Scanning electron and atomic force microscopic analysis of erythrocytes in a cohort of atopic asthma patients - a pilot study

DATA AVAILABILITY STATEMENT : Availability of data and material; Data and material are available upon request.BACKGROUND : Non-communicable diseases are often associated with chronic inflammation, placing patients suffering from these conditions at a higher risk of thrombosis and other complications. The pathophysiology of asthma and/or atopic asthma is also linked to chronic inflammation, which consequently may alter blood parameters including erythrocyte structure and function. METHODOLOGY : The objective of this study was to evaluate differences in erythrocytes between patients with atopic asthma (n = 30) and healthy individuals (n = 30) by evaluating routine haematological parameters; structures and axial ratios of erythrocytes using light microscopy; erythrocyte membrane elasticity using atomic force microscopy; and erythrocyte ultrastructure using scanning electron microscopy. RESULTS : The haematological findings of healthy participants and patients suffering from asthma were within normal clinical ranges together with significantly higher levels of circulating monocytes (p = 0.0066), erythrocytes (p = 0.0004), haemoglobin (p = 0.0057), and haematocrit (p = 0.0049) in asthma patients. The analysis of eosin-stained erythrocytes by light microscopy showed more echinocytes, acanthocytes, and ovalocytes compared to controls and a significant difference in axial ratios (p < 0.0001). Atomic force microscopy findings showed reduced erythrocyte membrane elasticity in asthmatic erythrocytes (p = 0.001). Ultrastructural differences in erythrocytes were visible in the asthma group compared to controls. CONCLUSION : Altered erythrocyte ultrastructural morphology and a significant change in the haematological profile are evident in atopic asthma and may influence common complications associated with asthma. The impact of these changes on the physiological mechanisms of coagulation and the pathophysiology of asthma needs to be further elucidated.https://www.mdpi.com/journal/hematohj2024PhysiologySDG-03:Good heatlh and well-bein

The influence of probiotic supplementation on selected athletic performance-related blood markers in men

It has been speculated that probiotics can improve athletic performance. Significant increases in haemoglobin concentration and oxygen consumption have also been shown to follow the ingestion of lactic acid bacteria in athletes. The aim of this study was to determine whether the administration of commercially prepared probiotics could influence haemoglobin concentration and other haematological parameters in moderately active males. Fifty healthy, moderately active male volunteers were divided into two groups (Test Group and Control Group). A randomized, double-blind, placebo-controlled, pre-test/post-test, group comparison study was done. The study showed no significant differences (p≥0.05) between the two groups on any of the dependent measurements. There were statistically significant changes (p≤0.05) between pre- and post-test results within the two groups. These changes were within physiological limits. Sodium increased significantly (p=0,001) from 139.29 mmol/L to 140.96 mmol/L in the Control Group. In the Test Group sodium increased significantly (p=0,035) from 139.60 mmol/L to 140.90 mmol/L, and potassium decreased (p=0.010) from 4.67 mmol/L to 4.44 mmol/L. Study results thus indicated that the ingestion of a lactic acid bacteria preparation for 42 days did not increase the haemoglobin concentration in moderately active males.http://www.ajol.info/journal_index.php?jid=153&ab=ajpher

Hydrogen Epoch of Reionization Array (HERA)

