The Relative Age Effect in Minor Ice Hockey: Investigating the 'Underdog Effect'

Abstract The Relative Age Effect (RAE), defined as a skewed birth date distribution, has been identified as a known phenomenon in minor ice hockey. The purpose of this study was to investigate the relationship between the RAE, physical measurements, and skating ability/in-game performance in forty-four youth male ice hockey players competing in the same age cohort. Physical anthropometrics, grip strength, in-game performance and skating abilities were measured. An RAE was found in the sample (χ2(3, N = 44) = 12.18, p = 0.007). Players born in the first half of the age cohort had longer leg length (F(1,42) =4.49 , p = 0.04), larger body mass (F(1,42) = 3.90, p = 0.05), and stronger grip strength (F(1,42) = 7.58, p = 0.009). Performance scores were negatively associated with grip strength (r = -.443, p = 0.003). Findings suggest that adequate skill development can help relatively younger players overcome physical maturity disadvantages.

Relative age effect on the reaction time of soccer players under 13 years old

O efeito da idade relativa, que consiste na vantagem obtida pelo atleta nascido mais próximo ao início do ano de seleção, tem se mostrado uma variável importante para o processo de seleção de esportistas. Este estudo objetivou avaliar a influência da época de nascimento no tempo de reação de escolha de futebolistas presentes nas categorias de base (sub 13) de clubes profissionais futebol. Participaram 76 atletas com idade de 13,36 ± 0,45 anos. Os voluntários foram submetidos ao teste do TRE, e os resultados categorizados conforme o semestre de nascimento (S1 ou S2). Foi empregado o teste t para a comparação entre grupos, e análise de Correlação de Pearson para verificar a existência de associações entre as variáveis. Os resultados não indicaram diferenças entre os grupos no tempo de reação (r = 0,033 e p = 0,772) e no tempo de movimento (r = 0,0073 e p = 0,530). Concluiu-se que para essa população, a época de nascimento não influencia no desempenho dessa capacidade.

Relative Age Effect in Young Swiss Alpine Skiers From 2004 to 2011

PURPOSE To verify whether the relative age effects (RAEs) occur among young male and female Swiss alpine skiers of different age groups and performance levels. Additionally, the efficacy of normalizing performance in physical tests to height and body mass to attenuate RAEs eventually present was tested. METHODS The Swiss-Ski Power Test consists of anthropometric measures and physical tests for coordination and speed, endurance and strength and is used since 2004 to evaluate 11- to 19-years old Swiss competitive alpine skiers. We analysed the distribution of 6996 tests performed by 1438 male and 1031 female alpine skiers between 2004 and 2011 according to the athlete's relative age quartile (Q). Differences in anthropometric measures and performance in physical tests according to Q were assessed and the possibility of attenuating eventual RAEs on performance by normalization of results to height and body mass was tested. RESULTS RAEs were found among all female and male age groups, with no differences between age groups. While performance level did not affect RAE for male skiers, it influenced RAE among female skiers. RAEs also influenced results in all physical tests except upper limbs strength. Normalization of results to body mass attenuated most RAEs identified. CONCLUSION small RAEs are present among young Swiss competitive alpine skiers and should be taken into account in training and selection settings, avoiding the waste of possible future talents. When ranking junior athletes according to their performance in physical tests, normalization of results to body mass decreases the bias caused by RAEs.

Olika chans beroende på födelsemånad : En kvantitativ undersökning av relative age effect på svenska längdskidgymnasier

Syfte Syftet med studien var att undersöka om relative age effect förekommer på svenska längdskidgymnasier bland antagna elever och hur eventuell förekomst ser ut bland flickor och pojkar samt hur det ser ut vid Riksidrottsgymnasierna och de Nationell Idrottsutbildningarna. Metod För att besvara syftet har statistisk data analyserats med hjälp av ett Pearson Chi2-test. Analysen har skett genom att undersöka födelsemånad, kön och inriktning bland antagna elever vid svenska längdskidgymnasier mellan åren 2010-2015. Resultat Resultatet visar att det finns signifikanta bevis på att relative age effect förkommer på svenska längdskidgymnasier (p= <0,05). Vid uppdelning av respektive utbildningsinriktning kunde det endast konstateras förekomst av relative age effect vid Riksidrottsgymnasierna, vid uppdelning av kön går det inte att säkerställa en signifikant förekomst av relative age effect. Slutsatser Studiens resultat visar att det förekommer relative age effect på svenska längdskidgymnasier, dock varierar den mellan de analyserade undervariablerna. Tydligast förekommer relative age effect vid Riksidrottsgymnasierna, medan det vid Nationell Idottsutbildning, kunde det inte konstateras bevis för en signifikant överrepresentation av elever födda under första kvartalet. När flickor och pojkar analyserades separat kunde ingen relative age effect konstateras. Det behövs mer forskning inom området för att få en överblick av konsekvenserna av relative age effect på längdskidgymnasier men även konsekvenserna för svensk längdskidåkning i stort.

