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Sample records for african geminivirus species

  1. Limitation in detecting African cassava mosaic geminivirus in the ...

    African Journals Online (AJOL)

    SERVER

    2007-10-18

    symptomatic (I) stems of the moderately-resistant ... 30001. Key words: African cassava mosaic geminivirus, infection status, cassava genotypes, detection limitations, .... soil maintained in an insect-proof greenhouse. There were ...

  2. Differential interaction between cassava mosaic geminiviruses and geminivirus satellites.

    Science.gov (United States)

    Patil, Basavaprabhu L; Fauquet, Claude M

    2010-07-01

    Geminiviruses are often associated with subviral agents called DNA satellites that require proteins encoded by the helper virus for their replication, movement and encapsidation. Hitherto, most of the single-stranded DNA satellites reported to be associated with members of the family Geminiviridae have been associated with monopartite begomoviruses. Cassava mosaic disease is known to be caused by viruses belonging to nine different begomovirus species in the African continent and the Indian subcontinent. In addition to these species, several strains have been recognized that exhibit contrasting phenotypes and infection dynamics. It is established that Sri Lankan cassava mosaic virus can trans-replicate betasatellites and can cross host barriers. To extend these studies further, we carried out an exhaustive investigation of the ability of geminiviruses, selected to represent all cassava-infecting geminivirus species, to trans-replicate betasatellites (DNA-beta) and to interact with alphasatellites (nanovirus-like components; previously called DNA-1). Each of the cassava-infecting geminiviruses showed a contrasting and differential interaction with the DNA satellites, not only in the capacity to interact with these molecules but also in the modulation of symptom phenotypes by the satellites. These observations could be extrapolated to field situations in order to hypothesize about the possibility of acquisition of such DNA satellites currently associated with other begomoviruses. These results call for more detailed analyses of these subviral components and an investigation of their possible interaction with the cassava mosaic disease complex.

  3. Geminivirus data warehouse: a database enriched with machine learning approaches.

    Science.gov (United States)

    Silva, Jose Cleydson F; Carvalho, Thales F M; Basso, Marcos F; Deguchi, Michihito; Pereira, Welison A; Sobrinho, Roberto R; Vidigal, Pedro M P; Brustolini, Otávio J B; Silva, Fabyano F; Dal-Bianco, Maximiller; Fontes, Renildes L F; Santos, Anésia A; Zerbini, Francisco Murilo; Cerqueira, Fabio R; Fontes, Elizabeth P B

    2017-05-05

    The Geminiviridae family encompasses a group of single-stranded DNA viruses with twinned and quasi-isometric virions, which infect a wide range of dicotyledonous and monocotyledonous plants and are responsible for significant economic losses worldwide. Geminiviruses are divided into nine genera, according to their insect vector, host range, genome organization, and phylogeny reconstruction. Using rolling-circle amplification approaches along with high-throughput sequencing technologies, thousands of full-length geminivirus and satellite genome sequences were amplified and have become available in public databases. As a consequence, many important challenges have emerged, namely, how to classify, store, and analyze massive datasets as well as how to extract information or new knowledge. Data mining approaches, mainly supported by machine learning (ML) techniques, are a natural means for high-throughput data analysis in the context of genomics, transcriptomics, proteomics, and metabolomics. Here, we describe the development of a data warehouse enriched with ML approaches, designated geminivirus.org. We implemented search modules, bioinformatics tools, and ML methods to retrieve high precision information, demarcate species, and create classifiers for genera and open reading frames (ORFs) of geminivirus genomes. The use of data mining techniques such as ETL (Extract, Transform, Load) to feed our database, as well as algorithms based on machine learning for knowledge extraction, allowed us to obtain a database with quality data and suitable tools for bioinformatics analysis. The Geminivirus Data Warehouse (geminivirus.org) offers a simple and user-friendly environment for information retrieval and knowledge discovery related to geminiviruses.

  4. Engineering Plants for Geminivirus Resistance with CRISPR/Cas9 System

    KAUST Repository

    Zaidi, Syed Shan-e-Ali

    2016-02-14

    The CRISPR/Cas9 system is an efficient genome-editing platform for diverse eukaryotic species, including plants. Recent work harnessed CRISPR/Cas9 technology to engineer resistance to geminiviruses. Here, we discuss opportunities, emerging developments, and potential pitfalls for using this technology to engineer resistance against single and multiple geminivirus infections in plants.

  5. Identification and characterisation of a highly divergent geminivirus: evolutionary and taxonomic implications.

    Science.gov (United States)

    Bernardo, Pauline; Golden, Michael; Akram, Mohammad; Naimuddin; Nadarajan, Nagaswamy; Fernandez, Emmanuel; Granier, Martine; Rebelo, Anthony G; Peterschmitt, Michel; Martin, Darren P; Roumagnac, Philippe

    2013-10-01

    During a large scale "non a priori" survey in 2010 of South African plant-infecting single stranded DNA viruses, a highly divergent geminivirus genome was isolated from a wild spurge, Euphorbia caput-medusae. In addition to being infectious in E. caput-medusae, the cloned viral genome was also infectious in tomato and Nicotiana benthamiana. The virus, named Euphorbia caput-medusae latent virus (EcmLV) due to the absence of infection symptoms displayed by its natural host, caused severe symptoms in both tomato and N. benthamiana. The genome organisation of EcmLV is unique amongst geminiviruses and it likely expresses at least two proteins without any detectable homologues within public sequence databases. Although clearly a geminivirus, EcmLV is so divergent that we propose its placement within a new genus that we have tentatively named Capulavirus. Using a set of highly divergent geminiviruses genomes, it is apparent that recombination has likely been a primary process in the genus-level diversification of geminiviruses. It is also demonstrated how this insight, taken together with phylogenetic analyses of predicted coat protein and replication associated protein (Rep) amino acid sequences indicate that the most recent common ancestor of the geminiviruses was likely a dicot-infecting virus that, like modern day mastreviruses and becurtoviruses, expressed its Rep from a spliced complementary strand transcript. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Evolution of geminiviruses and their satellites.

    Science.gov (United States)

    Nawaz-ul-Rehman, Muhammad Shah; Fauquet, Claude M

    2009-06-18

    Geminiviruses and their satellites have circular single stranded DNA genomes, infecting many crops and weeds across the globe. To successfully invade new hosts, break host resistance, move virus particles within and between plants, geminiviruses and their satellites have evolved a coordinated network of protein interactions, showing a possible evolutionary path. Humans have played an important role in the last century to promote the emergence of many geminivirus diseases, thereby impacting their evolution. The greatest molecular diversity of geminiviruses and their satellites resides in Southeast Asia revealing a possible center of origin. This minireview leads us to a possible general grand scheme of their evolution.

  7. Echinococcus species in African wildlife.

    Science.gov (United States)

    Hüttner, M; Romig, T

    2009-09-01

    Cystic echinococcosis, caused by different species of the Echinococcus granulosus complex, is an important zoonotic disease with a particular impact on pastoralist societies. In addition to the widespread taxa with synanthropic transmission, a number of Echinococcus species were described from African wild carnivores early in the 20th century. For lack of study material, most of these were later tentatively synonymized with E. granulosus. Early infection experiments with wildlife isolates gave ambiguous results due to the use of unspecified parasite material, and only recently molecular methods provided the opportunity to shed light on the confusing scenery e.g. by characterizing E. felidis from the African lion. Here we will summarize the convoluted history of Echinococcus research in sub-Saharan Africa and highlight the necessity of molecular surveys to establish the life cycles and estimate the zoonotic potential of these parasites.

  8. Characterization of tobacco geminiviruses in the Old and New World.

    Science.gov (United States)

    Paximadis, M; Idris, A M; Torres-Jerez, I; Villarreal, A; Rey, M E; Brown, J K

    1999-01-01

    Biological differences and molecular variability between six phenotypically distinct tobacco-infecting geminivirus isolates from southern Africa (Zimbabwe) and Mexico were investigated. Host range studies conducted with tobacco virus isolates ZIM H from Zimbabwe and MEX 15 and MEX 32 from Mexico indicated all had narrow host ranges restricted to the Solanaceae. Alignment of coat protein gene (CP) and common region (CR) sequences obtained by PCR, and phylogenetic analysis of the CP sequences indicated Zimbabwean isolates were distantly related to those from Mexico and that geographically proximal isolates shared their closest affinities with Old and New World geminiviruses, respectively. Zimbabwean isolates formed a distinct cluster of closely related variants (> 98% sequence identity) of the same species, while MEX 15 segregated independently from MEX 32, the former constituting a distinct species among New World geminiviruses, and the latter being a variant, Texas pepper virus-Chiapas isolate (TPV-CPS) with 95% sequence identity to TPV-TAM. Results collectively indicated a geographic basis for phylogenetic relationships rather than a specific affiliation with tobacco as a natural host. MEX 15 is provisionally described as a new begomovirus, tobacco apical stunt virus, TbASV, whose closest CP relative is cabbage leaf curl virus, and ZIM isolates are provisionally designated as tobacco leaf curl virus, TbLCV-ZIM, a new Eastern Hemisphere begomovirus, which has as its closest relative, chayote mosaic virus from Nigeria.

  9. East African cassava mosaic Zanzibar virus - a recombinant begomovirus species with a mild phenotype.

    Science.gov (United States)

    Maruthi, M N; Seal, S; Colvin, J; Briddon, R W; Bull, S E

    2004-12-01

    Cassava plants exhibiting mild symptoms of cassava mosaic disease (CMD) were collected from Unguja island, Zanzibar. Cuttings grown from these plants in the glasshouse produced similar symptoms, which were milder than those caused by other known cassava mosaic geminiviruses (CMGs). The whitefly vector, Bemisia tabaci (Gennadius), transmitted the putative virus to 27.7% (n = 18) of target plants. Total DNA extracted from diseased leaves did not yield diagnostic PCR-bands using virus-specific primers to known CMGs. Degenerate primers, however, produced a diagnostic band indicating the presence of a begomovirus. Full-length DNA-A (2785 nucleotides) and DNA-B (2763 nucleotides) components were subsequently PCR-amplified, cloned and sequenced. Phylogenetic analyses of DNA-A and -B sequences showed that they were most similar to strains of East African cassava mosaic virus from Tanzania and Uganda at 83% and 86% nucleotide identities, respectively. The number and arrangement of open reading frames were similar to those of bipartite begomoviruses from the Old World. DNA-A was predicted to have recombined in the intergenic region (IR), AC1 and AC4 genes, and DNA-B in the IR. A maximum nucleotide identity of 83% in the DNA-A component with other sequenced begomoviruses, together with different biological properties allows this virus to be recognised as belonging to a new species named East African cassava mosaic Zanzibar virus (EACMZV).

  10. Analogies between geminivirus and oncovirus: Cell cycle regulation ...

    African Journals Online (AJOL)

    Geminiviruses are a large family of plant viruses whose genome is composed of one or two circular and single strand of DNA. They replicate in the cell nucleus being Rep protein, the only viral protein necessary for their replication process. Geminiviruses as same as animal DNA oncoviruses, like SV40, adenovirus and ...

  11. Geminiviruses: a tale of a plasmid becoming a virus

    Directory of Open Access Journals (Sweden)

    Krupovic Mart

    2009-05-01

    Full Text Available Abstract Background Geminiviruses (family Geminiviridae are small single-stranded (ss DNA viruses infecting plants. Their virion morphology is unique in the known viral world – two incomplete T = 1 icosahedra are joined together to form twinned particles. Geminiviruses utilize a rolling-circle mode to replicate their genomes. A limited sequence similarity between the three conserved motifs of the rolling-circle replication initiation proteins (RCR Reps of geminiviruses and plasmids of Gram-positive bacteria allowed Koonin and Ilyina to propose that geminiviruses descend from bacterial replicons. Results Phylogenetic and clustering analyses of various RCR Reps suggest that Rep proteins of geminiviruses share a most recent common ancestor with Reps encoded on plasmids of phytoplasmas, parasitic wall-less bacteria replicating both in plant and insect cells and therefore occupying a common ecological niche with geminiviruses. Capsid protein of Satellite tobacco necrosis virus was found to be the best template for homology-based structural modeling of the geminiviral capsid protein. Good stereochemical quality of the generated models indicates that the geminiviral capsid protein shares the same structural fold, the viral jelly-roll, with the vast majority of icosahedral plant-infecting ssRNA viruses. Conclusion We propose a plasmid-to-virus transition scenario, where a phytoplasmal plasmid acquired a capsid-coding gene from a plant RNA virus to give rise to the ancestor of geminiviruses.

  12. Statistical Analysis on Detecting Recombination Sites in DNA-β Satellites Associated with Old World Geminiviruses

    Science.gov (United States)

    Xu, Kai; Yoshida, Ruriko

    2010-01-01

    Although exchange of genetic information by recombination plays an important role in the evolution of viruses, it is not clear how it generates diversity. Understanding recombination events helps with the study of the evolution of new virus strains or new viruses. Geminiviruses are plant viruses which have ambisense single-stranded circular DNA genomes and are one of the most economically important plant viruses in agricultural production. Small circular single-stranded DNA satellites, termed DNA-β, have recently been found to be associated with some geminivirus infections. In this paper we analyze several DNA-β sequences of geminiviruses for recombination events using phylogenetic and statistical analysis and we find that one strain from ToLCMaB has a recombination pattern and is a recombinant molecule between two strains from two species, PaLCuB-[IN:Chi:05] (major parent) and ToLCB-[IN:CP:04] (minor parent). We propose that this recombination event contributed to the evolution of the strain of ToLCMaB in South India. The Hidden Markov Chain (HMM) method developed by Webb et al. (2009) estimating phylogenetic tree through out the whole alignment provide us a recombination history of these DNA-β strains. It is the first time that this statistic method has been used on DNA-β recombination study and give a clear recombination history of DNA-β recombination. PMID:21423447

  13. Alfalfa Leaf Curl Virus: an Aphid-Transmitted Geminivirus.

    Science.gov (United States)

    Roumagnac, Philippe; Granier, Martine; Bernardo, Pauline; Deshoux, Maëlle; Ferdinand, Romain; Galzi, Serge; Fernandez, Emmanuel; Julian, Charlotte; Abt, Isabelle; Filloux, Denis; Mesléard, François; Varsani, Arvind; Blanc, Stéphane; Martin, Darren P; Peterschmitt, Michel

    2015-09-01

    The family Geminiviridae comprises seven genera differentiated by genome organization, sequence similarity, and insect vector. Capulavirus, an eighth genus, has been proposed to accommodate two newly discovered highly divergent geminiviruses that presently have no known vector. Alfalfa leaf curl virus, identified here as a third capulavirus, is shown to be transmitted by Aphis craccivora. This is the first report of an aphid-transmitted geminivirus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Notes on the cytogenetics of some South African Xiphinema species ...

    African Journals Online (AJOL)

    The cytogenetics of several South African species of Xiphinemawere studied and compared with the existing data for this genus from Europe. The process of oogenesis appears to be very similar in all species studied, with little interspecific and intraspecific differences. The ovaries of the South African specimens are larger, ...

  15. Notes on the cytogenetics of some South African Xiphinema species ...

    African Journals Online (AJOL)

    1988-03-31

    Mar 31, 1988 ... The cytogenetics of several South African species of Xiphinema were studied and compared with the existing data for this genus from Europe. The process of oogenesis appears to be very similar in all species studied, with little interspecific and intraspecific differences. The ovaries of the South African ...

  16. Reproductive characterization of three species of Giant African land ...

    African Journals Online (AJOL)

    Administrator

    2011-09-05

    Sep 5, 2011 ... species of Giant African land snails (GALs) namely, Achatina fulica, Archachatina marginata and. Achatina ... Key words: Land snails, courtship, copulatory duration, tentacular contact, monocultures. INTRODUCTION ..... male parental care: premating isolation and chromosome variation. Marine Biol.

  17. Seaweed species diversity in South Africa | Bolton | African Journal ...

    African Journals Online (AJOL)

    A dataset is presented on the diversity of South African seaweed species and their distribution in contiguous 50-km coastal sections, to demonstrate current knowledge of the flora in various coastal regions. The coastline has a rich flora, consisting of some 800 species. The South Coast has the highest species diversity ...

  18. Geminivirus-Mediated Genome Editing in Potato (Solanum tuberosum L.) Using Sequence-Specific Nucleases.

    Science.gov (United States)

    Butler, Nathaniel M; Baltes, Nicholas J; Voytas, Daniel F; Douches, David S

    2016-01-01

    Genome editing using sequence-specific nucleases (SSNs) is rapidly being developed for genetic engineering in crop species. The utilization of zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and clustered regularly interspaced short palindromic repeats/CRISPR-associated systems (CRISPR/Cas) for inducing double-strand breaks facilitates targeting of virtually any sequence for modification. Targeted mutagenesis via non-homologous end-joining (NHEJ) has been demonstrated extensively as being the preferred DNA repair pathway in plants. However, gene targeting via homologous recombination (HR) remains more elusive but could be a powerful tool for directed DNA repair. To overcome barriers associated with gene targeting, a geminivirus replicon (GVR) was used to deliver SSNs targeting the potato ACETOLACTATE SYNTHASE1 (ALS1) gene and repair templates designed to incorporate herbicide-inhibiting point mutations within the ALS1 locus. Transformed events modified with GVRs held point mutations that were capable of supporting a reduced herbicide susceptibility phenotype, while events transformed with conventional T-DNAs held no detectable mutations and were similar to wild-type. Regeneration of transformed events improved detection of point mutations that supported a stronger reduced herbicide susceptibility phenotype. These results demonstrate the use of geminiviruses for delivering genome editing reagents in plant species, and a novel approach to gene targeting in a vegetatively propagated species.

  19. Geminivirus-mediated genome editing in potato (Solanum tuberosum L. using sequence-specific nucleases

    Directory of Open Access Journals (Sweden)

    Nathaniel M Butler

    2016-07-01

    Full Text Available Genome editing using sequence-specific nucleases (SSNs is rapidly being developed for genetic engineering in crop species. The utilization of zinc finger nucleases (ZFNs, transcription activator-like effector nucleases (TALENs and CRISPR/Cas (clustered regularly interspaced short palindromic repeats (CRISPR/CRISPR-associated systems (Cas for inducing double-strand breaks facilitates targeting of virtually any sequence for modification. Targeted mutagenesis via nonhomologous end-joining has been demonstrated extensively as being the preferred DNA repair pathway in plants. However, gene targeting via homologous recombination remains more elusive but could be a powerful tool for directed DNA repair. To overcome barriers associated with gene targeting, a geminivirus replicon (GVR was used to deliver SSNs targeting the potato ACETOLACTATE SYNTHASE1 (ALS1 gene and repair templates designed to incorporate herbicide-inhibiting point mutations within the ALS1 locus. Transformed events modified with GVRs held both point mutations that were capable of supporting a reduced herbicide susceptibility phenotype, while events transformed with conventional T-DNAs held no detectable mutations and were similar to wild-type. Regeneration of transformed events improved detection of point mutations that supported a stronger reduced herbicide susceptibility phenotype. These results demonstrate the use of geminiviruses for delivering genome editing reagents in plant species, and an approach to gene targeting in a vegetatively propagated species.

  20. Salinity ranges of some southern African fish species occurring in ...

    African Journals Online (AJOL)

    The recorded salinity ranges of 96 fish species occurring in southern African estuaries are documented. Factors influen- cing the tolerance of fishes to low and high salinity regimes are discussed, with most species tolerant of low rather than high salinity conditions. This is important since most systems are subject to periodic ...

  1. The status of some southern African nominal species of Cucumaria ...

    African Journals Online (AJOL)

    1986-05-19

    May 19, 1986 ... African species is given, their synonymy detailed, additional notes provided, and the geographic distributions mapped. Although P. sykion and P. ... and the zoogeographic distribution, ecology and relationships of the species ..... Stone canal and polian vesicle single; each retractor muscle composed of 4-7 ...

  2. Echolocation caBs of twenty southern African bat species

    African Journals Online (AJOL)

    all species, and added that intensity and harmonic information. (not available through ANABAT recordings) would have proved useful for identification. The aim of this study is to present new echolocation data for. 20 southern African species using a time-expansion Petters- son D980 bat detector, particularly with the view to ...

  3. Sinaloa Tomato Leaf Curl Geminivirus: Biological and Molecular Evidence for a New Subgroup III Virus.

    Science.gov (United States)

    Idris, A M; Brown, J K

    1998-07-01

    ABSTRACT The biological and molecular properties of Sinaloa tomato leaf curl virus (STLCV) were investigated in line with the hypothesis that STLCV is a previously uncharacterized, whitefly-transmitted geminivirus from North America. STLCV causes yellow leaf curl symptoms in tomato and yellow-green foliar mottle in pepper. Five species belonging to two plant families were STLCV experimental hosts. STLCV had a persistent relationship with its whitefly vector, Bemisia tabaci. Polymerase chain reaction fragments of STLCV common region (CR) sequences of the A or B genomic components and the viral coat protein gene (AV1) were molecularly cloned and sequenced. The STLCV A- and B-component CR sequences (174 nucleotides each) shared 97.9% identity and contained identical cis elements putatively involved in transcriptional regulation and an origin of replication (the AC cleavage site within the loop of the hairpin structure and two direct repeat sequences thought to constitute the Rep binding motif), which collectively are diagnostic for subgroup III geminiviruses. The STLCV CR sequence shared 23.1 to 77.6% identity with CR sequences of representative geminiviridae, indicating the STLCV CR sequence is unique. Molecular phylogenetic analysis of CR or AV1 sequences of STLCV and the respective sequences of 31 familial members supported the placement of STLCV as a unique bipartite, subgroup III virus most closely related to other viruses from the Western Hemisphere. STLCV is provisionally described as a new species within the genus Begomovirus, family Geminiviridae.

  4. Unraveling the medicinal potential of South African Aloe species.

    Science.gov (United States)

    Amoo, Stephen O; Aremu, Adeyemi O; Van Staden, Johannes

    2014-04-11

    Aloe species (family: Xanthorrhoeaceae) are widely used in ethnomedicine for treating various ailments. Approximately 125 Aloe taxa are documented as indigenous to South Africa. This review was aimed at critically evaluating the available data on the ethnomedicinal uses, pharmacological activities, safety and conservation status of the documented South African Aloe species. A detailed search using major electronic search engines (such as Google Scholar, Scopus and Scirus) and ethnobotanical literature was undertaken. Search terms used included 'medicinal properties of Aloe species', 'biological activity of South African Aloe species' and 'safety and toxicological evaluation of aloes'. Although Aloe species are widely used as laxatives and for treating wound and skin-related ailments, only about 20% of South African Aloe species have been clearly documented for their medicinal uses. The pharmacological potential including the antimicrobial, antiinflammatory, antiplasmodial and anthelmintic activities of some of the species has been established, providing a rationale for their use in traditional medicine. Successful micropropagation protocols have been developed as a conservation strategy, but only for a few species. The highlighted medicinal activities of some Aloe species indicate their therapeutic potential. Nonetheless, further research especially on the understudied species is required to properly document their ethnomedicinal uses and fully explore their pharmacological value. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. A Revision of the African Species of Epilobium

    Directory of Open Access Journals (Sweden)

    Peter H Raven

    1967-11-01

    Full Text Available There are in Africa 10 native species of Epilobium, one of Circaea, and between 8 and 12 of Ludwigia (including  Jussiaea, depending upon how many species are considered native. These three genera include all native African species of Onagraceae. Four sections of Ludwigia, cornprising a total of five species, and one fairly distinctive group of Epilobium are the most characteristic African groups. Despite the fact that H. Perrier de la Bathie (in Humb., FI. Madagasc., Oenotheracs : 1-26, 1950 considered all three of the species of Epilobium that he recognized and four of the 11 species of Ludwigia (including  Jussiaea to be endemic to Madagascar, there are in my opinion no Mascarene endemics in the family Onagraceae and nothing to suggest any great antiquity for the family on that island. This observation agrees with the general pattern for the family in Africa in suggesting that plants of this family are relatively recent arrivals on that continent. Indeed this generality could be extended to apply to the Old World as a whole, where there is no endemic genus of the family (as opposed to 16 endemic genera and 2 endemic tribes—Lopezieae and Onagreae—in the New World, principally in Mexico and the western United States and relatively few endemic sections or subgenera. The ten African species and one subspecies of  Epilobium recognized are described, and a key provided.

  6. Reproductive characterization of three species of Giant African land ...

    African Journals Online (AJOL)

    Duration of reproductive activities (courtship latency, courtship and mating) were studied in three (3) species of Giant African land snails (GALs) namely, Achatina fulica, Archachatina marginata and Achatina achatina using mature snails gathered from rural Nigeria. The snails were housed singly for 90 days to acclimatize; ...

  7. Three species of piscine parasitic copepods from southern African ...

    African Journals Online (AJOL)

    Three species of piscine parasitic copepods previously undescribed from southern African coastal waters were studied. Although sampling data are incomplete, Lepeopthirius nordmanni(Edwards, 1840) taken from Thunnus and Mola spp., Euryphorus brachypterus (Gerstaecker, 1853) from unknown host and locality and ...

  8. Three species of piscine parasitic copepods from southern African ...

    African Journals Online (AJOL)

    1992-09-04

    Sep 4, 1992 ... Three species of piscine parasitic copepods previously undescribed from southern African coastal waters were studied. Although sampling data are incomplete, Lep90pthirius nordmanni (Edwards, 1840) taken from. Thu'!nus an~ Mo~a spp., Euryphorus brachypterus (Gerstaecker, 1853) from unknown host ...

  9. Two new African species of Salacia (Salacioideae, Celastraceae)

    NARCIS (Netherlands)

    Gosline, G.; Cheek, M.

    2014-01-01

    Two new African species of Salacia (Salacioideae, Celastraceae) are described. Salacia arenicola is a scandent shrub endemic to a restricted white sand habitat in coastal Republic of Congo. It is assessed as IUCN 2012 category Vulnerable (VU). Salacia nigra is an erect shrub or small tree with dark

  10. African ancestry of New World, Bemisia tabaci-whitefly species.

    Science.gov (United States)

    Mugerwa, Habibu; Seal, Susan; Wang, Hua-Ling; Patel, Mitulkumar V; Kabaalu, Richard; Omongo, Christopher A; Alicai, Titus; Tairo, Fred; Ndunguru, Joseph; Sseruwagi, Peter; Colvin, John

    2018-02-09

    Bemisia tabaci whitefly species are some of the world's most devastating agricultural pests and plant-virus disease vectors. Elucidation of the phylogenetic relationships in the group is the basis for understanding their evolution, biogeography, gene-functions and development of novel control technologies. We report here the discovery of five new Sub-Saharan Africa (SSA) B. tabaci putative species, using the partial mitochondrial cytochrome oxidase 1 gene: SSA9, SSA10, SSA11, SSA12 and SSA13. Two of them, SSA10 and SSA11 clustered with the New World species and shared 84.8‒86.5% sequence identities. SSA10 and SSA11 provide new evidence for a close evolutionary link between the Old and New World species. Re-analysis of the evolutionary history of B. tabaci species group indicates that the new African species (SSA10 and SSA11) diverged from the New World clade c. 25 million years ago. The new putative species enable us to: (i) re-evaluate current models of B. tabaci evolution, (ii) recognise increased diversity within this cryptic species group and (iii) re-estimate divergence dates in evolutionary time.

  11. Studies in the southern African species of Justicia and Siphonoglossa (Acanthaceae: palynology

    Directory of Open Access Journals (Sweden)

    K. L. Immelman

    1989-12-01

    Full Text Available The gross morphology of the pollen of all southern African species and subspecies of Justicia and  Siphonoglossa was investigated, as well as that of eight tropical African species of  Justicia. The following pollen types were found in the southern African species of Justicia:  two- or three-colporate, each with the margocolpus either entire or broken up into areolae, and two-porate areolate pollen. One tropical African species had the colpus very short, and in another tropical African species it was replaced by an extra row of areolae. All  Siphonoglossa species had two-colporate pollen with areolae and long colpi. The southern African species of Justicia could be separated from  Siphonoglossa on pollen characters, and some sections of Justicia could also be distinguished on the same basis.

  12. Increased pathogenicity in a pseudorecombinant bipartite geminivirus correlates with intermolecular recombination.

    OpenAIRE

    Hou, Y M; Gilbertson, R L

    1996-01-01

    Most whitefly-transmitted geminiviruses possess bipartite DNA genomes, and this feature may facilitate viral evolution through pseudorecombination and/or recombination. To test this hypothesis, the DNA-A and DNA-B components of the geminiviruses bean dwarf mosaic virus (BDMV) and tomato mottle virus (ToMoV) were exchanged, and the resultant pseudorecombinants were serially passaged through plants. Both pseudorecombinants were infectious in Nicotiana benthamiana but induced attenuated symptoms...

  13. CRISPR/Cas9-Mediated Immunity to Geminiviruses: Differential Interference and Evasion

    KAUST Repository

    Ali, Zahir

    2016-05-26

    The CRISPR/Cas9 system has recently been used to confer molecular immunity against several eukaryotic viruses, including plant DNA geminiviruses. Here, we provide a detailed analysis of the efficiencies of targeting different coding and non-coding sequences in the genomes of multiple geminiviruses. Moreover, we analyze the ability of geminiviruses to evade the CRISPR/Cas9 machinery. Our results demonstrate that the CRISPR/Cas9 machinery can efficiently target coding and non-coding sequences and interfere with various geminiviruses. Furthermore, targeting the coding sequences of different geminiviruses resulted in the generation of viral variants capable of replication and systemic movement. By contrast, targeting the noncoding intergenic region sequences of geminiviruses resulted in interference, but with inefficient recovery of mutated viral variants, which thus limited the generation of variants capable of replication and movement. Taken together, our results indicate that targeting noncoding, intergenic sequences provides viral interference activity and significantly limits the generation of viral variants capable of replication and systemic infection, which is essential for developing durable resistance strategies for long-term virus control.

  14. Lanai: A small, fast growing tomato variety is an excellent model system for studying geminiviruses.

    Science.gov (United States)

    Rajabu, C A; Kennedy, G G; Ndunguru, J; Ateka, E M; Tairo, F; Hanley-Bowdoin, L; Ascencio-Ibáñez, J T

    2018-03-09

    Geminiviruses are devastating single-stranded DNA viruses that infect a wide variety of crops in tropical and subtropical areas of the world. Tomato, which is a host for more than 100 geminiviruses, is one of the most affected crops. Developing plant models to study geminivirus-host interaction is important for the design of virus management strategies. In this study, "Florida Lanai" tomato was broadly characterized using three begomoviruses (Tomato yellow leaf curl virus, TYLCV; Tomato mottle virus, ToMoV; Tomato golden mosaic virus, TGMV) and a curtovirus (Beet curly top virus, BCTV). Infection rates of 100% were achieved by agroinoculation of TYLCV, ToMoV or BCTV. Mechanical inoculation of ToMoV or TGMV using a microsprayer as well as whitefly transmission of TYLCV or ToMoV also resulted in 100% infection frequencies. Symptoms appeared as early as four days post inoculation when agroinoculation or bombardment was used. Symptoms were distinct for each virus and a range of features, including plant height, flower number, fruit number, fruit weight and ploidy, was characterized. Due to its small size, rapid growth, ease of characterization and maintenance, and distinct responses to different geminiviruses, "Florida Lanai" is an excellent choice for comparing geminivirus infection in a common host. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  15. gb4gv: a genome browser for geminivirus

    Directory of Open Access Journals (Sweden)

    Eric S. Ho

    2017-04-01

    Full Text Available Background Geminiviruses (family Geminiviridae are prevalent plant viruses that imperil agriculture globally, causing serious damage to the livelihood of farmers, particularly in developing countries. The virus evolves rapidly, attributing to its single-stranded genome propensity, resulting in worldwide circulation of diverse and viable genomes. Genomics is a prominent approach taken by researchers in elucidating the infectious mechanism of the virus. Currently, the NCBI Viral Genome website is a popular repository of viral genomes that conveniently provides researchers a centralized data source of genomic information. However, unlike the genome of living organisms, viral genomes most often maintain peculiar characteristics that fit into no single genome architecture. By imposing a unified annotation scheme on the myriad of viral genomes may downplay their hallmark features. For example, the viron of begomoviruses prevailing in America encapsulates two similar-sized circular DNA components and both are required for systemic infection of plants. However, the bipartite components are kept separately in NCBI as individual genomes with no explicit association in linking them. Thus, our goal is to build a comprehensive Geminivirus genomics database, namely gb4gv, that not only preserves genomic characteristics of the virus, but also supplements biologically relevant annotations that help to interrogate this virus, for example, the targeted host, putative iterons, siRNA targets, etc. Methods We have employed manual and automatic methods to curate 508 genomes from four major genera of Geminiviridae, and 161 associated satellites obtained from NCBI RefSeq and PubMed databases. Results These data are available for free access without registration from our website. Besides genomic content, our website provides visualization capability inherited from UCSC Genome Browser. Discussion With the genomic information readily accessible, we hope that our database

  16. African hornbills: keystone species threatened by habitat loss ...

    African Journals Online (AJOL)

    However, there is evidence for serious declines of African forest hornbills due to habitat loss and fragmentation, and to unsustainable exploitation for bushmeat. In addition, this paper documents a previously unreported international trade involving importation of African hornbills and their parts into the United States.

  17. Somatic homologous recombination in plants is promoted by a geminivirus in a tissue-selective manner.

    Science.gov (United States)

    Richter, K S; Kleinow, T; Jeske, H

    2014-03-01

    Four transgenic Arabidopsis thaliana lines carrying different reporter gene constructs based on split glucuronidase genes were used to monitor the frequency of somatic homologous recombination after geminivirus infections. Euphorbia mosaic virus and Cleome leaf crumple virus were chosen as examples, because they induce only mild symptoms and are expected to induce less general stress responses than other geminiviruses. After comparing the different plant lines and viruses as well as optimizing the infection procedure, Euphorbia mosaic virus enhanced recombination rates significantly in the transgenic reporter line 1445. The effect was tissue-specific in cells of the leaf veins as expected for this phloem-limited virus. The advantage for geminiviruses to activate a general recombination pathway is discussed with reference to an increased fitness by generating virus recombinants which have been observed frequently as an epidemiologic driving force. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. African Crop Science Journal - Vol 2, No 4 (1994)

    African Journals Online (AJOL)

    The effects of cropping systems on cassava whiteflies in Colombia: implications for control of African cassava mosaic virus disease · EMAIL FREE FULL TEXT EMAIL ... Bemisia tabaci: the whitefly vector of cassava mosaic geminiviruses in Africa: an ecological perspective · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  19. Seaweed species diversity in South Africa | Bolton | African Journal ...

    African Journals Online (AJOL)

    African Journal of Marine Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 24 (2002) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  20. Polyandry and polygyny in an African rodent pest species, Mastomys natalensis

    DEFF Research Database (Denmark)

    Kennis, Jan; Sluydts, Vincent; Leirs, Herwig

    2008-01-01

    Males and females use different mating strategies and seldom have these strategies been studied on the field for cryptic rodent species. We studied the breeding strategies of both males and females of the sub-Sahara African rodent pest species, Mastomys natalensis, in the field using capture...... as a pest management technique due to the promiscuous mating and high frequency of sexual contacts....

  1. Polyandry and polygyny in an African rodent pest species, Mastomys natalensis

    NARCIS (Netherlands)

    Kennis, J.; Sluydts, V.; Leirs, H.; Hooft, van W.F.

    2008-01-01

    Males and females use different mating strategies and seldom have these strategies been studied on the field for cryptic rodent species. We studied the breeding strategies of both males and females of the sub-Sahara African rodent pest species, Mastomys natalensis, in the field using capture removal

  2. A novel cloning strategy for isolating, genotyping and phenotyping genetic variants of geminiviruses

    Directory of Open Access Journals (Sweden)

    Granier Martine

    2008-10-01

    Full Text Available Abstract Background Viruses of the genus Begomovirus (Geminiviridae are emerging economically important plant viruses with a circular, single-stranded DNA genome. Previous studies have shown that geminiviruses and RNA viruses exhibit similar mutation frequencies, although geminiviruses are replicated by host DNA polymerases and RNA viruses by their own virus-encoded error-prone RNA-dependent RNA-polymerase. However, the phenotypic effects of naturally occurring mutations have never been extensively investigated in geminiviruses, particularly because, to be infectious, cloned viral genomes usually require sub-cloning as complete or partial tandem repeats into a binary vector from Agrobacterium tumefaciens. Results Using Tomato yellow leaf curl virus (TYLCV, we show here that infectivity can be obtained when only a 41-nucleotide region containing a highly conserved stem-loop is repeated. A binary vector containing this 41-nt region and a unique restriction site was created, allowing direct cloning of infectious monomeric viral genomes provided that they harbour the same restriction site at the corresponding nucleotide position. This experimental system, which can be transferable to other geminiviruses, was validated by analysis of the phenotypic effect of mutations appearing in TYLCV genomes in a single tomato host plant originally inoculated with a unique viral sequence. Fourteen full-length infectious genomes extracted from this plant were directly cloned and sequenced. The mutation frequency was 1.38 × 10-4 mutation per nucleotide sequenced, similar to that found previously for another begomovirus by sequencing PCR-amplified partial sequences. Interestingly, even in this minimal pool of analysed genomes, mutants with altered properties were readily identified, one of them being fitter and reducing plant biomass more drastically than the parental clone. Conclusion The cloning strategy presented here is useful for any extensive phenotyping of

  3. An analysis of the African Acacia species: their distribution, possible origins and relationships

    Directory of Open Access Journals (Sweden)

    J. H. Ross

    1981-11-01

    Full Text Available The three subgenera recognized within the genus Acacia are outlined and the global distribution of each is indicated. The differences between the subgenera and the degree of relationship and levels of specialization are discussed briefly. It is suggested that the ancestral members of the genus were climbers or lianes. Past geological events considered likely to have influenced the distribution of the  Acacia species in Africa are outlined. The number of  species recorded from each African country is tabulated and the distribution and concentration of species within the genus Acacia as a whole and within each subgenus in Africa are illustrated. The highest concentrations of species within each subgenus occur in tropical east and south-east Africa. The distribution o f species within some o f the individual African countries and possible affinities are discussed and attention is drawn to the main centres of endemism. The distribution of the African species is correlated with the major phytogeographical regions recognized on the continent. The relationships between the African and the American, Madagascan, Indian and Australian  Acacia species are discussed briefly.

  4. A new species of Charinus (Amblypygi: Charinidae) from Ghana, with notes on West African whip spiders

    OpenAIRE

    Harms,Danilo

    2018-01-01

    The fauna of whip spiders (Amblypygi) in Western Africa is poorly known but probably diverse. Here, I describe the new species Charinus kakum sp. n. based on female morphology, and accompanied by DNA sequence data. The species is small and differs from other African species of Charinus in the low number of pseudosegments on leg IV, female genital features, spination patterns of the pedipalp, and small body size. It was collected from wet tropical rainforest in Kakum National Park, Ghana and i...

  5. Identity and distribution of southern African sciaenid fish species of ...

    African Journals Online (AJOL)

    Two Umbrina species, U. canariensis Valenciennes 1843 and U. robinsoni Gilchrist and Thompson 1908, are recognised from southern Africa. The latter species was hitherto believed to be a synonym of Umbrina ronchus Valenciennes 1843 (type locality Canary Islands). U. canariensis is distributed along the South Africa ...

  6. (OLIGOCHAETA) FROM SOUTH AFRICAN RIVERS Two species of ...

    African Journals Online (AJOL)

    dominantly terrestrial and contain species of relatively large body-size. Available collections .... fully withstanding invasion of non-indigenous species and modification by human activities of the composition of ..... of a "penis" which in Michaelsen's illustration has the appearance of the everted bursa seen in one specimen of ...

  7. Antibacterial activity of the five South African Erythroxylaceae species

    African Journals Online (AJOL)

    Administrator

    2011-09-21

    Sep 21, 2011 ... species (Bredenkamp, 2000), which occur in the Northern. Province, Mpumalanga, KwaZulu-Natal and the Eastern. Cape (Table 1). The best known species in this family is. Erythroxylum coca Lam. of which the leaves are traditionally chewed in the Andes region to relieve hunger and fatigue. It is also used ...

  8. The bioeconomics of controlling an African rodent pest species

    DEFF Research Database (Denmark)

    Skonhoft, Anders; Leirs, Herwig; Andreassen, Harry P

    2006-01-01

    The paper treats the economy of controlling an African pest rodent, the multimammate rat, causing major damage in maize production. An ecological population model is presented and used as a basis for the economic analyses carried out at the village level using data from Tanzania. This model...... incorporates both density-dependent and density-independent (stochastic) factors. Rodents are controlled by applying poison, and the costs are made up of the cost of poison plus the damage to maize production. We analyse how the present-value costs of maize production are affected by various rodent control...... strategies, by varying the duration and timing of rodenticide application. Our numerical results suggest that it is economically beneficial to control the rodent population. In general, the most cost-effective duration of controlling the rodent population is 3-4 months every year, and especially at the end...

  9. Heat stable peroxidases from Vigna species (V) | Mbassi | African ...

    African Journals Online (AJOL)

    Shoots of three landraces of a Vigna species from two climatic areas of Cameroon were evaluated for their content of heat-resistant peroxidases. The peroxidase activity in the three landraces was detected with a greater catalytic efficiency for oxidation of O-dianisidine relative to ABTS (2, 2'-azino-bis-(3- ...

  10. Salinity ranges of some southern African fish species occurring in ...

    African Journals Online (AJOL)

    Factors influencing the tolerance of fishes to low and high salinity regimes are discussed, with most species tolerant of low rather than high salinity conditions. This is important since most systems are subject to periodic freshwater flooding, especially during summer. The penetration of freshwater teleosts and elasmobranchs ...

  11. Occurrence of Klebsiella Species in Cultured African Catfish in Oyo ...

    African Journals Online (AJOL)

    Klebsiella species in the family of enterobacteriacea causes urinary tract infections, pneumonia, septicemias and soft tissue infections in human. ... The results show that all the 66 isolates were gram-negative, did not haemolysis sheep blood, catalase positive, oxidase negative, non-motile, and ferment lactose, sucrose and ...

  12. Analysis of geminivirus AL2 and L2 proteins reveals a novel AL2 silencing suppressor activity.

    Science.gov (United States)

    Jackel, Jamie N; Buchmann, R Cody; Singhal, Udit; Bisaro, David M

    2015-03-01

    Both posttranscriptional and transcriptional gene silencing (PTGS and TGS, respectively) participate in defense against the DNA-containing geminiviruses. As a countermeasure, members of the genus Begomovirus (e.g., Cabbage leaf curl virus) encode an AL2 protein that is both a transcriptional activator and a silencing suppressor. The related L2 protein of Beet curly top virus (genus Curtovirus) lacks transcription activation activity. Previous studies showed that both AL2 and L2 suppress silencing by a mechanism that correlates with adenosine kinase (ADK) inhibition, while AL2 in addition activates transcription of cellular genes that negatively regulate silencing pathways. The goal of this study was to clarify the general means by which these viral proteins inhibit various aspects of silencing. We confirmed that AL2 inhibits systemic silencing spread by a mechanism that requires transcription activation activity. Surprisingly, we also found that reversal of PTGS and TGS by ADK inactivation depended on whether experiments were conducted in vegetative or reproductive Nicotiana benthamiana plants (i.e., before or after the vegetative-to-reproductive transition). While AL2 was able to reverse silencing in both vegetative and reproductive plants, L2 and ADK inhibition were effective only in vegetative plants. This suggests that silencing maintenance mechanisms can change during development or in response to stress. Remarkably, we also observed that AL2 lacking its transcription activation domain could reverse TGS in reproductive plants, revealing a third, previously unsuspected AL2 suppression mechanism that depends on neither ADK inactivation nor transcription activation. RNA silencing in plants is a multivalent antiviral defense, and viruses respond by elaborating multiple and sometimes multifunctional proteins that inhibit various aspects of silencing. The studies described here add an additional layer of complexity to this interplay. By examining geminivirus AL2 and

  13. Seasonal patterns of mixed species groups in large East African mammals.

    Science.gov (United States)

    Kiffner, Christian; Kioko, John; Leweri, Cecilia; Krause, Stefan

    2014-01-01

    Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk's dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease) of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups.

  14. Coexistence and environmental filtering of species-specific biomass in an African savanna.

    Science.gov (United States)

    Colgan, Matthew S; Asner, Gregory P

    2014-06-01

    Biomass density is a key metric of vegetation abundance, but understanding how community assembly processes, such as environmental filtering and competitive exclusion, affect biomass distributions of coexisting species has proven logistically challenging. Here we apply airborne remote sensing to study the ecosystem-scale distribution of species-specific, woody plant biomass and its relation to topographic and hydrologic gradients in a South African savanna. We also spatially analyzed variation in biomass among species to understand patterns of coexistence, mapping the species and biomass over one million trees across 10500 ha. We found the biomass of dominant woody species to be weakly but significantly related to environmental filters, where a combination of 10 topographic and edaphic variables accounted for community assembly processes in natural ecosystems. Characterizing the species composition of biomass is an important advance in understanding the balance of community assembly processes and its control over current species assemblages.

  15. Desertification and a shift of forest species in the West African Sahel

    Science.gov (United States)

    Gonzalez, Patrick

    2001-01-01

    Original field data show that forest species richness and tree density in the West African Sahel declined in the last half of the 20th century. Average forest species richness of areas of 4 km2 in Northwest Senegal fell from 64 ?? 2 species ca 1945 to 43 ?? 2 species in 1993, a decrease significant at p Sahel species have expanded in the north, tracking a concomitant retraction of mesic Sudan and Guinean species to the south. Multivariate analyses identify latitude and longitude, proxies for rainfall and temperature, as the most significant factors explaining tree and shrub distribution. The changes also decreased human carrying capacity to below actual population densities. The rural population of 45 people km-2 exceeded the 1993 carrying capacity, for firewood from shrubs, of 13 people km-2 (range 1 to 21 people km-2). As an adaptation strategy, ecological and socioeconomic factors favor the natural regeneration of local species over the massive plantation of exotic species. Natural regeneration is a traditional practice in which farmers select small field trees that they wish to raise to maturity, protect them, and prune them to promote rapid growth of the apical meristem. The results of this research provide evidence for desertification in the West African Sahel. These documented impacts of desertification foreshadow possible future effects of climate change.

  16. A geminivirus-based guide RNA delivery system for CRISPR/Cas9 mediated plant genome editing.

    Science.gov (United States)

    Yin, Kangquan; Han, Ting; Liu, Guang; Chen, Tianyuan; Wang, Ying; Yu, Alice Yunzi L; Liu, Yule

    2015-10-09

    CRISPR/Cas has emerged as potent genome editing technology and has successfully been applied in many organisms, including several plant species. However, delivery of genome editing reagents remains a challenge in plants. Here, we report a virus-based guide RNA (gRNA) delivery system for CRISPR/Cas9 mediated plant genome editing (VIGE) that can be used to precisely target genome locations and cause mutations. VIGE is performed by using a modified Cabbage Leaf Curl virus (CaLCuV) vector to express gRNAs in stable transgenic plants expressing Cas9. DNA sequencing confirmed VIGE of endogenous NbPDS3 and NbIspH genes in non-inoculated leaves because CaLCuV can infect plants systemically. Moreover, VIGE of NbPDS3 and NbIspH in newly developed leaves caused photo-bleached phenotype. These results demonstrate that geminivirus-based VIGE could be a powerful tool in plant genome editing.

  17. The C2 Protein from the Geminivirus Tomato Yellow Leaf Curl Sardinia Virus Decreases Sensitivity to Jasmonates and Suppresses Jasmonate-Mediated Defences.

    Science.gov (United States)

    Rosas-Díaz, Tábata; Macho, Alberto P; Beuzón, Carmen R; Lozano-Durán, Rosa; Bejarano, Eduardo R

    2016-01-15

    An increasing body of evidence points at a role of the plant hormones jasmonates (JAs) in determining the outcome of plant-virus interactions. Geminiviruses, small DNA viruses infecting a wide range of plant species worldwide, encode a multifunctional protein, C2, which is essential for full pathogenicity. The C2 protein has been shown to suppress the JA response, although the current view on the extent of this effect and the underlying molecular mechanisms is incomplete. In this work, we use a combination of exogenous hormone treatments, microarray analysis, and pathogen infections to analyze, in detail, the suppression of the JA response exerted by C2. Our results indicate that C2 specifically affects certain JA-induced responses, namely defence and secondary metabolism, and show that plants expressing C2 are more susceptible to pathogen attack. We propose a model in which C2 might interfere with the JA response at several levels.

