鸟类的亲缘关系研究

有些看似迥然不同的鸟类实际上是久违的亲戚,比如鲜艳的蜂鸟和褐色的欧夜莺。有些鸟类从未被联想在一起,但的确是近亲,例如鸣鸟和鹦鹉。其他行为习惯相似的鸟类．比如隼和其他食肉猛禽,则可能在基因上毫无瓜葛。     

American Association for Health,Physical Education,and Recreation

ABSTRACT

Purpose: The purpose of this study was to identify whether post-resistance exercise (REx) blood flow restriction (BFR) can elicit a similar acute training stimulus to that offered by either heavy REx or traditional low-load BFR REx. Method: Ten men completed trials with 30% one-repetition maximum (1RM) for 5 sets of 15 repetitions without BFR (30%), with BFR during exercise (30% RD), and with postexercise BFR (30% RP) and at 75% 1RM for 3 sets of 10 repetitions. Lactate and cortisol were measured before and up to 60 min after exercise. Thigh circumference, ratings of perceived exertion (RPE), and pain were measured before and after exercise. Surface electromyography was measured during exercise. Results: All conditions had a large effect (effect size [ES] > 0.8) on lactate, with the largest effects observed with the 75% condition; no differences were observed between the 30% conditions. All conditions had a moderate effect (ES > 0.25 ≤ 0.4) on increasing thigh circumference. This effect was maintained (ES = 0.35) with the application of BFR after REx (30% RP). Change in RPE, from the first to last set, was significantly greater with 30% RD compared with other conditions (all p < .05). Electromyography amplitude was higher and percentage change was greater for the 75% condition compared with the other conditions (both p < .05). Conclusions: The application of BFR immediately post-REx altered several of the responses associated with REx that is aimed at inducing muscular hypertrophy. Additionally, these changes occurred with less pain and perceived exertion suggesting that this form of REx may offer an alternative, tolerable method of REx.     

Innovation intermediaries and collaboration: Knowledge–based practices and internal value creation

This paper analyses how knowledge-based practices adopted by innovation intermediaries enable them to generate value for themselves when collaborating with their clients. While the literature focuses on value creation for their client organisations, little is known about how innovation intermediaries create internal value even though this is essential for ensuring their long-term survival and sustaining their key facilitating role in the innovation system. This understudied issue is explored using empirical evidence from a sub-set of innovation intermediaries, Research and Technology Organisations (RTOs). The results indicate that by capitalising on existing knowledge vested in employees and collaborators as well as understanding and shaping the knowledge base of the innovation ecosystem, innovation intermediaries generate internal value from their involvement in collaborative innovation, which range from different financial to non-financial types of value. Implications for intermediaries, their collaborators and for policymakers are then discussed.     

Cowboys, scientists, and fossils: the field site and local collaboration in the American West

Even as the division between professional scientists and laypeople became sharper by the end of the nineteenth century, the collaboration of local people remained important in scientific fieldwork, especially in sciences such as vertebrate paleontology that required long-term extractive access to research sites. In the North American West, the competition between museums and universities for the best fossil quarry sites involved negotiations with locals. The conflict over differing conceptions of the field site is vividly demonstrated through an examination of one site on the High Plains of western Nebraska in the early twentieth century. This case offers a rare opportunity to see not only how professionals regarded such sites but also how the resident ranching family, the Cooks, attempted to exercise leverage over the scientific fieldwork that took place there. While the Carnegie Museum of Pittsburgh became mired in protracted conflict with the Cooks over discovery claims and the ongoing control of the site, the University of Nebraska and the American Museum of New York developed more harmonious relations with the site's resident ranching family.     

ANALYZING MATH‐TO‐MASTERY THROUGH BRIEF EXPERIMENTAL ANALYSIS

The current study evaluated the effectiveness of individualized math‐to‐mastery (MTM) interventions, selected though brief experimental analysis (BEA), at increasing math fluency skills for three elementary‐aged females. As MTM has only been investigated as a multicomponent intervention, the present study utilized BEA to identify those specific components that led to math skills gains in the most efficient manner possible. BEA results indicated that for two of three participants only a partial MTM intervention was necessary to prompt fluency gains, while the entire intervention was the most effective for the third. During extended analysis all three participants displayed math skills gains above those seen during repeated baseline assessments. Results are discussed in terms of further refining MTM through BEA procedures so as to individually target math skill deficits by considering both intervention effectiveness and efficiency.     

Learning Disability Identification Criteria and Reporting in Empirical Research: A Review of 2001–2013

This review documents the learning disabilities (LD) identification criteria and procedures utilized in empirical research including students with LD published from 2001 to 2013 in three journals dedicated to the study of LD. Results reveal several troublesome findings related to transparency in reporting and the coherence of the LD construct. Nearly one‐third of all empirical studies investigating LD did not describe who identified the participants as having LD or how they were identified. Information on the specific area of LD was similarly lacking. Across studies, identification criteria varied widely. Moving forward, we contend that greater transparency and consistency with regard to the definition and operationalization of the construct of LD in empirical research is necessary if solidification of the scientific construct of LD is to be achieved.