979 research outputs found
Origin of anomalously long interatomic distances in suspended gold chains
The discovery of long bonds in gold atom chains has represented a challenge
for physical interpretation. In fact, interatomic distances frequently attain
3.0-3.6 A values and, distances as large as 5.0 A may be seldom observed. Here,
we studied gold chains by transmission electron microscopy and performed
theoretical calculations using cluster ab initio density functional formalism.
We show that the insertion of two carbon atoms is required to account for the
longest bonds, while distances above 3 A may be due to a mixture of clean and
one C atom contaminated bonds.Comment: 4 pages, 4 Postscript figures, to be published in Physical Review
Letter
Rebranding da aplicação para surfistas"Qual a tua onda?", do Instituto Hidrográfico
Trabalho de projeto submetido como requisito parcial para obtenção do grau de mestre em publicidade e marketing.Os smartphones e as aplicações são uma arma de comunicação muito forte. A sua utilização tem vindo a crescer nos últimos anos, sendo uma das tecnologias mais utilizadas pelos consumidores, eliminando as barreiras de tempo de espaço. Neste contexto, as marcas têm vindo a trabalhar de forma a estarem presentes neste novo canal de comunicação, de uma forma mais leve e emocional. Com base neste contexto social e económico, o Instituto Hidrográfico criou uma aplicação chamada “Qual tua onda?”, de forma a ir ao encontro dos possíveis utilizadores dos seus dados, os surfistas. Disponibilizando assim, a informação necessária para a prática do surf. Apesar de ter sido uma boa iniciativa, reparamos que havia algumas inconformidades com esta aplicação. O nome, a comunicação e até a informação que disponibilizavam não era coerente com o objetivo e não ia ao encontro com as necessidades e filosofias dos surfistas. Desta forma, após percebermos quais eram as debilidades da antiga aplicação, através de uma investigação de suporte privilegiando o método quantitativo, operacionalizado por via da aplicação de um inquérito por questionário a 121 pessoas e após a uma extensa avaliação ao mercado das aplicações do surf, percebemos que era importante fazer um rebranding à aplicação do Instituto Hidrográfico, colocando novas características, funcionalidades e a essência do surf nesta nova aplicação. Nascendo assim, a “GimmeSwell”.Smartphones and applications are a very powerful communication weapon. The apps have been growing recently and now are one of the technologies most used by consumers, eliminating the barriers of space and time. In this context, brands have been working to be present in this new channel. Based on this social and economic context, the InstitutoHidrográfico created an application called "Qual a tuaonda?" (What is your way?).In order to reachnew users of theirforecast data, the surfers. Providing, the necessary information for the practice of surfing. Although it was a good initiative, but we noticed that there were some nonconformities with this application. The name, the communication and even the information they provided was not consistent with their initial objectives. In this way, after realizing what are wrong with the app “Qual a tuaonda?”, and through an investigation with a quantitative method by questionnaire with a survey to 121 people and after an extensive evaluation to the market of surf applications, we realized that it was important to rebranding the application of the InstitutoHidrográfico, putting on new characteristics, functionalities and the essence of surfing in this new application. Born this way, the app "Gimme Swell".N/
Modelagem de uma Aplicação Web a partir de um Framework de Agenda de Tarefas
Este artigo apresenta a modelagem de uma aplicação Web a partir de um framework de agenda de tarefas para gerenciadores de processos. O framework foi desenvolvido com base no método Catalysis e foi validado por meio de um protótipo implementado na linguagem Java. Além da modelagem Web, é apresentado uma arquitetura componentizada do framework e a modelagem de banco de dados gerada a partir do projeto. O padrão de modelagem utilizada foi a UML com a ferramenta CASE IBM Rational Rose. Este trabalho contribui para definição e construção de arquiteturas para desenvolvimento baseado em componentes desde a fase de requisitos até a geraçãodo banco de dados e codificação
Combining experiences of race gaming and natural driving affects gaze location strategy in simulated context
The influence of anxiety on visual entropy of experienced drivers
This study tested the use of entropy to identify changes on behavior of drivers under pressure. Sixteen experienced drivers drove in a simulator wearing a head-mounted eye tracker under low- and high-anxiety conditions. Anxiety was induced by manipulating some psychological factors such as peer-pressure. Fixations transitions between AOIs (lane, speedometer and mirrors) were calculated through first-order transition matrix, transformed to Markov probability matrix and adjusted into the entropy equation. Drivers showed greater state-anxiety scores and higher mean heart rates following manipulation. Under anxiety, drivers showed higher visual entropy, indicating a more random scanning. The randomness implies into a poorer acquisition of information and may indicate an impaired top-down control of attention provoked by anxiety
Detecção de contaminação de solo por vinhaça através de análise de dados de eletrorresistividade
