Laplace Approximation for Divisive Gaussian Processes for Nonstationary Regression

The standard Gaussian Process regression (GP) is usually formulated under stationary hypotheses: The noise power is considered constant throughout the input space and the covariance of the prior distribution is typically modeled as depending only on the difference between input samples. These assumptions can be too restrictive and unrealistic for many real-world problems. Although nonstationarity can be achieved using specific covariance functions, they require a prior knowledge of the kind of nonstationarity, not available for most applications. In this paper we propose to use the Laplace approximation to make inference in a divisive GP model to perform nonstationary regression, including heteroscedastic noise cases. The log-concavity of the likelihood ensures a unimodal posterior and makes that the Laplace approximation converges to a unique maximum. The characteristics of the likelihood also allow to obtain accurate posterior approximations when compared to the Expectation Propagation (EP) approximations and the asymptotically exact posterior provided by a Markov Chain Monte Carlo implementation with Elliptical Slice Sampling (ESS), but at a reduced computational load with respect to both, EP and ESS

An Educational Intervention To Improve Antibiotic Use In The Center Region of Portugal

Microbial resistances are one of the most important problems of public health, and it has been associated to the misuse of antibiotics. Inadequate antibiotic prescription and self-medication (with antibiotic leftovers or by acquiring antibiotics directly in the pharmacy without a prescription), are behaviours directly related with this misuse, revealing the necessity of interventions directed to health professionals. Accordingly this, our aim is to improve the consumption of antibiotics through an educational intervention directed to community pharmacists and primary care physicians

Effectiveness of Interventions to Reduce Potentially Inappropriate Medication in Older Patients: A Systematic Review

Background: Age-related multiple comorbidities cause older adults to be prone to the use of potentially inappropriate medicines (PIM) resulting in an increased risk of adverse events. Several strategies have emerged to support PIM prescription, and a huge number of interventions to reduce PIM have been proposed. This work aims to analyze the effectiveness of PIM interventions directed to older adults. Methods: A systematic review was performed searching the literature in the MEDLINE PubMed, EMBASE, and Cochrane scientific databases for interventional studies that assessed the PIM interventions in older adults (≥65 years). Results: Forty-seven articles were included, involving 52 to 124,802 patients. Various types of interventions were analyzed such as medication review, educational strategies, clinical decision support system, and organizational and multifaceted approaches. In the hospital, the most successful intervention was medication review (75.0%), while in primary care, the analysis of all included studies revealed that educational strategies were the most effective. However, the analysis of interventions that have greater evidence by its design was inconclusive. Conclusion: The results obtained in this work suggested that PIM-setting-directed interventions should be developed to promote the wellbeing of the patients through PIM reduction. Although the data obtained suggested that medication review was the most assertive strategy to decrease the number of PIM in the hospital setting, more studies are necessary

Effects of supplements with different protein contents on nutritional performance of grazing cattle during the rainy season

The objective of this study was to evaluate the effects of supplements with different crude protein (CP) contents on grazing cattle intake, digestibility, ruminal fermentation pattern, and nitrogen (N) metabolism characteristics during the rainy season. Five ruminal and abomasal cannulated Holstein×Zebu steers (296 kg body weight, BW) were used in a 5×5 Latin square design. The animals grazed five signal grass paddocks (0.34 ha). The five treatments evaluated were: Control (no supplement) and 1.0 g of supplement/kg BW with 0, 330, 660, and 1,000 g of CP/kg as-fed. The supplement was composed of starch, soybean meal, urea, and ammonium sulphate. There was a positive linear effect (p≤0.033) of the CP content in the supplements on the organic matter (OM), CP, and digested OM intakes. The provision of supplements did not increase (p≥0.158), on average, total and ruminal digestibilities of OM and CP. However, the increase in CP content in the supplements caused a positive linear effect (p≤0.018) on ruminal digestibilities of OM and CP. Additionally, a quadratic effect of the CP contents of the supplements were observed (p = 0.041) for the ruminal digestibility of neutral detergent fiber corrected for ash and protein, with the highest estimate obtained with the CP content of 670 g/kg. The supply of supplements increased (p<0.001) the ruminal ammonia N concentration, which also changed linearly and positively (p<0.001) according to increase in CP content in the supplements. The apparent N balance and relative N balance (g/g N intake) were not, on average, changed (p≥0.164) by the supplements supply. However, both showed a tendency of a linear increase (p≤0.099) with increasing supplement CP content. The supplements increased (p = 0.007) microbial N production in the rumen, which also changed linearly and positively (p = 0.016) with increasing supplement CP content. In conclusion, protein supplementation in grazing cattle during the rainy season, while stimulating voluntary forage intake, results in higher efficiency of N utilization when compared to energy supplementation. This is a possible response to increased microbial protein synthesis in the rumen and improved N status in the animal body

Optical projection tomography technique for image texture and mass transport studies in hydrogels based on gellan gum

The microstructure and permeability are crucial factors for the development of hydrogels for tissue engineering, since they influence cell nutrition, penetration and proliferation. The currently available imaging methods able to characterize hydrogels have many limitations. They often require sample drying and other destructive processing, which can change hydrogel structure, or they have limited imaging penetration depth. In this work, we show for the first time an alternative non-destructive method, based on optical projection tomography (OPT) imaging, to characterize hydrated hydrogels without the need of sample processing. As proof of concept we used gellan gum (GG) hydrogels obtained by several crosslinking methods. Transmission mode OPT was used to analyse image microtextures and emission mode OPT to study mass transport. Differences in hydrogels structure related to different types of crosslinking and between modified and native GG were found through the acquired Haralickâ s image texture features followed by multiple discriminant analysis (MDA). In mass transport studies, the mobility of FITC-dextran (MW 20, 150, 2000 kDa) was analysed through the macroscopic hydrogel. The FITC-dextran velocities were found to be inversely proportional to the size of the dextran as expected. Furthermore, the threshold size in which the transport is affected by the hydrogel mesh was found to be 150 kDa (Stokesâ radii between 69 à and 95 à ). On the other hand, the mass transport study allowed us to define an index of homogeneity to assess the crosslinking distribution, structure inside the hydrogel and repeatability of hydrogel production. As a conclusion,  we showed that  the set of OPT imaging based material characterization methods presented here are useful for screening many characteristics of hydrogel compositions in relatively short time in an inexpensive manner, providing  tools for improving the process of designing hydrogels for tissue engineering and drugs/cells delivery applications.Portuguese Foundation for Science and Technology (FCT) - Grant No. SFRH/BPD/100590/201

Magnitude and determinants of antibiotic dispensing without prescription in Spain: a simulated patient study

Objectives: Excessive and inappropriate use of antibiotics increases antimicrobial resistance. The aim of this study was to determine the magnitude and determinants of antibiotic dispensing without prescription in Spain by the simulated patient technique. Methods: A cross-sectional study was conducted with all the pharmacies in a region of north-west Spain (n = 977), between December 2016 and January 2017. Four actors visited the pharmacies simulating a respiratory infection. Four incremental levels of pressure were used to obtain an antibiotic. The education and sex of the person who was dispensing and the area where the pharmacy was located were recorded. The effect of these independent variables on the dispensing of an antibiotic without prescription (1 = yes, 0 = no) was modelled by logistic regression. Results: An antibiotic was obtained in 18.83% (95% CI = 16.5%-21.41%) of the visits. The area influenced the dispensing of antibiotics without a medical prescription, with a greater likelihood of dispensing in rural (OR = 1.79; 95% CI = 1.20-2.68) or semi-rural (OR = 1.66; 95% CI = 1.13-2.44) areas than in urban areas. No association was found with the sex or the training of the person who dispensed the antibiotic. In the pharmacies in urban areas, a lower level of pressure was needed to obtain the antibiotic. Conclusions: This study shows that one-fifth of the pharmacies still dispense antibiotics without prescription, especially under patient pressure. A rural setting has been identified as a risk factor for dispensing without prescription, so it must be taken into account for future interventions

Proposta de tutorial de quimiometria utilizando técnicas modernas para a análise de solos.

A utilização de técnicas espectroscópicas aplicadas à ciência do solo é recente e promissora. Sua aplicação invariavelmente está associada à Quimiometria. Este trabalho tem por objetivo introduzir os conhecimentos básicos destas duas técnicas para estudantes de pós-graduação e pesquisadores da área de ciência do solo. Para tal, é proposto um tutorial baseado no estudo de 52 amostras de solos obtidas no município de Manga, norte de Minas Gerais, coletadas em perfis de diferentes classes de solos, contrastantes em relação aos seus atributos químicos, físicos e mineralógicos. Amostras de solos foram analisadas por Espectroscopia no Infravermelho Próximo (NIR) e os espectros obtidos, avaliados por Análise por Componentes Principais (PCA). Os resultados apresentados e sua forma de apresentação possibilitam, aos alunos e professores em nível de graduação e pós-graduação da área de ciência do solo, uma introdução prática da PCA em Matlab, ainda pouco divulgada na literatura mundial

Optical projection tomography as a tool for 3D imaging of hydrogels

An Optical Projection Tomography (OPT) system was developed and optimized to image 3D tissue engineered products based in hydrogels. We develop pre-reconstruction algorithms to get the best result from the reconstruction procedure, which include correction of the illumination and determination of sample center of rotation (CoR). Existing methods for CoR determination based on the detection of the maximum variance of reconstructed slices failed, so we develop a new CoR search method based in the detection of the variance sharpest local maximum. We show the capabilities of the system to give quantitative information of different types of hydrogels that may be useful in its characterization.The authors thank to Tekes, Finnish Cultural Foundation, CIMO, Jane and Aatos Erkko Foundation and EXTREMA COST Action MP1207 for supporting this work