The asymmetry of pectoralis muscles is greater in male prepubertal than in professional tennis players

It is generally accepted that preadolescents have a limited capacity to develop muscle hypertrophy in response to exercise compared with older populations; however, studies are scarce and conflicting. The main aim of the present study was to assess if playing tennis is associated with the hypertrophy of dominant pectoralis muscles (PM) in professional (PRO) and in prepubescent tennis players (PRE). A secondary aim was to assess if the degree of asymmetry of PM is greater in PRO than PRE. The volume of PM of both sides was determined using magnetic resonance imaging in 8 male PRO (21.9 years), 6 male PRE (11 years, Tanner 1–2) and 12 male non-active controls (6 adults: 23.5 years; and 6 prepubescents: 10.7 years, Tanner 1–2). PRO and PRE had 15 and 30% greater volume, respectively, in the dominant than in the contralateral PM (P?P?=?.34 in adults and 5%, P?=?.17 in children). The degree of side-to-side asymmetry in PM volume was greater in PRE than in PRO (P?相似文献   

Performance of goldfish trained in allocentric and egocentric maze procedures suggests the presence of a cognitive mapping system in fishes

Goldfish were trained to obtain food in a four-arm maze placed in a room with relevant spatial cues. Four experimental conditions were run: allocentric, egocentric, egocentric + allocentric, and control. Relative to controls, all groups were able to solve the different tasks with high accuracy after 1 week of training. Subsequent transfer tests revealed place and response strategies for allocentric and egocentric groups, respectively, and both types of strategies for the ego-allocentric group. Moreover, the allocentric group showed the capacity to choose the appropriate trajectory toward the goal, even from novel starting points, presumably by using the distal cues as a whole. The results suggest that, in addition to using egocentric strategies, goldfish are able to solve spatial tasks on the basis of allocentric frames of reference and to build complex spatial cognitive representations of their environment.     

Legitimating the world-class university concept through the discourse of elite universities’ presidents†

Although well-renowned universities attempt to differentiate themselves from other universities, little research has been undertaken on the principal themes involved in the concept of the world-class university (WCU) as presented in speeches by members of WCUs. These discourses are a key tool in universities’ attempt to shape the competitive framework of higher education through legitimacy. We study the presidents’ discourses from 100 leading universities to identify the themes and emergent discourse of these universities’ communities. Applying topic modeling methodology to the speeches’ corpus, we find seven communities (Worldwide-the four regions, American-from different states, Flagship, Education concerned, Some Chinese universities, Central European universities and Challengers) and four main themes arising from WCUs’ discourses (Research universities within international rankings, Stakeholders and leadership, Mission and values, and Education). Our preliminary findings suggest that leading universities are working to adopt the WCU label based on their salient characteristics.     

Incommensurability and Multiple Models: Representations of the Structure of Matter in Undergraduate Chemistry Students

The notion of incommensurability has provided a rationality criterion for the development of scientific theories, as well as some insight into theories developed by students while learning science. However, the relationship between the multiple models held by students and incommensurability requires further discussion. We present the results of empirical work that investigated the multiple models of the structure of the matter held by university students and we analyze these results using the notion of incommensurability. We also point out implications in the construction of students’ scientific models as they move forward in their careers.     

Separated by Removal: The Impact of Parental Deportation on Latina/o Children’s Postsecondary Educational Goals

This research examines the impact of parental deportation on Latino/a adolescents’ postsecondary aspirations. Based on interviews with students, their families, and site observations, the study finds that for some adolescents who held college aspirations prior to the deportation, this type of abrupt parental removal negatively affects their perception of safety and stability in their home and school environments (i.e., microsystem) (Bronfenbrenner, 2005). Where this vulnerability is not countered with emotional, economic, and institutional support, it can hinder their development of the social capital (Coleman, 1988; Stanton-Salazar, 2001) that would be conducive to their higher educational aspirations.     

The influence of lexical and sublexical variables in normal and poor Spanish readers

The main aim of our study was to find out the effect of several lexical and sublexical variables (lexical category, lexical frequency, syllabic structure, and word length) in the acquisition of reading in a transparent language such as Spanish. The second goal of our study was the comparison of the effect of these variables in normal and poor Spanish readers. One hundred and forty children (aged between 6 and 12), twenty of whom were poor readers, were tested using a reading test of 306 items in which we balanced all the variables. The dependent variable was the percentage of correct responses in a decontextualized word reading test. Our results showed that all the above mentioned variables produced a significant effect on the number of errors made by the children. This pattern of results suggests no difference between the processes involved in the reading acquisition of Spanish and those implicated in deep orthographies such as English. Our results also showed no qualitative differences between normal and poor readers. The four variables studied showed the same behaviour in their effect on reading performance for both normal and poor readers, indicating that poor readers also use both the lexical and the phonological route. Our data suggest the universality of the dual route model, independent of the transparency or opaqueness of the different alphabetical languages.     

Communicative functions during the pre-grammatical stage: a case study / Las funciones comunicativas durante la etapa pregramatical: un estudio de caso

This study contributes empirical evidence regarding communicative functions in the pre-grammatical period. The aim was to explore these functions in child-adult dyadic interactions during what in language acquisition research has been called the two-word period. The study draws from the data corpus of a child 19–29 months old and the system of sign categories (gestures, non-verbal vocalizations, verbal vocalizations, uni- and bimodal compositions) developed by Rodríguez & Español. In order to study the communicative functions in this period, an observational code was developed in accordance with Strauss and Corbin’s Constant Comparative Method, which is suitable for encompassing the entire repertoire of a child’s sign use. The study in general allowed some functions absent in adult communication to be identified, and the qualitative analysis in particular revealed a use of semiotic resources that supports the idea of a cognitive processing structure common to gesture and word.     

Literacy practices of primary education children in Andalusia (Spain): A family-based perspective

Primary school children develop literacy practices in various domains and situations in everyday life. This study focused on the analysis of literacy practices of children aged 8–12 years from the perspective of their families. 1,843 families participated in the non-experimental explanatory study. The children in these families speak Spanish as a first language and are schooled in this language. The instrument used was a self-report questionnaire about children's home-literacy practices. The data obtained were analysed using categorical principal components analysis (CATPCA) and analysis of variance (ANOVA). The results show the complex relationship between literacy practices developed by children in the domains of home and school and the limited development of a literacy-promoting ‘third space’. In conclusion, the families in our study had limited awareness of their role as literacy-promoting agents and thought of literacy learning as restricted to formal or academic spaces.