754 research outputs found

    Surface magnetization in non-doped ZnO nanostructures

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    We have investigated the magnetic properties of non-doped ZnO nanostructures by using {\it ab initio} total energy calculations. Contrary to many proposals that ferromagnetism in non-doped semiconductors should be induced by intrinsic point defects, we show that ferromagnetism in nanostructured materials should be mediated by extended defects such as surfaces and grain boundaries. This kind of defects create delocalized, spin polarized states that should be able to warrant long-range magnetic interactions.Comment: 8 pages, 3 figure

    GEMINI: A Generic Multi-Modal Natural Interface Framework for Videogames

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    In recent years videogame companies have recognized the role of player engagement as a major factor in user experience and enjoyment. This encouraged a greater investment in new types of game controllers such as the WiiMote, Rock Band instruments and the Kinect. However, the native software of these controllers was not originally designed to be used in other game applications. This work addresses this issue by building a middleware framework, which maps body poses or voice commands to actions in any game. This not only warrants a more natural and customized user-experience but it also defines an interoperable virtual controller. In this version of the framework, body poses and voice commands are respectively recognized through the Kinect's built-in cameras and microphones. The acquired data is then translated into the native interaction scheme in real time using a lightweight method based on spatial restrictions. The system is also prepared to use Nintendo's Wiimote as an auxiliary and unobtrusive gamepad for physically or verbally impractical commands. System validation was performed by analyzing the performance of certain tasks and examining user reports. Both confirmed this approach as a practical and alluring alternative to the game's native interaction scheme. In sum, this framework provides a game-controlling tool that is totally customizable and very flexible, thus expanding the market of game consumers.Comment: WorldCIST'13 Internacional Conferenc

    Nesting in the lizard Phyllopezus pollicaris (Squamata: Phyllodactylidae) and a phylogenetic perspective on communal nesting in the family

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    Ninhadas comunais são encontradas em várias espécies de répteis. As hipóteses que explicam a evolução desse comportamento ainda são controversas, mas serão melhor compreendidas à medida que mais registros de ninhadas comunais forem descritos na literatura. Neste estudo, registramos duas ninhadas comunais de Phyllopezus pollicaris, incluindo a maior ninhada conhecida para a espécie. Este é o primeiro estudo a registrar ninhadas comunais para uma espécie de Squamata em uma região central do Cerrado. Além disso, também apresentamos fotografias das ninhadas, assim como medidas detalhadas e peso dos neonatos. As ninhadas foram encontradas durante a estação seca, em contraste com o padrão reprodutivo previamente descrito para a espécie na periferia do Cerrado. Nós também realizamos uma extensa revisão bibliográfica a respeito de ninhadas comunais na família Phyllodactylidae e apresentamos os resultados no contexto de uma árvore filogenética dos gêneros da família. Finalmente, sugerimos que estudar a correlação entre a evolução de ninhadas comunais e o investimento reprodutivo se tornará um campo de estudo fértil à medida que mais informações sobre ninhadas comunais estiverem disponíveis na literatura científica.Communal nesting occurs in many reptile species. The hypotheses that explain the evolution of such behaviours are still controversial, but will be better understood as more communal nesting records are described in the literature. We report the findings of two communal nests of Phyllopezus pollicaris, including the largest known nest for the species. Our study is the first to provide a communal nesting record for squamate species in a Cerrado core area. We provide nest photographs and detailed neonate measurements and weight. Nests were found during the dry season, in contrast with the reproduction pattern previously described for the species in the Cerrado periphery. We also conducted an extensive literature review seeking all available information on communal nesting information in Phyllodactylidae, and present this information in the context of a phylogenetic tree of phyllodactylid genera. We suggest that studying the correlation between communal nesting evolution and reproductive investment will become a fertile field as more information on lizard nesting becomes available in the literature

    Prevalence of conventional cardiovascular risk factors in patients with acute coronary syndrome

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    Background: Primary prevention studies have shown that early detection and aggressive treatment of cardiovascular risk factors (CRF) prevent cardiovascular events. It is not well described the prevalence of CRF in patients, at the moment of admission due to acute coronary syndrome (ACS). Aim: To determine the prevalence of CRF among patients admitted with ACS. Methods: We analysed 4871 patients admitted consecutively in our coronary care unit with a diagnosis of ACS and included in a prospective registry, from January 2002 to October 2013. We studied the prevalence of conventional risk factors (diabetes, hypertension, smoking, dyslipidaemia) and compared findings according to gender and type of ACS: ACS with ST elevation (STEMI), ACS without ST elevation (NSTEMI). Results: Men represented 75% (n=3658) of the total population, were younger than women (61.6±12,9 vs 70.9 ±11.8 years; p<0.001) and had more frequently body mass index ≥ 25 kg/m2 (70.9% vs 62.3%; p<0.001). The most frequent CRF was hypertension (62.4%; n=3038), followed by dyslipidaemia (50.6%, n=2467), smoking (43.2%; n=2106) and diabetes (27.2%; n=1324). In women, the more common CRF were hypertension (75%) and dyslipidaemia (51.2%), whereas in men were smoking (54.4%) and dyslipidaemia (50.5%). We identify, at least, one CRF in 92,4% of all patients and two or three risk factors in 58.1%. Women had more frequently 2 CRF than men (40.1% vs 36.3%; p=0.011), although mean had, more often, 4 CRF (8.9% vs 4.1%; p<0.001). Previous history of cerebrovascular disease was more observed in women (8.6% vs 6.1%; p=0.002), but men had more often history of previous revascularization (9.8% vs 6.8%; p<0.001). On admission men presented more frequently STEMI (50.8% vs 43.5%; p<0,001) and less frequently renal dysfunction (17.2% vs 39.6%; p<0.001) and anaemia (18.8% vs 33.3%; p<0.001). Hypertension was the most prevalent CFR as in patients STEMI (56.6%) as in NSTEMI patients (67.9%), followed by smoking (47.5%) in STEMI patients and by dyslipidaemia (55.7%) in NSTEMI patients. Conclusion: We found at least one CRF in 92.8% of patients and two or three in more than half. Hypertension emerged as the major CRF in both forms of presentation of ACS
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