In this work, the fan assisted extraction approach is originally exploited to determine volatile compounds in liquid samples based on the full evaporation technique. The feasibility of this strategy ...was firstly evaluated using model solutions containing different volatile carbonyl compounds. Different media, volumes of sample, temperatures of extraction, and times of extraction were tested. Linear regressions presenting r > 0.999, intermediate precision values < 6%, and recoveries within 76–95% were attained using a period of extraction of 10 min, a volume of sample solution of 5 µL, and a temperature of extraction of 50 °C. Analyses of brewed coffees were performed. The slopes of the calibration curves obtained using aqueous model solutions and brewed coffee samples were not significantly different. These results revealed no matrix effect under the selected experimental conditions, enabling the use of the external calibration method for quantification purposes. Twenty-four volatile carbonyl compounds were identified in brewed coffee, which elucidates the sensitivity of this approach.
Habitat loss and fragmentation are among the greatest threats to biodiversity and ecosystem stability, with physiological implications on wild fauna. Bats (Microchiroptera) are small mammals with a ...wide variety of eating habits, and the well-being of these animals is disturbed by exposure to pesticides. This study aimed to develop a miniaturized QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction method for the detection of multi-residue pesticides in bat muscle tissue using gas chromatography coupled with mass spectrometry (GC-MS). A total of 48 pesticides were tested in 250 mg of bat muscle tissue. The developed analytical method was applied to 148 bats collected from two different areas in Minas Gerais State, Southeast Region of Brazil. The method presented good sensitivity and allowed the determination of residues of 48 pesticides in bat muscle using GC-MS. The miniaturized extraction method makes the analysis feasible even when the sample volume is limited. However, no pesticide residues were detected in bats from the two areas investigated.
Abstract
Background
Hypertension (HT) is highly prevalent and a major risk factor for cardiovascular disease. Over 42% of Portuguese adults have HT. Even though the benefits of antihypertensive (AHT) ...drugs have been demonstrated, HT control remains inadequate. One major reason is that patients often fail to take their medications as prescribed. This paper aims to determine primary adherence to AHT therapy in newly diagnosed and treated hypertensive patients in Primary Health Care (PHC) units of Lisbon and Tagus Valley Health Region.
Methods
This study reports data from a population-based, retrospective, cohort study from patients diagnosed with HT in PHC units of Lisbon and Tagus Valley Region from 1 January to 31 March 2011, with no prior use of AHT drugs. Primary adherence rate was expressed as number of claims records/total number of prescriptions records. Data were collected from SIARS for each patient during a 2-year period.
Results
Overall primary adherence rate was 58.5%, increasing with age. Rates were higher for men, living in the Lisbon Metropolitan Area and diagnosed with uncomplicated HT. Drugs acting on the renin–angiotensin system had the highest rates, increasing for fixed-dose combinations and diminishing with the increase of cost for the patient.
Conclusions
Overall, almost 1 out of 2 prescribed AHT drugs were not dispensed. Until this study, little was known in Portugal about primary adherence. Our findings imply that the potential benefits of AHT therapy cannot be fully realized in this population.
Abstract Objective We carry out a systematic assessment on a suite of kernel-based learning machines while coping with the task of epilepsy diagnosis through automatic electroencephalogram (EEG) ...signal classification. Methods and materials The kernel machines investigated include the standard support vector machine (SVM), the least squares SVM, the Lagrangian SVM, the smooth SVM, the proximal SVM, and the relevance vector machine. An extensive series of experiments was conducted on publicly available data, whose clinical EEG recordings were obtained from five normal subjects and five epileptic patients. The performance levels delivered by the different kernel machines are contrasted in terms of the criteria of predictive accuracy, sensitivity to the kernel function/parameter value, and sensitivity to the type of features extracted from the signal. For this purpose, 26 values for the kernel parameter (radius) of two well-known kernel functions (namely, Gaussian and exponential radial basis functions) were considered as well as 21 types of features extracted from the EEG signal, including statistical values derived from the discrete wavelet transform, Lyapunov exponents, and combinations thereof. Results We first quantitatively assess the impact of the choice of the wavelet basis on the quality of the features extracted. Four wavelet basis functions were considered in this study. Then, we provide the average accuracy (i.e., cross-validation error) values delivered by 252 kernel machine configurations; in particular, 40%/35% of the best-calibrated models of the standard and least squares SVMs reached 100% accuracy rate for the two kernel functions considered. Moreover, we show the sensitivity profiles exhibited by a large sample of the configurations whereby one can visually inspect their levels of sensitiveness to the type of feature and to the kernel function/parameter value. Conclusions Overall, the results evidence that all kernel machines are competitive in terms of accuracy, with the standard and least squares SVMs prevailing more consistently. Moreover, the choice of the kernel function and parameter value as well as the choice of the feature extractor are critical decisions to be taken, albeit the choice of the wavelet family seems not to be so relevant. Also, the statistical values calculated over the Lyapunov exponents were good sources of signal representation, but not as informative as their wavelet counterparts. Finally, a typical sensitivity profile has emerged among all types of machines, involving some regions of stability separated by zones of sharp variation, with some kernel parameter values clearly associated with better accuracy rates (zones of optimality).
