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1.
This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L?1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L?1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L?1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL?1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L?1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L?1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.  相似文献   
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Twenty acquisition curves were obtained from each of 8 pigeons in a free-operant choice procedure. Every condition began with a phase in which two response keys had equal probabilities of reinforcement, and, as a result, subjects’ responses were divided fairly evenly between the two keys. This was followed by a phase in which one key had a higher probability of reinforcement than the other, and the development of preference was observed. In all but a few cases, response proportions increased for the key with the higher probability of reinforcement. In most conditions, the two probabilities differed by .06, but the actual probabilities varied (from .16 and .10 in one condition to .07 and .01 in another). Development of preference for the key with the higher probability of reinforcement was slower when the ratio of the two reinforcement probabilities was small (.16/.10) than when it was large (.07/.01). This finding is inconsistent with the predictions of several different quantitative models of acquisition, including the kinetic model (Myerson & Miezin, 1980) and the ratio-invariance model (Horner & Staddon, 1987). However, the finding is consistent with a hypothesis based on Weber’s law, which states that the two alternatives are more discriminable when the ratio of their reinforcement probabilities is larger, and, as a result, the acquisition of preference is faster.  相似文献   
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Abstract

Literature on American Indian student support in postsecondary education illustrates the importance of relationality in creating a positive college experience for Native students. That said, much of the literature examining ‘care relationships’ in Indian education focuses on student outcomes, with less attention given to the experiences of practitioners. Thus, the purpose of this paper is twofold. First, the author examines where and how American Indian higher education practitioners learned principles of communal care for supporting Indigenous students in non-Native postsecondary institutions. Second, she explores how these principles act as homesteads of mutuality to love, transform, resist, and enact refusal within the academy. She draws upon the literature on American Indian student support in postsecondary education, which illustrates the importance of relationality in creating a positive college experience for Native students.  相似文献   
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Each of the fields of geriatrics and interdisciplinary practice intensifies the usefulness and effectiveness of the other. Combining geriatrics and interdisciplinary practice also magnifies the complexity of two singularly complex fields. However, the subtle reasons for their complexity may escape the understanding of clinicians, educators, policy makers, and administrators. Attempting to treat older patients who have complex problems while ignoring common principles of geriatrics and teamwork can cause a kind of double jeopardy. It can potentially harm the patient and decrease the provider's sense of mastery. Training either students or health care providers to appreciate the interactions and the complexities of these two fields could produce a double indemnity for the health care system and for older persons who need health care. It requires recognizing subtle factors like the barrier of presumed knowledge, the interpretation of the meaning of function, frailty, the lure of medical technology, professional hierarchies, diverse views of disease, and the myth of insufficient evidence.  相似文献   
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Infant social–emotional development may be impacted by the COVID-19 pandemic. This study investigated associations between maternal pre- and postnatal pandemic-related concerns and social–emotional developmental risk. Data, collected in 2020–2021, came from 220 mothers (87% white, 6% Hispanic, 1% Black, 3% Asian, 1% American Indian, Mage = 32.46 years), and infants (53.18% male, Mage = 12.98 months) in the United States. Maternal postnatal pandemic-related concerns were associated with total risk scores (B = 6.09, p-value <.001) and offspring risk of scoring positive for problems related to inflexibility (B = 4.07, p-value = .006). The total score association was moderated by self-reported social support. Infants may be detrimentally impacted by the pandemic via maternal pandemic-related concerns. Maternal social support may buffer infants.  相似文献   
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Government-led interorganizational alliance networks present a sensible opportunity to overcome many societal challenges through collaborative governance. In particular, few researchers have studied alliance networks in the field of energy conservation in commercial buildings—a sector with unique barriers to greater diffusion of innovative cost-saving strategies. We applied an analytic inductive case-based method and social network analysis to study one particular alliance network: the United States Commercial Building Energy Alliances representing interests from retail, commercial real estate, and healthcare sectors. This alliance network was initiated by the United States Department of Energy, with assistance from several federally funded research laboratories in the United States, to promote the diffusion of knowledge and ultimately encourage greater deployment of energy efficiency and clean energy strategies in commercial buildings. We draw upon interview data from 28 cases of private, non-profit, and governmental organizations and complete network data from the alliance participants. We honed in on eight focal cases of governmental organizations to provide insight on how the four forms of energy and environmental data, information, and knowledge shared within an alliance network address the challenge of a vastly underutilized energy resource, namely conservation. Further, we identify and discuss the public's four roles—Commissioner, Interpreter, Marketer, and User—in providing balance to the diffusion of both private and public goods in a network.  相似文献   
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