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We examined the effect of short-term heat acclimation with permissive dehydration (STHADe) on heat acclimation (HA) and cycling performance in a temperate environment.

Purpose: It has been suggested that dehydration is an independent stimulus for heat acclimation (HA), possibly through influencing fluid-regulation mechanisms and increasing plasma volume (PV) expansion. There is also some evidence that HA may be ergogenic in temperate conditions and that this may be linked to PV expansion. We investigated: (i) the influence of dehydration on the time-course of acquisition and decay of HA; (ii) whether dehydration augmented any ergogenic benefits in temperate conditions, particularly those related to PV expansion.Methods: Eight males [VO2max: 56.9(7.2) mL·kg−1·min−1] undertook two HA programmes (balanced cross-over design), once drinking to maintain euhydration (HAEu) and once with restricted fluid-intake (HADe). Days 1, 6, 11, and 18 were 60 min exercise-heat stress tests [HST (40°C; 50% RH)], days 2–5 and 7–10 were 90 min, isothermal-strain (Tre ~ 38.5°C), exercise-heat sessions. Performance parameters [VO2max, lactate threshold, efficiency, peak power output (PPO)] were determined pre and post HA by graded exercise test (22°C; 55%RH).Results: During isothermal-strain sessions hypohydration was achieved in HADe and euhydration maintained in HAEu [average body mass loss −2.71(0.82)% vs. −0.56(0.73)%, P < 0.001], but aldosterone concentration, power output, and cardiovascular strain were unaffected by dehydration. HA was evident on day 6 {reduced end-exercise Tre [−0.30(0.27)°C] and exercise heart rate [−12(15) beats.min−1], increased PV [+7.2(6.4)%] and sweat-loss [+0.25(0.22) L.h−1], P < 0.05} with some further adaptations on day 11 {further reduced end-exercise Tre [−0.25(0.19)°C] and exercise heart rate [−3(9) beats.min−1], P < 0.05}. These adaptations were not notably affected by dehydration and were generally maintained 7-days post HA. Performance parameters were unchanged, apart from increased PPO (+16(20) W, irrespective of condition).Conclusions: When thermal-strain is matched, permissive dehydration which induces a mild, transient, hypohydration does not affect the acquisition and decay of HA, or endurance performance parameters. Irrespective of hydration, trained individuals require >5 days to optimize HA.

Chronic exposure to a stressor elicits adaptations enhancing the tolerance to that stressor. These adaptive responses might also improve tolerance under less stressful conditions. For example, historically there has been much interest in the adaptive responses to high-altitude, or hypoxia, and their ergogenic potential under sea-level, or normoxic, conditions. In contrast, the influence of the adaptive responses to heat on exercise under cooler conditions has received relatively little interest. Heat acclimation/acclimatization (HA) is known to increase work capacity in hot environments. Yet, aerobic exercise performance can progressively deteriorate as ambient temperature increases beyond ~10 °C, indicating a thermal limitation even under relatively cool conditions. The improved thermoregulatory capability induced by HA might attenuate this thermal decrement in a manner similar to that seen when exposed to hotter temperatures. Moreover, the suite of adaptations elicited by HA has the potential to increase maximal oxygen uptake, lactate threshold and economy, and thus may be ergogenic even under conditions where performance is not thermally limited. Indeed, evidence is now emerging to support an ergogenic effect of HA but the number of studies is limited and in some instances lack appropriate control, are confounded by methodological limitations, or do not address the mechanisms of action. Nevertheless, these tantalising insights into the ergogenic potential of heat will likely generate considerable interest in this new 'hot topic'. Future research will need to employ well-designed studies to clarify the exercise conditions under which ergogenic effects of HA are apparent, to elucidate the precise mechanisms, and to optimise HA strategies for performance.

This study responds to such shortcomings by analyzing relational interactions in urban elementary mathematics classrooms in tandem with content instruction of teachers who engage in supportive relationships with African American and Latin@ students. This study identified teachers with high quality student performance, content instruction, and supportive relationships as defined through relational interactions. After selecting two teachers, the results detail relational interactions that show how these teachers established supportive relationships with students vis-à-vis their mathematics instruction. Therefore, these findings offer insight into the ways in which relational interactions add to our understanding of quality content instruction for African American and Latin@ students.

The construct of culture has been largely invisible In the research and long-standing debates in the learning disabilities (LD) field, such as those pertaining to the definition of LD and how research knowledge is used in local settings. When used, the idea of culture tends to be defined as unrelated to LD and studied as restricted to individual/group traits. We challenge the culture-LD dichotomy and the limited conception of culture used in this knov^ledge base. For this purpose, v^e make the case for a cultural model of learning that can inform scholarship about the nature of LD, and we propose a culturebased model for the study of research knov^^ledge use in professional practices. Moreover, we offer a third perspective on culture to study the strategies that the LD research community might be using to demarcate and maintain a cultureless paradigm of LD. Our discussion offers potentially rich opportunities for a culturally minded and reflexive stance in the LD field that is urgently needed in our increasingly diverse society.

Background and Aims: The evaluation of breathing function is crucial in the clinical examination of the respiratory system. The Total Faulty Breathing Scale (TFBS) could be used in clinical settings to quantify the measurement of breathing dysfunction.Reliability data for the TFBS are available for males, but there is a requirement to determine reliability for females and to develop reference values. The aim of this study, therefore, was to determine the reliability in females and to establish the preliminary reference values for the TFBS.Methods: Twenty-three healthy female participants for reliability and 44 (7 male and 37 female) participants for preliminary reference values participated in this cross-sectional study. For both aspects of the study, participants were instructed to breathe at their own pace with no specific instruction. Then each participant was observed carrying out normal breathing for a period of 10 breaths and deep breathing for a period of 10 breaths while being assessed with the TFBS.Results: Intrarater and interrater reliability of the TFBS showed a kappa value of 0.769 and 0.751, respectively, indicating substantial agreement for female participants. The preliminary reference categories for TFBS were reported to be normal for 20 (45.5%) participants and mild faulty breathing for the remaining 24 (54.4%) participants. Conclusions:The findings of this study suggested that TFBS was reliable to measure breathing function among female participants, and the reference categories may be helpful in the identification of normal and faulty breathing.