1,819 research outputs found
Orientaciones de meta en las clases de educación física : un análisis centrado en la educación secundaria obligatoria
This paper explores the subject of motivation in educational environments, more specifically in physical education. The research study it describes is based on the concept of goal perspectives (Nicholls, 1984, Dweck and Legget, 1988, Ames, 1984, Duda, 1992), and the purpose of the study was to identify the (task or ego) goal orientations shown by secondary school students in physical education classes, together with any possible differences based either on gender or the academic stage in the students education. The sample was composed of 203 secondary school students who all answered the POSQ questionnaire. From the results that were obtained, both goal orientations were observed, with a task-basedorientation predominating. It was also shown that boys are more ego oriented than girls
Análisis de la estructura genética de poblaciones del caracol rosado, Strombus gigas (L.) en la Peninsula de Yucatán
Treating hummingbirds as feathered bees : a case of ethological cross-pollination
Hummingbirds feed from hundreds of flowers every day. The properties of these flowers provide these birds with a wealth of information about colour, space and time to guide how they forage. To understand how hummingbirds might use this information, researchers have adapted established laboratory paradigms for use in the field. In recent years, however, experimental inspiration has come less from other birds, and more from looking at other nectar-feeders, particularly honeybees and bumblebees, which have been models for foraging behaviour and cognition for over a century. In a world in which the cognitive abilities of bees regularly make the news, research on the influence of ecology and sensory systems on bee behaviour is leading to novel insights in hummingbird cognition. As methods designed to study insects in the laboratory are being applied to hummingbirds in the field, converging methods can help us identify and understand convergence in cognition, behaviour and ecology.PostprintPeer reviewe
Migration policies in dynamic island models
Dynamic island models are population-based algorithms for solving optimization problems, where the individuals of the population are distributed on islands. These subpopulations of individuals are processed by search algorithms on each island. In order to share information within this distributed search process, the individuals migrate from their initial island to another destination island at regular steps. In dynamic island models, the migration process evolves during the search according to the observed performance on the different islands. The purpose of this dynamic/adaptive management of the migrations is to send the individuals to the most promising islands, with regards to their current states. Therefore, our approach is related to the adaptive management of search operators in evolutionary algorithms. In this work, our main purpose is thus to precisely analyze dynamic migration policies. We propose a testing process that assigns gains to the algorithms applied on the islands in order to assess the adaptive ability of the migration policies, with regards to various scenarios. Instead of having one dynamic migration policy that is applied to the whole search process, as it has already been studied, we propose to associate a migration policy to each individual, which allows us to combine simultaneously different migration policies
Fungal microbiota from rain water and pathogenicity of Fusarium species isolated from atmospheric dust and rainfall dust
In order to determine the presence of Fusarium spp. in atmospheric dust and rainfall dust, samples were collected during September 2007, and July, August, and October 2008. The results reveal the prevalence of airborne Fusarium species coming from the atmosphere of the South East coast of Spain. Five different Fusarium species were isolated from the settling dust: Fusarium oxysporum, F. solani, F. equiseti, F. dimerum, and F. proliferatum. Moreover, rainwater samples were obtained during significant rainfall events in January and February 2009. Using the dilution-plate method, 12 fungal genera were identified from these rainwater samples. Specific analyses of the rainwater revealed the presence of three species of Fusarium: F. oxysporum, F. proliferatum and F. equiseti. A total of 57 isolates of Fusarium spp. obtained from both rainwater and atmospheric rainfall dust sampling were inoculated onto melon (Cucumis melo L.) cv. Piñonet and tomato (Lycopersicon esculentum Mill.) cv. San Pedro. These species were chosen because they are the main herbaceous crops in Almeria province. The results presented in this work indicate strongly that spores or propagules of Fusarium are able to cross the continental barrier carried by winds from the Sahara (Africa) to crop or coastal lands in Europe. Results show differences in the pathogenicity of the isolates tested. Both hosts showed root rot when inoculated with different species of Fusarium, although fresh weight measurements did not bring any information about the pathogenicity. The findings presented above are strong indications that long-distance transmission of Fusarium propagules may occur. Diseases caused by species of Fusarium are common in these areas. They were in the past, and are still today, a problem for greenhouses crops in Almería, and many species have been listed as pathogens on agricultural crops in this region. Saharan air masses dominate the Mediterranean regions. The evidence of long distance dispersal of Fusarium spp. by atmospheric dust and rainwater together with their proved pathogenicity must be taken into account in epidemiological studies
A multivariate approach for the ampelographic discrimination of grapevine (Vitis vinifera) cultivars: application to local Syrian genetic resources
Due to its unique historical and geographical emplacement, grapes have been cultivated in the Syrian Arab Republic for more than 5000 years, so the characterization of its local genetic resources is paramount for understanding grapevine natural diversity. In this work, different local Syrian table grape cultivars were characterized for 42 traits related to plant phenology, shoot, leaf, cluster, berry and juice composition. A series of multivariate analyses were sequentially performed, and five highly-discriminant traits were identified as the most discriminant ones (shoot internode length, berry weight, berry elongation, 100-seed weight and juice titratable acidity). The clustering of the cultivars according to these five traits revealed that some local Syrian cultivars share similitude with some worldwide grown cultivars, suggesting their potential as new genetic resources for the development of new high-quality table grape varieties, and indicating the needing of specific preservation programs aimed to avoid the loss of endangered genetic local resources. Besides, the statistical multivariate pipeline followed in this work is proposed as an efficient one for the selection of ampelographic traits for the discrimination of grapevine cultivars.(VLID)233169
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