2,152 research outputs found

    Dataset for holiday rentals’ daily rate pricing in a cultural tourism destination

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    This data article describes a holiday rental dataset from a medium-size cultural city destination. Daily rate and variables related to location, size, amenities, rating, and seasonality are highlighted as the main features. The data was extracted from Booking.com, legal registration of the accommodation (RTA) and Google Maps, among other sources. This dataset contains data from 665 holiday rentals offered as entire flat (rent per room was discarded), with a total of 1623 cases and 28 variables considered. Regarding data extraction, RTA is ordered by registration number, which is taken and, through a Google search with the following structure: "apartment registration no. + Booking + Seville", the holiday rental profile in Booking.com is found. Then, it is verified that both the address of the accommodation and the registration number match in RTA and Booking.com, proceeding with data extraction to a Microsoft Excel's file. Google Maps is used to determine the minutes spent walking from the accommodation to the spot of maximum tourist interest of the city. A price index based on the average price per square meter of real estate per district is also incorporated to the dataset, as well as a visual appeal rating made by the authors of every holiday rental based on its Booking.com photos profile. Only cases with complete data were considered. A statistics summary of all variables of the data collected is presented. This dataset can be used to develop an estimation model of daily prices of stay in holiday rentals through predetermined variables. Econometrics methodologies applied to this dataset can also allow testing which variables included affecting the composition of holiday rentals' daily rates and which not, as well as determining their respective influence on daily rates.info:eu-repo/semantics/publishedVersio

    Interaction of H2_2S with H atoms on grain surfaces under molecular cloud conditions

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    Hydrogen sulfide (H2_2S) is thought to be efficiently formed on grain surfaces through the successive hydrogenation of S atoms. Its non-detection so far in astronomical observations of icy dust mantles thus indicates that effective destruction pathways must play a significant role in its interstellar abundance. While chemical desorption has been shown to remove H2_2S very efficiently from the ice, in line with H2_2S gas-phase detections, possible solid-state chemistry triggered by the related HS radical have been largely disregarded so far -- despite it being an essential intermediate in the H2_2S + H reaction scheme. We aim to thoroughly investigate the fate of H2_2S upon H-atom impact under molecular cloud conditions, providing a comprehensive analysis combined with detailed quantification of both the chemical desorption and ice chemistry that ensues. Experiments are performed in an ultrahigh vacuum chamber at temperatures between 10--16 K. The changes in the solid phase during H-atom bombardment are monitored in situ by means of reflection absorption infrared spectroscopy (RAIRS), and desorbed species are measured with a quadrupole mass spectrometer (QMS). We confirm the formation of H2_2S2_2 via reactions involving H2_2S + H, and quantify its formation cross section under the employed experimental conditions. Additionally, we directly assess the chemical desorption of H2_2S by measuring the gas-phase desorption signals with the QMS, providing unambiguous desorption cross sections. Chemical desorption of H2_2S2_2 was not observed. The relative decrease of H2_2S ices by chemical desorption changes from ~85% to ~74% between temperatures of 10 and 16 K, while the decrease as the result of H2_2S2_2 formation is enhanced from ~5% to ~26%, suggesting an increasingly relevant sulfur chemistry induced by HS radicals at warmer environments. The astronomical implications are further discussed.Comment: 11 pages, 9 Figures, 3 Tables. Accepted for publication in Astronomy and Astrophysic

    Caffeine Dose-Response Relationship and Behavioral Screening in Zebrafish

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    It has been centuries since humans consume coffee and get the benefits of this bean. Many researches worldwide continue to show healthful properties of coffee, while others suggest a number of side effects. In fact, anything consumed in excess may cause disturbance of the body functioning, whereas caffeine is a central nervous system stimulant that increases focus and improves performance, its high concentration can cause insomnia, dizziness, and vomiting. Thus, the question is: which coffee dose promotes benefits and prevents risks? To answer it, we used the zebrafish, a popular animal model that is at the vanguard of psychopharmacological research due to its unique combination of complexity and simplicity, translational relevance and applicability to high throughput behavioral drug screens. In the current study, we examine time-course and dose-dependent changes in zebrafish following exposure to caffeine. Our data show an inverted U-shaped path for the locomotor parameters and crescent path for the anxiety-like parameters. High doses are harmful to the individual, because the stimulating effect disappears and anxiogenic effects take place. We conclude that temporal analysis of zebrafish behavior is a sensitive method for the study of acute caffeine exposure–induced functional changes in the vertebrate brain

