1,850 research outputs found
Water calcium concentration modifies whole-body calcium uptake in sea bream larvae during short-term adaptation to altered salinities
Whole-body calcium uptake was studied in gilthead sea bream larvae (9–83·mg) in response to changing environmental salinity and [Ca2+]. Calcium uptake increased with increased fish size and salinity. Fish
exposed to calcium-enriched, diluted seawater showed increased calcium uptake compared with fish in diluted seawater alone. Calcium uptake was unchanged in Na+-
enriched, diluted seawater. Overall, [Ca2+], and not salinity/osmolarity per se, appears to be the main factor contributing to calcium uptake. By contrast, drinking was
reduced by a decrease in salinity/osmolarity but was little affected by external [Ca2+]. Calculations of the maximum contribution from drinking-associated calcium uptake
showed that it became almost insignificant (less than 10%) through a strong decrease in drinking rate at low salinities (0–8‰). Diluted seawater enriched in calcium to the
concentration present in full-strength seawater (i.e. constant calcium, decreasing salinity) restored intestinal calcium uptake to normal. Extra-intestinal calcium uptake
also benefited from calcium addition but to a lesser extent
A decision support system framework to track consumer sentiments in social media
With the evolution of web 2.0 and social networks, customers and companies’ online interaction is growing at a fast pace, containing valuable insights about consumers’ expectations that should be monitored and explored in a day-to-day basis. However, such information is highly unstructured and difficult to analyze. There is an urgent need to set up transparent methods and processes to integrate such information in the tourism industry technological infrastructure, especially for small firms that are unable to pay for expensive services to monitor their online reputation. The current paper uses a text mining and sentimental analysis technique to structure online reviews and present them on a decision support system with two different dashboards to assist in decision-making. Such system may help managers develop new insights and strategies aligned with consumers’ expectations in a much more flexible and sustainable pace.info:eu-repo/semantics/acceptedVersio
Autonomic emotional responses to food: private label brands versus national brands
Private label brands (PLB) have been increasing both perceived quality and consumer acceptance in the last decades, which has compelled national brands (NBs) to invest in maintaining consumer confidence and preference. Recent economic crisis led consumers to become more price sensitive and more worried about cutting on daily needs, such as food consumption. However, taste is still one of the most important factor of decision for consumers regarding food products. Despite such importance of taste in decision-making, most research on consumer senses still relies on traditional methods of surveying consumers, which are unable to measure the consumers' autonomic emotional reactions. The current paper uses a psychophysiological method to measure emotional arousal–electrodermal activity (EDA) and a self-assessment manikin to measure pleasure. Emotions are then tested to assess their influence on perceived quality and willingness to buy (WTB). Findings show that NB are still perceived by consumers as superior, but consumers' WTB is not higher for NB. These results show that consumers' decisions are not always in favor of the product which is perceived to have a better quality which suggests that the “quality gap” is fading and the “branding gap” is gaining momentum.info:eu-repo/semantics/acceptedVersio
Dark matter from cosmic defects on galactic scales?
We discuss the possible dynamical role of extended cosmic defects on galactic
scales, specifically focusing on the possibility that they may provide the dark
matter suggested by the classical problem of galactic rotation curves. We
emphasize that the more standard defects (such as Goto-Nambu strings) are
unsuitable for this task, but show that more general models (such as transonic
wiggly strings) could in principle have a better chance. In any case, we show
that observational data severely restricts any such scenarios.Comment: Submitted to Phys. Rev. D (Brief Reports). v2: Reference added and
some typos corrected, matches published versio
Expressão de genes de resistência em resposta à infecção por nematóides.
A identificação de genes relacionados com a resistência de plantas a pragas e doenças é de grande importância para o entendimento dos mecanismos de defesa envolvidos durante o ataque de patógenos. Atualmente, vários desses genes, identificados em diferentes espécies vegetais, já foram caracterizados ao nível molecular e suas seqüências estão disponíveis em Bancos de Dados. Atualmente, com a conclusão do sequenciamento do Genoma Café, homólogos de genes de defesa tiveram suas seqüências estabelecidas. No entanto, estudos de genômica funcional são necessários para que o papel destes genes no mecanismo de resistência aos patógenos do café seja conhecido. Este trabalho tem como objetivo inicial caracterizar os mecanismos de defesa em café, através da identificação e avaliação da expressão de genes relacionados com a resistência a nematóides. Foram realizadas buscas de seqüências homólogas a genes de defesa no Banco de Dados do Genoma Café através do programa BLAST e foram identificados genes pertencentes a 12 categorias de genes de defesa. Em experimentos de infecção controlada, raízes de cafeeiros suscetíveis e resistentes foram infectadas pelo nematóide Meloidogyne exigua. Amostras de RNA extraído destas raízes serviram como molde para amplificação de transcritos correspondentes a 6 genes de resistência. Os resultados mostram que os genes avaliados neste estudo apresentam uma expressão basal em raízes infectadas pelo nematóide, sugerindo que a ativação da resposta de defesa é controlada por outras famílias de genes não testadas neste estudo
Understanding the role of visual attention on wines’ purchase intention: an eye-tracking study
