2,006 research outputs found

    Preschool Participation and BMI at Kindergarten Entry: The Case for Early Behavioral Intervention

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    Preschool years (ages 3–5) are a critical period in growth and development. Emerging studies suggest that preschool attendance may be linked to future weight, and perhaps obesity. This study examined relationships between public preschool attendance, demographic variables, and weight at kindergarten entry. Participants included 2,400 children entering kindergarten in 2006. Height and weight were used to calculate a child's BMI category based on CDC norms. At kindergarten entry, 17% of participants were overweight, and 18% were obese. Children attending a public preschool were at an increased risk for overweight (OR = 1.06) and obesity (OR = 1.34) at kindergarten entry, χ2(2) = 6.81, P = .03 relative to children who did not attend preschool. No significant trends relationships between demographics and weight status were found, but demographic variables are summarized descriptively. Policy and clinical implications are provided

    Integrating Interactive Web-Based Technology to Assess Adherence and Clinical Outcomes in Pediatric Sickle Cell Disease

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    Research indicates that the quality of the adherence assessment is one of the best predictors for improving clinical outcomes. Newer technologies represent an opportunity for developing high quality standardized assessments to assess clinical outcomes such as patient experience of care but have not been tested systematically in pediatric sickle cell disease (SCD). The goal of the current study was to pilot an interactive web-based tool, the Take-Charge Program, to assess adherence to clinic visits and hydroxyurea (HU), barriers to adherence, solutions to overcome these barriers, and clinical outcomes in 43 patients with SCD age 6–21 years. Results indicate that the web-based tool was successfully integrated into the clinical setting while maintaining high patient satisfaction (>90%). The tool provided data consistent with the medical record, staff report, and/or clinical lab data. Participants reported that forgetting and transportation were major barriers for adherence to both clinic attendance and HU. A greater number of self-reported barriers (P < .01) and older age (P < .05) were associated with poorer clinic attendance and HU adherence. In summary, the tool represents an innovative approach to integrate newer technology to assess adherence and clinical outcomes for pediatric patients with SCD

    Evolution of Vibrational Spectra in the Manganese-Silicon Clusters Mn<sub>2</sub>Si<sub>n</sub>, n = 10, 12, and 13, and Cationic [Mn<sub>2</sub>Si<sub>13</sub>]<sup>+</sup>

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    A comparison of DFT-computed and measured infrared spectra reveals the ground state structures of a series of gas-phase silicon clusters containing a common Mn2 unit. Mn2Si12 and [Mn2Si13]+ are both axially symmetric, allowing for a clean separation of the vibrational modes into parallel (a1) and perpendicular (e1) components. Information about the Mn–Mn and Mn–Si bonding can be extracted by tracing the evolution of these modes as the cluster increases in size. In [Mn2Si13]+ where the antiprismatic core is capped on both hexagonal faces, a relatively simple spectrum emerges that reflects a pseudo-D6d geometry. In cases where the cluster is more polar, either because there is no capping atom in the lower face (Mn2Si12) or the capping atom is present but displaced off the principal axis (Mn2Si13), the spectra include additional features derived from vibrational modes that are forbidden in the parent antiprism

    Universal fluctuations in heavy-ion collisions in the Fermi energy domain

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    We discuss the scaling laws of both the charged fragments multiplicity fluctuations and the charge of the largest fragment fluctuations for Xe+Sn collisions in the range of bombarding energies between 25 MeV/A and 50 MeV/A. We show close to E_{lab}=32 MeV/A the transition in the fluctuation regime of the charge of the largest fragment which is compatible with the transition from the ordered to disordered phase of excited nuclear matter. The size (charge) of the largest fragment is closely related to the order parameter characterizing this process.Comment: 4 pages, 3 figure

    Sampling Local Fungal Diversity in an Undergraduate Laboratory using DNA Barcoding

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    Traditional methods for fungal species identification require diagnostic morphological characters and are often limited by the availability of fresh fruiting bodies and local identification resources. DNA barcoding offers an additional method of species identification and is rapidly developing as a critical tool in fungal taxonomy. As an exercise in an undergraduate biology course, we identified 9 specimens collected from the Hendrix College campus in Conway, Arkansas, USA to the genus or species level using morphology. We report that DNA barcoding targeting the internal transcribed spacer (ITS) region supported several of our taxonomic determinations and we were able to contribute 5 ITS sequences to GenBank that were supported by vouchered collection information. We suggest that small-scale barcoding projects are possible and that they have value for documenting fungal diversity

