237 research outputs found
Diving lice: The exception to the rule that there are no insects in the (deep) ocean
Insects are present in virtually all possible habitats on the mainland but virtually absent in the ocean which constitutes 90% of the biosphere. Only a few species are present in the sea, but remaining at the surface, salt marshes, estuaries, or shallow waters. Remarkably, a group of species manages to endure long immersion periods in the open sea, as well as deep dives, i.e. seal lice. We discuss here some of the adaptations that allow seal lice to cope with the amphibious habits of their hosts and how they can help understanding why are insect so rare in the ocean.Fil: Leonardi, María Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Crespo, José Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Soto, Florencia Anabella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Biología de Organismos Marinos; ArgentinaFil: Lazzari, Claudio R.. Universite de Tours; Francia. Centre National de la Recherche Scientifique; FranciaThe 1st International Electronic Conference on EntomologySuizaInsects JournalMultidisciplinary Digital Publishing Institut
Mixing thermodynamics and photocatalytic properties of GaP-ZnS solid solutions
Preparation of solid solutions represents an effective means to improve the photocatalytic properties of semiconductor-based materials. Nevertheless, the effects of site-occupancy disorder on the mixing stability and electronic properties of the resulting compounds are difficult to predict and consequently many experimental trials may be required before achieving enhanced photocatalytic activity. Here, we employ first-principles methods based on density functional theory to estimate the mixing free energy and the structural and electronic properties of (GaP)x(ZnS)1-x solid solutions, a representative semiconductor-based optoelectronic material. Our method relies on a multi-configurational supercell approach that takes into account the configurational and vibrational contributions to the free energy. Phase competition among the zinc-blende and wurtzite polymorphs is also considered. We demonstrate overall excellent agreement with the available experimental data: (1) zinc-blende emerges as the energetically most favorable phase, (2) the solid solution energy band gap lies within the 2-3 eV range for all compositions, and (3) the energy band gap of the solid solution is direct for compositions x < 75%. We find that at ambient conditions most (GaP)x(ZnS)1-x solid solutions are slightly unstable against decomposition into GaP- and ZnS-rich regions. Nevertheless, compositions x = 25, 50, and 75% render robust metastable states that owing to their favorable energy band gaps and band levels relative to vacuum are promising hydrogen evolution photocatalysts for water splitting under visible light. The employed theoretical approach provides valuable insights into the physicochemical properties of potential solid-solution photocatalysts and offers useful guides for their experimental realization
Zero-lag long-range synchronization via hippocampal dynamical relaying
2 páginas, 1 figura.-- Póster presentado al Nineteenth Annual Computational Neuroscience Meeting: CNS*2010
San Antonio, TX, USA; 24-30 July 2010.Peer reviewe
Using target enrichment sequencing to study the higher-level phylogeny of the largest lichen-forming fungi family: Parmeliaceae (Ascomycota)
Parmeliaceae is the largest family of lichen-forming fungi with a worldwide distribution. We used a target enrichment data set and a qualitative selection method for 250 out of 350 genes to infer the phylogeny of the major clades in this family including 81 taxa, with both subfamilies and all seven major clades previously recognized in the subfamily Parmelioideae. The reduced genome-scale data set was analyzed using concatenated-based Bayesian inference and two different Maximum Likelihood analyses, and a coalescent-based species tree method. The resulting topology was strongly supported with the majority of nodes being fully supported in all three concatenated-based analyses. The two subfamilies and each of the seven major clades in Parmelioideae were strongly supported as monophyletic. In addition, most backbone relationships in the topology were recovered with high nodal support. The genus Parmotrema was found to be polyphyletic and consequently, it is suggested to accept the genus Crespoa to accommodate the species previously placed in Parmotrema subgen. Crespoa. This study demonstrates the power of reduced genome-scale data sets to resolve phylogenetic relationships with high support. Due to lower costs, target enrichment methods provide a promising avenue for phylogenetic studies including larger taxonomic/specimen sampling than whole genome data would allow
Kissing molars extraction: case series and review of the literature
Kissing molars are a very rare form of inclusion defined as molars included in the same quadrant, with occlusal
surfaces contacting each other within a single dental follicle.
We present four cases of this pathology: a 35 year-old male, referred to the Oral and Maxillofacial Surgery Department of the Hospital Virgen del Rocio in Seville, and three females of 24, 26, and 31 years, all of which had
kissing molars that were treated by tooth extraction.
