145 research outputs found

    Overcoming burdens in the regulation of clinical research in children. Proceedings of a consensus conference, in historical context

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    <p>Abstract</p> <p>Background</p> <p>Many investigators are concerned that the modes of implementation and enforcement of the federal regulations designed to protect children are unduly impeding pediatric clinical research.</p> <p>Objective</p> <p>To assess regulatory impediments to clinical research involving children and to develop recommendations to ameliorate them.</p> <p>Participants</p> <p>The Pediatric Endocrine Society and The Endocrine Society convened a consensus conference involving experts and stakeholders in patient-oriented research involving children and adolescents in 2008.</p> <p>Consensus process</p> <p>Following presentations that reviewed problematic issues around key regulations, participants divided into working groups to develop potential solutions that could be adopted at local and federal levels. Presentations to the full assembly were then debated. A writing committee then drafted a summary of the discussions and main conclusions, placing them in historical context, and submitted it to all participants for comment with the aim of developing consensus.</p> <p>Conclusions</p> <p>Recommendations designed to facilitate the ethical conduct of research involving children addressed the interpretation of ambiguous regulatory terms such as "minimal risk" and "condition" and called for the development by professional societies of best practice primers for common research procedures that would be informative to both investigators and institutional review boards. A call was issued for improved guidance from the Office for Human Research Protections and Food and Drug Administration as well as for the development by professional societies of a process to monitor progress in improving human subject research regulation. Finally, a need for systematic research to define the nature and extent of institutional obstacles to pediatric research was recognized.</p

    Predicting Responses of Geo-ecological Carbonate Reef Systems to Climate Change: A Conceptual Model and Review

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    Coral reefs provide critical ecological and geomorphic (e.g. sediment production for reef-fronted shoreline maintenance) services, which interact in complex and dynamic ways. These services are under threat from climate change, requiring dynamic modelling approaches that predict how reef systems will respond to different future climate scenarios. Carbonate budgets, which estimate net reef calcium carbonate production, provide a comprehensive ‘snap-shot’ assessment of reef accretionary potential and reef stability. These budgets, however, were not intended to account for the full suite of processes that maintain coral reef services or to provide predictive capacity on longer timescales (decadal to centennial). To respond to the dual challenges of enhancing carbonate budget assessments and advancing their predictive capacity, we applied a novel model elicitation and review method to create a qualitative geo-ecological carbonate reef system model that links geomorphic, ecological and physical processes. Our approach conceptualizes relationships between net carbonate production, sediment transport and landform stability, and rates knowledge confidence to reveal major knowledge gaps and critical future research pathways. The model provides a blueprint for future coral reef research that aims to quantify net carbonate production and sediment dynamics, improving our capacity to predict responses of reefs and reef-fronted shorelines to future climate change

    Percent body fat prediction equations for 8- to 17-year-old American children: Percent body fat prediction equations

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    Percent body fat equations are usually developed in specific populations and have low generalizability

    Twenty-four hours secretion pattern of serum estradiol in healthy prepubertal and pubertal boys as determined by a validated ultra-sensitive extraction RIA

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    <p>Abstract</p> <p>Background</p> <p>The role of estrogens in male physiology has become evident. However, clinically useful normative data for estradiol secretion in boys has not previously been established due to the insensitivity of current methods used in clinical routine. By use of a validated ultra-sensitive extraction RIA, our aim was to establish normative data from a group consisting of healthy boys in prepuberty and during pubertal development.</p> <p>Methods</p> <p>Sixty-two 24-hours serum profiles (6 samples/24 hours) were obtained from 44 healthy boys (ages; 7.2–18.6 years) during their pubertal development, classified into five stages: prepuberty (testis, 1–2 mL), early (testis, 3–6 mL), mid (testis, 8–12 mL), late-1 (testis,15–25 mL, not reached final height) and late-2 (testis,15–25 mL, reached final height). Serum estradiol was determined by an ultra- sensitive extraction radioimmunoassay with detection limit 4 pmol/L and functional sensitivity 6 pmol/L.</p> <p>Results</p> <p>Mean estradiol concentrations during 24-hours secretion increased from prepuberty (median: <4 (5–95 percentiles: <4 – 7) pmol/L) to early puberty (6 (<4 – 12 pmol/L) but then remained relatively constant until a marked increase between mid-puberty (8 (4 – 17) pmol/L) and late-1 (21 (12 – 37) pmol/L) puberty, followed by a slower increase until late-2 puberty (32 (20 – 47) pmol/L). The diurnal rhythm of serum estradiol was non-measurable in pre- and early puberty, but discerned in mid-puberty, and become evident in late pubertal stages with peak values at 0600 to 1000 h.</p> <p>Conclusion</p> <p>With the use of an ultra-sensitive extraction RIA, we have provided clinically useful normative data for estradiol secretion in boys.</p

    Predicting Responses of Geo-ecological Carbonate Reef Systems to Climate Change: A Conceptual Model and Review

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    [Chapter Abstract] 230Coral reefs provide critical ecological and geomorphic (e.g. sediment production for reef-fronted shoreline maintenance) services, which interact in complex and dynamic ways. These services are under threat from climate change, requiring dynamic modelling approaches that predict how reef systems will respond to different future climate scenarios. Carbonate budgets, which estimate net reef calcium carbonate production, provide a comprehensive ‘snap-shot’ assessment of reef accretionary potential and reef stability. These budgets, however, were not intended to account for the full suite of processes that maintain coral reef services or to provide predictive capacity on longer timescales (decadal to centennial). To respond to the dual challenges of enhancing carbonate budget assessments and advancing their predictive capacity, we applied a novel model elicitation and review method to create a qualitative geo-ecological carbonate reef system model that links geomorphic, ecological and physical processes. Our approach conceptualizes relationships between net carbonate production, sediment transport and landform stability, and rates knowledge confidence to reveal major knowledge gaps and critical future research pathways. The model provides a blueprint for future coral reef research that aims to quantify net carbonate production and sediment dynamics, improving our capacity to predict responses of reefs and reef-fronted shorelines to future climate change.https://nsuworks.nova.edu/occ_facbooks/1116/thumbnail.jp
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