Enhancing the Experience of International Doctoral Researchers - Key Messages

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Hypoxic repeat sprint training improves rugby player's repeated sprint but not endurance performance

This study aims to investigate the performance changes in 19 well-trained male rugby players after repeat-sprint training (six sessions of four sets of 5 × 5 s sprints with 25 s and 5 min of active recovery between reps and sets, respectively) in either normobaric hypoxia (HYP; n = 9; F₁O₂ = 14.5%) or normobaric normoxia (NORM; n = 10; F₁O₂ = 20.9%). Three weeks after the intervention, 2 additional repeat-sprint training sessions in hypoxia (F₁O₂ = 14.5%) was investigated in both groups to gauge the efficacy of using "top-up" sessions for previously hypoxic-trained subjects and whether a small hypoxic dose would be beneficial for the previously normoxic-trained group. Repeated sprint (8 × 20 m) and Yo-Yo Intermittent Recovery Level 1 (YYIR1) performances were tested twice at baseline (Pre 1 and Pre 2) and weekly after (Post 1-3) the initial intervention (intervention 1) and again weekly after the second "top-up" intervention (Post 4-5). After each training set, heart rate, oxygen saturation, and rate of perceived exertion were recorded. Compared to baseline (mean of Pre 1 and Pre 2), both the hypoxic and normoxic groups similarly lowered fatigue over the 8 sprints 1 week after the intervention (Post 1: -1.8 ± 1.6%, -1.5 ± 1.4%, mean change ± 90% CI in HYP and NORM groups, respectively). However, from Post 2 onwards, only the hypoxic group maintained the performance improvement compared to baseline (Post 2: -2.1 ± 1.8%, Post 3: -2.3 ± 1.7%, Post 4: -1.9 ± 1.8%, and Post 5: -1.2 ± 1.7%). Compared to the normoxic group, the hypoxic group was likely to have substantially less fatigue at Post 3-5 (-2.0 ± 2.4%, -2.2 ± 2.4%, -1.6 ± 2.4% Post 3, Post 4, Post 5, respectively). YYIR1 performances improved throughout the recovery period in both groups (13-37% compared to baseline) with unclear differences found between groups. The addition of two sessions of "top-up" training after intervention 1, had little effect on either group. Repeat-sprint training in hypoxia for six sessions increases repeat sprint ability but not YYIR1 performance in well-trained rugby players

Bone Marrow–on–a–Chip Replicates Hematopoietic Niche Physiology in Vitro

Current in vitro hematopoiesis models fail to demonstrate the cellular diversity and complex functions of living bone marrow; hence, most translational studies relevant to the hematologic system are conducted in live animals. Here we describe a method for fabricating 'bone marrow–on–a–chip' that permits culture of living marrow with a functional hematopoietic niche in vitro by first engineering new bone in vivo, removing it whole and perfusing it with culture medium in a microfluidic device. The engineered bone marrow (eBM) retains hematopoietic stem and progenitor cells in normal in vivo–like proportions for at least 1 week in culture. eBM models organ-level marrow toxicity responses and protective effects of radiation countermeasure drugs, whereas conventional bone marrow culture methods do not. This biomimetic microdevice offers a new approach for analysis of drug responses and toxicities in bone marrow as well as for study of hematopoiesis and hematologic diseases in vitro.Engineering and Applied Science

Microchannel neural interface manufacture by stacking silicone and metal foil laminae

Objective: Microchannel neural interfaces (MNIs) overcome problems with recording from peripheral nerves by amplifying signals independent of Node of Ranvier position. Selective recording and stimulation using an MNI requires good insulation between microchannels and a high electrode density. We propose that stacking microchannel laminae will improve selectivity over single layer MNI designs due to the increase in electrode number and an improvement in microchannel sealing. Approach: This paper describes a manufacturing method for creating MNIs which overcomes limitations on electrode connectivity and microchannel sealing. Laser cut silicone – metal foil laminae were stacked using plasma bonding to create an array of microchannels containing tripolar electrodes. Electrodes were DC etched and electrode impedance and cyclic voltammetry were tested. Main results: MNIs with 100 µm and 200 µm diameter microchannels were manufactured. High electrode density MNIs are achievable with electrodes present in every microchannel. Electrode impedances of 27.2 ± 19.8 kΩ at 1kHz were achieved. Following 2 months of implantation in Lewis rat sciatic nerve, micro-fascicles were observed regenerating through the MNI microchannels. Significance: Selective microchannel neural interfaces with the peripheral nervous system may allow upper limb amputees to control prostheses intuitively

