Sweat lactate response during cycling at 30 degrees C and 18 degrees C WBGT

Sweat lactate reflects eccrine gland metabolism. However, the metabolic tendencies of eccrine glands in a hot versus thermoneutral environment are not well understood. Sixteen male volunteers completed a maximal cycling trial and two 60-min cycling trials [30 degrees C = 30 +/- 1 degrees C and 18 degrees C = 18 +/- 1 degrees C wet bulb globe temperature (WBGT)]. The participants were requested to maintain a cadence of 60 rev min(-1) with the intensity individualized at approximately 90% of the ventilatory threshold. Sweat samples at 10, 20, 30, 40, 50 and 60 min were analysed for lactate concentration. Sweat rate at 30 degrees C (1380 +/- 325 ml x h(-1)) was significantly greater (P < 0.05) than at 18 degrees C (632 +/- 311 ml x h(-1)). Sweat lactate concentration was significantly greater (P < 0.05) at each time point during the 18 degrees C trial, with values between trials tending to converge across time. During the 30 degrees C trial, both heart rate (20, 30, 40, 50 and 60 min) and rectal temperature (30, 40, 50 and 60 min) were significantly higher than in the 18 degrees C trial. Higher sweat lactate concentrations coupled with lower sweat rates may indicate a greater relative contribution of oxygen-independent metabolism within eccrine glands during exercise at 18 degrees C. Decreases in sweat lactate concentration across time suggest either greater dilution due to greater sweat volume or increased reliance on aerobic metabolism within eccrine glands. The convergence of lactate concentrations between trials may indicate that time-dependent modifications in sweat gland metabolism occur at different rates contingent partially on environmental conditions.     

Collection development for new librarians: Advice from the trenches

There are many challenges facing new librarians in the academic environment, including collection development. This article analyzes the topic of collection development and how it relates to new professionals in the field of librarianship. The article contains a literature review of papers discussing the collection development curriculum in library and information science programs, expected skills required of collection development offices, and library training programs for new librarians. The article also provides practical advise by recent graduates and their collection development experiences. Topics of discussion include acclimation to a new environment, collection development policies and procedures, liaison work, resource selection, and time management.     

Use of the decomposition technique to test the educational screening hypothesis

The principal issue addressed in this article is whether or not education directly creates productivity and earnings as taught by traditional human capital theory. If not, an alternative argument could be that employers use education as a screening device to select employees. Employing the decomposition technique to compare income for self-employed and private sector employees, evidence is presented which rejects the screenist theory.     

Perceived Local Job Prospects and School Connectedness in a Struggling Rural Economy: A Life-Course Perspective

Late in first decade of the 2000s, the closing of pulp and paper mills in the rural northeastern United States contributed to economic decline in the region and to rising concerns about population decline due to out-migration among local emerging adults in search of occupational or educational opportunities. In this context, and drawing on a life-course framework, the present study used four waves of panel data from the population of 7th- and 11th-grade public school students in a rural northeastern U.S. county to explore whether the county unemployment rate was related to perceived local job prospects; school connectedness was related to subsequent perceived job prospects; and the effects of county unemployment and school connectedness on perceived local job prospects varied by age cohort. Initially, changes in respondents’ perceptions about local job prospects paralleled shifts in local unemployment similarly for both cohorts; yet after the older cohort respondents had completed high school, their perceived local job prospects fell sharply, while perceptions among the younger cohort respondents, who were still in high school, remained stable. Among the older cohort respondents only, school connectedness was associated with subsequent positive perceptions about local job prospects net of relevant controls. Same-age cohort comparisons, evaluated when each cohort was in 12th-grade, showed no differences in the short-term effects of school connectedness on perceived local job prospects, despite variations in the age-linked timing of the most dramatic rise in unemployment during the study. The results highlight the lasting importance of school connectedness for teens raised in struggling rural economies.     

