Erythropoietin concentration and arterial haemoglobin saturation with supramaximal exercise.

The aim of this study was to determine if the hypoxaemic stimulus generated by intense exercise results in the physiological response of increased erythropoietin production. Twenty athletes exercised for 3 min at 109 +/- 2.8% (mean +/- s) maximal oxygen consumption. Estimated oxyhaemoglobin saturation was measured by reflective probe pulse oximetry (Nellcor N200) and was validated against arterial oxyhaemoglobin saturation by CO-oximetry in eight athletes. Serum erythropoietin concentrations-as measured using the INCSTAR Epo-Trac radioimmunoassay-increased significantly by 28 +/- 9% at 24 h post-exercise in 11 participants, who also had an arterial oxyhaemoglobin saturation < or = 91% (P < 0.05). Decreased ferritin levels and increased reticulocyte counts were observed at 96 h post-exercise. However, no significant changes in erythropoietin levels were observed in nine non-desaturating athletes and eight non-exercise controls. Good agreement was shown between arterial oxyhaemoglobin saturation and percent estimated oxyhaemoglobin saturation (limits of agreement = -3.9 to 3.7%). In conclusion, short supramaximal exercise can induce both hypoxaemia and increased erythropoietin levels in well-trained individuals. The decline of arterial hypoxaemia levels below 91% during exercise appears to be necessary for the exercise-induced elevation of serum erythropoietin levels. Furthermore, reflective probe pulse oximetry was found to be a valid predictor of percent arterial oxyhaemoglobin saturation during supramaximal exercise when percent estimated oxyhaemoglobin saturation > or = 86%.     

Longitudinal Stability of the Leadership Scale for Sports

This study was designed to examine the role of foot type, height, leg length, and range of motion (ROM) measurements on excursion distances while performing the Star Excursion Balance Test (SEBT), a test of dynamic postural control. Participants (n = 30) performed 3 trials of the SEBT in each of the 8 directions while balancing on the right and left legs. No statistically significant relations were found between foot type or ROM measurements and excursion distances with the SEBT. Significant correlations were revealed between height and excursion distance and leg length and excursion distance with leg length having the stronger correlation. Using raw excursion measures, males were found to have significantly greater excursion distances than females; however, after normalizing excursion distances to leg length, there were no significant differences related to gender. In conclusion, when using the SEBT for experimental or clinical purposes, participants' excursion distances should be normalized to leg length to allow for a more accurate comparison of performance among participants.     

Mothers’ Implicit and Explicit Attitudes and Attributions in Relation to Self-Reported Parenting Behavior

Objective. Parenting behavior is presumed to be related to the thoughts about child behavior that parents report in a controlled and explicit manner and to more implicit parent cognitions that occur outside of conscious awareness and are less accessible to verbal report. Design. We examined mothers’ attitudes toward their children as correlates of self-reported parenting behavior. We used a combination of a self-report questionnaire and a reaction-time method (the Implicit Association Test) to assess explicit and implicit attitudes, respectively. We also assessed mothers’ implicit and explicit attributions for child misbehavior in relation to parenting, using a questionnaire measure of attributions completed under high-cognitive load (implicit attributions) or under low-cognitive load (explicit attributions). Mothers of 124, 6- to 10-year-olds (52% male) participated. Results. Attitudes assessed by self-report questionnaire and the Implicit Association Test were uniquely associated with negative parenting. The cognitive load manipulation moderated associations between attributions and parenting, such that child-blaming attributions were inversely associated with positive parenting only under conditions of high-cognitive load. Conclusions. Compared to traditional self-report questionnaires, methods such as the Implicit Association Test or cognitive load manipulations may more effectively assess implicit parent cognitions.     

