Minor Illnesses,Temperament, and Toddler Social Functioning

Research Findings: Minor illnesses, such as upper respiratory infections, stomachaches, and fevers, have been associated with children's decreased activity and increased irritability. This multi-method investigation of 110 day care–attending children examined whether experience with recurrent, minor illnesses and negative emotionality worked together to predict young children's social functioning. Minor illness experience was assessed via weekly health screenings conducted by nurses. Toddlers' negative emotionality and social behavior were assessed using mothers' and fathers' reports. The two dimensions of negative emotionality and minor illness experience operated in different ways to predict children's functioning. Toddlers rated as more temperamentally angry displayed less social competence, especially when they also experienced high proportions of minor illness. Temperamentally fearful children exhibited more externalizing problems when they experienced a higher frequency of illness, whereas fearfulness was not associated with externalizing problems for children who were not frequently ill. Practice or Policy: Children's frequent experience with minor illnesses combined with negative emotionality appears to place toddlers at a heightened risk for exhibiting behavior problems. These findings have implications for child and family well-being as well as interactions with child care providers and peers within child care settings. Interventions could be developed to target “at risk” children.     

‘Some kind of weird,evil experiment’: student perceptions of peer assessment

This paper explores the attitudes and perceptions of three cohorts of Australian humanities and social science undergraduate students towards peer assessment. It seeks to gain a deeper understanding of local dissatisfaction with peer assessment through an in‐depth analysis of students’ contributions to focus group discussions. Responding to education theorists’ claims that peer and other forms of innovative assessment empower students, the paper concentrates on themes of power evident within students’ narratives. The interpretive framework coheres around four interrelated conceptions of power: sovereign, epistemological, disciplinary and structural. Students were found to support the notion of peer assessment as a formative exercise, yet were highly critical of it as a summative practice. Significantly, some of the students’ dissatisfaction stemmed from broader changes across the higher education sector more generally. The paper draws attention to the need for this to be taken into account when considering assessment as a technology of power and empowerment.     

Preschool and Children's Outcomes in Elementary School: Have Patterns Changed Nationwide Between 1998 and 2010?

This study employs data from both kindergarten cohorts of the Early Childhood Longitudinal Study (n ~ 12,450 in 1998; n ~ 11,000 in 2010) to assess whether associations between preschool participation and children's academic and behavioral outcomes—both at school entry (M_age = 5.6 years in both cohorts) and through third grade—have changed over time. Findings are strikingly similar across these two, nationally representative, U.S. cohorts: preschool is positively associated with academic outcomes and negatively associated with behavioral outcomes both at school entry and as children progress through school. Heterogeneity is documented with respect to child and preschool characteristics. However, there is no evidence that associations between preschool and medium-term child outcomes differ by elementary school characteristics.     

A low-cost 3D printed microfluidic bioreactor and imaging chamber for live-organoid imaging

Organoids are biological systems grown in vitro and are observed to self-organize into 3D cellular tissues of specific organs. Brain organoids have emerged as valuable models for the study of human brain development in health and disease. Researchers are now in need of improved culturing and imaging tools to capture the in vitro dynamics of development processes in the brain. Here, we describe the design of a microfluidic chip and bioreactor, to enable in situ tracking and imaging of brain organoids on-chip. The low-cost 3D printed microfluidic bioreactor supports organoid growth and provides an optimal imaging chamber for live-organoid imaging, with drug delivery support. This fully isolated design of a live-cell imaging and culturing platform enables long-term live-imaging of the intact live brain organoids as it grows. We can thus analyze their self-organization in a controlled environment with high temporal and spatial resolution.     

冲向大海

夏天,是人们每年生命中最充盈着热力的季节,每到炎热的夏季我们总会由衷地盼望海边之旅。晴朗的天空、蔚蓝的海水、金黄的沙滩,还有迎面而来的海浪声,夏日里的海洋就是如此迷人,让人向往。记得日剧《沙滩小子》中运动员广海和白领海都因为不同的原因来到了海边,却在这里重新找到了生活的真谛。海边情怀是如此的温暖而真挚,本期我们特别奉献一组适用于海边的设计师家居作品,让我们一起冲向大海！     