Sustainable Living Teen Volunteers

Maine 4-H Youth Development programs have produced nationally-recognized environmental education and healthy lifestyle curricula that are research-based and have reached thousands of participants. Our new statewide initiative in Sustainable Living Education for youth and adults provides an excellent context for the CYFAR Maine Sustainable Communities Project (MSCP), Sustainable Living Teen Volunteers (SLTV). The SLTV program will be conducted at two of our current 4-H Camp and Learning Centers in collaboration with local schools. After completing their training, teens will teach sustainable living concepts and practices to youth in middle schools and 4-H clubs. The SLTVs will learn valuable life skills and participate in service learning in their communities. Richard Louv (2005) has documented some disturbing trends in current society: children ages six to eighteen are spending 30 hours or more per week using electronic media; 30% of children and teens are dangerously overweight or obese; nearly eight million children in the US have been diagnosed with learning disabilities and mental disorders; a 600 percent increase in prescriptions of psychotropic drugs in the last decade; among others. These trends have been linked to the decline in physical, imaginative, unstructured, outdoor play that was an everyday occurrence just a generation ago. In addition, evidence suggests that many of our youth do not value the environment, conservation, living sustainably, or outdoor experiences. Our Sustainable Living Teen Volunteer model will play a significant role in changing these attitudes and making a difference in the lives of Maine youth and their communities. It is expected that, over the course of the five years of this program, high school and middle school-aged youth will gain knowledge and learn skills related to living more sustainable lifestyles, and will share the knowledge and skills with other students, with their families, and with community members. It is expected that practices and behaviors that contribute to living a more sustainable lifestyle will be adopted by participants and those they teach, leading to improved quality of life and quality of the environment

Understanding young people's transitions in university halls through space and time

This article contributes to the theoretical discussion about young people's transitions through space and time. Space and time are complex overarching concepts that have creative potential in deepening understanding of transition. The focus of this research is young people's experiences of communal living in university halls. It is argued that particular space-time concepts draw attention to different facets of experience and in combination deepen the understanding of young people's individual and collective transitions. The focus of the article is the uses of the space-time concepts 'routine', 'representation', 'rhythm' and 'ritual' to research young people's experiences. The article draws on research findings from two studies in the North of England. © 2010 SAGE Publications

Preventing obesity in infants: the growing healthy feasibility trial protocol

INTRODUCTION: Early childhood is an important period for establishing behaviours that will affect weight gain and health across the life course. Early feeding choices, including breast and/or formula, timing of introduction of solids, physical activity and electronic media use among infants and young children are considered likely determinants of childhood obesity. Parents play a primary role in shaping these behaviours through parental modelling, feeding styles, and the food and physical activity environments provided. Children from low socio-economic backgrounds have higher rates of obesity, making early intervention particularly important. However, such families are often more difficult to reach and may be less likely to participate in traditional programs that support healthy behaviours. Parents across all socio-demographic groups frequently access primary health care (PHC) services, including nurses in community health services and general medical practices, providing unparalleled opportunity for engagement to influence family behaviours. One emerging and promising area that might maximise engagement at a low cost is the provision of support for healthy parenting through electronic media such as the Internet or smart phones. The Growing healthy study explores the feasibility of delivering such support via primary health care services. METHODS: This paper describes the Growing healthy study, a non-randomised quasi experimental study examining the feasibility of an intervention delivered via a smartphone app (or website) for parents living in socioeconomically disadvantaged areas, for promoting infant feeding and parenting behaviours that promote healthy rather than excessive weight gain. Participants will be recruited via their primary health care practitioner and followed until their infant is 9 months old. Data will be collected via web-based questionnaires and the data collected inherently by the app itself. ETHICS AND DISSEMINATION: This study received approval from the University of Technology Sydney Ethics committee and will be disseminated via peer-reviewed publications and conference presentations

Can fitness tests be used to predict the vascular health of physically active older adults?

