E-commerce and Business Case of a US E-commerce firm

What do we know as E-commerce and E-Business? Unique features of E-commerce. Types of E-commerce. History and feature of E-commerce. Why does E-commerce develop better in some places than in others? What make a current E-commerce success? Introduction of the US E-commerce firm studied. Bussiness case (customer, product, company and competition). Conclusions.Outgoin

Degradación acelerada de morteros en medios agresivos artificiales de origen agropecuario

El presente trabajo pretende profundizar en el conocimiento de los mecanismos de degradación que se producen en la microestructura de la fase sólida de materiales empleados en la construcción de estructuras para uso agropecuario. El estudio se ha desarrollado con probetas de mortero de cemento CEM IV/B-V 32,5N sometidas a ensayos de degradación acelerada en medios agresivos artificiales. Las probetas se han sumergido en diferentes disoluciones, que contienen ácidos orgánicos con distinto pH. Las muestras se han caracterizado antes, durante y después del ensayo desde el punto de vista mecánico y microestructural. Los resultados obtenidos nos permiten identificar la agresividad que se desarrollaba en cada uno de los procesos de degradación en función del pH del medio y la composición del mismo, todo ello a fin de poder establecer el comportamiento en servicio del material

Exact soliton solutions of the one-dimensional complex Swift-Hohenberg equation

Using Painlev\'e analysis, the Hirota multi-linear method and a direct ansatz technique, we study analytic solutions of the (1+1)-dimensional complex cubic and quintic Swift-Hohenberg equations. We consider both standard and generalized versions of these equations. We have found that a number of exact solutions exist to each of these equations, provided that the coefficients are constrained by certain relations. The set of solutions include particular types of solitary wave solutions, hole (dark soliton) solutions and periodic solutions in terms of elliptic Jacobi functions and the Weierstrass $\wp$ function. Although these solutions represent only a small subset of the large variety of possible solutions admitted by the complex cubic and quintic Swift-Hohenberg equations, those presented here are the first examples of exact analytic solutions found thus far.Comment: 32 pages, no figures, elsart.cl

Intra-crustal recycling and crustal-mantle interactions in

In situ O-isotope compositions of detrital, inherited and melt-precipitated zircons with Neoproterozoic to Ordovician ages are presented to assess the crustal evolution of the North Gondwana margin. Different groups of pre-Mesozoic rocks from SW Iberia were targeted: i) Ediacaran paragneisses and meta-greywakes of the Ossa-Morena Zone – the Serie Negra Group deposited at ~ 560 Ma in a Cadomian magmatic arc setting (Pereira et al., 2008); ii) Early to Middle Cambrian orthogneisses and volcaniclastic rocks of the Ossa-Morena Zone – Evora Massif igneous complexes related to ensialic rifting at ~ 530–500 Ma (Pereira et al., 2008, Chichorro et al., 2008); iii) Late Cambrian to Early Ordovician volcaniclastic rocks and granites of the Ossa-Morena–Central Iberian transition zone – the Urra Formation and Portalegre granite formed at ~ 495– 488 Ma in a extensional setting (Solá et al., 2008); iv) Carboniferous granitoids (Nisa and Arraiolos granites) containing inherited zircons with Cambrian to Ordovician ages (Solá, this volume). A compilation the results for the period ~ 3.4 Ga to ~ 450 Ma reveals that: a) Archean zircons show little variation in d18O, with most values lying between 4.7 and 7.5‰, (average 6.2‰) comparable with usual d18O of zircons from Archean elsewhere (e.g., Valley et al., 2005); b) the range of d18O in Paleoproterozoic grains increases between 2.1 and 1.8 Ga with d18O >7.5‰, indicating increasing supracrustal recycling, but at ~ 1.8 Ga the d18O has mantle-like values (<5.1‰), documenting a crustal growth episode at this time; c) rare Mesoproterozoic grains have mildly evolved d18O values in the range 5.6–7.1‰); d) Tonian grains have low d18O values (4.2–5.6‰) typical of mantle-derived juvenile magmas but also higher values of 9.9‰ suggesting intra-crustal recycling; e) Cryogenian–Ordovician zircons show more variable and higher d18O values (~4 to >10‰), indicating great diversity and mixing of sources through intra-crustal recycling and crust–mantle interactions; f) some d18O values near to or below mantle composition (5.3 ± 0.3‰) were recorded at ~ 590 Ma (Ediacaran) suggesting input of mantle material into the crust; g) a decrease in variance of d18O occurs from 575 Ma to the Ediacaran/Cambrian boundary, suggesting a relative decrease in the magmatic contribution of surface-derived material; h) in Cambrian times, the average d18O is higher in the 536–520Ma interval (7.0‰) than in the 520–488 interval (6.2‰), which can be taken as a signal of gradual opening of the system to mantle-derived, mafic, rift-related igneous complexes; i) higher values of d18O (>7.5 ‰) recorded at ~ 623–574 Ma and 490–470Ma mark periods of pronounced increase in crustal recycling