Host age effect and expression of cytoplasmic incompatibility in field populations of Wolbachia-superinfected Aedes albopictus

The Asian tiger mosquito, Aedes albopictus (Skuse), is a known vector of dengue in South America and Southeast Asia. It is naturally superinfected with two strains of Wolbachia endosymbiont that are able to induce cytoplasmic incompatibility (CI). In this paper, we report the strength of CI expression in crosses involving field-caught males. CI expression was found to be very strong in all crosses between field males and laboratory-reared uninfected or wAlbA infected young females. In addition, crossing experiments with laboratory colonies showed that aged super- infected males could express strong CI when mated with young uninfected or wAlbA infected females. These results provide additional evidence that the CI properties of Wolbachia infecting Aedes albopictus are well suited for applied strategies that seek to utilise Wolbachia for host population modification.

Growth of preterm low birth weight infants until 24 months corrected age: effect of maternal hypertension

Objective: To evaluate the growth pattern of low birth weight preterm infants born to hypertensive mothers, the occurrence of growth disorders, and risk factors for inadequate growth at 24 months of corrected age (CA).Methods: Cohort study of preterm low birth weight infants followed until 24 months CA, in a university hospital between January 2009 and December 2010. Inclusion criteria: gestational age < 37 weeks and birth weight of 1,500-2,499g. Exclusion criteria: multiple pregnancies, major congenital anomalies, and loss to follow up in the 2nd year of life. The following were evaluated: weight, length, and BMI. Outcomes: growth failure and risk of overweight at 0, 12, and 24 months CA. Student's t-test, Repeated measures ANOVA (RM-ANOVA), and multiple logistic regression were used.Results: A total of 80 preterm low birth weight infants born to hypertensive mothers and 101 born to normotensive mothers were studied. There was a higher risk of overweight in children of hypertensive mothers at 24 months; however, maternal hypertension was not a risk factor for inadequate growth. Logistic regression showed that being born small for gestational age and inadequate growth in the first 12 months of life were associated with poorer growth at 24 months.Conclusion: Preterm low birth weight born infants to hypertensive mothers have an increased risk of overweight at 24 months CA. Being born small for gestational age and inadequate growth in the 1st year of life are risk factors for growth disorders at 24 months CA. (C) 2014 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Age effect in generating mental images of buildings but not common objects

Imagining a familiar environment is different from imagining an environmental map and clinical evidence demonstrated the existence of double dissociations in brain-damaged patients due to the contents of mental images. Here, we assessed a large sample of young and old participants by considering their ability to generate different kinds of mental images, namely, buildings or common objects. As buildings are environmental stimuli that have an important role in human navigation, we expected that elderly participants would have greater difficulty in generating images of buildings than common objects. We found that young and older participants differed in generating both buildings and common objects. For young participants there were no differences between buildings and common objects, but older participants found easier to generate common objects than buildings. Buildings are a special type of visual stimuli because in urban environments they are commonly used as landmarks for navigational purposes. Considering that topographical orientation is one of the abilities mostly affected in normal and pathological aging, the present data throw some light on the impaired processes underlying human navigation.

Is the date of birth an advantage/ally to excel in handball?