The Hydrogen Epoch of Reionization Array (HERA) is a staged experiment to measure 21 cm emission from the primordial intergalactic medium (IGM) throughout cosmic reionization ($z=6-12$), and to explore earlier epochs of our Cosmic Dawn ($z\sim30$). During these epochs, early stars and black holes heated and ionized the IGM, introducing fluctuations in 21 cm emission. HERA is designed to characterize the evolution of the 21 cm power spectrum to constrain the timing and morphology of reionization, the properties of the first galaxies, the evolution of large-scale structure, and the early sources of heating. The full HERA instrument will be a 350-element interferometer in South Africa consisting of 14-m parabolic dishes observing from 50 to 250 MHz. Currently, 19 dishes have been deployed on site and the next 18 are under construction. HERA has been designated as an SKA Precursor instrument. In this paper, we summarize HERA's scientific context and provide forecasts for its key science results. After reviewing the current state of the art in foreground mitigation, we use the delay-spectrum technique to motivate high-level performance requirements for the HERA instrument. Next, we present the HERA instrument design, along with the subsystem specifications that ensure that HERA meets its performance requirements. Finally, we summarize the schedule and status of the project. We conclude by suggesting that, given the realities of foreground contamination, current-generation 21 cm instruments are approaching their sensitivity limits. HERA is designed to bring both the sensitivity and the precision to deliver its primary science on the basis of proven foreground filtering techniques, while developing new subtraction techniques to unlock new capabilities. The result will be a major step toward realizing the widely recognized scientific potential of 21 cm cosmology.Comment: 26 pages, 24 figures, 2 table

Initial assessment of well-being in South African armed services personnel

As professionals in law enforcement and defence (armed services) function under high pressure, the maintenance of overall health should be emphasized and closely monitored in training facilities. The aim of this research was to assess current health status and risk factors of the members of three armed service training facilities. This represents the first step in an integrated approach toward health maintenance in this important sector. The sample consisted of 323 members from three different armed service training facilities in South Africa. The subjects completed a questionnaire on health history and coping with stress. Heart health, body composition, general fitness and co-ordination were then examined. The mean age of the sample was 38.08 years (SD=8.81). The mean blood pressure readings were pre-hypertensive (Systolic 127.4mmHg, SD=16.67; Diastolic 82.74mmHg, SD=10.94) and the mean BMI was in the overweight category (27.97kg/m2, SD=8.81). The percentage (more than 40 %) of subjects that require physical fitness intervention reflects an urgent need for effective implementation of wellness programmes in this sector.http://www.ajol.info/journal_index.php?jid=153&ab=ajpher

Evaluation of visual skills in sedentary and active work environments

The two fundamental categories of vision include visual-perceptual and visual-motor skills. Visual-motor skills encompass three essential ocular motor skills, namely focusing, eye-hand coordination and tracking. The aspects of the visual perceptual process include visual memory and visualization. This study aims to determine whether there is a difference in the visual performance of individuals exposed to a sedentary work environment and those exposed to an active work environment. The participants consisted of military recruits, who underwent a 12 week intense training regimen, and second year university students, who were subjected to a battery of vision testing to determine their visual performance. It was hypothesized that training recruits will possess superior visual skills in comparison to university students. The results indicate that training recruits possess superior skills in eye-hand coordination and visualization, while students showed enhanced tracking and sequencing skills. Cardio stress indices and blood pressures were tested to determine the heart health of the subjects and whether these factors influence visual attributes. Although not significant, the results indicate a decrease in cardio stress index in training recruits although their blood pressures were higher than those of students. The results concur with previous studies, which have shown that individuals exposed to physical activity, even for a short period of time, tend to acquire superior visual skills. However, the skills are honed according to the field of expertise due to the transfer effect that occurs in the brain. The findings of the study support as well as contradict evidence regarding sports vision testing and training, thus further investigation is required to elucidate the controversy regarding vision testing.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

The correlation between the health-related fitness of healthy participants measured at home as opposed to fitness measured by sport scientists in a laboratory

