Search results for "pituus"
showing 10 items of 36 documents
Inbreeding reveals mode of past selection on male reproductive characters in Drosophila melanogaster
2013
Directional dominance is a prerequisite of inbreeding depression. Directionality arises when selection drives alleles that increase fitness to fixation and eliminates dominant deleterious alleles, while deleterious recessives are hidden from it and maintained at low frequencies. Traits under directional selection (i.e., fitness traits) are expected to show directional dominance and therefore an increased susceptibility to inbreeding depression. In contrast, traits under stabilizing selection or weakly linked to fitness are predicted to exhibit little-to-no inbreeding depression. Here, we quantify the extent of inbreeding depression in a range of male reproductive characters and then infer t…
Effects of photoperiod on life-history and thermal stress resistance traits across populations of Drosophila subobscura
2019
Introduction Organisms use environmental cues to match their phenotype with the future availability of resources and environmental conditions. Changes in the magnitude and frequency of environmental cues such as photoperiod and temperature along latitudes can be used by organisms to predict seasonal changes. While the role of temperature variation on the induction of plastic and seasonal responses is well established, the importance of photoperiod for predicting seasonal changes is less explored. Materials and methods Here we studied changes in life‐history and thermal stress resistance traits in Drosophila subobscura in response to variation in photoperiod (6:18, 12:12 and 18:6 light:dark …
Dissociating spatial and letter-based word length effects observed in readers’ eye movement patterns
2011
In previous eye movement research on word length effects, spatial width has been confounded with the number of letters. McDonald (2006) unconfounded these factors by rendering all words in sentences in constant spatial width. In the present study, the Arial font with proportional letter spacing was used for varying the number of letters while equating for spatial width, while the Courier font with monospaced letter spacing was used to measure the contribution of spatial width to the observed word length effect. Number of letters in words affected single fixation duration on target words, whereas words’ spatial width determined fixation locations in words and the probability of skipping a wo…
Birth weight and adult income : An examination of mediation through adult height and body mass
2021
This paper examines the causal links between early human endowments and socioeconomic outcomes in adulthood. We use a genotyped longitudinal survey (Cardiovascular Risk in Young Finns Study) that is linked to the administrative registers of Statistics Finland. We focus on the effect of birth weight on income via two anthropometric mediators: body mass index (BMI) and height in adulthood. We find that (i) the genetic instruments for birth weight, adult height, and adult BMI are statistically powerful; (ii) there is a robust total effect of birth weight on income for men but not for women; (iii) the total effect of birth weight on income for men is partly mediated via height but not via BMI; …
Early Life Influences on Hearing in Adulthood : a Systematic Review and Two-Step Individual Patient Data Meta-Analysis
2021
Objectives: Adverse prenatal and early childhood development may increase susceptibility of hearing loss in adulthood. The objective was to assess whether indices of early development are associated with adult-onset hearing loss in adults ≥18 years. Design: In a systematic review and meta-analysis, four electronic databases were searched for studies reporting associations between indices of early development (birth weight and adult height) and adult-onset hearing loss in adults ≥18 years. We screened studies, extracted data, and assessed risk of bias. Authors were contacted to provide adjusted odds ratios from a logistic regression model for relationships between birth weight/adult height a…
The role of letters and syllables in typical and dysfluent reading in a transparent orthography
2012
The role of letters and syllables in typical and dysfluent 2nd grade reading in Finnish, a transparent orthography, was assessed by lexical decision and naming tasks. Typical readers did not show reliable word length effects in lexical decision, suggesting establishment of parallel letter processing. However, there were small effects of word syllable structure in both tasks suggesting the presence of some sublexical processing also. Dysfluent readers showed large word length effects in both tasks indicating decoding at the letterphoneme level. When lexical access was required in a lexical decision task, dyslexics additionally chunked the letters into syllables. Response duration measure rev…
Dual-stage and dual-deficit? Word recognition processes during text reading across the reading fluency continuum
2021
AbstractCentral questions in the study of visual word recognition and developmental dyslexia are whether early lexical activation precedes and supports decoding (a dual-stage view) or not (dual-route view), and the locus of deficits in dysfluent reading. The dual-route view predicts early word frequency and length interaction, whereas the dual-stage view predicts word frequency effect to precede the interaction effect. These predictions were tested on eye movements data collected from (n = 152) children aged 9–10 among whom reading dysfluency was overrepresented. In line with the dual-stage view, the results revealed an early word frequency effect in first fixation duration followed by robu…
Sublexical effects on eye movements during repeated reading of words and pseudowords in Finnish
2011
The role of different orthographic units (letters, syllables, words) in reading of orthographically transparent Finnish language was studied by independently manipulating the number of letters (NoL) and syllables (NoS) in words and pseudowords and by recording eye movements during repeated reading aloud of these items. Fluent adult readers showed evidence for using larger orthographic units in (pseudo)word recoding, whereas dysfluent children seem to be stuck in a letter-based decoding strategy, as lexicality and item repetition decreased the NoL effect only among adult readers. The NoS manipulation produced weak repetition effects in both groups. However, dysfluent children showed evidence…
Infant and childhood growth and frailty in old age : the Helsinki Birth Cohort Study
2018
BackgroundEvidence from life course studies highlights the importance of infant and childhood growth as risk factors for adulthood chronic diseases.MethodsIn this sub-study of the Helsinki Birth Cohort Study, we studied 1078 individuals who had both information on body size from birth to 12 years of age and who were assessed for frailty according to the Fried criteria at the mean age of 71 years.ResultsGreater BMI gain between 2 and 11 years in boys was associated with frailty in old age (age-adjusted RRR 2.36, 95% CI 1.21, 4.63). No similar associations were observed in girls.ConclusionsMen who were frail in old age experienced accelerated BMI gain in childhood compared with those men who …
Diminishing benefits of urban living for children and adolescents’ growth and development
2023
Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being 1-6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5-19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a smal…