Search results for "POPULATIONS"
showing 10 items of 493 documents
Successive Invasion-Mediated Interspecific Hybridizations and Population Structure in the Endangered Cichlid Oreochromis mossambicus.
2013
Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genet…
Testosterone and oxidative stress: the oxidation handicap hypothesis
2007
Secondary sexual traits (SST) are usually thought to have evolved as honest signals of individual quality during mate choice. Honesty of SST is guaranteed by the cost of producing/maintaining them. In males, the expression of many SST is testosterone-dependent. The immunocompetence handicap hypothesis has been proposed as a possible mechanism ensuring honesty of SST on the basis that testosterone, in addition to its effect on sexual signals, also has an immunosuppressive effect. The immunocompetence handicap hypothesis has received mixed support. However, the cost of testosterone-based signalling is not limited to immunosuppression and might involve other physiological functions such as the…
State-dependent pairing behaviour in male Gammarus pulex (L.) (Crustacea, Amphipoda): effects of time left to moult and prior pairing status
2004
Because mating can be costly in terms of time and energy, an individual's propensity to engage in courtship and mating activities might be modulated by its physiological state. However, so far, state-dependent mate choice has received little attention The present study examined the effect of both prior pairing status and time left to the moult on the ability of male Gammarus pulex (Crustacea, Amphipoda) to enter in precopula with receptive females. In the lab, males that were freshly collected in precopula pairs in the field had a higher probability of re-pairing and were quicker to enter in precopula with receptive females compared to males of similar size that were freshly collected unpai…
Caution on the assessment of intestinal parasitic load in studying parasite-mediated sexual selection: the case of Blackbirds coccidiosis.
2009
6 pages; International audience; The parasite-mediated sexual selection (PMSS) theory has led to an increasing number of experimental studies essentially focussed on blood parasites. Currently, more research is being carried out on intestinal parasites in relationship to this theory. Before testing the theory with gastrointestinal parasites, it is important: (i) to determine an optimal research methodology to obtain an accurate assessment of parasite burden and (ii) to have information about life-history traits of the parasite to interpret data appropriately. In this study, we present data on oocyst output of Isosporaturdi in the faeces of blackbirds (Turdus merula) that illustrate the impo…
Deregulation of Notch1 pathway and circulating endothelial progenitor cell (EPC) number in patients with bicuspid aortic valve with and without ascen…
2018
AbstractBicuspid aortic valve (BAV) is frequently associated with the development of ascending aortic aneurysm, even if the underlying mechanisms remain to be clarified. Here, we investigated if a deregulation of Notch1 signaling pathway and endothelial progenitor cells (EPCs) number is associated with BAV disease and an early ascending aortic aneurysm (AAA) onset. For this purpose, 70 subjects with BAV (M/F 50/20; mean age: 58.8 ± 14.8 years) and 70 subjects with tricuspid aortic valve (TAV) (M/F 35/35; mean age: 69.1 ± 12.8 years) and AAA complicated or not, were included. Interestingly, patients with AAA showed a significant increase in circulating Notch1 levels and EPC number than subje…
Treatment of Venous Thromboembolism in Special Populations with Direct Oral Anticoagulants
2020
AbstractAs a result of the successful completion of their respective phase III studies compared with vitamin K antagonists (VKAs), four direct oral anticoagulants (DOACs) have been approved for the treatment and secondary prevention of venous thromboembolism (VTE). These DOACs—apixaban, dabigatran, edoxaban, and rivaroxaban—have subsequently seen a steady uptake among clinicians since their approval. Despite the suitability of DOACs for a broad range of patients, they are not appropriate in certain situations, whereas in others they require additional considerations such as dose reductions. Subanalyses of phase III trials and studies on specific VTE patient populations have been conducted t…
Effect of a Prebiotic Formulation on Frailty Syndrome
2016
Aging can result in major changes in the composition and metabolic activities of bacterial populations in the gastrointestinal system and result in impaired function of the immune system. We assessed the efficacy of prebiotic Darmocare Pre (R) (Bonusan Besloten Vennootschap (BV), Numansdorp, The Netherlands) to evaluate whether the regular intake of this product can improve frailty criteria, functional status and response of the immune system in elderly people affected by the frailty syndrome. The study was a placebo-controlled, randomized, double blind design in sixty older participants aged 65 and over. The prebiotic product was composed of a mixture of inulin plus fructooligosaccharides …
Disadvantaged neighborhoods and the spatial overlap of substantiated and unsubstantiated child maltreatment referrals
2019
Abstract Background Considerable debate exists on whether the substantiation decision is a reliable measure for rates of maltreatment. Studies have shown that risks among children victims of maltreatment versus children investigated but unsubstantiated are similar. Objective This paper aims to respond to two research questions: (1) Do most child maltreatment referrals, substantiated and unsubstantiated, come from the same neighborhoods? (2) Do substantiated and unsubstantiated referrals share the same neighborhood risk factors? Participants and settings We used geocoded data from substantiated (n = 1799) and unsubstantiated (n = 1638) child maltreatment referrals in Valencia, Spain (2004–20…
Massive migration from the steppe was a source for Indo-European languages in Europe
2015
We generated genome-wide data from 69 Europeans who lived between 8,000-3,000 years ago by enriching ancient DNA libraries for a target set of almost four hundred thousand polymorphisms. Enrichment of these positions decreases the sequencing required for genome-wide ancient DNA analysis by a median of around 250-fold, allowing us to study an order of magnitude more individuals than previous studies and to obtain new insights about the past. We show that the populations of western and far eastern Europe followed opposite trajectories between 8,000-5,000 years ago. At the beginning of the Neolithic period in Europe, ~8,000-7,000 years ago, closely related groups of early farmers appeared in G…
A computer-based Pinyin intervention for disadvantaged children in China: Effects on Pinyin skills, phonological awareness, and character reading.
2019
Pinyin is an alphabetic script that denotes pronunciations of Chinese characters. Studies have shown that Pinyin instruction enhances both phonological awareness (e.g., Shu et al., Developmental Science, 2008, 11, 171-181) and character reading (e.g., Lin et al., Psychological Science, 2010, 21, 1117-1122) in Chinese children. In the present study, we provided a 3-week Pinyin intervention with a computer-based Pinyin GraphoGame to disadvantaged migrant children with poor Pinyin skills. A total of 252 first graders who were children of migrant workers in a large Chinese city were assessed to identify poor Pinyin readers. Fifty-six 7-year-old children with poor Pinyin skills were selected and…