  18. The C2 Protein from the Geminivirus Tomato Yellow Leaf Curl Sardinia Virus Decreases Sensitivity to Jasmonates and Suppresses Jasmonate-Mediated Defences

    Directory of Open Access Journals (Sweden)

    Tábata Rosas-Díaz

    2016-01-01

    Full Text Available An increasing body of evidence points at a role of the plant hormones jasmonates (JAs in determining the outcome of plant-virus interactions. Geminiviruses, small DNA viruses infecting a wide range of plant species worldwide, encode a multifunctional protein, C2, which is essential for full pathogenicity. The C2 protein has been shown to suppress the JA response, although the current view on the extent of this effect and the underlying molecular mechanisms is incomplete. In this work, we use a combination of exogenous hormone treatments, microarray analysis, and pathogen infections to analyze, in detail, the suppression of the JA response exerted by C2. Our results indicate that C2 specifically affects certain JA-induced responses, namely defence and secondary metabolism, and show that plants expressing C2 are more susceptible to pathogen attack. We propose a model in which C2 might interfere with the JA response at several levels.

  19. Molecular characterization of Babesia and Cytauxzoon species in wild South-African meerkats.

    Science.gov (United States)

    Leclaire, Sarah; Menard, Sandie; Berry, Antoine

    2015-04-01

    Piroplasms, including Babesia, Cytauxzoon and Theileria species, frequently infect domestic and wild mammals. At present, there is no information on the occurrence and molecular identity of these tick-borne blood parasites in the meerkat, one of South Africa's most endearing wildlife celebrities. Meerkats live in territorial groups, which may occur on ranchland in close proximity to humans, pets and livestock. Blood collected from 46 healthy meerkats living in the South-African Kalahari desert was screened by microscopy and molecular methods, using PCR and DNA sequencing of 18S rRNA and ITS1 genes. We found that meerkats were infected by 2 species: one species related to Babesia sp. and one species related to Cytauxzoon sp. Ninety one percent of the meerkats were infected by the Cytauxzoon and/or the Babesia species. Co-infection occurred in 46% of meerkats. The pathogenicity and vectors of these two piroplasm species remains to be determined.

  20. Bemisia tabaci : the whitefly vector of cassava mosaic geminiviruses ...

    African Journals Online (AJOL)

    The ecology of the Bemisia tabaci/cassava/African cassava mosaic virus (ACMV) pathosystem is reviewed briefly with special attention given to the parameters affecting the pattern of population development of B. tabaci. Significant gaps in our understanding of this system remain, particularly concerning the importance of ...

  1. West African pholcid spiders: an overview, with descriptions of five new species (Araneae, Pholcidae

    Directory of Open Access Journals (Sweden)

    Bernhard A. Huber

    2013-10-01

    Full Text Available This paper summarizes current knowledge about West African pholcids. West Africa is here defined as the area south of 17°N and west of 5°E, including mainly the Upper Guinean subregion of the Guineo-Congolian center of endemism. This includes all of Senegal, The Gambia, Guinea Bissau, Guinea, Sierra Leone, Liberia, Ivory Coast, Ghana, Togo and Benin. An annotated list of the 14 genera and 38 species recorded from this area is given, together with distribution maps and an identification key to genera. Five species are newly described: Anansus atewa sp. nov., Artema bunkpurugu sp. nov., Leptopholcus kintampo sp. nov., Spermophora akwamu sp. nov., and S. ziama sp. nov. The female of Quamtana kitahurira is newly described. Additional new records are given for 16 previously described species, including 33 new country records. Distribution patterns of West African pholcids are discussed, as well as possible explanations for relatively low West African pholcid species diversity as compared to Central and East Africa.

  2. Revision of the Indo-Australian species of the genus Phaeochrous castelnau, 1840 (Coleoptera: Scarabaeidae, Hybosorinae), with notes on the African species

    NARCIS (Netherlands)

    Kuijten, P.J.

    1978-01-01

    A revision of the Indo-Australian species and notes on the African species of Phaeochrous are given. Nine new species and three new subspecies are described, viz., Phaeochrous australicus (Australia), compactus (Sri Lanka), elevatus (South India, Sri Lanka), enigmaticus (Java, Bangla Desh, China),

  3. Transcriptional analysis of South African cassava mosaic virus-infected susceptible and tolerant landraces of cassava highlights differences in resistance, basal defense and cell wall associated genes during infection.

    Science.gov (United States)

    Allie, Farhahna; Pierce, Erica J; Okoniewski, Michal J; Rey, Chrissie

    2014-11-20

    Cassava mosaic disease is caused by several distinct geminivirus species, including South African cassava mosaic virus-[South Africa:99] (SACMV). To date, there is limited gene regulation information on viral stress responses in cassava, and global transcriptome profiling in SACMV-infected cassava represents an important step towards understanding natural host responses to plant geminiviruses. A RNA-seq time course (12, 32 and 67 dpi) study, monitoring gene expression in SACMV-challenged susceptible (T200) and tolerant (TME3) cassava landraces, was performed using the Applied Biosystems (ABI) SOLiD next-generation sequencing platform. The multiplexed paired end sequencing run produced a total of 523 MB and 693 MB of paired-end reads for SACMV-infected susceptible and tolerant cDNA libraries, respectively. Of these, approximately 50.7% of the T200 reads and 55.06% of TME3 reads mapped to the cassava reference genome available in phytozome. Using a log2 fold cut-off (pmetabolic pathways, including phenylpropanoid biosynthesis, sucrose and starch metabolism, and plant hormone signalling. Molecular mechanisms for TME3 tolerance are proposed, and differences in patterns and levels of transcriptome profiling between T200 and TME3 with susceptible and tolerant phenotypes, respectively, support the hypothesis that viruses rearrange their molecular interactions in adapting to hosts with different genetic backgrounds.

  4. Evolution of African cassava mosaic virus by recombination between bipartite and monopartite begomoviruses

    Directory of Open Access Journals (Sweden)

    Tiendrébéogo Fidèle

    2012-03-01

    Full Text Available Abstract Background Cassava mosaic disease (CMD is a major constraint on cassava cultivation in Africa. The disease is endemic and is caused by seven distinct cassava mosaic geminiviruses (CMGs, some of them including several variants. Findings From cassava leaf samples presenting CMD symptoms collected in Burkina Faso, four DNA-A begomovirus components were cloned and sequenced, showing 99.9% nucleotide identity among them. These isolates are most closely related to African cassava mosaic virus (ACMV but share less than 89% nucleotide identity (taxonomic threshold with any previously described begomovirus. A DNA-B genomic component, sharing 93% nucleotide identity with DNA-B of ACMV, was also characterized. Since all genomic components have a typical genome organization of Old World bipartite begomoviruses, this new species was provisionally named African cassava mosaic Burkina Faso virus (ACMBFV. Recombination analysis of the new virus demonstrated an interspecies recombinant origin, with major parents related to West African isolates of ACMV, and minor parents related to Tomato leaf curl Cameroon virus and Cotton leaf curl Gezira virus. Conclusion This is the first report of an ACMV-like recombinant begomovirus arisen by interspecific recombination between bipartite and monopartite African begomoviruses.

  5. Uncovering cryptic species diversity of a termite community in a West African savanna.

    Science.gov (United States)

    Hausberger, Barbara; Kimpel, Dorothea; van Neer, Abbo; Korb, Judith

    2011-12-01

    To uncover the termite species diversity of a natural African savanna ecosystem, we combined morphological analyses and sequencing of three gene fragments (cytochrome oxidase I, cytochrome oxidase II and 28SrDNA, total length about 2450 bp) to infer putative species from phylogenetic trees. We identified 18 putative species clusters with high support values and which we retrieved consistently. Samples from two genera (Ancistrotermes and Microcerotermes) were excluded from the mitochondrial phylogenetic analyses as they might represent nuclear mitochondrial sequences (NUMTs). In total, our data suggest a species richness of at least 20 species, all but one belonging to the Termitidae (higher termites), and among them the fungus-growing Macrotermitinae were most prevalent with at least nine putative species. Within the fungus-growers the most species-rich genus was Microtermes and its four putative species were all cryptic species. Their abundance in the samples suggests that they play an important ecological role which is completely unstudied also due to the lack of reliable identification means. Our study shows that morphological traits are unreliable means of species identification for several termite taxa. Yet reliable and consistent identification is necessary for studying the functional role of termites in ecosystem and global processes. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. A third species of Polyspatha, an endemic African genus of Commelinaceae

    Directory of Open Access Journals (Sweden)

    Robert Faden

    2011-05-01

    Full Text Available Polyspatha oligospatha Faden, the third species in a small African endemic genus of Commelinaceae, is described.  It is widespread but has been overlooked because of its small stature and resemblance to small plants of P. paniculata.  It differs from both P. paniculata and P. hirsuta, the two other species, by its leaf pubescence, fewer, more widely spaced and usually patent spathes, deeply ridged seeds with numerous knobby, transversely interrupted ridges, and morning anthesis.  It occurs throughout the Congolian forests from Cameroon to Uganda, but it is also disjunct in Ivory Coast, across the Dahomey gap.

  7. Seasonal patterns of mixed species groups in large East African mammals.

    Directory of Open Access Journals (Sweden)

    Christian Kiffner

    Full Text Available Mixed mammal species groups are common in East African savannah ecosystems. Yet, it is largely unknown if co-occurrences of large mammals result from random processes or social preferences and if interspecific associations are consistent across ecosystems and seasons. Because species may exchange important information and services, understanding patterns and drivers of heterospecific interactions is crucial for advancing animal and community ecology. We recorded 5403 single and multi-species clusters in the Serengeti-Ngorongoro and Tarangire-Manyara ecosystems during dry and wet seasons and used social network analyses to detect patterns of species associations. We found statistically significant associations between multiple species and association patterns differed spatially and seasonally. Consistently, wildebeest and zebras preferred being associated with other species, whereas carnivores, African elephants, Maasai giraffes and Kirk's dik-diks avoided being in mixed groups. During the dry season, we found that the betweenness (a measure of importance in the flow of information or disease of species did not differ from a random expectation based on species abundance. In contrast, in the wet season, we found that these patterns were not simply explained by variations in abundances, suggesting that heterospecific associations were actively formed. These seasonal differences in observed patterns suggest that interspecific associations may be driven by resource overlap when resources are limited and by resource partitioning or anti-predator advantages when resources are abundant. We discuss potential mechanisms that could drive seasonal variation in the cost-benefit tradeoffs that underpin the formation of mixed-species groups.

  8. Identification of Host Genes Involved in Geminivirus Infection Using a Reverse Genetics Approach

    Science.gov (United States)

    Luna, Ana P.; Bejarano, Eduardo R.

    2011-01-01

    Geminiviruses, like all viruses, rely on the host cell machinery to establish a successful infection, but the identity and function of these required host proteins remain largely unknown. Tomato yellow leaf curl Sardinia virus (TYLCSV), a monopartite geminivirus, is one of the causal agents of the devastating Tomato yellow leaf curl disease (TYLCD). The transgenic 2IRGFP N. benthamiana plants, used in combination with Virus Induced Gene Silencing (VIGS), entail an important potential as a tool in reverse genetics studies to identify host factors involved in TYLCSV infection. Using these transgenic plants, we have made an accurate description of the evolution of TYLCSV replication in the host in both space and time. Moreover, we have determined that TYLCSV and Tobacco rattle virus (TRV) do not dramatically influence each other when co-infected in N. benthamiana, what makes the use of TRV-induced gene silencing in combination with TYLCSV for reverse genetic studies feasible. Finally, we have tested the effect of silencing candidate host genes on TYLCSV infection, identifying eighteen genes potentially involved in this process, fifteen of which had never been implicated in geminiviral infections before. Seven of the analyzed genes have a potential anti-viral effect, whereas the expression of the other eleven is required for a full infection. Interestingly, almost half of the genes altering TYLCSV infection play a role in postranslational modifications. Therefore, our results provide new insights into the molecular mechanisms underlying geminivirus infections, and at the same time reveal the 2IRGFP/VIGS system as a powerful tool for functional reverse genetics studies. PMID:21818318

  9. Petrocephalus boboto and Petrocephalus arnegardi, two new species of African electric fish (Osteoglossomorpha, Mormyridae) from the Congo River basin

    OpenAIRE

    Lavoué, Sébastien; Sullivan, John P.

    2014-01-01

    Abstract A specimen of the African weakly electric fish genus Petrocephalus (Osteoglossomorpha, Mormyridae) collected in the Congo River at Yangambi, Orientale Province, Democratic Republic of Congo, is described as a new species. Petrocephalus boboto sp. n. can be distinguished from other Central African species of Petrocephalus by a combination of the following characteristics: three distinct black spots on the body, one at the origin of the pectoral fin, one at the origin of the caudal fin...

  10. Análisis de la infección por geminivirus en plantas con la maquinaria de metilación del DNA alterada.

    OpenAIRE

    Piedra-Aguilera, Alvaro; Rodríguez-Negrete, Edgar; Bejarano, Eduardo R.; Castillo, Araceli G.

    2015-01-01

    Los geminivirus son virus de plantas pertenecientes a la familia Geminiviridae. Poseen un genoma compuesto por una o dos moléculas de DNA circular de cadena simple y una cápside compuesta de 2 partes icosaédricas gemelas, de ahí el nombre de geminivirus. Uno de los geminivirus más estudiados es el virus del rizado amarillo de la hoja de tomate (TYLCV, Tomato yellow leaf curl virus), causante de importantes pérdidas en las cosechas en zonas templadas, subtropicales y tropicales. Este geminivir...

  11. Traditional uses, phytochemistry and pharmacological properties of African Nauclea species: A review.

    Science.gov (United States)

    Haudecoeur, Romain; Peuchmaur, Marine; Pérès, Basile; Rome, Maxime; Taïwe, Germain Sotoing; Boumendjel, Ahcène; Boucherle, Benjamin

    2018-02-15

    The genus Nauclea in Africa comprises seven species. Among them, N. latifolia, N. diderrichii and N. pobeguinii are widely used by the local population in traditional remedies. Preparation from various parts of plants (e.g. roots, bark, leaves) are indicated by traditional healers for a wide range of diseases including malaria, pain, digestive ailments or metabolic diseases. A literature search was conducted on African species of the genus Nauclea using scientific databases such as Google Scholar, Pubmed or SciFinder. Every document of ethnopharmacological, phytochemical or pharmacological relevance and written in English or French were analyzed. The Nauclea genus is used as ethnomedicine all along sub-Saharan Africa. Several local populations consider Nauclea species as a major source of remedies for malaria. In this regard, two improved traditional medicines are currently under development using extracts from N. latifolia and N. pobeguinii. Concerning the chemical composition of the Nauclea genus, indoloquinolizidines alkaloids could be considered as the major class of compounds as they are reported in every analyzed Nauclea species, with numerous structures identified. Based on traditional indications a considerable amount of pharmacological studies were conducted to ensure activity and attempt to link them to the presence of particular compounds in plant extracts. Many experimental studies using plant extracts of the African species of the genus Nauclea validate traditional indications (e.g. malaria and pain). However, bioactive compounds are rarely identified and therefore, there is a clear need for further evaluations as well as for toxicity experiments. The sustainability of these plants, especially of N. diderrichii, a threatened species, should be kept in mind to adapt local uses and preparation modes of traditional remedies. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. A taxonomic revision of the southern African native and naturalized species of Silene L. (Caryophyllaceae

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2012-12-01

    Full Text Available The native and naturalized species of Silene L. in southern Africa are reviewed, with full synonomy and the description of two new species from the West Coast of Western Cape. Eight native species and three naturalized species are recognized, including the first identification in southern Africa of the Mediterranean S. nocturna L. The identity of S. aethiopica Burm., which has remained unknown since its description, is established and is found to be the oldest name for S. clandestina Jacq. Patterns of morphological variation within each species are discussed and subspecies are recognized for geographically segregated groups of populations that are ± morphologically diagnosable. The following new names or combinations are made among the southern African taxa: S. aethiopica subsp. longiflora; S. burchellii subsp. modesta, subsp. multiflora, and subsp. pilosellifolia; S. crassifolia subsp. primuliflora; S. saldanhensis; S. rigens; and S. undulata subsp. polyantha. Each taxon is described, with information on ecology and distribution, and most species are illustrated, including SEM micrographs of the seeds.

  13. Animal African Trypanosomiasis: Time to Increase Focus on Clinically Relevant Parasite and Host Species.

    Science.gov (United States)

    Morrison, Liam J; Vezza, Laura; Rowan, Tim; Hope, Jayne C

    2016-08-01

    Animal African trypanosomiasis (AAT), caused by Trypanosoma congolense and Trypanosoma vivax, remains one of the most important livestock diseases in sub-Saharan Africa, particularly affecting cattle. Despite this, our detailed knowledge largely stems from the human pathogen Trypanosoma brucei and mouse experimental models. In the postgenomic era, the genotypic and phenotypic differences between the AAT-relevant species of parasite or host and their model organism counterparts are increasingly apparent. Here, we outline the timeliness and advantages of increasing the research focus on both the clinically relevant parasite and host species, given that improved tools and resources for both have been developed in recent years. We propose that this shift of emphasis will improve our ability to efficiently develop tools to combat AAT. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. ANATOMICAL CHARACTERISTICS AND WOOD PHYSICAL- MECHANICAL PROPERTIES OF TWO AFRICAN MAHOGANY SPECIES

    Directory of Open Access Journals (Sweden)

    Tâmara Suely Filgueira Amorim França

    2015-12-01

    Full Text Available The objective of this study was to evaluate the anatomical characteristics and wood physical-mechanical properties of two African mahogany species (Khaya ivorensis and Khaya senegalensis. Five trees of each species with 19-years-old, proceeding from experimental parcels in the areas of the Reserva Natural Vale, located in Sooretama, Espírito Santo State, Brazil. For the anatomical characteristics samples were taken at the position of transition between heartwood and sapwood (peripheral heart. In the evaluation of the specific density were used two opposing wedges from discs gotten in the corresponding region to the diameter the height of the breast (DHB, taken the 1,30 m of the ground, and in positions 0, 25, 50, 75 and 100% of the commercial height of the tree. For shrinkage 20 samples obtained randomly throughout the trunk of each species. The mechanical tests were carried through in removed samples of the central large plank, to the discarded the pith. The species were different how much to the type and frequency of vases and porosity. Rays were predominantly multiseriates, heterocellulars and fibers are libriform. The wood of Khaya ivorensis has low specific density and wood of Khaya senegalensis has medium specific density. The two wood species have normal dimensional stability. In relation the mechanical properties, the Khaya senegalensis wood had the biggest values for all the carried through tests.

  15. Geological substrates shape tree species and trait distributions in African moist forests.

    Science.gov (United States)

    Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie

    2012-01-01

    Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km(2) spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced differences in population and ecosystem processes, and call for different

  16. Geological substrates shape tree species and trait distributions in African moist forests.

    Directory of Open Access Journals (Sweden)

    Adeline Fayolle

    Full Text Available Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii identify potential mechanisms explaining distribution patterns through a trait-based approach.We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km(2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology and historical factors (human disturbance were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata.The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced differences in population and ecosystem processes, and call for

  17. Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests

    Science.gov (United States)

    Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie

    2012-01-01

    Background Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced

  18. Effects of Climate and Land Use on Herbaceous Species Richness and Vegetation Composition in West African Savanna Ecosystems

    OpenAIRE

    Zerbo, Issouf; Bernhardt-Römermann, Markus; Ouédraogo, Oumarou; Hahn, Karen; Thiombiano, Adjima

    2016-01-01

    West African Savanna ecosystems are undergoing severe changes in their vegetation composition due to the impact of human land use and changes in climatic conditions. This study aims to examine the effect of climate, land use, and their interaction on species richness and composition of West African herbaceous vegetation. Plot based vegetation sampling was done in Burkina Faso. Specific richness and diversity indices were used to determine the effect of land use, climate, and their interaction...

  19. Multivariate analysis as a key tool in chemotaxonomy of brinjal eggplant, African eggplants and wild related species.

    Science.gov (United States)

    Haliński, Łukasz P; Samuels, John; Stepnowski, Piotr

    2017-12-01

    The brinjal eggplant (Solanum melongena L.) is an important vegetable species worldwide, while African eggplants (S. aethiopicum L., S. macrocarpon L.) are indigenous vegetable species of local significance. Taxonomy of eggplants and their wild relatives is complicated and still unclear. Hence, the objective of the study was to clarify taxonomic position of cultivars and landraces of brinjal, its wild relatives and African eggplant species and their wild ancestors using chemotaxonomic markers and multivariate analysis techniques for data processing, with special attention paid to the recognition of markers characteristic for each group of the plants. The total of 34 accessions belonging to 9 species from genus Solanum L. were used in the study. Chemotaxonomic analysis was based on the profiles of cuticular n-alkanes and methylalkanes, obtained using gas chromatography-mass spectrometry and gas chromatography with flame ionization detector. Standard hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used for the classification, while the latter and two-way HCA allowed to identify markers responsible for the clustering of the species. Cultivars, landraces and wild forms of S. melongena were practically identical in terms of their taxonomic position. The results confirmed high and statistically significant distinctiveness of all African eggplant species from the brinjal eggplant. The latter was characterized mostly by abundant long chain hydrocarbons in the range of 34-37 carbon atoms. The differences between both African eggplant species were, however, also statistically significant; S. aethiopicum displayed the highest contribution of 2-methylalkanes to the total cuticular hydrocarbons, while S. macrocarpon was characterized by elevated n-alkanes in the range of 25-32 carbon atoms. Wild ancestors of both African eggplant species were identical with their cultivated relatives. Concluding, high usefulness of the chemotaxonomic

  20. The African Crane Database (1978-2014): Records of three threatened crane species (Family: Gruidae) from southern and eastern Africa.

    Science.gov (United States)

    Smith, Tanya; Page-Nicholson, Samantha; Morrison, Kerryn; Gibbons, Bradley; Jones, M Genevieve W; van Niekerk, Mark; Botha, Bronwyn; Oliver, Kirsten; McCann, Kevin; Roxburgh, Lizanne

    2016-01-01

    The International Crane Foundation (ICF) / Endangered Wildlife Trust's (EWT) African Crane Conservation Programme has recorded 26 403 crane sightings in its database from 1978 to 2014. This sightings collection is currently ongoing and records are continuously added to the database by the EWT field staff, ICF/EWT Partnership staff, various partner organizations and private individuals. The dataset has two peak collection periods: 1994-1996 and 2008-2012. The dataset collection spans five African countries: Kenya, Rwanda, South Africa, Uganda and Zambia; 98% of the data were collected in South Africa. Georeferencing of the dataset was verified before publication of the data. The dataset contains data on three African crane species: Blue Crane Anthropoides paradiseus , Grey Crowned Crane Balearica regulorum and Wattled Crane Bugeranus carunculatus . The Blue and Wattled Cranes are classified by the IUCN Red List of Threatened Species as Vulnerable and the Grey Crowned Crane as Endangered. This is the single most comprehensive dataset published on African Crane species that adds new information about the distribution of these three threatened species. We hope this will further aid conservation authorities to monitor and protect these species. The dataset continues to grow and especially to expand in geographic coverage into new countries in Africa and new sites within countries. The dataset can be freely accessed through the Global Biodiversity Information Facility data portal.

  1. Tree Density and Species Decline in the African Sahel Attributable to Climate

    Science.gov (United States)

    Gonzalez, Patrick; Tucker, Compton J.; Sy, H.

    2012-01-01

    Increased aridity and human population have reduced tree cover in parts of the African Sahel and degraded resources for local people. Yet, tree cover trends and the relative importance of climate and population remain unresolved. From field measurements, aerial photos, and Ikonos satellite images, we detected significant 1954-2002 tree density declines in the western Sahel of 18 +/- 14% (P = 0.014, n = 204) and 17 +/- 13% (P = 0.0009, n = 187). From field observations, we detected a significant 1960-2000 species richness decline of 21 +/- 11% (P = 0.0028, n = 14) across the Sahel and a southward shift of the Sahel, Sudan, and Guinea zones. Multivariate analyses of climate, soil, and population showed that temperature most significantly (P Sahel climate variability, particularly the significant (P Sahel tree cover changes to global climate change. This suggests roles for global action and local adaptation to address ecological change in the Sahel.

  2. The South African fruit fly action plan: area-wide suppression and exotic species surveillance

    International Nuclear Information System (INIS)

    Barnes, Brian N.; Venter, Jan-Hendrik

    2006-01-01

    Two species of tephritid fruit flies of economic importance, Mediterranean fruit fly (Medfly, Ceratitis capitata [Wiedemann]) and Natal fruit fly (C. rosa Karsch) cause economic losses in the South African deciduous fruit industry of approximately US$3 million per annum. A third species, marula fruit fly, C. cosyra (Walker), causes damage to citrus and sub-tropical fruits in the north-eastern part of the country. In 1999 a sterile insect technique (SIT) programme against Medfly was initiated over 10,000 ha of table grapes with a goal of cost-effective, ecologically compatible suppression of Medfly. The SIT programme was extended to two other fruit production areas in 2004. Although results in all three SIT areas have been mixed, populations of wild Medflies, as well as associated pesticide usage and control costs, have been reduced since the start of sterile fly releases. Reasons for the partial degree of success and the relatively slow expansion of Medfly SIT to other areas include economic, operational and cultural factors, as well as certain fruit production practices. Before fruit fly-free areas can be created, deficiencies in the ability to mass-rear Natal fruit fly need to be overcome so that an SIT programme against this species can be initiated. Any fruit fly suppression or eradication campaign will be severely compromised by any introductions into South Africa of exotic fruit fly species. The risk of such introductions is increasing as trade with and travel to the country increases. A Plant Health Early Warning Systems Division has been initiated to formulate fruit fly detection and action plans. Melon fly (Bactrocera cucurbitae [Coquillett]), Asian fruit fly (B. invadens Drew, Tsurutu and White) and peach fruit fly (B. zonata [Saunders]), which are all well established in parts of Africa and/or Indian Ocean islands, have been identified as presenting the highest risk for entering and becoming established in South Africa. An exotic fruit fly surveillance

  3. The South African fruit fly action plan: area-wide suppression and exotic species surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Brian N., E-mail: barnesb@arc.agric.z [ARC Infruitec-Nietvoorbij Institute for Fruit, Vine and Wine, Stellenbosch (South Africa); Venter, Jan-Hendrik, E-mail: janhendrikv@nda.agric.z [Directorate Plant Health, Pretoria (South Africa)

    2006-07-01

    Two species of tephritid fruit flies of economic importance, Mediterranean fruit fly (Medfly, Ceratitis capitata [Wiedemann]) and Natal fruit fly (C. rosa Karsch) cause economic losses in the South African deciduous fruit industry of approximately US$3 million per annum. A third species, marula fruit fly, C. cosyra (Walker), causes damage to citrus and sub-tropical fruits in the north-eastern part of the country. In 1999 a sterile insect technique (SIT) programme against Medfly was initiated over 10,000 ha of table grapes with a goal of cost-effective, ecologically compatible suppression of Medfly. The SIT programme was extended to two other fruit production areas in 2004. Although results in all three SIT areas have been mixed, populations of wild Medflies, as well as associated pesticide usage and control costs, have been reduced since the start of sterile fly releases. Reasons for the partial degree of success and the relatively slow expansion of Medfly SIT to other areas include economic, operational and cultural factors, as well as certain fruit production practices. Before fruit fly-free areas can be created, deficiencies in the ability to mass-rear Natal fruit fly need to be overcome so that an SIT programme against this species can be initiated. Any fruit fly suppression or eradication campaign will be severely compromised by any introductions into South Africa of exotic fruit fly species. The risk of such introductions is increasing as trade with and travel to the country increases. A Plant Health Early Warning Systems Division has been initiated to formulate fruit fly detection and action plans. Melon fly (Bactrocera cucurbitae [Coquillett]), Asian fruit fly (B. invadens Drew, Tsurutu and White) and peach fruit fly (B. zonata [Saunders]), which are all well established in parts of Africa and/or Indian Ocean islands, have been identified as presenting the highest risk for entering and becoming established in South Africa. An exotic fruit fly surveillance

  4. Phylogeography of SW Mediterranean firs: different European origins for the North African Abies species.

    Science.gov (United States)

    Sánchez-Robles, Jose M; Balao, Francisco; Terrab, Anass; García-Castaño, Juan L; Ortiz, María A; Vela, Errol; Talavera, Salvador

    2014-10-01

    The current distribution of Western Mediterranean Abies species is a result of complex geodynamic processes and climatic oscillations that occurred in the past. Abies sect. Piceaster offers a good study model to explore how geo-climatic oscillations might have influenced its expansion and diversification on both sides of the W Mediterranean basin. We investigated the genetic variation within and among nine populations from five Abies species by molecular markers with high and low mutation rates and contrasting inheritance (AFLP and cpSSR). Analyses revealed the opening of the Strait of Gibraltar as an effective barrier against gene flow between the Southern Iberian (A. pinsapo) and North African (A. marocana and A. tazaotana) firs. The A. pinsapo populations in Spain and likewise those of the A. marocana - A. tazaotana population complex were not differentiated, and no evidence was found to distinguish A. tazaotana at the species level. Diversification of Abies across North Africa could occur by way of at least two vicariant events from Europe, in the west, giving rise to the A. marocana - A. tazaotana complex, and in the east, giving A. numidica. Secondary contacts among species from Abies sect. Piceaster (A. pinsapo and A. numidica), and with A. alba (Abies sect. Abies) are also indicated. However, there is a closer relationship between the Algerian fir (A. numidica) and the North Mediterranean widespread A. alba, than with the Moroccan firs (A. marocana and A. tazaotana) or the Southern Iberian (A. pinsapo). We also discuss the distribution range of these taxa in its paleogeological and paleoclimatic context, and propose that part of the modern geography of the South-Western Mediterranean firs might be traced back to the Tertiary. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species.

    Science.gov (United States)

    Venter, Gert J; Labuschagne, Karien; Boikanyo, Solomon N B; Morey, Liesl

    2014-08-08

    The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae) should form part of an integrated control programme to combat African horse sickness and other diseases transmitted by these blood-feeding midges. In the present study the repellent effects of a commercially available mosquito repellent, a combination of citronella and lemon eucalyptus oils, on Culicoides midges was determined. The number of midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white light tubes and baited with peel-stick patches, each containing 40 mg of active ingredient, was compared with that of two unbaited traps. Two trials were conducted and in each trial the four traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Although more midges were collected in the baited traps, the mean number in the baited and unbaited traps was not significantly different. This mosquito repellent did not influence either the species composition or the physiological groups of Culicoides imicola Kieffer. The higher mean numbers in the baited traps, although not statistically significant, may indicate that this mosquito repellent might even attract Culicoides midges under certain conditions.

  6. Diversity of Dicotyledenous-Infecting Geminiviruses and Their Associated DNA Molecules in Southern Africa, Including the South-West Indian Ocean Islands

    Directory of Open Access Journals (Sweden)

    Lindy L. Esterhuizen

    2012-09-01

    Full Text Available The family Geminiviridae comprises a group of plant-infecting circular ssDNA viruses that severely constrain agricultural production throughout the temperate regions of the world, and are a particularly serious threat to food security in sub-Saharan Africa. While geminiviruses exhibit considerable diversity in terms of their nucleotide sequences, genome structures, host ranges and insect vectors, the best characterised and economically most important of these viruses are those in the genus Begomovirus. Whereas begomoviruses are generally considered to be either monopartite (one ssDNA component or bipartite (two circular ssDNA components called DNA-A and DNA-B, many apparently monopartite begomoviruses are associated with additional subviral ssDNA satellite components, called alpha- (DNA-as or betasatellites (DNA-βs. Additionally, subgenomic molecules, also known as defective interfering (DIs DNAs that are usually derived from the parent helper virus through deletions of parts of its genome, are also associated with bipartite and monopartite begomoviruses. The past three decades have witnessed the emergence and diversification of various new begomoviral species and associated DI DNAs, in southern Africa, East Africa, and proximal Indian Ocean islands, which today threaten important vegetable and commercial crops such as, tobacco, cassava, tomato, sweet potato, and beans. This review aims to describe what is known about these viruses and their impacts on sustainable production in this sensitive region of the world.

  7. Concordant genetic structure in two species of woodpecker distributed across the primary West African biogeographic barriers.

    Science.gov (United States)

    Fuchs, Jérôme; Bowie, Rauri C K

    2015-07-01

    The lowland forests of western and central tropical Africa are separated by several potential biogeographic barriers to dispersal for forest adapted vertebrates. The two primary barriers are (1) the Dahomey Gap, a savanna corridor that reaches the coast of southern Ghana, Togo and Benin, and separates the West African rainforest into the Upper (Ghana west to Guinea) and Lower Guinea (Nigeria to Uganda and Angola) forest blocks, and (2) the Lower Niger River, a large delta that separates Western and Eastern Nigeria. Previous studies on terrestrial vertebrates (lizards, mammals and birds) have highlighted a genetic break in the Dahomey Gap/Lower Niger River area although the relative importance of each barrier has not been assessed due to limitations in geographic sampling. We compared the phylogeographic history of two co-distributed sister-species of woodpeckers (Campethera caroli and C. nivosa) using data from three loci representing all inheritance modes. Our analyses revealed that both the Dahomey Gap and possibly the Lower Niger River acted as strong biogeographic barriers for the two woodpecker species, with the Lower Niger River being the first barrier to have formed, leading to three distinct populations of C. nivosa. Our divergence time analyses revealed that both these biogeographic barriers formed during the Pleistocene, supporting the Pleistocene refuge hypothesis, with the Dahomey Gap likely appearing about 0.5 myr BP. No genetic structure was recovered among sampled populations in either the Upper or the Lower Guinea Forest Block for both species, despite the considerable geographic area covered. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Demography of woody species in a semi-arid African savanna reserve following the re-introduction of elephants

    Science.gov (United States)

    O'Connor, Timothy G.

    2017-01-01

    The hypothesis that African elephants may cause the local extirpation of selected woody species was evaluated in a medium-sized, semi-arid reserve following their reintroduction at low density. Mortality, state-change, and regeneration of 25 tree and 17 shrub species were studied between 1997 and 2010. Annual mortality of shrub species ranged from 0.2 to 8.0%, with six species experiencing 6-8%. Eight shrub species lost more than half their adult population (range 10-94%). Annual tree mortality ranged from 0.2 to 10.5%. The two dominant dryland tree species experienced Elephants accounted for >63% and stress-related agents >20% of tree deaths. The manner in which elephants induced tree death depended on species. The proportion of individuals of a species killed by pollarding or uprooting ranged from 0 to 74%, and by debarking from 0 to 100%. Complete uprooting was a common cause of death for three shrub species. Regeneration ranged from zero for six tree and one shrub species to a seedling every 7 m2 for Colophospermum mopane and 23 m2 for Dichrostachys cinerea in riparian habitat. Three shrub and eight tree species were identified as vulnerable to local extirpation owing to a combination of high mortality and poor regeneration that is likely to result in a considerably simplified system. Reintroduction of elephants into medium-sized reserves without regulation of their numbers may not be a desirable action.

  9. Taxonomy of Atlantic Central African orchids 5. A new species of Angraecum sect. Conchoglossum (Orchidaceae, Angraecinae) from Gabon and Cameroon.

    Science.gov (United States)

    Ječmenica, Vladimir; Droissart, Vincent; Noret, Nausicaa; Stévart, Tariq

    2016-01-01

    Recent field inventories and taxonomic research in Central Africa have resulted in the discovery of many new orchid species. Five specimens of an apparently new Angraecum species were collected in Gabon and Cameroon. They stand out for their hanging habit and short zig-zag stem. Morphology of leaves and habit is somewhat comparable to Angraecum cultriforme and Angraecum stolzii, two species from East Africa. Flowers of the novelty share the general morphology of Angraecum pyriforme from which the new species is distinguished by being smaller and with a different lip-spur ratio. Here we show that these five specimens represent a new species, described here as Angraecum lanceolatum. The distinguishing traits include thin lanceolate leaves, convolute distally, with a rhombic lip shape. Dichotomous key to four Central African species of sect. Conchoglossum and a table of the diagnostic characters of the seven related Continental African Angraecum taxa are included here. A preliminary assessment of the conservation status of Angraecum lanceolatum is provided, using the IUCN Red List Categories and Criteria.

  10. Paralyzing action from a distance in an arboreal African ant species.

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    Aline Rifflet

    Full Text Available Due to their prowess in interspecific competition and ability to catch a wide range of arthropod prey (mostly termites with which they are engaged in an evolutionary arms race, ants are recognized as a good model for studying the chemicals involved in defensive and predatory behaviors. Ants' wide diversity of nesting habits and relationships with plants and prey types implies that these chemicals are also very diverse. Using the African myrmicine ant Crematogaster striatula as our focal species, we adopted a three-pronged research approach. We studied the aggressive and predatory behaviors of the ant workers, conducted bioassays on the effect of their Dufour gland contents on termites, and analyzed these contents. (1 The workers defend themselves or eliminate termites by orienting their abdominal tip toward the opponent, stinger protruded. The chemicals emitted, apparently volatile, trigger the recruitment of nestmates situated in the vicinity and act without the stinger having to come into direct contact with the opponent. Whereas alien ants competing with C. striatula for sugary food sources are repelled by this behavior and retreat further and further away, termites defend their nest whatever the danger. They face down C. striatula workers and end up by rolling onto their backs, their legs batting the air. (2 The bioassays showed that the toxicity of the Dufour gland contents acts in a time-dependent manner, leading to the irreversible paralysis, and, ultimately, death of the termites. (3 Gas chromatography-mass spectrometry analyses showed that the Dufour gland contains a mixture of mono- or polyunsaturated long-chain derivatives, bearing functional groups like oxo-alcohols or oxo-acetates. Electrospray ionization-mass spectrometry showed the presence of a molecule of 1584 Da that might be a large, acetylated alkaloid capable of splitting into smaller molecules that could be responsible for the final degree of venom toxicity.

  11. Development of a gene silencing DNA vector derived from a broad host range geminivirus

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    Hancock Leandria C

    2009-07-01

    Full Text Available Abstract Background Gene silencing is proving to be a powerful tool for genetic, developmental, and physiological analyses. The use of viral induced gene silencing (VIGS offers advantages to transgenic approaches as it can be potentially applied to non-model systems for which transgenic techniques are not readily available. However, many VIGS vectors are derived from Gemini viruses that have limited host ranges. We present a new, unipartite vector that is derived from a curtovirus that has a broad host range and will be amenable to use in many non-model systems. Results The construction of a gene silencing vector derived from the geminivirus Beet curly top virus (BCTV, named pWSRi, is reported. Two versions of the vector have been developed to allow application by biolistic techniques or by agro-infiltration. We demonstrate its ability to silence nuclear genes including ribulose bisphosphate carboxylase small subunit (rbcS, transketolase, the sulfur allele of magnesium chelatase (ChlI, and two homeotic transcription factors in spinach or tomato by generating gene-specific knock-down phenotypes. Onset of phenotypes occurred 3 to 12 weeks post-inoculation, depending on the target gene, in organs that developed after the application. The vector lacks movement genes and we found no evidence for significant spread from the site of inoculation. However, viral amplification in inoculated tissue was detected and is necessary for systemic silencing, suggesting that signals generated from active viral replicons are efficiently transported within the plant. Conclusion The unique properties of the pWSRi vector, the ability to silence genes in meristem tissue, the separation of virus and silencing phenotypes, and the broad natural host range of BCTV, suggest that it will have wide utility.

  12. New records of Pennatulacea (Anthozoa: Octocorallia from the African Atlantic coast, with description of a new species and a zoogeographic analysis

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    Pablo J. López-González

    2001-03-01

    Full Text Available A collection of pennatulaceans from ten cruises, acquired between 1982 and 1989 from off the western African coast comprises ca. 350 specimens of 13 species. One of the cruise is from the Gulf of Guinea and eight from the Southeast Atlantic. Fifty-four stations were sampled from depths of 91-1112 m. One previously undescribed species in the genus Stylatula is reported and described as new from samples collected from the Namibian continental shelf. Considering these collections, and previous records, the pennatulaceans in the western African region show biogeographic affinities with three geographic areas: West Africa (55.5% of the species, which comprises the Canary, Gulf of Guinea, and Benguela regions; the North Atlantic (3.7% of the species, which represents the more widespread Atlantic taxa; and Cape Endemic (7.4% of the species, which comprises the southern African region.

  13. Veinte años de investigación con Geminivirus en vegetales en Guanajuato Veinte años de investigación con Geminivirus en vegetales en Guanajuato

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    Diana Lilia Trejo Saavedra

    2012-02-01

    Full Text Available   Virology is an important science because viral diseases affect direct or indirectly to human kind. There are several families of plant viruses infecting important crops. Among those, the family Geminiviridae has become an important problem since cause serious damages around the world. In Mexico, the presence of geminiviruses was reported in the late 70’s. Because their importance, the members of the Plant Virology Laboratory at Cinvestav Irapuato have been interested in generating useful information to propose strategies for geminivirus control. Here, we summarized 20 years of research in geminivirology in our laboratory. Another intention was to show how the advances in other research areas such as microbiology, physics, biochemistry, molecular biology and more recently bioinformatics could contribute to our knowledge and understanding of geminivirus. La virología es una ciencia muy importante, debido a que los virus perjudican los intereses del hombre, ya sea directamente afectando su salud o indirectamente infectando sus cultivos, su ganado o sus mascotas. Entre las familias de virus que infectan plantas destaca la familia Geminiviridae, convertida en un serio problema en el mundo. En México la presencia de estos virus fue reportada a finales de la década de los 70s. Debido a que causan grandes pérdidas agronómicas, el grupo de virología vegetal del Cinvestav Irapuato inició su estudio a finales de los 80s con la intención de poder proponer estrategias de solución. Nuestra intención en este ensayo es, además de hacer una recapitulación de las investigaciones realizadas en los últimos 20 años, mostrar como el avance de una ciencia (virología se ve influenciada por los avances en otras ramas como la microbiología, física, bioquímica, biología molecular y más recientemente la bioinformática.

  14. Diversity and species composition of West African ungulate assemblages: effects of fire, climate and soil

    NARCIS (Netherlands)

    Klop, L.F.; Prins, H.H.T.

    2008-01-01

    Aim Anthropogenic fires are a major component of the ecology of rangelands throughout the world. To assess the effects of these fires on the diversity patterns of herbivores, we related gradients in fire occurrence, climate and soil fertility to patterns in alpha and beta diversity of African

  15. Primary and secondary siRNAs in geminivirus-induced gene silencing.

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    Michael Aregger

    2012-09-01

    Full Text Available In plants, RNA silencing-based antiviral defense is mediated by Dicer-like (DCL proteins producing short interfering (siRNAs. In Arabidopsis infected with the bipartite circular DNA geminivirus Cabbage leaf curl virus (CaLCuV, four distinct DCLs produce 21, 22 and 24 nt viral siRNAs. Using deep sequencing and blot hybridization, we found that viral siRNAs of each size-class densely cover the entire viral genome sequences in both polarities, but highly abundant siRNAs correspond primarily to the leftward and rightward transcription units. Double-stranded RNA precursors of viral siRNAs can potentially be generated by host RDR-dependent RNA polymerase (RDR. However, genetic evidence revealed that CaLCuV siRNA biogenesis does not require RDR1, RDR2, or RDR6. By contrast, CaLCuV derivatives engineered to target 30 nt sequences of a GFP transgene by primary viral siRNAs trigger RDR6-dependent production of secondary siRNAs. Viral siRNAs targeting upstream of the GFP stop codon induce secondary siRNAs almost exclusively from sequences downstream of the target site. Conversely, viral siRNAs targeting the GFP 3'-untranslated region (UTR induce secondary siRNAs mostly upstream of the target site. RDR6-dependent siRNA production is not necessary for robust GFP silencing, except when viral siRNAs targeted GFP 5'-UTR. Furthermore, viral siRNAs targeting the transgene enhancer region cause GFP silencing without secondary siRNA production. We conclude that the majority of viral siRNAs accumulating during geminiviral infection are RDR1/2/6-independent primary siRNAs. Double-stranded RNA precursors of these siRNAs are likely generated by bidirectional readthrough transcription of circular viral DNA by RNA polymerase II. Unlike transgenic mRNA, geminiviral mRNAs appear to be poor templates for RDR-dependent production of secondary siRNAs.

  16. Primary and secondary siRNAs in geminivirus-induced gene silencing.

    Science.gov (United States)

    Aregger, Michael; Borah, Basanta K; Seguin, Jonathan; Rajeswaran, Rajendran; Gubaeva, Ekaterina G; Zvereva, Anna S; Windels, David; Vazquez, Franck; Blevins, Todd; Farinelli, Laurent; Pooggin, Mikhail M

    2012-09-01

    In plants, RNA silencing-based antiviral defense is mediated by Dicer-like (DCL) proteins producing short interfering (si)RNAs. In Arabidopsis infected with the bipartite circular DNA geminivirus Cabbage leaf curl virus (CaLCuV), four distinct DCLs produce 21, 22 and 24 nt viral siRNAs. Using deep sequencing and blot hybridization, we found that viral siRNAs of each size-class densely cover the entire viral genome sequences in both polarities, but highly abundant siRNAs correspond primarily to the leftward and rightward transcription units. Double-stranded RNA precursors of viral siRNAs can potentially be generated by host RDR-dependent RNA polymerase (RDR). However, genetic evidence revealed that CaLCuV siRNA biogenesis does not require RDR1, RDR2, or RDR6. By contrast, CaLCuV derivatives engineered to target 30 nt sequences of a GFP transgene by primary viral siRNAs trigger RDR6-dependent production of secondary siRNAs. Viral siRNAs targeting upstream of the GFP stop codon induce secondary siRNAs almost exclusively from sequences downstream of the target site. Conversely, viral siRNAs targeting the GFP 3'-untranslated region (UTR) induce secondary siRNAs mostly upstream of the target site. RDR6-dependent siRNA production is not necessary for robust GFP silencing, except when viral siRNAs targeted GFP 5'-UTR. Furthermore, viral siRNAs targeting the transgene enhancer region cause GFP silencing without secondary siRNA production. We conclude that the majority of viral siRNAs accumulating during geminiviral infection are RDR1/2/6-independent primary siRNAs. Double-stranded RNA precursors of these siRNAs are likely generated by bidirectional readthrough transcription of circular viral DNA by RNA polymerase II. Unlike transgenic mRNA, geminiviral mRNAs appear to be poor templates for RDR-dependent production of secondary siRNAs.

  17. The genome of African yam (Dioscorea cayenensis-rotundata complex) hosts endogenous sequences from four distinct Badnavirus species.

    Science.gov (United States)

    Umber, Marie; Filloux, Denis; Muller, Emmanuelle; Laboureau, Nathalie; Galzi, Serge; Roumagnac, Philippe; Iskra-Caruana, Marie-Line; Pavis, Claudie; Teycheney, Pierre-Yves; Seal, Susan E

    2014-10-01

    Several endogenous viral elements (EVEs) have been identified in plant genomes, including endogenous pararetroviruses (EPRVs). Here, we report the first characterization of EPRV sequences in the genome of African yam of the Dioscorea cayenensis-rotundata complex. We propose that these sequences should be termed 'endogenous Dioscorea bacilliform viruses' (eDBVs). Molecular characterization of eDBVs shows that they constitute sequences originating from various parts of badnavirus genomes, resulting in a mosaic structure that is typical of most EPRVs characterized to date. Using complementary molecular approaches, we show that eDBVs belong to at least four distinct Badnavirus species, indicating multiple, independent, endogenization events. Phylogenetic analyses of eDBVs support and enrich the current taxonomy of yam badnaviruses and lead to the characterization of a new Badnavirus species in yam. The impact of eDBVs on diagnosis, yam germplasm conservation and movement, and breeding is discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  18. [Ontogenetic Mechanisms of Explosive Morphological Divergence in the Lake Tana (Ethiopia) Species Flock of Large African Barbs (Labeobarbus; Cyprinidae; Teleostei)].

    Science.gov (United States)

    Shkila, F N; Lazebny, O E; Kapitanova, D V; Abdissa, Belay; Borisov, V B; Smirnov, S V

    2015-01-01

    Species flock of Lake Tana (Ethiopia) large African barbs (Labeobarbus; Cyprinidae; Teleostei) was studied as a model system for investigating ontogenetic mechanisms of the explosive morphological divergence often accompanying sympatric speciation in bony fishes. Comparative morphological analysis carried out with the use ofgeometric morphometric techniques revealed quantitative differences in the head shapes of species under study. Comparative analysis of skull development revealed significant interspecies differences in the temporal characteristics of craniogenesis in these species. These two lines of evidence suggest that heterochronies in craniogenesis underlie divergence in the head shapes of adult Tana barbs. This prediction was verified via experimental changes of temporal characteristics of craniogenesis in L. intermedius, a putative ancestor for the Lake Tana species flock. For this aim, timing and rate of skull development were changed by artificial manipulation of thyroid hormone levels. In sum, it was shown that it is heterochronies that underlie an explosive morphological divergence of the Lake Tana barbs species flock. Our findings together with those reported in the literature suggest variability in the activity of the hypothalamic-pituitary-thyroid axis to contribute to these heterochronies.

  19. Species discrimination of African savannah trees at leaf level using hyperspectral remote sensing

    CSIR Research Space (South Africa)

    Majeke, B

    2009-03-01

    Full Text Available . This study was carried out to assess the utility of hyperspectral remote sensing in discriminating the dominant species in the southern part of the park. The spectral reflectances of seven common tree species (Combretum apiculatum, Combretum hereroense...