Rift-related volcanism predating the birth of the Rheic Ocean

Two very different periods of magma emplacement in the crust of the Ossa-Morena zone (early and main events) in SW Iberia have been previously interpreted to record a Cambrian/Early Ordovician rifting event that is thought to have culminated in the opening of the Rheic Ocean during the Early Ordovician. New stratigraphic, petrographic, geochemical and Sm–Nd isotope data from Cambrian volcanic rocks included in six key low-grade sections in both Portugal and Spain considerably improve our understanding of these events. These data: (1) confirm the existence of two rift-related magmatic events in the Cambrian of the Ossa-Morena zone, (2) demonstrate that the early rift-related event was associated with migmatite and core-complex formation in the mid-upper crust and is represented by felsic peraluminous rocks, the parent magmas of which were derived mainly from crustal sources, and (3) show the main rift-related event to be represented by a bimodal association of felsic and mafic rocks with minor amounts of intermediate rocks. Some of the mafic rocks show N-MORB affinity, whereas others have OIB or E-MORB affinities, suggesting different heterogeneous mantle sources (depleted and enriched, asthenospheric and lithospheric, plume-like and non-plume-like). The acid and intermediate rocks appear to represent hybrid mixtures of crust and mantle-derived magmas. This new data supports the hypothesis that the onset of rifting was associated with a process of oblique ridgetrench collision. We interpret the significant differences between the early and main events as reflecting the evolution froma wide rift stagewith passive extensionmainly accommodated by lower-crust flowin a high heatflow setting, to a narrow rift stage with active extension characterized by extension rates that outpaced thermal diffusion rates

Prevención de La Hepatitis B en los trabajadores de salud en la visión de los estudiantes de enfermería

O estudo objetivou analisar as ações do enfermeiro na prevenção da Hepatite B em trabalhadores de saúde. Pesquisa de abordagem qualitativa e descritiva, cujos entrevistados foram dez acadêmicos de Enfermagem. A análise temática revelou que, na visão dos colaboradores, a educação, com ênfase na utilização dos Equipamentos de Proteção Individual, e a vacinação são as principais ações dos enfermeiros na prevenção da Hepatite B. Estas atividades envolvem o reconhecimento e a participação dos trabalhadores, bem como o apoio institucional. Como conclusão a pesquisa reforça a relevância de maior conhecimento sobre a temática na formação dos profissionais de enfermagem, tendo como foco a promoção da saúde, a prevenção e a capacitação para a realização da vigilância epidemiológica para o controle da doença. Nesse sentido, as ações realizadas pelo enfermeiro visam contribuir diretamente na melhoria da qualidade de vida do trabalhador.Abstract: The study aimed to analyze the actions of the nurse in the prevention of Hepatitis B on health workers. The qualitative and descriptive search of approach, whose interviewed were ten Nursing students. Thematic analysis revealed that, in the view of collaborators, education, with emphasis on the use of Personal Protective Equipment and vaccination are the main actions of nurses in the prevention of Hepatitis B. These activities involve the recognition and worker participation as well as institutional support. As a conclusion the research strengthens the importance of better understanding on the subject in the training of nursing professionals focusing on health promotion, prevention and training that makes possible the realization of epidemiological surveillance for disease control. Accordingly, the actions taken by nurses aim to contribute directly in improving the quality of workers life.Resumen : Este estudio tiene como objetivo analizar las acciones del enfermero en la prevención de la Hepatitis B en trabajadores de salud. Investigación de abordaje cualitativa y descriptiva, cuyos entrevistados fueron diez académicos de Enfermería. El análisis temático mostró en la visión de los colaboradores, la educación, con énfasis en la utilización de los Equipamientos de Protección Individual y la vacunación son las principales acciones de los enfermeros en la prevención de la Hepatitis B. Estas actividades envuelven el reconocimiento y la participación de los trabajadores, así como el apoyo institucional. Como conclusión la investigación refuerza la relevancia de mayor conocimiento sobre la temática en la formación de los profesionales de enfermería, teniendo como foco la promoción de la salud, la prevención y la capacitación que posibilite la realización de la vigilancia epidemiológica para el control de la enfermedad. En ese sentido, las acciones realizadas por el enfermero tienden a contribuir directamente en la mejora de la calidad de vida del trabajador

Decoding negative affect personality trait from patterns of brain activation to threat stimuli

INTRODUCTION: Pattern recognition analysis (PRA) applied to functional magnetic resonance imaging (fMRI) has been used to decode cognitive processes and identify possible biomarkers for mental illness. In the present study, we investigated whether the positive affect (PA) or negative affect (NA) personality traits could be decoded from patterns of brain activation in response to a human threat using a healthy sample. METHODS: fMRI data from 34 volunteers (15 women) were acquired during a simple motor task while the volunteers viewed a set of threat stimuli that were directed either toward them or away from them and matched neutral pictures. For each participant, contrast images from a General Linear Model (GLM) between the threat versus neutral stimuli defined the spatial patterns used as input to the regression model. We applied a multiple kernel learning (MKL) regression combining information from different brain regions hierarchically in a whole brain model to decode the NA and PA from patterns of brain activation in response to threat stimuli. RESULTS: The MKL model was able to decode NA but not PA from the contrast images between threat stimuli directed away versus neutral with a significance above chance. The correlation and the mean squared error (MSE) between predicted and actual NA were 0.52 (p-value=0.01) and 24.43 (p-value=0.01), respectively. The MKL pattern regression model identified a network with 37 regions that contributed to the predictions. Some of the regions were related to perception (e.g., occipital and temporal regions) while others were related to emotional evaluation (e.g., caudate and prefrontal regions). CONCLUSION: These results suggest that there was an interaction between the individuals' NA and the brain response to the threat stimuli directed away, which enabled the MKL model to decode NA from the brain patterns. To our knowledge, this is the first evidence that PRA can be used to decode a personality trait from patterns of brain activation during emotional contexts

