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Equatorial Guinea (equatorial + guinea)
Selected AbstractsEQUATORIAL GUINEA: Reform PlanAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 6 2010Article first published online: 3 AUG 2010 No abstract is available for this article. [source] EQUATORIAL GUINEA: Shopping SpreeAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 11 2010Article first published online: 18 DEC 200 No abstract is available for this article. [source] EQUATORIAL GUINEA: Oil and Human RightsAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 7 2009Article first published online: 27 AUG 200 No abstract is available for this article. [source] EQUATORIAL GUINEA: Lofty AspirationsAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 3 2009Article first published online: 1 MAY 200 No abstract is available for this article. [source] CAMEROON,EQUATORIAL GUINEA: Border SealedAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 2 2009Article first published online: 7 APR 200 No abstract is available for this article. [source] An unusual distribution of the kdr gene among populations of Anopheles gambiae on the island of Bioko, Equatorial GuineaINSECT MOLECULAR BIOLOGY, Issue 6 2005L. J. Reimer Abstract In West Africa, Anopheles gambiae exists in discrete subpopulations known as the M and S molecular forms. Although these forms occur in sympatry, pyrethroid knock-down resistance (kdr) is strongly associated with the S molecular form. On the island of Bioko, Equatorial Guinea we found high frequencies of the kdr mutation in M form individuals (55.8%) and a complete absence of kdr in the S form. We also report the absence of the kdr allele in M and S specimens from the harbour town of Tiko in Cameroon, representing the nearest continental population to Bioko. The kdr allele had previously been reported as absent in populations of An. gambiae on Bioko. Contrary to earlier reports, sequencing of intron-1 of this sodium channel gene revealed no fixed differences between M form resistant and susceptible individuals. The mutation may have recently arisen independently in the M form on Bioko due to recent and intensive pyrethroid application. [source] Equatorial Guinea: Macroeconomic IndicatorsAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 6 2010Article first published online: 3 AUG 2010 No abstract is available for this article. [source] Equatorial Guinea,Spain: Oil Opens New Era in RelationsAFRICA RESEARCH BULLETIN: ECONOMIC, FINANCIAL AND TECHNICAL SERIES, Issue 7 2009Article first published online: 27 AUG 200 No abstract is available for this article. [source] The inselberg flora of Atlantic Central Africa.JOURNAL OF BIOGEOGRAPHY, Issue 4 2005Abstract Aims, To identify the relative contributions of environmental determinism, dispersal limitation and historical factors in the spatial structure of the floristic data of inselbergs at the local and regional scales, and to test if the extent of species spatial aggregation is related to dispersal abilities. Location, Rain forest inselbergs of Equatorial Guinea, northern Gabon and southern Cameroon (western central Africa). Methods, We use phytosociological relevés and herbarium collections obtained from 27 inselbergs using a stratified sampling scheme considering six plant formations. Data analysis focused on Rubiaceae, Orchidaceae, Melastomataceae, Poaceae, Commelinaceae, Acanthaceae, Begoniaceae and Pteridophytes. Data were investigated using ordination methods (detrended correspondence analysis, DCA; canonical correspondence analysis, CCA), Sřrensen's coefficient of similarity and spatial autocorrelation statistics. Comparisons were made at the local and regional scales using ordinations of life-form spectra and ordinations of species data. Results, At the local scale, the forest-inselberg ecotone is the main gradient structuring the floristic data. At the regional scale, this is still the main gradient in the ordination of life-form spectra, but other factors become predominant in analyses of species assemblages. CCA identified three environmental variables explaining a significant part of the variation in floristic data. Spatial autocorrelation analyses showed that both the flora and the environmental factors are spatially autocorrelated: the similarity of species compositions within plant formations decreasing approximately linearly with the logarithm of the spatial distance. The extent of species distribution was correlated with their a priori dispersal abilities as assessed by their diaspore types. Main conclusions, At a local scale, species composition is best explained by a continuous cline of edaphic conditions along the forest-inselberg ecotone, generating a wide array of ecological niches. At a regional scale, these ecological niches are occupied by different species depending on the available local species pool. These subregional species pools probably result from varying environmental conditions, dispersal limitation and the history of past vegetation changes due to climatic fluctuations. [source] Characterizing the phylogenetic structure of communities by an additive partitioning of phylogenetic diversityJOURNAL OF ECOLOGY, Issue 3 2007OLIVIER J. HARDY Summary 1Analysing the phylogenetic structure of natural communities may illuminate the processes governing the assembly and coexistence of species in ecological communities. 2Unifying previous works, we present a statistical framework to quantify the phylogenetic structure of communities in terms of average divergence time between pairs of individuals or species, sampled from different sites. This framework allows an additive partitioning of the phylogenetic signal into alpha (within-site) and beta (among-site) components, and is closely linked to Simpson diversity. It unifies the treatment of intraspecific (genetic) and interspecific diversity, leading to the definition of differentiation coefficients among community samples (e.g. IST, PST) analogous to classical population genetics coefficients expressing differentiation among populations (e.g. FST, NST). 3Two coefficients which express community differentiation among sites from species identity (IST) or species phylogeny (PST) require abundance data (number of individuals per species per site), and estimators that are unbiased with respect to sample size are given. Another coefficient (,ST) expresses the gain of the mean phylogenetic distance between species found in different sites compared with species found within sites, and requires only incidence data (presence/absence of each species in each site). 4We present tests based on phylogenetic tree randomizations to detect community phylogenetic clustering (PST > IST or ,ST > 0) or phylogenetic overdispersion (PST < IST or ,ST < 0). In addition, we propose a novel approach to detect phylogenetic clustering or overdispersion in different clades or at different evolutionary time depths using partial randomizations. 