An Innovative Course Featuring Action Research Integrated with Unifying Science Themes

In this article, we describe an innovative capstone course for preservice K-8 teachers integrating action research and a unifying theme in science (AAAS in Science for all Americans. Oxford University Press, New York, 1989; NRC in National science education standards. National Academy Press, Washington, DC, 1996). The goals of the capstone course are to increase student knowledge of the unifying theme, improve written communication skills, and introduce students to educational research. We provide evidence that each of these goals is met. Student growth in theme knowledge is demonstrated through concept maps, questionnaires, and previously reported assessments. Improved writing ability is demonstrated using the spelling and grammar checking feature of Microsoft Word. The analysis of action research reports demonstrates that students are able to connect their action research project results to previous research.     

The influence of an afternoon nap on the endurance performance of trained runners

The effectiveness of a nap as a recovery strategy for endurance exercise is unknown and therefore the present study investigated the effect of napping on endurance exercise performance. Eleven trained male runners completed this randomised crossover study. On two occasions, runners completed treadmill running for 30?min at 75% ?O_2max in the morning, returning that evening to run for 20?min at 60% ?O_2max, and then to exhaustion at 90% ?O_2max. On one trial, runners had an afternoon nap approximately 90?min before the evening exercise (NAP) whilst on the other, runners did not (CON). All runners napped (20?±?10?min), but time to exhaustion (TTE) was not improved in all runners (NAP 596?±?148?s vs. CON 589?±?216?s, P?=?.83). Runners that improved TTE after the nap slept less at night than those that did not improve TTE (night-time sleep 6.4?±?0.7?h vs. 7.5?±?0.4?h, P?r^{2 ?} =??0.76, P?=?.001). In runners that improved TTE, ratings of perceived exertion (RPE) were lower during the TTE on NAP than CON compared to runners that did not improve (?0.4?±?0.6 vs. 0?±?0, P?=?.05). Reduced exercising sense of effort (RPE) may account for the improved TTE after the nap. In conclusion, a short afternoon nap improves endurance performance in runners that obtain less than 7?h night-time sleep.     

Dielectrophoretic differentiation of mouse ovarian surface epithelial cells, macrophages, and fibroblasts using contactless dielectrophoresis

Ovarian cancer is the leading cause of death from gynecological malignancies in women. The primary challenge is the detection of the cancer at an early stage, since this drastically increases the survival rate. In this study we investigated the dielectrophoretic responses of progressive stages of mouse ovarian surface epithelial (MOSE) cells, as well as mouse fibroblast and macrophage cell lines, utilizing contactless dielectrophoresis (cDEP). cDEP is a relatively new cell manipulation technique that has addressed some of the challenges of conventional dielectrophoretic methods. To evaluate our microfluidic device performance, we computationally studied the effects of altering various geometrical parameters, such as the size and arrangement of insulating structures, on dielectrophoretic and drag forces. We found that the trapping voltage of MOSE cells increases as the cells progress from a non-tumorigenic, benign cell to a tumorigenic, malignant phenotype. Additionally, all MOSE cells display unique behavior compared to fibroblasts and macrophages, representing normal and inflammatory cells found in the peritoneal fluid. Based on these findings, we predict that cDEP can be utilized for isolation of ovarian cancer cells from peritoneal fluid as an early cancer detection tool.     

Behavioral synchronization and affiliation: Dogs exhibit human-like skills

Behavioral synchronization is evolutionary adaptive, fostering social cohesion. In humans, affiliation between partners is associated with a high level of behavioral synchronization; people show increased affiliation towards people who synchronize with them. Surprisingly, until recently, little was known about these phenomena at an interspecific level, which is, however, essential to better understand the respective roles of evolution and ontogeny. After presenting why dog–human dyads are a relevant biological model to study this field of social cognition, we review the recent findings about dog–human behavioral synchronization. We summarize recently published findings on behavioral synchronization and affiliation between dogs and humans. We also review results showing that genetic selection modulates behavioral synchronization propensity in dogs, emphasizing the role of genetic selection on dog’s social behaviors towards humans. Finally, we discuss the possible evolutionary influences and proximate mechanisms of this phenomenon. We conclude that, as in humans, behavioral synchronization acts as a social glue between dogs and humans. After dogs’ ability to use human-directional cues or to produce referential cues towards humans, we evidenced a new human-like social process in the dog, at the interspecfic level with humans.