4,226 research outputs found
Dimensions of web site credibility and their relation to active trust and behavioural impact
This paper discusses two trends that threaten to undermine the effectiveness of online social marketing interventions: growing mistrust and competition. As a solution, this paper examines the relationships between Web site credibility, target audiences’ active trust and behaviour. Using structural equation modelling to evaluate two credibility models, this study concludes that Web site credibility is best considered a three-dimensional construct composed of expertise, trustworthiness and visual appeal, and that trust plays a partial mediating role between Web site credibility and behavioural impacts. The paper examines theoretical implications of conceptualizing Web sites according to a human credibility model, and factoring trust into Internet-based behavioural change interventions. Practical guidelines suggest ways to address these findings when planning online social marketing interventions
EVALUATION OF THE DEPARTMENT OF DEFENSE INSTALLATION MOSQUITO SURVEILLANCE PROGRAM, UNITED STATES 2012-2015
Master of Public HealthPublic Health Interdepartmental ProgramThu Annelise NguyenWest Nile virus (WNV) is the primary arbovirus acquired within the United States and is transmitted by the bite of a mosquito. Mosquito surveillance programs are key components of overall WNV disease surveillance programs at the local, state, and federal levels. The valuable information collected from mosquito surveillance is used to direct methods to protect public health. To consolidate human and nonhuman (including mosquito surveillance) WNV surveillance data from all states, the Centers for Disease Control and Prevention (CDC) partnered with state public health departments and created ArboNET, the national arboviral surveillance system. Mosquito surveillance programs on Department of Defense (DoD) installations provide valuable information on WNV surveillance within their state. This study was the first to evaluate ArboNET WNV mosquito surveillance data to determine if DoD installations reported to state health departments. Mosquito surveillance data was received from the Army Public Health Center (Provisional) and the Air Force School of Aerospace Medicine. Data was reviewed from 2012-2015 for Army and Air Force installations and cross- referenced with an ArboNET dataset from the CDC. From 2012-2015, Army installations did not report 46.6% (range of 0-86% annually) and Air Force installations did not report 47.4% (range of 16-81% annually) of WNV positive mosquito pools to state public health departments for inclusion into ArboNET. Improved communication, standardization of data fields collected during surveillance, and a standardized database to collect mosquito surveillance data from DoD installations could aid in the improvement of mosquito surveillance data to state health departments
Interaction Between a Linearly Polarized Electromagnetic Plane and a Double Spherical Shell
An exact solution inside, outside, and within two arbitrary concentric spherical shells is presented for an impinging monochromatic linearly polarized electromagnetic wave. Specifically, the solution was found for a double-shell spherical acrylic plastic enclosure irradiated with 2450-MHz microwaves. The enclosure is used as an environmentally controlled exposure chamber for experimental animals during microwave irradiation. The analysis shows that an air foamed material, such as styrofoam, would be a better material than either Plexiglas or Teflon, provided it is sufficiently durable
Distribution, morphology, and genetic affinities of dwarf embedded Fucus populations from the Northwest Atlantic Ocean
Dwarf embedded Fucus populations in the Northwest Atlantic Ocean are restricted to the upper intertidal zone in sandy salt marsh environments; they lack holdfasts and are from attached parental populations of F. spiralis or F. spiralis x F. vesiculosus hybrids after breakage and entanglement with halophytic marsh grasses. Dwarf forms are dichotomously branched, flat, and have a mean overall length and width of 20.3 and 1.3 mm, respectively. Thus, they are longer than Irish (mean 9.3 mm) and Alaskan (mean 15.0 mm) populations identified as F cottonii. Reciprocal transplants of different Fucus taxa in a Maine salt marsh confirm that F spiralis can become transformed into dwarf embedded thalli within the high intertidal zone, while the latter can grow into F. s. ecad lutarius within the mid intertidal zone. Thus, vertical transplantation can modify fucoid morphology and result in varying ecads. Microsatellite markers indicate that attached F spiralis and F vesiculosus are genetically distinct, while dwarf forms may arise via hybridization between the two taxa. The ratio of intermediate to species-specific-genotypes decreased with larger thalli. Also, F s. ecad lutarius consists of a mixture of intermediate and pure genotypes, while dwarf thalli show a greater frequency of hybrids
The Effects of a Commercial, Pre-exercise Energy Drink Supplement on Power, Muscular Endurance, and Repeated Sprint Speed
