42,891 research outputs found
The case of rainforest stiletto snakes (genus Atractaspis) in southern Nigeria. Evidence of diverging foraging strategies in grossly sympatric snakes with homogeneous body architecture?
No full textwe report some data on the food habits of free-ranging Atractaspis in rainforest habitats of southern Nigeria, and suggest a discussion point that could serve as basis for investigating the evolution of Atractaspis species in homogenous habitats where they occur sympatrically
The ecological distribution of Causus (Viperidae) in Nigeria, with special reference to Causus resimus and Causus lichtensteini, two species rarely recorded from this country.
No full textNew data for snakes of the genus Causus Wagler 1830 (Viperidae) are
reported for Nigeria, with emphasis on their ecological distribution and biology.
Causus rhombeatus (Lichtenstein 1823) was never observed during our long-term
field study, and is probably a very rare species in Nigeria, confined to a small
area in the north-east of the country. We confirmed that Causus maculatus (Hallowell
1842) is widespread in Nigeria, inhabiting a wide variety of ecological
regions, from the rainforests of the south to the Sudanese savanna in the north.
It feeds on amphibians, mainly ranid frogs. Causus resimus (Peters 1862) was
reported to occur in Nigeria only on the basis of a few specimens without precise
locality. We found three vouchers with known locality of capture in the Zoological
Museum of Copenhagen, and we captured a few other specimens in the
field. Although probably rare (given the very few captures), this species has a
wide distribution in Nigeria, mainly in savannas and forest-derived savannas. It
feeds on toads. Causus lichtensteini (Jan 1859) was occasionally captured in the
swamp-forests of the Niger Delta (southern Nigeria), but seems to be absent
from other forested regions of the country. It is also an anuran-eate
Evolution of the G+C content frontier in the rat cytomegalovirus genome
No full textWithin the 230138 bp of the rat cytomegalovirus (RCMV) genome, the G+C content changes abruptly at position 142644, constituting a G+C content frontier. To the left of this point, overall G+C content is 69.2%, and to the right it is only 47.6%. A region of extremely low G+C content (33.8%) is found in the 5 kb immediately to the right of the frontier, in which there are no predicted coding sequences. To the right of position 147501, the G+C content rises and predicted coding sequences reappear. However, these genes are much shorter (average 848bp, 50% G+C) than those in the left two-thirds of the genome (average 1462bp, 70% G+C). Whole genome alignment of several viruses indicates that the initial ultra-low G+C region appeared in the common ancestor of the genera Cytomegalovirus and Muromegalovirus, and that the lowering of G+C in the right third has been a subsequent process in the lineage leading to RCMV. The left two-thirds of RCMV has stop codon occurrences at 67.5% of their expected level, based on a modified Markov chain model of stop codon distribution, and the corresponding figure for the right third is 78%. Therefore, despite heavy mutation pressure, selective constraint has operated in the right third of the RCMV genome to maintain a degree of gene length unusual for such low G+C sequences
Inter-seasonal and inter-habitat variations in the diet of the African fire skink, Lygosoma fernandi, from southern Nigeria
No full textThe inter-habitat and inter-seasonal variations in the taxonomic diet composition of the African fire skink, Lygosoma fernandi, one of the largest Scincidae of the Afrotropical regions, were studied by analysis of excrements collected from live individuals that were captured in some areas of the Niger Delta region, southern Nigeria. 22 prey types, mostly arthropods, were found in the diet of this species, with significant differences in prey composition between seasons. Isopoda and Coleoptera dominated in the dietary samples, with very few prey types exclusive of one habitat type and/or season (e. g. Formicidae in dry forest in both seasons and lizards in swamp forest in wet season). Overall, no difference between forest types and seasons was found as for diversity and evenness indices except for that prey diversity was higher in feces collected in the dry forest in dry season, whereas dominance and evenness did not show any significant variation across forest types
Bibliographie
No full textAbercrombie C. L., 1978 – Notes on West African crocodiles (Reptilia : Crocodilia). Journal of Herpetology, 12 : 260-262. Akani G. C., Angelici F. M., Politano E., 1998 – Bushmen and herpetofauna. Notes on amphibians and reptiles traded in bush-meat markets of local people in the Niger Delta (Port Harcourt, Rivers State, Nigeria). AnthropoZoologica, 27 : 21-26. Akani G. C., Luiselli L., 2000 – Some observations on diurnal activity patterns, habitat, and naturel history of Mabuya affinis (Scin..
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
A simple tool to make a long story short: Photographic Identification Method (PIM) using natural body marks
No full textPhotographic identification method (PIM) using natural body marks: A simple tool to make a long story short
No full textIndividual marking allows researchers to collect important data using Mark-recapture method. Photographic Identification Method (PIM) has obtained favorable opinions, being effective and less intrusive with respect to traditional marking procedures. Here, we developed and tested the efficacy of a software-aided PIM based on different characteristics, which act as natural marks. Target species were the northern spectacled salamander (Salamandrina perspicillata, Amphibia: Urodela) and the stag beetle (Lucanus cervus, Coleoptera: Lucanidae). We considered as natural mark the ventral pattern of S. perspicillata and, for the first time in L. cervus, the presence/number of small denticles on male mandibles. We selected 4 independent characteristics, each one with several states, for each species. We asked participants, with different degree of familiarity with the species, to identify recaptured individuals through manual PIM. To assess the advantages of the software, we compared the time spent by experts of the species to identify an individual through manual PIM and software-aided PIM. We further compared our semi-automated method with a fully automated one. The software efficiency was calculated by increasing the number of characteristics used to filter individuals from the database (from 1 to 4). The chosen characteristics proved their reliability for individual identification and can be used as natural marks. The proposed software-aided PIM shorten the identification time, does not led to mismatching errors and proved its efficacy regardless of the taxa/characteristic used. Thus, this tool can be consider a more practical alternative to conventional marking techniques, in particular for sensitive and threatened species that need quick and effective monitoring programs carried out with non-invasive samplin
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
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