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The vinasse, awaste produced in the proportion of 13 liters for each liter of alcohol. It has a high potential of polluting groundwater and superficial water resources, changes the soil behaviour and can also develop sanilization problems. This work aims to evaluate the efficiency of the DC-resistivity method in detecting and mapping anomalies caused by inappropriate disposal of vinasse in an inactive infiltration tank located at Sepé-Tiarajú settlement of landless agricultural laborers in the Ribeirão Preto region. Besides, as secondary goals, this work aims to characterize the type of anomaly residue as well as to diagnose its influence inside and outside of the limits of the tank. Eleven electrical resistivity tomography profiles were carried out with the dipole-dipole array, 10m of dipoles length and 5 leveis of investigation The geophysical survey enabled us to conclude that the DC-resistivity method is appropriate for mapping the contamination plume caused by intense vinasse disposal and its influence. It enabled also to conclude that the contamination exceeds the tank limits. The vinasse influence can be characterized by low resistivity values between 10 Ohm.m and 90 Ohm.m and its behavior can be compared with the one of the chorume, which is also conductive.A vinhaça, resíduo gerado na proporção de 13 litros para cada litro de álcool produzido, possui um alto potencial poluidor dos recursos hídricos subterrãneos e superficiais, causa alterações no comportamento do solo e pode gerar problemas de salinização. Este trabalho objetiva avaliar a eficiência do método da eletrorresistividade para a detecção e mapeamento das anomalias causadas pela disposição inadequada de grandes quantidades de vinhaça em um antigo tanque de infiltração localizado no Assentamento Sepé-Tiarajú, Região de Ribeirão Preto -SP. O trabalho objetiva também caracterizar o tipo de anomalia inerente ao resíduo no local estudado e diagnosticar sua influência dentro e fora dos limites do tanque. Foram executados onze perfis de tomografia elétrica, arranjo dipolo-dipolo radial e espaçamento entre eletrodos de 10 metros e 5 níveis de investigação. Os ensaios geofísicos mostraram que o método da eletrorresistividade é apropriado para mapear as anomalias decorrentes da disposição de grandes quantidades de vinhaça no solo, apontar suas áreas de influência e concluir que a contaminação extrapola os limites do tanque. A influência da vinhaça pode ser caracterizada por baixos valores de resistividade entre 10 Ohm.m e90 Ohm.m, podendo o seu comportamento ser comparado ao do chorume, que também é bastante condutivo.264481492Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPq_Brasi
Validation of epidemiological tools for eczema diagnosis in brazilian children: the isaac's and uk working party's criteria
BACKGROUND: Instruments for field diagnosis of eczema are increasingly used, and it is essential to understand specific limitations to make best use of their strengths. Our objective was to assess the validity of ISAAC and UK Working Party criteria for field diagnosis of eczema in children. METHODS: We performed a cohort study in urban Brazil. Parents/guardians of 1,419 children answered ISAAC phase II questionnaire. Children were examined for skin lesions (UKWP protocol). Two dermatologists examined most cases of eczema (according to ISAAC or UKWP), and a sample without eczema. RESULTS: Agreement between repeat questionnaires on the filter question was poor (kappa = 0.4). Agreement between the 2 dermatologists was fair (kappa = 0.6). False positive reports included scabies in 39% of ISAAC cases and 33% of UKWP cases. Sensitivity and PPV were low (ISAAC: 37.1% and 16.1%; UKWP: 28.6% and 23.8%). Specificity and NPV were high (ISAAC: 90.0% and 96.6%; UKWP: 95.3% and 96.2%). One-year prevalence of eczema was 11.3% (ISAAC), 5.9% (UKWP) and 4.9% (adjusted dermatologist diagnosis). Point prevalence of scabies (alone or not) was 43%, 33% and 18%, in eczemas according to ISAAC, to UKWP and to dermatologists. The reasons why children with eczema were not identified by ISAAC or UKWP were wrongly denying dry skin, itchy rash or personal history of atopic diseases. A limitation is that questionnaire was already validated in Brazil, but not field tested in this specific setting. CONCLUSIONS: Studies using UKWP or ISAAC criteria should include a validation arm, to contribute to the understanding of potential limitations of their use in different contexts and to explore solutions. We list specific recommendations
Chronic virus infections supress atopy but not asthma in a set of children from a large latin american city: a cross-section study
<p>Abstract</p> <p>Background</p> <p>The prevalence of allergic diseases has increased over recent decades in affluent countries, but remains low in rural populations and some non-affluent countries. An explanation for these trends is that increased exposure to infections may provide protection against the development of allergy. In this work we investigated the association between exposure to viral infections in children living in urban Brazil and the prevalence of atopy and asthma.</p> <p>Methods</p> <p>School age children living in poor neighborhoods in the city of Salvador were studied. Data on asthma symptoms and relevant risk factors were obtained by questionnaire. Skin prick tests (SPTs) were performed to seven aeroallergens, and specific IgE was measured to four of these. Viral infections were determined by the presence of specific IgG in serum to Herpes simplex (HSV), Herpes zoster (HZV), Epstein-Barr (EBV), and Hepatitis A (HAV) viruses.</p> <p>Results</p> <p>A total of 644 (49.7%) children had at least one allergen-specific IgE> 0.35 kU/L and 489 (37.7%) had specific IgE> 0.70 kU/L. A total of 391 (30.2%) children were skin test positive (SPT+), and 295 (22.8%) children were asthmatic. The seroprevalence of viral infections was 88.9% for EBV, 55.4% for HSV, 45.5% for VZV and 17.5% for HAV. Negative associations were observed between SPT+ and HSV (OR = 0.64, CI = 0.51, 0.82) and EBV (OR = 0.63, CI = 0.44, 0.89) infections, but no associations were seen between viral infections and the presence of allergen-specific IgE or asthma.</p> <p>Conclusion</p> <p>These data do not support previous data showing a protective effect of HAV against atopy, but did show inverse associations between SPT+ (but not specific IgE+) and infections with HSV and EBV. These findings suggest that different viral infections may protect against SPT+ in different settings and may indicate an immunoregulatory role of such infections on immediate hypersensitivity responses. The data provide no support for a protective effect of viral infections against asthma in this population.</p
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