The Relative Age Effect (RAE) has been analyzed in a population of Spanish international handball players (n=161) divided into four different levels: Senior, Junior, Juvenile and Promising Talents. The variables registered were quarter, half year and year of birth using the initial information of their date of birth. The data were collected from the Royal Spanish Handball Federation on-line data base. The statistical method used was the χ2 and the minimum level of significance was set at p<0.05. The total results on distribution by quarter show a significant difference (χ2= 21.68; p<0.01) with a greater frequency of players born in the first quarter (40.37%) compared to those born in the second (22.36%), third (16.15%) and fourth quarter (21.12%). The total results on the distribution of birth date by half year show a significant difference (χ2= 10.44; p<0.01) with a greater frequency of players born in the first half of the year (62.73%). With regard to the rate of births registered in an even numbered or odd numbered year there are significant differences when the rates for an even numbered year (64.60%) and an odd numbered year (35.40%) are compared with those of the general population (χ2= 13.72; p<0.001). Based on the data collected and analyzed it can be concluded that there is a RAE in the basic categories of the Spanish national men’s handball teams according to quarter, half year and year of birth (even or odd numbered), but there exists little knowledge about the causes and consequence which may be produced by, or derive from, this effect.

When “Where” is More Important Than “When”: Birthplace and Birthdate Effects On The Achievement Of Sporting Expertise

In this study, we assessed whether contextual factors related to where or when an athlete is born influence their likelihood of playing professional sport. The birthplace and birth month of all American players in the National Hockey League, National Basketball Association, Major League Baseball, and Professional Golfer's Association, and all Canadian players in the National Hockey League were collected from official websites. Monte Carlo simulations were used to verify if the birthplace of these professional athletes deviated in any systematic way from the official census population distribution, and chi-square analyses were conducted to determine whether the players' birth months were evenly distributed throughout the year. Results showed a birthplace bias towards smaller cities, with professional athletes being over-represented in cities of less than 500,000 and under-represented in cities of 500,000 and over. A birth month/relative age effect (in the form of a distinct bias towards elite athletes being relatively older than their peers) was found for hockey and baseball but not for basketball and golf. Comparative analyses suggested that contextual factors associated with place of birth contribute more influentially to the achievement of an elite level of sport performance than does relative age and that these factors are essentially independent in their influences on expertise development.

When "where'' is more important than "when": Birthplace and birthdate effects on the achievement of sporting expertise

In this study, we assessed whether contextual factors related to where or when an athlete is born influence their likelihood of playing professional sport. The birthplace and birth month of all American players in the National Hockey League, National Basketball Association, Major League Baseball, and Professional Golfer's Association, and all Canadian players in the National Hockey League were collected from official websites. Monte Carlo simulations were used to verify if the birthplace of these professional athletes deviated in any systematic way from the official census population distribution, and chi-square analyses were conducted to determine whether the players' birth months were evenly distributed throughout the year. Results showed a birthplace bias towards smaller cities, with professional athletes being over-represented in cities of less than 500,000 and under-represented in cities of 500,000 and over. A birth month/relative age effect (in the form of a distinct bias towards elite athletes being relatively older than their peers) was found for hockey and baseball but not for basketball and golf. Comparative analyses suggested that contextual factors associated with place of birth contribute more influentially to the achievement of an elite level of sport performance than does relative age and that these factors are essentially independent in their influences on expertise development.

Increased risk of cardiovascular disease (CVD) with age in HIV-positive men : a comparison of the D:A:D CVD risk equation and general population CVD risk equations

OBJECTIVES: The aim of the study was to statistically model the relative increased risk of cardiovascular disease (CVD) per year older in Data collection on Adverse events of anti-HIV Drugs (D:A:D) and to compare this with the relative increased risk of CVD per year older in general population risk equations. METHODS: We analysed three endpoints: myocardial infarction (MI), coronary heart disease (CHD: MI or invasive coronary procedure) and CVD (CHD or stroke). We fitted a number of parametric age effects, adjusting for known risk factors and antiretroviral therapy (ART) use. The best-fitting age effect was determined using the Akaike information criterion. We compared the ageing effect from D:A:D with that from the general population risk equations: the Framingham Heart Study, CUORE and ASSIGN risk scores. RESULTS: A total of 24 323 men were included in analyses. Crude MI, CHD and CVD event rates per 1000 person-years increased from 2.29, 3.11 and 3.65 in those aged 40-45 years to 6.53, 11.91 and 15.89 in those aged 60-65 years, respectively. The best-fitting models included inverse age for MI and age + age(2) for CHD and CVD. In D:A:D there was a slowly accelerating increased risk of CHD and CVD per year older, which appeared to be only modest yet was consistently raised compared with the risk in the general population. The relative risk of MI with age was not different between D:A:D and the general population. CONCLUSIONS: We found only limited evidence of accelerating increased risk of CVD with age in D:A:D compared with the general population. The absolute risk of CVD associated with HIV infection remains uncertain.