We have found only 10 cases published in the medical literature in which this type of inclusion is briefly described,
none of which elaborate on the surgical technique employed. In these cases, the indication for surgery is established
when there is a history of recurring infections or cystic lesions associated with dental inclusions. The extraction of
kissing molars requires an exhaustive comprehension of the anatomy of the region involved, sufficiently developed
surgical abilities, and an extensive planning proces
La relación del liderazgo educacional con la ciencia-tecnología-sociedad y sus dimensiones/The relationship of educational leadership with science-technology-society and its dimensions
Los directores de las instituciones educativas poseen insuficiencias en su desempeño que dificultan su influencia consciente sobre sus subordinados. El objetivo de la investigación es valorar la relación del liderazgo educacional con la ciencia, la tecnología y la sociedad desde sus dimensiones. Se tuvieron en cuenta los resultados de excelencia a partir de experiencias prácticas en el desempeño de los directores de escuelas del municipio Morón en Ciego de Ávila, Cuba, en un período de cinco años (2012-2017), además se utilizaron métodos del nivel teórico, empíricos y de procesamiento matemático; se ofrecen conclusiones precisas sobre el proceso de formación del liderazgo en los directores de escuelas
Internal Carotid Artery Reconstruction with a “Mega Flow Diverter”: First Experience with the 6×50 mm DERIVO Embolization Device
Endoluminal reconstruction with a flow diverter device has emerged as a viable and often preferable alternative to traditional techniques for the treatment of intracranial aneurysms. Precise measurement and device selection are mandatory steps when considering flow diverters usage in order to avoid potential complications. In this sense, incomplete wall-apposition has been described as a predictive factor for immediate in-stent and delayed thrombosis after stent use. One significant usage limitation of flow diverter devices is the parent artery diameter, since the maximum opening of the sizes available are recommended for vessel diameters between 5.2–5.75 mm. Here we present the first clinical use of the largest flow diverter available, the 6×50 mm DERIVO embolization device (Acandis GmbH & Co. KG, Pforzheim, Germany), into the arterial circulation for a cervical internal carotid artery endovascular reconstruction. This is a new device for large or fusiform aneurysms requiring flow diversion, especially located in the vertebrobasilar system or extracranial segments
Bullying in Brazilian schools: results from the National School-based Health Survey (PeNSE), 2009
O objetivo deste estudo é identificar e descrever a ocorrência do bullying, episódios de humilhação ou provocação perpetrados pelos colegas da escola, entre estudantes do 9º ano do ensino fundamental de escolas públicas e privadas das 26 capitais dos estados brasileiros e do Distrito Federal. Trata-se de estudo transversal feito com 60.973 escolares de 1.453 escolas públicas e privadas. A análise dos dados aponta que 5,4% (IC95%: 5,1%-5,7%) dos estudantes relataram ter sofrido bullying quase sempre ou sempre nos últimos 30 dias; 25,4% (IC95%: 24,8%-26,0%) foram raramente ou às vezes vítimas de bullying e 69,2% (IC95%: 68,5%-69,8%) não sentiram nenhuma humilhação ou provocação (bullying). A capital com maior frequência de foi Belo Horizonte-MG (6,9%; IC95%: 5,9%-7,9) e a menor foi Palmas-TO (3,5%; IC95%: 2,6%-4,5%). Meninos relatam mais bullying (6,0%; IC95%: 5,5%-6,5%) do que meninas (4,8%; IC95%: 4,4%-5,3%). Não houve diferença entre escolas públicas (5,5%; IC95%: 5,1%-5,8%) e privadas (5,2%; IC95%: 4,6%-5,8%), exceto em Aracaju-SE, onde foi registrada maior ocorrência de bullying em escolas privadas. Os dados mostram urgente necessidade de ações intersetoriais a partir de políticas e práticas educativas que efetivem redução e prevenção da ocorrência do bullying nas escolas.The aim of this study is to identify and describe the occurrence of bullying among students in the 9th year (8th grade) from public and private schools from 26 Brazilian state capitals and the Federal District. It is a cross-sectional study involving 60,973 students and 1,453 public and private schools. Data analysis indicates that 5.4% (IC95%: 5.1%-5.7%) of students reported having suffered bullying almost always or always in the last 30 days, 25.4% (IC95%: 24.8%-26.0%) were rarely or sometimes the victim of bullying and 69.2% (IC95%: 68.5%-69.8%) of students felt no humiliation or provocation at school. The capital with higher frequency of bullying was Belo Horizonte (6.9%; IC95%: 5,9%-7,9%), Minas Gerais, and the lowest was Palmas (3.5%; IC95%: 2.6%-4.5%), Tocantins. Boys reported more bullying (6,0%; IC95%: 5.5%-6.5%) compared with girls (4,8%; IC95%: 4.4%-5.3%). There was no difference between public schools 5.5% (IC95%: 5.1%-5.8%) and private (5.2%) (IC95%: 4.6%-5.8%), except in Aracaju, Sergipe, that show more bullying in private schools. The findings indicate an urgent need for intersectoral action from educational policies and practices that enforce the reduction and prevention of the occurrence of bullying in schools in Brazil
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