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

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.     

Selectivity nomographs for classical filters

Nomographs for determining the filter order of classical filters based on selectivity requirements are presented. The selectivities for a variety of standard classical filters are summarized in equation form and the general selectivity nomograph is constructed. The selectivity equations are then converted into nomograph form by applying the relationship between the transfer function and the response slope. Design examples are presented to demonstrate the usefulness of the selectivity nomographs. These nomographs can be used to gauge filter performance and combined with optimization techniques can yield superior classical filter designs.     

On the construction of transitional filter nomographs

The construction of nomographs for transitional classical filters is described. Gain functions of classical filters are related to filter requirements resulting in a formulation for the general gain nomograph. The transitional filters that are products of approximating polynomials are incorporated into the general gain nomograph resulting in transitional filter nomographs that are sums of the individual nomographs. Nomographs for transitional filters using alternative forms where poles are interpolated are also considered. The resulting nomographs allow for quick optimization of transitional filter frequency response in many cases. Design examples are submitted and discussed. The proposed transitional filter nomographs provide the engineer with increased insight into the selection of classical transitional filters with optimum frequency response.     

The prevalence and impact of child maltreatment and other types of victimization in the UK: Findings from a population survey of caregivers,children and young people and young adults

Objectives

To measure the prevalence of maltreatment and other types of victimization among children, young people, and young adults in the UK; to explore the risks of other types of victimization among maltreated children and young people at different ages; using standardized scores from self-report measures, to assess the emotional wellbeing of maltreated children, young people, and young adults taking into account other types of childhood victimization, different perpetrators, non-victimization adversities and variables known to influence mental health.

Methods

A random UK representative sample of 2,160 parents and caregivers, 2,275 children and young people, and 1,761 young adults completed computer-assisted self-interviews. Interviews included assessment of a wide range of childhood victimization experiences and measures of impact on mental health.

Results

2.5% of children aged under 11 years and 6% of young people aged 11–17 years had 1 or more experiences of physical, sexual, or emotional abuse, or neglect by a parent or caregiver in the past year, and 8.9% of children under 11 years, 21.9% of young people aged 11–17 years, and 24.5% of young adults had experienced this at least once during childhood. High rates of sexual victimization were also found; 7.2% of females aged 11–17 and 18.6% of females aged 18–24 reported childhood experiences of sexual victimization by any adult or peer that involved physical contact (from sexual touching to rape). Victimization experiences accumulated with age and overlapped. Children who experienced maltreatment from a parent or caregiver were more likely than those not maltreated to be exposed to other forms of victimization, to experience non-victimization adversity, a high level of polyvictimization, and to have higher levels of trauma symptoms.

Conclusions

The past year maltreatment rates for children under age 18 were 7–17 times greater than official rates of substantiated child maltreatment in the UK. Professionals working with children and young people in all settings should be alert to the overlapping and age-related differences in experiences of childhood victimization to better identify child maltreatment and prevent the accumulative impact of different victimizations upon children's mental health.     

La dificultad de enseñar el razonamiento proporcional

Resumen

En este artículo se da cuenta de un experimento en el que se enseñó a sujetos cuya edad oscilaba entre los catorce y los diecisiete años a resolver tareas lógico-formales de carácter proporcional (balanza y comparación de proporciones) vinculadas al grupo INRC. Se trataba de ver: 1° Si se produce el aprendizaje deseado y 2° si el sujeto transfiere lo aprendido a otras tareas vinculadas a la misma estructura formal (grupo INRC) y a otras distintas (retículo).

Los resultados muestran un moderado éxito, según el tratamiento dado, en el aprendizaje de la tarea enseñada, y, una escasa o nula transferencia a tareas de similar estructura lógico-formal a las utilizadas en el aprendizaje.     

A Comprehensive Review of Educational Technology on Objective Learning Outcomes in Academic Contexts

Educational Psychology Review - Rapid advances in technology during the last few decades have provided a multitude of new options for teaching and learning. Although technology is being widely...     

Collective uplift: the impact of a holistic development support program on black male former college athletes’ experiences and outcomes

The purpose of this study was to examine the impact of a holistic development support program at Division I historically White institution (HWI) on Black male former college athletes’ pre- and post-graduation experiences and outcomes. Previous research has documented the myriad of challenges facing Black male college athletes at Division I HWIs including exposure to exploitive athletic sub-cultures, stigmatizing campus climates, and a general lack of support for their psychosocial, personal, and professional development. In response to these disconcerting trends, culturally relevant support programs have been created to address the unique needs of this sub-group. This qualitative case study involved 14 semi-structured individual interviews with seven Black male former college athletes who participated in a culturally relevant holistic development (CRHD) support program. Using the strategic responsiveness to interest convergence (SRIC) theory and the excellence beyond athletics (EBA) framework, key findings revealed participants’ involvement resulted in a range of personal and professional benefits both during and after college. Implications for policies and practices are discussed.     

La influencia del estilo cognitivo «Dependencia-Independencia de campo» en la resolución de dos problemas de física

Resumen

Este artículo trata de la influencia que tiene, en la actuación formal de los adolescentes, el estilo cognitivo. En este caso, el estilo cognitivo estudiado es la “Dependencia-Independencia de campo”, y las pruebas formales utilizadas son dos problemas de física en los que está implicado el esquema de control de variables. Los resultados obtenidos avalan la hipótesis de que, en este tipo de tareas, son los sujetos dependientes de campo los que tienen mayores dificultades para actualizar su competencia formal debido, fundamentalmente, a la dificultad que presentan para disociar unos factores de otros, sobre todo cuando éstos se ofrecen perceptivamente muy ligados.     

El aprendizaje de la estrategia de comparación de proporciones

Resumen

Este artículo versa sobre las dificultades que tienen los adolescentes para comprender la relación proporcional cuantitativa necesaria para resolver tareas de comparación de proporciones. Se comprueba, no obstante, que es posible, mediante determinadas sesiones de aprendizaje, propiciar en los adolescentes la adquisición plena del esquema operacional formal de la proporción.