Comparación de la eficacia y seguridad diagnóstica entre el estudio isotópico hepatobiliar y la ecografía en la colecistitis aguda

Hemos estudiado en 67 pacientes con el diagnóstico de colecistitis aguda (CA) confirmado mediante intervención quirúrgica precoz, la sensibilidad diagnóstica del estudio isotópico con HIDA comparándola con la de la ecografía. El estudio se llevó a cabo de forma retrospectiva. La sensibilidad del estudio isotópico (97%) ha sido claramente superior a la de la ecografía (82%), aunque esta última ofrece ventajas en cuanto a la rapidez y economía de valor indudable. Asimismo hemos intentado establecer la seguridad de ambas técnicas en el diagnóstico de la coledocolitiasis asociada a la CA, que en nuestro estudio ha mostrado una incidencia alta (26%), siendo mala para ambas técnicas; la sensibilidad en este caso para la ecografía ha sido del 50% mientras que para el HIDA ha sido del 12,5%. Por tanto creemos conveniente realizar como primer estudio diagnóstico para la confirmación de la sospecha clínica de CA una ecografía abdominal, reservando la escintigrafía para los casos, por otra parte numéricamente apreciables, en que persista la duda diagnóstica. Asimismo recomendamos la realización de colangiografía intraoperatoria debido a la deficiente fiabilidad que ambas exploraciones han demostrado en la detección de coledocolitiasis en los pacientes con C

The theoretical models in nursing services in vision of nurses of assistance : an exploratory study

Esta pesquisa tem como objeto de estudo a implementação dos modelos teóricos na Sistematização da Assistência de Enfermagem (SAE) na visão dos enfermeiros assistenciais. Tem por objetivo analisar os desafios faced by nurses to implement the theoretical models in enfrentados pelos enfermeiros para a implementação dos modelos teóricos nos serviços de enfermagem. A abordagem metodológica é de natureza qualitativa, descritiva e exploratória. Os sujeitos do estudo foram health institutions in the city of Rio de Janeiro, Brazil. Os resultados revelaram que mesmo os profissionais tendo conhecimento sobre a importância da escolha dos modelos teóricos para a implantação da SAE, esse processo ainda se encontra deficitário em nosso país em virtude de diversos fatores de ordem pessoal, profissional e institucional. Observa-se a necessidade de haver maior interesse por parte do enfermeiro e das instituições de saúde no sentido de investir no aprimoramento e na capacitação de pessoal para a implementação efetiva da SAE, visando à melhoria da qualidade dos serviços oferecidos à população, maior reconhecimento e valorização do profissional de enfermagem.Abstract: This research aims to study the implementation of theoretical models in the Nursing Care System (NCS) in the viewpoint of nurses. It aims to analyze the challenges faced by nurses to implement the theoretical models in nursing services. The methodological approach is qualitative, descriptive and exploratory. The study subjects consisted of 11 nurses working in care, in several health institutions in the city of Rio de Janeiro, Brazil. The results revealed that even when professionals know about the importance of the choice of theoretical models for the implementation of the NCS, this process is still deficient in our country, due to various personal, professional and institutional factors. There is a need for greater interest on the part of nurses and health institutions, to invest in upgrading and training of personnel for the effective implementation of the NCS in order to improve the quality of services offered to the population and greater recognition and enhancement of the nursing professional

Antiophidian properties of plant extracts against Lachesis muta venom

Snakebites comprise a serious health problem in several countries due to their global incidence, which exceeds 2.5 million per year, and the elevated number of victim fatalities. To counteract envenomations, antivenoms have been used regularly for more than a century. Apart from side effects including anaphylactic reactions, antivenoms are not able to efficiently neutralize local tissue damage, which contributes to increasing the severity and morbidity observed in patients. This fact, in turn, may be responsible for economic hardship, particularly in rural populations of developing countries. In the present work, we evaluated the antiophidian properties of 12 Brazilian plant extracts against the hemolytic, coagulant, hemorrhagic and proteolytic effects of Lachesis muta venom. Taken together, our data revealed that most of these aqueous products were capable of inhibiting those activities at different levels, except for Sapindus saponaria extract. In contrast, Stryphnodendron barbatiman extract completely neutralized all the analyzed biological activities. Thus, we may conclude that Brazilian flora may also be useful against L. muta accidents.(FAPERJ) Fundacao de Amparo a Pesquisa do Estado do Rio de JaneiroFAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)International Foundation for Science (IFS, Sweden