2,923 research outputs found
Factors Influencing Retention of Senior 4-H Club Boys in Hamilton County, Tennessee
Purpose of the Study: The purpose of this study was to try to identify some of the factors contributing to the retention and loss of senior 4-H Club boy members in Hamilton County, Tennessee
Development of a rotating gravity gradiometer for earth orbit applications (AAFE)
Some preliminary mission studies are described along with the design, fabrication, and test of a breadboard model of an earth orbital, rotating gravity gradiometer with a design goal of 10 to the minus 11th power/sec sq (0.01 EU) in a 35-sec integration time. The proposed mission uses a Scout vehicle to launch one (or two orthogonally oriented) spin-stabilized satellites into a 330-km circular polar orbit some 20 days before an equinox. During the short orbital lifetime, the experiment would obtain two complete maps of the gravity gradient field with a resolution approaching 270 km (degree 75). The breadboard model of the gradiometer demonstrated a combined thermal and electronic noise threshold of 0.015 EU per data channel. The design changes needed to reduce the noise to less than 0.01 EU were identified. Variations of the sensor output signal with temperature were experimentally determined and a suitable method of temperature compensation was developed and tested. Other possible error sources, such as sensor interaction with satellite dynamics and magnetic fields, were studied analytically and shown to be small
Trends Associated with Marbling Score, Fat Cover, and CAB (Certified Angus BeefTM) Acceptance Rate
The objective of the study was to analyze the Certified Angus Beef (CAB) program carcass database for trends associated with marbling score, fat cover, and CAB acceptance rate in Angus-type cattle. The CAB program carcass database is made up of over 100,000 records collected during 1989 to 1999. Steers make up 90 % of the database, and 89 % of the cattle were finished in the Midwest (NE, CO, KS). The majority of the cattle (62 %) were finished in Nebraska feedyards. The CAB program overall acceptance rate was 23.4 %. Marbling score (84.0 %) is the first limiting factor for CAB acceptance of steers. For steers, a combination of marbling score and yield grade (8.3 %) and yield grade alone (6.1 %) for steers are the second and third limiting factors for CAB acceptance, respectively. The phenotypic correlation between fat cover and marbling score is nearly zero for CAB steers, yet for non-CAB steers the correlation is 0.38 (p \u3c .01). On the average, as yield grade increases from 2.0 to 4.0, by each tenth of a unit, marbling score increases by 0.3 % for every 1 % increase in fat cover for all steers. Comparing CAB steers versus non-CAB steers, marbling score increases by 0.05 % and 0.34 % for every 1 % increase in fat cover, respectively. As fat cover groups increase by 0.1 of an inch, CAB acceptance rate increases up to the 0.6- 0.69 inch group, then starts to decrease for steers. When looking at marbling score by fat cover groups, CAB steers increase 1.0 % for each 0.1 inch increase in fat cover, and for non-CAB steers, there is an increase of 5.0 %. Fat cover increases by 5.6 % and 14.2 % as you go from a USDA marbling score of small to modest and slight to modest, respectively, for all steers. Looking at the slaughter months, there is an increase in marbling score from April to August, although fat cover remains steady. Yet CAB acceptance rate decreases from April to June and then increases from June to November. Producers may be able to improve the CAB acceptance rate of their cattle if there is a clearer understanding of the relationship between traits that are included in the CAB specifications
Effects of a standard provision versus an autonomy supportive exercise referral programme on physical activity, quality of life and well-being indicators:a cluster randomised controlled trial
Background: The National Institute for Health and Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the feasibility and impact of a Self Determination Theory-based (SDT) exercise referral consultation. Methods: An exploratory cluster randomised controlled trial comparing standard provision exercise referral with an exercise referral intervention grounded in Self Determination Theory. Individuals (Nâ=â347) referred to an exercise referral scheme were recruited into the trial from 13 centres. Outcomes and processes of change measured at baseline, 3 and 6-months: Minutes of self-reported moderate or vigorous physical activity (PA) per week (primary outcome), health status, positive and negative indicators of emotional well-being, anxiety, depression, quality of life (QOL), vitality, and perceptions of autonomy support from the advisor, need satisfaction (3 and 6 months only), intentions to be active, and motivational regulations for exercise. Blood pressure and weight were assessed at baseline and 6 months.Results: Perceptions of the autonomy support provided by the health and fitness advisor (HFA) did not differ by arm. Between group changes over the 6-months revealed significant differences for reported anxiety only. Within arm contrasts revealed significant improvements in anxiety and most