Date of birth and the incidence of acute ischemic stroke in Hungary

INTRODUCTION

The effect of the date of birth on the incidence of cardiovascular disease was confirmed in earlier studies. We aimed to determine whether the season of birth may be associated with a higher incidence of stroke in later life by analyzing thrombolysis numbers according over a ten-year period in Hungary.

PATIENTS AND METHODS

We analyzed daily thrombolysis numbers between 2007 and 2016 according to the patients' date of birth based on seasons. The correlation between cumulative thrombolysis numbers between 2007 and 2016 per month and birth numbers per month based on data of the 1949 census were also examined.

RESULTS

Our results indicate that being born in the spring and summer in the northern hemisphere may be associated with a higher frequency of ischemic stroke necessitating thrombolytic treatment. This equates to a higher risk when conception and early pregnancy occur in the summer and autumn months.

CONCLUSIONS

This, however, cannot be defined as a causal relationship if we consider the number of live births in 1949, as both measures change similarly during the year, as indicated by the strong positive correlation between thrombolysis frequency according to date of birth between 2007 and 2016 and the number of births in the 1949 census by month.

Handedness and Relative Age in International Elite Interactive Individual Sports Revisited

Relative age effects (RAE) describe the unintended side effect of annual age grouping such that athletes born close to a specific cutoff date are more likely to be associated with attaining higher performance status than athletes born later. One factor suggested to override the RAE is handedness. Given the left-handers' rarity and their proposed performance advantage in interactive sports, left-handedness may be associated with a lower likelihood of suffering from selection inequalities like RAE in those sports compared with right-handedness. Here, in a two-study approach, we tested that hypothesis by examining male and female athletes from various interactive individual sports sampled over a 10-year period from 2007 to 2016. Study 1 investigated distributions of birth and handedness of senior athletes listed in the top 200 of year-end world rankings in table tennis, tennis, squash, and fencing (épée, foil, and saber). Study 2 followed a similar design but focused on junior athletes in the fencing disciplines and tennis. Unlike the above prediction, in both studies, birth distribution was not found to be reliably associated with handedness in any of the sports or disciplines considered. Left-handers were consistently overrepresented in épée, foil, and table tennis, occasionally in saber and tennis, and not at all in squash. Birth frequencies decreased from quartile Q1 (January to March) to Q4 in almost any sporting domain at the junior level, whereas such trend was rarely found at the senior level. In conclusion, while providing novel insight on the role handedness may play at the junior level, our findings do not support the hypothesis that left-handedness helps override birth-related inequalities in high sporting achievement in elite interactive individual sports.

A survey of some aspects of birthday celebration

BACKGROUND

The tradition of celebrating the day of birth of an individual is thought to have existed since the ancient times. Depending on the culture, religious beliefs, and the geographic location, occasions for ritual performance differ greatly. The aim of this pilot study was to investigate how students in Lithuania evaluate the importance of their birthday.

MATERIALS AND METHODS

An "Invitation to Remember Your Birthday" questionnaire was created by the authors to collect the responses for evaluation. The questionnaire consisted of 15 questions divided into four parts. It assessed how and what the respondents felt on their annual birthday, about the organization of the celebration, gift-receiving, and the value of the ritual.

RESULTS

A total of 309 medical students of Vilnius University completed the survey (n = 146 year 4, n = 163 year 5). The results suggested that the birthday is an important individual occasion, which students tend to celebrate annually. The respondents tend to feel better and more loved on the day of their birthday.

CONCLUSIONS

Birthday is seen as an opportunity to spend time with friends and family, have a break from daily responsibilities, and receive attention from people around them. Birthday celebration of medical students is affected by their social and cultural context. The findings of this study may be relevant for future studies when searching for age- and culture-appropriate ways to use birthday celebration as possible means of improving mental health. The current data can be used for longitudinal and cross-cultural comparisons.

An approach of estimating individual growth curves for young thoroughbred horses based on their birthdays

We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods.