Although obesity affects all cultures, ethnic groups and social strata, this disorder affects African Americans, Hispanics and the poor at a disproportionate rate. The Downstart Pediatric Healthy ...Lifestyle Program was developed to provide a multi-disciplinary behavioral modification program for inner city families in Brooklyn, New York interested in leading a healthier, more active lifestyle. The Downstart Program uses a four-pronged approach of medical evaluation, exercise, nutritional education and lifestyle modification. A psychological evaluation is performed to determine the individual's ability and readiness to participate in group activities. Baseline physical fitness, flexibility and muscle strength are measured, followed by a twice-weekly karate/martial arts/dance program, incorporating principles established by the President's Council on Exercise. Nutritional and behavioral modification aspects of the program consist of weekly education about food groups, portion control, goal setting and appropriate rewards for attaining goals. Our preliminary results indicate that the Downstart Program may be a viable intervention for weight loss. Further study is needed to improve strategies for motivating patients and means and criteria for assessing long-term effects on health and lifestyle.
This research addresses the linear flutter theory for bridges. A new model for the self-excited loads is proposed in which oscillatory variation in the loads due to motion-induced vortex activity in ...the wake, is accounted for. The addition of complex exponential terms generalizes the traditional Prony series representation of the indicial function for the self-excited loads. Turbulence in the flow direction is included in the self-excited loads. Hence the system is parametrically excited and its governing equations have randomly varying coefficients. The state vector of the response is approximated by a Markov vector process. Stochastic averaging is utilized to convert the physical equations into Ito's stochastic differential equations which govern the Markov vector process. Ito's differential rule is then used to construct the equations for the second statistical moments. Motion stability of the system is interpreted as stability of the first and second statistical moments. The computed stability boundaries for the first and second moments are shown to be crucially dependent upon the coupled loads. Unfortunately, parameters for the indicial functions calculated indirectly from the frequency-domain flutter derivatives, are nonunique. Nevertheless, it can be concluded that a bridge deck that exhibits oscillatory self-excited load behavior is generally less stable (in the mean square) than one with nonoscillatory behavior. The new model that captures the oscillatory behavior concisely, reduces the critical wind speed by more than 10%. Buffeting loads result essentially from the vertical turbulence component. In the present thesis the buffeting loads are expressed as convolution integrals, that account for past history of the fluid flow. Thus the buffeting model considered is based on unsteady aerodynamics rather than the quasi-steady model that has been traditionally used in many previous analyses. The time domain unsteady buffeting response analysis, that also incorporates the randomly varying parameters of the self-excited loads, is the first of its kind. In the illustrative examples, the unsteady buffeting effect is shown to be significant on a single-degree-of-freedom system, whereas it is comparatively less significant with a coupled two-degree-of-freedom system.
Aphids alter host-plant nitrogen isotope fractionation Wilson, Alex C.C; Sternberg, Leonel da S.L; Hurley, Katherine B
Proceedings of the National Academy of Sciences - PNAS,
06/2011, Letnik:
108, Številka:
25
Journal Article
Recenzirano
Odprti dostop
Plant sap-feeding insects and blood-feeding parasites are frequently depleted in ¹âµN relative to their diet. Unfortunately, most fluid-feeder/host nitrogen stable-isotope studies simply report ...stable-isotope signatures, but few attempt to elucidate the mechanism of isotopic trophic depletion. Here we address this deficit by investigating the nitrogen stable-isotope dynamics of a fluid-feeding herbivore-host plant system: the green peach aphid, Myzus persicae, feeding on multiple brassicaceous host plants. M. persicae was consistently more than 6per thousand depleted in ¹âµN relative to their hosts, although aphid colonized plants were 1.5per thousand to 2.0per thousand enriched in ¹âµN relative to uncolonized control plants. Isotopic depletion of aphids relative to hosts was strongly related to host nitrogen content. We tested whether the concomitant aphid ¹âµN depletion and host ¹âµN enrichment was coupled by isotopic mass balance and determined that aphid ¹âµN depletion and host ¹âµN enrichment are uncoupled processes. We hypothesized that colonized plants would have higher nitrate reductase activity than uncolonized plants because previous studies had demonstrated that high nitrate reductase activity under substrate-limiting conditions can result in increased plant δ¹âµN values. Consistent with our hypothesis, nitrate reductase activity in colonized plants was twice that of uncolonized plants. This study offers two important insights that are likely applicable to understanding nitrogen dynamics in fluid-feeder/host systems. First, isotopic separation of aphid and host depends on nitrogen availability. Second, aphid colonization alters host nitrogen metabolism and subsequently host nitrogen stable-isotope signature. Notably, this work establishes a metabolic framework for future hypothesis-driven studies focused on aphid manipulation of host nitrogen metabolism.
Abstract
Motivation
Genome-wide association studies have identified thousands of loci associated with human
disease, but identifying the causal genes at these loci is often difficult. Several
methods ...prioritize genes most likely to be disease causing through the integration of
biological data, including protein–protein interaction and phenotypic data. Data
availability is not the same for all genes however, potentially influencing the
performance of these methods.
Results
We demonstrate that whilst disease genes tend to be associated with greater numbers of
data, this may be at least partially a result of them being better studied. With this
observation we develop PhenoRank, which prioritizes disease genes whilst avoiding being
biased towards genes with more available data. Bias is avoided by comparing gene scores
generated for the query disease against gene scores generated using simulated sets of
phenotype terms, which ensures that differences in data availability do not affect the
ranking of genes. We demonstrate that whilst existing prioritization methods are biased
by data availability, PhenoRank is not similarly biased. Avoiding this bias allows
PhenoRank to effectively prioritize genes with fewer available data and improves its
overall performance. PhenoRank outperforms three available prioritization methods in
cross-validation (PhenoRank area under receiver operating characteristic curve
AUC=0.89, DADA AUC = 0.87, EXOMISER AUC = 0.71, PRINCE AUC = 0.83,
P < 2.2 × 10−16).
Availability and implementation
PhenoRank is freely available for download at https://github.com/alexjcornish/PhenoRank.
Supplementary information
Supplementary data are
available at Bioinformatics online.
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