Comparison of the performances of male and female armed services recruits undergoing sports vision testing

Research has shown that a strong correlation exists between vision and performance. In the sporting environment, it is believed that athletes perform better than non-athletes and males perform better than females. In this study we used sports vision to compare performance between males and females. One hundred and thirty male and one hundred female armed service recruits were tested, using techniques of visualization, eye-hand coordination, focusing, sequencing, tracking and reflexes. Previous research has shown that the difference in performance in both males and females is the result of brain lateralization, test familiarity and nerve conduction velocity in the brain. This was, however, not reflected in the study. Results showed a significant difference in performance with regard to visualization (p=0.006), tracking (p=0.048), reflexes (p=0.0001) and sequencing (p=0.046). The increased performance might become more evident with repetition of tests. Future research should therefore investigate the exact physiological mechanisms and interrelation of variables thought to affect performance.http://www.ajol.info/journal_index.php?jid=153&ab=ajpher

Cardiovascular health screening among South African students

Stress is an unavoidable part of everyday life due to the demands and stressors associated with modern lifestyle. Health risks provoked by this increasingly prevalent condition lead to cardiovascular disease, which ultimately results in a poor health status. Studies have confirmed that there is a correlation between a person’s lifestyle and stress levels: sedentary lifestyles increase the risk of developing various cardiovascular conditions. Improved physical fitness is one of the lifestyle modifications proven to benefit heart health by reducing the effects of stress and its associated threats. The purpose of this study was to compare the heart health of subjects from two further education and training institutes. Institution 1 is a traditional tertiary institution that focuses on lectures, while Institution 2 provides an organised, daily physical training programme in addition to its academic programme. Subjects underwent a non-invasive ViportTM test which measures the cardio stress index (CSI), heart rate (HR), and QRS duration. Additional variables measured included: age, gender, perceived stress level, systolic and diastolic blood pressure and body mass index. Results obtained from the study indicate that students from Institution 1 (n=158) had significantly higher readings (p<0.001) than those from Institution 2 (n=128) on CSI and HR, but significantly lower readings on blood pressure (systolic and diastolic). In theory, this finding may be attributed to the fact that individuals from Institution 1 (training population) follow a set daily physical routine which improves their heart health and decreases stress- related risk.http://www.ajol.info/journal_index.php?jid=153&ab=ajpher

The effect of sport specific exercises on the visual skills of rugby players

INTRODUCTION: Visual performance is an important factor in sport excellence. Visual involvement in a sport varies according to environmental demands associated with that sport. These environmental demands are matched by a task specific motor response. The purpose of this study was to determine if sport specific exercises will improve the visual performance of male rugby players, in order to achieve maximal results on the sports field. MATERIALS AND METHODS: Twenty six adult male rugby players, aged 16-22, were chosen as subjects. In order to evaluate the effect of sport specific exercises on visual skills, a pre-test - post-test experimental group design was adopted for the study. RESULTS: Significant differences (p≤0.05) were seen in the focussing, tracking, vergence, sequencing, eye-hand coordination and visualisation components Discussion & Conclusions: Sport specific exercises improved visual skills in rugby players which may provide them with an advantage over their opponents. This study suggests that these training programs and participation in regular on-line EyeDrills sports vision exercises (www.eyedrills.co.za) aimed at improving the athlete’s visual co-ordination, concentration, focus, hand-eye co-ordination, anticipation and motor response should be incorpotated in the rugby players exercise regime. Keywords— Rugby players, sport specific exercises, visual skillshttp://www.waset.org/journals/waset/v76.ph

A Study of Cosmic Ray Secondaries Induced by the Mir Space Station Using AMS-01

The Alpha Magnetic Spectrometer (AMS-02) is a high energy particle physics experiment that will study cosmic rays in the $\sim 100 \mathrm{MeV}$ to $1 \mathrm{TeV}$ range and will be installed on the International Space Station (ISS) for at least 3 years. A first version of AMS-02, AMS-01, flew aboard the space shuttle \emph{Discovery} from June 2 to June 12, 1998, and collected $10^8$ cosmic ray triggers. Part of the \emph{Mir} space station was within the AMS-01 field of view during the four day \emph{Mir} docking phase of this flight. We have reconstructed an image of this part of the \emph{Mir} space station using secondary $\pi^-$ and $\mu^-$ emissions from primary cosmic rays interacting with \emph{Mir}. This is the first time this reconstruction was performed in AMS-01, and it is important for understanding potential backgrounds during the 3 year AMS-02 mission.Comment: To be submitted to NIM B Added material requested by referee. Minor stylistic and grammer change

