Fundamental study in low-density gas dynamics Progress report, 1 Nov. 1968 - 30 Jun. 1969

Theoretical and experimental study of rarefied gas viscoseals in continuum to free molecular density range and speeds up to 30,000 rp

THREE-DIMENSIONAL COMPARISON OF SELECTED KINEMATICS BETWEEN MALE AND FEMALE INTERCOLLEGIATE JAVELIN THROWERS

The purpose of the study was to compare ROM, peak angular acceleration and percent throw values of peak angular acceleration of the upper arm, trunk, and pelvis segments, and elbow and knee joints between skilled male and female javelin throwers. Nine male and 11 female intercollegiate javelin throwers (n = 20) were videotaped using 2 120 Hz cameras. PEAK5 Motion Measurement System was used to analyze the data. Hotelling’s T2 tests revealed no significant differences (p > .01). However, females did appear to use the lower extremity differently by producing large amounts of pelvis ROM, pelvis peak angular acceleration, and knee extension peak angular accelerations. Both groups exhibited the proximal to distal sequencing of accelerations with the exception of upper arm internal rotation

A BIOMECHANICAL AND PHYSIOLOGICAL ANALYSIS OF EFFICIENCY AT DIFFERENT RUNNING PACES

The purpose of this study was to investigate the differences between several biomechanical and physiological variables associated with two different paces in treadmill running. The treadmill speed was adjusted to simulate an easy warm-up pace and a race pace for a 5000 m run. Another purpose was to study the contribution of both biomechanical and physiological variables toward total efficiency. The biomechanical variables included: (a) stride frequency, (b) stride length, (c) time of stride, and (d) percent of support. The physiological variables included: (a) heart rate, (b) R value, (c) V02, (d) percent of V02max, and (e) blood lactate. Nine intercollegiate distance runners from the north Texas area were filmed twice (5 min and 15 min) .from a sagittal view with a 16 mm high speed camera operating at 100 fps during two running paces. Joint segment markers were attached to the runners and one complete stride was digitized. The X/Y coordinates were used to determine the work per stride. Since physiological data were being collected simultaneously during the treadmill protocol, these were matched to the 5 min and 15 min film data intervals to determine total efficiency. A one-way repeated measures ANOVA was utilized with two paces and two times to investigate the biomechanical, physiological, and efficiency variables. Maximum experimentwise error control for Type I errors was necessary since ten dependent variables were utilized and the correlation matrix indicated that the data were nonorthogonal. A Bonferroni inequality test was also used and produced a modified alpha level of .005. No significant interactions for time by pace were found for any of the dependent variables. However, a trend does exist for several of the variables

Fundamental study in low-density gas dynamics Progress report, 1 Nov. 1967 - 1 Nov. 1968

Rarefied gas dynamics, nozzle flow, and filterin

A Description of Stroke Dynamics in 100 Meter Wheelchair Racing

Since wheelchair racing was introduced in the United States over thirty years ago, wheelchair sports have been experiencing a growing popularity. An ever increasing number of national, and international competitions are being held for the disabled athlete; and record times in racing events are being set on an almost routine basis. Much interest by coaches, athletes, and researchers exists in identifying optimal performance factors in wheelchair propulsion, Three major areas of interest relating to performance have been the topics of recent research, symposia, and conferenees. These include the following: (1) designing effective training programs; (2) improving chair design; and (3) optimizing technique. Elite disabled athletes are being profiled by researchers from both physiological and biomechanical perspectives. All wheelchair users stand to benefit from wheelchair sports and research. Where many everyday chair users once were in a heavy, awkward «hospital-type» chair that fitted no one and certainly wasn't designed for sports use, now light weight, easily maneuverable chairs are in use. As equipment is improved and propulsion techniques become more efficient, all chair users can benefit from such knowledge. The United States Olympic Committee sponsored their first Sports Medieine and Sports Science Conference for the Disabled Athlete in the United States in March of 1987. This conference provided the opportunity for coaches, athletes, researchers, and other persons interested in sports for the disabled athlete to come together to share knowledge and ideas, and to examine the unique needs of the disabled performer. While physical limitations may influence the disabled athlete's perfomance, today's athletes are vitally interested in learning how to maximize their individual physical abilities. Although the major thrust of a great many of the research studies investigating wheelchair athletes has often been of a physiologic nature, a growing body of biomechanic research on wheelchair propulsion has been identified (Ridgwaw, Pope & Wilkerson, 1987; Siler, Martin & Mungiole, 1987; Higgs, 1986; Sanderson & Sommer, 1985; Cerquiglini, Figura, Marchetti & Ricci, 1981; King, 1981; and Perry, 1981). Many of these investigations have included small sample sizes, have been limited to male subjects, and have included relatively few classes of wheelchair athletes. Additionally, few have studied the elite wheelchair athlete during commpetition. The purpose of this study was to develop a kinematic model of wheelchair propulsion during 100-meter racing as performed by three classes of elite male wheelchair athletes

Development of a validation model for the defense meteorological satellite program's special sensor microwave imager

The Defence Meteorological Space Program's (DMSP) Special Sensor Microwave/Imager (SSM/I), an operational wind speed algorithm was developed. The algorithm is based on the D-matrix approach which seeks a linear relationship between measured SSM/I brightness temperatures and environmental parameters. D-matrix performance was validated by comparing algorithm derived wind speeds with near-simultaneous and co-located measurements made by off-shore ocean buoys. Other topics include error budget modeling, alternate wind speed algorithms, and D-matrix performance with one or more inoperative SSM/I channels

Unchanged content of oxidative enzymes in fast-twitch muscle fibers and V˙O2 kinetics after intensified training in trained cyclists.

