排序方式: 共有16条查询结果,搜索用时 15 毫秒
1.
Alida Frankline Hasiniaina Ute Radespiel Sharon E. Kessler Mamy Rina Evasoa Solofonirina Rasoloharijaona Blanchard Randrianambinina Elke Zimmermann Sabine Schmidt Marina Scheumann 《Ecology and evolution》2020,10(8):3784-3797
Acoustic phenotypic variation is of major importance for speciation and the evolution of species diversity. Whereas selective and stochastic forces shaping the acoustic divergence of signaling systems are well studied in insects, frogs, and birds, knowledge on the processes driving acoustic phenotypic evolution in mammals is limited. We quantified the acoustic variation of a call type exchanged during agonistic encounters across eight distinct species of the smallest‐bodied nocturnal primate radiation, the Malagasy mouse lemurs. The species live in two different habitats (dry forest vs. humid forest), differ in geographic distance to each other, and belong to four distinct phylogenetic clades within the genus. Genetically defined species were discriminated reliably on the phenotypic level based on their acoustic distinctiveness in a discriminant function analysis. Acoustic variation was explained by genetic distance, whereas differences in morphology, forest type, or geographic distance had no effect. The strong impact of genetics was supported by a correlation between acoustic and genetic distance and the high agreement in branching pattern between the acoustic and molecular phylogenetic trees. In sum, stochastic factors such as genetic drift best explained acoustic diversification in a social communication call of mouse lemurs. 相似文献
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Erick Francisco Rakotoniriana Mamy Rafamantanana Denis Randriamampionona Christian Rabemanantsoa Suzanne Urveg-Ratsimamanga Mondher El Jaziri Françoise Munaut Anne-Marie Corbisier Joëlle Quetin-Leclercq Stéphane Declerck 《Antonie van Leeuwenhoek》2013,103(1):121-133
Thirty-one endophytic bacteria isolated from healthy leaves of Centella asiatica were screened in vitro for their ability to reduce the growth rate and disease incidence of Colletotrichum higginsianum, a causal agent of anthracnose. Isolates of Cohnella sp., Paenibacillus sp. and Pantoea sp. significantly stimulated the growth rate of C. higginsianum MUCL 44942, while isolates of Achromobacter sp., Acinetobacter sp., Microbacterium sp., Klebsiella sp. and Pseudomonas putida had no influence on this plant pathogen. By contrast, Bacillus subtilis BCA31 and Pseudomonas fluorescens BCA08 caused a marked inhibition of C. higginsianum MUCL 44942 growth by 46 and 82 %, respectively. Cell-free culture filtrates of B. subtilis BCA31 and P. fluorescens BCA08 were found to contain antifungal compounds against C. higginsianum MUCL 44942. Inoculation assays on in vitro-cultured plants of C. asiatica showed that foliar application of B. subtilis BCA31, three days before inoculation with C. higginsianum MUCL 44942, significantly reduced incidence and severity of the disease. The role of endophytic bacteria in maintaining the apparent inactivity of C. higginsianum MUCL 44942 in C. asiatica grown in the wild is discussed. 相似文献
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Steffens Travis S. Ramsay Malcolm S. Andriatsitohaina Bertrand Cosby Alexandria E. Lehman Shawn M. Rakotondravony Romule Razafitsalama Mamy Teixeira Helena Radespiel Ute 《International journal of primatology》2022,43(4):636-656
International Journal of Primatology - It is important to understand how sympatric congeners can co-occur within the same landscapes to better understand niche differentiation and how each species... 相似文献
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Eklou-Lawson Mamy Bernard Françoise Neveux Nathalie Chaumontet Catherine Bos Cécile Davila-Gay Anne-Marie Tomé Daniel Cynober Luc Blachier François 《Amino acids》2009,37(4):751-760
The highest ammonia concentration in the body is found in the colon lumen and although there is evidence that this metabolite
can be absorbed through the colonic epithelium, there is little information on the capacity of the colonic mucosa to transfer
and metabolize this compound. In the present study, we used a model of conscious pig with a canula implanted into the proximal
colon to inject endoluminally increasing amounts of ammonium chloride and to measure during 5 h the kinetics of ammonia and
amino acid concentration changes in the portal and arterial blood. By injecting as a single dose from 1 to 5 g ammonia into
the colonic lumen, a dose-related increase in ammonia concentration in the portal blood was recorded. Ammonia concentration
remained unchanged in the arterial blood except for the highest dose tested, i.e. 5 g which thus apparently exceeds the hepatic
ureagenesis capacity. By calculating the apparent net ammonia absorption, it was determined that the pig colonic epithelium
has the capacity to absorb 4 g ammonia. Ammonia absorption through the colonic epithelium was concomitant with increase of
l-glutamine and l-arginine concentrations in the portal blood. This coincided with the expression of both glutamate dehydrogenase and glutamine
synthetase in isolated colonic epithelial cells. Since l-glutamine and l-arginine are known to represent activators for liver ureagenesis, we propose that increased portal concentrations of these
amino acids following increased ammonia colonic luminal concentration represent a metabolic link between colon mucosa and
liver urea biosynthesis. 相似文献
6.