5IST, PST or ,ST can also be used as distances between community samples and regressed on ecological or geographical distances, allowing us to investigate the factors responsible for the phylogenetic signal and the critical scales at which it appears. 6We illustrate the approach on forest tree communities in Equatorial Guinea, where a phylogenetic clustering signal was probably due to phylogenetically conserved adaptations to the elevation gradient and was mostly contributed to by ancient clade subdivisions. 7The approach presented should find applications for comparing quantitatively phylogenetic patterns of different communities, of similar communities in different regions or continents, or of populations (within species) vs. communities (among species). [source] Host specificity and incidence of Trypanosoma in some African rainforest birds: a molecular approachMOLECULAR ECOLOGY, Issue 9 2001Ravinder N. M. Sehgal Abstract Studies of host,parasite interactions in birds have contributed greatly to our understanding of the evolution and ecology of disease. Here we employ molecular techniques to determine the incidence and study the host-specificity of parasitic trypanosomes in the African avifauna. We developed a polymerase chain reaction (PCR)-based diagnostic test that amplified the small subunit ribosomal RNA gene (SSU rRNA) of Trypanosoma from avian blood samples. This nested PCR assay complements and corroborates information obtained by the traditional method of blood smear analysis. The test was used to describe the incidence of trypanosomes in 479 host individuals representing 71 rainforest bird species from Cameroon, the Ivory Coast and Equatorial Guinea. Forty-two (59%) of these potential host species harboured trypanosomes and 189 individuals (35%) were infected. To examine host and geographical specificity, we examined the morphology and sequenced a portion of the SSU rRNA gene from representative trypanosomes drawn from different hosts and collecting locations. In traditional blood smear analyses we identified two trypanosome morphospecies, T. avium and T. everetti. Our molecular and morphological results were congruent in that these two morphospecies had highly divergent SSU rRNA sequences, but the molecular assay also identified cryptic variation in T. avium, in which we found seven closely allied haplotypes. The pattern of sequence diversity within T. avium provides evidence for widespread trypanosome mixing across avian host taxa and across geographical locations. For example, T. avium lineages with identical haplotypes infected birds from different families, whereas single host species were infected by T. avium lineages with different haplotypes. Furthermore, some conspecific hosts from geographically distant sampling locations were infected with the same trypanosome lineage, but other individuals from those locations harboured different trypanosome lineages. This apparent lack of host or geographical specificity may have important consequences for the evolutionary and ecological interactions between parasitic trypanosomes and their avian hosts. [source] Trapper profiles and strategies: insights into sustainability from hunter behaviourANIMAL CONSERVATION, Issue 6 2009N. F. Kümpel Abstract Hunters are the critical link between demand and supply of bushmeat. An understanding of the incentives that drive hunter behaviour might thus help to predict the impacts of hunting and inform management of bushmeat hunting systems. However, hunter behaviour has been generally under-represented in studies of exploitation, in particular trapper behaviour, despite the fact that trapping is the most common form of hunting in central Africa. We collected data on hunter profiles and measures of catch and effort over 15 months in the Monte Mitra area of continental Equatorial Guinea, through interviews, hunter follows and an offtake survey. Younger trappers, and those not born in the village, were found to expend the greatest trapping effort. Trappers operated under three distinct strategies, reflecting different levels of effort and impact: low-impact village trappers, medium-impact forest trappers and high-impact forest trappers. Among different measures of effort, time expended and distance travelled were found to be less important in predicting trapping success than the number of effective traps, a measure that incorporates trap age. Regular checking of traps was found to be important in reducing wastage and therefore increases trapping success. Trapping is currently the main hunting method in Monte Mitra, due to lower barriers to entry and higher profits compared with gun hunting, but increasing affordability and availability of guns and cartridges warns of a possible future switch to gun hunting in the area, which is likely to have adverse impacts on vulnerable species, particularly arboreal primates. An understanding of the influence of a hunter's profile on hunting effort and success enables a prediction of the impacts of socioeconomic changes on wildlife populations and management actions to improve hunting sustainability. [source] Linkages between household wealth, bushmeat and other animal protein consumption are not invariant: evidence from Rio Muni, Equatorial GuineaANIMAL CONSERVATION, Issue 6 2009J. E. Fa Abstract Bushmeat consumption is affected by household wealth. However, how household wealth impacts bushmeat eaten in different environmental and social settings (i.e. whether urban, rural, coastal or forest) is poorly understood. In this study, we sampled households in six contrasting localities in Rio Muni, Equatorial Guinea, in coastal (Bata, Cogo), central (Niefang, Evinayong) and eastern parts of the territory (Ebebiyin, Nsork). On average, 32.3 g of bushmeat per adult male equivalent per day were consumed, though this varied widely between sites and most households ate no bushmeat on the survey day. Fish was the most frequently recorded source of protein and in a coastal site, Cogo, significantly more fish was consumed than in the other localities. Overall, average protein consumption was correlated with household wealth, but the strength of this effect varied among sites. At the site where average wealth was highest (Bata, the most urban site), bushmeat was more expensive, and wealthier households ate more of it. Elsewhere bushmeat consumption was not associated with wealth, and the cost of bushmeat was a higher proportion of household wealth. In Bata, wealthier households reported consumption of more than one meat type (most frequently bushmeat and either domestic meat or fish), and diversity of dietary items also increased with wealth. In all sites, wealthier households ate less fish. We demonstrate distinct differences in relationships between urban versus rural areas, and between coastal versus inland sites. We therefore caution that general patterns of wealth,wild meat consumption must be evaluated taking account the circumstances of wild meat consumers. [source] | |||||||||||||