PublishedJournal ArticleThe present study examined if high intensity training (HIT) could increase the expression of oxidative enzymes in fast-twitch muscle fibers causing a faster oxygen uptake (V˙O2) response during intense (INT), but not moderate (MOD), exercise and reduce the V˙O2 slow component and muscle metabolic perturbation during INT. Pulmonary V˙O2 kinetics was determined in eight trained male cyclists (V˙O2-max: 59 ± 4 (means ± SD) mL min(-1) kg(-1)) during MOD (205 ± 12 W ~65% V˙O2-max) and INT (286 ± 17 W ~85% V˙O2-max) exercise before and after a 7-week HIT period (30-sec sprints and 4-min intervals) with a 50% reduction in volume. Both before and after HIT the content in fast-twitch fibers of CS (P < 0.05) and COX-4 (P < 0.01) was lower, whereas PFK was higher (P < 0.001) than in slow-twitch fibers. Content of CS, COX-4, and PFK in homogenate and fast-twitch fibers was unchanged with HIT. Maximal activity (μmol g DW(-1) min(-1)) of CS (56 ± 8 post-HIT vs. 59 ± 10 pre-HIT), HAD (27 ± 6 vs. 29 ± 3) and PFK (340 ± 69 vs. 318 ± 105) and the capillary to fiber ratio (2.30 ± 0.16 vs. 2.38 ± 0.20) was unaltered following HIT. V˙O2 kinetics was unchanged with HIT and the speed of the primary response did not differ between MOD and INT. Muscle creatine phosphate was lower (42 ± 15 vs. 66 ± 17 mmol kg DW(-1)) and muscle lactate was higher (40 ± 18 vs. 14 ± 5 mmol kg DW(-1)) at 6 min of INT (P < 0.05) after compared to before HIT. A period of intensified training with a volume reduction did not increase the content of oxidative enzymes in fast-twitch fibers, and did not change V˙O2 kinetics.The study was supported by Team Danmark (Danish Elite Sport Organization)

A pulsed, mono-energetic and angular-selective UV photo-electron source for the commissioning of the KATRIN experiment

The KATRIN experiment aims to determine the neutrino mass scale with a sensitivity of 200 meV/c^2 (90% C.L.) by a precision measurement of the shape of the tritium $\beta$-spectrum in the endpoint region. The energy analysis of the decay electrons is achieved by a MAC-E filter spectrometer. To determine the transmission properties of the KATRIN main spectrometer, a mono-energetic and angular-selective electron source has been developed. In preparation for the second commissioning phase of the main spectrometer, a measurement phase was carried out at the KATRIN monitor spectrometer where the device was operated in a MAC-E filter setup for testing. The results of these measurements are compared with simulations using the particle-tracking software "Kassiopeia", which was developed in the KATRIN collaboration over recent years.Comment: 19 pages, 16 figures, submitted to European Physical Journal

PlantGDB: a resource for comparative plant genomics

PlantGDB (http://www.plantgdb.org/) is a genomics database encompassing sequence data for green plants (Viridiplantae). PlantGDB provides annotated transcript assemblies for >100 plant species, with transcripts mapped to their cognate genomic context where available, integrated with a variety of sequence analysis tools and web services. For 14 plant species with emerging or complete genome sequence, PlantGDB's genome browsers (xGDB) serve as a graphical interface for viewing, evaluating and annotating transcript and protein alignments to chromosome or bacterial artificial chromosome (BAC)-based genome assemblies. Annotation is facilitated by the integrated yrGATE module for community curation of gene models. Novel web services at PlantGDB include Tracembler, an iterative alignment tool that generates contigs from GenBank trace file data and BioExtract Server, a web-based server for executing custom sequence analysis workflows. PlantGDB also hosts a plant genomics research outreach portal (PGROP) that facilitates access to a large number of resources for research and training

Assessing the Need and Receptivity for an Integrated Healthy Sexual and Dating Relationships Intervention for Community College Students

Background: In emerging adulthood, youth often become involved in more serious romantic relationships. However, many lack the skills to avoid an unplanned pregnancy or sexually transmitted infection (STI), and to ensure a healthy dating relationship. Community college students serve nearly half of all undergraduate students in the United States; yet, community colleges typically lack resources for sexual health promotion. Purpose: To assess the need and receptivity for a web-based integrated healthy sexual and dating relationships intervention among community college students. Methods: In summer 2016, we partnered with three community colleges in South Central Texas to conduct an online survey of students’ sexual behaviors and dating relationships, and usability testing of activities from an integrated, web-based healthy sexual and dating relationship intervention. Results: Online survey participants (n=271) were 70% female, 38% Hispanic, 24% White, 17% Black, and 16% Asian; 20% self-identified as sexual minority; mean age was 20.8 years (SD = 2.05). Participants reported high rates of sexual risk behavior including sex without a condom or an effective birth control method, low use of long-acting reversible contraception, frequent use of emergency contraception, and low use of dual protection to prevent pregnancy and sexually transmitted infections. Two-thirds reported experiencing any type of dating violence perpetration or victimization in the past year. Usability testing participants (n=14) were 86% female, 42% Hispanic, 50% Asian/Pacific Islander, 14% Black, and 7% White; 71% were sexually experienced; mean age was 20.7 years (SD = 1.64). The web-based activities were highly rated in terms of usability parameters, and positively impacted short-term psychosocial outcomes related to condom use, accessing contraceptive health services, and constructive interpersonal conflict resolution. Conclusion: Findings underscore the high need and receptivity for an integrated healthy sexual and dating relationship web-based intervention among community college students, an understudied subgroup of youth in emerging adulthood