of the Dartmouth CO-OP domains in the SDT arm at 6 months, which were not seen in the standard exercise referral group. A process model depicting hypothesized relationships between advisor autonomy support, need satisfaction and more autonomous motivation, enhanced well being and PA engagement at follow up was supported. Conclusions: Significant gains in physical activity and improvements in quality of life and well-being outcomes emerged in both the standard provision exercise referral and the SDT-based intervention at programme end. At 6-months, observed between arm and within intervention arm differences for indicators of emotional health, and the results of the process model, were in line with SDT. The challenges in optimising recruitment and implementation of SDT-based training in the context of health and leisure services are discussed
Scaling dependence on the fluid viscosity ratio in the selective withdrawal transition
In the selective withdrawal experiment fluid is withdrawn through a tube with
its tip suspended a distance S above a two-fluid interface. At sufficiently low
withdrawal rates, Q, the interface forms a steady state hump and only the upper
fluid is withdrawn. When Q is increased (or S decreased), the interface
undergoes a transition so that the lower fluid is entrained with the upper one,
forming a thin steady-state spout. Near this transition the hump curvature
becomes very large and displays power-law scaling behavior. This scaling allows
for steady-state hump profiles at different flow rates and tube heights to be
scaled onto a single similarity profile. I show that the scaling behavior is
independent of the viscosity ratio.Comment: 33 Pages, 61 figures, 1 tabl
Mydriatics: Drop the dose
This study investigated the difference in pupillary dilation between a normal dose and a substandard dose of a topical ophthalmic mydriatic agent, the combination of hydroxyamphetamine hydrobromide 1% and tropicamide 0.25% (Paremydâą solution). The manufacturer\u27s recommended dosage is 1-2 drops per eye. A typical opthalmic drop ranges in volume from 30 - 75. We hypothesized that a small, substandard dose of 10 will create a pupillary dilation clinically and statistically equivalent to that of the larger, standard dose of 30 in part due to the reflex tear response and increased lacrimal drainage. Our research found that the smaller dose of the mydriatic does indeed provide a clinically and statistically equivalent pupillary dilation to the larger dose. Clinically, the use of a reduced dose of a topical mydriatic will reduce the inherent risks and side effects to the patient (especially to the high-risk patient), while still allowing the eye care practitioner ample pupillary dilation to provide a quality dilated fundus examination
Amputee perception of prosthetic ankle stiffness during locomotion
Abstract
Background
Prosthetic feet are spring-like, and their stiffness critically affects the wearerâs stability, comfort, and energetic cost of walking. Despite the importance of stiffness in ambulation, the prescription process often entails testing a limited number of prostheses, which may result in patients receiving a foot with suboptimal mechanics. To understand the resolution with which prostheses should be individually optimized, we sought to characterize below-knee prosthesis usersâ psychophysical sensitivity to prosthesis stiffness.
Methods
We used a novel variable-stiffness ankle prosthesis to measure the repeatability of user-selected preferred stiffness, and implemented a psychophysical experiment to characterize the just noticeable difference of stiffness during locomotion.
Results
All eight subjects with below-knee amputation exhibited high repeatability in selecting their Preferred Stiffness (mean coefficient of variation: 14.2â±â1.7%) and were able to correctly identify a 7.7â±â1.3% change in ankle stiffness (with 75% accuracy).
Conclusions
This high sensitivity suggests prosthetic foot stiffness should be tuned with a high degree of precision on an individual basis. These results also highlight the need for a pairing of new robotic prescription tools and mechanical characterizations of prosthetic feet.https://deepblue.lib.umich.edu/bitstream/2027.42/146187/1/12984_2018_Article_432.pd
Exact Maximal Height Distribution of Fluctuating Interfaces
We present an exact solution for the distribution P(h_m,L) of the maximal
height h_m (measured with respect to the average spatial height) in the steady
state of a fluctuating Edwards-Wilkinson interface in a one dimensional system
of size L with both periodic and free boundary conditions. For the periodic
case, we show that P(h_m,L)=L^{-1/2}f(h_m L^{-1/2}) for all L where the
function f(x) is the Airy distribution function that describes the probability
density of the area under a Brownian excursion over a unit interval. For the
free boundary case, the same scaling holds but the scaling function is
different from that of the periodic case. Numerical simulations are in
excellent agreement with our analytical results. Our results provide an exactly
solvable case for the distribution of extremum of a set of strongly correlated
random variables.Comment: 4 pages revtex (two-column), 1 .eps figure include
- âŠ