248 research outputs found
Developing methods for antibody-mediated enrichment and capture of spermatozoa from complex cell mixtures for forensics applications
Cases of sexual assault have steadily increased over the past years. Sexual assault samples are complex with vaginal epithelial cells as the main contributor to the sample, while spermatozoa are vast in number. There a variety of techniques such as differential extraction and laser capture microdissection that exist to isolate and capture spermatozoa for DNA profiling. These methods are tedious and are not always efficient. Anti-sperm antibodies can be used to target spermatozoa by binding to antigens localised on the surface of the acrosome. This study tested the binding capacity of a variety of anti-sperm antibodies to fresh and aged spermatozoa. The binding ability of the α-SPAM1 primary antibody to spermatozoa eluted from Copan rayon swabs was assessed to evaluate that the number of spermatozoa stained was sufficient for STR analysis. This study showed that α-SPAM1 and α-SPACA1 stained more than >30% of cells in fresh and aged spermatozoa. This study found that 39% of aged spermatozoa were stained with a combination of α-SPAM1 and α-SPACA1. It was found that Copan rayon swabs were efficient at absorbing spermatozoa but only released <50% of cells. Copan rayon swabs retain 33% of initial spermatozoa consumed. The study found that despite the high retention capacity of Copan rayon swabs, sufficient numbers of spermatozoa were eluted and stained with α-SPAM1 at levels compatible with DNA techniques such as STR analysis. In conclusion, this study shows that in future studies, α-SPAM1 and α-SPACA1 could be used to in conjunction with immunomagnetic beads to extract spermatozoa from sexual assault samples
The mechanics of the table contact phase of gymnastics vaulting
A computer simulation model of the table contact phase of gymnastics vaulting was developed to gain an understanding of the mechanics of this phase of the vault. The model incorporated a gymnast and a vaulting table, and used a novel two-state contact phase representation to simulate the interaction between these two bodies during the table contact phase. The gymnast was modelled in planar form using seven segments, with torque generators acting at the wrist, shoulder, hip and knee joints. The model also allowed for shoulder retraction and protraction, displacement of the glenohumeral joint centre and flexion/extension of the fingers. The table was modelled as a single rigid body that could rotate. The model was personalised to an elite gymnast so that simulation outputs could be compared with the gymnast's performance. Kinematic data of vaulting performances were obtained using a optoelectronic motion capture system. Maximal voluntary joint torques were also measured using an isovelocity dynamometer, and a torque - angle - angular velocity relationship was used to relate joint torques to joint angles and angular velocities. A set of model system parameters was determined using a gymnast-specific angle-driven model by matching four simulations to their respective performances concurrently. The resulting parameters were evaluated using two independent trials, and found to be applicable to handspring entry vaults. The torque-driven model was successfully evaluated, and shown to produce realistic movements, with mean overall differences between simulations and recorded performances of 2.5% and 8.6% for two different handspring entry vaults. The model was applied to further understanding of the mechanics of the table contact phase of gymnastics vaulting. Optimisation showed that there was limited potential (1.3%) for the gymnast to improve performance through technique changes during the table contact phase. However, with additional changes in configuration at table contact post-flight rotation could be increased by 9.8% and post-flight height could be increased by 0.14m. Angular momentum was found to always decrease during the table contact phase of the vault, although the reductions were less when maximising post-flight rotation
Stereotypes of African American Female Athletes and Their Impact
“Neither the NCAA nor others have found it necessary to address the inequity that exists between European American and African American female athletes concerning stereotypes.
Optimal technique for maximal forward rotating vaults in men's gymnastics
In vaulting a gymnast must generate sufficient linear and angular momentum during the approach and table contact to complete the rotational requirements in the post-flight phase. This study investigated the optimisation of table touchdown conditions and table contact technique for the maximisation of rotation potential for forwards rotating vaults. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a handspring double somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to maximise post-flight rotation potential (the product of angular momentum and flight time) for a forwards rotating vault. It was found that the maximised rotation potential was sufficient to produce a handspring double piked somersault vault. The corresponding optimal touchdown configuration exhibited hip flexion in contrast to the hyperextended configuration required for maximal height. Increasing touchdown velocity and angular momentum lead to additional post-flight rotation potential. By increasing the horizontal velocity at table touchdown, within limits obtained from recorded performances, the handspring double somersault tucked with one and a half twists, and the handspring triple somersault tucked became theoretically possible
Evaluation of respiratory function using blood gas parameters in Yucatan minipigs following Spinal Cord Injury
There are approximately 17,810 new spinal cord injuries (SCI) in the U.S. each year [1]. Physical damage to the spinal cord has the potential to interfere with normal motor, sensory, and/or autonomic function, such as impairment of the respiratory system. In fact, respiratory insufficiency is the number one cause of mortality and morbidity after SCI. The more rostral the injury, the more likely there will be disruption to normal ventilation (generally rostral to T6) [2]. To conduct relevant preclinical research, it has been shown that large animal models, such as the Yucatan minipig, have a better success rate of translating to the clinical setting when compared to rodent or other small animal models [3]. While trying to optimize this animal model to specifically target deficits in mobility, it was important to narrow the injury site, which would isolate mobility and not affect the respiratory system. In this study, 18 Yucatan minipigs were randomized into groups of 6 and received either a mild, moderate, or severe level of a T9/T10 SCI. Blood gases PO2, PCO2, HCO3, and pH were recorded hourly prior to, during, and immediately post injury to evaluate stability of the animal during anesthesia, as well as closely monitor respiratory function following SCI. Parameters were monitored one hour prior to anesthetic induction and up to 4 hours post anesthesia recovery. None of the groups showed significant deficits in respiratory function post-injury. It was concluded that a T9/T10 injury could be used to isolate motor function independent of respiratory deficits
