511 research outputs found
Parallel, linear-scaling building-block and embedding method based on localized orbitals and orbital-specific basis sets
We present a new linear scaling method for the energy minimization step of
semiempirical and first-principles Hartree-Fock and Kohn-Sham calculations. It
is based on the self-consistent calculation of the optimum localized orbitals
of any localization method of choice and on the use of orbital-specific basis
sets. The full set of localized orbitals of a large molecule is seen as an
orbital mosaic where each tessera is made of only a few of them. The orbital
tesserae are computed out of a set of embedded cluster pseudoeigenvalue coupled
equations which are solved in a building-block self-consistent fashion. In each
iteration, the embedded cluster equations are solved independently of each
other and, as a result, the method is parallel at a high level of the
calculation. In addition to full system calculations, the method enables to
perform simpler, much less demanding embedded cluster calculations, where only
a fraction of the localized molecular orbitals are variational while the rest
are frozen, taking advantage of the transferability of the localized orbitals
of a given localization method between similar molecules. Monitoring single
point energy calculations of large poly(ethylene oxide) molecules and three
dimensional carbon monoxide clusters using an extended Huckel Hamiltonian are
presented.Comment: latex, 15 pages, 10 figures, accepted for publication in J.Chem.Phy
El cerebro triuno y la inteligencia ética: matriz fundamental de la inteligencia multifocal
This study has for aim offer an analysis as for the brain triuno and the ethical intelligence: fundamental Counterfoil of the multifocal intelligence, taking in tells one of the theories that it sustains her like they are the different types of multiple intelligences established by Beauport and Cury (2004). The theoretical sustenance, it is based on the contents of Martin (2005), Belohlavek (2007), Galicians (2002), Beauport and Cury (2004), between others, being realized under a symbolic interpretive approach, across a qualitative methodology, type descriptive and not experimental design, by means of a documentary analysis. In this regard, it is found that the ethical intelligence is a mental mechanism that constructs the structural preconceptos and the rules of game with which an individual approaches the reality, that is to say, it is the capacity of the general formation, predicting the behavior for the achievement of aims organizacionales. As for the final considerations they focused in obtaining the most wide knowledge inside the organizations, allowing to reflect before the weaknesses that they present thinking about the brain triuno applying the multifocal intelligence, fundamental counterfoil of the ethical intelligence and of what way the rationing visualizes the strengths, nevertheless of the weaknesses that they present.Este estudio tiene por objetivo ofrecer un análisis sobre el cerebro triuno y la inteligencia ética, matriz fundamental de la inteligencia multifocal, tomando en cuenta una de las teorías que la sustentan como son los diferentes tipos de inteligencias múltiples establecidas por Beauport y Cury (2004). El sustento teórico está basado en los contenidos de Martín (2005), Belohlavek (2007), Gallegos (2002), Beauport y Cury (2004), entre otros. El estudio se realiza bajo un enfoque simbólicointerpretativo por medio de una metodología cualitativa de tipo descriptiva y diseño no experimental, mediante un análisis documental. A este respecto se establece que la inteligencia ética es un mecanismo mental que construye los preconceptos estructurales y las reglas de juego con que un individuo aborda la realidad, es decir, es la capacidad de la formación general, prediciendo el comportamiento para el logro de objetivos organizacionales. Las consideraciones finales se enfocan en obtener el conocimiento más amplio dentro de las organizaciones, permitiendo recapacitar ante las debilidades que se presentan, reflexionando sobre el cerebro triuno aplicando la inteligencia multifocal, matriz fundamental de la inteligencia ética y de qué manera el razonamiento visualiza las fortalezas, no obstante las debilidades que se presenten
Firewood and timber exploitation during the third and second millennia BC in Northwestern Iberia: wood resources, territories and chaîne opératoire
Human societies established productive strategies in order to obtain the material resources needed for their day‐to‐day life, including firewood and timber. These strategies were determined by the environmental supply, and also by the cultural characteristics and technical capacities of these communities.
This paper presents charcoal analysis data from four Chalcolithic and Bronze Age open‐air settlements located in the northwest of the Iberian Peninsula and occupied during the third and second millennia BC. These results contribute to the knowledge of the exploitation of wooden resources, of the territories where these resources were collected, and of the firewood and timber production process. The identified wood taxa point to a diversified exploitation of the territory, where firewood and timber were collected and/or felled in the deciduous woodland, the river banks and scrubland areas. The characteristics of the wood elements used, the degree of growth ring curvature, the minimum diameter of twigs or logs, etc., as well as other data from archaeological contexts, such as the length of the postholes, were all taken into account to establish hypotheses related to the operative chaine of forest resources. The wooden resources consumed in each site allowed us to hypothesize about the territory of each community.As sociedades humanas estabelecem toda uma série de estratégias produtivas destinadas a
obter os meios materiais necessários para a sua existência, entre elas, o aprovisionamento de lenha e
de madeira. Estas estratégias, além de estarem condicionadas pela oferta ambiental, são igualmente
resultantes das caraterísticas culturais e das capacidades técnicas das comunidades.
Os dados arqueobotânicos que se apresentam procedem de vários lugares de habitação do Calcolítico
e da Idade do Bronze da fachada ocidental do Noroeste peninsular com cronologias que abarcam o 3º
e parte do 2º milénios AC. Os resultados obtidos permitiram identificar uma exploração diversificada
dos recursos lenhosos que combinava a recolha de lenha e de madeira da floresta climácica com
a proveniente das áreas de mato. As formações arbóreas situadas nas margens dos cursos de água
também constituíram fonte de aprovisionamento de combustíveis e, provavelmente, de madeira.
A análise dendrológica das amostras registando o grau de curvatura dos anéis de crescimento anual, o diâmetro mínimo dos ramos ou troncos consumidos, entre outras características, em inter‑relação
com determinados contextos arqueológicos (dimensões dos buracos de poste, por exemplo),
proporcionaram hipóteses relacionadas com a cadeia técnica‑operativa
dos recursos florestais.
A caracterização dos recursos usados em cada um dos casos de estudo permitiu, igualmente, colocar
hipóteses sobre o território de vivência, de circulação e de exploração de cada comunidade.Fundação para a Ciência e Tecnologi
Smartphone-enabled 3D printing of medicines
3D printing is a manufacturing technique that is transforming numerous industrial sectors, particularly where it is key tool in the development and fabrication of medicinees that are personalised to the individual needs of patients. Most 3D printers are relatively large, require trained operators and must be located in a pharmaceutical setting to manufacture dosage forms. In order to realise fully the potential of point-of-care manufacturing of medicines, portable printers that are easy to operate are required. Here, we report the development of a 3D printer that operates using a mobile smartphone. The printer, operating on stereolithographic principles, uses the light from the smartphone’s screen to photopolymerise liquid resins and create solid structures. The shape of the printed dosage form is determined using a custom app on the smartphone. Warfarin-loaded Printlets (3D printed tablets) of various sizes and patient-centred shapes (caplet, triangle, diamond, square, pentagon, torus, and gyroid lattices) were successfully printed to a high resolution and with excellent dimensional precision using different photosensitive resins. The drug was present in an amorphous form, and the Printlets displayed sustained release characterises. The promising proof-of-concept results support the future potential of this compact, user-friendly and interconnected smartphone-based system for point-of-care manufacturing of personalised medications
BAC libraries construction from the ancestral diploid genomes of the allotetraploid cultivated peanut.
FIDEL-a retrovirus-like retrotransposon and its distinct evolutionary histories in the A- and B-genome components of cultivated peanut.
Ab initio model potential study of the optical absorption spectrum of Mn(2+)-doped CaF2
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