16 research outputs found
Going That Extra Mile: Individuals Travel Further to Maintain Face-to-Face Contact with Highly Related Kin than with Less Related Kin
The theory of inclusive fitness has transformed our understanding of cooperation and altruism. However, the proximate psychological underpinnings of altruism are less well understood, and it has been argued that emotional closeness mediates the relationship between genetic relatedness and altruism. In this study, we use a real-life costly behaviour (travel time) to dissociate the effects of genetic relatedness from emotional closeness. Participants travelled further to see more closely related kin, as compared to more distantly related kin. For distantly related kin, the level of emotional closeness mediated this relationship - when emotional closeness was controlled for, there was no effect of genetic relatedness on travel time. However, participants were willing to travel further to visit parents, children and siblings as compared to more distantly related kin, even when emotional closeness was controlled for. This suggests that the mediating effect of emotional closeness on altruism varies with levels of genetic relatednes
Anti-fibrotic effects of curcumin and some of its analogues in the heart.
Cardiac fibrosis stems from the changes in the expression of fibrotic genes in cardiac fibroblasts (CFs) in response to the tissue damage induced by various cardiovascular diseases (CVDs) leading to their transformation into active myofibroblasts, which produce high amounts of extracellular matrix (ECM) proteins leading, in turn, to excessive deposition of ECM in cardiac tissue. The excessive accumulation of ECM elements causes heart stiffness, tissue scarring, electrical conduction disruption and finally cardiac dysfunction and heart failure. Curcumin (Cur; also known as diferuloylmethane) is a polyphenol compound extracted from rhizomes of Curcuma longa with an influence on an extensive spectrum of biological phenomena including cell proliferation, differentiation, inflammation, pathogenesis, chemoprevention, apoptosis, angiogenesis and cardiac pathological changes. Cumulative evidence has suggested a beneficial role for Cur in improving disrupted cardiac function developed by cardiac fibrosis by establishing a balance between degradation and synthesis of ECM components. There are various molecular mechanisms contributing to the development of cardiac fibrosis. We presented a review of Cur effects on cardiac fibrosis and the discovered underlying mechanisms by them Cur interact to establish its cardio-protective effects
Gene flow is maintained by polyandry and male dispersal in the army ant Eciton burchellii
Worker drift and egg dumping by queens in wild Bombus terrestris colonies
Wild bumblebee colonies are hard to find and often inaccessible, so there have been few studies of the genetic structure of bumblebees within natural colonies, and hence, it is not clear how frequently events such as worker reproduction, worker drift and queen usurpation take place. This study aimed to quantify the occurrence of natal-worker reproduction, worker drift and drifter reproduction within 14 wild colonies of Bombus terrestris in Central Scotland. Four unlinked microsatellites were used to identify patterns of relatedness of the colonies' adults and broods. In colonies with queens (queenright colonies), worker reproduction accounted for just 0.83 % of males, increasing to 12.11 % in queenless colonies. Four colonies contained a total of six workers which were not daughters of the queen, and were assumed to be drifters, and four male offspring of drifters. Drifting is clearly not common and results in few drifter offspring overall, although drifters produced approximately seven times more offspring per capita than workers that remained in their natal colony. Unexpectedly, two colonies contained clusters of sister workers and juvenile offspring that were not sisters to the rest of the adults or brood found in the colonies, demonstrating probable egg dumping by queens. A third colony contained a queen which was not a sister or daughter to the other bees in the colony. Although usurping of bumblebee colonies by queens in early season is well documented, this appears to be the first record of egg dumping, and it remains unclear whether it is being carried out by old queens or newly mated young queens
The role of visual and olfactory plant cues in aphid behaviour and the development of non-persistent virus management strategies
The review was part of M. L. Schroder’s PhD
thesis that was undertaken at the University of Pretoria (UP) in collaboration
with the Swedish University of Agricultural Sciences
(SLU).Non-persistent viruses are transmitted by aphids in short feeding probes
during the initial stages of aphid host plant selection behaviour. To control
the transmission of these viruses, farmers rely on pesticides and cultural
control practices, with varying success rates. As a result, there is a need for
novel management practices that are more robust and specific to reducing
aphid landing rates in crops. Aphid–plant–virus interactions involve a
number of behaviours and processes to ensure survival of the insect vector
and virus. So far, virus management tactics focused on reducing
immigrating aphids in crops have emphasized the manipulation of visual rather than olfactory stimuli. An improved understanding of the synergistic
or additive effects in which aphids use visual and olfactory stimuli to locate
host plants could be used to improve on current non-persistent virus
management tactics and develop novel strategies. The aim of this review is
to evaluate current understanding of aphid vector behaviour and the ways
that these behaviours have been exploited to develop management
strategies, and to identify areas of research needed to further improve virus
management.Potatoes South Africa
(PSA), the Technology and Human Resources for Industry Programme
(THRIPP), the National Research Foundation (NRF) and the
University of Pretoria.http://link.springer.com/journal/118292018-02-28hb2017Zoology and Entomolog