15 habitually active male (13.9±1.6 years) and 15 habitually active female (13.9±1.2) adolescents from a rural Nandi primary school are assessed. Aerobic capacity ([Formula: see text]) was evaluated during two maximal discontinuous incremental exercise tests; physical activity using accelerometry combined with a global positioning system; and energy expenditure using the doubly labelled water method. The [Formula: see text] of the male and female adolescents were 73.9±5.7 ml(.) kg(-1.) min(-1) and 61.5±6.3 ml(.) kg(-1.) min(-1), respectively. Total time spent in sedentary, light, moderate and vigorous physical activities per day was 406±63 min (50% of total monitored time), 244±56 min (30%), 75±18 min (9%) and 82±30 min (10%). Average total daily distance travelled to and from school was 7.5±3.0 km (0.8-13.4 km). Mean daily energy expenditure, activity-induced energy expenditure and physical activity level was 12.2±3.4 MJ(.) day(-1), 5.4±3.0 MJ(.) day(-1) and 2.2±0.6. 70.6% of the variation in [Formula: see text] was explained by sex (partial R(2) = 54.7%) and body mass index (partial R(2) = 15.9%). Energy expenditure and physical activity variables did not predict variation in [Formula: see text] once sex had been accounted for. The highly active and energy-demanding lifestyle of rural Kenyan adolescents may account for their exceptional aerobic fitness and collectively prime them for later training and athletic success

    Pituitary models

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    pre-printPituitary tumor animal models provide researchers a microenvironment that simulates the clinical situation; however, in comparison with astrocytoma and meningioma tumor research where intracranial xenograft transplantations are increasingly being used to test various therapeutic modalities, in vivo therapeutic research on pituitary animal models focuses on direct drug therapy to the tumor because of the lack of established intracranial pituitary tumor models. The rat subcutaneous prolactin-secreting pituitary model allows investigators to noninvasively measure tumor size and the effect of direct tumor-guided therapy in a serial manner and is considered biologically relevant because it has proven to be histologically, immunocytochemically, and ultrastructurally consistent with human pituitary tumors

    Negative Effects of Paternal Age on Children's Neurocognitive Outcomes Can Be Explained by Maternal Education and Number of Siblings

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    Background: Recent findings suggest advanced paternal age may be associated with impaired child outcomes, in particular, neurocognitive skills. Such patterns are worrisome given relatively universal trends in advanced countries toward delayed nuptiality and fertility. But nature and nurture are both important for child outcomes, and it is important to control for both when drawing inferences about either pathway. Methods and Findings: We examined cross-sectional patterns in six developmental outcome measures among children in the U.S. Collaborative Perinatal Project (n = 31,346). Many of these outcomes at 8 mo, 4 y, and 7 y of age (Bayley scales, Stanford Binet Intelligence Scale, Graham-Ernhart Block Sort Test, Wechsler Intelligence Scale for Children, Wide Range Achievement Test) are negatively correlated with paternal age when important family characteristics such as maternal education and number of siblings are not included as covariates. But controlling for family characteristics in general and mother’s education in particular renders the effect of paternal age statistically insignificant for most developmental measures. Conclusions: Assortative mating produces interesting relationships between maternal and paternal characteristics that can inject spurious correlation into observational studies via omitted variable bias. Controlling for both nature and nurture reveals little residual evidence of a link between child neurocognitive outcomes and paternal age in these data. Result

    Atomic structures of TDP-43 LCD segments and insights into reversible or pathogenic aggregation.

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    The normally soluble TAR DNA-binding protein 43 (TDP-43) is found aggregated both in reversible stress granules and in irreversible pathogenic amyloid. In TDP-43, the low-complexity domain (LCD) is believed to be involved in both types of aggregation. To uncover the structural origins of these two modes of β-sheet-rich aggregation, we have determined ten structures of segments of the LCD of human TDP-43. Six of these segments form steric zippers characteristic of the spines of pathogenic amyloid fibrils; four others form LARKS, the labile amyloid-like interactions characteristic of protein hydrogels and proteins found in membraneless organelles, including stress granules. Supporting a hypothetical pathway from reversible to irreversible amyloid aggregation, we found that familial ALS variants of TDP-43 convert LARKS to irreversible aggregates. Our structures suggest how TDP-43 adopts both reversible and irreversible β-sheet aggregates and the role of mutation in the possible transition of reversible to irreversible pathogenic aggregation

