Abstract
Symptomatic intradialytic hypotension (IDH) continues to be an important complication of hemodialysis treatment. There is some evidence that besides an IDH episode, repeated episodes could represent an even more important independent risk factor for mortality in hemodialysis patients. A retrospective cross-sectional study was performed to study 18 dialysis treatments in 43 patients during 6 weeks. Relationships of IDH episodes with baseline variables were examined using a Poisson regression model (generalized linear model). IDH was frequent (93% of patients) and highly variable by patient (0%-100%). Multivariate analysis showed that patients who experienced frequent hypotensive episodes had a lower dry weight (90% confidence interval [CI]: 0.95-0.99), higher phosphorus levels (90% CI: 1.07-1.47), greater prevalence of diabetes mellitus (90% CI: 1.11-2.71), and hypertension (90% CI: 1.04-2.45). Dry weight, hypertension, and phosphorus levels are modifiable risk factors to possibly reduce the rate of IDH episodes. The potential protective role of phosphorus warrants further investigation.

Abstract
Several guidelines recommend the importance of educating the patient about the care of vascular access. Nurses have a key role in promoting the development of self-care behaviors by providing the necessary knowledge to patients, so that they develop the necessary skills to take care of the arteriovenous fistula (AVF). This article describes the process of building a scale of assessment of self-care behaviors with arteriovenous fistula in hemodialysis (ASBHD-AVF). This is a cross-sectional study in which the development, construction, and validation process followed the directions of the authors Streiner and Norman. This is a convenience sample, sequential, and nonprobabilistic constituted by 218 patients. The study was conducted in two stages during 2012-2014. The first phase corresponds to the scale construction process, 64 patients participated, while the second corresponds to the evaluation of metric properties and 154 patients participated. The principal component analysis revealed a two-factor structure, with factorial weights between 0.805 and 0.511 and between 0.700 and 0.369, respectively, explaining 39.12% of the total variance of the responses. The Cronbach's alpha of the subscale management of signs and symptoms is 0.797 and from the subscale prevention of complications is 0.722. The ASBHD-AVF revealed properties that allow its use to assess the self-care behaviors in the maintenance and conservation of the AVF.

Abstract
Aims and objectives. We developed a scale to assess the self-care behaviours developed by patients with end-stage renal disease to preserve the vascular network prior to construction of arteriovenous fistula. Background. The possibility of creation of an arteriovenous fistula depends on the existence of an arterial and venous network in good condition, namely the size and elasticity of the vessels. It is essential to teach the person to develop self-care behaviours for the preservation of the vascular network, regardless of the modality of dialysis selected. Design. Methodological study. Methods. The scale was developed based on clinical experience and research conducted by the researcher in the area of the vascular access for haemodialysis. The content of the scale was judged by two panels of experts for content validity. The revised version of the scale was administered to a convenience sample of 90 patients with end-stage renal disease. In the statistical analysis, we used the Cronbach's alpha, the Kaiser-Meyer-Olkin and scree plot and the principal component analysis with varimax rotation. Results. A principal component analysis confirmed the univariate structure of the scale (KMO = 0.759, Bartlett's sphericity test-approximate chi(2) 142.201, p < 0.000). Cronbach's a is 0.831, varying between 0.711-0.879. Conclusion. This scale revealed properties that allow its use to assess the patients self-care behaviours regarding the preservation of the vascular network. Relevance to clinical practice. This scale can be used to evaluate educational programmes for the development of self-care behaviours in the preservation of vascular network. This scale can identify not only the patients that are able to take care of their vascular network but also the proportion of patients who are not able to do it, that need to be educated.

Abstract

Abstract
Wind energy production have been increasing in last years, with an annual growth of the installed capacity rate about 20%. It becomes important to develop optimization techniques to improve the effectiveness of the wind farms. One field in which this can be done is in the distribution network design that interconnects the turbines and the substation. This paper proposes two mathematical models to obtain the optimal electrical interconnection configuration of the wind farm turbines, considering technical constraints. One model minimizes the installation costs and the other one minimizes the installation costs and the energy losses costs registered during the wind farm lifetime. This problem corresponds to a capacitated minimum spanning tree with additional constraints. The proposed models were applied in two real wind farms. A sensitivity analysis is performed over two electrical parameters, the power factor and the load factor. The results show that the electrical losses of the wind farm must be taken into account in the optimization process.

Abstract
Childhood obesity is according to the World Health Organization one of the most concerning problems today. Educating children to a healthier lifestyle is a difficult task due to the lack of interest or concern that they demonstrate. The interest that children have in technology and the time they spent online in games or simply surfing the web may be seen as an opportunity to instill knowledge about healthy eating and healthy lifestyle. There are already several online health counseling websites but it seems to exist a lack of such platforms directly towards to children. Afina-te website is an online platform that aims to monitor and educate children to a healthier lifestyle through the exposition of information, interactive applications and educational games. It is also capable of provide feedback about what users eat and the exercise they practice. This paper describes the development and resulting health counseling website.