12 research outputs found

    Correlations between physical and chemical defences in plants: tradeoffs, syndromes, or just many different ways to skin a herbivorous cat?

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    � Most plant species have a range of traits that deter herbivores. However, understanding of how different defences are related to one another is surprisingly weak. Many authors argue that defence traits trade off against one another, while others argue that they form coordinated defence syndromes. � We collected a dataset of unprecedented taxonomic and geographic scope (261 species spanning 80 families, from 75 sites across the globe) to investigate relationships among four chemical and six physical defences. � Five of the 45 pairwise correlations between defence traits were significant and three of these were tradeoffs. The relationship between species’ overall chemical and physical defence levels was marginally nonsignificant (P = 0.08), and remained nonsignificant after accounting for phylogeny, growth form and abundance. Neither categorical principal component analysis (PCA) nor hierarchical cluster analysis supported the idea that species displayed defence syndromes. � Our results do not support arguments for tradeoffs or for coordinated defence syndromes. Rather, plants display a range of combinations of defence traits. We suggest this lack of consistent defence syndromes may be adaptive, resulting from selective pressure to deploy a different combination of defences to coexisting species

    The Special Pathogens Research Network: Enabling Research Readiness.

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    The 2013-2016 epidemic of Ebola virus disease (EVD) that originated in West Africa underscored many of the challenges to conducting clinical research during an ongoing infectious disease epidemic, both in the most affected countries of Guinea, Liberia, and Sierra Leone, as well as in the United States and Europe, where a total of 27 patients with EVD received care in biocontainment units. The Special Pathogens Research Network (SPRN) was established in the United States in November 2016 to provide an organizational structure to leverage the expertise of the 10 Regional Ebola and Other Special Pathogen Treatment Centers (RESPTCs); it was intended to develop and support infrastructure to improve readiness to conduct clinical research in the United States. The network enables the rapid activation and coordination of clinical research in the event of an epidemic and facilitates opportunities for multicenter research when the RESPTCs are actively caring for patients requiring a biocontainment unit. Here we provide an overview of opportunities identified in the clinical research infrastructure during the West Africa EVD epidemic and the SPRN activities to meet the ongoing challenges in the context of Ebola virus and other special pathogens

    An Inflection Point of Serum 25-Hydroxyvitamin D for Maximal Suppression of Parathyroid Hormone Is Not Evident from Multi-Site Pooled Data in Children and Adolescents12

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    In adults, maximal suppression of serum parathyroid hormone (PTH) has commonly been used to determine the sufficiency of serum 25-hydroxyvitamin D [25(OH)D]. In children and adolescents, the relationship between serum 25(OH)D and PTH is less clear and most studies reporting a relationship are derived from relatively small samples and homogeneous cohorts. Our objective was to determine the relationship between serum 25(OH)D and PTH in children and adolescents from a large and diverse U.S. cohort and to identify a point of inflection of serum 25(OH)D for maximal suppression of serum PTH. Data from 735 participants, ages 7–18 y, were pooled from 3 study sites located in Indiana, Texas, and Massachusetts. A two-phase linear spline was used to model the relationship between serum 25(OH)D and PTH. The value of serum 25(OH)D for maximal suppression of serum PTH was identified as the inflection point of the spline. Before adjustment for site, the inflection point of serum 25(OH)D for maximal suppression of serum PTH was 92.4 nmol/L (95% CI: 62.2, 130.7). After adjusting for site, the point of inflection was poorly defined and the relationship between serum 25(OH)D and PTH appeared to be linear. The lack of an inflection point of serum 25(OH)D for maximal suppression of PTH brings into question the value of using maximal suppression of serum PTH as a basis for determining optimal serum 25(OH)D for healthy children and adolescents

    Mapping the differences in care for 5,000 Spinal Muscular Atrophy patients, a survey of 24 national registries in North America, Australasia and Europe

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    Spinal muscular atrophy (SMA) is an autosomal recessive genetic disorder characterised by the degeneration of motor neurons and progressive muscle weakness. It is caused by homozygous deletions in the survival motor neuron gene on chromosome 5. SMA shows a wide range of clinical severity, with SMA type I patients often dying before 2\ua0years of age, whereas type III patients experience less severe clinical manifestations and can have a normal life span. Here, we describe the design, setup and utilisation of the TREAT-NMD national SMA patient registries characterised by a small, but fully standardised set of registry items and by genetic confirmation in all patients. We analyse a selection of clinical items from the SMA registries in order to provide a snapshot of the clinical data stratified by SMA subtype, and compare these results with published recommendations on standards of care. Our study included 5,068 SMA patients in 25 countries. A total of 615 patients were ventilated, either invasively (178) or non-invasively (437), 439 received tube feeding and 455 had had scoliosis surgery. Some of these interventions were not available to patients in all countries, but differences were also noted among high-income countries with comparable wealth and health care systems. This study provides the basis for further research, such as quality of life in ventilated SMA patients, and will inform clinical trial planning
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