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排序方式: 共有319条查询结果,搜索用时 15 毫秒
121.
Faming Wang Christian J Sanders Isaac R Santos Jianwu Tang Mark Schuerch Matthew L Kirwan Robert E Kopp Kai Zhu Xiuzhen Li Jiacan Yuan Wenzhi Liu Zhi'an Li 《国家科学评论(英文版)》2021,8(9)
Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52–59.01) Tg C yr−1, which is ∼30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios. 相似文献
122.
Diana A. Santos Adilson Marques Cláudia S. Minderico Ulf Ekelund 《Journal of sports sciences》2018,36(15):1720-1726
Cardiorespiratory fitness (CRF) is associated with health benefits in children, improving cardiac morphology, cardiovascular disease risk factors, and biological outcomes. This study aimed to examine the substitution effects of displaying a fixed duration of sedentary time with a fixed duration of physical activity (PA) at different intensities on children’s CRF. A total of 315 children (136 boys) were assessed (age: 10.6 ± 0.6 years old). Outcomes at baseline and follow-up (16-months) were CRF determined using a maximal cycle test and sedentary time and PA measured with accelerometers. Data were analysed by isotemporal substitution analyses estimating the effect of reallocating 30 min/day of sedentary time by light (LPA), moderate (MPA) and vigorous physical activity (VPA) on CRF. VPA was positively and significantly associated with CRF cross-sectional (β = 0.026, p < 0.001) and prospectively (β = 0.010, p < 0.001). Reallocating 30 min/day of sedentary time into VPA was positively cross-sectionally (β = 0.780, p < 0.001) and prospectively (β = 0.303, p < 0.05) associated with CRF. Conversely, relocating 30-minutes of sedentary time into 30 minutes of LPA and MPA was not associated with CRF. These results suggest that reallocating an equal amount of time from sedentary into VPA is cross-sectional and prospectively associated with a favourable CRF. 相似文献
123.
Sofia Nyström 《Vocations and Learning》2009,2(1):1-18
This paper explores the development of professional identity as a relationship between professional and personal aspects of life. The focus is on student and novice professional psychologists’ and political scientists’ processes of professional identity formation in their transition from higher education to working life. Drawing on Wenger’s theory of nexus of multimembership (1998), the findings indicate that professional identity is a dynamic relationship between different life spheres rather than an isolated phenomenon only taking place at the university or in the work context. The analysis yielded three different forms of professional identity, non-differentiated identity, compartmentalised identity and integrated identity, which exemplify different negotiated relationships between professional, personal and private life spheres. The findings show that these three forms of professional identities are sequential, from an individual focus to more relational and integrated ways of reasoning about one’s profession. It is through the negotiations between personal and socially derived imperatives that identity formation progresses throughout working lives. 相似文献
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126.
Bárbara Filipa Casqueria Coelho Gabriel João Alexandre Dias-de-Oliveira Victor Fernando Santos Neto António Gill D’Orey De Andrade-Campos 《European Journal of Engineering Education》2018,43(6):950-966
Methodologies for engineering learning and teaching (MELT) approach aims to enhance the attractiveness of education through science, technology, engineering and mathematics (STEM) among young people, while promoting awareness of future careers in these areas. To this end, students’ expectations are considered within university programmes, aiming to an increased engagement in STEM careers. To accomplish these goals, a new and integrated approach (MELT) is presented, involving the main stakeholders in both scientific education and society. An education framework is presented, providing guidelines for an improved collaborative approach to STEM education in the future. Results from the pilot implementation of MELT are presented, from a small-scale education parliament prototype. From these initial stage and results, it is seen that there is a need for a proper alignment of expectations from all involved stakeholders, concerning the engineering education towards society’s demands. 相似文献
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128.
Jorge R. Sanchez Frankie Santos Laanan W. Charles Wiseley 《Research in higher education》1999,40(1):87-113
In the wake of new federal and state mandates,community colleges are faced with demands to provideaccountability reports on student outcomes. With the useof the Employment Development Department Unemployment Insurance (EDD-UI) wage record data, along withthe California Community Colleges Chancellor's OfficeManagement Information System administrative database,this study sought to investigate the extent to which completing an associate degree andvocational certificate impacts the postcollege earningsof students. Based on information from 700,564 studentsfrom California community colleges during the 1992-93 academic year, the findings suggest thatstudents' gains from first year out of college to thirdyear out will differ by age group. Among economicallydisadvantaged students, a strong positive relationship exists between educational attainment andpostcollege gains. An important finding among vocationalstudents is that as women complete more education, theearnings gap closes between men and women. Finally, this study raises several policy implicationsand presents suggestions for future research. 相似文献
129.
Juliano Dal Pupo Daniele Detanico Jonathan Ache-Dias Saray Giovana dos Santos 《Journal of sports sciences》2017,35(1):81-88
This study aimed to investigate the fatigue effects induced by a futsal-specific protocol (FIRP) on sprint performance and the kinematics of the lower limbs. Twenty-one futsal players participated in this study and performed a protocol to simulate the futsal demands. At pre-protocol, half-time and post-protocol, the athletes performed 10-m sprints that were recorded for kinematic analysis. Continuous relative phase (CRP) was calculated to assess the inter-segmental coordination. In addition, vertical (KVERT) and leg (KLEG) stiffness were calculated. Analysis of variance (ANOVA) for repeated measures was used (P < 0.05). The main results showed that sprint time increased (P < 0.01) post-protocol when compared to pre- and half-time conditions. Lower values of the step rate (P = 0.01) and higher values of the leg angular velocity (P = 0.02) were verified at the end of the FIRP. The CRP of thigh–leg and leg–foot and the stiffness did not change over the protocol. In addition, the high correlation of CRP between the conditions revealed no changes in coordination pattern. We concluded that futsal related-fatigue induced a decrement on sprint time, changing the kinematics of the lower limbs (decreasing step rate and increasing leg angular velocity). However, neither stiffness nor intersegment coordination during sprints was affected by fatigue. 相似文献
130.
In outdoor activities, it seems reasonable that the longer children spend in spontaneous physical activity (PA), the higher the probability of being active. Indeed, the time spent outdoor has been identified as a variable consistently associated with the children’s PA. Outdoor playing, such as the organized sports practice, appears associated with healthier lifestyle standards. All the recommendations mention the importance of increasing daily PA practice in children and teenagers, but few studies highlight the relationship between outdoor play and the recommended PA levels. The purpose of this study is to investigate the relationships between the frequency of outdoor play, the frequency of the organized sports practice, and the compliance of the recommendations for PA practice in children in the inner city area of Porto. The sample of this study is composed of 422 individuals (mean age of 11.6 years). Two hundred and twenty-five of them were girls and 197 were boys from the sixth grade (elementary schools located in the inner city area of Porto). PA was objectively evaluated using accelerometers. Participants reported frequency of participation in different PA contexts, such as sports practice and outdoor play. The results show a predictor effect of participating in sports three or more times per week on compliance of PA guidelines.In conclusion, organized sports practice seems more effective than outdoor play to reach the recommended levels of PA in children. 相似文献