A Description of Variability of Pacing in Marathon Distance Running

The purpose of this study was twofold: 1) to describe variability of pacing during a marathon and 2) to determine if there is a relationship between variability of pacing and marathon performance. Publically available personal global positioning system profiles from two marathons (Race 1 n = 116, Race 2 n = 169) were downloaded (http://connect.garmin.com) for analysis. The coefficient of variation of velocity (Velcov) was calculated for each profile. Each profile was categorized as finishing in under 3.9 hours, between 3.9 and 4.6 hours, or longer than 4.6 hours. Linear and quadratic lines of best fit were computed to describe the relationship between marathon finish time and Velcov. A 2 (Race) x 3 (bin) analysis of variance (ANOVA) was used to compare the dependent variable (Velcov) between races and the marathon bin finish times. Velcov was not influenced by the interaction of finish time bin and Race (p\u3e0.05) and was not different between races (Race 1: 16.6 ± 6.4%, Race 2: 16.8 ± 6.6%, p\u3e0.05). Velcov was different between finish time categories (p\u3c0.05) for each race such that Velcov was lower for faster finish times. Using combined data from both races, linear (marathon finish time = marathon finish time = 0.09Velcov + 2.9, R^2 = 0.46) and quadratic (marathon finish time = -0.0006 Velcov 2 + 0.11 Velcov + 2.7, R^2 = 0.46) lines of best fit were significant (p\u3c0.05). Slower marathon finishers had greater variability of pace compared to faster marathoner finishers

Is the relationship between stride length, frequency, and velocity influenced by running on a treadmill or overground?

International Journal of Exercise Science 10(7): 1067-1075, 2017. The purpose of the study was to compare the relationship between stride length (SL), stride frequency (SF), and velocity while running on a treadmill and overground. Participants (n=10; 22.3±2.6 yrs; 1.71±.08 m; 71.4±15.5 kg) completed a total of 14 runs (7 treadmill, 7 overground) with each run at a different velocity. SL, SF, and velocity data were recorded using wearable technology (Garmin, Fenix2). The outdoor trials occurred first. The treadmill velocities were selected to match the range of velocities used overgroud. SL vs. velocity plots were generated for treadmill and overground data for each participant and fit with a 2nd order polynomial in the form of SL=Av2+Bv+C. Each equation coefficient (i.e., A, B, C) was averaged across participants and compared between treadmill and overground using paired t-tests. The A coefficient (v2 term) was different treadmill vs. overground (p=0.031). Neither B (p=0.136) nor C (p=0.260) coefficients were different treadmill vs. overground. It was concluded that the A coefficient (v2 term) for SL vs. velocity was larger during overground vs. treadmill running. This is an indication that the strategy of changing SL across velocities was different when on the treadmill vs. overground. Specifically, while running on a treadmill, SL continued to increase in a more linear manner than when running overground

Sport And Mental Health Performance Optimization in An Adolescent Gymnast: A Case Evaluation

The Optimum Performance Program in Sports (TOPPS) is a multi-component, sport-specific Family Behavior Therapy that has demonstrated improved sport performance, relationships, and mental health outcomes in adult and adolescent athletes with, and without, diagnosed mental health disorders in clinical trials. The current case trial demonstrates successful implementation of a novel component of TOPPS (i.e., talk aloud optimal sport performance imagery leading to dream mapping) in a biracial Latina and White adolescent gymnast without a mental health diagnosis. The participant demonstrated significant improvements from baseline to both post-treatment and 3-month follow-up in severity of mental health functioning, factors interfering with sports performance, and her relationships with teammates, coaches, and family. Results suggest it may be possible to optimize mental health through sport performance optimization

Slip-Sliding Away: Serial Changes and Homoplasy in Repeat Number in the Drosophila yakuba Homolog of Human Cancer Susceptibility Gene BRCA2

