793 resultados para Communication in science.


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The effect of pheromones and their chemical analogues in honeybee alarm behaviors was studied in observation boxes. Defensive behaviors, as follows: a) attraction to scent source, b) elevation of wings in 'V', c) abdomen elevation, d) abdomen elevation and pumping and e) first leg pair elevation had been temporarily registered when the following compounds were presented: isoamyl alcohol, octyl alcohol, benzyl alcohol, n-butyl acetate, n-octyl acetate, isopentyl acetate, benzyl acetate and 2-heptanone. The results were as follows: 1. the bees elicited some characteristic behaviors when chemical alarm messages were presented, 2. agression (stinging) was not completed with any compound tested, probably because there was not a target (visual stimulus), 3. in all situations the attraction to scent source was low, 4. all the behaviors were elicited in a temporarily different way, 5. the compounds that elicited stronger responses and a greater number of the investigated behaviors were: isopentyl acetate, 2-heptanone, octyl acetate and n-octyl alcohol. In all situations, the first behavior response (and the most intense one) was the elevation and pumping the abdomen. This suggests that the chemical message was promptly recognized and then transmitted to each worker. So, the results obtained in the present work, suggest that chemical alarm messages may be recognized by different mechanisms of neural integration.

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AIM: This in vitro study evaluated the abrasiveness of acidic fluoride (F) dentifrices with different F concentrations on bovine enamel. METHODS: Enamel blocks (4.0 x 4.0 mm2, n=120) were selected according to their surface microhardness and divided into 12 groups. Slurries of dentifrices were used containing 0 (placebo), 275, 412, 550 and 1,100 ppm F (pH 4.5 or 7.0), as well as testing two commercial dentifrices (Crest, positive control, 1,100 ppm F and Colgate Baby, 500 ppm F). Enamel blocks were partially protected with an adhesive tape (control area) and then brushed by an automated toothbrushing machine (16,000 strokes). During this process, 0.4 ml of the slurries were injected every 2 mins on the enamel blocks. After toothbrushing, enamel wear was determined by profilometry. STATISTICS: Results were analyzed by ANOVA and Tukey's test (p<0.05). RESULTS: The mean values for pH in the suspensions during treatment were 6.93, 4.32, 7.56 and 8.19 for neutral experimental dentifrices, acidic experimental dentifrices, Crest and Colgate baby, respectively. The abrasiveness of the acidic dentifrices was similar (p<0.05) to the neutral ones, whereas commercial dentifrices yielded lower abrasion (p<0.05). CONCLUSION: It was concluded that a reduction of the pH of dentifrices does not increase their abrasiveness.

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The effects of ethanol exposure on Danio rerio have been studied from the perspectives of developmental biology and behavior. However, little is known about the effects of ethanol on the prey-predator relationship and chemical communication of predation risk. Here, we showed that visual contact with a predator triggers stress axis activation in zebrafish. We also observed a typical stress response in zebrafish receiving water from these conspecifics, indicating that these fish chemically communicate predation risk. Our work is the first to demonstrate how alcohol effects this prey-predator interaction. We showed for the first time that alcohol exposure completely blocks stress axis activation in both fish seeing the predator and in fish that come in indirect contact with a predator by receiving water from these conspecifics. Together with other research results and with the translational relevance of this fish species, our data points to zebrafish as a promising animal model to study human alcoholism. © 2013 Oliveira et al.

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Incluye el temario, la lista de participantes y las ponencias de las agencias que auspician las actividades en ciencia y tecnologia en la region, presentadas en la reunion efectuada el dia anterior a la tercera sesion plenaria del Consejo del Caribe para la Ciencia y la Tecnologia.

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Contiene informacion sobre el Proyecto III del programa de trabajo del CCCT: preparacion e intercambio de material audiovisual para la educacion sobre los beneficios, limitaciones y peligros del desarrollo en ciencia y tecnologia.

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Presenta las recomendaciones para evitar la duplicacion de esfuerzos en la implementacion y fortalecimiento de la colaboracion en ciencia y tecnologia entre las agencias especializadas y los proyectos que deberian llevarse a cabo ya que el resultado de ellos puede ser la base para una mayor colaboracion entre los paises miembros del CCCT.

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The importance of science and technology (S&T) in Small Island Developing States (SIDS) is clearly articulated in Chapter XI, paragraphs 57, 58, 61 and 62 of the Mauritius Strategy for the Further Implementation of the Programme of Action for Sustainable Development of Small Island Developing States (MSI). At the regional level, the Heads of Government of the Caribbean Community (CARICOM) noted the challenge that CARICOM member States face in competing in this new international economic environment in which the impact of scientific and technological change has created a knowledge-based global economy. Given the importance of S&T to development of Caribbean SIDS, the Economic Commission for Latin America and the Caribbean (ECLAC) Subregional Headquarters for the Caribbean embarked on a study to determine the causes and consequences of low rates of specialisation in S&T with a view to making recommendations for development of strategies for addressing these challenges. Data on postgraduate (Master of Science, Master of Philosophy and Doctor of Philosophy) enrolment and graduation in agriculture, engineering and the sciences from the three campuses of the University of the West Indies (UWI) as well as from the University of Technology in Jamaica and the University of Trinidad and Tobago (UTT) were examined and analysed. Face-to-face interviews were also held with key personnel from these institutions and a questionnaire was also served to individuals in key institutions. Results of the study revealed that although the number of students enrolled in higher degree programmes has increased in absolute terms, they are decreasing in relative terms. However, enrolment in agriculture has indeed declined while enrolment rates in engineering, although increasing, were not significantly high. Market forces have proved to be a main reason for this trend while facilities for the conduct and supervision of cutting-edge research, the disconnect between science and industry and societal labelling of scientists as “misfits” are also contributing to the situation. This has resulted in a reduced desire by students at all levels of the school system and faculty to be involved in S&T; lack of innovation; a better staffed private, as compared with public, sector; and poor remuneration in science-based employment. There also appears to be a gender bias in enrolment with more males than females being enrolled in engineering while the opposite is apparent in agriculture and the sciences. Recommendations for remedying this situation range from increasing investment in S&T, creating linkages between science and industry as well as with the international community, raising awareness of the value of S&T at all levels of the education system to informing policy to stimulate the science innovation interface so as to promote intellectual property rights.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)