Objetivamos levantar artigos científicos em línguas portuguesa e espanhola relacionados ao ensino de ciências por investigação, sistematizando a produção da literatura nesse campo no que diz respeito ...à natureza dos trabalhos, à distribuição deles ao longo do tempo e ao nível de ensino e disciplinas a eles associados. Realizamos buscas em todas as edições de trinta periódicos eletrônicos classificados nos estratos A1, A2 e B1 da Área de Ensino no Qualis-CAPES quadriênio 2013-2016. Ao todo foram encontrados 101 artigos, metade deles em apenas quatro periódicos. Analisando os resultados obtidos, evidenciamos que: a publicação de trabalhos sobre o ensino por investigação se intensificou apenas a partir de 2014; a maioria deles são de cunho empírico, havendo escassez de artigos de revisão e de artigos que analisam de que maneira essa abordagem se faz presente em recursos como livros didáticos; a maioria dos artigos de cunho empírico se relacionam aos Ensinos Fundamental e Médio, especialmente à Biologia e à Física, havendo certa escassez de trabalhos associados a cursos de Licenciatura e à disciplina Química. Por fim, sugerimos questões que podem auxiliar na ampliação e no aprofundamento deste trabalho.
Abstract The electroencephalogram (EEG) signal captures the electrical activity of the brain and is an important source of information for studying neurological disorders. The proper analysis of this ...biological signal plays an important role in the domain of brain–computer interface, which aims at the construction of communication channels between human brain and computers. In this paper, we investigate the application of least squares support vector machines (LS-SVM) to the task of epilepsy diagnosis through automatic EEG signal classification. More specifically, we present a sensitivity analysis study by means of which the performance levels exhibited by standard and least squares SVM classifiers are contrasted, taking into account the setting of the kernel function and of its parameter value. Results of experiments conducted over different types of features extracted from a benchmark EEG signal dataset evidence that the sensitivity profiles of the kernel machines are qualitatively similar, both showing notable performance in terms of accuracy and generalization. In addition, the performance accomplished by optimally configured LS-SVM models is also quantitatively contrasted with that obtained by related approaches for the same dataset.
The recognition that the gut microbiota of obese children differs from lean children has grown, and some studies suggest that physical activity positively influences the gut microbiota. This ...systematic review explores the changes in the gut microbiota composition of obese and non-obese children and adolescents and provides an understanding of the effects of physical activity interventions in modulating their microbiota. The PRISMA protocol was used across PubMed, Scopus, and Web of Science. Overall, twenty-four research papers were included in accordance with the chosen inclusion and exclusion criteria, eighteen studies compared the gut microbiota of obese and normal-weight children and adolescents, and six studies explored the effect of physical activity interventions on the gut microbiota. The analysis indicated that obese gut microbiota is reduced in Bacteroidetes, Bifidobacterium and alpha diversity but enriched in Proteobacteria and Lactobacillus. Interventions with physical activity seem to improve the alpha diversity and beneficial bacteria linked to body weight loss in children and adolescents. The gut microbiota of obese children exhibited a remarkably individual variation. More interventions are needed to clearly and accurately explore the relationships between child obesity, gut microbiota, and physical activity and to develop approaches to decrease the incidence of paediatric obesity.
Introduction
Noncommunicable diseases and obesity are between the major health threat due to consumption of unhealthy foods and limited time spent on physical activities, a situation of particular ...concern among children. Since children spend most of their time at school, this study intends to investigate the effect of a school intervention program, which combines recreational football and nutrition education, on body composition, physical fitness, physical activity, blood pressure and heart rate, eating behaviours, nutritional knowledge, and psychological status in elementary school children.
Methods
A total of 67 children, between 7 and 10 years old, were allocated into three groups: the Football Group (FG) which held 2 weekly sessions of 60 min of recreational football, the Nutrition and Football Group (NFG) which held 2 sessions per week of 60 min of recreational football plus 60 min of nutritional education and the Control Group (CG) which maintained its usual curriculum. The intervention lasted 12 weeks. All measurements were collected before and after the intervention.
Results
Intervention groups significantly (
p
< 0.05) improved BMI Z-score, rest heart rate, horizontal jump and shuttle test, physical activity level, and psychosocial health. The NFG group significantly decreased (
p
< 0.05) waist-to-height ratio and blood pressure, and significantly increased (
p
< 0.05) nutritional knowledge, fruit, and fish consumption. While FG significantly decreased (
p
< 0.05) the percentage of fat mass and significantly increased (
p
< 0.05) muscle mass and performance in the 20 m sprint.
Discussion
The results have shown to improve nutritional status, explosive strength, aerobic and neuromuscular fitness, as well as increase the level of physical activity. The nutritional education sessions contributed to increase nutritional knowledge and to improve the consumption of healthy food groups in a ludic-educational way. The “Football and Nutrition for Health” program was able to induce short-term improvements in several health markers, highlighting the role of the school curriculum in children's health.
The few construction and demolition waste (CDW) recycling plants that there are in Portugal separate the materials and then crush and sieve them prior to final delivery. These plants have limited ...overall capacity and the quality of the output material is not good enough for higher grade applications such as concrete and brick production. This study aims to better understand the economic implications of implementing and operating a large-scale high-end CDW recycling plant to serve a densely populated urban area in Portugal (Lisbon and its outskirts). This first part deals with the location of the plant, its design and the material entering and leaving it. There follows an economic analysis which leads to the sensitivity analysis presented in part two, which provides important conclusions for the economic viability of full-scale CDW recycling plants. The methodology used can be applied to other locations and resulted, within the regional data frame of the Lisbon Metropolitan area, on a return of the investment period of around 2 years, considering a plant capacity of 350tonne/h, the collection of 21.8million€/year in gate fees and the need to pay around €11.9million€/year in running costs. Hence, there is a high profit potential in this venture, even though considering the high initial investment needs. Moreover, the venture seems economically viable even in the absence of specific regulatory government policy intervention for recycling CDW, which may indicate a clear alignment between economic viability and environmental benefits, arising from this CDW recycling plant operation.
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