  20. Relative lack of regeneration of shade-intolerant canopy species in some South African forests

    CSIR Research Space (South Africa)

    Midgley, JJ

    1995-01-01

    Full Text Available tent to have higher concentrations of leaf nitrogen, suggesting that they are shade-intolerant species. Similarly the canopy species which are recruiting adequately have low level of leaf nitrogen....

  1. Rapid assessment of the invasive status of eucalyptus species in two South African provinces

    CSIR Research Space (South Africa)

    Forsyth, GG

    2004-01-01

    Full Text Available Gum trees, or eucalypts (Eucalyptus species), have been targeted for invasive alien plant clearing programmes in many parts of South Africa. This has caused some dissatisfaction where the species concerned also have useful characteristics...

  2. Laboratory Investigations of African Pouched Rats (Cricetomys gambianus as a Potential Reservoir Host Species for Monkeypox Virus.

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    Christina L Hutson

    Full Text Available Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s. In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats and this rodent species' competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4 or West African (W-MPXV: n = 4; an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV between 3 and 27 days post infection (p.i. (up to 1X108 pfu/ml, with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  3. Antimicrobial activity of two South African honeys produced from indigenous Leucospermum cordifolium and Erica species on selected micro-organisms

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    Grobler Sias R

    2008-07-01

    Full Text Available Abstract Background Honey has been shown to have wound healing properties which can be ascribed to its antimicrobial activity. The antimicrobial activity can be effective against a broad spectrum of bacterial species especially those of medical importance. It has also been shown that there is considerable variation in the antimicrobial potency of different types of honey, which is impossible to predict. With this in mind we tested the antimicrobial activity of honeys produced from plants grown in South Africa for their antibacterial properties on selected standard strains of oral micro-organisms. Methods The honeys used were produced from the blossoms of Eucalyptus cladocalyx (Bluegum trees, an indigenous South African plant Leucospermum cordifolium (Pincushion, a mixture of wild heather shrubs, mainly Erica species (Fynbos and a Leptospermum scoparium (Manuka honey. Only pure honey which had not been heated was used. The honeys were tested for their antimicrobial properties with a broth dilution method. Results Although the honeys produced some inhibitory effect on the growth of the micro-organisms, no exceptionally high activity occurred in the South African honeys. The carbohydrate concentration plays a key role in the antimicrobial activity of the honeys above 25%. However, these honeys do contain other antimicrobial properties that are effective against certain bacterial species at concentrations well below the hypertonic sugar concentration. The yeast C. albicans was more resistant to the honeys than the bacteria. The species S. anginosus and S. oralis were more sensitive to the honeys than the other test bacteria. Conclusion The honeys produced from indigenous wild flowers from South Africa had no exceptionally high activity that could afford medical grade status.

  4. The taxonomic status of two West African Leptopelis species: L. macrotis Schiøtz, 1967 and L. spiritusnoctis Rödel, 2007 (Amphibia: Anura: Arthroleptidae

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    Mark-Oliver Roedel

    2014-03-01

    Full Text Available We herein examine the taxonomic status of two West African forest-dwelling Leptopelis species. The small L. spiritusnoctis, described from the Upper Guinean forests of West Africa, was recently synonymized with L. aubryi, described from Gabon. The large L. macrotis, known from Ghana to Sierra Leone, was downgraded to a subspecies of L. millsoni, ranging from the Niger Delta to eastern Democratic Republic of Congo. These taxonomic decisions are in contrast to the general biogeographic pattern of African forest anurans and we consequently tested if the morphologically similar taxon pairs are indeed conspecifics by applying acoustic and molecular techniques. Both techniques confirmed that populations from West Africa differ significantly from their Central African morphological equivalents. Consequently, we herein resurrect L. spiritusnoctis as a valid species. The acoustic data indicate that L. aubryi may comprise a complex of cryptic species. We further advocate using the name L. macrotis for West African and L. millsoni for Central African populations of these larger arboreal frogs. However, we had neither genetic nor acoustic data from the type locality of L. millsoni available and could not clarify if these frogs belong to the more western or eastern taxon or even represent a Nigerian endemic. Thus, it is possible that West African populations need to be termed L. millsoni in the future. For populations east of the Cross River, Nigeria, the name L. guineensis would be available.

  5. Field Trial and Molecular Characterization of RNAi-Transgenic Tomato Plants That Exhibit Resistance to Tomato Yellow Leaf Curl Geminivirus.

    Science.gov (United States)

    Fuentes, Alejandro; Carlos, Natacha; Ruiz, Yoslaine; Callard, Danay; Sánchez, Yadira; Ochagavía, María Elena; Seguin, Jonathan; Malpica-López, Nachelli; Hohn, Thomas; Lecca, Maria Rita; Pérez, Rosabel; Doreste, Vivian; Rehrauer, Hubert; Farinelli, Laurent; Pujol, Merardo; Pooggin, Mikhail M

    2016-03-01

    RNA interference (RNAi) is a widely used approach to generate virus-resistant transgenic crops. However, issues of agricultural importance like the long-term durability of RNAi-mediated resistance under field conditions and the potential side effects provoked in the plant by the stable RNAi expression remain poorly investigated. Here, we performed field trials and molecular characterization studies of two homozygous transgenic tomato lines, with different selection markers, expressing an intron-hairpin RNA cognate to the Tomato yellow leaf curl virus (TYLCV) C1 gene. The tested F6 and F4 progenies of the respective kanamycin- and basta-resistant plants exhibited unchanged field resistance to TYLCV and stably expressed the transgene-derived short interfering RNA (siRNAs) to represent 6 to 8% of the total plant small RNAs. This value outnumbered the average percentage of viral siRNAs in the nontransformed plants exposed to TYLCV-infested whiteflies. As a result of the RNAi transgene expression, a common set of up- and downregulated genes was revealed in the transcriptome profile of the plants selected from either of the two transgenic events. A previously unidentified geminivirus causing no symptoms of viral disease was detected in some of the transgenic plants. The novel virus acquired V1 and V2 genes from TYLCV and C1, C2, C3, and C4 genes from a distantly related geminivirus and, thereby, it could evade the repressive sequence-specific action of transgene-derived siRNAs. Our findings shed light on the mechanisms of siRNA-directed antiviral silencing in transgenic plants and highlight the applicability limitations of this technology as it may alter the transcriptional pattern of nontarget genes.

  6. [Chromosome arrangements and cytogenetic differentiation of two species of African mice of the genus Mus (Rodentia, Muridae)].

    Science.gov (United States)

    Aniskin, V M; Lavrenchenko, L A; Varshavskiĭ, A A; Milishnikov, A N

    1998-01-01

    Karyotypes of two African mouse species, Mus mahomet, 2n = 36, NFa = 34 (34A + XA + YA) and Mus sp. A, 2n = 34, NFa = 32 (32A + XA + YA), from five localities of the Bale Mountains National Park, Ethiopia, were analyzed. In both species all autosomes contained C-positive pericentromeric blocks. In M. mahomet, heterochromatin blocks of different chromosomes varied in size. In addition, the X chromosomes of both species contained a pericentromeric block and showed more intensive staining throughout the chromosome. The Y chromosome was two times larger in Mus sp. A than in M. mahomet and C-positive in both species. Comparative analysis of G-banding patterns revealed a similarity with respect to nine autosomes and the X chromosome. Autosome 1 of Mus sp. A was demonstrated to result from centromere-telomere fusion of two M. mahomet acrocentrics. The other five autosomes represent different linkage groups determining a specificity of the karyotypes. The karyotypes of M. mahomet and Mus sp. A were also compared with that of M. musculus. The evolution of M. mahomet and Mus sp. A karyotypes was shown to have involved structural rearrangements in 10 and 12 autosomes, respectively. The high karyological divergence confirmed molecular phylogenetic data. The cytogenetic differences T of M. musculus C from M. mahomet and Mus sp. A are high enough to different genera.

  7. Odd man out : why are there fewer plant species in African rain forests ?

    OpenAIRE

    Couvreur, Thomas

    2015-01-01

    Although tropical rain forests represent the most species-rich terrestrial ecosystem on the planet, the three main rain forest regions (Neotropics, South-East Asia and continental Africa) are not equally diverse. Africa has been labeled the "odd man out" because of its perceived lower species diversity when compared to the Neotropics or South-East Asia. Understanding why, within a biome, certain regions have higher or lower species diversity provides important insights into the evolution of b...

  8. The African buffalo: A villain for inter-species spread of infectious diseases in southern Africa

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    Anita L. Michel

    2012-06-01

    Full Text Available The African buffalo (Syncerus caffer is a large wild bovid which until recently ranged across all but the driest parts of sub-Saharan Africa, and their local range being limited to about 20 km from surface water. They are of high ecological value due to their important role as bulk feeders in the grazing hierarchy. They also have high economic value, because they are one of the sought after ‘Big Five’ in the eco-tourism industry. In Africa, buffaloes have been recognised for some time as an important role player in the maintenance and transmission of a variety of economically important livestock diseases at the wildlife and/or livestock interface. These include African strains of foot-and-mouth disease (FMD, Corridor disease (theileriosis, bovine tuberculosis and bovine brucellosis. For a number of other diseases of veterinary importance, African buffaloes may also serve as amplifier or incidental host, whereby infection with the causative pathogens may cause severe clinical signs such as death or abortion as in the case of anthrax and Rift Valley fever, or remain mild or subclinical for example heartwater. The long term health implications of most of those infections on the buffalo at a population level is usually limited, and they do not pose a threat on the population’s survival. Because of their ability to harbour and transmit important diseases to livestock, their sustainable future in ecotourism, trade and transfrontier conservation projects become complex and costly and reliable diagnostic tools are required to monitor these infections in buffalo populations.

  9. Solar drying and organoleptic characteristics of two tropical African fish species using improved low-cost solar driers.

    Science.gov (United States)

    Mustapha, Moshood K; Ajibola, Taiye B; Salako, Abdulbashir F; Ademola, Sunmola K

    2014-05-01

    This study was done to evaluate the drying performance, efficiency, and effectiveness of five different types of improved low-cost solar driers in terms of moisture loss from two tropical African fish species Clarias gariepinus (African sharp tooth catfish) and Oreochromis niloticus (Nile tilapia) and testing the organoleptic characteristics of the dried samples. The driers used were made from plastic, aluminum, glass, glass with black igneous stone, and mosquito net, with traditional direct open-sun drying as a control. A significant (P < 0.05) decrease in weight resulting from moisture loss in the two fish species was observed in all the driers, with the highest reduction occurring in the glass drier containing black stone. The rate of weight loss was faster in the first 4 days of drying with black stone-inserted glass drier showing the fastest drying rate with a constant weight in C. gariepinus attained on the 11th day and in O. niloticus on the eighth day. The slowest drier was plastic where a constant weight of the species were recorded on and 13th day and 11th day, respectively. Volunteers were used to assess the organoleptic characteristics of the dried samples and they showed lowest acceptability for the open-sun drying, while samples from the glass drier containing black stone had the highest acceptability in terms of the taste, flavor, appearance, texture, odor, palatability, and shelf-life. The low-cost solar driers were effective found in removing water from the fish resulting in significant loss of weight and moisture. The highest drying time, efficient performance, drying effectiveness, and high acceptability of the organoleptic parameters of the dried products from the black stone-inserted glass drier were due to the ability of the glass and the black stone to retain, transmit, and radiate heat to the fish sample all the time (day and night). These low-cost driers are simple to construct, materials for its construction readily available, easy to

  10. Incidence of begomoviruses and climatic characterisation of Bemisia tabaci-geminivirus complex in soybean and bean in Argentina Incidencia de begomovirus y caracterización climática del complejo Bemisia tabaci-geminivirus en soja y poroto en Argentina

    Directory of Open Access Journals (Sweden)

    V. Alemandri

    2012-06-01

    Full Text Available Since the 1990s geminiviruses have emerged as devastating pathogens in tropical and subtropical regions as well as in temperate regions. Recent studies accomplished molecular hybridization-based detection of three begomoviruses infecting soybean and bean crops in Argentina, Bean golden mosaic virus (BGMV, Soybean blistering mosaic virus (SbBMV and Tomato yellow spot virus (ToYSV. The aims of the present study were to determine incidence and prevalence of the three known geminiviruses in soybean and bean crops in Argentina following the same procedure and to characterize the sites where Bemisia tabaci-geminivirus complex was found based on climate data. The highest incidence values were observed in Salta province. BGMV exhibited the highest prevalence and incidence values in the bean crop, followed by SbBMV. In the soybean crop, SbBMV showed the highest prevalence and incidence values, followed by ToYSV. One hundred and three soybean and bean plots distributed in Argentina, where the Bemisia tabaci-geminivirus complex was detected, were characterized employing a Geographic Information System (GIS. The complex was found in warm and low rainfall areas; these climatic characteristics are consistent with those identified in a previously described model. A map with the probability of occurrence of B. tabaci-geminivirus, based on the climatic characteristics, was obtained.Desde la década de 1990, los geminivirus han emergido como patógenos devastadores en regiones tropicales, subtropicales y templadas. En estudios recientes, se ha desarrollado un método de detección de tres begomovirus infectando cultivos de soja y poroto en la Argentina, Bean golden mosaic virus (BGMV, Soybean blistering mosaic virus (SbBMV y Tomato yellow spot virus (ToYSV. El objetivo del presente estudio fue determinar la incidencia y prevalencia de estos tres geminivirus y caracterizar los sitios donde se encontró el complejo Bemisia tabaci-geminivirus basándose en datos

  11. On the West-African species of the subgenus Eupalaemon Ortm

    NARCIS (Netherlands)

    Man, de J.G.

    1911-01-01

    In addition to my description of Palaemon (Eupalaemon) Lenzii de Man (see p. 225 of this volume) I give here a key to the species of the subgenus Eupalaemon Ortm. as yet known to occur in the rivers of West-Africa. Six species are at present known from there, viz.: 1. Pal. (Eupalaemon) macrobrachion

  12. Insights into the functional characteristics of geminivirus rolling-circle replication initiator protein and its interaction with host factors affecting viral DNA replication.

    Science.gov (United States)

    Rizvi, Irum; Choudhury, Nirupam Roy; Tuteja, Narendra

    2015-02-01

    Geminiviruses are DNA viruses that infect several economically important crops, resulting in a reduction in their overall yield. These plant viruses have circular, single-stranded DNA genomes that replicate mainly by a rolling-circle mechanism. Geminivirus infection results in crosstalk between viral and cellular factors to complete the viral life cycle or counteract the infection as part of defense mechanisms of host plants. The geminiviral replication initiator protein Rep is the only essential viral factor required for replication. It is multifunctional and is known to interact with a number of host factors to modulate the cellular environment or to function as a part of the replication machinery. This review provides a holistic view of the research related to the viral Rep protein and various host factors involved in geminiviral DNA replication. Studies on the promiscuous nature of geminiviral satellite DNAs are also reviewed.

  13. Helminth parasitism in two closely related South African rodents: abundance, prevalence, species richness and impinging factors.

    Science.gov (United States)

    Spickett, Andrea; Junker, Kerstin; Krasnov, Boris R; Haukisalmi, Voitto; Matthee, Sonja

    2017-04-01

    We investigated patterns of helminth infection in two closely related rodents (social Rhabdomys pumilio occurring mainly in xeric habitats and solitary R. dilectus occurring mainly in mesic habitats) at 20 localities in different biomes of South Africa and asked if between-species differences were mainly caused by difference in sociality or difference in environmental conditions of their respective habitats. Helminths recovered from the gastrointestinal tract totalled 11 nematode and 5 cestode species from R. pumilio and 19 nematode and 7 cestode species from R. dilectus. In both hosts, mean abundance and prevalence of nematodes were higher compared to cestodes. Cestode infection as well as nematode abundance, species richness or prevalence did not differ between the two rodents. However, incidence of nematode infection was significantly higher in R. dilectus than in R. pumilio. Moreover, nematode numbers and species richness in infracommunities of R. pumilio inhabiting the relatively more xeric Karoo biome were significantly lower than in those inhabiting the relatively less xeric Fynbos biome. Although we could not unequivocally distinguish between effects of host sociality and environmental factors on the number of individuals and species of helminths in the two hosts, differences in the incidence of nematode infection between R. pumilio and R. dilectus as well as differences in the number of nematode individuals and species between R. pumilio from the Fynbos and the Karoo suggested the effect of environmental conditions on helminth infection to be more important than that of sociality.

  14. Otoliths of Five Extant Species of the Annual Killifish Nothobranchius from the East African Savannah

    Science.gov (United States)

    Reichenbacher, Bettina; Reichard, Martin

    2014-01-01

    This study presents, for the first time, a comprehensive dataset that documents the range of inter- and intraspecific otolith variation in aplocheiloid killifish, based on a total of 86 individuals representing five extant species of Nothobranchius PETERS, 1868, from East Africa: the sympatric pairs N. rubripinnis SEEGERS, 1986 and N. ruudwildekampi COSTA, 2009 (Eastern Tanzania), and N. orthonotus (PETERS, 1844) and N. furzeri JUBB, 1971 (Southern Mozambique), and two isolated populations of N. korthausae MEINKEN, 1973 (Eastern Tanzania). Otolith characters were analysed based on SEM images, and otolith morphometry was conducted using uni- and multivariate statistics. Two ancient clades of probably Early to Middle Miocene age in eastern Tanzania and southern Mozambique can be recognized based on otolith morphologies, which is consistent with previous work based on molecular data. The distinctive sulcus morphologies in the otoliths of sympatric species may be linked to species-specific hearing capabilities, perhaps constituting a case of character displacement in an area of secondary sympatry. The otoliths of the studied species of Nothobranchius are diagnostic at the species level, even in the case of closely related species diagnosable otherwise only by minor differences in coloration. The two populations of N. korthausae also displayed some differences in their otolith characters. The new data may facilitate future recognition of fossil species of Nothobranchius. As no fossil remains of extant aplocheiloid killifishes have yet been described, the discovery of fossil otoliths of Nothobranchius would significantly advance understanding of the evolutionary history of this interesting group of fishes. PMID:25383789

  15. The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes.

    Science.gov (United States)

    Ketseoglou, Irene; Bouwer, Gustav

    2012-10-04

    Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays. There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus PCC 7120#11 against the important malaria vectors An. gambiae and An. arabiensis was 12.3 × 10⁵ cells/ml and 8.10 × 105 cells/ml, respectively. PCC 7120#11 was not effective against An. funestus, with less than 50% mortality obtained at concentrations as high as 3.20 × 10⁷ cells/ml. PCC 7120#11 exhibited good larvicidal activity against larvae of the An. gambiae complex, but relatively weak larvicidal activity against An. funestus. The study has highlighted the importance of evaluating a novel mosquitocidal agent against a range of malaria vectors so as to obtain a clear understanding of the agent's spectrum of activity and potential as a vector control agent.

  16. Impact of temperature on performance in two species of South African dwarf chameleon, Bradypodion pumilum and B. occidentale.

    Science.gov (United States)

    Segall, Marion; Tolley, Krystal A; Vanhooydonck, Bieke; Measey, G John; Herrel, Anthony

    2013-10-15

    Temperature is an extrinsic factor that influences reptile behavior because of its impact on reptile physiology. Understanding the impact of temperature on performance traits is important as it may affect the ecology and fitness of ectothermic animals such as reptiles. Here, we examined the temperature dependence of performance in two species of South African dwarf chameleon (Bradypodion): one adapted to a semi-arid environment and one to a mesic environment. Ecologically relevant performance traits were tested at different temperatures to evaluate their thermal dependence, and temperature-performance breadths for 80% and 90% of each performance trait were calculated. Our results show distinct differences in the thermal dependence of speed- versus force-related performance traits. Moreover, our results show that the semi-arid species is better adapted to higher temperatures and as such has a better chance of coping with the predicted increases in environmental temperature. The mesic area-adapted species seems to be more sensitive to an increase in temperature and could therefore potentially be threatened by the predicted future climate change. However, further studies investigating the potential for acclimation in chameleons are needed to better understand how animals may respond to future climate change.

  17. Evolution of endogenous retroviruses in the Suidae: evidence for different viral subpopulations in African and Eurasian host species

    Directory of Open Access Journals (Sweden)

    Charleston Michael

    2011-05-01

    Full Text Available Abstract Background Porcine endogenous retroviruses (PERVs represent remnants of an exogenous form that have become integrated in the domestic pig (Sus scrofa genome. Although they are usually inactive, the capacity of γ1 ERVs to infect human cells in vitro has raised concerns about xenotransplantation because the viruses could cross the species barrier to humans. Here we have analyzed the evolution of γ1 ERVs in ten species of Suidae (suids, pigs and hogs from Eurasia and Africa using DNA sequences for their coding domains (gag, pro/pol and env genes. For comparison with γ1 PERVs, we have also analysed γ2 ERVs which in domestic pigs are known to be inactive and do not pose a risk to xenotransplantation. Results Phylogenetic analysis using Bayesian inference showed that γ1 and γ2 ERVs have distinctive evolutionary histories. Firstly, two different viral lineages of γ1 ERVs were found and a coevolutionary analysis demonstrated that they correspond broadly to their host phylogeny, one of Eurasian and another of African species, and show no evidence of horizontal transmission. γ2 ERVs, however, show a bush-like evolution, suggesting a rapid viral radiation from a single common ancestor with no correspondence between host and viral evolutionary trees. Furthermore, though γ1 ERV env genes do not possess frequent stop codons, γ2 env genes do. To understand whether γ1 suid ERVs may be still replicating, we have also evaluated their likely mechanism of proliferation by statistically testing internal to terminal branches using nonsynonymous versus synonymous substitution ratios. Our results suggest that γ1 ERVs are increasing in copy number by reinfection, which requires the translocation of the virus from one cell to another. Conclusions Evidence of at least two viral subpopulations was observed in γ1 ERVs from Eurasian and African host species. These results should be taken into account in xenotransplantation since γ1 ERVs appear to be

  18. A description of two new species of coccidia (Apicomplexa: Eimeriidae) from African reptiles with nomenclatural corrections for two Caryospora and one Eimeria species from snakes.

    Science.gov (United States)

    Daszak, P; Ball, S J

    2001-01-01

    Two new species of coccidian parasites are described from African reptiles. Oocysts of Eimeria foulshami sp. n. from the plated lizard Gerrhosaurus major bottegoi Del Prato of Sudan are ellipsoidal, 24.1 x 14.9 (23-26.5 x 14-17.8) microm with a bilayered, colourless oocyst wall and lack polar granules. The ellipsoidal sporocysts average 8.6 x 4.6 (7-10.6 x 4.4-7) microm and possess a prominent, globular, sporocyst residuum. Oocysts of Caryospora regentensis sp. n. from the Eastern green mamba Dendroaspis augusticeps Smith, 1849 [corrected] of Kenya are spherical to subspherical, 16.8 x 16.4 (16-17.6 x 15-17.2) microm with a bilayered oocyst wall and a single polar granule. The ellipsoidal sporocysts average 13.0 x 10.3 (10.2-14 x 9.2-11) microm and possess a Stieda and substieda body and a prominent globular sporocyst residuum. Oocysts of Caryospora legeri Hoare, 1933 are reported from a hissing sand snake, Psammophis sibilans sibilans L. from Nigeria, representing a new geographical record. The oocysts are slightly larger than the type, but otherwise identical. Caryospora psammophi Bray, 1960 and C. hermae Bray, 1960 from Psammophis sibilans phillipsi, oocysts of which are morphologically similar to and overlap in dimensions with C. legeri Hoare, 1933, are synonymised with the latter species. Eimeria samiae Iskander et Tadros, 1979 is emended to E. samyadeli to reflect the gender of the person the species was named after and because E. sani is preoccupied. In addition to these findings, Eimeria bohemi Modrý, Slapeta et Koudela, 2000 and oocysts of an unidentified spherical Eimieria sp. are reported from Chamaeleo dilepis dilepis Leach from Cameroon.

  19. Shifts in climate foster exceptional opportunities for species radiation: the case of South african geraniums.

    Directory of Open Access Journals (Sweden)

    Hugo I Martínez-Cabrera

    Full Text Available Climate change is often assumed to be a major driver of biodiversity loss. However, it can also set the stage for novel diversification in lineages with the evolutionary ability to colonize new environments. Here we tested if the extraordinary evolutionary success of the genus Pelargonium was related to the ability of its species to capitalize on the climate niche variation produced by the historical changes in southern Africa. We evaluated the relationship between rates of climate niche evolution and diversification rates in the main Pelargonium lineages and disentangled the roles of deep and recent historical events in the modification of species niches. Pelargonium clades exhibiting higher ecological differentiation along summer precipitation (SPP gradients also experienced higher diversification rates. Faster rates of niche differentiation in spatially structured variables, along with lower levels of niche overlap among closely related species, suggest recent modification in species niches (e.g. dispersal or range shift and niche lability. We suggest that highly structured SPP gradients established during the aridification process within southern Africa, in concert with niche lability and low niche overlap, contributed to species divergence. These factors are likely to be responsible for the extensive diversification of other lineages in this diversity hot spot.

  20. Shifts in climate foster exceptional opportunities for species radiation: the case of South african geraniums.

    Science.gov (United States)

    Martínez-Cabrera, Hugo I; Peres-Neto, Pedro R

    2013-01-01

    Climate change is often assumed to be a major driver of biodiversity loss. However, it can also set the stage for novel diversification in lineages with the evolutionary ability to colonize new environments. Here we tested if the extraordinary evolutionary success of the genus Pelargonium was related to the ability of its species to capitalize on the climate niche variation produced by the historical changes in southern Africa. We evaluated the relationship between rates of climate niche evolution and diversification rates in the main Pelargonium lineages and disentangled the roles of deep and recent historical events in the modification of species niches. Pelargonium clades exhibiting higher ecological differentiation along summer precipitation (SPP) gradients also experienced higher diversification rates. Faster rates of niche differentiation in spatially structured variables, along with lower levels of niche overlap among closely related species, suggest recent modification in species niches (e.g. dispersal or range shift) and niche lability. We suggest that highly structured SPP gradients established during the aridification process within southern Africa, in concert with niche lability and low niche overlap, contributed to species divergence. These factors are likely to be responsible for the extensive diversification of other lineages in this diversity hot spot.

  1. NASA and USGS invest in invasive species modeling to evaluate habitat for Africanized Honey Bees

    Science.gov (United States)

    2009-01-01

    Invasive non-native species, such as plants, animals, and pathogens, have long been an interest to the U.S. Geological Survey (USGS) and NASA. Invasive species cause harm to our economy (around $120 B/year), the environment (e.g., replacing native biodiversity, forest pathogens negatively affecting carbon storage), and human health (e.g., plague, West Nile virus). Five years ago, the USGS and NASA formed a partnership to improve ecological forecasting capabilities for the early detection and containment of the highest priority invasive species. Scientists from NASA Goddard Space Flight Center (GSFC) and the Fort Collins Science Center developed a longterm strategy to integrate remote sensing capabilities, high-performance computing capabilities and new spatial modeling techniques to advance the science of ecological invasions [Schnase et al., 2002].

  2. New African species of Echinobothrium (Cestoda: Diphyllidea) and implications for the identities of their skate hosts.

    Science.gov (United States)

    Caira, J N; Rodriguez, N; Pickering, M

    2013-10-01

    Two new species of diphyllidean cestodes of the genus Echinobothrium, each hosted by a different skate species in the Raja miraletus complex, are described. Echinobothrium mercedesae n. sp. is described from R. cf. miraletus 2 off Senegal. Echinobothrium yiae n. sp. is described from R. cf. miraletus 1 off South Africa. Both species are small worms that differ from their 29 described congeners in the combination of number of cephalic peduncle spines per column, hook formula, number and arrangement of testes, and arrangement of vitelline follicles. They are easily distinguished from one another in that whereas the vitelline follicles of E. yiae n. sp. are circumcortical, they are lateral in E. mercedesae n. sp., and also in number of cephalic peduncle spines per column (14-17 vs. 10-12). Echinobothrium yiae n. sp. is also unusual in that the cephalic peduncle spines stop short of the anterior margin of the peduncle. In addition, although the paucity of available material precluded their formal description, evidence of 2 additional new species parasitizing R. miraletus also from Senegal is presented. In combination these worms provide support for the interpretation that what is currently recognized as Raja miraletus actually consists of a complex of geographically restricted species, rather than a polymorphic species of multiple parapatric or allopatrically distributed populations. This interpretation is not only supported by previously published molecular data, but also by newly collected morphological data involving differences in the color patterns of disc ocelli among host specimens of the 3 forms available as a result of digital efforts to ensure the accuracy of host identifications, which are also presented here.

  3. Antioxidant, antiinflammatory activities and HPLC analysis of South African Salvia species

    CSIR Research Space (South Africa)

    Kamatou, GGP

    2010-03-01

    Full Text Available The antioxidant and antiinflammatory activities of the methanol:chloroform (1:1) extracts of 16 Salvia species indigenous to South Africa were evaluated. Antioxidant activity was measured using the 2,20- azino-bis (3-ethylbenzothiazoline-6-sulfonic...

  4. The effects of barotrauma on five species of South African line ...

    African Journals Online (AJOL)

    We investigated the effects of barotrauma on five commercially important species: roman Chrysoblephus laticeps, silver kob Argyrosomus inodorus, hottentot Pachymetopon blochii, santer Cheimerius nufar and carpenter Argyrozona argyrozona. A classification of the external signs of barotrauma was developed and ...

  5. Landscape-scale variation in plant community composition of an African savanna from airborne species mapping.

    Science.gov (United States)

    Baldeck, C A; Colgan, M S; Féret, J B; Levick, S R; Martin, R E; Asner, G P

    2014-01-01

    Information on landscape-scale patterns in species distributions and community types is vital for ecological science and effective conservation assessment and planning. However, detailed maps of plant community structure at landscape scales seldom exist due to the inability of field-based inventories to map a sufficient number of individuals over large areas. The Carnegie Airborne Observatory (CAO) collected hyperspectral and lidar data over Kruger National Park, South Africa, and these data were used to remotely identify > 500 000 tree and shrub crowns over a 144-km2 landscape using stacked support vector machines. Maps of community compositional variation were produced by ordination and clustering, and the importance of hillslope-scale topo-edaphic variation in shaping community structure was evaluated with redundancy analysis. This remote species identification approach revealed spatially complex patterns in woody plant communities throughout the landscape that could not be directly observed using field-based methods alone. We estimated that topo-edaphic variables representing catenal sequences explained 21% of species compositional variation, while we also uncovered important community patterns that were unrelated to catenas, indicating a large role for other soil-related factors in shaping the savanna community. Our results demonstrate the ability of airborne species identification techniques to map biodiversity for the evaluation of ecological controls on community composition over large landscapes.

  6. Laboratory investigations of African Pouched Rats (Cricetomys gambianus) as a potential reservoir host species for Monkeypox Virus

    Science.gov (United States)

    Hutson, Christina L.; Nakazawa, Yoshinori J.; Self, Joshua; Olson, Victoria A.; Regnery, Russell L.; Braden, Zachary; Weiss, Sonja; Malekani, Jean; Jackson, Eddie; Tate, Mallory; Karem, Kevin L.; Rocke, Tonie E.; Osorio, Jorge E.; Damon, Inger K.; Carroll, Darin S.

    2015-01-01

    Monkeypox is a zoonotic disease endemic to central and western Africa, where it is a major public health concern. Although Monkeypox virus (MPXV) and monkeypox disease in humans have been well characterized, little is known about its natural history, or its maintenance in animal populations of sylvatic reservoir(s). In 2003, several species of rodents imported from Ghana were involved in a monkeypox outbreak in the United States with individuals of three African rodent genera (Cricetomys, Graphiurus, Funisciurus) shown to be infected with MPXV. Here, we examine the course of MPXV infection in Cricetomys gambianus (pouched Gambian rats) and this rodent species’ competence as a host for the virus. We obtained ten Gambian rats from an introduced colony in Grassy Key, Florida and infected eight of these via scarification with a challenge dose of 4X104 plaque forming units (pfu) from either of the two primary clades of MPXV: Congo Basin (C-MPXV: n = 4) or West African (W-MPXV: n = 4); an additional 2 animals served as PBS controls. Viral shedding and the effect of infection on activity and physiological aspects of the animals were measured. MPXV challenged animals had significantly higher core body temperatures, reduced activity and increased weight loss than PBS controls. Viable virus was found in samples taken from animals in both experimental groups (C-MPXV and W-MPXV) between 3 and 27 days post infection (p.i.) (up to 1X108pfu/ml), with viral DNA found until day 56 p.i. The results from this work show that Cricetomys gambianus (and by inference, probably the closely related species, Cricetomys emini) can be infected with MPXV and shed viable virus particles; thus suggesting that these animals may be involved in the maintenance of MPXV in wildlife mammalian populations. More research is needed to elucidate the epidemiology of MPXV and the role of Gambian rats and other species.

  7. Arabidopsis RNA Polymerase V Mediates Enhanced Compaction and Silencing of Geminivirus and Transposon Chromatin during Host Recovery from Infection.

    Science.gov (United States)

    Coursey, Tami; Regedanz, Elizabeth; Bisaro, David M

    2018-04-01

    Plants employ RNA-directed DNA methylation (RdDM) and dimethylation of histone 3 lysine 9 (H3K9me2) to silence geminiviruses and transposable elements (TEs). We previously showed that canonical RdDM (Pol IV-RdDM) involving RNA polymerases IV and V (Pol IV and Pol V) is required for Arabidopsis thaliana to recover from infection with Beet curly top virus lacking a suppressor protein that inhibits methylation (BCTV L2 - ). Recovery, which is characterized by reduced viral DNA levels and symptom remission, allows normal floral development. Here, we used formaldehyde-assisted isolation of regulatory elements (FAIRE) to confirm that >90% of BCTV L2 - chromatin is highly compacted during recovery, and a micrococcal nuclease-chromatin immunoprecipitation assay showed that this is largely due to increased nucleosome occupancy. Physical compaction correlated with augmented cytosine and H3K9 methylation and with reduced viral gene expression. We additionally demonstrated that these phenomena are dependent on Pol V and by extension the Pol IV-RdDM pathway. BCTV L2 - was also used to evaluate the impact of viral infection on host loci, including repressed retrotransposons Ta3 and Athila6A Remarkably, an unexpected Pol V-dependent hypersuppression of these TEs was observed, resulting in transcript levels even lower than those detected in uninfected plants. Hypersuppression is likely to be especially important for natural recovery from wild-type geminiviruses, as viral L2 and AL2 proteins cause ectopic TE expression. Thus, Pol IV-RdDM targets both viral and TE chromatin during recovery, simultaneously silencing the majority of viral genomes and maintaining host genome integrity by enforcing tighter control of TEs in future reproductive tissues. IMPORTANCE In plants, RdDM pathways use small RNAs to target cytosine and H3K9 methylation, thereby silencing DNA virus genomes and transposable elements (TEs). Further, Pol IV-RdDM involving Pol IV and Pol V is a key aspect of host

  8. Karyotype and Mapping of Repetitive DNAs in the African Butterfly Fish Pantodon buchholzi, the Sole Species of the Family Pantodontidae.

    Science.gov (United States)

    Ráb, Petr; Yano, Cassia F; Lavoué, Sébastien; Jegede, Oladele I; Bertollo, Luiz A C; Ezaz, Tariq; Majtánová, Zuzana; de Oliveira, Ezequiel A; Cioffi, Marcelo B

    2016-01-01

    The monophyletic order Osteoglossiformes represents one of the most ancestral groups of teleosts and has at least 1 representative in all continents of the southern hemisphere, with the exception of Antarctica. However, despite its phylogenetic and biogeographical importance, cytogenetic data in Osteoglossiformes are scarce. Here, karyotype and chromosomal characteristics of the lower Niger River population of the African butterfly fish Pantodon buchholzi, the sole species of the family Pantodontidae (Osteoglossiformes), were examined using conventional and molecular cytogenetic approaches. All specimens examined had 2n = 46 chromosomes, with a karyotype composed of 5 pairs of metacentric, 5 pairs of submetacentric, and 13 pairs of acrocentric chromosomes in both sexes. No morphologically differentiated sex chromosomes were identified. C-bands were located in the centromeric/pericentromeric region of all chromosomes and were associated with the single AgNOR site. FISH with ribosomal DNA probes revealed that both 5S and 18S rDNA were present in only 1 pair of chromosomes each, but did not colocalize. CMA3+ bands were observed near the telomeres in several chromosome pairs and also at the 18S rDNA sites. The mapping of di- and trinucleotide repeat motifs, Rex6 transposable element, and U2 snRNA showed a scattered distribution over most of the chromosomes, but for some microsatellites and the U2 snRNA also a preferential accumulation at telomeric regions. This study presents the first detailed cytogenetic analysis in the African butterfly fish by both conventional and molecular cytogenetic protocols. This is the first of a series of further cytogenetic and cytogenomic studies on osteoglossiforms, aiming to comprehensively examine the chromosomal evolution in this phylogenetically important fish order. © 2016 S. Karger AG, Basel.

  9. Discovery and Characterization of Distinct Simian Pegiviruses in Three Wild African Old World Monkey Species

    OpenAIRE

    Sibley, Samuel D.; Lauck, Michael; Bailey, Adam L.; Hyeroba, David; Tumukunde, Alex; Weny, Geoffrey; Chapman, Colin A.; O’Connor, David H.; Goldberg, Tony L.; Friedrich, Thomas C.

    2014-01-01

    Within the Flaviviridae, the recently designated genus Pegivirus has expanded greatly due to new discoveries in bats, horses, and rodents. Here we report the discovery and characterization of three simian pegiviruses (SPgV) that resemble human pegivirus (HPgV) and infect red colobus monkeys (Procolobus tephrosceles), red-tailed guenons (Cercopithecus ascanius) and an olive baboon (Papio anubis). We have designated these viruses SPgVkrc, SPgVkrtg and SPgVkbab, reflecting their host species' co...

  10. Species boundaries and taxonomy of the African river frogs (Amphibia: Pyxicephalidae: Amietia).

    Science.gov (United States)

    Channing, A; Dehling, J M; Lötters, S; Ernst, R

    2016-08-25

    A molecular phylogeny of the Afrotropical anuran genus Amietia based on 323 16S sequences indicates that there are 19 species, including four not yet described. No genetic material was available for the nominal A. inyangae. We consider them to represent full species, and define them based on 16S genetic distances, as well as differences in morphology, tadpoles and advertisement call where known. An analysis based on two mitochondrial and two nuclear genes (12S, 16S, 28S and tyrosinase exon 1), from 122 samples, confirmed the phylogenetic relationships suggested by the 16S tree. We recognise and (re-) describe the following species: Amietia angolensis (Bocage, 1866), A. chapini (Noble, 1924), A. delalandii (Duméril & Bibron, 1841), A. desaegeri (Laurent, 1972), A. fuscigula (Duméril & Bibron, 1841), A. hymenopus (Boulenger, 1920), A. inyangae (Poynton, 1966), A. johnstoni (Günther, 1893), A. moyerorum sp. nov., A. nutti (Boulenger, 1896), A. poyntoni Channing & Baptista, 2013, A. ruwenzorica (Laurent, 1972), A. tenuoplicata (Pickersgill, 2007), A. vandijki (Visser & Channing, 1997), A. vertebralis (Hewitt, 1927), and A. wittei (Angel, 1924). Three further candidate species of Larson et al. (2016) await formal naming. We provisionally regard A. amieti (Laurent, 1976) as a junior synonym of A. chapini (Noble, 1924). Amietia lubrica (Pickersgill, 2007) is shown to be a junior synonym of A. nutti, while A. quecketti (Boulenger, 1895) is shown to be a junior synonym of A. delalandii (Duméril & Bibron, 1841), and A. viridireticulata (Pickersgill, 2007) is placed as a junior synonym of A. tenuoplicata (Pickersgill, 2007). On the basis of similarity of 16S sequences, we assign A. sp. 1, A. sp. 3 and A. sp. 6 of Larson et al (2016) to the nomina A. chapini (Noble, 1924), A. desaegeri (Laurent, 1972), and A. nutti (Boulenger, 1896) respectively.

  11. The susceptibility of five African Anopheles species to Anabaena PCC 7120 expressing Bacillus thuringiensis subsp. israelensis mosquitocidal cry genes

    Directory of Open Access Journals (Sweden)

    Ketseoglou Irene

    2012-10-01

    Full Text Available Abstract Background Malaria, one of the leading causes of death in Africa, is transmitted by the bite of an infected female Anopheles mosquito. Problems associated with the development of resistance to chemical insecticides and concerns about the non-target effects and persistence of chemical insecticides have prompted the development of environmentally friendly mosquito control agents. The aim of this study was to evaluate the larvicidal activity of a genetically engineered cyanobacterium, Anabaena PCC 7120#11, against five African Anopheles species in laboratory bioassays. Findings There were significant differences in the susceptibility of the anopheline species to PCC 7120#11. The ranking of the larvicidal activity of PCC 7120#11 against species in the An. gambiae complex was: An. merus An. arabiensis An. gambiae An. quadriannulatus, where 50. The LC50 of PCC 7120#11 against the important malaria vectors An. gambiae and An. arabiensis was 12.3 × 105 cells/ml and 8.10 × 105 cells/ml, respectively. PCC 7120#11 was not effective against An. funestus, with less than 50% mortality obtained at concentrations as high as 3.20 × 107 cells/ml. Conclusions PCC 7120#11 exhibited good larvicidal activity against larvae of the An. gambiae complex, but relatively weak larvicidal activity against An. funestus. The study has highlighted the importance of evaluating a novel mosquitocidal agent against a range of malaria vectors so as to obtain a clear understanding of the agent’s spectrum of activity and potential as a vector control agent.

  12. Culicoides species abundance and potential over-wintering of African horse sickness virus in the Onderstepoort area, Gauteng, South Africa

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2014-11-01

    Full Text Available In South Africa, outbreaks of African horse sickness (AHS occur in summer; no cases are reported in winter, from July to September. The AHS virus (AHSV is transmitted almost exclusively by Culicoides midges (Diptera: Ceratopogonidae, of which Culicoides imicola is considered to be the most important vector. The over-wintering mechanism of AHSV is unknown. In this study, more than 500 000 Culicoides midges belonging to at least 26 species were collected in 88 light traps at weekly intervals between July 2010 and September 2011 near horses in the Onderstepoort area of South Africa. The dominant species was C. imicola. Despite relatively low temperatures and frost, at least 17 species, including C. imicola, were collected throughout winter (June–August. Although the mean number of midges per night fell from > 50 000 (March to < 100 (July and August, no midge-free periods were found. This study, using virus isolation on cell cultures and a reverse transcriptase polymerase chain reaction (RT-PCR assay, confirmed low infection prevalence in field midges and that the detection of virus correlated to high numbers. Although no virus was detected during this winter period, continuous adult activity indicated that transmission can potentially occur. The absence of AHSV in the midges during winter can be ascribed to the relatively low numbers collected coupled to low infection prevalence, low virus replication rates and low virus titres in the potentially infected midges. Cases of AHS in susceptible animals are likely to start as soon as Culicoides populations reach a critical level.

  13. Using Social Media to Measure the Contribution of Red List Species to the Nature-Based Tourism Potential of African Protected Areas.

    Science.gov (United States)

    Willemen, Louise; Cottam, Andrew J; Drakou, Evangelia G; Burgess, Neil D

    2015-01-01

    Cultural ecosystem services are defined by people's perception of the environment, which make them hard to quantify systematically. Methods to describe cultural benefits from ecosystems typically include resource-demanding survey techniques, which are not suitable to assess cultural ecosystem services for large areas. In this paper we explore a method to quantify cultural benefits through the enjoyment of natured-based tourism, by assessing the potential tourism attractiveness of species for each protected area in Africa using the IUCN's Red List of Threatened Species. We use the number of pictures of wildlife posted on a photo sharing website as a proxy for charisma, popularity, and ease of observation, as these factors combined are assumed to determine how attractive species are for the global wildlife tourist. Based on photo counts of 2473 African animals and plants, species that seem most attractive to nature-based tourism are the Lion, African Elephant and Leopard. Combining the photo counts with species range data, African protected areas with the highest potential to attract wildlife tourists based on attractive species occurrence were Samburu National Reserve in Kenya, Mukogodo Forest Reserve located just north of Mount Kenya, and Addo Elephant National Park in South-Africa. The proposed method requires only three data sources which are freely accessible and available online, which could make the proposed index tractable for large scale quantitative ecosystem service assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad understanding of those species that are popular globally; in many cases these are not the species of highest conservation concern.

  14. Using Social Media to Measure the Contribution of Red List Species to the Nature-Based Tourism Potential of African Protected Areas.

    Directory of Open Access Journals (Sweden)

    Louise Willemen

    Full Text Available Cultural ecosystem services are defined by people's perception of the environment, which make them hard to quantify systematically. Methods to describe cultural benefits from ecosystems typically include resource-demanding survey techniques, which are not suitable to assess cultural ecosystem services for large areas. In this paper we explore a method to quantify cultural benefits through the enjoyment of natured-based tourism, by assessing the potential tourism attractiveness of species for each protected area in Africa using the IUCN's Red List of Threatened Species. We use the number of pictures of wildlife posted on a photo sharing website as a proxy for charisma, popularity, and ease of observation, as these factors combined are assumed to determine how attractive species are for the global wildlife tourist. Based on photo counts of 2473 African animals and plants, species that seem most attractive to nature-based tourism are the Lion, African Elephant and Leopard. Combining the photo counts with species range data, African protected areas with the highest potential to attract wildlife tourists based on attractive species occurrence were Samburu National Reserve in Kenya, Mukogodo Forest Reserve located just north of Mount Kenya, and Addo Elephant National Park in South-Africa. The proposed method requires only three data sources which are freely accessible and available online, which could make the proposed index tractable for large scale quantitative ecosystem service assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad understanding of those species that are popular globally; in many cases these are not the species of highest conservation concern.

  15. Genospecies and virulence factors of Aeromonas species in different sources in a North African country

    Directory of Open Access Journals (Sweden)

    Khalifa Sifaw Ghenghesh

    2014-09-01

    Full Text Available Introduction: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few. Methods: In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28] in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR was used to detect genes encoding toxins from 52 of the isolates. Results: We identified 44 isolates (44% as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae; 27 isolates (27% as A. veronii; 23 isolates (23% as A. caviae; and 5 isolates (5.0% as other genospecies. The genes encoding aerolysin (aer, cytolytic enterotoxin (act, and A. hydrophila isolate SSU enterotoxin (ast were detected in 45 (87%, 4 (7.7%, and 9 (17% of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt was not detected. Conclusion: The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae, and genes coding for toxin production are common among them.

  16. Identification of a novel receptor-like protein kinase that interacts with a geminivirus nuclear shuttle protein

    International Nuclear Information System (INIS)

    Mariano, Andrea C.; Andrade, Maxuel O.; Santos, Anesia A.; Carolino, Sonia M.B.; Oliveira, Marli L.; Baracat-Pereira, Maria Cristina; Brommonshenkel, Sergio H.; Fontes, Elizabeth P.B.

    2004-01-01

    Despite extensive studies in plant virus-host interactions, the molecular mechanisms of geminivirus movement and interactions with host components remain largely unknown. A tomato kinase protein and its soybean homolog were found to interact specifically with the nuclear shuttle protein (NSP) of Tomato golden mosaic virus (TGMV) and Tomato crinkle leaf yellows virus (TCrLYV) through yeast two-hybrid screening and in vitro protein binding assays. These proteins, designated LeNIK (Lycopersicon esculentum NSP-Interacting Kinase) and GmNIK (Glycine max NIK), belong to the LRR-RLK (leucine rich-repeat receptor-like kinase) family that is involved in plant developmental processes and/or resistance response. As such, NIK is structurally organized into characteristic domains, including a serine/threonine kinase domain with a nucleotide binding site at the C-terminal region, an internal transmembrane segment and leucine-rich repeats (LRR) at the N-terminal portion. The potential significance of the NSP-NIK interaction is discussed

  17. Endangered West African Chimpanzees Pan troglodytes verus (Schwarz, 1934 (Primates: Hominidae in Senegal prefer Pterocarpus erinaceus, a threatened tree species, to build their nests: implications for their conservation

    Directory of Open Access Journals (Sweden)

    P.I. Ndiaye

    2013-12-01

    Full Text Available The West African Chimpanzee Pan troglodytes verus is Endangered (A4cd ver 3.1 in Senegal (Humle et al. 2008, mainly due to habitat fragmentation and destruction. We gathered qualitative and quantitative data on the tree species preferences of the West African Chimpanzee for nest building in order to gain insight into habitat dependence. Between March 1998 and Febrary 2000 we identified tree species in which a sample of 1790 chimpanzee nests had been built, and ranked species in preference order. We compared this sample to the relative abundance of tree species in the chimpanzee habitat to determine whether particular species were chosen for nesting. We observed that about a quarter (25.42% of nests were built in Pterocarpus erinaceus, which is considerably greater than would be expected from the abundance of this species in the habitat (6.35%, indicating a strong preference by chimpanzees. We examined the physical traits of the most-used tree species and concluded that height and wood hardness may be key choice features. P. erinaceus is threatened in Senegal due to extensive cutting, which may endanger chimpanzees living outside the boundaries of protected areas. In the current anthropogenic setting our results provide conservation managers with information on how to protect a key aspect of the chimpanzee natural environment.