A comparison of Coulomb and pseudo-Coulomb friction implementations: application to the table contact phase of gymnastics vaulting
In the table contact phase of gymnastics vaulting both dynamic and static friction act. The purpose of this study was to develop a method of simulating Coulomb friction that incorporated both dynamic and static phases and to compare the results with those obtained using a pseudo-Coulomb implementation of friction when applied to the table contact phase of gymnastics vaulting. Kinematic data were obtained from an elite level gymnast performing handspring straight somersault vaults using a Vicon optoelectronic motion capture system. An angle-driven computer model of vaulting that simulated the interaction between a seven-segment gymnast and a single-segment vaulting table during the table contact phase of the vault was developed. Both dynamic and static friction were incorporated within the model by switching between two implementations of the tangential frictional force. Two vaulting trials were used to determine the model parameters by using a genetic algorithm to match simulations to recorded performances. A third independent trial was used to evaluate the model and close agreement was found between the simulation and the recorded performance with an overall difference of 13.5%. The two-state simulation model was found to be capable of replicating performance at take-off and also of replicating key contact phase features such as the normal and tangential motion of the hands. The results of the two-state model were compared to those using a pseudo-Coulomb friction implementation within the simulation model. The two-state model achieved similar overall results to those of the pseudo-Coulomb model but obtained solutions more rapidly
The influence of touchdown conditions and contact phase technique on post-flight height in the straight handspring somersault vault
In vaulting the gymnast must generate sufficient linear and angular momentum during the approach and table contact in order to complete the rotational requirements in the post-flight phase. This study investigated the effects of touchdown conditions and contact technique on peak post-flight height of a straight handspring somersault vault. A planar seven-segment torque-driven computer simulation model of the contact phase in vaulting was evaluated by varying joint torque activation time histories to match three performances of a straight handspring somersault vault by an elite gymnast. The closest matching simulation was used as a starting point to optimise peak post-flight height of the mass centre for a straight handspring somersault. It was found that optimising either the touchdown conditions or the contact technique increased post-flight height by 0.1 m whereas optimising both together increased post-flight height by 0.4 m above that of a simulation matching the recorded performance. Thus touchdown technique and contact technique make similar contributions to post-flight height in the straight handspring somersault vault. Increasing touchdown velocity and angular momentum lead to additional post-flight height although there was a critical value of vertical touchdown velocity beyond which post-flight height decreased
What is the role of culture, diversity, and community engagement in transdisciplinary translational science?
Concepts of culture and diversity are necessary considerations in the scientific application of theory generation and developmental processes of preventive interventions; yet, culture and/or diversity are often overlooked until later stages (e.g., adaptation [T3] and dissemination [T4]) of the translational science process. Here, we present a conceptual framework focused on the seamless incorporation of culture and diversity throughout the various stages of the translational science process (T1-T5). Informed by a community-engaged research approach, this framework guides integration of cultural and diversity considerations at each phase with emphasis on the importance and value of "citizen scientists" being research partners to promote ecological validity. The integrated partnership covers the first phase of intervention development through final phases that ultimately facilitate more global, universal translation of changes in attitudes, norms, and systems. Our comprehensive model for incorporating culture and diversity into translational research provides a basis for further discussion and translational science development
The process of setting micronutrient recommendations: a cross-European comparison of nutrition-related scientific advisory bodies
Copyright @ The Authors 2010Objective: To examine the workings of the nutrition-related scientific advisory bodies in Europe, paying particular attention to the internal and external contexts within which they operate. Design: Desk research based on two data collection strategies: a questionnaire completed by key informants in the field of micronutrient recommendations and a case study that focused on mandatory folic acid (FA) fortification. Setting: Questionnaire-based data were collected across thirty-five European countries. The FA fortification case study was conducted in the UK, Norway, Denmark, Germany, Spain, Czech Republic and Hungary. Results: Varied bodies are responsible for setting micronutrient recommendations, each with different statutory and legal models of operation. Transparency is highest where there are standing scientific advisory committees (SAC). Where the standing SAC is created, the range of expertise and the terms of reference for the SAC are determined by the government. Where there is no dedicated SAC, the impetus for the development of micronutrient recommendations and the associated policies comes from interested specialists in the area. This is typically linked with an ad hoc selection of a problem area to consider, lack of openness and transparency in the decisions and over-reliance on international recommendations. Conclusions: Even when there is consensus about the science behind micronutrient recommendations, there is a range of other influences that will affect decisions about the policy approaches to nutrition-related public health. This indicates the need to document the evidence that is drawn upon in the decisions about nutrition policy related to micronutrient intake.This work has been carried out within the EURRECA Network of Excellence (www.eurreca.org) which is financially supported by the Commission of the European Communities, specific Research, Technology and Development (RTD) Programme Quality of Life and Management of Living Resources, within the Sixth Framework Programme, contract no. 036196
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