Suchergebnisse

This paper proposes the impact assessment of the workers in the optimal time of operations in a Flexible Job Shop Scheduling Problem. In this work, a real enterprise was studied. The problem consists in finding the workers operations schedule, taking into account the precedence constraints. The main objective is to minimize the finish time of the last task completed in the schedule. The genetic algorithm was used to solve the optimization problem and some numerical results are presented. ; The research leading to these results has received funding from the European Union Seventh Framework Programme FP7/2007- 2013 under grant agreement n° 314056. ; info:eu-repo/semantics/publishedVersion

Purpose Parents' underestimation of young children's weight can reduce their engagement and readiness to implement changes in children's diet and physical activity. Childcare teachers can support parents' identification of children at risk for being overweight only if they can accurately do this themselves. Design Quantitative, cross-sectional study. Setting Fifteen kindergartens near Lisbon, Portugal. Subjects 319 parents, 32 teachers (47.5% and 100% response rate, respectively), and 319 children. Measures Caregivers classified the children's weight, considering their height and age as underweight, healthy weight, or overweight; children's body mass index (BMI) status for age and sex was assessed. Analysis Differences in caregivers' accuracy of children's weight perception were assessed. Multilevel multivariate logistic regression models were used to analyze the predictors of the accuracy of teachers' and parents' weight perception as a binary outcome. Results The proportion of children with overweight correctly assessed differed significantly ( P = 0.004) between teachers (31.1%) and parents (17.5%). The child's BMI percentile was the only significant positive predictor for both caregivers' weight perception accuracy ( P < 0.001 and P = 0.004, for parents and teachers, respectively), holding the child's age and sex constant. Conclusion Although childcare teachers were better raters than parents when evaluating children's weight status, the percentage of children with overweight that childcare teachers misclassified was still relatively high.

This paper presents a short overview of teacher´s training as considered by the Portuguese legislation: (i) initial teacher education (ITE), (ii) specialized training and (iii) in-service teacher training. A particular emphasis will be given to in-service teacher training. Nowadays, ITE corresponds to level 7 of the European Qualifications Framework (master degree). It is a career-long professional development, where research-based and in context practice are important features. Specialized training is intended to provide qualification in complementary educational functions, such as special education, school administration and inspection activities, socio-cultural animation and basic education for adults. In-service training or continuous training allows teachers to complement, deepen and update their knowledge and professional competences. Its accreditation, in what concerns involved institutions, training actions and evaluation process is centralized in the "Conselho Científico-Pedagógico da Formação Contínua" (Scientific and Pedagogical Council of in-service training) and has a direct impact in teacher's careers, being one of the factors considered to access mobility and progression.

The cell-free layer (CFL) is a hemodynamic phenomenon that has an important contribution to the rheological properti es of blood flowing in microvessels. The present work aims to find the closest function describing RBCs flowing around the cell depleted layer in a polydimethysiloxane (PDMS) microchannel with a diverging and a converging bifurcation. The flow behaviour of the CFL was investigated by using a high-speed video microscopy system where special attention was devoted to its behaviour before the bifurcation and after the confluence of the microchannel. The numerical data was first obtained by using a manual tracking plugin and then analysed using the genetic algorithm approach. The results show that for the majority of the cases the function that more closely resembles the CFL boundary is the sum of trigonometric functions. ; The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/ 2010 and EXPL/EMS-SIS/2215/2013 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER). R.O. Rodrigues, D. Pinho and V. Faustino acknowledge respectively, the PhD scholarships SFRH/BD/97658/2013, SFRH/BD/89077/2012 and SFRH/BD/99696/2014 granted by FCT. ; info:eu-repo/semantics/publishedVersion

Red blood cells (RBCs) in microchannels has tendency to undergo axial migration due to the parabolic velocity profile, which results in a high shear stress around wall that forces the RBC to move towards the centre induced by the tank treading motion of the RBC membrane. As a result there is a formation of a cell free layer (CFL) with extremely low concentration of cells. Based on this phenomenon, several works have proposed microfluidic designs to separate the suspending physiological fluid from whole in vitro blood. This study aims to characterize the CFL in hyperbolic-shaped microchannels to separate RBCs from plasma. For this purpose, we have investigated the effect of hyperbolic contractions on the CFL by using not only different Hencky strains but also varying the series of contractions. The results show that the hyperbolic contractions with a Hencky strain of 3 and higher, substantially increase the CFL downstream of the contraction region in contrast with the microchannels with a Hencky strain of 2, where the effect is insignificant. Although, the highest CFL thickness occur at microchannels with a Hencky strain of 3.6 and 4.2 the experiments have also shown that cells blockage are more likely to occur at this kind of microchannels. Hence, the most appropriate hyperbolic-shaped microchannels to separate RBCs from plasma is the one with a Hencky strain of 3. ; The authors acknowledge the financial support provided by PTDC/SAU-ENB/116929/2010 and EXPL/EMS-SIS/2215/2013 from FCT (Fundação para a Ciência e a Tecnologia), COMPETE, QREN and European Union (FEDER). R.O. Rodrigues, D. Pinho and P. C. Sousa acknowledge the scholarships SFRH/BD/97658/2013, SFRH/BD/89077/2012 and SFRH/BPD/75258/2010, respectively, all attributed by FCT.

Studies of in vitro blood flow behaviour in stenosis are essential not only as an attempt to understand this phenomenon, but also to develop microfluidic devices, as an alternative clinical methodology to detect blood diseases. Regarding a better understanding of the role that rigid Red Blood Cells (rRBCs) play in the blood flow behaviour, we have studied the trajectories and deformation of both, artificial rigid Red Blood Cells (arRBCs) and healthy ovine Red Blood Cells (RBCs), when subjected to a pronounced microstenosis. By using a high-speed video microscopy system, the present study was performed with different flow rates (1, 10 and 20 µl/min). The results have shown that healthy RBCs and arRBCs present deviations in their flow behaviour and deformation index, which might be a potential alternative clinical methodology to detect blood cells related diseases. ; The authors acknowledge the financial support provided by PTDC/SAU-BEB/105650/2008, PTDC/EME-MFE/099109/2008, PTDC/SAU-ENB/116929/2010, EXPL/EMS-SIS/2215/2013, scholarship SFRH/BD/91192/2012 and scholarship SFRH/BD/89077/2012 from FCT (Science and Technology Foundation), COMPETE, QREN and European Union (FEDER).

In this chapter we discuss the cell-free layer (CFL) developed adjacent to the wall of microgeometries containing complex features representative of the microcirculation, such as contractions, expansions, bifurcations and confluences. The microchannels with the different geometries were made of polydimethylsiloxane (PDMS) and we use optical techniques to evaluate the cell-free layer for red blood cells (RBC) suspensions with different hematocrit (Hct). The images are captured using a high-speed video microscopy system and the thickness of the cell free layer was measured using both manual and automatic image analysis techniques. The results show that in in vitro microcirculation, the hematocrit and the geometrical configuration have a major impact on the CFL thickness. In particular, the thickness of the cell-free layer increases as the fluid flows through a contraction-expansion sequence and that this increase is enhanced for lower hematocrit. In contrast, the flow rates tested in this studies did not show a clear influence on the CFL thickness. ; The authors acknowlcdge the financiaI suppart provided by: PTDC/SAUBEB/l08728/2008, PTDC/SAU-BEB/l05650/2008, PTDC/EME-MFEI099109/2008 and PTDC/SAU-ENB/116929/2010 from FCT (Science and Technnlogy Foundation), COMPETE, QREN and European Union (FEDER). The authors are graterul to Mônica Oliveira for many valuable camments on this study.