  18. Romulea pilosa and R. quartzicola (Iridaceae: Crocoideae, two new species from the southern African winter rainfall region, with nomenclatural corrections

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2011-12-01

    Full Text Available Romulea pilosa J.C.Manning & Goldblatt and R. quartzicola J.C.Manning & Goldblatt are two narrow endemics from the southern African winter rainfall region. An early, fragmentary collection of R. pilosa from Riviersonderend lacked the diagnostic corm and was thus mistakenly associated with R. tetragona (sect. Ciliatae as var. flavandra M.P.de Vos because of the highly distinctive pilose, H-shaped leaf. The rediscovery of the taxon in the wild shows it to be a previously unrecognized member of sect. Aggregatae, distinguished by its unusual foliage and bright orange flowers. R. quartzicola was grown to flowering from seeds collected from quartz patches in southern Namaqualand and proved to be a new species of sect. Ciliatae, distinguished by its early flowering, short, subclavate leaves with reduced sclerenchyma strands, and bright yellow flowers with short bracts. R. neglecta M.P.de Vos, a rare endemic from the Kamiesberg in Northern Cape, is a later homonym for the Mediterranean R. neglecta Jord. & Fourr., and the earliest name for this plant is shown to be R. speciosa (Ker Gawl. Baker, typified by an illustration in Andrews’ The botanist’s repository. An epitype is designated to fix the application of the name. We have also examined the type illustration of R. pudica (Sol. ex Ker Gawl. Baker, hitherto treated as an uncertain species, and are confident that it represents the species currently known as R. amoena Schltr. ex Bég., and takes priority over it as being the earlier name. The type of R. reflexa Eckl., a new name for the later homonym I. reflexa Thunb. and the basionym of R. rosea var. reflexa (Eckl. Bég., has been mistakenly identified as an Ecklon collection but is in fact the collection that formed the basis of Thunberg’s I. reflexa. This collection is actually a form of R. flava Lam., and the name R. rosea var. reflexa is thus moved to the synonomy of that species. The variety currently known under this name should now be

  19. Assessment of the repellent effect of citronella and lemon eucalyptus oil against South African Culicoides species

    Directory of Open Access Journals (Sweden)

    Gert J. Venter

    2014-08-01

    Full Text Available The use of insect repellents to reduce the attack rate of Culicoides species (Diptera:Ceratopogonidae should form part of an integrated control programme to combat Africanhorse sickness and other diseases transmitted by these blood-feeding midges. In the presentstudy the repellent effects of a commercially available mosquito repellent, a combinationof citronella and lemon eucalyptus oils, on Culicoides midges was determined. The numberof midges collected with two 220 V Onderstepoort traps fitted with 8 W 23 cm white lighttubes and baited with peel-stick patches, each containing 40 mg of active ingredient, wascompared with that of two unbaited traps. Two trials were conducted and in each trial thefour traps were rotated in two replicates of a 4 x 4 randomised Latin square design. Althoughmore midges were collected in the baited traps, the mean number in the baited and unbaitedtraps was not significantly different. This mosquito repellent did not influence either thespecies composition or the physiological groups of Culicoides imicola Kieffer. The highermean numbers in the baited traps, although not statistically significant, may indicate that thismosquito repellent might even attract Culicoides midges under certain conditions.

  20. A hybrid phylogenetic-phylogenomic approach for species tree estimation in African Agama lizards with applications to biogeography, character evolution, and diversification.

    Science.gov (United States)

    Leaché, Adam D; Wagner, Philipp; Linkem, Charles W; Böhme, Wolfgang; Papenfuss, Theodore J; Chong, Rebecca A; Lavin, Brian R; Bauer, Aaron M; Nielsen, Stuart V; Greenbaum, Eli; Rödel, Mark-Oliver; Schmitz, Andreas; LeBreton, Matthew; Ineich, Ivan; Chirio, Laurent; Ofori-Boateng, Caleb; Eniang, Edem A; Baha El Din, Sherif; Lemmon, Alan R; Burbrink, Frank T

    2014-10-01

    Africa is renowned for its biodiversity and endemicity, yet little is known about the factors shaping them across the continent. African Agama lizards (45 species) have a pan-continental distribution, making them an ideal model for investigating biogeography. Many species have evolved conspicuous sexually dimorphic traits, including extravagant breeding coloration in adult males, large adult male body sizes, and variability in social systems among colorful versus drab species. We present a comprehensive time-calibrated species tree for Agama, and their close relatives, using a hybrid phylogenetic-phylogenomic approach that combines traditional Sanger sequence data from five loci for 57 species (146 samples) with anchored phylogenomic data from 215 nuclear genes for 23 species. The Sanger data are analyzed using coalescent-based species tree inference using (*)BEAST, and the resulting posterior distribution of species trees is attenuated using the phylogenomic tree as a backbone constraint. The result is a time-calibrated species tree for Agama that includes 95% of all species, multiple samples for most species, strong support for the major clades, and strong support for most of the initial divergence events. Diversification within Agama began approximately 23 million years ago (Ma), and separate radiations in Southern, East, West, and Northern Africa have been diversifying for >10Myr. A suite of traits (morphological, coloration, and sociality) are tightly correlated and show a strong signal of high morphological disparity within clades, whereby the subsequent evolution of convergent phenotypes has accompanied diversification into new biogeographic areas. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Enterotoxins and emetic toxins production by Bacillus cereus and other species of Bacillus isolated from Soumbala and Bikalga, African alkaline fermentedfood condiments

    DEFF Research Database (Denmark)

    Ouoba, Labia Irene I.; Thorsen, Line; Varnam, Alan H.

    2008-01-01

    -hemolytic enterotoxin (NheA, NheB, NheC) and EM1 specific of emetic toxin producerswas also investigated using PCR with single pair and multiplex primers. Of 41 isolates, 29 Bacillus belonging to the species of B. cereus, Bacillus subtilis, Bacillus licheniformis and Bacillus pumilus showed haemolysis on blood agar......The ability of various species of Bacillus from fermented seeds of Parkia biglobosa known as African locust bean(Soumbala) and fermented seeds of Hibiscus sabdariffa (Bikalga) was investigated. The study included screening of the isolates by haemolysis on blood agar, detection of toxins in broth...... and during the fermentation of African locust bean using the Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCETRPLA) and the Bacillus Diarrhoeal Enterotoxin Visual Immunoassay (BDEVIA). Detection of genes encoding´cytotoxin K (CytK), haemolysin BL (Hbl A, Hbl C, Hbl D), non...

  2. Non-equilibrium estimates of gene flow inferred from nuclear genealogies suggest that Iberian and North African wall lizards (Podarcis spp. are an assemblage of incipient species

    Directory of Open Access Journals (Sweden)

    Harris D James

    2008-02-01

    Full Text Available Abstract Background The study of recently-diverged species offers significant challenges both in the definition of evolutionary entities and in the estimation of gene flow among them. Iberian and North African wall lizards (Podarcis constitute a cryptic species complex for which previous assessments of mitochondrial DNA (mtDNA and allozyme variation are concordant in describing the existence of several highly differentiated evolutionary units. However, these studies report important differences suggesting the occurrence of gene flow among forms. Here we study sequence variation in two nuclear introns, β-fibint7 and 6-Pgdint7, to further investigate overall evolutionary dynamics and test hypotheses related to species delimitation within this complex. Results Both nuclear gene genealogies fail to define species as monophyletic. To discriminate between the effects of incomplete lineage sorting and gene flow in setting this pattern, we estimated migration rates among species using both FST-based estimators of gene flow, which assume migration-drift equilibrium, and a coalescent approach based on a model of divergence with gene flow. Equilibrium estimates of gene flow suggest widespread introgression between species, but coalescent estimates describe virtually zero admixture between most (but not all species pairs. This suggests that although gene flow among forms may have occurred the main cause for species polyphyly is incomplete lineage sorting, implying that most forms have been isolated since their divergence. This observation is therefore in accordance with previous reports of strong differentiation based on mtDNA and allozyme data. Conclusion These results corroborate most forms of Iberian and North African Podarcis as differentiated, although incipient, species, supporting a gradual view of speciation, according to which species may persist as distinct despite some permeability to genetic exchange and without having clearly definable genetic

  3. Prioritizing West African medicinal plants for conservation and sustainable extraction studies based on market surveys and species distribution models

    NARCIS (Netherlands)

    van Andel, T.R.; Croft, S.; van Loon, E.E.; Quiroz, D.; Towns, A.M.; Raes, N.

    2015-01-01

    Sub-Saharan African human populations rely heavily on wild-harvested medicinal plants for their health. The trade in herbal medicine provides an income for many West African people, but little is known about the effects of commercial extraction on wild plant populations. Detailed distribution maps

  4. Prioritizing West African medicinal plants for conservation and sustainable extraction studies based on market surveys and species distribution models.

    NARCIS (Netherlands)

    Andel, van T.R.; Croft, S.; Loon, van E.E.; Quiroz Villarreal, D.K.; Towns, A.M.; Raes, N.

    2015-01-01

    Sub-Saharan African human populations rely heavily on wild-harvested medicinal plants for their health. The trade in herbal medicine provides an income for many West African people, but little is known about the effects of commercial extraction on wild plant populations. Detailed distribution maps

  5. East African cassava mosaic-like viruses from Africa to Indian ocean islands: molecular diversity, evolutionary history and geographical dissemination of a bipartite begomovirus

    Directory of Open Access Journals (Sweden)

    De Bruyn Alexandre

    2012-11-01

    Full Text Available Abstract Background Cassava (Manihot esculenta is a major food source for over 200 million sub-Saharan Africans. Unfortunately, its cultivation is severely hampered by cassava mosaic disease (CMD. Caused by a complex of bipartite cassava mosaic geminiviruses (CMG species (Family: Geminivirideae; Genus: Begomovirus CMD has been widely described throughout Africa and it is apparent that CMG's are expanding their geographical distribution. Determining where and when CMG movements have occurred could help curtail its spread and reveal the ecological and anthropic factors associated with similar viral invasions. We applied Bayesian phylogeographic inference and recombination analyses to available and newly described CMG sequences to reconstruct a plausible history of CMG diversification and migration between Africa and South West Indian Ocean (SWIO islands. Results The isolation and analysis of 114 DNA-A and 41 DNA-B sequences demonstrated the presence of three CMG species circulating in the Comoros and Seychelles archipelagos (East African cassava mosaic virus, EACMV; East African cassava mosaic Kenya virus, EACMKV; and East African cassava mosaic Cameroon virus, EACMCV. Phylogeographic analyses suggest that CMG’s presence on these SWIO islands is probably the result of at least four independent introduction events from mainland Africa occurring between 1988 and 2009. Amongst the islands of the Comoros archipelago, two major migration pathways were inferred: One from Grande Comore to Mohéli and the second from Mayotte to Anjouan. While only two recombination events characteristic of SWIO islands isolates were identified, numerous re-assortments events were detected between EACMV and EACMKV, which seem to almost freely interchange their genome components. Conclusions Rapid and extensive virus spread within the SWIO islands was demonstrated for three CMG complex species. Strong evolutionary or ecological interaction between CMG species may explain

  6. North African hybrid sparrows (Passer domesticus, P. hispaniolensis) back from oblivion - ecological segregation and asymmetric mitochondrial introgression between parental species.

    Science.gov (United States)

    Ait Belkacem, Abdelkrim; Gast, Oliver; Stuckas, Heiko; Canal, David; LoValvo, Mario; Giacalone, Gabriele; Päckert, Martin

    2016-08-01

    A stabilized hybrid form of the house sparrow (Passer domesticus) and the Spanish sparrow (P. hispaniolensis) is known as Passer italiae from the Italian Peninsula and a few Mediterranean islands. The growing attention for the Italian hybrid sparrow and increasing knowledge on its biology and genetic constitution greatly contrast the complete lack of knowledge of the long-known phenotypical hybrid sparrow populations from North Africa. Our study provides new data on the breeding biology and variation of mitochondrial DNA in three Algerian populations of house sparrows, Spanish sparrows, and phenotypical hybrids. In two field seasons, the two species occupied different breeding habitats: Spanish sparrows were only found in rural areas outside the cities and bred in open-cup nests built in large jujube bushes. In contrast, house sparrows bred only in the town centers and occupied nesting holes in walls of buildings. Phenotypical hybrids were always associated with house sparrow populations. House sparrows and phenotypical hybrids started breeding mid of March, and most pairs had three successive clutches, whereas Spanish sparrows started breeding almost one month later and had only two successive clutches. Mitochondrial introgression is strongly asymmetric because about 75% of the rural Spanish sparrow population carried house sparrow haplotypes. In contrast, populations of the Italian hybrid form, P. italiae, were genetically least diverse among all study populations and showed a near-fixation of house sparrow haplotypes that elsewhere were extremely rare or that were even unique for the Italian Peninsula. Such differences between mitochondrial gene pools of Italian and North African hybrid sparrow populations provide first evidence that different demographic histories have shaped the extant genetic diversity observed on both continents.

  7. Inference of a Geminivirus-Host Protein-Protein Interaction Network through Affinity Purification and Mass Spectrometry Analysis.

    Science.gov (United States)

    Wang, Liping; Ding, Xue; Xiao, Jiajing; Jiménez-Gόngora, Tamara; Liu, Renyi; Lozano-Durán, Rosa

    2017-09-25

    Viruses reshape the intracellular environment of their hosts, largely through protein-protein interactions, to co-opt processes necessary for viral infection and interference with antiviral defences. Due to genome size constraints and the concomitant limited coding capacity of viruses, viral proteins are generally multifunctional and have evolved to target diverse host proteins. Inference of the virus-host interaction network can be instrumental for understanding how viruses manipulate the host machinery and how re-wiring of specific pathways can contribute to disease. Here, we use affinity purification and mass spectrometry analysis (AP-MS) to define the global landscape of interactions between the geminivirus Tomato yellow leaf curl virus (TYLCV) and its host Nicotiana benthamiana . For this purpose, we expressed tagged versions of each of TYLCV-encoded proteins (C1/Rep, C2/TrAP, C3/REn, C4, V2, and CP) in planta in the presence of the virus. Using a quantitative scoring system, 728 high-confidence plant interactors were identified, and the interaction network of each viral protein was inferred; TYLCV-targeted proteins are more connected than average, and connect with other proteins through shorter paths, which would allow the virus to exert large effects with few interactions. Comparative analyses of divergence patterns between N. benthamiana and potato, a non-host Solanaceae , showed evolutionary constraints on TYLCV-targeted proteins. Our results provide a comprehensive overview of plant proteins targeted by TYLCV during the viral infection, which may contribute to uncovering the underlying molecular mechanisms of plant viral diseases and provide novel potential targets for anti-viral strategies and crop engineering. Interestingly, some of the TYLCV-interacting proteins appear to be convergently targeted by other pathogen effectors, which suggests a central role for these proteins in plant-pathogen interactions, and pinpoints them as potential targets to

  8. Comparative analysis of components incorporated in conservation priority assessments: a case study based on South African species of terrestrial mammals

    CSIR Research Space (South Africa)

    Keith, M

    2007-04-01

    Full Text Available of South African Mammals. These results suggest that the two conservation priority assessment techniques used in the present study may represent a practical and quantitative method for determining regional conservation priorities, and include measures...

  9. Geminiviruses Subvert Ubiquitination by Altering CSN-Mediated Derubylation of SCF E3 Ligase Complexes and Inhibit Jasmonate Signaling in Arabidopsis thaliana[C][W

    Science.gov (United States)

    Lozano-Durán, Rosa; Rosas-Díaz, Tabata; Gusmaroli, Giuliana; Luna, Ana P.; Taconnat, Ludivine; Deng, Xing Wang; Bejarano, Eduardo R.

    2011-01-01

    Viruses must create a suitable cell environment and elude defense mechanisms, which likely involves interactions with host proteins and subsequent interference with or usurpation of cellular machinery. Here, we describe a novel strategy used by plant DNA viruses (Geminiviruses) to redirect ubiquitination by interfering with the activity of the CSN (COP9 signalosome) complex. We show that geminiviral C2 protein interacts with CSN5, and its expression in transgenic plants compromises CSN activity on CUL1. Several responses regulated by the CUL1-based SCF ubiquitin E3 ligases (including responses to jasmonates, auxins, gibberellins, ethylene, and abscisic acid) are altered in these plants. Impairment of SCF function is confirmed by stabilization of yellow fluorescent protein–GAI, a substrate of the SCFSLY1. Transcriptomic analysis of these transgenic plants highlights the response to jasmonates as the main SCF-dependent process affected by C2. Exogenous jasmonate treatment of Arabidopsis thaliana plants disrupts geminivirus infection, suggesting that the suppression of the jasmonate response might be crucial for infection. Our findings suggest that C2 affects the activity of SCFs, most likely through interference with the CSN. As SCFs are key regulators of many cellular processes, the capability of viruses to selectively interfere with or hijack the activity of these complexes might define a novel and powerful strategy in viral infections. PMID:21441437

  10. The snake family Psammophiidae (Reptilia: Serpentes): phylogenetics and species delimitation in the African sand snakes (Psammophis Boie, 1825) and allied genera.

    Science.gov (United States)

    Kelly, Christopher M R; Barker, Nigel P; Villet, Martin H; Broadley, Donald G; Branch, William R

    2008-06-01

    This study constitutes the first evolutionary investigation of the snake family Psammophiidae--the most widespread, most clearly defined, yet perhaps the taxonomically most problematic of Africa's family-level snake lineages. Little is known of psammophiid evolutionary relationships, and the type genus Psammophis is one of the largest and taxonomically most complex of the African snake genera. Our aims were to reconstruct psammophiid phylogenetic relationships and to improve characterisation of species boundaries in problematic Psammophis species complexes. We used approximately 2500 bases of DNA sequence from the mitochondrial and nuclear genomes, and 114 terminals covering all psammophiid genera and incorporating approximately 75% of recognised species and subspecies. Phylogenetic reconstructions were conducted primarily in a Bayesian framework and we used the Wiens/Penkrot protocol to aid species delimitation. Rhamphiophis is diphyletic, with Rhamphiophis acutus emerging sister to Psammophylax. Consequently we transfer the three subspecies of Rhamphiophis acutus to the genus Psammophylax. The monotypic genus Dipsina is sister to Psammophis. The two species of Dromophis occupy divergent positions deeply nested within Psammophis, and we therefore relegate Dromophis to the synonymy of Psammophis. Our results allow division of the taxonomically problematic Psammophis 'sibilans' species complex into two monophyletic entities, provisionally named the 'phillipsii' and 'subtaeniatus' complexes. Within these two clades we found support for the status of many existing species, but not for a distinction between P.p. phillipsii and P. mossambicus. Additionally, P. cf. phillipsii occidentalis deserves species status as the sister taxon of P. brevirostris.

  11. Petrocephalus boboto and Petrocephalus arnegardi, two new species of African electric fish (Osteoglossomorpha, Mormyridae from the Congo River basin

    Directory of Open Access Journals (Sweden)

    Sebastien Lavoue

    2014-04-01

    Full Text Available A specimen of the African weakly electric fish genus Petrocephalus (Osteoglossomorpha, Mormyridae collected in the Congo River at Yangambi, Orientale Province, Democratic Republic of Congo, is described as a new species. Petrocephalus boboto sp. n. can be distinguished from other Central African species of Petrocephalus by a combination of the following characteristics: three distinct black spots on the body, one at the origin of the pectoral fin, one at the origin of the caudal fin and one below the anterior base of the dorsal fin; Nakenrosette and Khelrosette electroreceptor clusters distinct on head but Augenrosette cluster reduced in size; 23 branched dorsal rays, 34 branched anal rays, and electric organ discharge waveform triphasic. Petrocephalus boboto sp. n. most closely resembles the holotype of Petrocephalus binotatus but is easily distinguished from it by its smaller mouth. A comparative molecular analysis including 21 other Petrocephalus species shows Petrocephalus boboto sp. n. to be genetically distinctive and to represent a deep lineage in the genus. Two specimens of Petrocephalus collected at Yangambi are morphologically similar and genetically closely related to specimens previously assigned to Petrocephalus binotatus, collected in the northwestern Congo River basin within Odzala-Kokua National Park, Republic of the Congo. This prompts us to formally describe a new species from these collections, Petrocephalus arnegardi sp. n., that, although similar to the holotype of Petrocephalus binotatus, can be distinguished from it by its smaller mouth and shorter interorbital width.

  12. Resistance gene analogs involved in tolerant cassava--geminivirus interaction that shows a recovery phenotype.

    Science.gov (United States)

    Louis, Bengyella; Rey, Chrissie

    2015-12-01

    The current literature describes recovery from virus-induced symptoms as a RNA silencing defense, but immunity-related genes, including the structurally specific resistance gene analogs (RGAs) that may play a key role in tolerance and recovery is not yet reported. In this study, the transcriptome data of tolerant cassava TME3 (which exhibits a recovery phenotype) and susceptible cassava T200 infected with South African cassava mosaic virus were explored for RGAs. Putative resistance protein analogs (RPAs) with amide-like indole-3-acetic acid-Ile-Leu-Arg (IAA-ILR) and leucine-rich repeat (LRR)-kinase conserved domains were unique to TME3. Common responsive RPAs in TME3 and T200 were the dirigent-like protein, coil-coil nucleotide-binding site (NBS) and toll-interleukin-resistance, disease resistance zinc finger chromosome condensation-like protein (DZC), and NBS-apoptosis repressor with caspase recruitment (ARC)-LRR domains. Mutations in RPAs in the MHD motif of the NBS-ARC2 subdomain associated with the recovery phase in TME3 were observed. Additionally, a cohort of 25 RGAs mined solely during the recovery process in TME3 was identified. Phylogenetic and expression analyses support that diverse RGAs are differentially expressed during tolerance and recovery. This study reveals that in cassava, a perennial crop, RGAs participate in tolerance and differentially accumulate during recovery as a complementary defense mechanism to natural occurring RNA silencing to impair viral replication.

  13. Biological Invasions of Geminiviruses: Case Study of TYLCV and Bemisia tabaci in Reunion Island

    Directory of Open Access Journals (Sweden)

    Jean-Michel Lett

    2012-12-01

    Full Text Available In the last 20 years, molecular ecology approaches have proven to be extremely useful to identify and assess factors associated with viral emerging diseases, particularly in economically and socially important tropical crops such as maize (maize streak disease and cassava (cassava mosaic disease. Molecular ecology approaches were applied in Reunion Island to analyze the epidemic of tomato yellow leaf curl disease, which has been affecting the island since the end of the 1990s. Before the invasive biotype B (currently known as Middle East-Asia Minor 1 cryptic species of Bemisia tabaci spread across the world, Reunion Island (South West Indian Ocean only hosted an indigenous biotype of B. tabaci, Ms (currently known as Indian Ocean cryptic species. Wild hybrids between invasive and indigenous species were subsequently characterized over multiple generations. Endosymbiont analysis of the hybrid population indicated that matings were non-random. Similarly, while no indigenous begomoviruses have ever been reported on Reunion Island, the two main strains of one of the most damaging and emerging plant viruses in the world, the Mild and Israel strains of the Tomato yellow leaf curl virus (TYLCV-Mld and TYLCV-IL, were introduced in 1997 and 2004 respectively. While these introductions extensively modified the agricultural landscape of Reunion Island, they also provided an invaluable opportunity to study the ecological and genetic mechanisms involved in biological invasion and competition.

  14. From Lake Malawi Drilling: East African Climate May Have Caused Major Evolutionary Turnover in Mammalian Species During MIS 14

    Science.gov (United States)

    Johnson, Thomas; Werne, Josef

    2016-04-01

    Hominin evolution underwent important changes in the last 1.3 million years, including the extinction of Paranthropus at about 1.2 Ma, leaving Homo as the sole hominin genus. Our genus experienced a major increase in cranial capacity at about 500 ka, and our species, H. sapiens, first appeared at ~200 ka. There was a major turnover in mammalian species in East Africa between 540 and 400 ka, favoring descendants of smaller size and less specialized diet. An understanding of what drove evolution in these directions is fundamental to understanding the development of modern H. sapiens. Climate certainly played a role, for it is the principal factor that influences the distribution of vegetation and habitability on the landscape. We present a 1.3 million year record of temperature and hydroclimate in the basin of Lake Malawi, the second deepest lake in Africa, derived from a 380 m sediment sequence taken from a water depth of 590 m by the Lake Malawi Drilling Project. Seismic reflection profiles used to select the site portray an undisturbed sedimentary section that was not impacted by erosion, turbidity currents or mass wasting events. Sediment samples were analyzed to produce records of temperature (TEX86) and aridity (Ca content and leaf wax δ13C). The temperature record displays progressively larger amplitude glacial-interglacial variations from MIS 13 (~500 ka) to MIS 5 (~125 ka). Intervals of low Ca abundance, which reflect lake high stands, correlate with times of depleted δ13Cwax and relatively warm temperatures. The Malawi basin experienced warm, wet interglacials and cooler (by about 2 - 4°C), dry glacial periods, with roughly a 100 ky periodicity since the Mid-Pleistocene Transition (MPT), about 900 ka. The paleoclimate record from Lake Malawi sediments portrays a transition from a highly variable and predominantly arid climate prior to 900 ka to a progressively more humid environment after the MPT dominated by 100 ky cycles consisting of warm, wet

  15. Unregulated aquaculture and invasive alien species: a case study of the African Catfish Clarias gariepinus in Vembanad Lake (Ramsar Wetland, Kerala, India

    Directory of Open Access Journals (Sweden)

    K. Krishnakumar

    2011-05-01

    Full Text Available Indiscriminate and illegal farming of the African Catfish Clarias gariepinus, in central Kerala has now resulted in the escape and spread of the species into Vembanad Lake, a large brackish water wetland and inland fish diversity hotspot. We collected 17 individuals of C. gariepinus ranging in size from 200 to 750 mm from different locations in the southern sector of the lake during a field survey conducted in 2007. Samples comprised of mature specimens of both sexes indicating their reproductive potential in the study area. The possible impacts of spread of C. gariepinus into natural water bodies of Kerala, especially the Vembanad Lake, and options for their management are discussed.

  16. A revision of the African genera Paropsiopsis and smeathmannia (passifloraceae - paropsieae), including a new species of paropsiopsis from Cameroon.

    NARCIS (Netherlands)

    Vos, de J.M.; Breteler, F.J.

    2009-01-01

    The African genera Paropsiopsis Engl. and Smeathmannia R.Br. (Passifloraceae ¿ Paropsieae) are revised. The two genera are well separated based on the presence or absence of a second, annuliform, corona, as well as the number of stamens and curvature of their filaments. An overview of important

  17. Karyotype and Mapping of Repetitive DNAs in the African Butterfly Fish Pantodon buchholzi, the Sole Species of the Family Pantodontidae

    Czech Academy of Sciences Publication Activity Database

    Ráb, Petr; Yano, C. F.; Lavoué, S.; Jegede, O. I.; Bertollo, L.A.C.; Ezaz, T.; Majtánová, Zuzana; de Oliveira, E. A.; Cioffi, M.B.

    2016-01-01

    Roč. 149, č. 4 (2016), s. 312-320 ISSN 1424-8581 R&D Projects: GA ČR GA14-02940S Institutional support: RVO:67985904 Keywords : African butterfly fish * conventional staining techniques * fluorescence in situ hybridization Subject RIV: EG - Zoology Impact factor: 1.354, year: 2016

  18. Digitonthophagus Balthasar, 1959: taxonomy, systematics, and morphological phylogeny of the genus revealing an African species complex (Coleoptera: Scarabaeidae: Scarabaeinae).

    Science.gov (United States)

    Génier, François; Moretto, Philippe

    2017-03-31

    The taxonomy and systematics of the genus Digitonthophagus Balthasar (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) is revised. A detailed study of the male genitalia combined with external morphology suggests that the variability, previously recognized, for D. gazella is hiding a species complex within the Afrotropical region and the Arabian Peninsula. The current study recognizes 16 species; 13 from the Afrotropical region and Arabian Peninsula and three from the eastern portion of the Saharo-Arabian region and the continental Indomalayan region. Species are organized into six species groups based on the results of the morphology-based phylogenetic analysis. The following 12 species are described as new: D. aksumensis Génier new species; D. biflagellatus Génier new species; D. dilatatus Génier new species; D. eucatta Génier new species; D. falciger Génier new species; D. fimator Génier new species; D. namaquensis Génier new species; D. petilus Génier new species; D. sahelicus Moretto new species; D. uks Génier new species; D. ulcerosus Génier new species; and D. viridicollis Génier new species. In order to stabilize nomenclature, lectotypes are designated for Scarabaeus bonasus Fabricius, 1775; Scarabaeus catta Fabricius, 1787, and Onthophagus gazella lusinganus d'Orbigny. A neotype is designated for Scarabaeus dorcas Olivier, 1789 whose status and synonymy need to be altered in order to clarify the status of Scarabaeus gazella auctorum, the widely introduced species with economic importance. A naming scheme is presented for the sclerites of the internal sac. External and male genitalia are illustrated and distribution maps are provided for each species.

  19. A new brachypterous species of Phoberus MacLeay (Coleoptera: Trogidae) and status changes of species in the East African P. nigrociliatus group.

    Science.gov (United States)

    Strümpher, Werner P; Scholtz, Clarke H

    2017-01-06

    A new brachypterous species, Phoberus nyikanus Strümpher (Coleoptera: Trogidae), is described from Malawi. In addition, three status changes are proposed: Phoberus nigrociliatus (Kolbe) from the Ethiopian highlands, P. nyansanus (Haaf) from central East Africa, and P. nyassicus (Haaf) from southern Tanzanian mountains are elevated to species level. A key is provided to aid in the identification of members of the P. nigrociliatus group, and the species in the group are illustrated by photographs. This brings the total number of species in the genus to 44.

  20. Identification of the same polyomavirus species in different African horseshoe bat species is indicative of short-range host-switching events.

    Science.gov (United States)

    Carr, Michael; Gonzalez, Gabriel; Sasaki, Michihito; Dool, Serena E; Ito, Kimihito; Ishii, Akihiro; Hang'ombe, Bernard M; Mweene, Aaron S; Teeling, Emma C; Hall, William W; Orba, Yasuko; Sawa, Hirofumi

    2017-10-06

    Polyomaviruses (PyVs) are considered to be highly host-specific in different mammalian species, with no well-supported evidence for host-switching events. We examined the species diversity and host specificity of PyVs in horseshoe bats (Rhinolophus spp.), a broadly distributed and highly speciose mammalian genus. We annotated six PyV genomes, comprising four new PyV species, based on pairwise identity within the large T antigen (LTAg) coding region. Phylogenetic comparisons revealed two instances of highly related PyV species, one in each of the Alphapolyomavirus and Betapolyomavirus genera, present in different horseshoe bat host species (Rhinolophus blasii and R. simulator), suggestive of short-range host-switching events. The two pairs of Rhinolophus PyVs in different horseshoe bat host species were 99.9 and 88.8 % identical with each other over their respective LTAg coding sequences and thus constitute the same virus species. To corroborate the species identification of the bat hosts, we analysed mitochondrial cytb and a large nuclear intron dataset derived from six independent and neutrally evolving loci for bat taxa of interest. Bayesian estimates of the ages of the most recent common ancestors suggested that the near-identical and more distantly related PyV species diverged approximately 9.1E4 (5E3-2.8E5) and 9.9E6 (4E6-18E6) years before the present, respectively, in contrast to the divergence times of the bat host species: 12.4E6 (10.4E6-15.4E6). Our findings provide evidence that short-range host-switching of PyVs is possible in horseshoe bats, suggesting that PyV transmission between closely related mammalian species can occur.

  1. Occurrence of nodulation in unexplored leguminous trees native to the West African tropical rainforest and inoculation response of native species useful in reforestation.

    Science.gov (United States)

    Diabate, Moussa; Munive, Antonio; de Faria, Sérgio Miana; Ba, Amadou; Dreyfus, Bernard; Galiana, Antoine

    2005-04-01

    Despite the abundance and diversity of timber tree legumes in the West African rainforest, their ability to form nitrogen-fixing nodules in symbiosis with rhizobia, and their response to rhizobial inoculation, remain poorly documented. In the first part of this study the occurrence of nodulation was determined in 156 leguminous species growing in six natural forest areas in Guinea, mostly mature trees. In the second part, an in situ experiment of rhizobial inoculation was performed on eight selected tree species belonging to three genera: Albizia, Erythrophleum and Millettia. Of the 97 plant species and 14 genera that had never been examined before this study, 31 species and four genera were reported to be nodulated. After 4 months of growing in a nursery and a further 11 months after transplantation of plants to the field, we observed a highly significant (P < 0.001) and positive effect of inoculation with Bradyrhizobium sp. strains on the growth of the eight tree species tested. The importance of determining the nodulation ability of unexplored local trees and subsequently using this information for inoculation in reforestation programmes was demonstrated. Copyright New Phytologist (2005).

  2. Phylogeographic patterning among two codistributed shrimp species (Crustacea: Decapoda: Palaemonidae reveals high levels of connectivity across biogeographic regions along the South African coast.

    Directory of Open Access Journals (Sweden)

    Louisa E Wood

    Full Text Available We compare the genetic structuring and demographic history of two sympatric caridean shrimp species with distinct life history traits, one amphidromous species Palaemon capensis and one marine/estuarine species Palaemon peringueyi, in the historical biogeographical context of South Africa. A total of 103 specimens of P. capensis collected from 12 localities and 217 specimens of P. peringueyi collected from 24 localities were sequenced for the mitochondrial cytochrome oxidase one (CO1 locus. Results from analyses of molecular variance (AMOVA, pairwise ΦST comparisons and haplotype networks demonstrate weak to moderate genetic differentiation in P. capensis and P. peringueyi respectively. P. peringueyi exhibits partial isolation between populations associated with distinct biogeographic regions, likely driven by the region's oceanography. However, there is minimal evidence for the occurrence of discrete regional evolutionary lineages. This demonstrated lack of genetic differentiation is consistent with a marine, highly dispersive planktonic phase in both the amphidromous P. capensis and the marine/estuarine P. peringueyi. Bayesian skyline plots, mismatch expansions and time since expansion indicate that both species maintained stable populations during the Last Glacial Maximum (LGM, unlike other southern African aquatic species.

  3. Development and characterization of 10 microsatellite markers in the Cape horseshoe bat, Rhinolophus capensis (Chiroptera, Rhinolophidae) and cross-amplification in southern African Rhinolophus species.

    Science.gov (United States)

    Nesi, Nicolas; Jacobs, David S; Feldheim, Kevin; Bishop, Jacqueline M

    2015-09-26

    The Cape horseshoe bat, Rhinolophus capensis, is endemic to the Cape region of South Africa. Coalescent analysis of mitochondrial DNA sequence data suggests extensive historical gene flow between populations despite strong geographic variation of their echolocation call phenotype. Nevertheless the fine-scale genetic structure and evolutionary ecology of R. capensis remains poorly understood. Here we describe the development of 10 novel polymorphic microsatellite loci to investigate of the dispersal ecology of R. capensis and to facilitate taxonomic studies of Rhinolophus species in southern Africa. We report 10 microsatellite primer pairs that consistently amplify scorable and polymorphic loci across 12 African rhinolophid species. Initial analysis of two populations of R. capensis from South Africa revealed moderate to high levels of allelic variation with 4-14 alleles per locus and observed heterozygosities of 0.450-0.900. No evidence of linkage disequilibrium was observed and eight of the loci showed no departure from Hardy-Weinberg equilibrium. Cross-species utility of these markers revealed consistently amplifiable polymorphic loci in eleven additional rhinolophid species. The cross-amplification success of the microsatellites developed here provides a cost-effective set of population genetic marker for the study of rhinolophid evolutionary ecology and conservation in southern Africa.

  4. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    Science.gov (United States)

    Ulrich, Werner; Lens, Luc; Tobias, Joseph A; Habel, Jan C

    2016-01-01

    Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  5. Contrasting Patterns of Species Richness and Functional Diversity in Bird Communities of East African Cloud Forest Fragments.

    Directory of Open Access Journals (Sweden)

    Werner Ulrich

    Full Text Available Rapid fragmentation and degradation of large undisturbed habitats constitute major threats to biodiversity. Several studies have shown that populations in small and highly isolated habitat patches are prone to strong environmental and demographic stochasticity and increased risk of extinction. Based on community assembly theory, we predict recent rapid forest fragmentation to cause a decline in species and functional guild richness of forest birds combined with a high species turnover among habitat patches, and well defined dominance structures, if competition is the major driver of community assembly. To test these predictions, we analysed species co-occurrence, nestedness, and competitive strength to infer effects of interspecific competition, habitat structure, and species' traits on the assembly of bird species communities from 12 cloud forest fragments in southern Kenya. Our results do not point to a single ecological driver of variation in species composition. Interspecific competition does not appear to be a major driver of species segregation in small forest patches, while its relative importance appears to be higher in larger ones, which may be indicative for a generic shift from competition-dominated to colonisation-driven community structure with decreasing fragment size. Functional trait diversity was independent of fragment size after controlling for species richness. As fragmentation effects vary among feeding guilds and habitat generalists, in particular, tend to decline in low quality forest patches, we plead for taking species ecology fully into account when predicting tropical community responses to habitat change.

  6. Bio-indicator species and Central African rain forest refuges in the Campo-Ma'an area, Cameroon

    NARCIS (Netherlands)

    Tchouto, M.G.P.; de Wilde, J.J.F.E.; de Boer, W.F.; van der Maesen, L.J.G.; Cleef, A.M.

    2009-01-01

    This study aims to examine the geographical position of late Pleistocene forest refuges in the tropical lowland rain forest in southern Cameroon by analysing the distribution of 178 selected bio-indicator species. We studied the distribution patterns of these species, such as strict and narrow

  7. Rocky shores of a major southern African Marine Protected Area are almost free from intertidal invertebrate alien species

    Directory of Open Access Journals (Sweden)

    Hanlie Malherbe

    2014-05-01

    Full Text Available A major threat to marine ecosystems is the establishment and proliferation of invasive alien species. This study addresses gaps in our knowledge regarding marine alien invertebrate species in the Kogelberg Biosphere Reserve (KBR and adjacent Betty’s Bay Marine Protected Area (MPA in the Western Cape of South Africa, together a potentially important area for south-coast marine conservation. Understanding the distribution and geographical expansion of these species is critical for conservation planning. A quantitative systematic survey of the intertidal rocky shore region was undertaken. The mytilid Mediterranean mussel, Mytilus galloprovincialis, and the bryozoan Watersipora subtorquata were the only alien species recorded along the coastline, which included the MPA. The abundance of M. galloprovincialis was significantly higher outside the MPA, and the abundance of W. subtorquata was significantly higher inside the MPA. With only two alien species recorded, the Betty’s Bay MPA and its surroundings support relatively few marine alien species with regards to rocky shore invertebrate biodiversity. Conservation implications: It is important that the Betty’s Bay MPA and its adjacent coastline maintain its current status as an area with relatively few marine alien species. The conservation implications on management require routine surveys of this region to detect early introductions of any additional species.

  8. The mineral scoring technique and evaluation of indigenous browse species as natural mineral phytocentres for goats in African rangelands.

    Science.gov (United States)

    Kabasa, J D; Opuda-Asibo, J; Thinggaard, G; ter Meulen, U

    2004-05-01

    The utilization and evaluation of indigenous browse species as natural mineral phytocentres for goats was examined by the combined use of mineral concentrations, mineral scores, browse accessibility and abundance in the Ankole rangeland, Uganda. The species Grewia bicolor and Carissa edulis with > 140% mineral scores and > 70% accessibility were the most valuable mineral phytocentres and were the victims of overgrazing. Acacia albida and Acacia abyssinica with > 130% mineral scores but genus Acacia and lowest (5.3%) in Dichrostachsys. Browse accessibility was < 35%, in 69.2% of species. Acacia hockii was the most abundant species (24.5%) but had the lowest mineral score (17.7%). Browse species (90-100%) were deficient in Fe, Mn, Cu and Zn. The combined use of mineral concentrations and mineral scoring technique was superior to the use of mineral concentrations alone in defining mineral adequacy, deficiency and supply potential, making the mineral scoring technique a valuable tool in browse management.

  9. Impact of habitat degradation on species diversity and nest abundance of five African stingless bee species in a tropical rainforest of Kenya

    NARCIS (Netherlands)

    Kiatoko, Nkoba; Raina, Suresh Kumar; Langevelde, Van Frank

    2017-01-01

    Natural habitat degradation often involves the reduction or disappearance of bee species. In Africa, stingless bees are hunted for honey, which is used as food, for medicinal purposes, and for traditional rituals. Severe habitat degradation due to human settlement is hypothesized to have a negative

  10. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna.

    Science.gov (United States)

    Zwerts, J A; Prins, H H T; Bomhoff, D; Verhagen, I; Swart, J M; de Boer, W F

    2015-01-01

    South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling) by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon) and a species that is frequently found outside grazing lawns (Hyparrhenia hirta), and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns.

  11. Competition between a Lawn-Forming Cynodon dactylon and a Tufted Grass Species Hyparrhenia hirta on a South-African Dystrophic Savanna.

    Directory of Open Access Journals (Sweden)

    J A Zwerts

    Full Text Available South African savanna grasslands are often characterised by indigestible tufted grass species whereas lawn grasses are far more desirable in terms of herbivore sustenance. We aimed to investigate the role of nutrients and/or the disturbance (grazing, trampling by herbivores on the formation of grazing lawns. We conducted a series of common garden experiments to test the effect of nutrients on interspecific competition between a typical lawn-forming grass species (Cynodon dactylon and a species that is frequently found outside grazing lawns (Hyparrhenia hirta, and tested for the effect of herbivore disturbance in the form of trampling and clipping. We also performed a vegetation and herbivore survey to apply experimentally derived insights to field observations. Our results showed that interspecific competition was not affected by soil nutrient concentrations. C. dactylon did show much more resilience to disturbance than H. hirta, presumably due to the regenerative capacity of its rhizomes. Results from the field survey were in line with these findings, describing a correlation between herbivore pressure and C. dactylon abundance. We conclude that herbivore disturbance, and not soil nutrients, provide C. dactylon with a competitive advantage over H. hirta, due to vegetative regeneration from its rhizomes. This provides evidence for the importance of concentrated, high herbivore densities for the creation and maintenance of grazing lawns.

  12. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

    Directory of Open Access Journals (Sweden)

    Jean-François Bastin

    Full Text Available Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing. However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass.Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood.Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity

  13. Wood Specific Gravity Variations and Biomass of Central African Tree Species: The Simple Choice of the Outer Wood.

    Science.gov (United States)

    Bastin, Jean-François; Fayolle, Adeline; Tarelkin, Yegor; Van den Bulcke, Jan; de Haulleville, Thales; Mortier, Frederic; Beeckman, Hans; Van Acker, Joris; Serckx, Adeline; Bogaert, Jan; De Cannière, Charles

    2015-01-01

    Wood specific gravity is a key element in tropical forest ecology. It integrates many aspects of tree mechanical properties and functioning and is an important predictor of tree biomass. Wood specific gravity varies widely among and within species and also within individual trees. Notably, contrasted patterns of radial variation of wood specific gravity have been demonstrated and related to regeneration guilds (light demanding vs. shade-bearing). However, although being repeatedly invoked as a potential source of error when estimating the biomass of trees, both intraspecific and radial variations remain little studied. In this study we characterized detailed pith-to-bark wood specific gravity profiles among contrasted species prominently contributing to the biomass of the forest, i.e., the dominant species, and we quantified the consequences of such variations on the biomass. Radial profiles of wood density at 8% moisture content were compiled for 14 dominant species in the Democratic Republic of Congo, adapting a unique 3D X-ray scanning technique at very high spatial resolution on core samples. Mean wood density estimates were validated by water displacement measurements. Wood density profiles were converted to wood specific gravity and linear mixed models were used to decompose the radial variance. Potential errors in biomass estimation were assessed by comparing the biomass estimated from the wood specific gravity measured from pith-to-bark profiles, from global repositories, and from partial information (outer wood or inner wood). Wood specific gravity profiles from pith-to-bark presented positive, neutral and negative trends. Positive trends mainly characterized light-demanding species, increasing up to 1.8 g.cm-3 per meter for Piptadeniastrum africanum, and negative trends characterized shade-bearing species, decreasing up to 1 g.cm-3 per meter for Strombosia pustulata. The linear mixed model showed the greater part of wood specific gravity variance was

  14. Molecular identification and safety of Bacillus species involved in the fermentation of African oil beans (Pentaclethra macrophylla Benth) for production of Ugba.

    Science.gov (United States)

    Ahaotu, I; Anyogu, A; Njoku, O H; Odu, N N; Sutherland, J P; Ouoba, L I I

    2013-03-01

    Molecular identification of Bacillus spp. involved in the fermentation of African oil bean seeds for production of Ugba, as well as ability of the Bacillus spp. isolated to produce toxins, were investigated. Forty-nine bacteria were isolated from Ugba produced in different areas of South Eastern Nigeria and identified by phenotyping and sequencing of 16S rRNA, gyrB and rpoB genes. Genotypic diversities at interspecies and intraspecies level of the isolates were screened by PCR amplification of the 16S-23S rDNA intergenic transcribed spacer (ITS-PCR) and repetitive sequence-based PCR (rep-PCR). The ability of the bacteria to produce toxins was also investigated by detection of genes encoding production of haemolysin BL (HblA, HblC, HblD), non-haemolytic enterotoxin (NheA, NheB, NheC), cytotoxin K (CytK) and emetic toxin (EM1) using PCR with specific primers. Moreover, a Bacillus cereus Enterotoxin Reverse Passive Latex Agglutination test kit (BCET-RPLA) was used to screen ability of the isolates to produce haemolysin in broth and during fermentation of African oil bean seeds. The isolates were characterized as motile, rod-shaped, endospore forming, catalase positive, Gram-positive bacteria. They were identified as Bacillus cereus sensu lato (42), Lysinibacillus xylanilyticus (3), Bacillus clausii (1), Bacillus licheniformis (1), Bacillus subtilis (1), and Bacillus safensis (1). B. cereus was the predominant Bacillus species and was present in all samples studied. Using ITS-PCR, interspecies diversity was observed among isolates, with six clusters representing each of the pre-cited species. Rep-PCR was more discriminatory (eight clusters) and allowed further differentiation at intraspecies level for the B. cereus and L. xylanilyticus isolates with two genotypes for each species. Genes encoding production of non-haemolytic enterotoxin (NheA, NheB, NheC) and cytotoxin K (CytK) genes were detected in all B. cereus isolates, while Hbl genes (HblA, HblC, HblD) were

  15. Documenting biogeographical patterns of African timber species using herbarium records: a conservation perspective based on native trees from Angola.

    Science.gov (United States)

    Romeiras, Maria M; Figueira, Rui; Duarte, Maria Cristina; Beja, Pedro; Darbyshire, Iain

    2014-01-01

    In many tropical regions the development of informed conservation strategies is hindered by a dearth of biodiversity information. Biological collections can help to overcome this problem, by providing baseline information to guide research and conservation efforts. This study focuses on the timber trees of Angola, combining herbarium (2670 records) and bibliographic data to identify the main timber species, document biogeographic patterns and identify conservation priorities. The study recognized 18 key species, most of which are threatened or near-threatened globally, or lack formal conservation assessments. Biogeographical analysis reveals three groups of species associated with the enclave of Cabinda and northwest Angola, which occur primarily in Guineo-Congolian rainforests, and evergreen forests and woodlands. The fourth group is widespread across the country, and is mostly associated with dry forests. There is little correspondence between the spatial pattern of species groups and the ecoregions adopted by WWF, suggesting that these may not provide an adequate basis for conservation planning for Angolan timber trees. Eight of the species evaluated should be given high conservation priority since they are of global conservation concern, they have very restricted distributions in Angola, their historical collection localities are largely outside protected areas and they may be under increasing logging pressure. High conservation priority was also attributed to another three species that have a large proportion of their global range concentrated in Angola and that occur in dry forests where deforestation rates are high. Our results suggest that timber tree species in Angola may be under increasing risk, thus calling for efforts to promote their conservation and sustainable exploitation. The study also highlights the importance of studying historic herbarium collections in poorly explored regions of the tropics, though new field surveys remain a priority to

  16. Impacts of the diversity of traditional uses and potential economic value on food tree species conservation status: case study of African bush mango trees (Irvingiaceae) in the Dahomey Gap (West Africa).

    NARCIS (Netherlands)

    Vihotogbé, R.; Kakai, R.G.; Bongers, F.; Andel, van T.; Berg, van den R.G.; Sinsin, B.; Sosef, M.S.M.