Dominik Schüßler Marina B. Blanco Nicola K. Guthrie Gabriele M. Sgarlata Melanie Dammhahn Refaly Ernest Mamy Rina Evasoa Alida Hasiniaina Daniel Hending Fabien Jan Barbara le Pors Alex Miller Gillian Olivieri Ando N. Rakotonanahary Solofomalala Jacques Rakotondranary Romule Rakotondravony Tantely Ralantoharijaona Veronarindra Ramananjato Blanchard Randrianambinina Nancia N. Raoelinjanakolona Emilienne Rasoazanabary Rodin M. Rasoloarison David W. Rasolofoson Solofonirina Rasoloharijaona Emmanuel Rasolondraibe Sam Hyde Roberts Helena Teixeira Tobias van Elst Steig E. Johnson Jörg U. Ganzhorn Lounès Chikhi Peter M. Kappeler Edward E. Louis Jr. Jordi Salmona Ute Radespiel 《American journal of physical anthropology》2024,183(1):60-78
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Soanandrasana Rahelinirina Jean‐Marc Duplantier Mamy Ratsimba Jocelyn Ratovonjato Olga Ramilijaona Yves Papillon Lila Rahalison 《African Journal of Ecology》2010,48(3):662-666
The black rat is the main plague reservoir in rural foci in Madagascar, inside the villages as well as in the cultivated areas around. We have evaluated the potentialities of mass‐marking of rats, using baits containing Rhodamine B (RB) in order to get a tool to study the movements of rats and to understand the spread of plague. Laboratory experiments demonstrated that: (i) rats were more attracted by the rodent granules and peanut butter; (ii) incorporation of RB in baits did not reduce their appetence; (iii) RB lasted for 60 days in rat vibrissae and 180 days in rat hairs; and (iv) consumption of baits during a week was under the lethal dose. Field tests have been realized comparatively among 24 highland villages where plague is endemic, in different contexts: baits inside houses or around the village, baits with and without RB, rats captured 1, 2 and 3 months after the marking. No negative effect of the RB on population dynamics of rats or fleas on them was observed. The effectiveness of the marking was comparable between males and females. This technique of collective marking appears very valuable for monitoring rat movements in plague foci. 相似文献
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Background
Relapse among abstinent drug users is normal. Several factors are related to relapse, but it remains unclear what individuals’ actual life circumstances are during periods of abstinence, and how these circumstances facilitate or prevent relapse.Objective
To illuminate drug users’ experiences during abstinence periods and explore the real-life catalysts and inhibitors contributing to drug use relapse.Method
Qualitative in-depth interviews were conducted with 20 drug users recruited from a compulsory isolated drug rehabilitation center in Changsha. The interviews were guided by open-ended questions on individuals’ experiences in drug use initiation, getting addicted, treatment history, social environment, abstinence, and relapse. Participants were also encouraged to share their own stories. Interviews were digitally recorded and fully transcribed. The data of 18 participants who reported abstinence experiences before admission were included in the analyses. The data were analyzed using a thematic analysis with inductive hand coding to derive themes.Results
Most drug users were able to successfully abstain from drugs. During abstinence, their lives were congested with challenges, such as adverse socioeconomic conditions, poor family/social support, interpersonal conflicts, and stigma and discrimination, all of which kept them excluded from mainstream society. Furthermore, the police’s system of ID card registration, which identifies individuals as drug users, worsened already grave situations. Relapse triggers reported by the participants focused mainly on negative feelings, interpersonal conflicts, and stressful events. Craving was experienced but not perceived as a relapse trigger by most participants.Conclusions
This study of in-depth interview with drug users found evidence of situations and environments they live during abstinence appear rather disadvantaged, making it extremely difficult for them to remain abstinent. Comprehensive programs on relapse prevention that acknowledge these disadvantages are implicated. 相似文献10.
Gaidet N Caron A Cappelle J Cumming GS Balança G Hammoumi S Cattoli G Abolnik C de Almeida RS Gil P Fereidouni SR Grosbois V Tran A Mundava J Fofana B El Mamy AB Ndlovu M Mondain-Monval JY Triplet P Hagemeijer W Karesh WB Newman SH Dodman T 《Proceedings. Biological sciences / The Royal Society》2012,279(1731):1131-1141
Despite considerable effort for surveillance of wild birds for avian influenza viruses (AIVs), empirical investigations of ecological drivers of AIV prevalence in wild birds are still scarce. Here we used a continental-scale dataset, collected in tropical wetlands of 15 African countries, to test the relative roles of a range of ecological factors on patterns of AIV prevalence in wildfowl. Seasonal and geographical variations in prevalence were positively related to the local density of the wildfowl community and to the wintering period of Eurasian migratory birds in Africa. The predominant influence of wildfowl density with no influence of climatic conditions suggests, in contrast to temperate regions, a predominant role for inter-individual transmission rather than transmission via long-lived virus persisting in the environment. Higher prevalences were found in Anas species than in non-Anas species even when we account for differences in their foraging behaviour (primarily dabbling or not) or their geographical origin (Eurasian or Afro-tropical), suggesting the existence of intrinsic differences between wildfowl taxonomic groups in receptivity to infection. Birds were found infected as often in oropharyngeal as in cloacal samples, but rarely for both types of sample concurrently, indicating that both respiratory and digestive tracts may be important for AIV replication. 相似文献