Objective There is an increased risk of cardiovascular diseases among older adults. This research aimed to determine which fitness tests could predict the vascular health of older adults using the gold standard pulse wave velocity (PWV) (applanation tonometry). Methods This cross-sectional study analysed 81 physically active adults (n=57 females) aged 64-91 (M=78±6.42) residing in independent living communities. A four-component fitness test included the 4-stage balance test (balance and falling assessment), six-minute walk test (SMWT) (aerobic exercise capacity), 30-second sit-to-stand test (postural hypotension and falling assessment), and the grip strength test (upper body strength) along with a PWV measurement. A regression use the four fitness tests as predictors of PWV for all participants. Pearson correlations then analysed these variables by subgroups of sex and age. Results When including all 81 participants, the four component fitness test significantly accounted for 20% of the variance in PWV (R2=.20; F(4,76)=4.70, p=.002) among older adults. Of the four components, higher sit-to-stand scores correlated with having healthy arteries (β=-.27, p=.027), but higher grip strength scores correlated with having unhealthy arteries (β=.23, p=.036). Neither the SMWT nor the balance test significantly contributed to the regression model. Pearson correlations indicated for men that better balance correlated significantly with healthy arteries (r=-.47, p=.011). For women, higher sit-to-stand scores (r=-.43, p ≤.001) and better balance (r=-.23, p=.045) correlated significantly with healthy arteries. Among 70-79 year olds, higher sit-to-stand scores (r=-.41, p =.002) and better balance (r=-.32, p=.014) correlated significantly with healthy arteries. Among 80-89 year olds, higher SMWT (r=-.40, p =.024) correlated significantly with healthy arteries. Conclusions The four-component fitness test did significantly predict arterial stiffness in older adults, but grip strength scores were unexpectedly negatively related to healthy arteries whereas sit-to-stand was positively related. In most groups, better balance and higher sit-to-stand scores were correlated to healthy arteries which was somewhat surprising. Finally, older participants were the only subgroup which showed a correlation between healthier arteries and higher SMWT scores. Given the SMWT is an aerobic exercise capacity assessment, it is surprising it did not correlate stronger to PWV

Investigating the relationships between lifestyle physical activity and diet on vascular health among older adults

Purpose This research aimed to investigate how behaviours of lifestyle physical activity (PA) and diet predict and correlate with vascular health in older adults using the gold standard measure of pulse wave velocity (PWV). Methods This cross-sectional study analysed 83 adults aged 64-91 years (M=78±6.44) residing in independent living communities. Dietary questions were taken from the Harvard disease risk tool. The Yale physical activity survey allowed the calculation of metabolic equivalents of task (METmins). PWV was collected using a non-invasive device (applanation tonometry). A hierarchical regression was calculated whereby covariates of taking blood pressure medication (BPM) and age (both known to affect PWV) were controlled in model 1 and diet and METmins were added into model 2. Pearson correlations were then calculated to determine individual correlations with PWV by subgroups of sex and age. Results The model 1 regression (R²=.29; F(2,79)=16.00, p<.001) indicated that covariates of BPM and age accounted for 29% (p≤.000) of the variance in PWV, but when diet and METmins were added in model 2 (R²=.31; F(4,77)=8.56, p<.001) they only contributed 2% more (non-significant change, p=.35) to the prediction of PWV. Healthier arteries in males correlated significantly with higher METmins (r=-.54, p=.004) and younger participants (r=.40, p=.027). Healthier arteries in females correlated significantly with younger participants (r=.49, p=.000), no BPM (r=.36, p=.002), and higher METmins (r=-.25, p=.029). Among 64-78 year olds, healthier arteries were correlated with no BPM (r=.35, p=.011), and healthier diets (r=-.26, p=.046), but not with METmins. Alternatively, 79-91 year-olds showed healthier arteries correlated with higher METmins (r=-.36, p=.012), but not with diet. Conclusions After controlling for age and BPM (model 1) in the regression, diet and METmins (model 2) were unable to significantly contribute to the prediction of arterial stiffness in older adults. Both males and females showed correlations between healthier arteries and higher METmins, but not between arterial health and diet, suggesting LPA is more correlated to arterial health than diet. Those aged 64-78 had healthy arteries in correlation with a healthy diet, whereas 79-91 year olds had healthy arteries in correlation with higher METmins

A broad distribution of the alternative oxidase in microsporidian parasites

Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of ironsulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX), a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1) as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosome