Perceived health problems in swimmers according to the chemical treatment of water in swimming pools     

Álvaro Fernández-Luna  Pablo Burillo  José Luis Felipe  Julio del Corral  Jorge García-Unanue  Leonor Gallardo 《European Journal of Sport Science》2016,16(2):256-265

The objective of this study was to determine which chemical treatment used for disinfecting water in indoor swimming pools had the least impact on users' perceptions of health problems, and which generated the greatest satisfaction with the quality of the water. A survey on satisfaction and perceived health problems was given to 1001 users at 20 indoor swimming pools which used different water treatment methods [chlorine, bromine, ozone, ultraviolet lamps (UV) and salt electrolysis]. The findings suggest that there is a greater probability of perceived health problems, such as eye and skin irritation, respiratory problems and skin dryness, in swimming pools treated with chlorine than in swimming pools using other chemical treatment methods. Pools treated with bromine have similar, although slightly better, results. Other factors, such as age, gender, time of day of use (morning and afternoon) and type of user (competitive and recreational), can also affect the probability of suffering health problems. For all of the above, using combined treatment methods as ozone and UV, or salt electrolysis produces a lower probability of perceived health problems and greater satisfaction.  相似文献   

Editorial     

Julio Grao  & José-Giné Mora 《European Journal of Education》2000,35(1):1-5

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Red pigment production by Penicillium purpurogenum GH2 is influenced by pH and temperature     

Méndez A  Pérez C  Montañéz JC  Martínez G  Aguilar CN 《Journal of Zhejiang University. Science. B》2011,12(12):961-968

The combined effects of pH and temperature on red pigment production and fungal morphology were evaluated in a submerged culture of Penicillium purpurogenum GH2, using Czapek-Dox media with d-xylose as a carbon source. An experimental design with a factorial fix was used: three pH values (5, 7, and 9) and two temperature levels (24 and 34 °C) were evaluated. The highest production of red pigment (2.46 g/L) was reached with a pH value of 5 and a temperature of 24 °C. Biomass and red pigment production were not directly associated. This study demonstrates that P. purpurogenum GH2 produces a pigment of potential interest to the food industry. It also shows the feasibility of producing and obtaining natural water-soluble pigments for potential use in food industries. A strong combined effect (p<0.05) of pH and temperature was associated with maximal red pigment production (2.46 g/L).  相似文献   

Editorial     

Julio González Bello 《International Journal for Educational and Vocational Guidance》2015,15(3):191-192

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The world of work between the personal and the collective: a demand for social justice and guidance for Latin America     

Julio Gonzalez Bello  Omaira Chacón 《International Journal for Educational and Vocational Guidance》2015,15(3):237-246

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The academic writing process in Spanish universities: perceptions of students and faculty / El proceso de escritura académica en la universidad española: percepciones de estudiantes y profesores     

Javier Marín  Sonia López  Julio Roca-De-Larios 《Cultura y Educación》2015,27(3):504-533

Abstract

This paper is intended as an exploration of university faculty and students’ perceptions of a number of dimensions involved in the written composition of academic texts. We analysed the responses to scale 3 in the European Writing Survey (EUWRIT) (in its Spanish version: Encuesta Europea sobre la Escritura Académica, EEEA) by a group of social science and humanities students (n = 1,030) and faculty (n = 230) from nine Spanish universities. We then examined the similarities and differences in their perceptions and established a factorial structure of the different dimensions underlying the writing process. The data indicate that both groups concur in the value assigned to both changing ideas in the course of the composition process (although this process seems to be understood differently by each group) and the revision and feedback processes. The students, however, claim to be involved in more planning and previous reading activities than the teachers perceive them to be. The significance of these results for a process-oriented perspective in academic writing is discussed.  相似文献   

Teachers' digital competence to assist students with functional diversity: Identification of factors through logistic regression methods     

Julio Cabero-Almenara  Francisco D. Guillén-Gámez  Julio Ruiz-Palmero  Antonio Palacios-Rodríguez 《British journal of educational technology : journal of the Council for Educational Technology》2022,53(1):41-57

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Flocking motion in swarms with limited sensing radius and heterogeneous input constraints     

Eber Jafet Ávila-Martínez  Juan Gonzalo Barajas-Ramírez 《Journal of The Franklin Institute》2021,358(4):2346-2366

This paper addresses the flocking motion problem for swarms of agents with two restrictions: limited communication/detection ranges and different input constraints. In this problem, the distance between pairs of agents determines if a communication/detection link exists among them, while each agent has a different control action bound. We use the notion of proximity graph to model communication/detection between agents and provide distributed controllers designed for leaderless and leader-followers flocking motion scenarios. Our proposed designs preserve the connectivity of the proximity graph while the control effort satisfies the bound of each particular agent. Unlike previous results, our protocols take advantage of the group’s input heterogeneity to use agents with a greater capacity to compensate for neighbors that are less capable of meeting the group’s requirements. Additionally, our designs are based only on local state errors and are robust to non-modeled edge failures. To illustrate the effectiveness of our proposal, we use numerical simulations of different flocking scenarios.  相似文献   

Separation and enrichment of sodium-motile bacteria using cost-effective microfluidics     

Jyoti P. Gurung  Moein Navvab Kashani  Sanaz Agarwal  Gonzalo Peralta  Murat Gel  Matthew A. B. Baker 《Biomicrofluidics》2021,15(3)

Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems.  相似文献   

A comparison of time-motion performance between age groups in judo matches     

Miarka B  Panissa VL  Julio UF  Del Vecchio FB  Calmet M  Franchini E 《Journal of sports sciences》2012,30(9):899-905

The aim of this study was to compare time-motion indicators during judo matches performed by athletes from different age groups. The following age groups were analysed: Pre-Juvenile (13-14 years, n = 522), Juvenile (15-16 years, n = 353); Junior (19 years, n = 349) and Senior (>20 years, n = 587). The time-motion indicators included: Total Combat Time, Standing Combat Time, Displacement Without Contact, Gripping Time, Groundwork Combat Time and Pause Time. Analysis of variance (ANOVA) one-way and the Tukey test, as well as the Kruskal-Wallis test and Mann-Whitney (for non-parametric data), were conducted, using P < 0.05 as significance level. The results showed that all analysed groups obtained a median of 7 (first quantile - 3, third quantile - 12) sequences of combat/pause cycles. In total time of combat, the result was: for Total Combat Time, Standing Combat Time and Gripping Time: Pre-Juvenile and Senior were significantly longer than Juvenile and Junior. Considering Displacement Without Contact, Junior was significantly longer than all other age groups. For Groundwork Combat Time, Senior was significantly longer than all other age groups and Pre-Juvenile was longer than Junior. These results can be used to improve the physiological performance in intermittent practices, as well as technical-tactical training during judo sessions.  相似文献