Differences in the utilisation of active power in squat and countermovement jumps     

Damián Ferraro  Gabriel Fábrica 《European Journal of Sport Science》2017,17(6):673-680

The aim of this article was to understand how active power is used in squat and countermovement jumps. A simple empirical model comprising a mass, a spring, an active element and a damper, together with an optimisation principle, was used to identify the mechanical factors that maximise performance of jumps without countermovement (squat jumps, SJ) and with countermovement (CMJ). Twelve amateur volleyball players performed SJ from two initial positions and CMJ with two degrees of counterbalancing, while kinematic data were collected (jump height, push-off duration and position of the centre of mass). The model adjusted well to real data of SJ through all the impulse phase, and slightly less adequately at the end of this phase for CMJ. Nevertheless, it provides a satisfactory explanation for the generation and utilisation of active power for both type of jumps. On average, the estimated power of the active elements, the spring, and the damper were greater in the SJ. Based upon the result obtained with this model, we suggest that active power is best evaluated with SJ. The reason for this is that, during this kind of jump, the elements associated with the damper consume much of the energy produced by the active elements. The participation of the elements that consume the energy generated by the active elements is less in CMJ than in SJ, allowing for a better utilisation of this energy. In this way it is possible to achieve a better performance in CMJ with less active power.  相似文献   

Facilitating Intercultural Communication in Parent–Teacher Conferences: Lessons From Child Translators     

Inmaculada M. García–Sánchez  Marjorie Faulstich Orellana  Megan Hopkins 《Multicultural Perspectives》2013,15(3):148-154

In this article Abraham Lincoln is considered as an alternative to the usual type of patriot's hero. He reminds us of our great historical failings. He remains a figure of controversy, a national hero in only some corners of society. He is the heroic President who serves as the first compassionate defender of the downtrodden, and he is a hero in those subcultures as well. Lincoln's treatment in the movies is discussed, focusing particularly on the recent movie Lincoln. Lincoln is seen as a match for the usual movie hero. His famous immunity to casual treatment in popular culture is discussed as well.  相似文献   

Geological risk assessment for cultural heritage conservation in karstic caves     

Eneko Iriarte  Miguel Ángel Sánchez  Alberto Foyo  Carmen Tomillo 《Journal of Cultural Heritage》2010,11(3):250-258

The increasing awareness of some local and international authorities has promoted the appearance of new legislation and the rising of research works focused in the prevention of damage to the cultural heritage in karstic caves. Nevertheless, karstic areas usually imply complex studies, and a universal methodology is very difficult to establish. This work exposes the basic methodology for the geological risk assessment in archaeological site and/or rock art bearing karstic caves getting a strategy that provides flexibility to adjust specific methods according to the conditions of different cases. The integrated use of basic geological (mapping, petrology, stratigraphy…) and geotechnical (rock mass quality analytical methods and indexes) techniques used in engineering geology is proposed. Those techniques permit the geological characterization of the rock mass, the hazard identification and the analysis and the geological risk assessment of the research area. Obtained geological risk areas could be included in protection areas that could be used as the basis for the selection of the areas where further investigations and the application of prevention/mitigation measures would have a better cost/benefit ratio. The geological risk should be considered together with other type risk evaluations in order to define effective protection areas.  相似文献   

A survey on the light-fastness properties of organic-based Alaska Native artifacts     

Julio M. del Hoyo-Melndez  Marion F. Mecklenburg 《Journal of Cultural Heritage》2010,11(4):48-499

A series of light-fastness tests were conducted on a group of ethnographic objects that will be on exhibit at the Smithsonian Institution Arctic Studies Center, a recent addition to the Anchorage Museum at Rasmuson Center in Alaska. The objects surveyed belong to the collections of the Smithsonian National Museum of Natural History and the Smithsonian National Museum of the American Indian. This work was designed as a feasibility study on the use of a micro-fading tester as a non-contact and non-destructive technique to evaluate the light-stability of materials present in ethnographic collections. A broad range of objects containing a wide variety of materials were selected for the study. The materials investigated included a variety of dyes applied on silk, cotton, and wool substrates along with some unusual materials such as tanned skin and seal gut skin. The results from this investigation have allowed establishing exhibition recommendations taking into consideration the sensitivity of each object, light levels in the museum building, and estimated light exposures based on the duration of the exhibit. The micro-fading tester has proven to be a very useful tool for determining the light-stability of ethnographic materials without causing any harm to the objects. Objects containing equivalent materials are usually classified under a general category based on their probable sensitivity to light. However, micro-fading test results have permitted the detection of dissimilarities among some of these objects, which could be associated to variations in prior fading histories, the quality of raw materials, and different preparation methods.  相似文献   

English-Spanish Cognates and the Pura Belpré Children's Award Books: Reading the Word and the World     

José A. Montelongo  Anita C. Hernández  Roberta J. Herter 《Multicultural Perspectives》2014,16(3):170-177

English-Spanish cognates are an important subset of words in both the English and Spanish languages. Cognates are words that possess identical or nearly identical spellings and meanings in both languages as a result of being derived from Latin and Greek. Of major importance is the fact that many of the more than 20,000 cognates in English are academic vocabulary words, terms essential for comprehending school texts.

