Design of a Guarded Hot Plate for Measuring Thin Specimens of Polymer and Composite Materials

The National Physical Laboratory (NPL) has developed a new design of guarded hot plate apparatus specifically for absolute measurements on thin specimens of medium thermal conductivity materials, such as the polymer composites that are becoming more widely used in aerospace and other advanced manufacturing sectors. Although NPL has an existing measurement facility based on a commercially manufactured apparatus conforming to ASTM E1530, this current facility is not based on an absolute measurement technique and is not able to provide the low measurement uncertainty or flexibility that is increasingly being demanded by industrial users of this NPL service. The target specification for this new NPL guarded hot plate is the measurement of materials with thermal conductivity in the range 0.1–10 W·m−1·K−1 using specimens with thickness of 1–20 mm and over the temperature range −100°C to 250°C. This is achieved using a new design of guarded heater plate and a temperature-controlled environmental chamber. This chamber can be evacuated and specific gases can be introduced, enabling measurements on porous materials under a wide range of environments. It can be used in either a single specimen or a double specimen configuration, and with specimen diameters of either 75 mm or 50.8 mm that is used in many older styles of comparative measurement apparatus. During the commissioning of this new measurements facility, it is planned to investigate various approaches for reducing thermal contact resistance between the specimen and plates. This facility will then provide the flexibility for meeting a wider range of requirements from industrial customers

Evidence of validity of the Fear of COVID-19 Scale (FCV-19S) in the Argentinian context.

The Fear of COVID-19 Scale (FCV-19S) is one of the most widely psychometric instruments used for assessing the fear of COVID-19 in the international context. The present study aims to analyze the evidence of validity based on the internal structure, in relation to other variables and reliability of the FCV-19S among a sample of 223 adults from Argentina aged between 21 and 85 years (M = 50.96 years; SD = 16.57) and of both sexes (males = 30.5%; females = 69.5%). Results indicated very good values in terms of its reliability (ω = .94; α = .93). The confirmatory factor analysis yields adequate values in terms of the validity criteria based on the internal structure of the scale, providing empirical support for a unidimensional model. Likewise, the associations between the FCV-19S and the Brief Fear of Death Scale provide evidence of validity related to other variables. The study demonstrates that the FCV-19S is a valid and reliable instrument to interpret the fear of COVID-19 in the local context, although future studies should continue to investigate its psychometric properties. La Escala de Miedo al COVID-19 (FCV-19S)constituye uno de los instrumentos psicométricos másempleados para la evaluación del miedo al COVID-19 en elcontexto internacional. El presente estudio se propone analizarlas evidencias de validez basada en la estructura interna, enla relación con otras variables y fiabilidad de la FCV-19S enuna muestra de 223 adultos de Argentina con edades entre21 y 85 años (M = 50.96 años; DE = 16.57) y de ambossexos (Hombres = 30,5%; Mujeres = 69,5%). La FCV-19Spresenta valores aceptables de confiabilidad (ω = .94; α = .93).El análisis factorial confirmatorio arroja valores adecuados encuanto a los criterios de validez basada en la estructura internade la escala, aportando apoyo empírico en favor de un modelounidimensional. Asimismo, las asociaciones entre la FCV-19Sy la Escala de Miedo a la Muerte Abreviada aportan evidenciasde validez en relación con otras variables. El estudio demuestraque la FCV-19S es un instrumento válido y confiable parainterpretar el miedo al COVID-19 en el contexto local, aunquefuturos estudios deberían continuar indagando sus propiedadespsicométricas

The prevalence and frequency of menstrual cycle symptoms are associated with women’s availability to train and compete: A study of 6,812 exercising women recruited using the STRAVA™ exercise app