    2014-01-01

    Background and aims – Bitter and sweet African bush mango trees belong to the family Irvingiaceae and produce valuable non-timber forest products in humid lowland areas of West and Central Africa. The bitter and sweet types are treated as distinct taxa at the variety or species level. They have not

  17. Specific and generic stem biomass and volume models of tree species in a West African tropical semi-deciduous forest

    DEFF Research Database (Denmark)

    Goussanou, Cédric A.; Guendehou, Sabin; Assogbadjo, Achille E.

    2016-01-01

    The quantification of the contribution of tropical forests to global carbon stocks and climate change mitigation requires availability of data and tools such as allometric equations. This study made available volume and biomass models for eighteen tree species in a semi-deciduous tropical forest...... enabled to conclude that the non-destructive sampling was a good approach to determining reliable basic wood density. The comparative analysis of species-specific models in this study with selected generic models for tropical forests indicated low probability to identify effective generic models with good...

  18. Snapshot Serengeti, high-frequency annotated camera trap images of 40 mammalian species in an African savanna

    OpenAIRE

    Swanson, Alexandra; Kosmala, Margaret; Lintott, Chris; Simpson, Robert; Smith, Arfon; Packer, Craig

    2015-01-01

    Camera traps can be used to address large-scale questions in community ecology by providing systematic data on an array of wide-ranging species. We deployed 225 camera traps across 1,125 km(2) in Serengeti National Park, Tanzania, to evaluate spatial and temporal inter-species dynamics. The cameras have operated continuously since 2010 and had accumulated 99,241 camera-trap days and produced 1.2 million sets of pictures by 2013. Members of the general public classified the images via the citi...

  19. Climate change sensitivity of the African ivory nut palm, Hyphaene petersiana Klotzsch ex Mart. (Arecaceae) - a keystone species in SE Africa

    International Nuclear Information System (INIS)

    Blach-Overgaard, A; Svenning, J-C; Balslev, H

    2009-01-01

    Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined with land-use changes are thought to constitute the main threats to biodiversity in the 21st century. To be able to predict the potential impact on biodiversity, it is crucial to achieve a better insight into the controls of contemporary species ranges. Using species distribution modeling, we assessed the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables (annual precipitation and precipitation driest quarter) were of high importance. Nevertheless, latitude was the overall most dominant variable, reflecting spatial constraints on the continental-scale distribution. Of the remaining non-climatic factors, soil type and human influence were as important as the climatic factors. A future decrease in annual precipitation below 400 mm and hydrological changes towards drier conditions could cause a dramatic decline in H. petersiana populations, while the influence of temperature changes is less clear. The ongoing, unsustainable utilization pressures on this palm species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa.

  20. Comparative analysis of three different of extraction protocols of total nucleic acids of squash (Cucurbita moschata) for the diagnosis from geminivirus

    International Nuclear Information System (INIS)

    Hernandez Jimenez, Eduardo

    2008-01-01

    The geminivirus constitute an important group of plant pathogens, characterized by an unusual morphology of the viral particle and its DNA. They have a paired icosahedral cover and a small circular genome of DNA simple band that is replicated, by DNA double band, in the nucleus of the infected cell of the plant. Many researchers have focused on the development and optimization of protocols for obtaining DNA or RNA of interest, because of rapid advances in molecular biology during the second half of the XX century and the beginning of XXI century, and to that the extraction and purification of nucleic acids is the first step mainly of the procedures in this area. The objective is to compare, by means of molecular techniques, the DNA purification in squash from different ways of storage and extraction protocols of total nucleic acids of the plant, in order to improve the quality and amount of genetic matters whereupon the detection and characterization of geminivirus are realised. Three methods were compared: i. Dellaporta and collaborators (1983), ii.- Doyle and Doyle (1990) and iii.- Jose and Usha (2000). The operation of the three methods scaled downward (15 milligrams of leaf tissue) and two ways of storage were evaluated: 1.- tubes with silica gel (SG, a desiccant) and 2.- frozen to -70 degrees Celsius. The method of Jose and Usha (2000) presented technical difficulties that not permitted to scale downward, for which it should work with the purification from a gram of foliar tissue. The integrity of the total DNA was verified superior in the material stored to -70 degrees celsius for all the methods, by means of electrophoresis in gels of agarose, besides that the protocol of Dellaporta et al. (1983) tends to enrich the RNA. The readings were similar for the methods of Dellaporta et al. (1983) and Doyle and Doyle (1993), this was evidenced upon quantifying the total DNA and that is extracted at least a 30% more of DNA from material in the desiccant with respect

  1. Evidence of novel plant-species specific ammonia oxidizing bacterial clades in acidic South African fynbos soils

    CSIR Research Space (South Africa)

    Ramond, JB

    2015-02-01

    Full Text Available identified in a wide range of natural (e.g. soils, sediments, estuarine, and freshwaters) and man created or impacted habitats (e.g. wastewater treatment plants and agricultural soils). However, little is known on the plant-species association of AOBs...

  2. ‘Lactomassilus timonensis,’ a new anaerobic bacterial species isolated from the milk of a healthy African mother

    Directory of Open Access Journals (Sweden)

    A.H. Togo

    2018-01-01

    Full Text Available We here report the main characteristics of a new anaerobic bacterial genus and species ‘Lactomassilus timonensis,’ strain Marseille-P4641T (CSUR = P4641, isolated by microbial culturomics from the milk of a 35-year-old healthy lactating mother from Mali.

  3. Dispersal, dormancy and life-history tradeoffs at the individual, population and species levels in southern African Asteraceae.

    Science.gov (United States)

    de Waal, Caroli; Anderson, Bruce; Ellis, Allan G

    2016-04-01

    Dispersal and dormancy are important risk-reducing strategies in unpredictable environments. Negative covariation between these strategies is theoretically expected, but empirical evidence is limited and inconsistent. Moreover, covariation may be affected by other life-history traits and may vary across levels of biological organization. We assessed dispersal (vertical fall time of fruits, a proxy for wind dispersal ability) and dormancy (germination fractions measured during germination trials) in populations of 15 annual and 12 perennial wind-dispersed species in six Asteraceae genera from South Africa. Dormancy was higher in annuals than in perennials, whereas fall time was largely determined by evolutionary history. Controlling for phylogeny, dispersal and dormancy was negatively associated across species and life-history categories. Negative covariation between dispersal and dormancy was not evident at either the individual level (except for seed heteromorphic species) or the population level. Our study provides rare empirical support for the theoretical expectation of tradeoffs between dormancy and the alternative risk-reducing strategies, perenniality and dispersal, but refutes the expectation of increased dispersability in perennials. Although negative covariation between dispersal and dormancy at the species level appears not to be a simple consequence of upscaling individual-level mechanistic tradeoffs, our findings suggest that selection for one strategy may constrain evolution of the other. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Biomass and leaf-level gas exchange characteristics of three African savanna C4 grass species under optimum growth conditions

    NARCIS (Netherlands)

    Mantlana, K.B.; Veenendaal, E.M.; Arneth, A.; Grispen, V.; Bonyongo, C.M.; Heitkönig, I.M.A.; Lloyd, J.

    2009-01-01

    C4 savanna grass species, Digitaria eriantha, Eragrostis lehmanniana and Panicum repens, were grown under optimum growth conditions with the aim of characterizing their above- and below-ground biomass allocation and the response of their gas exchange to changes in light intensity, CO2 concentration

  5. Snapshot Serengeti, high-frequency annotated camera trap images of 40 mammalian species in an African savanna.

    Science.gov (United States)

    Swanson, Alexandra; Kosmala, Margaret; Lintott, Chris; Simpson, Robert; Smith, Arfon; Packer, Craig

    2015-01-01

    Camera traps can be used to address large-scale questions in community ecology by providing systematic data on an array of wide-ranging species. We deployed 225 camera traps across 1,125 km(2) in Serengeti National Park, Tanzania, to evaluate spatial and temporal inter-species dynamics. The cameras have operated continuously since 2010 and had accumulated 99,241 camera-trap days and produced 1.2 million sets of pictures by 2013. Members of the general public classified the images via the citizen-science website www.snapshotserengeti.org. Multiple users viewed each image and recorded the species, number of individuals, associated behaviours, and presence of young. Over 28,000 registered users contributed 10.8 million classifications. We applied a simple algorithm to aggregate these individual classifications into a final 'consensus' dataset, yielding a final classification for each image and a measure of agreement among individual answers. The consensus classifications and raw imagery provide an unparalleled opportunity to investigate multi-species dynamics in an intact ecosystem and a valuable resource for machine-learning and computer-vision research.

  6. Enrichment of Logging Gaps with a High Conservation Value Species (Pericopsis elata in a Central African Moist Forest

    Directory of Open Access Journals (Sweden)

    Dakis-Yaoba Ouédraogo

    2014-12-01

    Full Text Available In central Africa, most of the timber species require high light at the seedling stage for survival and growth. Forest managers face a regeneration shortage of these light-demanding timber species. To achieve long-term sustainability, there is a need for enrichment methods combining low cost and high species performance. The aim of this study was to assess the performance of Pericopsis elata seedlings in enriched logging gaps in Cameroon. Over five years; the survival and size of each seedling was monitored in 27 logging gaps that were either left without maintenance or cleared. Gaps were relatively small with an average total area of 155 m2. We found that planted seedlings of P. elata performed well in logging gaps. Even without any maintenance 61% of the planted seedlings survived after five years with an average annual diameter increment of 0.28 cm. P. elata appeared to be a good candidate species for enrichment in logging gaps. We demonstrated that the seedlings of P. elata tolerated a wide range of soil conditions but that their performance was strongly influenced by light availability (gap clearance, suggesting potentially improved performance of P. elata in high light environments such as in plantation or larger gaps.

  7. Stygofauna of the Canary Islands, 1. A new species of Pygocrangonyx, an amphipod genus with African affinities, from Fuerteventura

    NARCIS (Netherlands)

    Stock, Jan H.; Rondé-Broekhuizen, Brigitte L.M.

    1986-01-01

    A group of exclusively subterranean Amphipoda, the Metacrangonyx group, is distributed mainly in northwestern Africa, with peripheral isolates on the Balearic Islands and in the Sinai desert. The discovery of a new species of this group, belonging to Pygocrangonyx, a genus known from N.W. Morocco

  8. Climate change sensitivity of the African ivory nut palm, Hyphaena petersiana Klotzsch ex Mart. (arecaceae) - a keystone species in SE Africa

    DEFF Research Database (Denmark)

    Overgaard, Anne Blach; Svenning, J.-C.; Balslev, Henrik

    2009-01-01

    Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined wi...... species by humans and livestock are likely to exacerbate the negative effect of future climate changes on its populations, especially, given the expected human population increase in Africa.......Africa is the most vulnerable continent to future climate change. Profound changes are projected for southwestern Africa with increased drying, notably with delayed onset of the rainy season in September-November, and temperature increases in all seasons. The projected climate changes combined...... the climate sensitivity of the key-stone palm species Hyphaene petersiana (African ivory nut palm) in southern Africa. We tested the relative roles of climate vs. non-climatic range-controls and found that climate had a clear effect on the range of H. petersiana and that especially water-related variables...

  9. An uncommon or just an ecologically demanding species? Finding of aggregations of the brittle-star Ophiothrix maculata on the Northwest African slope

    Science.gov (United States)

    Calero, Belén; Ramos, Ana; Ramil, Fran

    2018-01-01

    Ophiuroidea constitutes the largest class of the phylum Echinodermata. It includes families with suspension-feeder behaviour that can be found in dense aggregations in all oceans worldwide. Ophiothrix maculata was known as a rare suspension-feeder brittle star, with only four records in the Eastern Central Atlantic dating from almost 100 years ago. During the ten multidisciplinary Spanish and Norwegian surveys carried out from 2004 to 2012 off Northwest Africa, between the Gibraltar Strait and the Sierra Leone border from 19 to 1888 m depth, we sampled 1298 stations. We gathered about one million individuals and 124 kg of brittle stars at 501 of the stations. Eight hundred and thirty-two specimens of Ophiothrix maculata were collected at six localities on the continental slope off Mauritania, Western Sahara and Guinea Bissau, at depths between 155 and 594 m. The Guinea Bissau samples represent the southernmost current record for the species. Even though Ophiothrix maculata has been previously recorded only in isolation, we discovered dense concentrations on the Mauritanian slope on the Wolof's Seamount (580 individuals) and off the Western Sahara, in a Lophelia pertusa reef (202 individuals). In this paper, we describe these findings and discuss the association of this species to hard-bottom habitats and high primary production areas, outside of the oxygen minimum zone (OMZ). We also analyse what other factors may explain the patchy distribution of O. maculata on the Northwest African slope.

  10. How many species and under what names? Using DNA barcoding and GenBank data for west Central African amphibian conservation.

    Directory of Open Access Journals (Sweden)

    Jessica L Deichmann

    Full Text Available Development projects in west Central Africa are proceeding at an unprecedented rate, often with little concern for their effects on biodiversity. In an attempt to better understand potential impacts of a road development project on the anuran amphibian community, we conducted a biodiversity assessment employing multiple methodologies (visual encounter transects, auditory surveys, leaf litter plots and pitfall traps to inventory species prior to construction of a new road within the buffer zone of Moukalaba-Doudou National Park, Gabon. Because of difficulties in morphological identification and taxonomic uncertainty of amphibian species observed in the area, we integrated a DNA barcoding analysis into the project to improve the overall quality and accuracy of the species inventory. Based on morphology alone, 48 species were recognized in the field and voucher specimens of each were collected. We used tissue samples from specimens collected at our field site, material available from amphibians collected in other parts of Gabon and the Republic of Congo to initiate a DNA barcode library for west Central African amphibians. We then compared our sequences with material in GenBank for the genera recorded at the study site to assist in identifications. The resulting COI and 16S barcode library allowed us to update the number of species documented at the study site to 28, thereby providing a more accurate assessment of diversity and distributions. We caution that because sequence data maintained in GenBank are often poorly curated by the original submitters and cannot be amended by third-parties, these data have limited utility for identification purposes. Nevertheless, the use of DNA barcoding is likely to benefit biodiversity inventories and long-term monitoring, particularly for taxa that can be difficult to identify based on morphology alone; likewise, inventory and monitoring programs can contribute invaluable data to the DNA barcode library and

  11. Thermal limits of wild and laboratory strains of two African malaria vector species, Anopheles arabiensis and Anopheles funestus

    Directory of Open Access Journals (Sweden)

    Lyons Candice L

    2012-07-01

    Full Text Available Abstract Background Malaria affects large parts of the developing world and is responsible for almost 800,000 deaths annually. As climates change, concerns have arisen as to how this vector-borne disease will be impacted by changing rainfall patterns and warming temperatures. Despite the importance and controversy surrounding the impact of climate change on the potential spread of this disease, little information exists on the tolerances of several of the vector species themselves. Methods Using a ramping protocol (to assess critical thermal limits - CT and plunge protocol (to assess lethal temperature limits - LT information on the thermal tolerance of two of Africa’s important malaria vectors, Anopheles arabiensis and Anopheles funestus was collected. The effects of age, thermal acclimation treatment, sex and strain (laboratory versus wild adults were investigated for CT determinations for each species. The effects of age and sex for adults and life stage (larvae, pupae, adults were investigated for LT determinations. Results In both species, females are more tolerant to low and high temperatures than males; larvae and pupae have higher upper lethal limits than do adults. Thermal acclimation of adults has large effects in some instances but small effects in others. Younger adults tend to be more tolerant of low or high temperatures than older age groups. Long-standing laboratory colonies are sufficiently similar in thermal tolerance to field-collected animals to provide reasonable surrogates when making inferences about wild population responses. Differences between these two vectors in their thermal tolerances, especially in larvae and pupae, are plausibly a consequence of different habitat utilization. Conclusions Limited plasticity is characteristic of the adults of these vector species relative to others examined to date, suggesting limited scope for within-generation change in thermal tolerance. These findings and the greater tolerance

  12. Implementing telemetry on new species in remote areas: Recommendations from a large-scale satellite tracking study of African waterfowl

    Science.gov (United States)

    Cappelle, J.; Iverson, S.A.; Takekawa, John Y.; Newman, S.H.; Dodman, T.; Gaidet, N.

    2011-01-01

    We provide recommendations for implementing telemetry studies on waterfowl on the basis of our experience in a tracking study conducted in three countries of sub-Saharan Africa. The aim of the study was to document movements by duck species identified as priority candidates for the potential spread of avian influenza. Our study design included both captive and field test components on four wild duck species (Garganey, Comb Duck, White-faced Duck and Fulvous Duck). We used our location data to evaluate marking success and determine when signal loss occurred. The captive study of eight ducks marked with non-working transmitters in a zoo in Montpellier, France, prior to fieldwork showed no evidence of adverse effects, and the harness design appeared to work well. The field study in Malawi, Nigeria and Mali started in 2007 on 2 February, 6 February and 14 February, and ended on 22 November 2007 (288 d), 20 January 2010 (1 079 d), and 3 November 2008 (628 d), respectively. The field study indicated that 38 of 47 (81%) of the platform transmitter terminals (PTTs) kept transmitting after initial deployment, and the transmitters provided 15 576 locations. Signal loss during the field study was attributed to three main causes: PTT loss, PTT failure and mortality (natural, human-caused and PTT-related). The PTT signal quality varied by geographic region, and interference caused signal loss in the Mediterranean Sea region. We recommend careful attention at the beginning of the study to determine the optimum timing of transmitter deployment and the number of transmitters to be deployed per species. These sample sizes should be calculated by taking into account region-specific causes of signal loss to ensure research objectives are met. These recommendations should be useful for researchers undertaking a satellite tracking program, especially when working in remote areas of Africa where logistics are difficult or with poorly-known species. ?? NISC (Pty) Ltd.

  13. Morphological and biological study of Rhabdias spp. (Nematoda from african chameleons with description of a new species

    Directory of Open Access Journals (Sweden)

    Lhermitte-Vallarino N.

    2004-03-01

    Full Text Available Lung-dwelling females of Rhabdias (Rhabdiasidae, and possible migrating ceolomic young females were searched for in 46 chameleons, belonging to seven species. Rhabdias chamaeleonis, the single species identified to date in Africa, was found in Chamaeleo (Trioceros johnstoni and C. (T. hoehnelii, and redescribed ; the sizes of the buccal capsule and oesophagus were stable compared to the length of the female parasites, which varied from 6 mm to 22 mm in length. A second species, R. jarki n, sp., was identified from one C. (T. johnstoni ; it differed from R. chamaeleonis in the shape of anterior region, the longer and slender oesophagus (ratio bulb diameter-body diameter at that level about 1/5 instead of 1/2, the arrangement of the head papillae, the shape of the buccal capsule, and the anatomy of the genital apparatus : one of the ovaries (the anterior or posterior one according to the specimen had a band of small cells, among larger ovocytes of the synapsis zone, which were likely to generate the spermatozoa present in the oviducts, whereas these two elements were absent from R. chamaeleonis. The parasitic females of R. jarki thus appeared to be hermaphroditic, whereas those of R. chamaeleonis appeared to be parthenogenetic. The free living phase of these Rhabdias species was heterogonic. The infective larva of R. chamaeleonis was 360-590 µm long, unmotile and at third stage inside the maternal cuticle. The free-living male of R. jarki was described. The numerous infective larvae recovered from cultures of unidentified Rhabdias were all in maternal cuticle (one larva/female instead of two as in R. gemellipara from Calumma parsonii, from Madagascar and two kinds of larvae were identified, R. chamaeleonis and larvae 700-900 µm long provisionally identified to R. jarki. The behaviour of infective larvae and a few successful infections of insects suggest that, in the field, insect transport hosts are involved in transmission and in preventing

  14. Sensitivity of Above-Ground Biomass Estimates to Height-Diameter Modelling in Mixed-Species West African Woodlands.

    Directory of Open Access Journals (Sweden)

    Rubén Valbuena

    Full Text Available It has been suggested that above-ground biomass (AGB inventories should include tree height (H, in addition to diameter (D. As H is a difficult variable to measure, H-D models are commonly used to predict H. We tested a number of approaches for H-D modelling, including additive terms which increased the complexity of the model, and observed how differences in tree-level predictions of H propagated to plot-level AGB estimations. We were especially interested in detecting whether the choice of method can lead to bias. The compared approaches listed in the order of increasing complexity were: (B0 AGB estimations from D-only; (B1 involving also H obtained from a fixed-effects H-D model; (B2 involving also species; (B3 including also between-plot variability as random effects; and (B4 involving multilevel nested random effects for grouping plots in clusters. In light of the results, the modelling approach affected the AGB estimation significantly in some cases, although differences were negligible for some of the alternatives. The most important differences were found between including H or not in the AGB estimation. We observed that AGB predictions without H information were very sensitive to the environmental stress parameter (E, which can induce a critical bias. Regarding the H-D modelling, the most relevant effect was found when species was included as an additive term. We presented a two-step methodology, which succeeded in identifying the species for which the general H-D relation was relevant to modify. Based on the results, our final choice was the single-level mixed-effects model (B3, which accounts for the species but also for the plot random effects reflecting site-specific factors such as soil properties and degree of disturbance.

  15. Some South African Rubiaceae Tree Leaf Extracts Have Antimycobacterial Activity Against Pathogenic and Non-pathogenic Mycobacterium Species.

    Science.gov (United States)

    Aro, Abimbola O; Dzoyem, Jean P; Hlokwe, Tiny M; Madoroba, Evelyn; Eloff, Jacobus N; McGaw, Lyndy J

    2015-07-01

    Tuberculosis (TB) caused by Mycobacterium tuberculosis remains an ongoing threat to human health. Many plant species contain antimycobacterial compounds, which may serve as template molecules for new anti-TB drugs. The Rubiaceae family is the largest family of trees in southern Africa, and preliminary evidence revealed antimycobacterial activity in several species of the genus, motivating further studies. Leaf extracts of 15 tree species from the Rubiaceae family were screened for antimycobacterial activity against pathogenic M. tuberculosis and non-pathogenic Mycobacterium smegmatis, Mycobacterium aurum and Mycobacterium bovis BCG (Bacillus Calmette-Guérin) using a twofold serial microdilution assay. Cytotoxicity was determined using a tetrazolium-based colorimetric assay against C3A liver cells and Vero kidney cells. Minimum inhibitory concentration values as low as 0.04 mg/mL against M. smegmatis and M. tuberculosis were recorded. Activity against M. aurum was the best predictor of activity against pathogenic M. tuberculosis (correlation coefficient = 0.9). Bioautography indicated at least 40 different antimycobacterial compounds in the extracts. Cytotoxicity of the extracts varied, and Oxyanthus speciosus had the most promising selectivity index values. Copyright © 2015 John Wiley & Sons, Ltd.

  16. Transient Expression of Lumbrokinase (PI239 in Tobacco (Nicotiana tabacum Using a Geminivirus-Based Single Replicon System Dissolves Fibrin and Blood Clots

    Directory of Open Access Journals (Sweden)

    Alexia Dickey

    2017-01-01

    Full Text Available Lumbrokinases, a group of fibrinolytic enzymes extracted from earthworm, have been widely used to prevent and treat various cardiovascular diseases. They specifically target fibrin to effectively degrade thrombi without major side effects. Plant expression systems are becoming potential alternative expression platforms for producing pharmaceutical proteins. In this work, a lumbrokinase (PI239 was produced from a plant system. Both wild-type (WT and plant codon-optimized (OP PI239 gene sequences were synthesized and cloned into a geminivirus-based single-vector DNA replicon system. Both vectors were independently expressed in tobacco (Nicotiana tabacum leaves transiently by agroinfiltration. Overexpressed PI239 resulted in sudden tissue necrosis 3 days after infiltration. Remaining proteins were purified through His-tag affinity chromatography and analyzed with SDS-PAGE and Western blot methods. Purified PI239 successfully degraded artificial fibrin with relative activity of 13,400 U/mg when compared with commercial lumbrokinase product. In vitro tests demonstrated that plant-derived PI239 dissolved human blood clots and that the plant expression system is capable of producing functional PI239.

  17. Tomato SlSnRK1 protein interacts with and phosphorylates βC1, a pathogenesis protein encoded by a geminivirus β-satellite.

    Science.gov (United States)

    Shen, Qingtang; Liu, Zhou; Song, Fengming; Xie, Qi; Hanley-Bowdoin, Linda; Zhou, Xueping

    2011-11-01

    The βC1 protein of tomato yellow leaf curl China β-satellite functions as a pathogenicity determinant. To better understand the molecular basis of βC1 in pathogenicity, a yeast two-hybrid screen of a tomato (Solanum lycopersicum) cDNA library was carried out using βC1 as bait. βC1 interacted with a tomato SUCROSE-NONFERMENTING1-related kinase designated as SlSnRK1. Their interaction was confirmed using a bimolecular fluorescence complementation assay in Nicotiana benthamiana cells. Plants overexpressing SnRK1 were delayed for symptom appearance and contained lower levels of viral and satellite DNA, while plants silenced for SnRK1 expression developed symptoms earlier and accumulated higher levels of viral DNA. In vitro kinase assays showed that βC1 is phosphorylated by SlSnRK1 mainly on serine at position 33 and threonine at position 78. Plants infected with βC1 mutants containing phosphorylation-mimic aspartate residues in place of serine-33 and/or threonine-78 displayed delayed and attenuated symptoms and accumulated lower levels of viral DNA, while plants infected with phosphorylation-negative alanine mutants contained higher levels of viral DNA. These results suggested that the SlSnRK1 protein attenuates geminivirus infection by interacting with and phosphorylating the βC1 protein.

  18. CLCuMuB βC1 Subverts Ubiquitination by Interacting with NbSKP1s to Enhance Geminivirus Infection in Nicotiana benthamiana.

    Directory of Open Access Journals (Sweden)

    Qi Jia

    2016-06-01

    Full Text Available Viruses interfere with and usurp host machinery and circumvent defense responses to create a suitable cellular environment for successful infection. This is usually achieved through interactions between viral proteins and host factors. Geminiviruses are a group of plant-infecting DNA viruses, of which some contain a betasatellite, known as DNAβ. Here, we report that Cotton leaf curl Multan virus (CLCuMuV uses its sole satellite-encoded protein βC1 to regulate the plant ubiquitination pathway for effective infection. We found that CLCuMu betasatellite (CLCuMuB βC1 interacts with NbSKP1, and interrupts the interaction of NbSKP1s with NbCUL1. Silencing of either NbSKP1s or NbCUL1 enhances the accumulation of CLCuMuV genomic DNA and results in severe disease symptoms in plants. βC1 impairs the integrity of SCFCOI1 and the stabilization of GAI, a substrate of the SCFSYL1 to hinder responses to jasmonates (JA and gibberellins (GA. Moreover, JA treatment reduces viral accumulation and symptoms. These results suggest that CLCuMuB βC1 inhibits the ubiquitination function of SCF E3 ligases through interacting with NbSKP1s to enhance CLCuMuV infection and symptom induction in plants.

  19. Evaluating the capability of Landsat 8 OLI and SPOT 6 for discriminating invasive alien species in the African Savanna landscape

    Science.gov (United States)

    Kganyago, Mahlatse; Odindi, John; Adjorlolo, Clement; Mhangara, Paidamoyo

    2018-05-01

    Globally, there is paucity of accurate information on the spatial distribution and patch sizes of Invasive Alien Plants (IAPs) species. Such information is needed to aid optimisation of control mechanisms to prevent further spread of IAPs and minimize their impacts. Recent studies have shown the capability of very high spatial (<1 m) and spectral resolution (<10 nm) data for discriminating vegetation species. However, very high spatial resolution may introduce significant intra-species spectral variability and result in reduced mapping accuracy, while higher spectral resolution data are commonly limited to smaller areas, are costly and computationally expensive. Alternatively, medium and high spatial resolution data are available at low or no cost and have limitedly been evaluated for their potential in determining invasion patterns relevant for invasion ecology and aiding effective IAPs management. In this study medium and high resolution datasets from Landsat Operational Land Imager (OLI) and SPOT 6 sensors respectively, were evaluated for mapping the distribution and patch sizes of IAP, Parthenium hysterophorus in the savannah landscapes of KwaZulu-Natal, South Africa. Support Vector Machines (SVM) classifier was used for classification of both datasets. Results indicated that SPOT 6 had a higher overall accuracy (86%) than OLI (83%) in mapping P. hysterophorus. The study found larger distributions and patch sizes in OLI than in SPOT 6 as a result of possible P. hysterophorus expansion due to temporal differences between images and coarser pixels were insufficient to delineate gaps inside larger patches. On the other hand, SPOT 6 showed better capabilities of delineating gaps and boundaries of patches, hence had better estimates of distribution and patch sizes. Overall, the study showed that OLI may be suitable for mapping well-established patches for the purpose of large scale monitoring, while SPOT 6 can be used for mapping small patches and prioritising them

  20. Evaluation of the inhibition of carbohydrate hydrolysing enzymes, antioxidant activity and polyphenolic content of extracts of ten African Ficus species (Moraceae) used traditionally to treat diabetes.

    Science.gov (United States)

    Olaokun, Oyinlola O; McGaw, Lyndy J; Eloff, Jacobus N; Naidoo, Vinny

    2013-05-04

    Some Ficus species have been used in traditional African medicine in the treatment of diabetes. The antidiabetic potential of certain species has been confirmed in vivo but the mechanism of activity remains uncertain. The aim of this study was to determine the activity and to investigate the mechanism of antidiabetic activity of ten selected Ficus species through inhibition of α-amylase and α-glucosidase activity, and the possible relationship between these activities, the total polyphenolic content and the antioxidant activity. Dried acetone leaf extracts were reconstituted with appropriate solvents and used to determine total polyphenolic content antioxidant activity, α-amylase and α-glucosidase inhibitory activity. The crude acetone extract of F. lutea had the highest polyphenolic content (56.85 ± 1.82 mg GAE/g of dry material) and the strongest antioxidant activity with a TEAC value of 4.80 ± 0.90. The antioxidant activity of the acetone extracts of the Ficus species may not be ascribed to total polyphenolic content alone. The crude extract at a concentration of 0.5 mg/ml of F. lutea (64.3 ± 3.6%) had the best α-glucosidase (sucrase) inhibitory activity. The EC50 of F. lutea (290 ± 111 μg/ml) was not significantly different from that of F. sycomorus (217 ± 69 μg/ml). The α-amylase inhibitory activity of F. lutea (95.4 ± 1.2%) at a concentration of 1 mg/ml was the highest among the Ficus species screened. The EC50 for F. lutea (9.42 ± 2.01 μ g/ml), though the highest, was not significantly different (p < 0.05) from that of F. craterostoma and F. natalensis. It was apparent that the crude acetone extract of F. lutea is a partially non-competitive inhibitor of α-amylase and α-glucosidase. Based on correlation coefficients polyphenolics may be responsible for α-glucosidase activity but probably not for α-amylase activity. Antidiabetic activity potential via inhibition of α-amylase and α-glucosidase was

  1. Serosurvey for Selected Viral Pathogens among Sympatric Species of the African Large Predator Guild in Northern Botswana.

    Science.gov (United States)

    Chaber, Anne-Lise; Cozzi, Gabriele; Broekhuis, Femke; Hartley, Robyn; W McNutt, John

    2017-01-01

    The recent increase in the creation of transboundary protected areas and wildlife corridors between them lends importance to information on pathogen prevalence and transmission among wildlife species that will become connected. One such initiative is the Kavango Zambezi Transfrontier Conservation Area of which Botswana's Okavango Delta constitutes a major contribution for wildlife and ecosystems. Between 2008 and 2011, we collected serum samples from 14 lions ( Panthera leo ), four leopards ( Panthera pardus ), 19 spotted hyenas ( Crocuta crocuta ), and six cheetahs ( Acinonyx jubatus ) in the Okavango. Samples were tested for antibodies against canine distemper virus (CDV), feline panleukopenia virus, enteric coronavirus, feline calicivirus, feline herpesvirus (FHV-1), and feline immunodeficiency virus (FIV). Evidence of exposure to all of these pathogens was found, to varying degrees, in at least one of the species sampled. High antibody prevalence (>90%) was only found to FHV-1 and FIV in lions. Only hyenas (26%, 5/19) were positive for CDV antibody. Except for one case, all individuals displayed physical conditions consistent with normal health for ≥12 mo following sampling. Our results emphasize the need for a comprehensive, multispecies approach to disease monitoring and the development of coordinated management strategies for subpopulations likely to be connected in transboundary initiatives.

  2. Genetic Diversity and Population Structure of a Threatened African Tree Species, Milicia excelsa, Using Nuclear Micro satellites DNA Markers

    International Nuclear Information System (INIS)

    Ouinsavi, Ch.; Sokpon, N.; Ouinsavi, Ch.; Khasa, D.P.

    2009-01-01

    To accurately estimate the genetic diversity and population structure for improved conservation planning of Milicia excelsa tree, 212 individuals from twelve population samples covering the species' range in Benin were surveyed at seven specific micro satellite DNA loci. All loci were variable, with the mean number of alleles per locus ranging from 5.86 to 7.69. Considerable genetic variability was detected for all populations at the seven loci (AR=4.60; HE=0.811). Moderate but statistically significant genetic differentiation was found among populations considering both FST (0.112) and RST (0.342). All of the populations showed heterozygosity deficits in test of Hardy-Weinberg Equilibrium and significantly positive FIS values due to inbreeding occurring in the species. Pairwise FST values were positively and significantly correlated with geographical distances (r=0.432; P=.007, Mantel's test) indicating that populations are differentiated by isolation by distance. Bayesian analysis of population structure showed division of the genetic variation into four clusters revealing the existence of heterogeneity in population genetic structure. Altogether, these results indicate that genetic variation in Milicia excelsa is geographically structured. Information gained from this study also emphasized the need for in situ conservation of the relict populations and establishment of gene flow corridors through agroforestry systems for interconnecting these remnant populations.

  3. Antibiogram, Adhesive Characteristics, and Incidence of Class 1 Integron in Aeromonas Species Isolated from Two South African Rivers

    Directory of Open Access Journals (Sweden)

    Isoken H. Igbinosa

    2013-01-01

    Full Text Available Aeromonas species are well distributed in freshwater environments, and their natural susceptibility to antimicrobials renders them interesting candidates for the survey of antimicrobial resistance in freshwater milieu. Water samples were collected from Kat and Tyume rivers in the Eastern Cape province of South Africa, and a total of 45 isolates identified as Aeromonas species were recovered from the two rivers. All Aeromonas isolates were resistant to oxacillin, penicillin, clindamycin, cephalothin, vancomycin, and rifamycin, while appreciable susceptibilities (89.3 : 94.1%, 82.1 : 94.1%, 85.7 : 88.2%, and 92.9 : 88.2% were observed against ciprofloxacin, chloramphenicol, nitrofurantoin, and gentamicin from Kat and Tyume rivers, respectively. Multiple antibiotic resistance (MAR indices ranged from 0.016 to 0.044 for the two rivers. Class 1 integron was detected in about 20% of the isolates, and all the isolates except one showed ability to produce biofilm in vitro as weak producers (53.33%, moderate producers (15.56%, and strong producers (28.9%. This investigation provides a baseline data on antibiotic resistance as well as the adhesive characteristics of Aeromonas isolates from Tyume and Kat rivers in the Eastern Cape province of South Africa.

  4. Biting behaviour of African malaria vectors: 1. where do the main vector species bite on the human body?

    Science.gov (United States)

    Braack, Leo; Hunt, Richard; Koekemoer, Lizette L; Gericke, Anton; Munhenga, Givemore; Haddow, Andrew D; Becker, Piet; Okia, Michael; Kimera, Isaac; Coetzee, Maureen

    2015-02-04

    Malaria control in Africa relies heavily on indoor vector management, primarily indoor residual spraying and insecticide treated bed nets. Little is known about outdoor biting behaviour or even the dynamics of indoor biting and infection risk of sleeping household occupants. In this paper we explore the preferred biting sites on the human body and some of the ramifications regarding infection risk and exposure management. We undertook whole-night human landing catches of Anopheles arabiensis in South Africa and Anopheles gambiae s.s. and Anopheles funestus in Uganda, for seated persons wearing short sleeve shirts, short pants, and bare legs, ankles and feet. Catches were kept separate for different body regions and capture sessions. All An. gambiae s.l. and An. funestus group individuals were identified to species level by PCR. Three of the main vectors of malaria in Africa (An. arabiensis, An. gambiae s.s. and An. funestus) all have a preference for feeding close to ground level, which is manifested as a strong propensity (77.3% - 100%) for biting on lower leg, ankles and feet of people seated either indoors or outdoors, but somewhat randomly along the lower edge of the body in contact with the surface when lying down. If the lower extremities of the legs (below mid-calf level) of seated people are protected and therefore exclude access to this body region, vector mosquitoes do not move higher up the body to feed at alternate body sites, instead resulting in a high (58.5% - 68.8%) reduction in biting intensity by these three species. Protecting the lower limbs of people outdoors at night can achieve a major reduction in biting intensity by malaria vector mosquitoes. Persons sleeping at floor level bear a disproportionate risk of being bitten at night because this is the preferred height for feeding by the primary vector species. Therefore it is critical to protect children sleeping at floor level (bednets; repellent-impregnated blankets or sheets, etc

  5. Assessing diet quality of African ungulates from faecal analyses: the effect of forage quality, intake and herbivore species

    Directory of Open Access Journals (Sweden)

    J.M. Wrench

    1997-08-01

    Full Text Available Faecal phosphorous and nitrogen can be used as indicators of the nutritive content of the veld. Dietary P concentrations can be predicted with reasonable accuracy from faecal P concentrations in faeces of caged impala rams using a simple linear regression model, Y = 0.393X (r2 = 0.97. This regression holds whether impala are grazing or browsing as well as for high and low levels of intake. The regression equation used in the prediction of dietary P in zebra, blue wildebeest and cattle, did not differ significantly from this simple regression and a combined regression equation could be formulated. A faecal P concentration of less than 2 g P/kg OM would appear to indicate a P deficiency in most species. The prediction of dietary N is influenced by the intake of phenolic compounds and different regression equations exist for grazers and browsers. For prediction of dietary N concentrations, both the concentration of N and P in the faeces should be taken into account. This multiple regression equation is applicable for grazing impala at all levels of intake. For impala utilising browse, a regression model with faecal Acid Detergent Insoluble Nitrogen (ADIN and Acid Detergent Lignin (ADL should be used to predict dietary N concentration. For grazers, a faecal N concentration of less than 14 g/kg DM would indicate a deficiency. Dietary digestibility can be predicted accurately in some species using faecal N, P and ADL concentrations. However, more work needs to be done to quantify their effects.

  6. Estimating environmental preferences of South African pelagic fish species using catch size- and remote sensing data [review article

    Science.gov (United States)

    Agenbag, J. J.; Richardson, A. J.; Demarcq, H.; Fréon, P.; Weeks, S.; Shillington, F. A.

    2003-10-01

    We have studied the relationship between the variations in density of South African anchovy ( Engraulisicapensis), sardine ( Sardinopssagax) and round herring ( Etrumeuswhiteheadi) from commercial catch records (1987-1997) and a suite of variables describing the environment. The indicator of density (local fish abundance) used was Catch-per-set, obtained from the more than 130 000 catches made during the 11-year study period. The set of environmental parameters included: temporal ( Year, Month, time of day or Hour), spatial ( Latitude, Longitude and water Depth), lunar ( Moonphase and Moonelevation), and thermal conditions of the environment (sea surface temperature together with indices of thermal frontal intensity and temporal change). Boatlength was used to account for fishing gear effects. Previous investigations of this nature have tended to use simple bivariate correlation approaches, which suffer from the problem of covariance between the predictive variable and other environmental- or fisheries related variables not included in the analysis. We have, therefore, adopted a multivariate modelling approach, which identifies relationships between Catch-per-set and each environmental variable, accounting for covariation amongst predictors. Model building consisted of first constructing generalised additive models (GAM) as an exploratory tool to identify the shapes of the relationships, followed by parameterising these relationships using general linear models (GLM) to provide a robust predictive tool. Using this modelling approach, the suite of environmental variables explained 19.6% of the variation in Catch-per-set of anchovy, 33.9% of sardine, and 54.3% of round herring in the final GLM models. Temporal variables ( Year, Month, Hour), accounted for the major part of the variability in Catch-per-set but variables derived from SST and the lunar cycle provide insight into the effects of environmental factors on fish behaviour. For instance, it appears that

  7. Four plant defensins from an indigenous South African Brassicaceae species display divergent activities against two test pathogens despite high sequence similarity in the encoding genes

    Directory of Open Access Journals (Sweden)

    de Beer Abré

    2011-10-01

    Full Text Available Abstract Background Plant defensins are an important component of the innate defence system of plants where they form protective antimicrobial barriers between tissue types of plant organs as well as around seeds. These peptides also have other activities that are important for agricultural applications as well as the medical sector. Amongst the numerous plant peptides isolated from a variety of plant species, a significant number of promising defensins have been isolated from Brassicaceae species. Here we report on the isolation and characterization of four defensins from Heliophila coronopifolia, a native South African Brassicaceae species. Results Four defensin genes (Hc-AFP1-4 were isolated with a homology based PCR strategy. Analysis of the deduced amino acid sequences showed that the peptides were 72% similar and grouped closest to defensins isolated from other Brassicaceae species. The Hc-AFP1 and 3 peptides shared high homology (94% and formed a unique grouping in the Brassicaceae defensins, whereas Hc-AFP2 and 4 formed a second homology grouping with defensins from Arabidopsis and Raphanus. Homology modelling showed that the few amino acids that differed between the four peptides had an effect on the surface properties of the defensins, specifically in the alpha-helix and the loop connecting the second and third beta-strands. These areas are implicated in determining differential activities of defensins. Comparing the activities after recombinant production of the peptides, Hc-AFP2 and 4 had IC50 values of 5-20 μg ml-1 against two test pathogens, whereas Hc-AFP1 and 3 were less active. The activity against Botrytis cinerea was associated with membrane permeabilization, hyper-branching, biomass reduction and even lytic activity. In contrast, only Hc-AFP2 and 4 caused membrane permeabilization and severe hyper-branching against the wilting pathogen Fusarium solani, while Hc-AFP1 and 3 had a mild morphogenetic effect on the fungus

  8. Characterization of bradykinin-related peptides generated in the plasma of six sarcopterygian species (African lungfish, amphiuma, coachwhip, bullsnake, gila monster, and Gray's monitor).

    Science.gov (United States)

    Li, Z; Secor, S M; Lance, V A; Masini, M A; Vallarino, M; Conlon, J M

    1998-10-01

    Incubation of heat-denatured plasma from six species occupying different evolutionary positions within the Sarcopterygian lineage [the dipnoan, Protopterus annectens (African lungfish); the urodele, Amphiuma tridactylum (three-toed amphiuma); the colubrid snakes, Pituophis melanoleucus sayi (bullsnake) and Masticophis flagellum (coachwhip); and the lizards Heloderma suspectum (Gila monster) and Varanus Grayi (Gray's monitor)] with trypsin generated bradykinin-related peptides that were detected by radioimmunoassay using an antiserum raised against mammalian bradykinin (BK). The peptides were purified by HPLC and their primary structures were established as lungfish [Tyr1,Gly2,Ala7,Pro8]BK, amphiuma [Phe1,Ile2, Leu5]BK, bullsnake and coachwhip [Val1,Thr6]BK, Gila monster [Leu2, Thr6]BK, and Gray's monitor [Thr6]BK. Monitor BK is identical to the peptide generated in turtle and alligator plasma and coachwhip/bullsnake BK shows one amino acid substitution (Ala1 --> Val) compared with the peptide generated in the plasma of the python. The data provide further evidence for the widespread occurrence of a kallikrein-kininogen system in nonmammalian vertebrates but indicate that the primary structure of BK has been poorly conserved during evolution. Copyright 1998 Academic Press.

  9. Some southern African plant species used to treat helminth infections in ethnoveterinary medicine have excellent antifungal activities

    Directory of Open Access Journals (Sweden)

    Adamu Mathew

    2012-11-01

    Full Text Available Abstract Background Diseases caused by microorganisms and parasites remain a major challenge globally and particularly in sub-Saharan Africa to man and livestock. Resistance to available antimicrobials and the high cost or unavailability of antimicrobials complicates matters. Many rural people use plants to treat these infections. Because some anthelmintics e.g. benzimidazoles also have good antifungal activity we examined the antifungal activity of extracts of 13 plant species used in southern Africa to treat gastrointestinal helminth infections in livestock and in man. Methods Antifungal activity of acetone leaf extracts was determined by serial microdilution with tetrazolium violet as growth indicator against Aspergillus fumigatus, Cryptococcus neoformans and Candida albicans. These pathogens play an important role in opportunistic infections of immune compromised patients. Cytotoxicity was determined by MTT cellular assay. Therapeutic indices were calculated and selectivity for different pathogens determined. We proposed a method to calculate the relation between microbicidal and microbistatic activities. Total activities for different plant species were calculated. Results On the whole, all 13 extracts had good antifungal activities with MIC values as low as 0.02 mg/mL for extracts of Clausena anisata against Aspergillus fumigatus and 0.04 mg/mL for extracts of Zanthoxylum capense, Clerodendrum glabrum, and Milletia grandis, against A. fumigatus. Clausena anisata extracts had the lowest cytotoxicity (LC50 of 0.17 mg/mL, a reasonable therapeutic index (2.65 against A. fumigatus. It also had selective activity against A. fumigatus, an overall fungicidal activity of 98% and a total activity of 3395 mL/g against A. fumigatus. This means that 1 g of acetone leaf extract can be diluted to 3.4 litres and it would still inhibit the growth. Clerodendrum glabrum, Zanthoxylum capense and Milletia grandis extracts also yielded promising results

  10. Transcriptomics of the interaction between the monopartite phloem-limited geminivirus tomato yellow leaf curl Sardinia virus and Solanum lycopersicum highlights a role for plant hormones, autophagy and plant immune system fine tuning during infection.

    Directory of Open Access Journals (Sweden)

    Laura Miozzi

    Full Text Available Tomato yellow leaf curl Sardinia virus (TYLCSV, a DNA virus belonging to the genus Begomovirus, causes severe losses in tomato crops. It infects only a limited number of cells in the vascular tissues, making difficult to detect changes in host gene expression linked to its presence. Here we present the first microarray study of transcriptional changes induced by the phloem-limited geminivirus TYLCSV infecting tomato, its natural host. The analysis was performed on the midrib of mature leaves, a material naturally enriched in vascular tissues. A total of 2206 genes were up-regulated and 1398 were down-regulated in infected plants, with an overrepresentation of genes involved in hormone metabolism and responses, nucleic acid metabolism, regulation of transcription, ubiquitin-proteasome pathway and autophagy among those up-regulated, and in primary and secondary metabolism, phosphorylation, transcription and methylation-dependent chromatin silencing among those down-regulated. Our analysis showed a series of responses, such as the induction of GA- and ABA-responsive genes, the activation of the autophagic process and the fine tuning of the plant immune system, observed only in TYLCSV-tomato compatible interaction so far. On the other hand, comparisons with transcriptional changes observed in other geminivirus-plant interactions highlighted common host responses consisting in the deregulation of biotic stress responsive genes, key enzymes in the ethylene biosynthesis and methylation cycle, components of the ubiquitin proteasome system and DNA polymerases II. The involvement of conserved miRNAs and of solanaceous- and tomato-specific miRNAs in geminivirus infection, investigated by integrating differential gene expression data with miRNA targeting data, is discussed.

  11. PCR-based identification of eight lactobacillus species and 18 hr-HPV genotypes in fixed cervical samples of south african women at risk of HIV and BV

    NARCIS (Netherlands)

    Dols, J.A.M.; Reid, G.; Kort, R.; Schuren, F.H.J.; Tempelman, H.; Bontekoe, T.R.; Korporaal, H.; Veer, E.M. van der; Smit, P.W.; Boon, M.E.

