Perception, Personal Issues, and Environment of E-Learning: A Causal Model on Student Attitude Towards Online Learning

This study determined the best-fit model for attitude towards online learning of grade 12 students in Region XI based on perception on e-learning, personal issues on e-learning, and the environment of e-learning. This study employed a causal study design and a stratified sampling technique in selecting the 400 respondents. With the electronic survey facility through Google Forms, data were collected utilizing standardized adapted questionnaires. The study utilized the mean, standard deviation, Pearson’s product-moment correlation, regression analysis, and structural equation model as statistical tools. Results revealed that the level of student perception on e-learning was high; the level of their personal issues on e-learning was high; the level of e-learning environment was high; and the level of attitude towards online learning was high. Moreover, a significant relationship existed between the exogenous and endogenous variables. Furthermore, perception on e-learning, personal issues on e-learning, and the e-learning environment influence the attitude towards online learning. Finally, among the five generated models, Model 5 best-fitted student attitude towards online learning in terms of interest in computers and adoption of online learning and ease-ness in using online learning, with perception on e-learning in terms of perceived usefulness of e-learning and perceived self-efficacy of using e-learning; personal issues on e-learning in terms of health, conflict resolution, and motivation; and environment of e-learning in terms of ethics and professionalism, and program effectiveness. Keywords:educational management, perception on e-learning, personal issues on e-learning, e-learning environment, attitude towards online learning, structural equation model, Philippines DOI: 10.7176/JEP/14-15-08 Publication date:May 31st 202

Pressure dependence of the melting mechanism at the limit of overheating in Lennard-Jones crystals

We study the pressure dependence of the melting mechanism of a surface free Lennard-Jones crystal by constant pressure Monte Carlo simulation. The difference between the overheating temperature($T_{OH}$) and the thermodynamical melting point($T_M$) increase for increasing pressure. When particles move into the repulsive part of the potential the properties at $T_{OH}$ change. There is a crossover pressure where the volume jump becomes pressure-independent. The overheating limit is pre-announced by thermal excitation of big clusters of defects. The temperature zone where the system is dominated by these big clusters of defects increases with increasing pressure. Beyond the crossover pressure we find that excitation of defects and clusters of them start at the same temperature scale related with $T_{OH}$.Comment: 6 pages, 5 figures. Accepted for publication in Physical Review

Diamagnetic interactions in superheated-superconducting microgranules under an external magnetic field

L'estudi de les transicions produïdes en conjunts de grànuls superconductors metastables té nterès tant per a la física fonamental com per a aplicacions com ara els detectors de partícules. L'estudi teòric d'aquest problema ha estat obstaculitzat per la dificultat del tractament de les interaccions diamagnètiques entre grànuls. En aquesta revisió descrivim el comportament d'aquests sistemes, desenvolupem el mètode numèric del tractament i presentem uns quants resultats experimentals i numèrics.The study of the phase transitions produced in ensembles of metastable superconducting granules by magnetic field variations is important both for fundamental physics and for applications in particle detectors. Theoretical study of the problem has long been hampered by the difficulty in dealing with the diamagnetic interactions between granules. In this review we describe the behaviour of such systems, develop numerical procedures to deal with them, and present some experimental and numerical results

Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software

[EN] The development of powerful computer-assisted sperm analysis software has made kinetic studies of spermatozoa possible. This system has been used and validated for several species, but some technical questions have emerged regarding fish sample evaluations (i.e., frame rate, sperm dilution, chamber model, time of analysis, magnification lens, etc.). In the present study, we have evaluated the effects of different procedural and biological settings with the aim to correctly measure sperm quality parameters of the European eel. The use of different chambers did not affect the sperm motility parameters. However, regarding lens magnification, 10x was the most accurate lens, showing the least variation in the acquired data. Similarly, the frame rate setting resulted in a dramatic effect in some sperm kinetic parameters, primarily in terms of curvilinear velocity; we therefore recommend using the camera's highest available frame rate setting. Finally, the reduction in sperm motility over postactivation times suggests that sperm analysis should be performed within the first 60 seconds after activation of the European eel sperm. In conclusion, some protocol variables of sperm analysis by computer-assisted sperm analysis software can affect the measurement of eel sperm quality parameters, and should be considered before directly comparing results obtained by different laboratories. Moreover, because marine fish species show relatively similar features of sperm kinetic parameters, these results could be considered in the evaluation of the motility of sperm from other fish species. (C) 2013 Elsevier Inc. All rights reserved.This study was funded from the European Community's 7th Framework Programme under the Theme 2 "Food, Agriculture and Fisheries, and Biotechnology," grant agreement 245257 (Pro-Eel), and Generalitat Valenciana (ACOMP/2011/229). D.S.P. and P.C.F.C. have postdoctoral grants from UPV (CE-01-10) and PAC-EMBRAPA, respectively. I.M. and V.G. have predoctoral grants from Generalitat Valenciana and Spanish MICINN, respectively. The authors thank the Proiser R&D, S.L. team, who performed the task of fractioning the original sequences for the experiment described in section 3.2.Gallego Albiach, V.; Carneiro, PCF.; Mazzeo, I.; Vilchez Olivencia, MC.; Peñaranda, D.; Soler, C.; Pérez Igualada, LM.... (2013). Standardization of European eel (Anguilla anguilla) sperm motility evaluation by CASA software. Theriogenology. 79(7):1034-1040. https://doi.org/10.1016/j.theriogenology.2013.01.019S1034104079

Nueva metodología para el cálculo de transformadores en convertidores de potencia multinivel

(Eng) This paper presents a new methodology for the correct design of transformers used in power multilevel inverters common source type. The proposed methodology represents a solution to the problems of distortion in the waveform, voltage drop and loss of efficiency caused by the miscalculation of the transformer using conventional methodology. To validate the methodology two prototypes under different perspectives were built, conventional and proposed, in order to verify the results, which support the solution to the problems described and shown an improvement in performance of the power converter.(Spa) En este trabajo se presenta una nueva metodología para el correcto diseño de transformadores utilizados en inversores de potencia multinivel tipo fuente común. La metodología propuesta representa una solución a los problemas de distorsión en la forma de onda, decaimiento de pulsos en la tensión y pérdida de rendimiento causada por el cálculo del transformador utilizando la metodología convencional. Para validar la metodología se construyen dos prototipos bajo diferentes perspectivas, convencional y propuesta, con el fin de verificar de forma experimental la solución a los problemas descritos y mostrar la mejoría en el rendimiento del convertidor de potencia

Prevalence of parasite intestinal infections in a rural community of the Caribbean north of Colombia

Objectives: To estimate the prevalence of protozoan and helminth infections in a rural town of the Caribbean coast of Colombia and to identify potential risk factors. Methods: The study was conducted in Santa Catalina, a town and municipality located in the Bolívar during 2014. Parasitological analyses were done using 0.85% saline solution and lugol staining. A questionnaire was applied to participants in order to identify possible risk factors for parasite infections. Results: Mean age of sample population (N = 685) was 29.8 SD 622.46 and 68% were females. There is no sewage access in this town. Most of them were infected by any protozoan species (80%) or soil-transmitted helminthes (71%). The most common protozoan found was Entamoeba coli (53%) followed by Giardia duodenalis (13%), Blastocistys hominis (4%) and E. histolytica 82%). Ascaris lumbricoides was the most prevalent helminth (63%) followed by Trichuris trichuria (36%), hookworms (2%), Taenia sp (2%) and Hymenolepys nana (2%). Frequency rates of protozoan and helminthic infections were significantly lower in those living in a house build made of bricks (versus wood or "bahereque") or with a floor material distinct from soil/earth. Drinking boiled water was associated only with lower rates of trichuriasis (aOR: 0.59 95%CI: 0.41-0.78), but not ascariasis. Almost half of of subjects (56%) reported to have received deworming treatment in the last year, but this was not associated with having any parasite infection. In a sub-group of 109 with available data, Ascaris infection was associated with lower hemoglobin levels (B=0.75, SE: 0.25, p = 0.003, adjusted by age and gender). Conclusions: The prevalence of protozoan and helminth infections in this town, representative of the rural area of the Caribbean coast of Colombia, is high. Indicators of poverty and lower hygienic conditions are positively associated with parasite infections