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Suzana Matheus Pereira Caroline Ruschel Marcel Hubert Leandro Machado Helio Roesler Ricardo Jorge Fernandes 《Journal of sports sciences》2015,33(19):2006-2015
This study aimed to analyse the kinematic, kinetic and electromyographic characteristics of four front crawl flip turn technique variants. The variants distinguished from each other by differences in body position (i.e. dorsal, lateral, ventral) during rolling, wall support, pushing and gliding phases. Seventeen highly trained swimmers (17.9 ± 3.2 years old) participated in interventional sessions and performed three trials of each variant, being monitored with a 3-D video system, a force platform and an electromyography (EMG) system. Studied variables: rolling time and distance, wall support time, push-off time, peak force and horizontal impulse at wall support and push-off, centre of mass horizontal velocity at the end of the push-off, gliding time, centre of mass depth, distance, average and final velocity during gliding, total turn time and electrical activity of Gastrocnemius Medialis, Tibialis Anterior, Biceps Femoris and Vastus Lateralis muscles. Depending on the variant, total turn time ranged from 2.37 ± 0.32 to 2.43 ± 0.33 s, push-off force from 1.86 ± 0.33 to 1.92 ± 0.26 BW and centre of mass velocity during gliding from 1.78 ± 0.21 to 1.94 ± 0.22 m · s?1. The variants were not distinguishable in terms of kinematical, kinetic and EMG parameters during the rolling, wall support, pushing and gliding phases. 相似文献
105.
A. Zaher S. Li K. T. Wolf F. N. Pirmoradi O. Yassine L. Lin N. M. Khashab J. Kosel 《Biomicrofluidics》2015,9(5)
Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices'' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source. 相似文献
106.
Ashleigh M. Day Sydney O’Shay-Wallace Matthew W. Seeger Shawn P. McElmurry 《Communication Studies》2019,70(3):352-376
Safe, clean water is necessary for health and well-being. Water issues affect minority and vulnerable populations at disproportionate rates, including the poor and racial and ethnic minorities. An investigation of the relationships of race, social media use, and informational sources during the municipal water crisis in Flint, Michigan, reflects an instrumental view of communication and uses and gratifications theory in this study. Data from 208 Flint residents in 2016 indicated that African American respondents favored interpersonal networks and resources and were more likely than other racial groups to obtain current information about the water crisis via Instagram. Preferred channels and sources to receive additional crisis information varied on the basis of race. 相似文献
107.
Benjamin Gonzalez O’Brien Elizabeth Hurst Loren Collingwood 《Mass Communication and Society》2019,22(6):756-778
The refugee sanctuary movement in the United States has shifted to include undocumented immigrants fleeing violence and economic strife. Given the negative tenor of coverage of undocumented immigration, and ties between framing and policy views on immigration, how the media frames sanctuary cities is likely to impact public perceptions of these cities and their policies. To assess media coverage of sanctuary policies, we analyzed articles from five national newspapers from 1980 to 2017 with both human content analysis and dictionary-based computational analysis. We find that framing around religion/morality and conflict has decreased, while stories focusing on crime and partisanship have increased. We discuss implications for public opinion and the likelihood that the American public will take their cues from media framing and elite discourse when it comes to sanctuary policies. 相似文献
108.
Neil O’Boyle 《International Studies in Sociology of Education》2015,25(2):93-111
Research finds that participation in higher education is generally empowering for mature students but that it can also create tensions in their off-campus relationships. This article reports on findings from an ongoing study of the experiences of mature students at university in Ireland and draws from interviews with 15 such students in the final year of their studies. Following similar research by Baxter and Britton in the UK, the article considers how mature students experience and represent changes in identities and social relationships brought about by entry to higher education. Specifically, the article focuses on the risks associated with using newly acquired academic language (or ‘university speak’) off campus. The findings reported here complement existing research and offer support for Baxter and Britton’s suggestion that mature students often experience compartmentalisation and fragmentation in their self-identities. 相似文献
109.
Emmanuel O’Grady 《Cambridge Journal of Education》2015,45(2):167-185
Interpersonal respect is a fundamental aspect of relating to others. This is especially true for teachers, as cultivating relationships is implicit in effective teaching. This three-year qualitative study examines a developing understanding of respect for pre-service teachers that progresses on to their first year’s teaching to examine the influential factors on that understanding. These teachers’ pupils were also asked to comment on their perceptions of respect. The findings indicate that interpersonal respect in an educative relationship is influenced by the level of autonomy afforded pupils and minimising the power differential between teachers and pupils. 相似文献
110.
John O’Rourke John West 《International Journal of Disability, Development & Education》2015,62(5):531-546
Education assistants (EAs) who support students with disability in general education classrooms often find themselves in difficult situations. Caught in the firing line between their personal sense of duty, expectations of the classroom teachers, and the challenges that inclusion presents, their roles as primary support agents are anything but clear. In the following article the authors describe the findings from a modification of screening tool on the over-utilisation of paraprofessionals. The 16-item electronic survey focused on factors associated with EA support, conducted in a variety of Western Australian schools. The findings revealed that school community members such as EAs, classroom teachers, administrators and parents observed aspects of EA support that appear counter-productive towards more inclusive pedagogy. 相似文献