International Journal of Exercise Science 9(2): 205-213, 2016. The purpose of this study was to investigate the effects of ingesting a pre-workout commercial energy drink supplement on multiple parameters of physical performance, including upper body and trunk muscular endurance, muscular power, and repeated sprint speed. 19 college-aged males (n = 8) and females (n = 11) participated in this randomized, double-blind, parallel groups study. At baseline and post-testing (about one week after baseline testing), anaerobic power (assessed via a countermovement vertical jump), muscular endurance (assessed via YMCA bench press test and a curl-up test), and repeated sprint speed were assessed. Thirty minutes prior to post-testing, subjects ingested one serving (1.75 ounces [37 ml]) of a calorie-free, caffeine-containing pre-exercise energy supplement (Redline Power Rush by VPX) (n = 10) or an isovolumetric and similar tasting placebo beverage (n = 9). While vertical jump, YMCA bench press, and repeated sprint speed improved from pre to post testing in both treatment groups, there were no differences between the energy drink and placebo beverages. Curl-up endurance performance improved following the energy drink ingestion but did not improve following placebo ingestion. However, this observation also failed to reach statistical significance (p = 0.120). A possible explanation for the lack of effect of the pre-exercise energy drink to enhance physical performance was the relatively low amount of caffeine that was present in the beverage (providing an average of 2.4 mg caffeine/kg body mass)
Micrometeorological processes driving snow ablation in an Alpine catchment
Mountain snow covers typically become patchy over the course of a melting season. The snow pattern during melt is mainly governed by the end of winter snow depth distribution and the local energy balance. The objective of this study is to investigate micrometeorological processes driving snow ablation in an Alpine catchment. For this purpose we combine a meteorological model (ARPS) with a fully distributed energy balance model (Alpine3D). Turbulent fluxes above melting snow are further investigated by using data from eddy-correlation systems. We compare modelled snow ablation to measured ablation rates as obtained from a series of Terrestrial Laser Scanning campaigns covering a complete ablation season. The measured ablation rates indicate that the advection of sensible heat causes locally increased ablation rates at the upwind edges of the snow patches. The effect, however, appears to be active over rather short distances except for very strong wind conditions. Neglecting this effect, the model is able to capture the mean ablation rates for early ablation periods but strongly overestimates snow ablation once the fraction of snow coverage is below a critical value. While radiation dominates snow ablation early in the season, the turbulent flux contribution becomes important late in the season. Simulation results indicate that the air temperatures appear to overestimate the local air temperature above snow patches once the snow coverage is below a critical value. Measured turbulent fluxes support these findings by suggesting a stable internal boundary layer close to the snow surface causing a strong decrease of the sensible heat flux towards the snow cover. Thus, the existence of a stable internal boundary layer above a patchy snow cover exerts a dominant control on the timing and magnitude of snow ablation for patchy snow covers.<br/
Ion-Beam Induced Current in High-Resistance Materials
The peculiarities of electric current in high-resistance materials, such as
semiconductors or semimetals, irradiated by ion beams are considered. It is
shown that after ion--beam irradiation an unusual electric current may arise
directed against the applied voltage. Such a negative current is a transient
effect appearing at the initial stage of the process. The possibility of using
this effect for studying the characteristics of irradiated materials is
discussed. A new method for defining the mean projected range of ions is
suggested.Comment: 1 file, 7 pages, RevTex, no figure
The Effects of a Plyometric Training Program on Jump Performance in Collegiate Figure Skaters: A Pilot Study
International Journal of Exercise Science 9(2): 175-186, 2016. Plyometric training has been implemented to increase jump height in a variety of sports, but its effects have not been researched in figure skating. The purpose of this study was to determine the effects of a plyometric training program on on-ice and off-ice jump performance. Six collegiate figure skaters (19.8±1.2 years; 164.7±4.9 cm; 60.3±11.6 kg) completed a six-week sport-specific plyometric training program, consisting of low to moderate intensity plyometric exercises, while eight collegiate figure skaters (21.1±3.9 years; 162.6±6.0 cm; 60.4±6.1 kg) served as the control group. Significant increases were found for vertical jump height, standing long jump distance, (F = 31.0, p \u3c 0.001), and flight time (F = 11.6, p = 0.007). No significant differences were found for self-reported jump evaluation (p = 0.101). Six weeks of plyometric training improved both on-ice and off-ice jump performance in collegiate figure skaters, while short-term skating training alone resulted in decreases. These results indicate that figure skaters could participate in off-ice plyometric training
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