?The Pura Belpré Children's Book Award has been given since 1996 to outstanding children's and young adult literature that represents, affirms, and celebrates the Latino cultural experience. The books are judged for their literary and artistic quality.

?There are many English-Spanish cognates in each of the Pura Belpré picture books. The purpose of this article is to introduce the Pura Belpré Cognate Database, which lists all of the English-Spanish cognates for each of the children's picture books that have won the award or have been designated as honor books. Ideas for vocabulary, spelling, and morphology lessons or mini-lessons are also presented.  相似文献   

Construction of Critically Transformative Education in the Tucson Unified School District     

Augustine F. Romero  H. T. Sánchez 《Multicultural Perspectives》2014,16(4):240-244

A critically transformative education continues to be at the center of Tucson Unified School District's (TUSD) equity and academic excellence mission. Through the use of the Social Transformation paradigm and the lesson learned from the implementation of the Critically Compassionate Intellectualism Model, TUSD once again created a cutting edge transformative, cultural, ethnic, multicultural, equity-based curricula that seeks to stimulate the blossoming intellectual capacities of our students. It presents the opportunity to build foundations and structures of collective and individual agency. Along the lines of agency, it promotes what is called barriorganic intellectualism and the nurturing of gardens of intellectualism (jardines del intelectualismo) that provide opportunities for both the academic and personal transformation of our students.  相似文献   

Perceived benefits and barriers to the use of high-speed broadband in Ireland's second-level schools     

Bryan Coyne  Niamh Devitt  Seán Lyons 《Irish Educational Studies》2013,32(4):355-378

As part of Ireland's National Digital Strategy, high-speed broadband is being rolled out to all second-level schools to support greater use of information and communication technology (ICT) in education. This programme signals a move from slow and unreliable broadband connections for many schools to a guaranteed high-speed connection with technical support. Theoretically, this should allow for behaviours and pedagogies to adapt, incorporating ICT into education. Research shows that integrating ICT into teaching and learning is a gradual process for most teachers and is influenced by a complex mix of socio-technical factors. Our data set consists of survey data from teachers and principals from a sample of second-level schools. The survey collected factual and attitudinal variables including attitudes towards ICT integration, current availability of infrastructure and barriers to ICT use, before schools received high-speed broadband connectivity. We examine the factors influencing teachers’ attitudes to ICT and their perceived barriers in adopting new technologies in their day-to-day teaching. Analysis of this baseline period is essential in an iterative digital strategy, informing future strategies, targeting policy most effectively and achieving policy objectives. While attitudes towards the potential of high-speed broadband and use of ICT are consistently positive across sub groups of schools and teachers, perceived barriers to ICT usage differ.  相似文献   

Science teachers' knowledge about and attitudes towards the use of models and modelling in learning science     

Rosária S. Justi  John K. Gilbert 《International Journal of Science Education》2013,35(12):1273-1292

A semi-structured interview was used to enquire into the knowledge of models and modelling held by a total sample of 39 Brazilian science teachers working in 'fundamental' (ages 6-14 years) and 'medium' (ages 15-17 years) schools, student teachers, and university teachers. This paper focuses on their perceptions of the role of models in science teaching. The teachers' ideas are organized in three groups: the status and value of models; the influences that inform the translation of these general ideas into classroom practice; and how they respond to the outcomes of students' modelling activities. The teachers interviewed generally showed an awareness of the value of models in the learning of science but not of their value in learning about science. They were also uncertain of the relationship that could exist in the classroom between various types of models. Modelling, as an activity by students, whilst praised in theory, would not seem to be widely practised. Where practised, the outcomes are by no means always treated with that integrity that learning about science would call for.  相似文献   

Heather E. Douglas: Science, Policy, and the Value-Free Ideal     

José Luis Luján 《Science & Education》2013,22(4):873-875

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Spanish renaissance cosmography: modest or modern?     

Fernández-Armesto  Felipe 《Metascience》2010,19(1):147-148

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