2,308 research outputs found
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
Central Algarve tufa platforms, Southern Portugal. Geomorphological characterization and genesis.
Modern and fossil carbonate tufa outcrops exist in the Algarve (S Portugal), where climate is Mediterranean and
all modern incrusting springs are intermittent and fed by Jurassic aquifers. The major Pleistocene tufa on the
Algibre flexure southern slopes are in the Cadouço, São Lourenço and Rio Seco streams basins. There were
identified fluvial barrier tufas and low energy fluvial tufas.
The Algarve has three main geomorphological domains: the Paleozoic flysch mountains, the Meso-cenozoic
karst hills and the littoral Plio-Pleistocene detrital platform.Located in the Eurasian-Nubian plates boundary, the
whole system have been deformed by distensive and compressive tectonics, which give rise to a complex
groundwater system. Neotectonical activity has been reported in many works.
Feio (1952) identified Pliocene and Quaternary marine platforms up to 160 m a.s.l., but also mature levels at 200
m along with other plain surfaces.
The largest tufa platforms lie in unconformity with the currentdrainage system, where outcrops are dominated by
low gradient facies, v. g. detrital bedded lime muds. Machados platform is dominated by bryophytes and other
rapid flow facies, and cemented riverbed upstream. These outcrops lie down on larger areas in Loulé and Lagos
e Relva, at altitudes between 160-200 and 120-150 respectively.
Environmentally conformal tufas occupy some sectors of the modern Cadouço, Rio Seco and São Lourenço
streams. Modern tufa range from spring dominated mounds in Lagos eRelva and barrier and low gradient fluvial
dominated tufas (v. g. São Lourenço and Loulé).
The ocean proximity enables the formation of eustatic platforms, which provided substratum for tufa
accumulations. Vertical movements, including salt tectonics, and lowstands promoted fluvial incision and later
tufa developments in modern streams.
Acknowledgments: Financed by the Fundação para a Ciência e Tecnologia PhD grant SFRH/BD/62323/2009
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
Ulcerative colitis: let's talk about extent
Ulcerative colitis (UC) is a chronic inflammatory disease in which clinical course varies substantially between patients.
The extent of the disease is usually pointed out as one of the factors
responsible for this variation. With this study, we pretended to evaluate the differences in natural history and pharmacological therapy
prescription between left-sided and extended UC
Respuestas emocionales-motivacionales de los locales frente a los extranjeros hacia la comida tradicional Y no tradicional
Purpose: The purpose of this paper was to study responses to traditional food of a country, focusing on emotion-motivational responses by locals and foreigners. Design/methodology/approach: Through an experimental design study, Portuguese and Foreign participants were exposed to both traditional and nontraditional food pictures of a country and asked to evaluate their emotional and motivational responses while physiological responses of electrodermal activity were continuously recorded. Predisposition factors of body dissatisfaction, food neophobia, and food involvement were also evaluated given their potential role in predicting the responses to the visualization of the food pictures. Findings: This study found that local traditional food received a higher positive evaluation than nontraditional food with locals evaluating it even higher than foreigners. Higher feelings of arousal and desire as well as willingness to try in response to traditional food were also found as well as higher feelings of pleasure by locals. However, interestingly, and contrary to expectations derived from previous literature, emotion-motivational responses were not significantly different between locals and foreigners. Originality/value: To the best of the authors’ knowledge, this research addressed an identified research gap in the literature, being the first one evaluating the autonomic responses of consumers to traditional food by exploring how local and foreign consumers respond to traditional food versus nontraditional food using psychophysiological measures of emotion.info:eu-repo/semantics/publishedVersio
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
La régulation des plateformes dans le secteur du transport de passagers au Portugal et en Espagne: Stratégies différentes, coalitions différentes
Digital Platform Work (DPW) is part of a new phase of capitalism, in which monopolistic digital platforms use algorithms to mediate labour supply and demand. As DPW grows, the share of atypical workers in the labour market increases and European Union states are pressed to regulate it, but the strategies adopted are different. This is the case with the regulation of DPW in the passenger transport sector approved by the governments of Portugal and Spain. This paper makes a comparative analysis of these case studies based on parliamentary debates and media reports. We argue that the centre-left parties which led the governments in both countries, adopted a distinct regulation strategy because they each have specific conceptions of solidarity.info:eu-repo/semantics/publishedVersio
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
Improving international attractiveness of higher education institutions based on text mining and sentiment analysis
Purpose: The increasing competition among higher education institutions (HEI) has led students to conduct a more in-depth analysis to choose where to study abroad. Since students are usually unable to visit each HEIs before making their decision, they are strongly influenced by what is written by former international students (IS) on the Internet. HEIs also benefit from such information online. This paper aims to provide an understanding of the drivers of HEIs success online. Design/methodology/approach: Due to the increasing amount of information published online, HEIs have to use automatic techniques to search for patterns instead of analyzing such information manually. The present paper uses text mining and sentiment analysis to study online reviews of IS about their HEIs. The paper studied 1938 reviews from 65 different business schools with AACSB accreditation.
Findings: Results show that HEIs may become more attractive online if they financially support students cost of living, provide courses in English, and promote an international environment.
Research limitations/implications
Despite the use of a major platform with a broad number of reviews from students around the world, other sources focused on other types of HEIs may have been used to reinforce the findings in the current paper.
Originality/value: The study pioneers the use of text mining and sentiment analysis to highlight topics and sentiments mentioned in online reviews by students attending HEIs, clarifying how such opinions are correlated with satisfaction. Using such information, HEIs’ managers may focus their efforts on promoting international attractiveness of their institutions.info:eu-repo/semantics/acceptedVersio
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