Several recent studies have examined the function and evolution of a Drosophila homolog to the human breast cancer susceptibility gene BRCA2, named dmbrca2. We previously identified what appeared to be a recent expansion in the RAD51-binding BRC-repeat array in the ancestor of Drosophila yakuba. In this study, we examine patterns of variation and evolution of the dmbrca2 BRC-repeat array within D. yakuba and its close relatives. We develop a model of how unequal crossing over may have produced the expanded form, but we also observe short repeat forms, typical of other species in the D. melanogaster group, segregating within D. yakuba and D. santomea. These short forms do not appear to be identical-by-descent, suggesting that the history of dmbrca2 in the D. melanogaster subgroup has involved repeat unit contractions resulting in homoplasious forms. We conclude that the evolutionary history of dmbrca2 in D. yakuba and perhaps in other Drosophila species may be more complicated than can be inferred from examination of the published single genome sequences per species

Health and survival of young children in southern Tanzania

With a view to developing health systems strategies to improve reach to high-risk groups, we present information on health and survival from household and health facility perspectives in five districts of southern Tanzania. We documented availability of health workers, vaccines, drugs, supplies and services essential for child health through a survey of all health facilities in the area. We did a representative cluster sample survey of 21,600 households using a modular questionnaire including household assets, birth histories, and antenatal care in currently pregnant women. In a subsample of households we asked about health of all children under two years, including breastfeeding, mosquito net use, vaccination, vitamin A, and care-seeking for recent illness, and measured haemoglobin and malaria parasitaemia. In the health facility survey, a prescriber or nurse was present on the day of the survey in about 40% of 114 dispensaries. Less than half of health facilities had all seven 'essential oral treatments', and water was available in only 22%. In the household survey, antenatal attendance (88%) and DPT-HepB3 vaccine coverage in children (81%) were high. Neonatal and infant mortality were 43.2 and 76.4 per 1000 live births respectively. Infant mortality was 40% higher for teenage mothers than older women (RR 1.4, 95% confidence interval (CI) 1.1 - 1.7), and 20% higher for mothers with no formal education than those who had been to school (RR 1.2, CI 1.0 - 1.4). The benefits of education on survival were apparently restricted to post-neonatal infants. There was no evidence of inequality in infant mortality by socio-economic status. Vaccine coverage, net use, anaemia and parasitaemia were inequitable: the least poor had a consistent advantage over children from the poorest families. Infant mortality was higher in families living over 5 km from their nearest health facility compared to those living closer (RR 1.25, CI 1.0 - 1.5): 75% of households live within this distance. Relatively short distances to health facilities, high antenatal and vaccine coverage show that peripheral health facilities have huge potential to make a difference to health and survival at household level in rural Tanzania, even with current human resources

The Genetic Signatures of Noncoding RNAs

The majority of the genome in animals and plants is transcribed in a developmentally regulated manner to produce large numbers of non–protein-coding RNAs (ncRNAs), whose incidence increases with developmental complexity. There is growing evidence that these transcripts are functional, particularly in the regulation of epigenetic processes, leading to the suggestion that they compose a hitherto hidden layer of genomic programming in humans and other complex organisms. However, to date, very few have been identified in genetic screens. Here I show that this is explicable by an historic emphasis, both phenotypically and technically, on mutations in protein-coding sequences, and by presumptions about the nature of regulatory mutations. Most variations in regulatory sequences produce relatively subtle phenotypic changes, in contrast to mutations in protein-coding sequences that frequently cause catastrophic component failure. Until recently, most mapping projects have focused on protein-coding sequences, and the limited number of identified regulatory mutations have been interpreted as affecting conventional cis-acting promoter and enhancer elements, although these regions are often themselves transcribed. Moreover, ncRNA-directed regulatory circuits underpin most, if not all, complex genetic phenomena in eukaryotes, including RNA interference-related processes such as transcriptional and post-transcriptional gene silencing, position effect variegation, hybrid dysgenesis, chromosome dosage compensation, parental imprinting and allelic exclusion, paramutation, and possibly transvection and transinduction. The next frontier is the identification and functional characterization of the myriad sequence variations that influence quantitative traits, disease susceptibility, and other complex characteristics, which are being shown by genome-wide association studies to lie mostly in noncoding, presumably regulatory, regions. There is every possibility that many of these variations will alter the interactions between regulatory RNAs and their targets, a prospect that should be borne in mind in future functional analyses