    First metatarsophalangeal hemiarthroplasty for hallux rigidus

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    There is a paucity of objective information in the literature about first metatarsophalangeal (MTP) hemiarthroplasty. The authors postulate that it is a reasonable treatment option for severe hallux rigidus in selected patients. Twenty-two elective first MTP hemiarthroplasties were performed on 20 patients that met the inclusion criteria. Pre- and postoperative evaluations were done using the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score, visual analogue scale (VAS) pain score, range of motion (ROM) measurements, and radiographs. Average ROM and dorsiflexion improved by 15° and 8°, respectively. VAS pain scores improved from 5 to 2.5 after six weeks. Painless ambulation occurred after six weeks, with maximum improvement by six months. After 24 months, two patients had pain at the surgical site interfering with function, leading to an unsatisfactory result that required conversion to arthrodesis. First MTP hemiarthroplasty for severe hallux rigidus can be considered an alternative to fusion in properly selected patients who wish to maintain a functional range of motion

    The epidemiology of suicide and attempted suicide in Dutch general practice 1983–2003

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    BACKGROUND: Many patients attempting or committing suicide consult their general practitioner (GP) in the preceding period, indicating that GPs might play an important role in prevention. The aim of the present study was to analyse the epidemiology of suicidal behaviour in Dutch General Practice in order to find possible clues for prevention. METHOD: Description of trends in suicide and suicide attempts occurring from 1983–2003 in the Dutch General Practice Sentinel Network, representing 1% of the Dutch population. The data were analysed with regard to: 1) suicidal behaviour trends and their association with household situation; 2) presence of depression, treatment of depression and referral rate by GPs; 3) contact with GP before suicide or suicide attempt and discussion of suicidal ideation. RESULTS: Between 1983 and 2003 the annual number of suicide and suicide attempts decreased by 50%. Sixty percent of the patients who committed or attempted suicide were diagnosed as depressed, of whom 91% were treated by their GP with an antidepressant. Living alone was a risk factor for suicide (odds ratio 1.99; 95% CI 1.50 to 2.64), whereas living in a household of 3 or more persons was a relative risk for a suicide attempt (odds ratio 1.81; 95% CI 1.34 to 2.46). Referral to a psychiatrist or other mental health professionals occurred in 65% of the cases. GPs recalled having discussed suicidal ideation in only 7% of the cases, and in retrospect estimated that they had foreseen suicide or suicide attempts in 31% and 22% of the cases, respectively, if there had been contact in the preceding month. CONCLUSION: With regard to the prescription of antidepressants and referral of suicidal patients to a psychiatrist, Dutch GPs fulfil their role as gatekeeper satisfactorily. However, since few patients discuss their suicidal ideation with their GP, there is room for improvement. GPs should take the lead to make this subject debatable. It may improve early recognition of depressed patients at risk and accelerate their referral to mental health professionals

    Measurement of the branching fraction and CP content for the decay B(0) -> D(*+)D(*-)

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    This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APS.We report a measurement of the branching fraction of the decay B0→D*+D*- and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4  fb-1 collected at the Υ(4S) resonance during 1999–2000, we have reconstructed 38 candidate signal events in the mode B0→D*+D*- with an estimated background of 6.2±0.5 events. From these events, we determine the branching fraction to be B(B0→D*+D*-)=[8.3±1.6(stat)±1.2(syst)]×10-4. The measured CP-odd fraction of the final state is 0.22±0.18(stat)±0.03(syst).This work is supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the A.P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation

    Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.

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    The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition

    Measurement of D-s(+) and D-s(*+) production in B meson decays and from continuum e(+)e(-) annihilation at √s=10.6 GeV

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    This is the pre-print version of the Article. The official published version can be accessed from the links below. Copyright @ 2002 APSNew measurements of Ds+ and Ds*+ meson production rates from B decays and from qq̅ continuum events near the Υ(4S) resonance are presented. Using 20.8 fb-1 of data on the Υ(4S) resonance and 2.6 fb-1 off-resonance, we find the inclusive branching fractions B(B⃗Ds+X)=(10.93±0.19±0.58±2.73)% and B(B⃗Ds*+X)=(7.9±0.8±0.7±2.0)%, where the first error is statistical, the second is systematic, and the third is due to the Ds+→φπ+ branching fraction uncertainty. The production cross sections σ(e+e-→Ds+X)×B(Ds+→φπ+)=7.55±0.20±0.34pb and σ(e+e-→Ds*±X)×B(Ds+→φπ+)=5.8±0.7±0.5pb are measured at center-of-mass energies about 40 MeV below the Υ(4S) mass. The branching fractions ΣB(B⃗Ds(*)+D(*))=(5.07±0.14±0.30±1.27)% and ΣB(B⃗Ds*+D(*))=(4.1±0.2±0.4±1.0)% are determined from the Ds(*)+ momentum spectra. The mass difference m(Ds+)-m(D+)=98.4±0.1±0.3MeV/c2 is also measured.This work was supported by DOE and NSF (USA), NSERC (Canada), IHEP (China), CEA and CNRS-IN2P3 (France), BMBF (Germany), INFN (Italy), NFR (Norway), MIST (Russia), and PPARC (United Kingdom). Individuals have received support from the Swiss NSF, A. P. Sloan Foundation, Research Corporation, and Alexander von Humboldt Foundation
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