Four semen traits: volume (VOL), concentration (CON), progressive motility of spermatozoa (MOT), and abnormal spermatozoa (ABN) provide complementary information on boar fertility. Assessment of the impact of selection for semen traits is hindered by limited information on economic parameters. Objectives of this study were to estimate economic values for semen traits and to evaluate the genetic...

BACKGROUND Autism spectrum disorders (ASD) are persistent and lifelong conditions. Despite this, almost all twin studies focus on childhood. This twin study investigated the stability of autistic traits from childhood to early adulthood and explored the degree to which any stability could be explained by genetic or environmental factors. METHODS Parents of over 2500 twin pairs completed quest...

Determining which underlying traits contribute to differences in whole-animal performance can be difficult when many traits differ between individuals with high and low capacities. We have previously found that migratory (anadromous marine) and non-migratory (stream-resident) threespine stickleback (Gasterosteus aculeatus) populations have genetically based differences in prolonged swimming per...

This study was conducted at the grasscutter section of the University of Education, Winneba, Ghana, to estimate effects of non-genetic factors on growth traits. Data consisted of records of 502 kids born from 136 does and 40 sires from 2006 to 2010. Feed intake increased (P<0.01) with increasing parity and years, whilst feed efficiency declined (P<0.01) with years. Animals consumed less (P<0.01...

Rheumatoid arthritis (RA) is a complex, chronic inflammatory disease implicated to have several plausible candidate loci; however, these may not account for all the genetic variations underlying RA. Common disorders are hypothesized to be highly complex with interaction among genes and other risk factors playing a major role in the disease process. This complexity is further magnified because s...

In many animal species, males have more than one secondary sexual character. Apart from theoretical considerations about the evolution of multiple traits, there are almost no empirical studies on female mate choice decisions based on combinations of traits as opposed to decisions based on single traits. Because three-spined sticklebacks are exceptionally well suited to be tested with computer a...

VII-VIII List of abbreviations XIV List of tables XVI List of figures XVIII List of appendices XXVI 1 2 2.1 2.1.1 2.1.1.1 2.1.1.2 2.1.1.3 2.1.1.4 2.1.1.5 2.1.1.6 2.1.1.7 2.1.2 2.1.2.1 2.1.2.2 2.2 2.2.1 2.2.2 2.3 2.4 2.4.1 2.4.1.1 2.4.1.2 2.4.2 2.4.3 Introduction Literature review Boar reproductivity Boar sperm quality traits Appearance of semen Sperm concentration Sperm motility Semen volume Pl...

There is considerable debate about the assessment of psychopathic traits in adolescence due in part to questions regarding the stability of traits. We investigated the 6-month stability of psychopathic traits in a sample of 83 male adolescent offenders using an augmented protocol for the Psychopathy Checklist: Youth Version and the self-report Antisocial Process Screening Device. Findings sugge...

We examined several determinants of interjudge agreement on personality traits. The findings, which were cross-validated in two samples, suggest that agreement is a function of four factors: which Big Five content domain the trait represents, how observable relevant behaviors are, how evaluative the trait is, and whether the self is one of the judges. Agreement was highest for traits related to...

This study explored genetic variation and co-variation in multiple functional plant traits. Our goal was to characterize selection, heritabilities and genetic correlations among different types of traits to gain insight into the evolutionary ecology of plant populations and their interactions with insect herbivores. In a field experiment, we detected significant heritable variation for each of ...