    2012-01-01

    Vaginal lactobacilli assessed by PCR-based microarray and PCR-based genotyping of HPV in South African women at risk for HIV and BV. Vaginal lactobacilli can be defined by microarray techniques in fixed cervical samples of South African women. Cervical brush samples suspended in the coagulant

  12. The RXL motif of the African cassava mosaic virus Rep protein is necessary for rereplication of yeast DNA and viral infection in plants

    Energy Technology Data Exchange (ETDEWEB)

    Hipp, Katharina; Rau, Peter; Schäfer, Benjamin [Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany); Gronenborn, Bruno [Institut des Sciences du Végétal, CNRS, 91198 Gif-sur-Yvette (France); Jeske, Holger, E-mail: holger.jeske@bio.uni-stuttgart.de [Institut für Biomaterialien und biomolekulare Systeme, Abteilung für Molekularbiologie und Virologie der Pflanzen, Universität Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart (Germany)

    2014-08-15

    Geminiviruses, single-stranded DNA plant viruses, encode a replication-initiator protein (Rep) that is indispensable for virus replication. A potential cyclin interaction motif (RXL) in the sequence of African cassava mosaic virus Rep may be an alternative link to cell cycle controls to the known interaction with plant homologs of retinoblastoma protein (pRBR). Mutation of this motif abrogated rereplication in fission yeast induced by expression of wildtype Rep suggesting that Rep interacts via its RXL motif with one or several yeast proteins. The RXL motif is essential for viral infection of Nicotiana benthamiana plants, since mutation of this motif in infectious clones prevented any symptomatic infection. The cell-cycle link (Clink) protein of a nanovirus (faba bean necrotic yellows virus) was investigated that activates the cell cycle by binding via its LXCXE motif to pRBR. Expression of wildtype Clink and a Clink mutant deficient in pRBR-binding did not trigger rereplication in fission yeast. - Highlights: • A potential cyclin interaction motif is conserved in geminivirus Rep proteins. • In ACMV Rep, this motif (RXL) is essential for rereplication of fission yeast DNA. • Mutating RXL abrogated viral infection completely in Nicotiana benthamiana. • Expression of a nanovirus Clink protein in yeast did not induce rereplication. • Plant viruses may have evolved multiple routes to exploit host DNA synthesis.

  13. Complex recombination patterns arising during geminivirus coinfections preserve and demarcate biologically important intra-genome interaction networks.

    OpenAIRE

    Darren P Martin; Pierre Lefeuvre; Arvind Varsani; Murielle Hoareau; Jean-Yves Semegni; Betty Dijoux; Claire Vincent; Bernard Reynaud; Jean-Michel Lett

    2011-01-01

    Genetic recombination is an important process during the evolution of many virus species and occurs particularly frequently amongst begomoviruses in the single stranded DNA virus family, Geminiviridae. As in many other recombining viruses it is apparent that non-random recombination breakpoint distributions observable within begomovirus genomes sampled from nature are the product of variations both in basal recombination rates across genomes and in the over-all viability of different recombin...

  14. A geminivirus-based guide RNA delivery system for CRISPR/Cas9 mediated plant genome editing

    OpenAIRE

    Yin, Kangquan; Han, Ting; Liu, Guang; Chen, Tianyuan; Wang, Ying; Yu, Alice Yunzi L.; Liu, Yule

    2015-01-01

    CRISPR/Cas has emerged as potent genome editing technology and has successfully been applied in many organisms, including several plant species. However, delivery of genome editing reagents remains a challenge in plants. Here, we report a virus-based guide RNA (gRNA) delivery system for CRISPR/Cas9 mediated plant genome editing (VIGE) that can be used to precisely target genome locations and cause mutations. VIGE is performed by using a modified Cabbage Leaf Curl virus (CaLCuV) vector to expr...

  15. African Literature

    OpenAIRE

    Recek, Denis

    2011-01-01

    The topic of this diploma is the formation and shaping of African literature. The first chapter is about the beginning of African literature. It describes oral literature and its transmission into written literature. Written African literature had great problems in becoming a part of world literature because of its diversity of languages and dialects. Christianity and Islam are mentioned as two religions which had a great impact on African literature. Colonialism is broadly described as an es...

  16. The study of trypanosome species circulating in domestic animals in two human African trypanosomiasis foci of Côte d'Ivoire identifies pigs and cattle as potential reservoirs of Trypanosoma brucei gambiense

    Science.gov (United States)

    N’Djetchi, Martial Kassi; Ilboudo, Hamidou; Koffi, Mathurin; Kaboré, Jacques; Kaboré, Justin Windingoudi; Kaba, Dramane; Courtin, Fabrice; Coulibaly, Bamoro; Fauret, Pierre; Kouakou, Lingué; Ravel, Sophie; Deborggraeve, Stijn; Solano, Philippe; De Meeûs, Thierry; Bucheton, Bruno

    2017-01-01

    Background Important control efforts have led to a significant reduction of the prevalence of human African trypanosomiasis (HAT) in Côte d’Ivoire, but the disease is still present in several foci. The existence of an animal reservoir of Trypanosoma brucei gambiense may explain disease persistence in these foci where animal breeding is an important source of income but where the prevalence of animal African trypanosomiasis (AAT) is unknown. The aim of this study was to identify the trypanosome species circulating in domestic animals in both Bonon and Sinfra HAT endemic foci. Methodology/Principal findings 552 domestic animals (goats, pigs, cattle and sheep) were included. Blood samples were tested for trypanosomes by microscopic observation, species-specific PCR for T. brucei sl, T. congolense, T. vivax and subspecies-specific PCR for T. b. gambiense and T. b. gambiense immune trypanolysis (TL). Infection rates varied significantly between animal species and were by far the highest in pigs (30%). T. brucei s.l was the most prevalent trypanosome species (13.7%) followed by T. congolense. No T. b. gambiense was identified by PCR while high TL positivity rates were observed using T. b. gambiense specific variants (up to 27.6% for pigs in the Bonon focus). Conclusion This study shows that domestic animals are highly infected by trypanosomes in the studied foci. This was particularly true for pigs, possibly due to a higher exposure of these animals to tsetse flies. Whereas T. brucei s.l. was the most prevalent species, discordant results were obtained between PCR and TL regarding T. b. gambiense identification. It is therefore crucial to develop better tools to study the epidemiological role of potential animal reservoir for T. b. gambiense. Our study illustrates the importance of “one health” approaches to reach HAT elimination and contribute to AAT control in the studied foci. PMID:29045405

  17. The study of trypanosome species circulating in domestic animals in two human African trypanosomiasis foci of Côte d'Ivoire identifies pigs and cattle as potential reservoirs of Trypanosoma brucei gambiense.

    Science.gov (United States)

    N'Djetchi, Martial Kassi; Ilboudo, Hamidou; Koffi, Mathurin; Kaboré, Jacques; Kaboré, Justin Windingoudi; Kaba, Dramane; Courtin, Fabrice; Coulibaly, Bamoro; Fauret, Pierre; Kouakou, Lingué; Ravel, Sophie; Deborggraeve, Stijn; Solano, Philippe; De Meeûs, Thierry; Bucheton, Bruno; Jamonneau, Vincent

    2017-10-01

    Important control efforts have led to a significant reduction of the prevalence of human African trypanosomiasis (HAT) in Côte d'Ivoire, but the disease is still present in several foci. The existence of an animal reservoir of Trypanosoma brucei gambiense may explain disease persistence in these foci where animal breeding is an important source of income but where the prevalence of animal African trypanosomiasis (AAT) is unknown. The aim of this study was to identify the trypanosome species circulating in domestic animals in both Bonon and Sinfra HAT endemic foci. 552 domestic animals (goats, pigs, cattle and sheep) were included. Blood samples were tested for trypanosomes by microscopic observation, species-specific PCR for T. brucei sl, T. congolense, T. vivax and subspecies-specific PCR for T. b. gambiense and T. b. gambiense immune trypanolysis (TL). Infection rates varied significantly between animal species and were by far the highest in pigs (30%). T. brucei s.l was the most prevalent trypanosome species (13.7%) followed by T. congolense. No T. b. gambiense was identified by PCR while high TL positivity rates were observed using T. b. gambiense specific variants (up to 27.6% for pigs in the Bonon focus). This study shows that domestic animals are highly infected by trypanosomes in the studied foci. This was particularly true for pigs, possibly due to a higher exposure of these animals to tsetse flies. Whereas T. brucei s.l. was the most prevalent species, discordant results were obtained between PCR and TL regarding T. b. gambiense identification. It is therefore crucial to develop better tools to study the epidemiological role of potential animal reservoir for T. b. gambiense. Our study illustrates the importance of "one health" approaches to reach HAT elimination and contribute to AAT control in the studied foci.

  18. African Anthropologist

    African Journals Online (AJOL)

    African Anthropology is the journal of the Pan African Anthropological Association (PAAA). It provides a forum for African and Africanist anthropologists to publish research reports, articles, book reviews, news items and other useful information. It aims at stimulating the debate of ideas and the development of methods and ...

  19. Complex recombination patterns arising during geminivirus coinfections preserve and demarcate biologically important intra-genome interaction networks.

    Directory of Open Access Journals (Sweden)

    Darren P Martin

    2011-09-01

    Full Text Available Genetic recombination is an important process during the evolution of many virus species and occurs particularly frequently amongst begomoviruses in the single stranded DNA virus family, Geminiviridae. As in many other recombining viruses it is apparent that non-random recombination breakpoint distributions observable within begomovirus genomes sampled from nature are the product of variations both in basal recombination rates across genomes and in the over-all viability of different recombinant genomes. Whereas factors influencing basal recombination rates might include local degrees of sequence similarity between recombining genomes, nucleic acid secondary structures and genomic sensitivity to nuclease attack or breakage, the viability of recombinant genomes could be influenced by the degree to which their co-evolved protein-protein and protein-nucleotide and nucleotide-nucleotide interactions are disreputable by recombination. Here we investigate patterns of recombination that occur over 120 day long experimental infections of tomato plants with the begomoviruses Tomato yellow leaf curl virus and Tomato leaf curl Comoros virus. We show that patterns of sequence exchange between these viruses can be extraordinarily complex and present clear evidence that factors such as local degrees of sequence similarity but not genomic secondary structure strongly influence where recombination breakpoints occur. It is also apparent from our experiment that over-all patterns of recombination are strongly influenced by selection against individual recombinants displaying disrupted intra-genomic interactions such as those required for proper protein and nucleic acid folding. Crucially, we find that selection favoring the preservation of co-evolved longer-range protein-protein and protein DNA interactions is so strong that its imprint can even be used to identify the exact sequence tracts involved in these interactions.

  20. Complex recombination patterns arising during geminivirus coinfections preserve and demarcate biologically important intra-genome interaction networks.

    Science.gov (United States)

    Martin, Darren P; Lefeuvre, Pierre; Varsani, Arvind; Hoareau, Murielle; Semegni, Jean-Yves; Dijoux, Betty; Vincent, Claire; Reynaud, Bernard; Lett, Jean-Michel

    2011-09-01

    Genetic recombination is an important process during the evolution of many virus species and occurs particularly frequently amongst begomoviruses in the single stranded DNA virus family, Geminiviridae. As in many other recombining viruses it is apparent that non-random recombination breakpoint distributions observable within begomovirus genomes sampled from nature are the product of variations both in basal recombination rates across genomes and in the over-all viability of different recombinant genomes. Whereas factors influencing basal recombination rates might include local degrees of sequence similarity between recombining genomes, nucleic acid secondary structures and genomic sensitivity to nuclease attack or breakage, the viability of recombinant genomes could be influenced by the degree to which their co-evolved protein-protein and protein-nucleotide and nucleotide-nucleotide interactions are disreputable by recombination. Here we investigate patterns of recombination that occur over 120 day long experimental infections of tomato plants with the begomoviruses Tomato yellow leaf curl virus and Tomato leaf curl Comoros virus. We show that patterns of sequence exchange between these viruses can be extraordinarily complex and present clear evidence that factors such as local degrees of sequence similarity but not genomic secondary structure strongly influence where recombination breakpoints occur. It is also apparent from our experiment that over-all patterns of recombination are strongly influenced by selection against individual recombinants displaying disrupted intra-genomic interactions such as those required for proper protein and nucleic acid folding. Crucially, we find that selection favoring the preservation of co-evolved longer-range protein-protein and protein DNA interactions is so strong that its imprint can even be used to identify the exact sequence tracts involved in these interactions.

  1. African Journals Online: African Studies

    African Journals Online (AJOL)

    Items 51 - 56 of 56 ... Research Review of the Institute of African Studies. Please note: As of 2013 the Research Review of the Institute of African Studies is now publishing under the title Contemporary Journal of African Studies. You can view the CJAS pages on AJOL here: http://www.ajol.info/index.php/contjas/index.

  2. South African red data book - Aves

    CSIR Research Space (South Africa)

    Siegfried, WR

    1976-06-01

    Full Text Available Data sheets are provided on 101 South African bird species thought to be eligible for conservation attention. A list is also provided of 35 species which might qualify for inclusion in a revised South African Red Data Book....

  3. African palm ethno-medicine

    DEFF Research Database (Denmark)

    Gruca, Marta; Blach-Overgaard, Anne; Balslev, Henrik

    2015-01-01

    Ethnopharmacological relevance This study is the first to demonstrate the breadth and patterns of the medicinal applications of African palms. It sheds light on species with the potential to provide new therapeutic agents for use in biomedicine; and links the gap between traditional use of palms...... be directed at the central African region, because palm species richness (and plant species richness in general) is particularly high in this area, and only few ethno-botanical studies available have focused on this region. Conclusion The wide time span covered by our database (3500 years) shows that African...... palms have been used medicinally by many societies across the continent from time immemorial until today. Most medicinal use records for African palms were found in two categories that relate to most prevailing diseases and disorders in the region. By analyzing ethno-medicinal studies in one database we...

  4. The African monogenean gyrodactylid genus Macrogyrodactylus Malmberg, 1957, and the reporting of three species of the genus of Clarias gariepinus in South Africa.

    Science.gov (United States)

    Khalil, L F; Mashego, S N

    1998-12-01

    Three different species of the genus Macrogyrodactylus Malmberg, 1957, collected from the gills and skin of Clarias gariepinus (Burchell, 1822) from the Middle Letaba Dam and Mokgoma-Matlala Dam in South Africa were examined and identified. This is the first record of a species of the genus in South Africa. The three species are M. congolensis (Prudhoe, 1957)--found on the skin, M. clarii Gussev, 1961 and M. karibae Douellou & Chishawa, 1995--found on the gills. The last species is elevated to the status of a species having been described previously as a subspecies of M. congolensis. The present study presents and discusses the value of some of the taxonomic characters which can be used to differentiate the species of the genus. The shape and size of the sclerites of the haptor are found to be the most reliable characters. Only four species of the genus, namely M. polypteri and the three above-named species are regarded to be valid. Three species, namely M. latesi Paperna, 1969, M. anabantii Paperna, 1973 and M. ctenopomii Paperna, 1973 are regarded as species inquirenda. Generic diagnoses, measurements and illustrations of the sclerites of the four valid species are presented and a key for their differentiation is provided. The development of the gyrodactylid population on C. gariepinus during the filling of the Middle Letaba Dam in South Africa is discussed.

  5. Evolution of Acoustic Behaviour in African Bufo (Anura: Bufonidae ...

    African Journals Online (AJOL)

    Mating calls are known for 29 species of African Bufo belonging to 11 species groups. Twenty-five African species, representing eight species groups (including four groups or complexes having 2N=22) have calls which Martin (1972) termed Type I. This call type is also found in Schismaderma carens, Nectophrynoides ...

  6. Altitudinal gradients, biogeographic history and microhabitat adaptation affect fine-scale spatial genetic structure in African and Neotropical populations of an ancient tropical tree species.

    Directory of Open Access Journals (Sweden)

    Paloma Torroba-Balmori

    Full Text Available The analysis of fine-scale spatial genetic structure (FSGS within populations can provide insights into eco-evolutionary processes. Restricted dispersal and locally occurring genetic drift are the primary causes for FSGS at equilibrium, as described in the isolation by distance (IBD model. Beyond IBD expectations, spatial, environmental or historical factors can affect FSGS. We examined FSGS in seven African and Neotropical populations of the late-successional rain forest tree Symphonia globulifera L. f. (Clusiaceae to discriminate the influence of drift-dispersal vs. landscape/ecological features and historical processes on FSGS. We used spatial principal component analysis and Bayesian clustering to assess spatial genetic heterogeneity at SSRs and examined its association with plastid DNA and habitat features. African populations (from Cameroon and São Tomé displayed a stronger FSGS than Neotropical populations at both marker types (mean Sp = 0.025 vs. Sp = 0.008 at SSRs and had a stronger spatial genetic heterogeneity. All three African populations occurred in pronounced altitudinal gradients, possibly restricting animal-mediated seed dispersal. Cyto-nuclear disequilibria in Cameroonian populations also suggested a legacy of biogeographic history to explain these genetic patterns. Conversely, Neotropical populations exhibited a weaker FSGS, which may reflect more efficient wide-ranging seed dispersal by Neotropical bats and other dispersers. The population from French Guiana displayed an association of plastid haplotypes with two morphotypes characterized by differential habitat preferences. Our results highlight the importance of the microenvironment for eco-evolutionary processes within persistent tropical tree populations.

  7. Population genetics of African ungulates

    DEFF Research Database (Denmark)

    Lorenzen, Eline

    Molecular genetic techniques were used to gain insights into the evolutionary forces that have shaped the present day diversity of African savannah ungu-lates, which constitute the most species-rich mega faunal assemblage on earth. The studies included in this thesis represent individual species-...

  8. Population genetics of African ungulates

    DEFF Research Database (Denmark)

    Lorenzen, Eline

    Molecular genetic techniques were used to gain insights into the evolutionary forces that have shaped the present day diversity of African savannah ungu-lates, which constitute the most species-rich mega faunal assemblage on earth. The studies included in this thesis represent individual species...

  9. African Trypanosomiasis

    Science.gov (United States)

    2011-06-01

    a disease of horses, mules, camels , and cattle. African trypanosomiasis has probably played an impor- tant role in recorded history from antiquity...Saunders; 1929:706. 6. Baker JR. The subspecific taxonomy of Trypanosoma brucei. Parasite. 1995;2:3-12. 7. Control and surveillance of African

  10. African Zoology

    African Journals Online (AJOL)

    African Zoology, a peer-reviewed research journal, publishes original scientific contributions and critical reviews that focus principally on African fauna in terrestrial, freshwater, and marine ecosystems. Research from other regions that advances practical and theoretical aspects of zoology will be considered. Rigorous ...

  11. Tree species identification in an African Savanna with airborne imaging spectroscopy and LiDAR from the Carnegie Airborne Observatory (CAO) using stacked support vector machines

    Science.gov (United States)

    Baldeck, C. A.; Colgan, M.; Féret, J.; Asner, G. P.

    2012-12-01

    Airborne remote sensing data provide promising opportunities for species identification of individual tree and shrub crowns across large areas which cannot be mapped from the ground. Previous investigations of the potential for species identification of crowns from airborne data have focused on pixel-level information (0.5-1m2), and thus have been unable to take advantage of the structural information that exist at the crown level. Hyperspectral data consisting of 58 bands from 517 to 1054nm and LiDAR (light detection and ranging) data providing vegetation height information were acquired over several landscapes within Kruger National Park, South Africa, by the CAO in 2008 at 1.1m spatial resolution. Over 1,000 individual trees and shrubs were mapped and identified in the field to construct species spectral and structural libraries. We used stacked support vector machines (SVM) that incorporate pixel-level spectral information and crown-level structural information to predict species identity for individual tree crowns. The addition of a crown-level classification step that incorporates crown structural information significantly improved model accuracy by ~6% and our prediction accuracy of the final model was ~75% for 16 species classes. This model was then used to predict the species identity of individual crowns across multiple airborne-mapped landscapes, made possible by an automated crown segmentation algorithm. The resultant species maps will make it possible to examine the environmental controls over individual species distributions and tree community composition, and provide important landscape-scale species distribution information relevant to park management and conservation.

  12. Differentiation of three common deep-water hermit crabs (Crustacea, Decapoda, Anomura, Parapaguridae) from the South African demersal abundance surveys, including the description of a new species of Paragiopagurus Lemaitre, 1996.

    Science.gov (United States)

    Landschoff, Jannes; Lemaitre, Rafael

    2017-01-01

    Deep-water hermit crabs of the family Parapaguridae can be abundant (up to 20 kg or 1000 hermit crab individuals per haul) in the trawl bycatch collected during South African demersal abundance research surveys. Until recently, only two parapagurid species had been recognized in the bycatch; Parapagurus bouvieri Stebbing, 1910, and Sympagurus dimorphus (Studer, 1883). Detailed examination of numerous samples of parapagurid specimens from research surveys revealed the existence of a third, undescribed species previously confounded with S. dimorphus , but in fact belonging to a different genus. This new species, Paragiopagurus atkinsonae sp. n. is the 25 th in the genus Paragiopagurus Lemaitre, 1996, and has been found only in a small region on the West Coast shelf of South Africa, at depths of 199-277 m. The species is herein fully described and illustrated, including colour images, µCT scans of selected body parts, and CO1 barcode data. The new species is morphologically most similar to P. ventilatus Lemaitre, 2004, a species associated with hydrothermal vents, but differs in armature of the fourth antennal segment (armed with a spine on the dorsolateral distal angle vs. unarmed in P. ventilatus ); setation of the antennal flagella (nearly naked vs. with dense setae in P. ventilatus ); plumose setation on the third maxillipeds and basal segments of chelipeds (absent vs. present in P. ventilatus ); number of rows of scales on the propodal rasp of pereopod 4 (two or three rows vs. one row in P. ventilatus ); and degree of telson asymmetry (weakly asymmetrical vs. strongly asymmetrical in P. ventilatus ). Paragiopagurus atkinsonae sp. n. is superficially similar to S. dimorphus , with males of the two species showing the same extreme degree of sexual dimorphism on the right cheliped, general light orange colouration, and frequent use of colonial zoanthid carcinoecia for pleonal protection. To aid in future identifications and to facilitate data gathering during

  13. Differentiation of three common deep-water hermit crabs (Crustacea, Decapoda, Anomura, Parapaguridae from the South African demersal abundance surveys, including the description of a new species of Paragiopagurus Lemaitre, 1996

    Directory of Open Access Journals (Sweden)

    Jannes Landschoff

    2017-05-01

    Full Text Available Deep-water hermit crabs of the family Parapaguridae can be abundant (up to 20 kg or 1000 hermit crab individuals per haul in the trawl bycatch collected during South African demersal abundance research surveys. Until recently, only two parapagurid species had been recognized in the bycatch; Parapagurus bouvieri Stebbing, 1910, and Sympagurus dimorphus (Studer, 1883. Detailed examination of numerous samples of parapagurid specimens from research surveys revealed the existence of a third, undescribed species previously confounded with S. dimorphus, but in fact belonging to a different genus. This new species, Paragiopagurus atkinsonae sp. n. is the 25th in the genus Paragiopagurus Lemaitre, 1996, and has been found only in a small region on the West Coast shelf of South Africa, at depths of 199–277 m. The species is herein fully described and illustrated, including colour images, µCT scans of selected body parts, and CO1 barcode data. The new species is morphologically most similar to P. ventilatus Lemaitre, 2004, a species associated with hydrothermal vents, but differs in armature of the fourth antennal segment (armed with a spine on the dorsolateral distal angle vs. unarmed in P. ventilatus; setation of the antennal flagella (nearly naked vs. with dense setae in P. ventilatus; plumose setation on the third maxillipeds and basal segments of chelipeds (absent vs. present in P. ventilatus; number of rows of scales on the propodal rasp of pereopod 4 (two or three rows vs. one row in P. ventilatus; and degree of telson asymmetry (weakly asymmetrical vs. strongly asymmetrical in P. ventilatus. Paragiopagurus atkinsonae sp. n. is superficially similar to S. dimorphus, with males of the two species showing the same extreme degree of sexual dimorphism on the right cheliped, general light orange colouration, and frequent use of colonial zoanthid carcinoecia for pleonal protection. To aid in future identifications and to facilitate data gathering

  14. A molecular phylogeny of Equatorial African Lacertidae, with the description of a new genus and species from eastern Democratic Republic of the Congo

    Science.gov (United States)

    Greenbaum, Eli; Villanueva, Cesar O.; Kusamba, Chifundera; Aristote, Mwenebatu M.; Branch, William R.

    2011-01-01

    Currently, four species of the lacertid lizard genus Adolfus are known from Central and East Africa. We sequenced up to 2,825 bp of two mitochondrial (16S and cyt b) and two nuclear (c-mos and RAG1) genes from 41 samples of Adolfus (representing every species), two species each of Gastropholis and Holaspis, and in separate analyses combined this data with GenBank sequences of all other Eremiadini genera and four Lacertini outgroups. Data from DNA sequences were analyzed with maximum parsimony (PAUP), maximum-likelihood (RAxML) and Bayesian inference (MrBayes) criteria. Results demonstrated that Adolfus is not monophyletic: A. africanus (type species), A. alleni and A. jacksoni are sister taxa, whereas A. vauereselli and a new species from the Itombwe Plateau of Democratic Republic of the Congo are in a separate lineage. Holaspis and Gastropholis were recovered in separate clades. Based on this molecular data, relatively substantial sequence divergence and multiple morphological differences, we describe a new genus of lacertid for the lineage including A. vauereselli and the new Itombwe species. The recognition of this new, endemic genus underscores the conservation importance of the Albertine Rift, especially the Itombwe Plateau, a unique region that is severely threatened by unchecked deforestation, mining and poaching. PMID:22121299

  15. African Journals Online: African Studies

    African Journals Online (AJOL)

    Items 1 - 50 of 56 ... African Journal of Library, Archives and Information Science is established mainly to provide a forum for librarians, archivists, documentalists, information scientists and other information related professionals in Africa to report their research findings but with emphasis on African setting. The Journal is ...

  16. Genomic characterization of Ensifer aridi, a proposed new species of nitrogen-fixing rhizobium recovered from Asian, African and American deserts.

    Science.gov (United States)

    Le Quéré, Antoine; Tak, Nisha; Gehlot, Hukam Singh; Lavire, Celine; Meyer, Thibault; Chapulliot, David; Rathi, Sonam; Sakrouhi, Ilham; Rocha, Guadalupe; Rohmer, Marine; Severac, Dany; Filali-Maltouf, Abdelkarim; Munive, Jose-Antonio

    2017-01-14

    Nitrogen fixing bacteria isolated from hot arid areas in Asia, Africa and America but from diverse leguminous plants have been recently identified as belonging to a possible new species of Ensifer (Sinorhizobium). In this study, 6 strains belonging to this new clade were compared with Ensifer species at the genome-wide level. Their capacities to utilize various carbon sources and to establish a symbiotic interaction with several leguminous plants were examined. Draft genomes of selected strains isolated from Morocco (Merzouga desert), Mexico (Baja California) as well as from India (Thar desert) were produced. Genome based species delineation tools demonstrated that they belong to a new species of Ensifer. Comparison of its core genome with those of E. meliloti, E. medicae and E. fredii enabled the identification of a species conserved gene set. Predicted functions of associated proteins and pathway reconstruction revealed notably the presence of transport systems for octopine/nopaline and inositol phosphates. Phenotypic characterization of this new desert rhizobium species showed that it was capable to utilize malonate, to grow at 48 °C or under high pH while NaCl tolerance levels were comparable to other Ensifer species. Analysis of accessory genomes and plasmid profiling demonstrated the presence of large plasmids that varied in size from strain to strain. As symbiotic functions were found in the accessory genomes, the differences in symbiotic interactions between strains may be well related to the difference in plasmid content that could explain the different legumes with which they can develop the symbiosis. The genomic analysis performed here confirms that the selected rhizobial strains isolated from desert regions in three continents belong to a new species. As until now only recovered from such harsh environment, we propose to name it Ensifer aridi. The presented genomic data offers a good basis to explore adaptations and functionalities that enable them

  17. First record of the cycad blue, Chilades pandava, in Egypt – a new invasive butterfly species in the Mediterranean region and on the African continent (Lepidoptera: Lycaenidae)

    Czech Academy of Sciences Publication Activity Database

    Fric, Zdeněk; Dickinson, R.; Fetouh, G.; Larsen, T. B.; Schön, W.; Wiemers, M.

    2014-01-01

    Roč. 22, č. 2 (2014), s. 315-319 ISSN 1021-3589 Grant - others:GA JU(CZ) 168/2013/P Institutional support: RVO:60077344 Keywords : invasive species * mitochondrial DNA * haplotype network Subject RIV: EG - Zoology Impact factor: 0.365, year: 2014 http://www.bioone.org/doi/pdf/10.4001/003.022.0205

  18. Using social media to measure the contribution of red list species to the nature-based tourism potential of African protected areas

    DEFF Research Database (Denmark)

    Willemen, Louise; Cottam, Andrew J.; Drakou, Evangelia G.

    2015-01-01

    assessments. The index directly links species presence to the tourism potential of protected areas, making the connection between nature and human benefits explicit, but excludes other important contributing factors for tourism, such as accessibility and safety. This social media based index provides a broad...

  19. A molecular phylogeny of Afromontane dwarf geckos (Lygodactylus) reveals a single radiation and increased species diversity in a South African montane center of endemism.

    Science.gov (United States)

    Travers, Scott L; Jackman, Todd R; Bauer, Aaron M

    2014-11-01

    Afromontane habitats throughout eastern sub-Saharan Africa support remarkable levels of microendemism. However, despite being the subject of decades of research interest, biogeographical patterns of diversification throughout this disjunct montane system still remain largely unknown. We examined the evolutionary relationships of diurnal dwarf geckos (Lygodactylus) from several Afromontane regions throughout southeastern Africa, focusing primarily on two species groups (rex and bonsi groups). Using both mitochondrial and nuclear markers, we generate a molecular phylogeny containing all members of the rex and bonsi groups, to evaluate the monophyly of these groups along with previous biogeographic hypotheses suggesting independent southward invasions into the greater Drakensberg Afromontane center of endemism in northeastern South Africa by each group. Our results provide no support for these taxonomic and biogeographic hypotheses, and instead reveal geographically circumscribed patterns of diversification. One clade is restricted to the highlands of southern Malawi and northern Mozambique and the other to the greater Drakensberg region of northeastern South Africa and Swaziland. Interestingly, L. bernardi from the Nyanga Highlands of eastern Zimbabwe is nested within the primarily savanna-dwelling capensis group. We use Bayesian species delimitation methods to evaluate species limits within the greater Drakensberg clade, which support the elevation of the subspecies of L. ocellatus and L. nigropunctatus, thus bringing the total to eight species within a relatively confined geographic area. These results further highlight the greater Drakensberg Afromontane region as both an important center of endemism, as well as a center of diversification contributing to the accumulation of southern Africa's rich species diversity. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. How to improve fertility of African soils? Leguminous fallows (Cameroon), addition of farmyard manure and mineral fertilizer (Kenya), organic residues management and introduction of N2 fixing species in forest plantations (Congo).

    Science.gov (United States)

    Koutika, Lydie-Stella; Mareschal, Louis; Mouanda, Cadeau; Epron, Daniel

    2014-05-01

    Most of African soils are inherently infertile and poor in nutrients mainly nitrogen and phosphorus. Several practices are used to improve soil fertility, increase productivity and ensure their sustainability. Soil fertility in the leguminous fallows was evaluated through particulate organic matter (POM), the more active part of soil organic matter (SOM) in Cameroon. The combination of mineral and organic (manure) fertilizers increased microbial P biomass allowing the release of P along the plant growing period in the Kenyan soils. Organic residues management and introduction of nitrogen fixing species (Acacia) were used to improve soil fertility and sustain forest productivity on the coastal plains of Congo. SOM fractionation was made under Pueraria, Mucuna fallows and natural regrowth mainly Chromolaena and under 3 forest plantation treatments installed in previous savanna: 1) no input, 2) normal input, and 3) double input of organic residues. Microbial P biomass and sequential P fractionation were evaluated in high and low P fixing soils. N, C, available P and pH were determined on soil sampled in acacia (100A), eucalypt (100E) and mixed-species (50A:50E) stands. N and P were determined in aboveground litters and in leaves, bark and wood of trees. The two leguminous fallows increased N content in POM fractions i.e., N >1% for Pueraria and Mucuna against N0.06%) compared to under the pure eucalypt stand (N1% in the mixed stand and C< 0.9 in the pure Eucalyptus stand).

  1. Induced spawning, survival and growth of an African catfish hybrid ...

    African Journals Online (AJOL)

    Induced spawning, survival and growth of an African catfish hybrid (female Clarias gariepinus and male Clarias anguillaris ) fingerlings relative to their parental species in the mount Cameroon region.

  2. African leafy vegetables in South Africa

    African Journals Online (AJOL)

    In this article the term 'African leafy vegetables' was adopted to refer to the collective of plant species which are used as leafy vegetables and which are referred to as morogo or imifino by African people in South Africa. Function is central in this indigenous concept, which is subject to spatial and temporal variability in terms ...

  3. Isolation by distance and isolation by environment contribute to population differentiation in Protea repens (Proteaceae L.), a widespread South African species.

    Science.gov (United States)

    Prunier, Rachel; Akman, Melis; Kremer, Colin T; Aitken, Nicola; Chuah, Aaron; Borevitz, Justin; Holsinger, Kent E

    2017-05-01

    The Cape Floristic Region (CFR) of South Africa is renowned for its botanical diversity, but the evolutionary origins of this diversity remain controversial. Both neutral and adaptive processes have been implicated in driving diversification, but population-level studies of plants in the CFR are rare. Here, we investigate the limits to gene flow and potential environmental drivers of selection in Protea repens L. (Proteaceae L.), a widespread CFR species. We sampled 19 populations across the range of P. repens and used genotyping by sequencing to identify 2066 polymorphic loci in 663 individuals. We used a Bayesian F ST outlier analysis to identify single-nucleotide polymorphisms (SNPs) marking genomic regions that may be under selection; we used those SNPs to identify potential drivers of selection and excluded them from analyses of gene flow and genetic structure. A pattern of isolation by distance suggested limited gene flow between nearby populations. The populations of P. repens fell naturally into two or three groupings, which corresponded to an east-west split. Differences in rainfall seasonality contributed to diversification in highly divergent loci, as do barriers to gene flow that have been identified in other species. The strong pattern of isolation by distance is in contrast to the findings in the only other widespread species in the CFR that has been similarly studied, while the effects of rainfall seasonality are consistent with well-known patterns. Assessing the generality of these results will require investigations of other CFR species. © 2017 Prunier et al. Published by the Botanical Society of America. This work is licensed under a Creative Commons Attribution License (CC-BY-NC).

  4. Immunizations and African Americans

    Science.gov (United States)

    ... Data > Minority Population Profiles > Black/African American > Immunizations Immunizations and African Americans African American adults are less ... 19 to 35 months had comparable rates of immunization. African American women are as likely to have ...

  5. East African rarities committee report | Fisher | Scopus: Journal of ...

    African Journals Online (AJOL)

    East African Rarities Committee (EARC) Special Report Species included for East African countries in Britton (1980) which have since been considered unacceptable. East African Rarities Committee Report 2013–2015. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD ...

  6. Burrowing crickets endemic to summits in Mauritius (Orthoptera, Gryllidae): occupation of similar niches by species possibly derived from Australasian and African colonists.

    Science.gov (United States)

    Hugel, Sylvain

    2014-08-15

    Two ground burrowing crickets are described from the oceanic island of Mauritius (South Western Indian Ocean): Gialaia (Eugialaia) strasbergi n. sp. belongs to a subgenus that was only known from Papua-New Guinea, and Taciturna baiderae n.sp. belongs to a genus that was only known from South Africa. Taciturna baiderae n. sp. displays a maternal care behavior to clutch of eggs and offspring. Elements of the biology of these two new species are given and their conservation status is assessed. 

  7. The comparative phylogeography of fruit bats of the tribe Scotonycterini (Chiroptera, Pteropodidae) reveals cryptic species diversity related to African Pleistocene forest refugia.

    Science.gov (United States)

    Hassanin, Alexandre; Khouider, Souraya; Gembu, Guy-Crispin; Goodman, Steven M; Kadjo, Blaise; Nesi, Nicolas; Pourrut, Xavier; Nakouné, Emmanuel; Bonillo, Céline

    2015-03-01

    The hypothesis of Pleistocene forest refugia was tested using comparative phylogeography of Scotonycterini, a fruit bat tribe endemic to Africa containing four species: Scotonycteris zenkeri, Casinycteris argynnis, C. campomaanensis, and C. ophiodon. Patterns of genetic structure were assessed using 105 Scotonycterini (including material from three holotypes) collected at 37 localities, and DNA sequences from the mitochondrial cytochrome b gene (1140 nt) and 12 nuclear introns (9641 nt). Phylogenetic trees and molecular dating were inferred by Bayesian methods. Multilocus analyses were performed using supermatrix, SuperTRI, and *BEAST approaches. Mitochondrial analyses reveal strong phylogeographical structure in Scotonycteris, with four divergent haplogroups (4.9-8.7%), from Upper Guinea, Cameroon, western Equatorial Africa, and eastern Democratic Republic of the Congo (DRC). In C. argynnis, we identify two mtDNA haplogroups corresponding to western and eastern Equatorial Africa (1.4-2.1%). In C. ophiodon, the mtDNA haplotypes from Cameroon and Ivory Coast differ by only 1.3%. Nuclear analyses confirm the validity of the recently described C. campomaanensis and indicate that western and eastern populations of C. argynnis are not fully isolated. All mtDNA clusters detected in Scotonycteris are found to be monophyletic based on the nuclear dataset, except in eastern DRC. In the nuclear tree, the clade from western Equatorial Africa is closely related to individuals from eastern DRC, whereas in the mitochondrial tree it appears to be the sister-group of the Cameroon clade. Migrate-n analyses support gene flow from western Equatorial Africa to eastern DRC. Molecular dating indicates that Pleistocene forest refugia have played an important role in shaping the evolution of Scotonycterini, with two phases of allopatric speciation at approximately 2.7 and 1.6 Mya, resulting from isolation in three main forest areas corresponding to Upper Guinea, Cameroon, and Equatorial

  8. Determination of the prevalence of African trypanosome species in indigenous dogs of Mambwe district, eastern Zambia, by loop-mediated isothermal amplification.

    Science.gov (United States)

    Lisulo, Malimba; Sugimoto, Chihiro; Kajino, Kiichi; Hayashida, Kyouko; Mudenda, Macarthy; Moonga, Ladslav; Ndebe, Joseph; Nzala, Selestine; Namangala, Boniface

    2014-01-10

    Dogs have been implicated to serve as links for parasite exchange between livestock and humans and remain an important source of emerging and re-emerging diseases including trypanosome infections. Yet, canine African trypanosomosis (CAT), particularly in indigenous dogs (mongrel breed) remains under- reported in literature. This study evaluated the performance of loop-mediated isothermal amplification (LAMP) in detecting trypanosomes in blood from indigenous dogs of tsetse-infested Mambwe district in eastern Zambia. A cross sectional survey of CAT was conducted within 5 chiefdoms (Msoro, Kakumbi, Munkanya, Nsefu, Malama) of Mambwe district, eastern Zambia, during October 2012. Blood samples from 237 indigenous hunting dogs were collected and screened by microscopy and LAMP. Of the 237 dogs screened for CAT, 14 tested positive by microscopy (5.9%; 95% CI: 2.9 - 8.9%), all of which also tested positive by LAMP. In addition, LAMP detected 6 additional CAT cases, bringing the total cases detected by LAMP to 20 (8.4%; 95% CI: 4.9 - 12.0%). Irrespective of the detection method used, CAT was only recorded from 3 chiefdoms (Munkanya, Nsefu, Malama) out of the 5. According to LAMP, these infections were caused by Trypanosoma congolense, Trypanosoma brucei brucei and the zoonotic Trypanosoma brucei rhodesiense. Although these CAT cases generally did not manifest clinical illness, an association was observed between infection with Trypanosoma brucei subspecies and occurrence of corneal opacity. This communication reports for the first time the occurrence of CAT in indigenous Zambian dogs. Our study indicates that LAMP is a potential diagnostic tool for trypanosome detection in animals. LAMP was more sensitive than microscopy and was further capable of distinguishing the closely related T. b. brucei and T. b. rhodesiense. In view of the sporadic cases of re-emerging HAT being reported within the Luangwa valley, detection of the human serum resistant associated (SRA) gene in

  9. A micro X-ray computed tomography dataset of South African hermit crabs (Crustacea: Decapoda: Anomura: Paguroidea) containing scans of two rare specimens and three recently described species.

    Science.gov (United States)

    Landschoff, Jannes; Du Plessis, Anton; Griffiths, Charles L

    2018-04-01

    Along with the conventional deposition of physical types at natural history museums, the deposition of 3-dimensional (3D) image data has been proposed for rare and valuable museum specimens, such as irreplaceable type material. Micro computed tomography (μCT) scan data of 5 hermit crab species from South Africa, including rare specimens and type material, depicted main identification characteristics of calcified body parts. However, low-image contrasts, especially in larger (>50 mm total length) specimens, did not allow sufficient 3D reconstructions of weakly calcified and fine characteristics, such as soft tissue of the pleon, mouthparts, gills, and setation. Reconstructions of soft tissue were sometimes possible, depending on individual sample and scanning characteristics. The raw data of seven scans are publicly available for download from the GigaDB repository. Calcified body parts visualized from μCT data can aid taxonomic validation and provide additional, virtual deposition of rare specimens. The use of a nondestructive, nonstaining μCT approach for taxonomy, reconstructions of soft tissue structures, microscopic spines, and setae depend on species characteristics. Constrained to these limitations, the presented dataset can be used for future morphological studies. However, our virtual specimens will be most valuable to taxonomists who can download a digital avatar for 3D examination. Simultaneously, in the event of physical damage to or loss of the original physical specimen, this dataset serves as a vital insurance policy.

  10. The relationship between habitat complexity and nursery provision for an estuarine-dependent fish species in a permanently open South African Estuary

    Science.gov (United States)

    Leslie, Timothy; James, Nicola C.; Potts, Warren M.; Rajkaran, Anusha

    2017-11-01

    Estuarine-dependent marine fish species rely on shallow, sheltered and food rich habitats for protection from predators, growth and ultimately recruitment to adult populations. Hence, habitats within estuaries function as critical nursery areas for an abundance of fish species. However, these habitats vary in the degree of nursery function they provide and few studies have quantitatively assessed the relative nursery value of different habitat types within estuaries, particularly in the context of habitat complexity. This study aimed to assess the nursery value of the dominant vegetated habitats, namely the submergent Zostera capensis (Setch.) (seagrass) beds and emergent Spartina maritima (Curtis) Fernald (salt marsh) beds in the Bushmans Estuary, South Africa. Biomass and stem density were sampled seasonally in order to gain insight into the vegetation dynamics of seagrass and salt marsh beds. Aerial cover, canopy height and underwater camera imagery were used to develop multiple complexity indices for prioritizing habitat complexity. The relatively consistent results of the dimensionless indices (interstitial space indices and fractal geometry) suggest that Z. capensis exhibits an overall greater degree of complexity than S. maritima, and hence it can be expected that fish abundance is likely to be higher in Z. capensis beds than in S. maritima habitats. Underwater video cameras were deployed in seagrass, salt marsh and sand flat habitats to assess the relative abundance and behaviour of the estuarine-dependent sparid Rhabosargus holubi (Steindachner 1881) in different habitats. The relative abundance of R. holubi was significantly higher in Z. capensis seagrass than S. maritima salt marsh and sand flats, whilst the behaviour of R. holubi indicated a high degree of habitat use in structured habitats (both Z. capensis and S. martima) and a low degree of habitat use in unstructured sand flat habitats.

  11. Salmonella Sepsis in African Children

    African Journals Online (AJOL)

    Infection with both Salmonella typhiand non-typhi salmonella. (NTS) is common among children in many African countries. Salmonella typhi predominates among older children and adults with the typical localising features of enteric fever. Nontyphoid salmonellae species are more often reported among children under 5 ...

  12. African Environment

    African Journals Online (AJOL)

    Environmental Studies and Regional Planning Bulletin African Environment is published in French and English, and for some issues, in Arabic. (only the issue below has been received by AJOL). Vol 10, No 3 (1999). DOWNLOAD FULL TEXT Open Access DOWNLOAD FULL TEXT Subscription or Fee Access. Table of ...

  13. African Journals Online: Central African Republic

    African Journals Online (AJOL)

    African Journals Online: Central African Republic. Home > African Journals Online: Central African Republic. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This ...

  14. Survival Value and Sugar Access of Four East African Plant Species Attractive to a Laboratory Strain of Sympatric Anopheles gambiae (Diptera: Culicidae).

    Science.gov (United States)

    Nikbakhtzadeh, M R; Terbot, J W; Foster, W A

    2016-05-31

    Mosquitoes derive energy from plant sugar, thereby promoting survival and reproduction. Its survival value to females plays a key role in the vectorial capacity of mosquito populations. Previous olfactometry assays of responsiveness demonstrated that Senna didymobotrya Fresenius, Parthenium hysterophorus, L. Senna occidentalis, (L) and Lantana camara L were among the most attractive plants for the Mbita strain of Anopheles gambiae s.s. Giles in eastern Africa. Here, we provide experimental evidence that three of these four species also provide varying but substantial amounts of sugar for mosquito survival, whereas a fourth does not. Rank order of survival of both sexes of mosquitoes housed with these plants was as follows: S. didymobotrya was highest, followed by S. occidentalis and L. camara, whereas survival on P. hysterophorus was only slightly better than on only water. A positive control group, housed with 10% sucrose, survived well but fell significantly short of those with S. didymobotrya A causal connection between survival and sugar availability was established by exposing mosquitoes to plants overnight, and then testing them for the presence and amount of undigested fructose. Fructose positivity was most frequent in those exposed to L. camara, whereas greatest amounts of fructose were obtained from S. occidentalis and S. didymobotrya Parthenium hysterophorus scored lowest in both categories. We conclude that attractiveness and sugar availability are often, but not always, concordant. It remains unclear why P. hysterophorus should be attractive if it offers little sugar and does not prolong survival. Furthermore, the cause behind the superior survival benefit of S. didymobotrya, compared with 10% sucrose, is unknown. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Molecular Characterization of Staphylococcus aureus Isolated from Bovine Mastitis and Close Human Contacts in South African Dairy Herds: Genetic Diversity and Inter-Species Host Transmission

    Science.gov (United States)

    Schmidt, Tracy; Kock, Marleen M.; Ehlers, Marthie M.

    2017-01-01

    Staphylococcus aureus is one of the most common etiological agents of contagious bovine mastitis worldwide. The purpose of this study was to genetically characterize a collection of S. aureus isolates (bovine = 146, human = 12) recovered from cases of bovine mastitis and nasal swabs of close human contacts in the dairy environment. Isolates were screened for a combination of clinically significant antimicrobial and virulence gene markers whilst the molecular epidemiology of these isolates and possible inter-species host transmission was investigated using a combination of genotyping techniques. None of the isolates under evaluation tested positive for methicillin or vancomycin resistance encoding genes. Twenty seven percent of the bovine S. aureus isolates tested positive for one or more of the pyrogenic toxin superantigen (PTSAg) genes with the sec and sell genes predominating. Comparatively, 83% of the human S. aureus isolates tested positive for one or more PTSAg genes with a greater variety of genes being detected. Genomic DNA macrorestriction followed by pulsed-field gel electrophoresis (PFGE) of the bovine isolates generated 58 electrophoretic patterns which grouped into 10 pulsotypes at an 80% similarity level. The majority of the bovine isolates, 93.2% (136/146), clustered into four major pulsotypes. Seven sequence types (ST) were identified among the representative bovine S. aureus isolates genotyped, including: ST8 (CC8), ST97 (CC97), ST351 (CC705), ST352 (CC97), ST508 (CC45), ST2992 (CC97) and a novel sequence type, ST3538 (CC97). Based on PFGE analysis, greater genetic diversity was observed among the human S. aureus isolates. Bovine and human isolates from three sampling sites clustered together and were genotypically indistinguishable. Two of the isolates, ST97 and ST352 belong to the common bovine lineage CC97, and their isolation from close human contacts suggests zoonotic transfer. In the context of this study, the third isolate, ST8 (CC8), is

  16. Transcriptomic responses of Biomphalaria pfeifferi to Schistosoma mansoni: Investigation of a neglected African snail that supports more S. mansoni transmission than any other snail species

    Science.gov (United States)

    Bu, Lijing; Zhang, Si-Ming; Schilkey, Faye D.; Mkoji, Gerald M.; Loker, Eric S.

    2017-01-01

    Background Biomphalaria pfeifferi is highly compatible with the widespread human-infecting blood fluke Schistosoma mansoni and transmits more cases of this parasite to people than any other snail species. For these reasons, B. pfeifferi is the world’s most important vector snail for S. mansoni, yet we know relatively little at the molecular level regarding the interactions between B. pfeifferi and S. mansoni from early-stage sporocyst transformation to the development of cercariae. Methodology/Principal findings We sought to capture a portrait of the response of B. pfeifferi to S. mansoni as it occurs in nature by undertaking Illumina dual RNA-Seq on uninfected control B. pfeifferi and three intramolluscan developmental stages (1- and 3-days post infection and patent, cercariae-producing infections) using field-derived west Kenyan specimens. A high-quality, well-annotated de novo B. pfeifferi transcriptome was assembled from over a half billion non-S. mansoni paired-end reads. Reads associated with potential symbionts were noted. Some infected snails yielded fewer normalized S. mansoni reads and showed different patterns of transcriptional response than others, an indication that the ability of field-derived snails to support and respond to infection is variable. Alterations in transcripts associated with reproduction were noted, including for the oviposition-related hormone ovipostatin and enzymes involved in metabolism of bioactive amines like dopamine or serotonin. Shedding snails exhibited responses consistent with the need for tissue repair. Both generalized stress and immune factors immune factors (VIgLs, PGRPs, BGBPs, complement C1q-like, chitinases) exhibited complex transcriptional responses in this compatible host-parasite system. Significance This study provides for the first time a large sequence data set to help in interpreting the important vector role of the neglected snail B. pfeifferi in transmission of S. mansoni, including with an emphasis on

  17. Transcriptomic responses of Biomphalaria pfeifferi to Schistosoma mansoni: Investigation of a neglected African snail that supports more S. mansoni transmission than any other snail species.