BACKGROUND : Fitness is defined in the health context as a state of good health or physical condition, primarily as a result of exercise and proper nutrition. Conventional methods of measuring fitness are expensive, time consuming and require specialised methods. There is a need for noninvasive, fast methods of assessing health-related fitness and activity in athlete and non-athlete populations. The aim of this study was to establish any correlation between participants’ self-assessed health-related fitness (HRF) index and the HRF index determined by sports scientists, as well as the laboratory-assessed HRF index and maximum oxygen uptake (VO2max) determined by sports scientists via direct methods in a laboratory, and finally, to determine any potential correlation between an activity-recall questionnaire (Kasari) and VO2max. METHOD : The participants consisted of 169 male and female volunteers between the ages of 18 and 55 years, taking neither supplements nor medication. The University of Pretoria’s HRF index protocol was first carried out by participants on their own at home, and then in the laboratory under the supervision of sport scientists. The complete datasets of 150 participants were statistically analysed to establish correlations. RESULTS : The results indicated highly significant and substantial correlations (ρ = 0.696, p < 0.001) between the participants’ self-assessed HRF index and measurements by the sports scientists. There were moderate correlations between the laboratoryassessed HRF index and the direct VO2max (ρ = 0 512, p < 0.005), as well as the indirect VO2max (ρ = 0.588; p < 0.001). A significant correlation was found between the self-assessed HRF index and the indirect VO2max (ρ = 0.454; p < 0.001). The Kasari questionnaire correlated only weakly with the indirect VO2max (ρ = 0.278, p < 0.002) and not at all with the direct VO2max (ρ = 0.072, p = 0.731). CONCLUSION : Indications are that this test protocol may be conducted at home by individuals, without supervision, to determine exercise ability or fitness, or to monitor changes in physical fitness, thereby limiting expenses and costs.Momentum Interactivehttp://www.safpj.co.za/index.php/safpjhb201

Optimizing Sparse RFI Prediction using Deep Learning

Radio Frequency Interference (RFI) is an ever-present limiting factor among radio telescopes even in the most remote observing locations. When looking to retain the maximum amount of sensitivity and reduce contamination for Epoch of Reionization studies, the identification and removal of RFI is especially important. In addition to improved RFI identification, we must also take into account computational efficiency of the RFI-Identification algorithm as radio interferometer arrays such as the Hydrogen Epoch of Reionization Array grow larger in number of receivers. To address this, we present a Deep Fully Convolutional Neural Network (DFCN) that is comprehensive in its use of interferometric data, where both amplitude and phase information are used jointly for identifying RFI. We train the network using simulated HERA visibilities containing mock RFI, yielding a known "ground truth" dataset for evaluating the accuracy of various RFI algorithms. Evaluation of the DFCN model is performed on observations from the 67 dish build-out, HERA-67, and achieves a data throughput of 1.6$\times 10^{5}$ HERA time-ordered 1024 channeled visibilities per hour per GPU. We determine that relative to an amplitude only network including visibility phase adds important adjacent time-frequency context which increases discrimination between RFI and Non-RFI. The inclusion of phase when predicting achieves a Recall of 0.81, Precision of 0.58, and $F_{2}$ score of 0.75 as applied to our HERA-67 observations.Comment: 11 pages, 7 figure

HI 21cm Cosmology and the Bi-spectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays

New massively redundant low frequency arrays allow for a novel investigation of closure relations in interferometry. We employ commissioning data from the Hydrogen Epoch of Reionization Array to investigate closure quantities in this densely packed grid array of 14m antennas operating at 100 MHz to 200 MHz. We investigate techniques that utilize closure phase spectra for redundant triads to estimate departures from redundancy for redundant baseline visibilities. We find a median absolute deviation from redundancy in closure phase across the observed frequency range of about 4.5deg. This value translates into a non-redundancy per visibility phase of about 2.6deg, using prototype electronics. The median absolute deviations from redundancy decrease with longer baselines. We show that closure phase spectra can be used to identify ill-behaved antennas in the array, independent of calibration. We investigate the temporal behavior of closure spectra. The Allan variance increases after a one minute stride time, due to passage of the sky through the primary beam of the transit telescope. However, the closure spectra repeat to well within the noise per measurement at corresponding local sidereal times (LST) from day to day. In future papers in this series we will develop the technique of using closure phase spectra in the search for the HI 21cm signal from cosmic reionization.Comment: 32 pages. 11 figures. Accepted to Radio Scienc