    Evaluation of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA

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    Citation: Dryden, M. W., Smith, V., Chwala, M., Jones, E., Crevoiserat, L., McGrady, J. C., . . . Carithers, D. (2015). Evaluation of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA. Parasites & Vectors, 8, 7. doi:10.1186/s13071-015-0897-zBackground: A study was conducted to evaluate the effectiveness of afoxolaner chewables to control flea populations in naturally infested dogs in private residences in Tampa FL, USA. Evaluations of on-animal and premises flea burdens, flea sex structure and fed-unfed premises flea populations were conducted to more accurately assess flea population dynamics in households. Methods: Thirty seven naturally flea infested dogs in 23 homes in Tampa, FL were enrolled in the study and treated with afoxolaner chewables. Chewables (NexGard (R) Chewables; Merial) were administered according to label directions by study investigators on study day 0 and once again between study days 28 and 30. Flea infestations on pets were assessed using visual area thumb counts and premises flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, and once between study days 28-30, 40-45, and 54-60. Results: Within 7 days of administration of afoxolaner chewable tablets, flea counts on dogs were reduced by 99.3 %. By one month post-treatment, total flea counts on dogs were reduced by 99.9 %, with 97.3 % (36/37) of the dogs being flea free. Following the second dosing on study day 28-30, total on-dog flea burden was reduced by 100 % on days 40-45 and 54-60. On day 0, the traps collected a geometric mean of 18.2 fleas. Subsequent reductions in emerging flea populations were 97.7 and 100 % by days 28-30 and 54-60, respectively. There were 515 total fleas (Ctenocephalides felis felis) collected in the intermittent light flea traps on day 0, and 40.4 % of those fleas displayed visual evidence of having fed. Seven days after initial treatment, only 13.1 % of the fleas contained blood and by day 14 only 4.9 % of the fleas collected in traps displayed evidence of having fed. On day 0, prior to treatment, 60 % of the unfed fleas collected in intermittent-light flea traps were females, but by days 28-30, unfed males accounted for 78 % of the population. Conclusions: This in-home investigation conducted during the summer of 2014 in subtropical Tampa, FL demonstrated that afoxolaner chewables rapidly and effectively eliminated flea populations in infested dogs and homes

    Kinetics of fragmentation-annihilation processes

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    We investigate the kinetics of systems in which particles of one species undergo binary fragmentation and pair annihilation. In the latter, nonlinear process, fragments react at collision to produce an inert species, causing loss of mass. We analyse these systems in the reaction-limited regime by solving a continuous model within the mean-field approximation. The rate of fragmentation, for a particle of mass xx to break into fragments of masses yy and x−yx-y, has the form xλ−1x^{\lambda-1} (λ>0\lambda>0), and the annihilation rate is constant and independent of the masses of the reactants. We find that the asymptotic regime is characterized by the annihilation of small-mass clusters. The results are compared with those for a model with linear mass-loss (i.e.\ with a sink). We also study more complex models, in which the processes of fragmentation and annihilation are controlled by mutually-reacting catalysts. Both pair- and linear-annihilation are considered. Depending on the specific model and initial densities of the catalysts, the time-decay of the cluster-density can now be very unconventional and even non-universal. The interplay between the intervening processes and the existence of a scaling regime are determined by the asymptotic behaviour of the average-mass and of the mass-density, which may either decay indefinitely or tend to a constant value. We discuss further developments of this class of models and their potential applications.Comment: 16 pages(LaTeX), submitted to Phys. Rev.

    Thermal Degradation of Adsorbed Bottle-Brush Macromolecules: Molecular Dynamics Simulation

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    The scission kinetics of bottle-brush molecules in solution and on an adhesive substrate is modeled by means of Molecular Dynamics simulation with Langevin thermostat. Our macromolecules comprise a long flexible polymer backbone with LL segments, consisting of breakable bonds, along with two side chains of length NN, tethered to each segment of the backbone. In agreement with recent experiments and theoretical predictions, we find that bond cleavage is significantly enhanced on a strongly attractive substrate even though the chemical nature of the bonds remains thereby unchanged. We find that the mean bond life time decreases upon adsorption by more than an order of magnitude even for brush molecules with comparatively short side chains $N=1 \div 4$. The distribution of scission probability along the bonds of the backbone is found to be rather sensitive regarding the interplay between length and grafting density of side chains. The life time declines with growing contour length LL as ∝L−0.17\propto L^{-0.17}, and with side chain length as ∝N−0.53\propto N^{-0.53}. The probability distribution of fragment lengths at different times agrees well with experimental observations. The variation of the mean length L(t)L(t) of the fragments with elapsed time confirms the notion of the thermal degradation process as a first order reaction.Comment: 15 pages, 7 figure

    Territory occupancy and breeding success of peregrine falcons Falco peregrinus at various stages of population recovery

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    Organochlorine pesticides disrupted reproduction and killed many raptorial birds, and contributed to population declines during the 1940s to 1970s. We sought to discern whether and to what extent territory occupancy and breeding success changed from the pesticide era to recent years in a resident population of Peregrine Falcons Falco peregrinus in southern Scotland using long-term (1964–2015) field data and multi-state, multi-season occupancy models. Peregrine territories that were occupied with successful reproduction in one year were much more likely to be occupied and experience reproductive success in the following year, compared with those that were unoccupied or occupied by unsuccessful breeders in the previous year. Probability of territory occupancy differed between territories in the eastern and western parts of the study area, and varied over time. The probability of occupancy of territories that were unoccupied and those that were occupied with successful reproduction during the previous breeding season generally increased over time, whereas the probability of occupancy of territories that were occupied after failed reproduction decreased. The probability of reproductive success (conditional on occupancy) in territories that were occupied during the previous breeding season increased over time. Specifically, for territories that had been successful in the previous year, the probability of occupancy as well as reproductive success increased steadily over time; these probabilities were substantially higher in recent years than earlier, when the population was still exposed to direct or residual effects of organochlorine pesticides. These results are consistent with the hypothesis that progressive reduction, followed by a complete ban, in the use of organochlorine pesticides improved reproductive success of Peregrines in southern Scotland. Differences in the temporal pattern of probability of reproductive success between south-eastern and south-western Scotland suggest that the effect of organochlorine pesticides on Peregrine reproductive success and/or the recovery from pesticide effects varied geographically and was possibly affected by other factors such as persecution
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