Greenhouse affect: the relationship between the sustainable design of schools and children’s environmental attitudes

This study aims to determine if primary school children’s environmental attitudes can be predicted by whether their school had been designed or adapted for sustainability. A New Ecological Paradigm (NEP) scale for children was adopted to measure attitudes, with supplementary questions added to align this scale to the Australian context of the study. In addition, the original adult NEP scale was used to determine relationships between children’s environmental attitudes, their School Design and their Parents’ and Teachers’ Environmental Attitudes. Data collected from grade 4, 5 and 6 primary school children, their parents and teachers were analysed via three multiple regressions. The results indicate that sustainable design in schools improves the environmental attitudes of children towards perceptibly green building features, such as solar panels, the use of recycled water, natural daylighting and outdoor classrooms including food-producing gardens.     

Gene-environment contributions to the development of infant vagal reactivity: the interaction of dopamine and maternal sensitivity

This study investigated dopamine receptor genes (DRD2 and DRD4) and maternal sensitivity as predictors of infant respiratory sinus arrhythmia (RSA) and RSA reactivity, purported indices of vagal tone and vagal regulation, in a challenge task at 3, 6, and 12 months in 173 infant-mother dyads. Hierarchical linear modeling (HLM) revealed that at 3 and 6 months, RSA withdrawal in response to maternal separation was greater (suggesting expected physiological regulation) in infants without the DRD2 risk allele than those with the risk allele. At 12 months, infants with the risk allele who were also exposed to maternal sensitivity showed levels of RSA withdrawal comparable to infants who were not at genetic risk. Findings demonstrate the importance of developmental analysis of gene-environment interaction.     

Understanding teacher instructional change: the case of integrating NGSS and stewardship in professional development

The environmental education (EE) field has encountered persistent challenges in fostering the integration of EE practices in public schools, a challenge that may be addressed through integration of EE with the Next Generation Science Standards (NGSS) in the United States. In addition to the potential for fostering EE, the integration of EE and NGSS may provide a unique set of conditions for understanding how and why teachers shift their practice to incorporate more EE in their classrooms. Using a mixed methodology research design, this study examines the outcomes and processes of a professional development institute that integrated NGSS and student-driven environmental stewardship. This study provides evidence that integrating NGSS Science and Engineering Practices with stewardship may help infuse EE into classrooms. The research also contributes to theoretical understanding of the processes by which professional development shapes teacher change within an organizational context. Specifically, teacher instructional change was predicated on a shift in their beliefs that stewardship was possible in a standards and accountability-based educational context. The requisite shift in beliefs came about through the expectations and supportive resources provided by the professional development, teacher observation of student engagement, and the justification NGSS integration provided for stewardship activities.     

Exploring the Co‐Development of Reading Fluency and Reading Comprehension: A Twin Study

This study explores the co‐development of two related but separate reading skills, reading fluency and reading comprehension, across Grades 1–4. A bivariate biometric dual change score model was applied to longitudinal data collected from 1,784 twin pairs between the ages of 6 and 10 years. Grade 1 skills were influenced by highly overlapping genetic and environmental factors. Growth in both skills was influenced by highly overlapping shared environmental factors. Cross‐lagged parameters indicated bidirectional effects, with stronger effects from fluency to comprehension change than from comprehension to fluency change.     

Muscle co-activation and its influence on running performance and risk of injury in elite Kenyan runners

The relationship between muscle co-activation and energy cost of transport and risk of injury (initial loading rate and joint stiffness) has not been jointly studied. Fourteen elite Kenyan male runners were tested at two speeds (12 and 20 km · h^?1), where oxygen consumption, kinematic, kinetic and electromyography were recorded. Electromyography of seven lower limb muscles was recorded. Pre-activation and ground contact of agonist:antagonist co-activation was determined. All muscles displayed higher activity during pre-activation except rectus femoris (RF). Conversely, no differences were found during ground contact except for higher biceps femoris (BF) at 20 km · h^?1. Knee stiffness was correlated to RF–BF co-activation during both pre-activation and ground contact at both running speeds. However, energy cost of transport was only positively correlated to the above-mentioned muscle pairs at 20 km · h^?1 (r = 0620, P = 0.032; r = 0.682, P = 0.015, respectively). These findings emphasise the influence of neuromuscular control and performance and its support to musculoskeletal system to optimise function and modulate risk of injury. Further, neuromuscular activity during terminal swing is also important and necessary to execute and maintain performance.