987 resultados para environment measurements
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Teaching and learning computer programming is as challenging as difficult. Assessing the work of students and providing individualised feedback to all is time-consuming and error prone for teachers and frequently involves a time delay. The existent tools and specifications prove to be insufficient in complex evaluation domains where there is a greater need to practice. At the same time Massive Open Online Courses (MOOC) are appearing revealing a new way of learning, more dynamic and more accessible. However this new paradigm raises serious questions regarding the monitoring of student progress and its timely feedback. This paper provides a conceptual design model for a computer programming learning environment. This environment uses the portal interface design model gathering information from a network of services such as repositories and program evaluators. The design model includes also the integration with learning management systems, a central piece in the MOOC realm, endowing the model with characteristics such as scalability, collaboration and interoperability. This model is not limited to the domain of computer programming and can be adapted to any complex area that requires systematic evaluation with immediate feedback.
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Introduction: The 2D:4D digit ratio is sexually-dimorphic, probably due to testosterone action through the perinatal period. We characterize the 2D:4D ratio in newborn (NB) infants, in between the pre- and postnatal surges of testosterone, and relate it to the mother's 2D:4D and to testosterone levels in the amniotic fluid (AF). Subjects and methods: Testosterone was assayed in samples of maternal plasma and AF collected at amniocentesis. Shortly after birth, 106 NBs and their mothers were measured for 2D:4D ratio. Results: NB males had lower mean 2D:4D ratios than females but this dimorphism was significant only for the left hand (males: 0.927; females: 0.950; p=0.004). Mothers who had sons had lower 2D:4D ratios than those who had daughters and the mother's 2D:4D were higher than those of NBs regardless of sex. Both hands of NB females were negatively correlated with AF testosterone and positively correlated with the mother's 2D:4D, but males showed no significant associations. Maternal plasma testosterone also showed a negative weak correlation with NB's digit ratio in both sexes. Conclusions: Sexual dimorphism at birth was only significant for the left hand, in contrast with reports of greater right hand dimorphism, suggesting that postnatal testosterone is determinant for 2D:4D stabilization. The lower 2D:4D ratios in mothers who had sons support claims that hormone levels in parents are influential for determining their children's sex. NB female's digit ratio, but not males', was associated to the level of AF testosterone. The mother's 2D:4D ratios were positively correlated with their daughters' 2D:4D, but the same was not observed for male NBs, suggesting that prenatal testosterone levels in male fetus lead their 2D:4D ratios to stray from their mothers' with high individual variability.
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With the objective to study the variation of optical properties of rat muscle during optical clearing, we have performed a set of optical measurements from that kind of tissue. The measurements performed were total transmittance, collimated transmittance, specular reflectance and total reflectance. This set of measurements is sufficient to determine diffuse reflectance and absorbance of the sample, also necessary to estimate the optical properties. All the performed measurements and calculated quantities will be used later in inverse Monte Carlo (IMC) simulations to determine the evolution of the optical properties of muscle during treatments with ethylene glycol and glucose. The results obtained with the measurements already provide some information about the optical clearing treatments applied to the muscle and translate the mechanisms of turning the tissue more transparent and sequence of regimes of optical clearing.
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Dissertação para obtenção do Grau de Doutor em Estatística e Gestão do Risco, especialidade em Estatística
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This research aimed to describe the frequency of parasites in stool samples in the environment of Ilha da Marambaia, Rio de Janeiro, Brazil. One hundred and five stool samples were collected and processed by the coproparasitological techniques ethyl acetate sedimentation and centrifuge-flotation using saturated sugar solution. Parasites were detected in 81.9% of the samples, hookworm being the most prevalent, followed by Trichuris vulpis. Ascaris sp. eggs were also found. A high level of evolutive forms of parasites with public health risk was found in stool samples of the environment studied. We propose that health education programs, allied to an improvement of human and animal health care, must be employed to reduce the environmental contamination.
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Dissertação para obtenção do Grau de Doutor em Ambiente, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia
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Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.
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Ligand K-edge XAS of an [Fe3S4]0 model complex is reported. The pre-edge can be resolved into contributions from the í2Ssulfide, í3Ssulfide, and Sthiolate ligands. The average ligand-metal bond covalencies obtained from these pre-edges are further distributed between Fe3+ and Fe2.5+ components using DFT calculations. The bridging ligand covalency in the [Fe2S2]+ subsite of the [Fe3S4]0 cluster is found to be significantly lower than its value in a reduced [Fe2S2] cluster (38% vs 61%, respectively). This lowered bridging ligand covalency reduces the superexchange coupling parameter J relative to its value in a reduced [Fe2S2]+ site (-146 cm-1 vs -360 cm-1, respectively). This decrease in J, along with estimates of the double exchange parameter B and vibronic coupling parameter ì2/k-, leads to an S ) 2 delocalized ground state in the [Fe3S4]0 cluster. The S K-edge XAS of the protein ferredoxin II (Fd II) from the D. gigas active site shows a decrease in covalency compared to the model complex, in the same oxidation state, which correlates with the number of H-bonding interactions to specific sulfur ligands present in the active site. The changes in ligand-metal bond covalencies upon redox compared with DFT calculations indicate that the redox reaction involves a two-electron change (one-electron ionization plus a spin change of a second electron) with significant electronic relaxation. The presence of the redox inactive Fe3+ center is found to decrease the barrier of the redox process in the [Fe3S4] cluster due to its strong antiferromagnetic coupling with the redox active Fe2S2 subsite.