    Directory of Open Access Journals (Sweden)

    Sarah K Buddenborg

    2017-10-01

    Full Text Available Biomphalaria pfeifferi is highly compatible with the widespread human-infecting blood fluke Schistosoma mansoni and transmits more cases of this parasite to people than any other snail species. For these reasons, B. pfeifferi is the world's most important vector snail for S. mansoni, yet we know relatively little at the molecular level regarding the interactions between B. pfeifferi and S. mansoni from early-stage sporocyst transformation to the development of cercariae.We sought to capture a portrait of the response of B. pfeifferi to S. mansoni as it occurs in nature by undertaking Illumina dual RNA-Seq on uninfected control B. pfeifferi and three intramolluscan developmental stages (1- and 3-days post infection and patent, cercariae-producing infections using field-derived west Kenyan specimens. A high-quality, well-annotated de novo B. pfeifferi transcriptome was assembled from over a half billion non-S. mansoni paired-end reads. Reads associated with potential symbionts were noted. Some infected snails yielded fewer normalized S. mansoni reads and showed different patterns of transcriptional response than others, an indication that the ability of field-derived snails to support and respond to infection is variable. Alterations in transcripts associated with reproduction were noted, including for the oviposition-related hormone ovipostatin and enzymes involved in metabolism of bioactive amines like dopamine or serotonin. Shedding snails exhibited responses consistent with the need for tissue repair. Both generalized stress and immune factors immune factors (VIgLs, PGRPs, BGBPs, complement C1q-like, chitinases exhibited complex transcriptional responses in this compatible host-parasite system.This study provides for the first time a large sequence data set to help in interpreting the important vector role of the neglected snail B. pfeifferi in transmission of S. mansoni, including with an emphasis on more natural, field-derived specimens. We

  18. African Journals Online (AJOL)

    African Journals Online (AJOL)

    ChemSearch Journal. Vol 48, No 3 (2018). South African Journal of Animal Science. Vol 8, No 1 (2018). African Journal of Chemical Education. Vol 48, No 2 (2018). South African Journal of Animal Science. Vol 48, No 1 (2018). South African Journal of Animal Science. Vol 7, No 1 (2018). South African Journal of Geomatics.

  19. on candida species

    African Journals Online (AJOL)

    Abstract. Background: Candida species (sp) is implicated in causing opportunistic disseminated mycotic complications in stage II. HIV patients. Cleistopholis patens is a West African medicinal tree reported to have significant antifungal activity against C. albicans. Objectives: This study aimed to determine the anti-candidal ...

  20. 75 FR 38069 - Injurious Wildlife Species; Listing the Boa Constrictor, Four Python Species, and Four Anaconda...

    Science.gov (United States)

    2010-07-01

    ... Python Species, and Four Anaconda Species as Injurious Reptiles AGENCY: Fish and Wildlife Service... regulations to add Indian python (Python molurus, including Burmese python Python molurus bivittatus), reticulated python (Broghammerus reticulatus or Python reticulatus), Northern African python (Python sebae...

  1. Strengthening African Union for African Integration: An African ...

    African Journals Online (AJOL)

    Toshiba

    globalization, there is strong need for African leaders to re-strategize a new world view of African role in African affairs ... need to cope with the forces of globalization and her impact on national sovereignty and threat to local ..... 2011 endorsed a framework, roadmap and architecture of the continental free trade area (CFTA).

  2. African Journals Online (AJOL)

    African Journals Online (AJOL)

    2017). South African Family Practice. Vol 30, No 4 (2017). South African Journal of Clinical Nutrition. Vol 22, No 3 (2017). Journal of Endocrinology, Metabolism and Diabetes of South Africa. AJOL African Journals Online. HOW TO USE AJOL.

  3. Retraction | Simon | African Zoology

    African Journals Online (AJOL)

    Panthera leo) ina. West African national park”. African Zoology is publishing an Editorial Expression of Concern regarding the following article: “New records of a threatened lion population (Panthera leo) in a West African national park” by ...

  4. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journal of Science and Technology; Educational leadership and management: theory, policy and practice. South African Journal of Education; Involute Spur Gear Template Development by Parametric Technique Using Computer Aided Design African Research Review; Drug interactions with tuberculosis therapy

  5. African Journals Online: Health

    African Journals Online (AJOL)

    bioline.org.br/hs. African Health Sciences encourages authors to now submit ... The African Journal of Drug & Alcohol Studies is an international scientific journal published by the African Centre for Research and Information on ...

  6. Microplastics in Inland African Waters

    DEFF Research Database (Denmark)

    Khan, Farhan; Mayoma, Bahati Sosthenes; Biginagwa, Fares John

    2017-01-01

    is known about the presence, sources, and fate of plastics (and microplastics (MPs)) within African waters. Research in marine regions, most notably around the coast of South Africa, describes the occurrence of MPs in seabirds and fish species. More recently environmental sampling studies in the same area...... have quantified plastics in both the water column and sediments. However, despite Africa containing some of the largest and deepest of the world’s freshwater lakes, including Lakes Victoria and Tanganyika as part of the African Great Lakes system, and notable freshwater rivers, such as the River Congo...... and the Nile, the extent of MPs within the inland waters remains largely unreported. In the only study to date to describe MP pollution in the African Great Lakes, a variety of polymers, including polyethylene, polypropylene, and silicone rubber, were recovered from the gastrointestinal tracts of Nile perch...

  7. Some remarks on the African wild ass

    NARCIS (Netherlands)

    Bemmel, van A.C.V.

    1972-01-01

    INTRODUCTION Without any doubt the African Wild Ass should be considered a species threatened with extinction. Therefore, it seems worth-while to collect as many data on this species as possible and to do this quickly. Data and material, however, are scarce. Many sportsmen and zoologists observed

  8. Species and endosymbiont diversity of Bemisia tabaci (Homoptera: Aleyrodidae) on vegetable crops in Senegal.

    Science.gov (United States)

    Hélène, Delatte; Rémy, Baudin; Nathalie, Becker; Anne-Laure, Girard; Traoré, Ramatoulaye Sidebe; Jean-Michel, Lett; Bernard, Reynaud

    2015-03-01

    Bemisia tabaci-transmitted geminiviruses are one of the major threats on cassava and vegetable crops in Africa. However, to date, few studies are available on the diversity of B. tabaci and their associated endosymbionts in Africa. More than 28 species have been described in the complex of B. tabaci cryptic species; among them, 2 are invasive pests worldwide: MED and MEAM1. In order to assess the species diversity of B. tabaci in vegetable crops in Senegal, several samplings in different localities, hosts and seasons were collected and analyzed with nuclear (microsatellite) and mitochondrial (COI) markers. The bacterial endosymbiont community was also studied for each sample. Two species were detected: MED Q1 and MEAM1 B. Patterns of MED Q1 (dominance on most of the samples and sites, highest nuclear and mitochondrial diversity and broader secondary endosymbiont community: Hamiltonella, Cardinium, Wolbachia and Rickettsia), point toward a predominant resident begomovirus vector group for MED Q1 on market gardening crops. Furthermore, the lower prevalence of the second species MEAM1 B, its lower nuclear and mitochondrial diversity and a narrower secondary endosymbiont community (Hamiltonella/Rickettsia), indicate that this genetic group is exotic and results from a recent invasion in this area. © 2014 Institute of Zoology, Chinese Academy of Sciences.

  9. Bacterial species identification getting easier | Tshikhudo | African ...

    African Journals Online (AJOL)

    The review provides a comprehensive appreciation of new and improved technologies such fatty acid profiling, sequence analysis of the 16S rRNA gene, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF), metabolic finger profiling using BIOLOG, ribotyping, together with the computational tools employed ...

  10. CLIMBING BEHAVIOUR IN THREE AFRICAN RODENT SPECIES ...

    African Journals Online (AJOL)

    came from the Transvaal lowveld and four from the Kalahari Gemsbok National Park. One was born in captivity. ThePraomys were descendants of wild -caught stock from around Pretoria. Two Saccostomus came from the Kalahari Gemsbok National Park and one from the Transvaal lowveld. The testing apparatus was a box ...

  11. Ignoring Authentic African Literature Means Ignoring Africans

    Science.gov (United States)

    Romano, Carlin

    2005-01-01

    Africa produces imaginative and authentic literature whose texture makes it impossible to think of Africans as statistics. African writers, however have to struggle to get recognized in America due to their culture and other racial and social differences, hence suggesting that efforts should be made to give authentic African literature its due.

  12. African Journal of Biotechnology - Vol 15, No 37 (2016)

    African Journals Online (AJOL)

    The rolling circle amplification and next generation sequencing approaches reveal genome wide diversity of Kenyan cassava mosaic geminivirus · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Ibrahim Soe, Richard Akromah, Daniel Nyadanu, Maxwell Darko ...

  13. Evolutionary time-scale of the begomoviruses: evidence from integrated sequences in the Nicotiana genome.

    Directory of Open Access Journals (Sweden)

    Pierre Lefeuvre

    Full Text Available Despite having single stranded DNA genomes that are replicated by host DNA polymerases, viruses in the family Geminiviridae are apparently evolving as rapidly as some RNA viruses. The observed substitution rates of geminiviruses in the genera Begomovirus and Mastrevirus are so high that the entire family could conceivably have originated less than a million years ago (MYA. However, the existence of geminivirus related DNA (GRD integrated within the genomes of various Nicotiana species suggests that the geminiviruses probably originated >10 MYA. Some have even suggested that a distinct New-World (NW lineage of begomoviruses may have arisen following the separation by continental drift of African and American proto-begomoviruses ∼110 MYA. We evaluate these various geminivirus origin hypotheses using Bayesian coalescent-based approaches to date firstly the Nicotiana GRD integration events, and then the divergence of the NW and Old-World (OW begomoviruses. Besides rejecting the possibility of a<2 MYA OW-NW begomovirus split, we could also discount that it may have occurred concomitantly with the breakup of Gondwanaland 110 MYA. Although we could only confidently narrow the date of the split down to between 2 and 80 MYA, the most plausible (and best supported date for the split is between 20 and 30 MYA--a time when global cooling ended the dispersal of temperate species between Asia and North America via the Beringian land bridge.

  14. African Communalism and Globalization

    African Journals Online (AJOL)

    info

    Abstract. The certainty of African philosophy during pre-colonial Africa is no longer in doubt. Doubting such a claim is denying the existence of the African race which may be self contradictory. As this work observes, African philosophy which is all encompassing, is inbuilt in African communalism through which indigenous ...

  15. Trends in African philosophy

    African Journals Online (AJOL)

    JONATHAN

    In the contention of Oladipo (2006), the debate on the idea of. African philosophy which has been divided into trends or schools, dates back to the 1960's and 70's, which constitute the modern epoch of African philosophy, when some African thinkers began to question the perspective that traditional African beliefs and.

  16. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the ... Egyptian Journal of Medical Human Genetics.

  17. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. AJOL is a Non-Profit Organisation based in ...

  18. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics.

  19. African Journals Online: Cameroon

    African Journals Online (AJOL)

    Items 1 - 8 of 8 ... African Anthropologist. African Anthropology is the journal of the Pan African Anthropological Association (PAAA). It provides a forum for African and Africanist anthropologists to publish research reports, articles, book reviews, news items and other useful information. It aims at stimulating the debate of ideas ...

  20. African Journals Online (AJOL)

    African Journals Online (AJOL)

    2018). South African Journal of Animal Science. Vol 8, No 1 (2018). African Journal of Chemical Education. Vol 48, No 2 (2018). South African Journal of Animal Science. Vol 48, No 1 (2018). South African Journal of Animal Science. Vol 7, No ...

  1. African Journals Online (AJOL)

    African Journals Online (AJOL)

    South African Journal of Education; Corporal punishment in South African schools : a neglected explanation for its Existence South African Journal of Education; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African ...

  2. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African academics. In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and ... Featured Country: South Africa, Featured Journal: Ergonomics SA ...

  3. African Journals Online: Peru

    African Journals Online (AJOL)

    PROMOTING ACCESS TO AFRICAN RESEARCH. AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES. African Journals Online: Peru. Home > African Journals Online: Peru. Log in or Register to get access to full text downloads. Username, Password, Remember me

  4. Short Communication Chromosome number of the South African ...

    African Journals Online (AJOL)

    ... comprising South African, Australian and New Zealand species, and corroborates the hypothesis of the radiation of the genus into the Southern and Northern hemispheres from the Indo-Pacific area. Keywords: chromosome number; Haliotis midae; Tethys model. African Journal of Marine Science 2008, 30(1): 195–198 ...

  5. Vocalizations of the South African cliff swallow Hirundo spilodera

    African Journals Online (AJOL)

    Vocalizations of the South African cliff swallow. Hirundo spilodera. A.A. Earle. National Museum, Bloemfontein. The vocalizations of both adult and juvenile South African cliff swallows Hirundo spilodera are described. This swallow has a large vocal repertoire considering that it is a highly colonial species, and at least seven ...

  6. Although South African sardine (or pilchard, Sardinops sagax) were ...

    African Journals Online (AJOL)

    spamer

    Although South African sardine (or pilchard,. Sardinops sagax) were first canned in 1935, commer- cial purse-seine fishing for the species was initiated only in 1943 to satisfy the war-time demand for canned fish, and major development of the South. African pelagic fishery took place only after the war. (Crawford 1979 ...

  7. Dolphins and African apes: comparisons of sympatric socio-ecology

    NARCIS (Netherlands)

    Bearzi, M.; Stanford, C.B.

    2007-01-01

    Dolphins and African apes are distantly related mammalian taxa that exhibit striking convergences in their socioecology. In both cetaceans and African apes, two or more closely related species sometimes occur in sympatry. However, detailed reviews of the ways in which sympatric associations of

  8. Strengthening African Union for African Integration: An African ...

    African Journals Online (AJOL)

    ... a collective effort to combat terrorism, ensure stability in the political system; and use a collective effort to combat pervasive corruption among African Countries. Corruption kills economic growth and demeans political legitimacy. These factors inhibit investment process hence, trading among African countries is very low.

  9. The evolution of African plant diversity

    Directory of Open Access Journals (Sweden)

    Hans Peter Linder

    2014-07-01

    Full Text Available Sub-Saharan Africa includes some 45,000 plant species. The spatial patterns of this diversity have been well explored. We can group the species into a set of biogeographical regions (largely co-incident with regions defined for terrestrial vertebrate groups. Furthermore, we know that the diversity is unevenly distributed, with southern Africa (especially the south-western tip disproportionally species rich, while the West African interior is disproportionally species poor. However, the origins of this diversity have only been explored for two anomalous African Floras (the Tropic-alpine Flora and the Cape Flora, whereas the origins of the diversity of the other floras are still unknown. Here I argue that six floras, with distinct geographical centres, different extra-African affinities, ages of radiation and radiation rates, can be delimited: the Austro-temperate, Tropic-alpine, Lowland forest, Tropic-montane, Savanna and Arid Floras. The oldest flora may be the Lowland forest Flora, and the most recent is the Tropic-alpine, which probably evolved during the Plio-Pleistocene on the summits of the East Africa volcanoes. My results suggest that the most rapidly radiating flora is the Austro-temperate Flora, while the other floras are all diversifying at more or less the same rate, this is also consistent with the current massive species richness in this flora (about half of the African species richness. The Austro-temperate Flora appears to be related to the floras of the other southern continents, the Tropic-alpine Flora to that of the Northern Hemisphere, and the four tropical floras to the tropical regions of the other continents, consistent with the theory of phylogenetic niche conservatism. Current African diversity may be the result of the sequential adding of new floras to the continent. Possibly the species poverty especially of the Lowland forest Flora may be the result of the spread of C4 grasslands and associated regular fires.

  10. AFRICAN BUFFALO OPTIMIZATION ico-pdf

    Directory of Open Access Journals (Sweden)

    Julius Beneoluchi Odili

    2016-02-01

    Full Text Available This is an introductory paper to the newly-designed African Buffalo Optimization (ABO algorithm for solving combinatorial and other optimization problems. The algorithm is inspired by the behavior of African buffalos, a species of wild cows known for their extensive migrant lifestyle. This paper presents an overview of major metaheuristic algorithms with the aim of providing a basis for the development of the African Buffalo Optimization algorithm which is a nature-inspired, population-based metaheuristic algorithm. Experimental results obtained from applying the novel ABO to solve a number of benchmark global optimization test functions as well as some symmetric and asymmetric Traveling Salesman’s Problems when compared to the results obtained from using other popular optimization methods show that the African Buffalo Optimization is a worthy addition to the growing number of swarm intelligence optimization techniques.

  11. Catalase activity of cassava (Manihot esculenta) plant under African ...

    African Journals Online (AJOL)

    aghomotsegin

    . E-mail: sabastina.amoako@kintampo-hrc.org. Tel: +233543550743. Abbreviations: CBSD, Cassava brown streak disease; ACMV, African cassava mosaic virus; ROS, reactive oxygen species; H2O2, hydrogen peroxide; BSA, bovine serum ...

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed ... Research in Hospitality Management. Vol 7, No 1 (2018). AFRREV IJAH: An International Journal of Arts and Humanities. Vol 12, No 1 (2018). African ...

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    2017). South African Family Practice. Vol 30, No 4 (2017). South African Journal of Clinical Nutrition. Vol 22, No 3 (2017). Journal of Endocrinology, Metabolism and Diabetes of South Africa. Vol 38, No 1 (2017). Nigerian Veterinary Journal.

  14. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. ... Featured Country: South Africa, Featured Journal: Southern African Linguistics and Applied Language Studies ...

  15. Liberalism and African Culture.

    Science.gov (United States)

    Sindima, Harvey

    1990-01-01

    Discusses the effect of liberalism on the African understanding of education, community, and religion. Describes ways in which the European intrusion, that is, colonial governments, schools, and churches, undermined traditional African life and thought. (DM)

  16. Depression and African Americans

    Science.gov (United States)

    ... You are here Home » Depression And African Americans Depression And African Americans Not “Just the Blues” Clinical ... or spiritual communities. Commonly Asked Questions about Clinical Depression How do I get help for clinical depression? ...

  17. African Studies Monographs

    African Journals Online (AJOL)

    The African Studies Monographs is a serial that promotes research and scholarship on the African perspective worldwide. This includes matters of philosophy, history, literature, arts and culture, environment, gender, politics, administration crisis management, etc.

  18. Avaliação da resistência de acessos de tomateiro a tospovírus e a geminivírus Evaluation of tomato accessions for tospovirus and geminivirus resistance

    Directory of Open Access Journals (Sweden)

    André Luiz Lourenção

    2004-06-01

    Full Text Available Treze linhagens avançadas e três cultivares de tomateiro foram avaliadas em condições de campo para resistência a tospovírus e a geminivírus, em Campinas (SP. O germoplasma avaliado compreendeu linhagens do grupo IAC e as cultivares Stevens, Franco e IPA-5. Um mesmo experimento foi instalado em duas épocas. Na primeira, o experimento foi conduzido de 12/2001 a 2/2002, e a única espécie de tospovírus incidente foi Tomato chlorotic spot virus (TCSV. Na segunda época, de 7 a 9/2002, houve infecção por Tomato yellow vein streak virus (TYVSV, sendo a avaliação realizada mediante determinação da porcentagem de plantas infectadas e pela intensidade dos sintomas, medida por escala de notas. Não houve discriminação dos tratamentos com base no primeiro critério, mas o uso de notas permitiu a diferenciação do germoplasma, com destaque para a linhagem IAC-S3-16. Considerando-se ambas as épocas, confirmou-se a suscetibilidade de 'IPA-5' aos dois patógenos e demonstrou-se o comportamento de resistência de 'Franco' a TCSV e a TYVSV. Ainda deve ser destacado o desempenho das linhagens IAC-S3-54, IAC-S3-318, IAC-S4-39 e IAC-SVS-1, com baixas porcentagens de infecção por TCSV, e notas de sintomas de TYVSV próximas à média de 'Franco', caracterizando-se como promissoras para obtenção de cultivares com resistência aos dois vírus.Thirteen lines and three commercial tomato cultivars were screened for tospovirus and geminivirus resistance under field conditions, in Campinas, São Paulo State, Brazil. The germplasm comprised advanced IAC lines plus cultivars Stevens, Franco and IPA-5. The same experiment was carried out in two planting seasons. In the first (December 2001 to February 2002, only Tomato chlorotic spot virus (TCSV occurred in the field. In the second (July to September 2002, Tomato yellow vein streak virus (TYVSV was identified in the experimental area, and the evaluation was carried out through counting of infected

  19. Palaearctic-African Bird Migration

    DEFF Research Database (Denmark)

    Iwajomo, Soladoye Babatola

    Bird migration has attracted a lot of interests over past centuries and the methods used for studying this phenomenon has greatly improved in terms of availability, dimension, scale and precision. In spite of the advancements, relatively more is known about the spring migration of trans......-Saharan migrants than autumn migration. Information about the behavior and interactions of migrants during the nonbreeding season in sub-Saharan Africa is also scarce for many species. Furthermore, very little is known about intra-African migration. This thesis summarizes my research on the autumn migration...... of birds from Europe to Africa and opens up the possibility of studying intra-African migration. I have used long-term, standardized autumn ringing data from southeast Sweden to investigate patterns in biometrics, phenology and population trends as inferred from annual trapping totals. In addition, I...

  20. South African Music Studies

    African Journals Online (AJOL)

    SAMUS: South African Music Studies is the official organ for the South African Society for Research in Music (SASRIM). It gives priority to the publication of research on South African music, but continues to represent the wider field of research interests in the country and in the rest of Africa. The journal invites work from any ...

  1. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically ... African Research Review; The Roles of Information Communication Technologies in Education: Review Article with Emphasis to the Computer and Internet Ethiopian Journal ...

  2. African Journals Online: Zimbabwe

    African Journals Online (AJOL)

    Items 1 - 12 of 12 ... African Journal of Social Work. The African Journal of Social Work is an international refereed journal that serves as a forum for exchanging ideas and knowledge and discussing issues relevant to social work practice, education and research in the African region. Producing 2 issues a year, the Journal is ...

  3. African Anthropologist: Submissions

    African Journals Online (AJOL)

    Author Guidelines. The African Anthropologist is a biannual journal of the Pan African Anthropological Association. It provides a forum for African and Africanist anthropologists to publish articles, research reports, review articles, and book reviews. The views expressed in any published material are those of the authors and ...

  4. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically ... Nnamdi Azikiwe University Journal of International Law and Jurisprudence; The Fulani Jihad and its Implication for National Integration and Development in Nigeria African ...

  5. African Journal of Urology

    African Journals Online (AJOL)

    The African Journal of Urology is the official journal of the Pan African Urological Surgeons' Association (PAUSA) The journal is a bilingual publication - publishing articles in English and French. The African Journal of Urology covers the whole scope of urology as well as the related basic sciences. In allignment with the ...

  6. Linguistic Imperialism: African Perspectives.

    Science.gov (United States)

    Phillipson, Robert

    1996-01-01

    Responds to an article on aspects of African language policy and discusses the following issues: multilingualism and monolingualism, proposed changes in language policy from the Organization for African Unity and South African initiatives, the language of literature, bilingual education, and whose interests English-language teaching is serving.…

  7. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Madagascar Conservation & Development. Vol 11, No 3 (2017). South African Journal of Child Health. Vol 16, No 1 (2017). Agro-Science. Early View (Wetlands Special Issue). Madagascar Conservation & Development. Vol 9, No 4 (2017). African Journal of Health Professions Education. AJOL African Journals Online.

  8. African Journals Online (AJOL)

    African Journals Online (AJOL)

    South African Journal for Research in Sport, Physical Education and Recreation. Vol 17, No 4 (2017). African Health Sciences. Vol 6, No 1 (2015). Nigeria Journal of Pure and Applied Physics. Vol 5, No 2 (2017). Journal of Student Affairs in Africa. Vol 14, No 1 (2017). Annals of African Surgery. Vol 63, No 7-9 (2018).

  9. African Journals Online (AJOL)

    African Journals Online (AJOL)

    West African Journal of Applied Ecology. Vol 6, No 2 (2017). Filosofia Theoretica: Journal of African Philosophy, Culture and Religions. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been difficult for African researchers to access the work of other African academics. In partnership with ...

  11. Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

    Directory of Open Access Journals (Sweden)

    John E Pool

    Full Text Available Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia, while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa F(ST were found to be enriched in genomic regions of locally

  12. Population Genomics of Sub-Saharan Drosophila melanogaster: African Diversity and Non-African Admixture

    Science.gov (United States)

    Pool, John E.; Corbett-Detig, Russell B.; Sugino, Ryuichi P.; Stevens, Kristian A.; Cardeno, Charis M.; Crepeau, Marc W.; Duchen, Pablo; Emerson, J. J.; Saelao, Perot; Begun, David J.; Langley, Charles H.

    2012-01-01

    Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia), while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa FST were found to be enriched in genomic regions of locally elevated cosmopolitan

  13. Geographically widespread mitochondrial lineages of the African ...

    African Journals Online (AJOL)

    The African saw-wings (genus Psalidoprocne) are a group of swallows endemic to sub-Saharan Africa. Although currently described as five species with several subspecies, the taxonomy of the saw-wings is unclear. We sequenced two mitochondrial genes (ND2 and cytb; 1 717 sites) from 20 individuals in order to ...

  14. African Zoology - Vol 15, No 1 (1980)

    African Journals Online (AJOL)

    Comparative morphology of the digestive system of 19 species of Southern African myomorph rodents in relation to diet and evolution · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. M.R. Perrin, B.A. Curtis, 22-33 ...

  15. Revision of the African genus Annickia (Annonaceae)

    NARCIS (Netherlands)

    Versteegh, C.P.C.; Sosef, M.S.M.

    2007-01-01

    complete revision, including a key to the species, drawings and distribution maps, of the tropical African Annonaceae genus Annickia (= Enantia Oliv., non Falc.) is presented. The exact phylogenetic position of this genus within the family has long been, and in fact still is, unclear. The status of

  16. Marketing African Leafy Vegetables: Challenges and Opportunities ...

    African Journals Online (AJOL)

    Activities to scale up production and consumption of African leafy vegetables have increased greatly in the recent past. What are the emerging issues in relationship to commercialization of these vegetables, given their previous unexploited state? The market share of ALVs vis-à-vis other vegetable species, particularly kales ...

  17. African Zoology - Vol 16, No 1 (1981)

    African Journals Online (AJOL)

    Some aspects of thermoregulation in three species of southern African tortoise · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL ... Feeding behaviour of sable Hippotragus niger niger (Harris, 1838) in the Rhodes Matopos National Park, Zimbabwe · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

  18. South African Journal of Animal Science

    African Journals Online (AJOL)

    The South African Journal of Animal Science is a peer-reviewed journal for publication of original scientific research articles and reviews in the field of animal science. The journal is published both electronically and in paper format. The scope of the journal includes reports of research dealing with farm livestock species ...

  19. Forests, people and environment: some African perspectives ...

    African Journals Online (AJOL)

    Furthermore, opportunities for using forests to mitigate climate change are highlighted with a case study on the economics associated with carbon markets. The issue also highlights the methodological challenges of quantifying carbon in African forests. The effect of climate change on threatened forest species and ...

  20. Sequence and recombination analyses of the geminivirus ...

    Indian Academy of Sciences (India)

    2006-09-18

    Sep 18, 2006 ... Author Affiliations. T Vadivukarasi1 K R Girish2 R Usha2. 1Center for Excellence in Bioinformatics, Madurai Kamaraj University, Madurai 625 021, India; Department of Plant Biotechnology, School of Biotechnology, Madurai Kamaraj University, Madurai 625 021, India ...

  1. african solutions to africa's problems? african approaches to peace ...

    African Journals Online (AJOL)

    Ilse van der Walt

    few Africans participated in the Pan-African congresses until the fifth one, held in. Manchester in 1945, where approximately one third of the delegates were African descendants. The first conference of the (then eight) independent African states was held in 1958 in Accra, Ghana. The Pan-African movement also enjoyed ...

  2. Local plant names reveal that enslaved Africans recognized substantial parts of the New World flora

    NARCIS (Netherlands)

    Andel, van T.R.; Klooster, van 't E.A.; Quiroz Villarreal, D.K.; Towns, A.M.; Ruysschaert, S.; Berg, van den M.

    2014-01-01

    How did the forced migration of nearly 11 million enslaved Africans to the Americas influence their knowledge of plants? Vernacular plant names give insight into the process of species recognition, acquisition of new knowledge, and replacement of African species with American ones. This study traces

  3. Endangered Species

    Science.gov (United States)

    EPA's Endangered Species Protection Program helps promote recovery of listed species. The ESPP determines if pesticide use in a geographic area may affect any listed species. Find needed limits on pesticide use in Endangered Species Protection Bulletins.

  4. Environmental ethics: An African understanding | Ojomo | African ...

    African Journals Online (AJOL)

    African Journal of Environmental Science and Technology. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 8 (2011) >. Log in or Register to get access to full text downloads.

  5. Bounding species distribution models

    Directory of Open Access Journals (Sweden)

    Thomas J. STOHLGREN, Catherine S. JARNEVICH, Wayne E. ESAIAS,Jeffrey T. MORISETTE

    2011-10-01

    Full Text Available Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for “clamping” model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART and maximum entropy (Maxent models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5: 642–647, 2011].

  6. Bounding Species Distribution Models

    Science.gov (United States)

    Stohlgren, Thomas J.; Jarnevich, Cahterine S.; Morisette, Jeffrey T.; Esaias, Wayne E.

    2011-01-01

    Species distribution models are increasing in popularity for mapping suitable habitat for species of management concern. Many investigators now recognize that extrapolations of these models with geographic information systems (GIS) might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for "clamping" model extrapolations. We relied on two commonly used modeling approaches: classification and regression tree (CART) and maximum entropy (Maxent) models, and we tested a simple alteration of the model extrapolations, bounding extrapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suitable habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 (5): 642-647, 2011].

  7. An estimate of the number of tropical tree species

    DEFF Research Database (Denmark)

    Slik, J. W Ferry; Arroyo-Rodríguez, Víctor; Aiba, Shin Ichiro

    2015-01-01

    to be as species-rich as the Neotropics, with both regions having a minimum of ∼19,000-25,000 tree species. Continental Africa is relatively depauperate with a minimum of ∼4,500-6,000 tree species. Very few species are shared among the African, American, and the Indo-Pacific regions. We provide a methodological...

  8. New species of Maerua (Capparaceae) from Angola

    NARCIS (Netherlands)

    Abreu, J.A.; Martins, E.S.; Catarino, L.

    2014-01-01

    Genus Maerua has around 60 species represented on the African continent, of which three have been reported for Angola. Two new species of Maerua (Capparaceae) from Angola are here described. Both are closely similar to M. juncea subsp. juncea, being distinguished by floral traits such as the

  9. Infant Mortality and African Americans

    Science.gov (United States)

    ... Profiles > Black/African American > Infant Health & Mortality Infant Mortality and African Americans African Americans have 2.2 ... to receive late or no prenatal care. Infant Mortality Rate Infant mortality rate per 1,000 live ...

  10. Genetic diversity of bitter and sweet African bush mango trees ...

    African Journals Online (AJOL)

    Economically important food tree species in sub-Saharan Africa should be domesticated to enhance their production within agro forestry systems. The African bush mango trees (Irvingia species) are highly preserved and integrated in agro forestry systems in tropical Africa. However, the taxonomic debate related to the ...

  11. Changes to the scientific and common names of southern African ...

    African Journals Online (AJOL)

    Additions and changes to the scientific and common names of southern African freshwater fishes made since 1993, are recorded and explained. Nineteen new scientific names are listed including five new species, three genus-name changes, three species-name changes and four new records from the area.

  12. Patterns of endemicity and range restriction among southern African ...

    African Journals Online (AJOL)

    Patterns of endemicity and range restriction among southern African coastal marine invertebrates. RJ Scott, CL Griffiths, TB Robinson. Abstract. Southern Africa supports a rich marine biota of 12 734 currently described marine species. Although the distribution and overall species-richness patterns of several component ...

  13. In vitro cytotoxicity of crude alkaloidal extracts of South African ...

    African Journals Online (AJOL)

    The cytotoxicity of crude alkaloid extracts obtained from the leaves and rhizomes of all the South African members of the family Menispermaceae (seven genera and 13 species) was tested against MCF7 (breast), UACC62 (melanoma) and TK10 (renal) cancer cell lines. Extracts of ten of the thirteen species showed positive ...

  14. The African Union's notion of 'African solutions to African problems ...

    African Journals Online (AJOL)

    intervention of the UN and France in Côte d'Ivoire; and the North Atlantic ... 2 Before NATO intervened as an organisation, its individual members including France, .... states. A culture of impunity and indifference was cultivated and became entrenched in the international relations of the African countries. Thus, learning.

  15. African agricultural trade

    DEFF Research Database (Denmark)

    Jensen, Hans Grinsted; Sandrey, Ron

    2015-01-01

    This article starts with a profile of African agricultural trade. Using the pre-release version 9.2 of the GTAP database, we then show that the results for tariff elimination on intra-African trade are promising, but these tariff barriers are not as significant as the various trade-related barriers...

  16. African Journals Online: Armenia

    African Journals Online (AJOL)

    African Journals Online: Armenia. Home > African Journals Online: Armenia. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  17. African Journals Online: Switzerland

    African Journals Online (AJOL)

    African Journals Online: Switzerland. Home > African Journals Online: Switzerland. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  18. African Journals Online (AJOL)

    African Journals Online (AJOL)

    The abnormal chest X-ray – when to refer to a specialist. Continuing Medical ... South African Journal of Education; The functions of school governing bodies in managing school finances. South African Journal ... EJOTMAS: Ekpoma Journal of Theatre and Media Arts; Clinical approach to the floppy child. Continuing Medical ...

  19. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly information ... Ethiopian Journal of Education and Sciences; Advertising practice in Nigeria: Development, new trends, challenges and prospects. EJOTMAS: Ekpoma ...

  20. African Journals Online: Andorra

    African Journals Online (AJOL)

    African Journals Online: Andorra. Home > African Journals Online: Andorra. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  1. African Journals Online: Bahamas

    African Journals Online (AJOL)

    African Journals Online: Bahamas. Home > African Journals Online: Bahamas. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  2. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Mizan Law Review; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? ... African Journal of Biotechnology; The application of just administrative action in the South African environmental governance sphere: An analysis of some ...

  3. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Continuing Medical Education; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of ... African Journal of Biotechnology; The application of just administrative action in the South African environmental governance sphere: An analysis of some ...

  4. African Journals Online: Kiribati

    African Journals Online (AJOL)

    African Journals Online: Kiribati. Home > African Journals Online: Kiribati. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  5. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly information has ... Africa Development; Advertising practice in Nigeria: Development, new trends, challenges and prospects. EJOTMAS: Ekpoma Journal of Theatre ...

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly ... Arab Journal of Nephrology and Transplantation; Advertising practice in Nigeria: Development, new trends, challenges and prospects. EJOTMAS: Ekpoma Journal ...

  7. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly ... AFRREV IJAH: An International Journal of Arts and Humanities; Advertising practice in Nigeria: Development, new trends, challenges and prospects. EJOTMAS: ...

  8. African Journals Online (AJOL)

    African Journals Online (AJOL)

    South African Journal of Clinical Nutrition. Vol 22, No 3 (2017). Journal of Endocrinology, Metabolism and Diabetes of South Africa. Vol 38, No 1 (2017). Nigerian Veterinary Journal. Vol 28, No 2 (2017). Legon Journal of the Humanities. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians ...

  9. African Journals Online (AJOL)

    African Journals Online (AJOL)

    South African Journal of Clinical Nutrition. Vol 22, No 3 (2017). Journal of Endocrinology, Metabolism and Diabetes of South Africa. Vol 38, No 1 (2017). Nigerian Veterinary Journal. Vol 28, No 2 (2017). Legon Journal of the Humanities. Vol 19, No 2 (2017). Nigerian Journal of Animal Science. AJOL African Journals Online.

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    South African Journal of Clinical Nutrition. Vol 22, No 3 (2017). Journal of Endocrinology, Metabolism and Diabetes of South Africa. Vol 38, No 1 (2017). Nigerian Veterinary Journal. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners ...

  11. African Journals Online: Uganda

    African Journals Online (AJOL)

    Items 1 - 12 of 12 ... African Crop Science Journal. The African Crop Science Journal, a quarterly publication, publishes original research papers dealing with all aspects of crop agronomy, production, genetics and breeding, germplasm, crop protection, post harvest systems and utilisation, agro-forestry, crop-animal interactions ...

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. ... Featured Country: Nigeria, Featured Journal: Journal of Educational Foundations ... Journal of Agriculture and Social Research (JASR).

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. ... AFRREV IJAH: An International Journal of Arts and Humanities; Human Rights under the Ethiopian Constitution: A Descriptive Overview

  14. Annals of African Surgery

    African Journals Online (AJOL)

    The goal of the Annals of African Surgery is to provide a medium for the exchange of current information between surgeons in the African region. The journal embraces surgery in all its aspects; basic science, clinical research, experimental research, surgical education. It will assist surgeons in the region to keep abreast of ...

  15. African Journals Online: Vanuatu

    African Journals Online (AJOL)

    African Journals Online: Vanuatu. Home > African Journals Online: Vanuatu. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  16. African Journals Online: Grenada

    African Journals Online (AJOL)

    African Journals Online: Grenada. Home > African Journals Online: Grenada. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  17. African Journals Online: Barbados

    African Journals Online (AJOL)

    African Journals Online: Barbados. Home > African Journals Online: Barbados. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  18. African Journals Online: India

    African Journals Online (AJOL)

    African Journals Online: India. Home > African Journals Online: India. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  19. African American Suicide

    Science.gov (United States)

    African American Suicide Fact Sheet Based on 2012 Data (2014) Overview • In 2012, 2,357 African Americans completed suicide in the U.S. Of these, 1,908 (80. ... rate of 9.23 per 100,000). The suicide rate for females was 1.99 per 100, ...

  20. African Journals Online: Malta

    African Journals Online (AJOL)

    African Journals Online: Malta. Home > African Journals Online: Malta. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  1. African Journals Online: Guernsey

    African Journals Online (AJOL)

    African Journals Online: Guernsey. Home > African Journals Online: Guernsey. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  2. African Journals Online: Liechtenstein

    African Journals Online (AJOL)

    African Journals Online: Liechtenstein. Home > African Journals Online: Liechtenstein. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  3. African Journals Online: Belgium

    African Journals Online (AJOL)

    African Journals Online: Belgium. Home > African Journals Online: Belgium. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  4. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. AJOL is a Non-Profit Organisation based ... International Journal of Engineering, Science and Technology. Vol 30, No 1 (2018): Volume 30 ...

  5. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. AJOL is a Non-Profit Organisation based ... International Journal of Engineering, Science and Technology. Vol 4, No 1 (2012). International ...

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to the rest of the world. AJOL is a Non-Profit Organisation ... Featured Country: Nigeria, Featured Journal: Journal of Applied Science, Engineering and Technology ...

  7. African Journals Online: Aruba

    African Journals Online (AJOL)

    African Journals Online: Aruba. Home > African Journals Online: Aruba. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  8. African Journals Online: Kazakhstan

    African Journals Online (AJOL)

    African Journals Online: Kazakhstan. Home > African Journals Online: Kazakhstan. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access ...

  9. African Literature as Celebration.

    Science.gov (United States)

    Achebe, Chinua

    1989-01-01

    Describes the Igbo tradition of "Mbari," a communal creative enterprise that celebrates the world and the life lived in it through art. Contrasts the cooperative, social dimension of pre-colonial African culture with the exclusion and denial of European colonialism, and sees new African literature again celebrating human presence and…

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Featured Country: South Africa, Featured Journal: Journal for Juridical Science ... The Roles of Information Communication Technologies in Education: Review Article with Emphasis to the Computer and Internet Ethiopian ... South African Journal of Education; Methods of Conflict Resolution in African Traditional Society

  11. African Journals Online: Nigeria

    African Journals Online (AJOL)

    Items 1 - 50 of 221 ... African Journal of Library, Archives and Information Science is established mainly to provide a forum for librarians, archivists, documentalists, information scientists and other information related professionals in Africa to report their research findings but with emphasis on African setting. The Journal is ...

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Continuing Medical Education; Educational leadership and management: theory, policy and practice. South African Journal of Education; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; The ...

  13. African Zoology: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. African Zoology, a peer-reviewed research journal, publishes original scientific contributions and critical reviews that focus principally on African fauna in terrestrial, freshwater, and marine ecosystems. Research from other regions that advances practical and theoretical aspects of zoology will be ...

  14. East African Medical Journal

    African Journals Online (AJOL)

    Journal Homepage Image. The East African Medical Journal is intended for publication of papers on original work and reviews of all aspects of medicine. Communications bearing on clinical and basic research on problems relevant to East Africa and other African countries will receive special attention. The EAMJ has a 3 ...

  15. African Journals Online: Mozambique

    African Journals Online (AJOL)

    African Journal of Governance and Development. The African Journal of Governance and Development is a multidisciplinary publication that seeks to bring academic researchers from beyond territorial and regional boundaries to share scientific knowledge focused on the interface of governance and development.

  16. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Bulletin of Animal Health and Production in Africa. Vol 22, No 2 (2017). East and Central African Journal of Surgery. Vol 6, No 1 (2018). International Journal of Pedagogy, Policy and ICT in Education. Vol 64, No 3 (2016). Bulletin of Animal Health and Production in Africa. Vol 26, No 1 (2018). African Crop Science Journal.

  17. African Journals Online (AJOL)

    African Journals Online (AJOL)

    In partnership with hundreds of journals from all over the continent, AJOL works to change this, so that African-origin research output is available to Africans and to ... Ergonomics SA. Vol 9, No 1 (2017). Inkanyiso: Journal of Humanities and Social Sciences. Vol 14, No 5 (2017). Journal of Pharmaceutical and Allied Sciences.

  18. Keeping African Masks Real

    Science.gov (United States)

    Waddington, Susan

    2012-01-01

    Art is a good place to learn about our multicultural planet, and African masks are prized throughout the world as powerfully expressive artistic images. Unfortunately, multicultural education, especially for young children, can perpetuate stereotypes. Masks taken out of context lose their meaning and the term "African masks" suggests that there is…

  19. African Art Teaching Strategies.

    Science.gov (United States)

    Chanda, Jacqueline

    Three different models for the teaching of African art are presented in this paper. A comparison of the differences between the approaches of Western art historians and African art historians informs the articulation of the three models--an approach for determining style, another for dealing with analysis, and a third for synthetic interpretation.…

  20. Inspired by African Art.

    Science.gov (United States)

    Heintz, June Rutledge

    1991-01-01

    Argues that African art helps children to learn vital art concepts and enlarges their understanding of the role of art in human culture. Outlines a unit on African art based on animals. Students created fabric designs and illustrated folktales and fables. Provides a list of free resources. (KM)

  1. Archives: African Health Sciences

    African Journals Online (AJOL)

    Items 1 - 50 of 67 ... Archives: African Health Sciences. Journal Home > Archives: African Health Sciences. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 50 of 67 Items, 1 2 > >> ...

  2. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Ethiopian Journal of Education and Sciences; Conflicts in Africa: Meaning, Causes, Impact and Solution African Research Review; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; The Rise of ...

  3. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Legon Journal of the Humanities. Vol 19, No 2 (2017). Nigerian Journal of Animal Science. Vol 36, No 1 (2017). African Journal of Neurological Sciences. Vol 86, No 2 (2017). Tanzania Journal of Forestry and Nature Conservation. Vol 37, No 4 (2016). Nigerian Veterinary Journal. Vol 33 (2017). Southern African Journal of ...

  4. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journals OnLine (AJOL) is the world's largest and pre-eminent collection of peer-reviewed, African-published scholarly journals. Historically, scholarly information has flowed ... Thought and Practice; Advertising practice in Nigeria: Development, new trends, challenges and prospects. EJOTMAS: Ekpoma Journal of ...

  5. African Health Sciences

    African Journals Online (AJOL)

    African Health Sciences is an open access, free online, internationally refereed journal publishing original articles on research, clinical practice, public health, policy, planning, implementation and evaluation, in the health and related sciences relevant to Africa and the tropics. African Health Sciences acknowledges support ...

  6. African Journals Online (AJOL)

    African Journals Online (AJOL)

    It has also been difficult for African researchers to access the work of other African academics. In partnership with ... AJOL hosts 521 Journals, including 224 Open Access Journals; The site has 12 752 Issues containing 149 326 Abstracts. There are 143 542 Full ... Marang: Journal of Language and Literature. Vol 28, No 1 ...

  7. Annals of African Medicine

    African Journals Online (AJOL)

    The Annals of African Medicine is published by the Usmanu Danfodiyo University Teaching Hospital, Sokoto, Nigeria and the Annals of African Medicine Society. The Journal is intended to serve as a medium for the publication of research findings in the broad field of Medicine in Africa and other developing countries, and ...

  8. African Journals Online (AJOL)

    African Journals Online (AJOL)

    African Journal of Oral Health. Vol 35, No 1-2 (2017). Egyptian Journal of Biochemistry and Molecular Biology. Vol 7, No 3 (2017). African Journal of Chemical Education. Vol 8, No 2 (2017): Journal of Language, Technology & Entrepreneurship in Africa. Journal of Language, Technology & Entrepreneurship in Africa.

  9. African Journals Online: Ireland

    African Journals Online (AJOL)

    African Journals Online: Ireland. Home > African Journals Online: Ireland. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Browse By Category · Browse Alphabetically · Browse By Country · List All Titles · Free to read Titles This Journal is Open Access. Afghanistan ...

  10. Archives: African Studies Monographs

    African Journals Online (AJOL)

    Archives: African Studies Monographs. Journal Home > Archives: African Studies Monographs. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 5 of 5 Items. 2007. Vol 8 (2007) ...

  11. African Peacekeepers in Africa

    DEFF Research Database (Denmark)

    Emmanuel, Nikolas G.

    2015-01-01

    peacekeeping operations in the region. It is important to add that the international community has frequently tried to facilitate the deployment of African armed forces with aid and training. From this reality, the following study goes beyond the current literature by focusing on the international factors......African states today are strongly encouraged by the United States (US) and other members of the international community to play a more central role in confronting crises on the continent. Indeed, in recent years African armed forces have increasingly served as the backbone supporting various...... behind African participation in United Nations (UN) peacekeeping operations in Africa. In doing so, this research focuses on US military aid and foreign troop training from 2002 to 2012, and its impact on African deployments into UN peacekeeping missions in Africa. As can be expected, such third...

  12. Genome Sequences of Oryza Species

    KAUST Repository

    Kumagai, Masahiko

    2018-02-14

    This chapter summarizes recent data obtained from genome sequencing, annotation projects, and studies on the genome diversity of Oryza sativa and related Oryza species. O. sativa, commonly known as Asian rice, is the first monocot species whose complete genome sequence was deciphered based on physical mapping by an international collaborative effort. This genome, along with its accurate and comprehensive annotation, has become an indispensable foundation for crop genomics and breeding. With the development of innovative sequencing technologies, genomic studies of O. sativa have dramatically increased; in particular, a large number of cultivars and wild accessions have been sequenced and compared with the reference rice genome. Since de novo genome sequencing has become cost-effective, the genome of African cultivated rice, O. glaberrima, has also been determined. Comparative genomic studies have highlighted the independent domestication processes of different rice species, but it also turned out that Asian and African rice share a common gene set that has experienced similar artificial selection. An international project aimed at constructing reference genomes and examining the genome diversity of wild Oryza species is currently underway, and the genomes of some species are publicly available. This project provides a platform for investigations such as the evolution, development, polyploidization, and improvement of crops. Studies on the genomic diversity of Oryza species, including wild species, should provide new insights to solve the problem of growing food demands in the face of rapid climatic changes.

  13. Human Rights and the African Renaissance | Acheampong | African ...

    African Journals Online (AJOL)

    This article examines the idea of African renaissance in relation to the teaching of human rights in African schools. It explores the connection between the African Renaissance and human rights, and whether there is a specific African concept of human rights. In the light of these discussions, the article sketches a perspective ...

  14. Towards an African cultural renaissance | Kanu | Sophia: An African ...

    African Journals Online (AJOL)

    ... as some groups hold. Also, it is not a call to close the door against cultural. This paper argues that for Africans to be Africans, they must know what makes them Africans with regard to their cultural heritage. This was the point stressed by Socrates when he said “Man know thyself”. Keywords: African, Culture, Renaissance ...

