Menstrual status and thermoregulatory responses of active adolescents during exercise in a cold environment

This study examined the interactions between the reproductive status and the thermoregulatory responses during exercise in the cold in girls involved in competitive sports. Four girls with established menstrual cycles comprised the eumenorrheic menarcheal group (EM) and 5 non-menstruating girls comprised the pre-menarcheal group (PM). During the first visit maximal oxygen consumption, height, weight and percent body fat (%BF) were measured. The second visit involved: a determination of metabolic rate in thermoneutrality (21°C) involving 10-min rest and 20-min cycling (30% of VCL max), and a cold stress test (5°C, 40% humidity, <0.3 m/s air velocity) involving 20-min rest and 40-min cycling (30% of VCL max.). Subjects in the EM group were tested twice in the chamber during the follicular and luteal phases. Pre-menarcheal subjects were found to have significantly (p<0.05) lower core temperatures during the final stages of cold exposure. Overall, body fat was not significantly correlated with core temperature in the cold, however there was a significant surface-to-mass ratio difference between the groups. While in the follicular phase, EM girls had a higher core temperature during cold exposure. Therefore, reproductive hormonal status seems to be an important factor in terms of cold tolerance in females during adolescence.

Perceptions of some teachers about the similarities and/or differences in teaching online versus in a classroom environment /

The introduction of computer and communications technology, and particularly the internet, into education has opened up some new possibilities for teaching and learning. Courses designed and delivered in an online environment offer the possibility of highly interactive and individually focussed teaching and learning experiences. However, online courses also present new challenges for both teachers and students. A qualitative study was conducted to explore teachers' perceptions about the similarities and differences in teaching in the online and face-to-face (F2F) environments. Focus group discussions were held with 5 teachers; 2 teachers were interviewed in depth. The participants, 3 female and 2 male, were full-time teachers from a large College of Applied Arts & Technology in southern Ontario. Each of them had over 10 years of F2F teaching experience and each had been involved in the development and teaching of at least one online course. i - -; The study focussed on how teaching in the online environment compares with teaching in the F2F environment, what roles teachers and students adopt in each setting, what learning communities mean online and F2F and how they are developed, and how institutional policies, procedures, and infrastructure affect teaching and learning F2F and online. This study was emic in nature, that is the teachers' words determine the themes identified throughout the study. The factors identified as affecting teaching in an online environment included teacher issues such as course design, motivation to teach online, teaching style, role, characteristics or skills, and strategies. Student issues as perceived by the teachers included learning styles, role, and characteristics or skills. As well, technology issues such as a reliable infrastructure, clear role and responsibilities for maintaining the infrastructure, support, and multimedia capability affected teaching online. Finally, administrative policies and procedures, including teacher selection and training, registration and scheduling procedures, intellectual property and workload policies, and the development and communication of a comprehensive strategic plan were found to impact on teaching online. The teachers shared some of the benefits they perceived about teaching online as well as some of the challenges they had faced and challenges they perceived students had faced online. Overall, the teachers feh that there were more similarities than differences in teaching between the two environments, with the main differences being the change from F2F verbal interactions involving body language to online written interactions without body language cues, and the fundamental reliance on technology in the online environment. These findings support previous research in online teaching and learning, and add teachers' perspectives on the factors that stay the same and the factors that change when moving from a F2F environment to an online environment.

Interactions of diploid embryonal carcinoma cells and normal cell mass cells with 2.5 day mouse embryos following aggregation

Spontaneous teratocarcinomas are ovarian or testicular tumors which have their origins in germ cells. The tumors contain a disorganized array of benign differentiated cells as well as an undifferentiated population of malignant stem cells, the embryonal carcinoma or EC cells. These pluripotent stem cells in tissue culture share many properties with the transient pluripotent cells of the early embryo, and might therefore serve as models for the investigation of developmental events ill vitro. The property of EC cells of prime interest in this study is an in vivo phenomenon. Certain EC cell lines are known to be regulated ill vivo and to differentiate normally in association with normal embryonic cells, resulting in chimeric mice. These mice have two genetically distinct cell populations, one of which is derived from the originally malignant EC cells. This has usually been accomplished by injection of the EC cells into the Day 3 blastocyst. In this study, the interactions between earlier stage embryos and EC cells have been tested by aggregating clumps of EC cells with Day 2 embryos. The few previous aggregation studies produced a high degree of abnormality in chimeric embryos, but the EC cells employed had known chromosomal abnormalities. In this study, two diploid EC cell lines (P19 and Pi0) were aggregated with 2.5 day mouse embryos, and were found to behave quite differently in the embryonic environment. P19 containing aggregates generally resorbed early, and the few embryos recovered at midgestation were normal and non-chimeric. Pi0 containing aggregates survived in high numbers to midgestation, and the Pi0 cells were very successful in colonizing the embryo. All these embryos were chimeric, and the contribution by the EC cells to each chimera was very high. However, these heavily chimeric embryos were all abnormal. Blastocyst injection had previously produced some abnormal embryos with high Pl0 contributions in addition to the live born mice, which had lower EC contributions. This study now adds more support to the hypothesis that high EC contributions may be incompatible with normal development. The possibility that the abnormalities were due to the mixing of temporally asynchronous embryonic cell types in the aggregates was tested by aggregating normal pluripotent cells taken from 3.5 day embryos with 2.5 day embryos. Early embryo loss was very high, and histological studies showed that the majority of these embryos died by 6.5 days development. Some embryos escaped this early death such that some healthy chimeras were recovered, in contrast to recovery of abnormal chimeric embryos following Pl0-morula aggregations, and non-chimeric embryos following P19-morula aggregations. This somewhat surprising adverse effect on development following aggregation of normal cell types suggests that there are developmental difficulties associated with the mixing of asynchronous cell types in aggregates. However, the greater magnitude of the adverse effects when the aggregates contained tumor derived cells suggests that EC cells should not be considered the complete equivalent of the pluripotent cells of the early embryo.

The Family Game: A Parent Education Intervention to Increase Positive Parent-Child Interactions in Parents with Learning Difficulties

Children of parents with learning difficulties (LD) are at risk for a variety of developmental problems including behavioural and psychiatric disorders. However, there are no empirically supported programs to prevent behavioural and psychiatric problems in these children. The purpose of the study was to test the effectiveness of a parenting intervention designed to teach parents with learning difficulties positive child behaviour management strategies. A multiple baseline across skills design was used with two parents, who were taught three skills: 1) clear instructions, 2) recognition of compliance and 3) correction of noncompliance. Training scores improved on each skill and maintained at a 1-month follow-up. Scores on generalization cards were high and showed maintenance, but improvements in parenting skills in the naturalistic environment were low at posttest and follow-up. Increases were seen in child compliance at posttest and 1-month follow-up. Results of pre-post social validity measures were also generally positive.