Objectives: The menstrual cycle can affect sports participation and exercise performance. There are very few data on the specific menstrual cycle symptoms (symptoms during various phases of the cycle, not only during menstruation) experienced by exercising women. We aimed to characterise the most common symptoms; the number and frequency of symptoms; and we evaluated whether menstrual cycle symptoms were associated with sporting outcomes. Methods: 6,812 adult women of reproductive age (mean age: 38.3 (8.7) years) who were not using combined hormonal contraception were recruited via the STRAVA exercise app user database and completed a 39-part survey. Respondents were from seven geographical areas, and questions were translated and localised to each region (Brazil, n=1,288; France, n=1,911; Germany, n=1,178; Spain, n=1,204; UK & Ireland, n=2,311; and USA, n=2,479). The survey captured exercise behaviours; current menstrual status; the presence and frequency of menstrual cycle symptoms; medication use for symptoms; perceived effects of the menstrual cycle on exercise and work behaviours; and history of hormonal contraception use. We propose a novel Menstrual Symptom index (MSi) based on the presence and frequency of 18 commonly reported symptoms (range 0-54 where 54 would be all 18 symptoms each occurring very frequently). Results: The most prevalent menstrual cycle symptoms were mood changes/anxiety (90.6%), tiredness/fatigue (86.2%), stomach cramps (84.2%), and breast pain/tenderness (83.1%). After controlling for BMI, training volume and age, the Menstrual Symptom Index was associated with a greater likelihood of missing or changing training (OR= 1.09 (CI: 1.08,1.10); p<0.05), missing a sporting event/competition (OR= 1.07 (CI: 1.06,1.08); p=<0.05), absenteeism from work/academia (OR= 1.08 (CI: 1.07,1.09); p=<0.05), and use of pain medication (OR= 1.09 (CI: 1.08,1.09); p=<0.05). Conclusion: Menstrual cycle symptoms are very common in exercising women and women report that these symptoms compromise their exercise participation and work capacity. The Menstrual Symptom Index needs to be formally validated (psychometrics); at present it provides an easy way to quantify the frequency of menstrual cycle symptoms

Increased Oxidative Stress in Injured and Ill Elite International Olympic Rowers

Identifying strategies that reduce the risk of illness and injury is an objective of sports science and medicine teams. No studies have examined the relationship between oxidative stress (OS) and illness or injury in international athletes undergoing periods of intensified training and competition. Purpose: We aimed to identify relationships between illness, injury and OS. Methods: A longitudinal, observational study of elite male rowers (n=10) was conducted over 18-weeks leading into World Championships. Following a recovery day and a 12-hour fast, hydroperoxides (FORT) and total anti-oxidant capacity (FORD) were measured in venous blood, with the ratio calculated as the oxidative stress index (OSI). At all study time points, athletes were independently dichotomized as ill or not ill, injured or not injured. OS data were compared between groups using independent t-tests. A Cox proportional hazard model was used to assess the association of OS with injury and illness while adjusting for age and body mass index. Results: FORD was lower (p<0.02) and OSI was higher (p<0.001) with illness than without illness. FORT and OSI were higher with injury than without injury (p<0.001). FORD exerts a protective effect on illness with 0.5 mmol•L-1 increase related to a 30.6% illness risk reduction (p=0.014), and OSI exerts a harmful effect on illness risk with a 0.5 unit increase in OSI related to an 11.3% increased risk (p=0.036). Conclusion: OS is increased in injured and ill athletes. Monitoring OS may be advantageous in assessing recovery from, and in reducing injury and illness risk given the association

Sensitive periods for the effect of childhood adversity on DNA methylation: Results from a prospective, longitudinal study

Background: Exposure to "early life" adversity is known to predict DNA methylation (DNAm) patterns that may be related to psychiatric risk. However, few studies have investigated whether adversity has time-dependent effects based on the age at exposure.Methods: Using a two-stage structured life course modeling approach (SLCMA), we tested the hypothesis that there are sensitive periods when adversity induced greater DNAm changes. We tested this hypothesis in relation to two alternatives: an accumulation hypothesis, in which the effect of adversity increases with the number of occasions exposed, regardless of timing, and a recency model, in which the effect of adversity is stronger for more proximal events. Data came from the Accessible Resource for Integrated Epigenomics Studies (ARIES), a subsample of mother-child pairs from the Avon Longitudinal Study of Parents and Children (ALSPAC; n=691-774).Results: After covariate adjustment and multiple testing correction, we identified 38 CpG sites that were differentially methylated at age 7 following exposure to adversity. Most loci (n=35) were predicted by the timing of adversity, namely exposures before age 3. Neither theaccumulation nor recency of the adversity explained considerable variability in DNAm. A standard EWAS of lifetime exposure (vs. no exposure) failed to detect these associations.Conclusions: The developmental timing of adversity explains more variability in DNAm than the accumulation or recency of exposure. Very early childhood appears to be a sensitive period when exposure to adversity predicts differential DNAm patterns. Classification of individuals as exposed vs. unexposed to “early life” adversity may dilute observed effects

Groundwater Remediation at the 100-HR-3 Operable Unit Hanford Site Washington USA - 11507

