University of Fribourg

About: University of Fribourg is a education organization based out in Fribourg, Freiburg, Switzerland. It is known for research contribution in the topics: Population & Context (language use). The organization has 6040 authors who have published 14975 publications receiving 542500 citations. The organization is also known as: UNIFR & Universität Freiburg.

A fitness cost of learning ability in Drosophila melanogaster

Abstract: Maintenance of substantial genetic variation for learning ability in many animal populations suggests that learning ability has fitness costs, but there is little empirical evidence for them. In this paper, we demonstrate an evolutionary trade-off between learning ability and competitive ability in Drosophila melanogaster. We show that the evolution of an improved learning ability in replicated experimental fly populations has been consistently associated with a decline of larval competitive ability, compared with replicated control populations. The competitive ability was not affected by crossing of the replicate populations within each selection regime, excluding differential inbreeding as a potential confounding factor. Our results provide evidence for a constitutive fitness cost of learning ability, i.e. one that is paid irrespective of whether or not the learning ability is actually used.

Invasive alien predator causes rapid declines of native European ladybirds

Abstract: Aim Invasive alien species (IAS) are recognized as major drivers of biodiversity loss, but few causal relationships between IAS and species declines have been documented. In this study, we compare the distribution (Belgium and Britain) and abundance (Belgium, Britain and Switzerland) of formerly common and widespread native ladybirds before and after the arrival of Harmonia axyridis, a globally rapidly expanding IAS

Ectopic fat storage in heart, blood vessels and kidneys in the pathogenesis of cardiovascular diseases

Abstract: In humans and most animal models, the development of obesity leads not only to increased fat depots in classical adipose tissue locations but also to significant lipid deposits within and around other tissues and organs, a phenomenon known as ectopic fat storage The purpose of this review is to explore the possible locations of ectopic fat in key target-organs of cardiovascular control (heart, blood vessels and kidneys) and to propose how ectopic fat storage can play a role in the pathogenesis of cardiovascular diseases associated with obesity In animals fed a high-fat diet, cardiac fat depots within and around the heart impair both systolic and diastolic functions, and may in the long-term promote heart failure Accumulation of fat around blood vessels (perivascular fat) may affect vascular function in a paracrine manner, as perivascular fat cells secrete vascular relaxing factors, proatherogenic cytokines and smooth muscle cell growth factors Furthermore, high amounts of perivascular fat could mechanically contribute to the increased vascular stiffness seen in obesity Finally, accumulation of fat in the renal sinus may limit the outflow of blood and lymph from the kidney, which would alter intrarenal physical forces and promote sodium reabsorption and arterial hypertension Taken together, ectopic fat storage in key target-organs of cardiovascular control may impair their functions, contributing to the increased prevalence of cardiovascular diseases in obese subjects

Stress, sex, and satisfaction in marriage

Abstract: Using data from 198 couples, this study examines whether associations between stress occurring outside of the dyad and key indicators of relationship functioning are mediated by stress arising within the dyad. Findings suggest that relationship satisfaction and sexual activity are governed by hassles and problems experienced within the dyad that are in turn related to stress arising outside the dyad. Associations between external stress and relationship functioning are stronger for daily hassles than for critical life events. Higher levels of daily stress predicted less sexual activity for maritally dissatisfied women and more sexual activity for maritally dissatisfied men. Self-reports of stress covaried with self-reported indexes of satisfaction and sexuality, suggesting that contextual influences are broadly influential in intimate relationships.