    Envolver os alunos de forma produtiva em aulas de ciências físicas: evidências para uma proposta de uma ferramenta para ajudar os professores

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    A qualidade das aprendizagens dos alunos nas aulas de Ciências Físicas pode melhorar se a mediação do professor atribuir um papel fundamental ao envolvimento produtivo dos alunos. A partir de narrações sobre a mediação do professor em contexto de sala de aula, analisou-se o envolvimento dos alunos nas aulas de Ciências Físicas, o esforço do professor para induzir esse envolvimento, bem como indicadores de produtividade dos alunos. Com base nas evidências empíricas obtidas, elaborou-se uma proposta de ferramenta de trabalho, adaptável, para apoiar os professores na identificação de indicadores do envolvimento produtivo dos seus alunos na disciplina e de possíveis modos de os professores envolverem os alunos na disciplina de modo produtivo

    Biodegradable polymers on cementitious materials

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    PTDC/EPH-PAT/4684/2014 IF/01054/2014/CP1224/CT0005 UID/QUI/50006/2019 UID/Multi/04378/2019 POCI-01-0145-FEDER-007728Nowadays the sustainability and safety requirements of structures inspire the study of new self healing materials and preventive repair methods on cementitious elements. To achieve this undertaking, this research replaces widely employed synthetic polymers by biodegradable ones as consolidants and water-repellents, and assesses the protection and consolidation effect of biopolymers (obtained by using waste biomass of mixed microbial cultures from polyhydroxyalkanoates production processes) as eco-friendly healing agents by analysing the water absorption of two kind of materials. The first group of samples are cement mortar specimens whose external surface has been treated with biopolymer products and subsequently evaluated by water drop absorption test. The second group of samples are cement mortar specimens formulated with biopolymer products included in its mixing water and later the waterproofing efficiency is analysed by capillary water absorption tests. The water absorption behaviour of both kind of samples shows a potential improvement of cementitious elements durability, since water absorption results have decreased for treated samples in comparison with untreated ones.authorsversionpublishe

    Acute Physiological and Metabolic responses for 40-minutes of Samba Dance

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    Dance is an enjoyable health-promoting physical activity that many people worldwide incorporate into their lifestyles today. Therefore, dance improves your heart health, overall muscle strength, balance, and coordination, and reduces depression. We aim to gain insights into the effects of samba dance on the cardiorespiratory and metabolic response during an acute session of this dance style for 40-minutes. The study was carried out on 20 female samba dancers. All of them performed two procedures: (1) a cardiopulmonary exercise test on a treadmill for physical fitness aptitude verification and (2) a 40-minutes of samba dancing monitored by analysis of expired gases. The results were: At peak exercise: oxygen uptake (VO2) =32.7 mL.kg-1.min-1; heart rate (HR) =183 bpm; the pulse of oxygen (PO2) =10.9 mL.HR-1, energy expenditure (EE) = 9.9 kcal.min-1and metabolic equivalent (METs)=13.5.Overall, each session of the dance of 40-minutes was performed at a mean VO2 of 22.8 mL.kg-1.min-1 (70%VO2max), heart rate of 162 bpm (89%HRmax), energy expenditure (EE) of 6.5 kcal.min-1 (66%max), metabolic equivalent (METs) of 6.3 (62%max), and the rate of perceived exertion (RPE) of 11.8/20. In conclusion: The findings of the current investigation might suggest that the moderate and vigorous-intensity of the exercise verified in an acute samba dance session is enough to induce a chronic training effect recommended by the criteria established by the American College of Sports Medicine for improving cardiorespiratory fitness. This information may lead to a better understanding of the energy expenditure of samba dance and add to the compendium of physical activity.