The 100-HR-3 Groundwater Operable Unit (OU) at the Hanford Site underlies three former plutonium production reactors and the associated infrastructure at the 100-D and 100-H Areas. The primary contaminant of concern at the site is hexavalent chromium; the secondary contaminants are strontium-90, technetium-99, tritium, uranium, and nitrate. The hexavalent chromium plume is the largest plume of its type in the state of Washington, covering an area of approximately 7 km{sup 2} (2.7 mi{sup 2}) with concentrations greater than 20 {micro}g/L. Concentrations range from 60,000 {micro}g/L near the former dichromate transfer station in the 100-D Area to large areas of 20 to 100 {micro}g/L across much of the plume area. Pump-and-treat operations began in 1997 and continued into 2010 at a limited scale of approximately 200 gal/min. Remediation of groundwater has been fairly successful in reaching remedial action objectives (RAOs) of 20 {micro}g/L over a limited region at the 100-H, but less effective at 100-D. In 2000, an in situ, permeable reactive barrier was installed downgradient of the hotspot in 100-D as a second remedy. The RAOs are still being exceeded over a large portion of the area. The CH2M HILL Plateau Remediation Company was awarded the remediation contract for groundwater in 2008 and initiated a remedial process optimization study consisting of modeling and technical studies intended to enhance the remediation. As a result of the study, 1,400 gal/min of expanded treatment capacity are being implemented. These new systems are designed to meet 2012 and 2020 target milestones for protection of the Columbia River and cleanup of the groundwater plumes

Objective measures of strain and subjective muscle soreness differ between positional groups and season phases in American collegiate football.

Purpose: To assess objective strain and subjective muscle soreness in ‘Bigs’ (Offensive and Defensive Line), ‘Combos’ (Tight Ends, Quarterbacks, Line and Running-Backs) and ‘Skills’ (Wide Receivers and Defensive Backs) American College Football (ACF) players during off-season, fall-camp and in-season phases. Methods: Twenty-three male players were assessed once weekly (3-week off-season, 4-week fall-camp, 3-week in-season) for hydroperoxides (FORT), antioxidant capacity (FORD) and oxidative stress index (OSI)), countermovement jump flight-time, reactive strength index modified (RSImod), and subjective soreness. Linear mixed-models analysed the effect of a two within-subject standard deviation change between predictor and dependent variables. Results: Compared to fall-camp and in-season phases, off-season FORT (P=<.001 and <.001), FORD (P=<.001 and <.001), OSI (P=<.001 and <.001), Flight-time (P=<.001 and <.001), RSImod (P=<.001 and <.001) and soreness (P=<.001 and <.001) were higher for ‘Bigs’, whilst FORT (P=<.001 and <.001) and OSI (P=.02 and <.001) were lower for ‘Combos’. FORT was higher for ‘Bigs’ compared to ‘Combos’ in all phases (P=<.001, .02 and .01). FORD was higher for ‘Skills’ compared to ‘Bigs’ in off-season (P=.02) and ‘Combos’ in-season (P=.01). OSI was higher for ‘Bigs’ compared to ‘Combos’ (P=<.001) and ‘Skills’ (P=.01) during off-season and to ‘Combos’ in-season (P=<.001). Flight-time was higher for ‘Skills’ in fall-camp compared to ‘Bigs’ (P=.04) and to ‘Combos’ in-season (P=.01). RSImod was higher for ‘Skills’ during off-season compared to ‘Bigs’ (P=.02) and ‘Combos’ during fall-camp (P=.03), and in-season (P=.03). Conclusion: Off-season ACF training resulted in higher objective strain and subjective muscle soreness in ‘Bigs’ compared to fall-camp and during in-season compared to ‘Combos’ and ‘Skills’ players

Modelling height in adolescence: a comparison of methods for estimating the age at peak height velocity

Background: Controlling for maturational status and timing is crucial in lifecourse epidemiology. One popular non-invasive measure of maturity is the age at peak height velocity (PHV). There are several ways to estimate age at PHV, but it is unclear which of these to use in practice. Aim: To find the optimal approach for estimating age at PHV. Subjects and methods: Methods included the Preece & Baines non-linear growth model, multi-level models with fractional polynomials, SuperImposition by Translation And Rotation (SITAR) and functional data analysis. These were compared through a simulation study and using data from a large cohort of adolescent boys from the Christ’s Hospital School. Results: The SITAR model gave close to unbiased estimates of age at PHV, but convergence issues arose when measurement error was large. Preece & Baines achieved close to unbiased estimates, but shares similarity with the data generation model for our simulation study and was also computationally inefficient, taking 24 hours to fit the data from Christ’s Hospital School. Functional data analysis consistently converged, but had higher mean bias than SITAR. Almost all methods demonstrated strong correlations (r > 0.9) between true and estimated age at PHV. Conclusions: Both SITAR or the PBGM are useful models for adolescent growth and provide unbiased estimates of age at peak height velocity. Care should be taken as substantial bias and variance can occur with large measurement error