Investigation of Swimming Economy while Wearing Different Triathlon Wetsuit Styles at Submaximal Front Crawl Swimming

Triathlon wetsuits commonly use for the potential benefits of swimming performance and thermoregulation. Triathletes may select different wetsuit styles depending on many factors (e.g., temperature regulation swimming technique, body type, and training purpose). However, there is a lack of empirical evidence of how different wetsuit styles affect the physiological responses to swimming. PURPOSE: The purpose of this study was to investigate the physiological responses during submaximal intensity front crawl swimming using different wetsuit styles. METHODS: Fourteen participants (n=6 men, n=8 women; all recreational triathletes or swimmers) completed a swimming graded exercise test wearing a swimsuit only to determine maximal oxygen consumption (VO2max). A test speed was calculated from these data to represent 80% VO2max. Participants then completed four 4-min submaximal swimming conditions at this speed: regular swimsuit (NWS), buoyancy short (BS), sleeveless (SLW), and full sleeve wetsuit (FSW). The order of the conditions was randomized. All conditions were conducted in a swimming flume and metabolic measurements were made using a metabolic cart with a mixing chamber. The rate of O2 consumption (VO2), rate of CO2 production (VCO2), ventilation (VE), heart rate (HR), and respiratory exchange ratio (RER) were determined as the average for the last minute of each condition. Rating of perceived exertion (RPE) was assessed after each condition. RESULTS: VO2 and HR were statistically different by wetsuit conditions (p \u3c 0.01; NWS: 37.5±5.9 ml·kg-1min-1,148±12 bpm, BS: 34.0±6.4 ml·kg-1min-1,142±14 bpm, SLW: 31.4±4.9 ml·kg-1min-1, 137±12 bpm, and FSW: 32.2±5.3 ml·kg-1min-1,139±12 bpm). In addition, VCO2, VE, RER, and RPE were significantly influenced by wetsuit conditions (VCO2 and VE: p \u3c 0.01, RER and RPE: p \u3c 0.05). Swimming without a wetsuit significantly increased VO2, HR, VCO2, and VE relative to the other conditions (p \u3c 0.05). Furthermore, all dependent variables were not statistically different between SLW and FSW (p \u3e 0.05). CONCLUSION: Swimming with a regular swimsuit is the least economical at the test speed. Additionally, it seems that either SLW or FSW can be used without significant physiological changes when swimming at the intensity of the triathlon race

Chromosomal variation of the common shrew Sorex araneus L. in Britain

Throughout the range of the common shrew (Sorex araneus Linnaeus 1767), repeated Robertsonian fusion mutations have led to a karyotypic polymorphism dividing the species into chromosome races. Studies of fertility were undertaken in the male, both of homozygotes and of heterozygotes forming meiotic multivalents of varying complexity. Observations made at pachytene, diakinesis/metaphase I and metaphase II did not provide evidence for fertility impairment in homozygotes or simple heterozygotes. Males forming a chain of seven chromosomes during meiotic prophase I were produced through a program of captive breeding, and were brought to premature sexual maturity through photoperiod manipulation. In these more complex heterozygotes, incomplete pachytene pairing was frequently observed (68% of cells), germ cell death was found to be elevated (23%), and data from analysis of metaphase II spreads are indicative of an increase in nondisjunction above background of approximately 10%. At the interface between two chromosome races, a complex of clines of chromosome frequency can be found. Field studies determined the routes and widths of four such clines (ko, 8.6km; kg, 28.4km; no, 37.1km; pr, 47.9km), and concluded that the courses taken are entirely consistent with maintenance through a mechanism of heterozygote disadvantage. Estimates of disadvantage made from cline width were in close agreement with those derived from the fertility studies.</P