The calibration and application of an individual scrummaging ergometer

Although the characteristic morphology of rugby forwards playing different positions in the rugby scrum has been well documented, a complete picture of the force characteristics that different players produce has not been evaluated. This is especially true for the movement of the centre of pressure (CoP) elicited during scrummaging in a forward direction. An individual scrummaging ergometer was therefore developed to measure the CoP of an individual scrum action using conventional torque calculations. Calibration of the measurement system revealed measured force errors within 16.6 N of the actual force and errors of less than 3.96 mm for CoP location determination. Thirty-nine club level rugby union players (22 front rows, 11 locks and six back rows) scrummed against the ergometer on an outdoor rugby field. Differences between the three groups were tested using one-way ANOVAs. The maximum force for different players was 2253.6 ± 649.0 N over the entire subject group. There were no differences in the individual compressive force between the groups [front rows: 2404.0 ± 650.3 N; locks: 2185.6 ± 568.9 N; back rows: 1826.9 ± 670.2 N (p = 0.143)]. Individually, front rows started at a higher position than back rows (p = 0.009) and were at a higher vertical position than locks when producing maximum force (p = 0.028). Front rows had lower variation in the CoP (p = 0.044) and less movement to achieve their maximum force (p = 0.020) than locks. Front rows moved less overall than back rows (p = 0.028) during the scrum trial. The design and application of the individual scrum ergometer showed with good limits of agreement that differences in force magnitude and CoP exist within scrummaging players. Practically, the application of this ergometer may assist in the individual optimisation of scrummaging performance.     

The effect of acute caffeine ingestion on upper body anaerobic exercise and cognitive performance

Abstract

The current study examined the effect of acute caffeine ingestion on mean and peak power production during upper body Wingate test (WANT) performance, rating of perceived exertion, readiness to invest effort and cognitive performance. Using a double-blind design, 12 males undertook upper body WANTs, following ingestion of caffeine (5?mg*kg^?1) or placebo. Pre-substance ingestion, 60?mins post substance ingestion and post exercise participants completed measures of readiness to invest physical and mental effort and cognitive performance. Peak power was significantly higher (P?=?.026), fatigue index greater (P?=?.02) and rating of perceived exertion lower (P?=?.025) in the presence of caffeine. Readiness to invest physical effort was also higher (P?=?.016) in the caffeine condition irrespective of time point (pre, 60?mins post ingestion and post exercise). Response accuracy for incongruent trials on the Flanker task was superior in the presence of caffeine (P?=?.006). There was a significant substance?×?time interaction for response speed in both congruent and incongruent conditions (both P?=?.001) whereby response speeds were faster at 60?mins post ingestion and post exercise in the caffeine condition, compared to placebo. This is the first study to examine the effects of caffeine ingestion on this modality of exercise and suggests that caffeine ingestion significantly enhances peak power, readiness to invest physical effort, and cognitive performance during WANT performance.     

Acute kinematic and kinetic adaptations to wearable resistance during vertical jumping

One variation of vertical jump (VJ) training is resisted or weighted jump training, where wearable resistance (WR) enables jumping to be overloaded in a movement specific manner. A two-way analysis of variance with Bonferroni post hoc contrasts was used to determine the acute changes in VJ performance with differing load magnitudes and load placements. Kinematic and kinetic data were quantified using a force plate and contact mat. Twenty sport active subjects (age: 27.8?±?3.8 years; body mass (BM): 70.2?±?12.2?kg; height: 1.74?±?0.78?m) volunteered to participate in the study. Subjects performed the counter movement jump (CMJ), drop jump (DJ) and pogo jump (PJ) wearing no resistance, 3% or 6% BM affixed to the upper or lower body. The main finding in terms of the landing phase was that the effect of WR was non-significant (P?>?.05) on peak ground reaction force. With regard to the propulsive phase the main findings were that for both the CMJ and DJ, WR resulted in a significant (P?<?.05) decrease in jump height (CMJ: ?12% to ?17%, DJ: ?10% to ?14%); relative peak power (CMJ: ?8% to ?17%, DJ: ?7% to ?10%); and peak velocity (CMJ: ?4% to ?7%, DJ: ?3% to ?8%); while PJ reactive strength index was significantly reduced (?15% to ?21%) with all WR conditions. Consideration should be given to the inclusion of WR in sports where VJ’s are important components as it may provide a novel movement specific training stimulus.

Highlights

• WR of 3 or 6 % BM provided a means to overload the subjects in this study resulting in decreased propulsive power and velocity that lead to a reduced jump height and landing force.

• Specific strength exercises that closely mimic sporting performance are more likely to optimise transference, therefore WR with light loads of 3–6% body mass (BM)appear a suitable tool for movement specific overload training and maximising transference to sporting performance.

• Practitioners can safely load their athletes with upper or lower body WR of 3–6% BM without fear of overloading the athletesover and above the landing forces they are typically accustomed too.

• As a training stimulus it would seem the WR loading provides adequate overload and athletes should focus on velocity of movement to improve power output and jump height i.e. take-off velocity.