Detecting life outside our solar system with a large high-contrast-imaging mission

In this White Paper, which was submitted in response to the European Space Agency (ESA) Voyage 2050 Call, we recommend the ESA plays a proactive role in developing a global collaborative effort to construct a large high-contrast imaging space telescope, e.g. as currently under study by NASA. Such a mission will be needed to characterize a sizable sample of temperate Earth-like planets in the habitable zones of nearby Sun-like stars and to search for extraterrestrial biological activity. We provide an overview of relevant European expertise, and advocate ESA to start a technology development program towards detecting life outside the Solar System.Publisher PDFPeer reviewe

Dust in Supernovae and Supernova Remnants I : Formation Scenarios

Supernovae are considered as prime sources of dust in space. Observations of local supernovae over the past couple of decades have detected the presence of dust in supernova ejecta. The reddening of the high redshift quasars also indicate the presence of large masses of dust in early galaxies. Considering the top heavy IMF in the early galaxies, supernovae are assumed to be the major contributor to these large amounts of dust. However, the composition and morphology of dust grains formed in a supernova ejecta is yet to be understood with clarity. Moreover, the dust masses inferred from observations in mid-infrared and submillimeter wavelength regimes differ by two orders of magnitude or more. Therefore, the mechanism responsible for the synthesis of molecules and dust in such environments plays a crucial role in studying the evolution of cosmic dust in galaxies. This review summarises our current knowledge of dust formation in supernova ejecta and tries to quantify the role of supernovae as dust producers in a galaxy.Peer reviewe

Adult soft tissue sarcomas of the head and neck treated by radiation and surgery or radiation alone: Patterns of failure and prognostic factors

Purpose : To analyze our experience treating soft tissue sarcomas of the head and neck in adults, and to identify patterns of failure and prognostic factors. Methods and Materials : The recors of 57 patients with Stage M0 disease treated by radiation with or without surgery between 1972 and 1993 were reviewed. Medial follow-up time was 4.3 years (range, 1.1–16.8 years). A group of potential prognostic factors was evaluated, including age diagnosis, sex, initial tumor presentation (primary vs. recurrent), grade, T-stage, direct tumor extension, tumor depth, duration of treatment, and radiation dose. Results : The subset of angiosarcomas (11 of 57 patients) had a considerably adverse effect on treatment outcome for the total group of sarcomas, with actuarial 5-year overall survival (OS), locoregional control (LRC), and freedom from distant metastasis (FDM) rates being 31%, 24%, and 42%, respectively. In contrast, for the remaining 46 patients with other histopathological tumor types, OS, LRC, and FDM rates were significantly higher (74%, 69%, and 83%, respectively). For this group of patients, significant prognostic factors identified by uni- and multivariate analysis included tumor grade as a predictor of OS and T-stage 3s a predictor of LRC ( p ≤ 0.050). Those patients who experienced a locoregional recurrence were at a significantly increased risk of dying ( p = 0.004 in a multivariate model). All 17 patients withou direct tumor extension to neurovascular structures, bone, contiguous organs, or skin remained free from distant failure. In contrast, 27% of 29 patients with direct extension had developed distant metastases at 5 years. In multivariate analysis, the absence of direct extension was a positive predictor of FDM ( p = 0.007) and of OS ( p = 0.034). Conclusions : 1) Angiosarcomas of the head and neck have a considerably poorer prognosis than other soft tissue sarcomas of this site. 2) In addition to tumor grade and size, direct tumor extension may be a useful additional staging parameter. 3) High rates of locoregional failure in the head and neck area, a potential cause of morbidity and death, indicate a need for improved treatment strategies