Purpose: Wine bottles compete for consumers’ attention in the shelf during the decisive moment of choice. This study aims to explore the role that visual attention to wine labels has on the purchase decision and the mediating role of quality perceptions and desire on such purchase behaviours. Wine awards and consumption situation are used as moderators. Design/methodology/approach: The study was conducted in Portugal and 36 individuals participated in a 2 × 2 within subjects design (awarded/not awarded × self-consumption/social-consumption). For each scenario, individuals’ attention, perceptions of quality, desire and purchase intentions were recorded. Findings: Data from eye-tracking shows that, during the purchase process, the amount of attention given to a bottle is determinant of individuals’ purchase intentions, a relationship that increases in significance for bottles with awards and for when consumers are buying wine for a consumption situation involving a social environment. In addition, both quality perceptions and desire are confirmed to positively influence wines’ purchase intentions. Originality/value: By using an eye monitoring method, this paper brings new insights into the wine industry by highlighting the impact that wines’ labels and different consumption situations have on individuals’ attention and purchase intention. Wine producers and retailers may benefit from the insights provided by the current study to refine their communication strategies by either highlighting product characteristics and pictorial elements, as it is the case of the awards, or communicating about their products for different consumption situations.info:eu-repo/semantics/acceptedVersio
Evaluation of three iterative algorithms for phase modulation regarding their application in concentrating light inside biological tissues for laser induced photothermal therapy
Grant No. UIDB/00645/2020The focusing of light through turbid media like biological tissues is strongly hindered by the scattering of light which limits its safe practice and application in medicine. In order to control this phenomenon, we shaped the incident wavefront using three algorithms including a four-element division algorithm, a partitioning algorithm, and simulated annealing to control, iteratively, a spatial light modulator (SLM). We have tested two different convergence criteria to achieve a focal point inside a turbid environment, made up of a mixture of agar and milk, set to mimic a specific depth of human skin, and provide comparison results. A camera and a lens are used to visualize the focal area and give feedback information to the algorithms. A discussion on the use of these algorithms and convergence criteria is presented, being focused on its convergence time and performance. Depending on the algorithm and operational parameters, improvements of 29% to 46% of the irradiance in the region of interest were accomplished.publishersversionpublishe
Definição de uma metodologia para modelagem de agentes inteligentes difusos a partir da técnica de mapas mentais : um estudo de caso baseado na percepção e comportamento de usuários da praia Brava, SC – Brasil
Copyright © 2005 OLAMA partir da premissa de que os conhecimentos da percepção e do comportamento humanos são importantes para o entendimento de seus valores, e que estes podem influenciar no uso e ocupação do espaço, este artigo considera crucial ao processo de gestão ambiental a compreensão destes elementos. A pesquisa apresentada é de caráter exploratório, qualitativo e associa a investigação em cognição ambiental com inteligência artificial através do empreendimento da técnica de mapa mental para caracterização do perfil de grupos de usuários da praia Brava, Itajaí – SC, Brasil, a partir da percepção e comportamento de cada indivíduo frente a atributos espaciais do meio. Os perfis obtidos por este tipo de metodologia são testados num modelo de simulação baseada em agentes inteligentes difusos, uma técnica de inteligência artificial bastante recente. O uso da ferramenta de simulação para a gestão ambiental em áreas costeiras, em particular em praias, é uma importante forma de entender o impacto humano através da previsão de situações e medidas que visam o gerenciamento mais adequado do lugar.ABSTRACT: Understand people’s values and spatial behavior is important toward a successful environmental planning and management. This paper merge environmental perception and spatial behavior with simulation through the employment of a new simulation paradigm called intelligent fuzzy agent-based model. In this research, sketch maps and questionnaires were apply to study coastal zones user group’s perceptions and spatial behavior in order to provide information for modelling reasons. It was selected as study case the Praia Brava, Itajaí – SC, Brazil due to its diverse environment. As conclusion was proven that the methodology is an excellent method to categorize user’s perception and spatial behavior for computational codification
Caracterização de genes expressos durante o crescimento e maturação de frutos de café.
O objetivo do estudo foi caracterizar funcionalmente genes-chave expressos durante o crescimento e a maturação de frutos de cultivares de Coffea arabica L, pois a planta apresenta várias floradas, fato que resulta na maturação desigual de frutos, inclusive na mesma florada. Para o estudo foram utilizadas frutos em desenvolvimento das cultivares: Mundo Novo IAC 388-17, Catuaí Vermelho IAC 144, Icatu Vermelho IAC 4045, Obatã IAC 1669-20 e Icatu Precoce IAC 3282. Os genes escolhidos para análise foram: o fator de transcrição Leafy Cotyledon (LEC1) e as enzimas álcool acyl transferase e ácido 1-carboxílico 1-aminociclopropano (ACC) oxidase, os quais estão relacionados com os processos de desenvolvimento do embrião, composição química da semente e maturação do fruto, respectivamente. A expressão dos genes foi avaliada através da metodologia de RT-PCR, utilizando RNA total extraído dos frutos. Os resultados apresentados evidenciam que o padrão de expressão dos genes ACC oxidase, LEC1 e álcool acyl transferase são compatíveis com o esperado em frutos climatéricos e, as variações na expressão dos genes observada entre as cultivares sugerem que a composição química e a maturação dos frutos podem diferir ao longo do desenvolvimento dos frutos
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