Preregistration in infant research—A primer

Preregistration, the act of specifying a research plan in advance, is becoming more common in scientific research. Infant researchers contend with unique problems that might make preregistration particularly challenging. Infants are a hard‐to‐reach population, usually yielding small sample sizes, they can only complete a limited number of trials, and they can be excluded based on hard‐to‐predict complications (e.g., parental interference, fussiness). In addition, as effects themselves potentially change with age and population, it is hard to calculate an a priori effect size. At the same time, these very factors make preregistration in infant studies a valuable tool. A priori examination of the planned study, including the hypotheses, sample size, and resulting statistical power, increases the credibility of single studies and adds value to the field. Preregistration might also improve explicit decision making to create better studies. We present an in‐depth discussion of the issues uniquely relevant to infant researchers, and ways to contend with them in preregistration and study planning. We provide recommendations to researchers interested in following current best practices.     

Double robust estimator in general treatment regimes based on Covariate-balancing

Double robust estimators have double the chance of being a consistent estimator of a causal effect in binary treatments cases. In this paper, we proposed an estimator of a causal effect for general treatment regimes based on covariate-balancing. Under parametrical situation, our estimator has double robustness.     

Inequality for equireplicated n-ary block designs with unequal block sizes

It is shown that certain inequalities known for binary, equireplicated, equiblock-sized block designs remain valid for equireplicated n-ary block designs with unequal block sizes. The approach used here is based on the spectral expansion of the C-matrix of the block design. The main theorems include some useful and combinatorially interesting results.     

Seasonal and weather-related behavioral effects among urban Aboriginal, urban non-Aboriginal, and remote Aboriginal participants in Canada

The influence of seasonal change and weather on mood, social activity, weight, food consumption, and sleep length was compared across urban Aboriginals (n = 43), urban non-Aboriginals (n = 49), and remote Aboriginals (n = 39) in Ontario, Canada. Such research is important since climate change may differentially shape the well-being of social groups. Behavioral items—including mood, social activity, weight, sleep, and food consumption—were measured using the Seasonal Pattern Assessment Questionnaire, and associations between these items and meteorological data were examined with bivariate and multivariate approaches. Weather variables had consistent, significant associations with behavior except within the remote Aboriginal group despite living in a more extreme climate. Lifestyle and adaptation may contribute to an increased weather tolerance among remote Aboriginal people, intriguing findings as cultures grapple with the implications of future climate change.     

Health expectancies in Japan: gender differences and policy implications for women

Based on prospective observation of elderly people in the community in Japan, we compared the time-course of development and progression of physical disability between women and men. Men experienced disability at a younger age and at a faster rate than did women. The duration of time spent with disability in women was twice as long as in men. Consequently, women consume about two-thirds of the total resources of formal caregiving services in Japan. Women in Japan are increasingly educated, postponing marriage to higher ages, and less likely to care for parents in the home. Given these changes in family structure and social norms, the capacity for informal family caregiving has decreased dramatically. A recently enacted national long-term care insurance system may further change the picture of caregiving.     

A simple evolutionary model of dormancy and dispersal in heterogeneous patches with special reference to phytophagous lady beetles: I. Stable environments

Summary A simple evolutionary model of dormancy and dispersal is presented with special reference to phytophagous lady beetles. In order to investigate spatially heterogeneous environments, we assume the simplest patch structure, that is, there are only two patches, main and sub. Environments are also assumed to be temporally constant. The main patch is superior to the sub patch, but density effect at the main patch is higher than at the sub patch. Optimal dormancy and dispersal are obtained at the same time by the method of evolutionarily stable strategy (ESS). In the univoltine life cycle, dormancy strategy vanishes because dormant individuals do not reproduce at all but suffer from a certain mortality rate during winter hibernation. In the bivoltine life cycle, the dormancy and dispersal rates constitute a trade-off: the rates change together with a negative correlation when the mortality rate during dispersal or during winter hibernation changes. When suitability of the main patch gradually deteriorates, the optimal strategy changes as follows: neither dormancy nor dispersal is adopted at the most suitable condition, the dispersal rate is increased without dormancy in the intermediate condition, and then the dormancy rate is increased with a constant dispersal rate. We discuss the field observation data of lady beetles in the light of results of our model.     

Fetal movement frequency and the effect of associated perinatal factors: Multicenter study

Background

Decreased fetal movements are associated with adverse perinatal outcomes, including stillbirth. Delayed maternal visits to a health care provider after perceiving decreased fetal movements are frequently observed in stillbirths. Informing pregnant women of the normal range of fetal movement frequency is essential in their earlier visits in order to prevent stillbirth.

Excessively delayed maternal reaction after their perception of decreased fetal movements in stillbirths: Population-based study in Japan

Background

Fetal movement is the most common method to evaluate fetal well-being. Furthermore, maternal perception of decreased fetal movements is associated with perinatal demise. Previously, we showed that perception of decreased fetal movements was the most common reason for mothers visiting the outpatient department among those who had stillbirths in our region. Further investigation of stillbirths with decreased fetal movements is essential to find a possible way of preventing stillbirth.