    Eco-friendly healing agents for recycled concrete

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    Abstract An innovative option to extend the service life of construction and building materials is the use of bio-healing agents. This study was focused on assessing the protection and consolidation effect of eco-friendly healing agents by analysing the water absorption of recycled concrete. A recycled concrete with 50% replacement of natural coarse aggregate by construction and demolition waste (CDW) aggregate and a similar recycled concrete in which, additionally, the Portland cement was replaced by recycled cement (with 25% ceramic waste) were biotreated by healing agents. These agents were obtained by using waste biomass of two different mixed microbial cultures from polyhydroxyalkanoates production processes. Results have shown that biotreatments decreased the water absorption significantly, more evident in concrete samples with both recycled cement and aggregates than on the other type of concrete. Resumen Una innovadora posibilidad planteada para prolongar la vida útil de los materiales de construcción y edificación es el uso de agentes bioreparadores. Este estudio se centró en la evaluación del efecto protector y consolidante de agentes reparadores y respetuosos con el medio ambiente mediante el análisis de la absorción de agua del hormigón reciclado. Un hormigón reciclado con sustitución del 50% de los áridos gruesos naturales por residuos de construcción y demolición (RCD) y un hormigón reciclado similar en el cual, además, se sustituyó el cemento convencional Portland por cemento reciclado (con 25% de residuo cerámico) fueron biotratados con agentes reparadores. Estos agentes se obtuvieron en el proceso de producción de polihidroxialcanoatos utilizando biomasa residual de dos cultivos microbianos mixtos diferentes. Los resultados mostraron que los biotratamientos disminuyen significativamente la absorción de agua del hormigón, siendo más eficaces en las muestras de hormigón que combinan cemento y árido reciclado que en el otro tipo de hormigón.authorsversionpublishe

    In vitro evaluation of sequestering agents for aflatoxins

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    La presencia de micotoxinas en alimentos es un problema de gran importancia a nivel mundial que provoca serios perjuicios sanitarios y económicos. Para limitar los efectos de las micotoxinas a los animales uno de los métodos más utilizados es la aplicación de secuestrantes. Estos son polímeros inorgánicos u orgánicos que al añadirse a los alimentos forman complejos con las micotoxinas en la luz intestinal disminuyendo así su absorción. Por este motivo se evaluó la eficacia de cuatro secuestrantes, dos alumino silicatos hidratados de calcio y sodio, uno de glucomananos esterificados y otro del tipo multi modular para aflatoxina B1 (AFB1). La capacidad de adsorción fue evaluada in vitro y bajo condiciones de pH similares a las del tracto gastrointestinal de los animales. La concentración de AFB1 fue determinada mediante cromatografía líquida de alta resolución (HPLC). Con la excepción del producto de glucomananos esterificados, el porcentaje de unión de aflatoxina B1 obtenido para los secuestrantes estudiados fue alto (> 76%). Estos resultados sugieren que la mayoría de los secuestrantes utilizados en este estudio son potenciales agentes químicos-biológicos que podrían ser utilizados para disminuir los efectos de las aflatoxinas en animales.The contamination of animal feed with mycotoxins represents a worldwide problem that causes serious diseases in animals and economic losses. One of the most used methods for protecting animals against mycotoxins is the utilization of adsorbents. These are inorganic or organic components that added to foods form complexes with mycotoxins in the gastrointestinal tract thus decreasing its absorption. Four mycotoxin binder products including two hydrated sodium calcium aluminosilicates, one esterified glucomannan and one multi modular were used to determine their efficacity to bind aflatoxin B1. The binding ability for AFB1 was conducted by an in vitro assay, which simulated the pH condition of the gastrointestinal tract of animals. AFB1 contents was determinated by high performance liquid chromatographic (HPLC). With the exception of the esterified glucomannan product, the binding percent of AFB1 was high (> 76%) by the sequestering agents used in the current study. These results suggest that most commercial adsorbent products used in this study are potential chemical - biological agents that might be used to decrease the effects of aflatoxins in animals

    A role for microRNAs in the epigenetic control of sexually dimorphic gene expression in the human placenta

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    Aim: The contribution of miRNAs as epigenetic regulators of sexually dimorphic gene expression in the placenta is unknown. Materials & methods: 382 placentas from the extremely low gestational age newborns (ELGAN) cohort were evaluated for expression levels of 37,268 mRNAs and 2,102 miRNAs using genome-wide RNA-sequencing. Differential expression analysis was used to identify differences in the expression based on the sex of the fetus. Results: Sexually dimorphic expression was observed for 128 mRNAs and 59 miRNAs. A set of 25 miRNA master regulators was identified that likely contribute to the sexual dimorphic mRNA expression. Conclusion: These data highlight sex-dependent miRNA and mRNA patterning in the placenta and provide insight into a potential mechanism for observed sex differences in outcomes
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