  15. Application of the African Charter by African Sub-Regional ...

    African Journals Online (AJOL)

    However, it is doubtful if even the most visionary of African leaders or the most optimistic of human rights advocates ever foresaw the adoption of the African Charter by other African international organisations. By 2007, the African Charter had become such a common feature in the founding instruments of some regional ...

  16. The African Diaspora in continental African struggles for freedom ...

    African Journals Online (AJOL)

    In light of this realization, this article discusses the contributions of the African Diaspora towards continental African liberation from European colonial domination, with a view to theorizing the implications of this history on the criticism of African Renaissance literature. Focusing on Diasporan African agency in organizing ...

  17. Four new species of Cichlidogyrus Paperna, 1960 (Monogenea, Ancyrocephalidae), all gill parasites from African mouthbreeder tilapias of the genera Sarotherodon and Oreochromis (Pisces, Cichlidae), with a redescription of C. thurstonae Ergens, 1981.

    Science.gov (United States)

    Pariselle, Antoine; Bilong Bilong, Charles F; Euzet, Louis

    2003-11-01

    A study of Oreochromis niloticus (Linnaeus), O. aureus (Steindachner), Sarotherodon caudomarginatus (Boulenger), S. galilaeus (Linnaeus) and S. galilaeus sanagaensis (Thys van den Audenaerde) (Teleostei, Cichlidae) from different locations in Africa (Burkina Faso, Cameroon, Guinea, Niger and Senegal) revealed the presence of 11 species of monogenean gill parasites. Four, belonging to Cichlidogyrus Paperna, 1960 and considered as new species, are described: C. rognoni n. sp., C. douellouae n. sp., C. giostrai n. sp. and C. njinei n. sp. They are distinguished by the shape and/or size of the sclerotised parts of the haptoral and copulatory complexes. C. thurstonae Ergens, 1981 from O. niloticus is redescribed.

  18. Ectomycorrhizal symbiosis of tropical African trees.

    Science.gov (United States)

    Bâ, Amadou M; Duponnois, Robin; Moyersoen, Bernard; Diédhiou, Abdala G

    2012-01-01

    The diversity, ecology and function of ectomycorrhizal (EM) fungi and ectomycorrhizas (ECMs) on tropical African tree species are reviewed here. While ECMs are the most frequent mycorrhizal type in temperate and boreal forests, they concern an economically and ecologically important minority of plants in African tropical forests. In these African tropical forests, ECMs are found mainly on caesalpionioid legumes, Sarcolaenaceae, Dipterocarpaceae, Asterpeiaceae, Phyllantaceae, Sapotaceae, Papilionoideae, Gnetaceae and Proteaceae, and distributed in open, gallery and rainforests of the Guineo-Congolian basin, Zambezian Miombo woodlands of East and South-Central Africa and Sudanian savannah woodlands of the sub-sahara. Overall, EM status was confirmed in 93 (26%) among 354 tree species belonging to EM genera. In addition, 195 fungal taxa were identified using morphological descriptions and sequencing of the ML5/ML6 fragment of sporocarps and ECMs from West Africa. Analyses of the belowground EM fungal communities mostly based on fungal internal transcribed spacer sequences of ECMs from Continental Africa, Madagascar and the Seychelles also revealed more than 350 putative species of EM fungi belonging mainly to 18 phylogenetic lineages. As in temperate forests, the /russula-lactarius and /tomentella-thelephora lineages dominated EM fungal flora in tropical Africa. A low level of host preference and dominance of multi-host fungal taxa on different African adult tree species and their seedlings were revealed, suggesting a potential for the formation of common ectomycorrhizal networks. Moreover, the EM inoculum potential in terms of types and density of propagules (spores, sclerotia, EM root fragments and fragments of mycelia strands) in the soil allowed opportunistic root colonisation as well as long-term survival in the soil during the dry season. These are important characteristics when choosing an EM fungus for field application. In this respect, Thelephoroid fungal sp

  19. African communalism and globalization | Etta | African Research ...

    African Journals Online (AJOL)

    In this connection, it is the belief of this work that the current wind of globalization that the world is embracing is of no much difference from African communalism. As such, this work suggests that each of the above should complement the other in harnessing developmental strides while pursuing the empowerment of the ...

  20. African communalism and globalization | Etta | African Research ...

    African Journals Online (AJOL)

    African Research Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 10, No 3 (2016) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Download this PDF file. The PDF file you selected should load ...

  1. Africans Consuming Hair, Africans Consumed by Hair

    African Journals Online (AJOL)

    Perhaps schooled by repeated encounters with the violence of dominant others or simply enlightened by the wisdom of centuries of intimate conversations across myriad divides and chasms, Africans have cultivated a collective gaze that sees beyond appearances in their everyday understanding and articulation of reality.

  2. Alternate hosts of African cassava mosaic virus and East African cassava mosaic Cameroon virus in Nigeria.

    Science.gov (United States)

    Alabi, Olufemi J; Ogbe, Francis O; Bandyopadhyay, Ranajit; Lava Kumar, P; Dixon, Alfred G O; Hughes, Jaqueline d'A; Naidu, Rayapati A

    2008-01-01

    Cassava mosaic disease (CMD) caused by African cassava mosaic virus (ACMV) and East African cassava mosaic Cameroon virus (EACMCV) is the major constraint to cassava production in Nigeria. Sequences of the DNA-A component of ACMV and EACMCV isolates from leguminous plant species (Senna occidentalis, Leucana leucocephala and Glycine max), castor oil plant (Ricinus communis), a weed host (Combretum confertum) and a wild species of cassava (Manihot glaziovii) were determined. All ACMV isolates from these hosts showed 96-98% nucleotide sequence identity with cassava isolates from West Africa. EACMCV was found only in four hosts (S. occidentalis, L. leucocephala, C. confertum, M. glaziovii), and sequences of these isolates showed 96-99% identity with cassava isolates from West Africa. These results provide definitive evidence for the natural occurrence of ACMV and EACMCV in plant species besides cassava.

  3. Structure and species composition of novel forests dominated by an introduced species in northcentral Puerto Rico

    Science.gov (United States)

    Oscar J. Abelleira Martinez; Mariela A. Rodríguez; Ivonne Rosario; Nataly Soto; Armando López; Ariel E. Lugo

    2010-01-01

    The African tulip tree, Spathodea campanulata Beauv., is an introduced species forming novel forest types in Puerto Rico. These forests develop naturally after deforestation, agricultural use and land abandonment, and there are many questions as to their ecological characteristics. We sampled structure and species composition of large, small, and juvenile trees (C10,...

  4. Nomenclatural adjustments in African plants 1

    Directory of Open Access Journals (Sweden)

    Peter Goldblatt

    2014-12-01

    Full Text Available Background: Ongoing systematic studies of the African flora necessitate periodic nomenclatural adjustments and corrections. Objectives: To effect requisite nomenclatural changes. Method: Relevant literature was surveyed and type material located and studied. Results: Nomenclatural corrections were published in Justicia L. (Acanthaceae, Babiana KerGawl. and Geissorhiza Ker Gawl. (Iridaceae and Zaluzianskya F.W.Schmidt (Scrophulariaceae. Conclusions: Firstly, a complete enumeration of all southern African species of Justicia was provided within the infrageneric classification for the genus accepted by Graham (1988 and later modified and expanded by Ensermu (1990 and Hedrén (1990. In this circumscription, Justicia includes such well-established segregates in an African context as Adhatoda Miller, Aulojusticia Lindau, Duvernoia E.Mey. ex Nees, Monechma Hochst. and Siphonoglossa Oersted.Both southern African species of Adhatoda were transferred to Justicia, as well as all of the southern African species of Monechma, with eight new combinations or replacement names provided. All species were placed to section within Justicia. Secondly, the type of Gladiolus nervosus Lam. (1788 was considered to be conspecific with Gladiolus strictus Aiton (1789 and is therefore the earliest available name for the species currently known as Babiana stricta (Aiton Ker Gawl. The new combination Babiana nervosa (Lam. Goldblatt & J.C.Manning was provided. Thirdly, Geissorhiza ornithogaloides has been regarded as a new species described by F.W. Klatt (1866 but the name should be treated as the combination G. ornithogaloides (Lichst. ex Roem. & Schult. Klatt, based on Ixia ornithogaloides Lichst. ex Roem. & Schult.(1817a. Examination of the type showed that it is conspecific with Geissorhiza marlothii R.C.Foster (1941 and it is therefore the valid name for the taxon treated as G. ornithogaloides subsp. marlothii (R.C.Foster Goldblatt. An epitype for the taxon was designated

  5. A new species of Paropsia (Passifloraceae) from Gabon

    NARCIS (Netherlands)

    Breteler, F.J.

    2003-01-01

    Paropsia is an Old World genus of eleven species, one in Asia and ten in Africa, including four on the mainland and six in Madagascar (SLEUMER 1970). Of the four mainland species three occur in Central Africa (SLEUMER & BAMPS 1976) and the fourth is East-African. The new species described here

  6. Skin mechanics and morphology of two species of Pachydactylus ...

    African Journals Online (AJOL)

    The southern African species Pachydactylus namaquensis is one of only a few mainland species of geckos that exhibits the escape strategy of regional integumentary loss. The skin morphology and mechanics of this species were compared to the same parameters in lhe sympatric congener P. bibronii. The tensile strength ...

  7. A Comparative Study of Species Diversity of Migrant Birds Between ...

    African Journals Online (AJOL)

    Of the 54 species, 20 were Intra-African migrants and 34 Palearctic winters including two globally threatened species; the European Turtle Dove Streptopelia turtur and Pallid Harrier Circus macrourus. Results showed that Protected wetlands had significantly higher species diversity (H' = 1.39) than Unprotected ones (H' ...

  8. Effects of scarcity, aesthetics and ecology on wildlife auction prices of large African mammals.

    Science.gov (United States)

    Dalerum, Fredrik; Miranda, María; Muñiz, Cristina; Rodríguez, Plácido

    2018-02-01

    For successful integration of biological conservation into economic markets, economic processes need to capture ecological values. South African wildlife ranching is a tourist-based activity that generates unique information on the economic value of wildlife species. We used public data from South African wildlife auctions to evaluate if annual prices 1991-2012 related to species characteristics associated with scarcity, aesthetics and ecology of South African carnivores and ungulates. While none of the species characteristics influenced carnivore prices, ungulate prices were related to characteristics associated with novelty and aesthetics, which relative importance had increased over time. We raise both ecological and economic concerns for this apparent focus. Our results also suggest a potential importance of non-species-related factors, such as market and buyer characteristics. We encourage further evaluation of the relative influences of species characteristics versus factors that are intrinsically linked to economic processes on price variations in South African wildlife.

  9. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has ... Medical Sciences. Vol 7, No 2 (2017). Research in Hospitality Management. Vol 7, No 1 (2018). AFRREV IJAH: An International Journal of Arts and Humanities.

  10. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly ... Featured Country: Nigeria, Featured Journal: Journal of Modeling, Design and Management of Engineering Systems ... Nigeria Journal of Pure and Applied Physics. Vol 5, No 2 ...

  11. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. ... Featured Country: Nigeria, Featured Journal: Journal of Research in Forestry, Wildlife and Environment. Most recent issues on AJOL: Vol 6, No 1 (2015). Nigeria Journal of Pure and Applied Physics.

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly ... Featured Country: Nigeria, Featured Journal: International Journal of Development and Management Review ... Nigeria Journal of Pure and Applied Physics. Vol 5, No 2 (2017).

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically ... Featured Country: Tanzania, Featured Journal: University of Dar es Salaam Library Journal. Most recent issues on AJOL: Vol 6, No 1 (2015). Nigeria Journal of Pure and Applied Physics.

  14. African Journals Online (AJOL)

    African Journals Online (AJOL)

    reviewed, African-published scholarly journals. Historically, scholarly information has flowed from North to South and from West to East. It has also been ... Featured Country: Nigeria, Featured Journal: Nigeria Journal of Pure and Applied Physics ...

  15. South African Medical Journal

    African Journals Online (AJOL)

    Paediatric burns in a rural South African district hospital · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Mickey Chopra, Helen Kettle, David Wilkinson, Susy Stirling ...

  16. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Potchefstroom Electronic Law Journal/Potchefstroomse Elektroniese Regsblad; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; Conflicts in Africa: Meaning, Causes, Impact and Solution

  17. Editorial | Nkwi | African Anthropologist

    African Journals Online (AJOL)

    African Anthropologist. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 19, No 1-2 (2012) >. Log in or Register to get access to full text downloads.

  18. African Journals Online (AJOL)

    African Journals Online (AJOL)

    2013). International Journal of Engineering, Science and Technology. Vol 5, No 3 (2013). International Journal of Engineering, Science and Technology. Vol 30, No 1 (2018). South African Journal of Sports Medicine. Vol 66 (2014). Vulture News.

  19. African Americans and Glaucoma

    Science.gov (United States)

    ... Americans are still unknown. However, research shows that African Americans are genetically more at risk for glaucoma, making early detection and treatment all the more important. In studies such as the Baltimore Eye Survey and the ...

  20. Southern African Business Review

    African Journals Online (AJOL)

    Southern African Business Review. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 20, No 1 (2016) >. Log in or Register to get access to full text downloads.

  1. Fossil records of Palaearctic Pisidium species in tropical Africa (Bivalvia, Sphaeriidae)

    NARCIS (Netherlands)

    Kuiper, J.G.J.

    2009-01-01

    A collection of fossil shells of the genus Pisidium sampled in late glacial fluvio-lacustrine deposits in the Rift Valley, Ethiopia, contains four species of Palaearctic origin and two (or perhaps three) African species.

  2. The African Credit Trap

    OpenAIRE

    Svetlana Andrianova; Badi H. Baltagi; Panicos O. Demetriades; David Fielding

    2010-01-01

    We put forward a plausible explanation of African financial underdevelopment in the form of a bad credit market equilibrium. Utilising an appropriately modified IO model of banking, we show that the root of the problem could be unchecked moral hazard (strategic loan defaults) or adverse selection (a lack of good projects). We provide empirical evidence from a large panel of African banks which suggests that loan defaults are a major factor inhibiting bank lending when the quality of regulatio...

  3. West African monsoon 2012

    OpenAIRE

    Cornforth, Rosalind J.

    2013-01-01

    Living up to its reputation as a highly variable climate system, the West African Monsoon (WAM) 2012 contrasted strikingly with the previous year. In 2011, the West African rainy season was delayed, patchy, and irregular. In 2012, whilst it was anomalously wet in many area, the Guinea coastal countries and some crucial agricultural regions remained very dry, persisting from the previous year. As a result, 2012 generated the third big food crisis to hit the region in the last seven years. The ...

  4. African Zoology: Site Map

    African Journals Online (AJOL)

    Journal Home · Journals · African Zoology · About · Log In · Register · Advanced Search · By Author · By Title. Issues. Current Issue · Archives · Open Journal Systems · Help. ISSN: 2224-073X. AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

  5. African Anglo American

    Energy Technology Data Exchange (ETDEWEB)

    Chadwick, J.

    1993-11-01

    The South-African based Anglo-American Corp. dominates the mining industries of South Africa and Botswana and is very important in Namibia, Zimbabwe and Zambia. Most recently it has started prospecting in Tanzania once again. This article discusses the corporation's interests in Africa, gold, copper, diamonds, platinum, nickel and coal, and its interest in South American copper and various African metal industries. 6 refs., 5 figs., 1 tab.

  6. Africanized Honey Bee

    OpenAIRE

    Hodgson, Erin W.; Stanley, Cory A.; Roe, Alan H.; Downey, Danielle

    2010-01-01

    African honey bees (Apis mellifera scutellata) are native to sub-Saharan Africa and were introduced in the Americas to improve honey production in the tropics. These African honey bees were accidentally released and began to interbreed with European honey bees (Apis mellifera ligustica), the most common subspecies used for pollination and honey production in the United States (Fig. 1). As a result, the hybrid offspring are called “Africanized” because of their shared characteristics. Africani...

  7. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

    Science.gov (United States)

    2011-01-01

    Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA) for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA) were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV), Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya) contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV) and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a) primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b) primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully. PMID:21812981

  8. Biotechnological approaches to determine the impact of viruses in the energy crop plant Jatropha curcas

    Directory of Open Access Journals (Sweden)

    Maghuly Fatemeh

    2011-08-01

    Full Text Available Abstract Background Geminiviruses infect a wide range of plant species including Jatropha and cassava both belonging to family Euphorbiaceae. Cassava is traditionally an important food crop in Sub - Saharan countries, while Jatropha is considered as valuable biofuel plant with great perspectives in the future. Results A total of 127 Jatropha samples from Ethiopia and Kenya and 124 cassava samples from Kenya were tested by Enzyme-Linked Immunosorbent Assay (ELISA for RNA viruses and polymerase chain reaction for geminiviruses. Jatropha samples from 4 different districts in Kenya and Ethiopia (analyzed by ELISA were negative for all three RNA viruses tested: Cassava brown streak virus (CBSV, Cassava common mosaic virus, Cucumber mosaic virus, Three cassava samples from Busia district (Kenya contained CBSV. Efforts to develop diagnostic approaches allowing reliable pathogen detection in Jatropha, involved the amplification and sequencing of the entire DNA A molecules of 40 Kenyan isolates belonging to African cassava mosaic virus (ACMV and East African cassava mosaic virus - Uganda. This information enabled the design of novel primers to address different questions: a primers amplifying longer sequences led to a phylogenetic tree of isolates, allowing some predictions on the evolutionary aspects of Begomoviruses in Jatrophia; b primers amplifying shorter sequences represent a reliable diagnostic tool. This is the first report of the two Begomoviruses in J. curcas. Two cassava samples were co - infected with cassava mosaic geminivirus and CBSV. A Defective DNA A of ACMV was found for the first time in Jatropha. Conclusion Cassava geminiviruses occurring in Jatropha might be spread wider than anticipated. If not taken care of, this virus infection might negatively impact large scale plantations for biofuel production. Being hosts for similar pathogens, the planting vicinity of the two crop plants needs to be handled carefully.

  9. African Fish Biodiversity, Fishbase and Fishculture

    Directory of Open Access Journals (Sweden)

    Boden, G.

    2004-01-01

    Full Text Available At present, about 28 600 fish species are considered valid, whilst the total number is estimated at 30 000 to 35 000. For Africa, about 3 000 valid fresh- and brackish water species are currently recognized. Conserving the biodiversity of these fishes and at the same time managing their exploitation in a sustainable way is a difficult exercise. In sub-Saharan Africa, the importance of aquaculture is not very high. Nonetheless, 18 different species are used commercially, of which six have a non-African origin. Documenting and characterizing the ichthyodiversity is vital for conservation and sustainable development purposes. The presence of a large collection, a specialised library and a considerable know-how in the Africa Museum has led to various revisions, checklists, species (redescriptions and regional guides. All the information on African fishes is currently being entered in FishBase, a huge freely accessible database with information on the taxonomy, ecology and various other aspects of the biology of fishes, based on scientific publications and reviewed by specialists. FishBase also includes high quality tools for applied research on fishes, such as a disease wizard, biogeography tools, trophic pyramids, and the species invasiveness tool.

  10. Invasive Species

    Science.gov (United States)

    Invasive species have significantly changed the Great Lakes ecosystem. An invasive species is a plant or animal that is not native to an ecosystem, and whose introduction is likely to cause economic, human health, or environmental damage.

  11. African American Diaspora

    Directory of Open Access Journals (Sweden)

    Angela Brown

    2013-05-01

    Full Text Available The migration of blacks in North America through slavery became united.  The population of blacks past downs a tradition of artist through art to native born citizens. The art tradition involved telling stories to each generation in black families. The black culture elevated by tradition created hope to determine their personal freedom to escape from poverty of enslavement and to establish a way of life through tradition. A way of personal freedoms was through getting a good education that lead to a better foundation and a better way of life. With regard to all historic migrations (forced and voluntary, the African Union defined the African diaspora as "[consisting] of people of African origin living outside the continent, irrespective of their citizenship and nationality and who are willing to contribute to the development of the continent and the building of the African Union." Its constitutive act declares that it shall "invite and encourage the full participation of the African diaspora as an important part of our continent, in the building of the African Union."

  12. Islands in a desert : breeding ecology of the African Reed Warbler Acrocephalus baeticatus in Namibia

    NARCIS (Netherlands)

    Eising, CM; Komdeur, J; Buys, J; Reemer, M; Richardson, DS; Richardson, David S.

    The continental African Reed Warbler Acrocephalus baeticatus, like its relative the Seychelles Warbler Acrocephalus sechellensis, breeds in isolated patches. We studied the mating system of the African Reed Warbler to see whether this species, like the Seychelles Warbler, shows co-operative

  13. African leafy vegetables in South Africa | Jan van Rensburg | Water SA

    African Journals Online (AJOL)

    In this article the term 'African leafy vegetables' was adopted to refer to the collective of plant species which are used as leafy vegetables and which are referred to as morogo or imifino by African people in South Africa. Function is central in this indigenous concept, which is subject to spatial and temporal variability in terms ...

  14. No evidence of African swine fever virus replication in hard ticks

    NARCIS (Netherlands)

    de Carvalho Ferreira, Helena C; Tudela Zúquete, Sara; Wijnveld, Michiel; Weesendorp, Eefke; Jongejan, Frans; Stegeman, Arjan; Loeffen, Willie L A

    African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in

  15. African rainforests: past, present and future.

    Science.gov (United States)

    Malhi, Yadvinder; Adu-Bredu, Stephen; Asare, Rebecca A; Lewis, Simon L; Mayaux, Philippe

    2013-01-01

    The rainforests are the great green heart of Africa, and present a unique combination of ecological, climatic and human interactions. In this synthesis paper, we review the past and present state processes of change in African rainforests, and explore the challenges and opportunities for maintaining a viable future for these biomes. We draw in particular on the insights and new analyses emerging from the Theme Issue on 'African rainforests: past, present and future' of Philosophical Transactions of the Royal Society B. A combination of features characterize the African rainforest biome, including a history of climate variation; forest expansion and retreat; a long history of human interaction with the biome; a relatively low plant species diversity but large tree biomass; a historically exceptionally high animal biomass that is now being severely hunted down; the dominance of selective logging; small-scale farming and bushmeat hunting as the major forms of direct human pressure; and, in Central Africa, the particular context of mineral- and oil-driven economies that have resulted in unusually low rates of deforestation and agricultural activity. We conclude by discussing how this combination of factors influences the prospects for African forests in the twenty-first century.

  16. African literature to-day

    Directory of Open Access Journals (Sweden)

    P. Sulzer

    1974-03-01

    Full Text Available Being interested in African literature one seems to swim from the very beginning in a terminological maelstrom. What is African literature? Is it literature written by any African author in any language? That would mean approaching the question from a purely racial basis. It would imply the art of demonstrating that any piece of such literature could infallibly be recognised as African, a thing which, as far as I know has never been done. Or is African literature strictly bound to traditional African culture?

  17. Preliminary data on the feeding habits of the endemic species Synodontis koensis Pellegrin, 1933 (Siluriformes, Mochokidae in a West African River (Sassandra River Basin, Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Yao S.S.

    2010-06-01

    Full Text Available In the implementation of programs for protection and management of ichthyofauna, endemic species should have high priority in the conservation measures. Their fishery should be based on intimate knowledge of their ecology and biology. Feeding habits of the endemic Mochokid Synodontis koensis were assessed in the Sassandra River (Côte d’Ivoire in relation to the study zone, the specimen sex and size, and the season. Of the 303 stomachs examined, 49 were empty (16%. The fluctuation of the vacuity index indicated that S. koensis feeds more at night. The diet consisted mainly of plant detritus and chironomid larvae. The statistical analysis of the feeding according to the study zones, the sex of fish and the seasons does not show any significant difference between regimes, whereas significant ontogenic shifts in diet were observed.

  18. Pollination Observations Of The African Violet In The Taita Hills, Kenya

    African Journals Online (AJOL)

    The African violet, Saintpaulia teitensis (Gesneriaceae), is an Eastern Arc global biodiversity hotspot endemic. Forest fragments on the Taita ... Pollinators of this endangered plant species were found to be exclusively wild bee species of the genus Amegilla (Apoidea: Aprocrita: Apidae). Four different species of Amegilla ...

  19. Towards an indigenous African bioethics | Behrens | South African ...

    African Journals Online (AJOL)

    One way is for African bioethicists to begin to apply indigenous African philosophy, thought and values to ethical issues. This project is important (i) to restore dignity; (ii) because a bioethics grounded in indigenous ideas is more likely to be accepted by Africans; and (iii) because such ideas can enrich bioethical discourse.

  20. Dupuytren's Diathesis in an African Male | Mbuva | Annals of African ...

    African Journals Online (AJOL)

    Dupuytren's disease is not common in the African population. Like in other populations early intervention before severe contractures is important in order to prevent recurrence. We present a case of a young African with Dupuytren's diathesis. Keywords: Dupuytren's, Diathesis, African, Surgery ...

  1. The Uniqueness of African Philosophy | Jaja | African Research ...

    African Journals Online (AJOL)

    In all facets of development, Africa and Africans have made tremendous contributions. Africans through their reflective attitudes to society, environment and nature have helped to add value to African societies and the world at large. This paper therefore, attempts at reflective activities (philosophy) thus adding value to our ...

  2. African Journals: An Evaluation of their Use in African Universities ...

    African Journals Online (AJOL)

    The use of African published journals in two African universities was surveyed through the use of questionnaire, interviews, journal usage count and citation analysis. The survey reveals that African published journals are not popular with academics because of lack of bibliographic and physical access. For conclusion to be ...

  3. Mental Health and African Americans

    Science.gov (United States)

    ... Minority Population Profiles > Black/African American > Mental Health Mental Health and African Americans Poverty level affects mental health ... compared to 120% of non-Hispanic whites. 1 MENTAL HEALTH STATUS Serious psychological distress among adults 18 years ...

  4. African-Americans and Alzheimer's

    Science.gov (United States)

    ... Share Plus on Google Plus African-Americans and Alzheimer's alz.org | IHaveAlz Introduction 10 Warning Signs Brain ... African-Americans are at a higher risk for Alzheimer's disease. Many Americans dismiss the warning signs of ...

  5. African Americans and Multiple Sclerosis

    Science.gov (United States)

    ... Council: nationalMSsociety.org/African- AmericansandMS African Americans & Multiple Sclerosis GENER AL INFORMATION MS STOPS PEOPLE FROM MOVING. ... Judy, diagnosed in 1982 What is MS? Multiple sclerosis (MS), an unpredictable, often disabling disease of the ...

  6. African Studies Monographs: Editorial Policies

    African Journals Online (AJOL)

    Focus and Scope. The African Studies Monographs is a serial that promotes research and scholarship on the African perspective worldwide. This includes matters of philosophy, history, literature, arts and culture, environment, gender, politics, administration crisis management, etc.

  7. Leadership in the African context

    OpenAIRE

    M. Masango

    2002-01-01

    The Western world has always viewed the African continent as plagued by corruption; dictatorship; military coups; rebellious leaders; greediness; misuse of power; and incompetent, politically unstable leaders - in effect, suspicious leaders who undermine their own democracies. This paper analyzes African leadership and its impact by concentrating on three historical eras, namely; the African Religious era; the Christian era, and the era of Globalization. These affected African leadership. In ...

  8. African Cultural Astronomy

    CERN Document Server

    Holbrook, Jarita C; Medupe, R. Thebe; Current Archaeoastronomy and Ethnoastronomy research in Africa

    2008-01-01

    Astronomy is the science of studying the sky using telescopes and light collectors such as photographic plates or CCD detectors. However, people have always studied the sky and continue to study the sky without the aid of instruments this is the realm of cultural astronomy. This is the first scholarly collection of articles focused on the cultural astronomy of Africans. It weaves together astronomy, anthropology, and Africa. The volume includes African myths and legends about the sky, alignments to celestial bodies found at archaeological sites and at places of worship, rock art with celestial imagery, and scientific thinking revealed in local astronomy traditions including ethnomathematics and the creation of calendars. Authors include astronomers Kim Malville, Johnson Urama, and Thebe Medupe; archaeologist Felix Chami, and geographer Michael Bonine, and many new authors. As an emerging subfield of cultural astronomy, African cultural astronomy researchers are focused on training students specifically for do...

  9. Among rodents and rhinos: interplay between small mammals and large herbivores in a South African savanna

    OpenAIRE

    Hagenah, N.

    2006-01-01

    Keywords:African savanna, biodiversity, Dichrostachys cinerea , different-sized herbivores, fire, herbivore interactions, murid rodents, spatial heterogeneityMankind has caused species extinction of many groups of organisms through the transformation and fragmentation of once continuous natural habitats. In order to protect and restore natural biodiversity hotspots such as the African savannas we need to understand the determinants of their community structure and species diversity. Evidence ...

  10. Parsing the Gulf between Africans and African Americans

    Directory of Open Access Journals (Sweden)

    Ashly Nsangou

    2018-02-01

    Full Text Available The rise in African immigrants to the US provides an opportunity to assess relations between Africans and African Americans in college. An online survey of 322 current and recently-graduated college students (including 45 Africans, 160 African Americans, and 117 whites assessed respondents’ experiences of racism in US high schools and colleges. Semi-structured interviews of 30 students (10 African, 10 African American and 10 white students supplemented these data. Even within a sociopolitical context of more visible racial intolerance, Black intra-racial cohesion was absent. Although more first- and second-generation Africans (73% felt that they had been judged while living in the US compared to African Americans (34% or whites (20%, for 70–80% of respondents, this had occurred only in high school. Despite experiencing these judgments, Africans’ identity related more to their focus on education than their race, reflected in a higher proportion who felt intense family pressure to attend college (65% compared to African Americans (37% and whites (39%. Interview data confirmed previous reports in the literature that African Americans lack a sense of connection to Africans, attributed to Africans’ purported sense of superiority and disregard for African Americans’ ongoing struggle to end oppression. These mixed-methods data suggest that intermingling in the college environment has not resulted in first- and second-generation Africans and African Americans sharing a common in-group, race-based identity. We discuss the implications of overlooking ethnic distinctions due to presumptions of racial homogeneity that deprive Black individuals of their uniqueness.

  11. Evaluating paratransgenesis as a potential control strategy for African trypanosomiasis.

    Science.gov (United States)

    Medlock, Jan; Atkins, Katherine E; Thomas, David N; Aksoy, Serap; Galvani, Alison P

    2013-01-01

    Genetic-modification strategies are currently being developed to reduce the transmission of vector-borne diseases, including African trypanosomiasis. For tsetse, the vector of African trypanosomiasis, a paratransgenic strategy is being considered: this approach involves modification of the commensal symbiotic bacteria Sodalis to express trypanosome-resistance-conferring products. Modified Sodalis can then be driven into the tsetse population by cytoplasmic incompatibility (CI) from Wolbachia bacteria. To evaluate the effectiveness of this paratransgenic strategy in controlling African trypanosomiasis, we developed a three-species mathematical model of trypanosomiasis transmission among tsetse, humans, and animal reservoir hosts. Using empirical estimates of CI parameters, we found that paratransgenic tsetse have the potential to eliminate trypanosomiasis, provided that any extra mortality caused by Wolbachia colonization is low, that the paratransgene is effective at protecting against trypanosome transmission, and that the target tsetse species comprises a large majority of the tsetse population in the release location.

  12. African Journals Online: Environmental Sciences

    African Journals Online (AJOL)

    Items 1 - 28 of 28 ... African Journal of Applied Zoology and Environmental Biology. The African Journal of Applied Zoology and Environmental Biology (formerly the African Journal of Applied Zoology) was inaugurated to meet the growing need for an indigenous authoritative organ for the dissemination of the results of ...

  13. English as an African Language.

    Science.gov (United States)

    Desai, Gaurav

    1993-01-01

    Discusses the role of the English language in postcolonial African literature, focusing on the politics of language, "Africanized" English, and the social languages used in Chinua Achebe's novels and concludes that English today is as much an African language as a British or American one. (Contains 37 references.) (MDM)

  14. African Journal of International Affairs

    African Journals Online (AJOL)

    The African Journal of International Affairs (AJIA) is a bi-annual publication of CODESRIA, Dakar, Senegal. It offers a platform for analyses on contemporary issues in African International Affairs in relation to global developments as they affect Africa. AJIA welcomes contributions in English and in French from both African ...

  15. The Struggles over African Languages

    Science.gov (United States)

    Maseko, Pam; Vale, Peter

    2016-01-01

    In this interview, African Language expert Pam Maseko speaks of her own background and her first encounter with culture outside of her mother tongue, isiXhosa. A statistical breakdown of South African languages is provided as background. She discusses Western (originally missionary) codification of African languages and suggests that this approach…

  16. African Journals Online: All Titles

    African Journals Online (AJOL)

    African Journal for the Psychological Study of Social Issues View Journal | Current Issue | Register. African ... African Journal of Educational Studies in Mathematics and Sciences View Journal | Current Issue | Register This .... Creative Artist: A Journal of Theatre and Media Studies View Journal | Current Issue | Register This ...

  17. West African Journal of Medicine

    African Journals Online (AJOL)

    The West African Journal of Medicine is owned by the West African College of Physicians and the West African College of Surgeons. Aims: The aims of the Journal are: To provide a medium for international dissemination of information about medical science in West Africa and elsewhere. To furnish a means whereby ...

  18. The African Union

    DEFF Research Database (Denmark)

    Mandrup, Thomas; Mandrup, Bjørn

    2009-01-01

    The African Union (AU) is a young international organisation, founded in 2002, which is still in the process of setting up its various institutions, while constantly having to face up to new challenges, such as civil wars breaking out and military coups being undertaken in its member states....... Moreover, the ‘African Security Architecture’, of which it is the central component, also includes sub-regional organisations to which responsibility is to be devolved for dealing with armed confl ict and other matters. These so-called Regional Economic Communities (RECs) are, likewise, constantly changing...

  19. Protection of the African Lion: A Critical Analysis of the Current International Legal Regime

    Directory of Open Access Journals (Sweden)

    Samantha Watts

    2016-04-01

    Full Text Available This article looks at the current international regime that pertains to the African lion, a species that needs adequate protection across its range (a range that does not adhere to state boundaries. This analysis comes at a time when threats such as habitat and prey loss, retaliatory killing, trophy hunting and trade, are all impacting the remaining populations of African lions. The species is in danger of rapid population decline and possible extinction in the near future. Two decades ago there was an abundance of African lions, roughly 100 000, on the continent. But at present there are less than 32 000, while some believe there to be as little as 15 000 left. This decline is mainly due to the threats noted above. African lions are currently listed as "vulnerable" on the International Union for Conservation of Nature Red List of Threatened Species. This listing is being contested by commentators who believe that the species now requires an "endangered" status. African lion populations, and the threats to the species, extend across state boundaries. Therefore, international law is of particular importance in providing conservation and protection measures to the species. Creating conservation obligations at a global level allows for more uniform action, implementation and enforcement of legislation at regional and local levels. Therefore this article looks at each threat to African lion populations in detail and then assesses the international legal regime pertaining to each of these threats, and whether that regime is adequate. The Convention on Biological Diversity, Convention on the Conservation of Migratory Species, Convention on International Trade in Endangered Species of Wild Fauna and Flora and the Convention on Wetlands of International Importance are but some of the international instruments that are analysed. This article outlines the arguments that the international legal framework is not acceptable for the protection of the species

  20. Hooded Vulture Necrosyrtes monachus and African White-backed ...

    African Journals Online (AJOL)

    Basic ecological information is still lacking for many species of African vultures. The Hooded Vulture Necrosyrtes monachus is known as a rare breeding resident in north-eastern South Africa. This study set out to monitor the nests of Hooded Vultures and, secondarily, White-backed Vultures Gyps africanus in the Olifants ...

  1. Population Dynamics of the Giant African River Prawn ...

    African Journals Online (AJOL)

    USER

    Growth, mortality, recruitment, yield-per-recruit and present rate of exploitation of the African river prawn Macrobrachium vollenhovenii were ... The present study is the first report on the population dynamics of the species in the Cross River Estuary,. Nigeria, and provides ..... Sea Demersal Fish Comm. 1979/G/24, 26 pp.

  2. Comparative Ecology Of The African Bony Tongue Fish Heterotis ...

    African Journals Online (AJOL)

    The ecology of sympatric African bony tongue fish, Heterotis niloticus and the catfish, Clarias gariepinus were compared during the dry and rainy conditions in the lower Oluwa River and its adjacent floodplains. Both species are common economic fish in Nigeria. There was no significant difference in the mean sizes of H.

  3. Diet composition and habitat use of the West African bushbuck ...

    African Journals Online (AJOL)

    Diet composition and habitat use of the West African bushbuck were investigated in three vegetation units (River, Riverine Forest, Woodland Savannah) along the Baoule River, during the first half of the dry season. Woody plants were the most frequently occurring species in faecal pellets and were thought to represent ...

  4. Redescription of the African duck leech Theromyzon cooperi ...

    African Journals Online (AJOL)

    The African duck leech Theromyzon cooperi, which is the only representative of the genus so far reported in Africa, is redescribed. Aspects of its internal morphology are described for the first time. The conspecificity of the two supposed species T. cooperi and T. lineatum is also indicated.

  5. Patterns of endemism in African birds: how much does taxonomy ...

    African Journals Online (AJOL)

    The primary database (in a one-degree geographical grid) served as a template for creating two new databases: one, where the distributional records were allocated to species according to the 'Speciation Atlases' for African birds (Hall and Moreau 1970, Snow 1978) and two, according to the finest taxonomic splitting that ...

  6. Zoogeography of the southern African echinoderm fauna | Thandar ...

    African Journals Online (AJOL)

    Over 400 species of echinoderms are currently known from southern African waters, south of the tropic of Capricorn. These comprise 17 crinoids, 99 asteroids, 124 ophiuroids, 59 echinoids and 108 holothuroids. The endemic component is the richest, accounting for at least 47% of the fauna, with the Indo-Pacific component, ...

  7. isiXhosa name for leopard | Feely | African Zoology

    African Journals Online (AJOL)

    The confusion among some speakers of isiXhosa concerning the meaning of ingwe can probably be traced to John Ayliff's dictionary of the language published in 1846. There he gives 'tiger' as ingwe and 'leopard' as ihlozi. He clearly treats the two as distinct species. This is contrary to South African usage in English and ...

  8. Identification, distribution and conservation status of the African ...

    African Journals Online (AJOL)

    The African golden cat Caracal aurata is Africa's least known felid. This paper describes how C. aurata can be most readily identified in the field and reviews what is known about this species' distribution and conservation status in Kenya. Forty-six records for C. aurata from 38 sites were compiled. The Mau Forest is the only ...

  9. Nitrogen utilisation and nitrient digestibility of west African dwarf ...

    African Journals Online (AJOL)

    An experiment to evaluate and compare the nitrogen utilization and nutrient digestibility of goat fed a pasture species (Cynodon nlemfuensis) or browse plant leaves (Spondias mombin or Gmelina arborea) based diets was conducted with fifteen (15) growing male West African Dwarf goats aged 7 – 7.5 months and ...

  10. Are caecilians rare? An East African perspective | Measey | Journal ...

    African Journals Online (AJOL)

    Despite increasing reports to the contrary, caecilians are often considered to be unusual components of tropical ecosystems, where they predate largely on soil ecosystem engineers. The status of two East African Boulengerula species is assessed using a quantitative randomised survey method and timed searches, ...

  11. Breeding biology of African grey parrot ( Psittacus erithacus ) in Kom ...

    African Journals Online (AJOL)

    Parrots are considered a globally threatened group but, despite that, little is known about the ecology and biology of many species in the wild, this is the case for African grey parrots (Psittacus erithacus). The aim of this work was to study the reproductive biology of the wild grey parrot and its involvement in the conservation ...

  12. Germination of important East African mountain forest trees ...

    African Journals Online (AJOL)

    Primary forest species mainly germinated under low illumination or dark conditions and showed a very short seed viability. The storage temperature did not influence viability, whereas the maturity of the seeds collected had a considerable influence on the germination success. Journal of East African Natural History Vol.

  13. Refined estimates of South African pelagic fish biomass from hydro ...

    African Journals Online (AJOL)

    The biomass of small pelagic fish species off the coast of South Africa has been monitored since 1984 using hydro-acoustic survey techniques. These time-series of spawner biomass and recruitment estimates form the basis for management of both the South African sardine Sardinops sagax and anchovy Engraulis ...

  14. Reproductive Performance Of West African Dwarf Sheep And Goats ...

    African Journals Online (AJOL)

    Reproductive performance or 20 pregnant ewes and 20 pregnant does of West African Dwarf breed at village level in Ogun State, Nigeria were compared in a study which lasted for 8 months. Litter size in ewes was 1.50 while that of does was 1.85. The number of males produced by the two species out-numbered that of ...

  15. Seasonality in fish assemblage structure in an East African ...

    African Journals Online (AJOL)

    Correspondence analysis indicated that seasonal fish assemblages were only distinct at the mouth of the creek with less clear seasonal structure in the upper region of the creek. Keywords: conservation, habitat functions, seasons, species abundance. African Journal of Marine Science 2013, 35(2): 163–173 ...

  16. Diet of nesting African Crowned Eagles Stephanoaetus coronatus in ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the species composition of prey caught in the forest, savanna and emerging habitats in which African Crowned Eagles Stephanoaetus coronatus breed in KwaZulu-Natal province, South Africa. At the 17 nest sites, the remains of 195 prey individuals were collected. The five dominant ...

  17. Mycology and spoilage of retail cashew nuts | Adebajo | African ...

    African Journals Online (AJOL)

    All the species recovered induced detectable loss in weights of the milled nuts, though to varying extents and would be expected to cause considerable spoilage of the nuts. Key words: Cashew nut, Anacardium occidentale, fungal count, mycology, Aspergillus sp., Penicillium sp., spoilage. African Journal of Biotechnology ...

  18. A Review Of Reproduction And Gamete Management In The African ...

    African Journals Online (AJOL)

    Information on the current status of reproduction and gamete management of the African Catfish, Clarias gariepinus (Burchell) a highly appreciated culturable fish species in Nigeria were reviewed. Natural and ... In nature, C. gariepinus has a discontinuous reproductive cycle regulated by cyclically active gonad tropes.

  19. Apical Shell Sculpture of some African Freshwater Limpets ...

    African Journals Online (AJOL)

    A Scanning Electron Microscope has been used to describe in detail the apical shell sculpture of sevenAfrican species (three genera) of freshwater limpet snails (Ancylidae). The apical sculpture of Ancylus fluviatilis (? syn. strigatus and ? brondeli) is striate, but quite different in basic pattern from the other three striate ...

  20. South African Journal of Animal Science: Editorial Policies

    African Journals Online (AJOL)

    The South African Journal of Animal Science is a peer-reviewed journal for publication of original scientific articles and reviews in the field of animal science. The scope of the journal includes reports of research dealing with farm livestock species (cattle, sheep, goats, pigs, horses, poultry and ostriches), as well as pertinent ...

  1. Haemolymph Biochemical Parameters of the African Giant Snail ...

    African Journals Online (AJOL)

    ++, Cu++ and Zn++ levels were higher (P<0.05) in the haemolymph of the African giant snail than in that of the big black snail. The uses and implications of these data in the management of these two wild snail species for meat and research are ...

  2. Breeding success of African penguins Spheniscus demersus at ...

    African Journals Online (AJOL)

    The reproductive success of African penguins Spheniscus demersus at Dassen Island from 1994 to 2000 was variable, but much higher than previously reported figures for the species. Breeding success was positively related to the abundance of anchovy Engraulis encrasicolus and sardine Sardinops sagax, and the high ...

  3. Short communications : Are wild African lungfish obligate air ...

    African Journals Online (AJOL)

    Laboratory studies have resulted in classification of the marbled African lungfish, Protopterus aethiopicus, as an obligate air-breather. However, there have been no investigations of the extent of dependence on aerial respiration by this species in the wild. We used radio telemetry to obtain quantitative information on the ...

  4. In vitro cytotoxicity of crude alkaloidal extracts of South African ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-07-20

    Jul 20, 2009 ... The cytotoxicity of crude alkaloid extracts obtained from the leaves and rhizomes of all the South. African members of the family Menispermaceae (seven genera and 13 species) was tested against. MCF7 (breast), UACC62 (melanoma) and TK10 (renal) cancer cell lines. Extracts of ten of the thirteen.

  5. Return to Robben Island of African Penguins that were rehabilitated ...

    African Journals Online (AJOL)

    Return to Robben Island of African Penguins that were rehabilitated, relocated or reared in captivity following the Treasure oil spill of 2000. ... All three conservation interventions are considered to have been successful, but it is premature to assess their relative contributions to the conservation of the species.

  6. South African Family Practice

    African Journals Online (AJOL)

    South African Family Practice(SAFP) is a peer-reviewed scientific journal, which strives to provide primary care physicians and researchers with a broad range of scholarly work in the disciplines of Family Medicine, Primary Health Care, Rural Medicine, District Health and other related fields. SAFP publishes original ...

  7. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Ethiopian Journal of Education and Sciences; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries? Southern African Business Review; Book Review: Insurance in Ethiopia: Historical Development, Present Status and Future ...

  8. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Featured Country: Nigeria, Featured Journal: Journal of the Obafemi Awolowo University Medical Student's Association (IFEMED) ... OGIRISI: a New Journal of African Studies; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international competitiveness of countries?

  9. East African Medical Journal

    African Journals Online (AJOL)

    East African Medical Journal Vol. 79 No. 5 May 2002. CIGARETTE SMOKING AND KHA'I' CHEWING AMONG UNIVERSITY INSTRUCTORS IN ETHIOPIA. Y. Kebede. MD, MPH, Gondar College of Medical Sciences, PO. Box 196, Gondar, Ethiopia. CIGARETTE SMOKING AND KHAT CHEWING AMONG UNIVERSITY ...

  10. African Health Sciences: Contact

    African Journals Online (AJOL)

    Principal Contact. Dr James Tumwine Editor-in-Chief. Makerere University Medical School P. O. Box 7072 Kampala Uganda. Phone: 256-41-530020/1. Email: kabaleimc@gmail.com. Support Contact. Pauline Salamula Email: paulinesalamula@gmail.com. ISSN: 1680-6905. AJOL African Journals Online. HOW TO USE ...

  11. African Journals Online (AJOL)

    African Journals Online (AJOL)

    The abnormal chest X-ray – when to refer to a specialist ... South African Journal of Education; The Basis of Distinction Between Qualitative and Quantitative Research in Social Science: Reflection on Ontological, ... EJOTMAS: Ekpoma Journal of Theatre and Media Arts; Effect of Globalization on Sovereignty of States

  12. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Southern African Business Review; Effect of Globalization on Sovereignty of States Nnamdi Azikiwe University Journal of International Law and Jurisprudence; The Influence of Motivation on Employees' Performance: A Study of Some Selected Firms in Anambra State AFRREV IJAH: An International Journal of Arts and ...

  13. African Journals Online (AJOL)

    African Journals Online (AJOL)

    Continuing Medical Education; The competitive advantage of nations: is Porter's Diamond Framework a new theory that explains the international ... Ethiopian Journal of Education and Sciences; The application of just administrative action in the South African environmental governance sphere: An analysis of some ...

  14. African Journals Online: Bulgaria

    African Journals Online (AJOL)

    ... Botswana, Brazil, British Indian Ocean Territory, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cabo Verde, Cambodia, Cameroon, Canada, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo, Democratic Republic, Congo, Republic, Costa Rica, Côte d'Ivoire, Croatia, Cuba ...

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    African Journals Online (AJOL)

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  16. African Journals Online: Belarus

    African Journals Online (AJOL)

    ... Botswana, Brazil, British Indian Ocean Territory, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cabo Verde, Cambodia, Cameroon, Canada, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo, Democratic Republic, Congo, Republic, Costa Rica, Côte d'Ivoire, Croatia, Cuba ...

  17. African Journals Online: Greenland

    African Journals Online (AJOL)

    ... Botswana, Brazil, British Indian Ocean Territory, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cabo Verde, Cambodia, Cameroon, Canada, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo, Democratic Republic, Congo, Republic, Costa Rica, Côte d'Ivoire, Croatia, Cuba ...

  18. South African Crime Quarterly

    African Journals Online (AJOL)

    South African Crime Quarterly is an inter-disciplinary peer-reviewed journal that promotes professional discourse and the publication of research on the subjects of crime, criminal justice, crime prevention, and related matters including state and non-state responses to crime and violence. South Africa is the primary focus for ...

  19. African Journals Online: Swaziland

    African Journals Online (AJOL)

    The journal publishes research papers, case studies, essays and review articles as well as first hand experiences in soil, plant, water and animal sciences, natural resources management, home economics and nutrition, and other related areas of relevance to the Southern African Development Community (SADC) region in ...

  20. African Journals Online (AJOL)

    African Journals Online (AJOL)

    AFRREV IJAH: An International Journal of Arts and Humanities; Book Review: Insurance in Ethiopia: Historical Development, Present Status and Future Challenges Journal of Business and Administrative Studies; Educational leadership and management: theory, policy and practice. South African Journal of Education ...