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Introduction: Highly Active Antiretroviral Therapy (HAART) has improved and extended the lives of thousands of people living with HIV/AIDS around the world. However, this treatment can lead to the development of adverse reactions such as lipoatrophy/lipohypertrophy syndrome (LLS) and its associated risks. Objective: This study was designed to assess the prevalence of self-reported lipodystrophy and nutritional status by anthropometric measurements in patients with HIV/AIDS. Methods: An observational study of 227 adult patients in the Secondary Immunodeficiencies Outpatient Department of Dermatology, Hospital das Clínicas, Faculty of Medicine, University of São Paulo (3002 ADEE-HCFMUSP). The sample was divided into three groups; Group 1 = 92 patients on HAART and with self-reported lipodystrophy, Group 2 = 70 patients on HAART without self-reported lipodystrophy and Group 3 = 65 patients not taking HAART. The nutritional status of individuals in the study sample was determined by body mass index (BMI) and percentage of body fat (% BF). The cardiovascular risk and diseases associated with abdominal obesity were determined by waist/hip ratio (WHR) and waist circumference (WC). Results: The prevalence of self-reported lipoatrophy/lipohypertrophy syndrome was 33% among women and 59% among men. Anthropometry showed depletion of fat mass in the evaluation of the triceps (TSF) in the treatment groups with HAART and was statistically independent of gender; for men p = 0.001, and for women p = 0.007. Similar results were found in the measurement of skin folds of the upper and lower body (p = 0.001 and p = 0.003 respectively). In assessing the nutritional status of groups by BMI and % BF, excess weight and body fat were more prevalent among women compared to men (p = 0.726). The WHR and WC revealed risks for cardiovascular and other diseases associated with abdominal obesity for women on HAART and with self-reported LLS (p = 0.005) and (p = 0.011). Conclusions: Anthropometric measurements were useful in the confirmation of the prevalence of LLS. BMI alone does not appear to be a good parameter for assessing the nutritional status of HIV-infected patients on HAART and with LLS. Other anthropometric measurements are needed to evaluate patients with the lipoatrophy/lipohypertrophy syndrome.
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Dermatophytosis is a common zoonosis in urban centers. Dogs and cats have played an important role as its disseminators. Environmental decontamination is essential for the prevention of its propagation to humans and animals. However, sanitizers or disinfectants with antifungal activity, currently available, have high toxicity. The present study evaluated the in vitro effects of an extract of citronella (Cymbopogon nardus) on 31 Microsporum canis isolates from animals and home environments. Susceptibility tests were performed based on document M38-A2 (2008) of the Clinical and Laboratory Standards Institute with modifications for natural products. Although susceptibility variation was observed between the fungus tested, the concentrations that inhibited the growth of 50 and 90% of the microorganisms were low (19.5 and 78 µg/mL, respectively). Thus, this citronella extract showed potent fungistatic and fungicide activities against M. canis isolated from animals and home environments. Therefore, it could be an alternative for dermatophytosis prophylaxis in the home environment.
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Dissertação para obtenção do Grau de Mestre em Engenharia Informática
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Background: Indoor air quality (IAQ) is considered an important determinant of human health. The association between exposure to volatile organic compounds, particulate matter, house dust mite, molds and bacteria in day care centers (DCC) is not completely clear. The aim of this project was to study these effects. Methods --- study design: This study comprised two phases. Phase I included an evaluation of 45 DCCs (25 from Lisbon and 20 from Oporto, targeting 5161 children). In this phase, building characteristics, indoor CO2 and air temperature/relative humidity, were assessed. A children’s respiratory health questionnaire derived from the ISAAC (International Study on Asthma and Allergies in Children) was also distributed. Phase II encompassed two evaluations and included 20 DCCs selected from phase I after a cluster analysis (11 from Lisbon and 9 from Oporto, targeting 2287 children). In this phase, data on ventilation, IAQ, thermal comfort parameters, respiratory and allergic health, airway inflammation biomarkers, respiratory virus infection patterns and parental and child stress were collected. Results: In Phase I, building characteristics, occupant behavior and ventilation surrogates were collected from all DCCs. The response rate of the questionnaire was 61.7% (3186 children). Phase II included 1221 children. Association results between DCC characteristics, IAQ and health outcomes will be provided in order to support recommendations on IAQ and children’s health. A building ventilation model will also be developed. Discussion: This paper outlines methods that might be implemented by other investigators conducting studies on the association between respiratory health and indoor air quality at DCC.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
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Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.