135 results on '"Wellington N"'
Search Results
2. In vivo schistosomicidal activity of (±)-licarin A-loaded poly(ε-caprolactone) nanoparticles
- Author
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Lima, Thais C., primary, Magalhães, Lizandra G., additional, de L. Paula, Lucas A., additional, Cunha, Wilson R., additional, Januário, Ana H., additional, Pauletti, Patricia M., additional, Bastos, Jairo K., additional, Mnuquian, Hallana Alves, additional, Forim, Moacir R., additional, Morais-Urano, Raquel P., additional, Laurentiz, Rosangela S., additional, Tondato, Wellington N., additional, Molina, Eduardo F., additional, Santos, Mario F.C., additional, and e Silva, Márcio L.A., additional
- Published
- 2022
- Full Text
- View/download PDF
3. In vivo schistosomicidal activity of (±)-licarin A-loaded poly(ε-caprolactone) nanoparticles
- Author
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Thais C. Lima, Lizandra G. Magalhães, Lucas A. de L. Paula, Wilson R. Cunha, Ana H. Januário, Patricia M. Pauletti, Jairo K. Bastos, Hallana Alves Mnuquian, Moacir R. Forim, Raquel P. Morais-Urano, Rosangela S. Laurentiz, Wellington N. Tondato, Eduardo F. Molina, Mario F.C. Santos, and Márcio L.A. e Silva
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Polyesters ,Immunology ,General Medicine ,Schistosoma mansoni ,Lignans ,Schistosomiasis mansoni ,ESQUISTOSSOMOSE MANSONI ,Lactones ,Mice ,Schistosomicides ,Infectious Diseases ,Animals ,Nanoparticles ,Parasitology ,Caproates - Abstract
Schistosomiasis mansoni is an infectious parasitic disease caused by worms of the genus Schistosoma, and praziquantel (PZQ) is the medication available for the treatment of schistosomiasis. However, the existence of resistant strains reinforces the need to develop new schistosomicidal drugs safely and effectively. Thus, the (±)-licarin A neolignan incorporated into poly-Ɛ-caprolactone (PCL) nanoparticles and not incorporated were evaluated for their in vivo schistosomicidal activity. The (±)-licarin A -loaded poly(ε-caprolactone) nanoparticles and the pure (±)-licarin A showed a reduction in the number of worm eggs present in spleens of mice infected with Schistosoma mansoni. In addition, the (±)-licarin A incorporated in the concentration of 20 mg/kg and 200 mg/kg reduced the number of worms, presenting percentages of 56.3% and 41.7%, respectively.
- Published
- 2022
4. How do minimum cigarette price laws affect cigarette prices at the retail level?
- Author
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Feighery, E C, Ribisl, K M, Schleicher, N C, Zellers, L, and Wellington, N
- Published
- 2005
5. The forest avifauna of Arabuko Sokoke Forest and adjacent modified habitats
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Wellington N. Kombe, David O. Chiawo, and Adrian J. F. K. Craig
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Geography ,geography.geographical_feature_category ,biology ,Important Bird Area ,Habitat ,Land use ,Abundance (ecology) ,Green barbet ,Forestry ,Vegetation ,biology.organism_classification ,Generalist and specialist species ,Old-growth forest - Abstract
Arabuko Sokoke Forest (ASF) is the largest area of coastal forest remaining in East Africa and a major Important Bird Area in mainland Kenya. The study analysed data from point count surveys over 15 months in three land use types; primary forest (PF), plantation forest (PL), and farmlands (FM), and compared these to the first comprehensive bird checklist for the forest, as well as recent surveys from other studies. Avifaunal diversity and abundance were compared using multivariate analysis to determine bird responses to different land use characteristics. The primary forest held a distinctive bird community, while the bird communities of farmlands and plantation forest were more similar to each other. Land use had a significant effect on overall avian diversity and abundance. The current forest avifauna was divided into forest specialists (16 species), forest generalists (26 species) and forest visitors (30 species). Seven species of forest specialist and generalists recorded prior to 1980 may no longer occur in the forest. Of 38 specialists and generalists recorded in our point counts, 19 were also recorded on farmland and 28 in plantations. One forest specialist, the Green Barbet, was most encountered outside the forest. Future research should focus on habitat use by these bird species, and the extent of movement by forest birds between the remaining patches of coastal forest. Patterns of habitat use by birds in the area suggest that vegetation heterogeneity and habitat complexity are especially significant in sustaining diverse and abundant bird populations. The management of plantations and farmland will be critical for the conservation of forest generalists and forest visitors.
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- 2021
6. The Experimental Infection of Calves with Mycobacterium ulcerans
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Tolhurst, Jean C., Buckle, Glen, and Wellington, N. A. M.
- Published
- 1959
7. The forest avifauna of Arabuko Sokoke Forest and adjacent modified habitats
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Chiawo, David O., primary, Kombe, Wellington N., additional, and Craig, Adrian J.F.K., additional
- Published
- 2021
- Full Text
- View/download PDF
8. Genome-wide association study identified candidate genes controlling continuous storage root formation and bulking in hexaploid sweetpotato
- Author
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Astere Bararyenya, Herbert Talwana, Yao Nasser, Wolfgang J. Grüneberg, Arfang Badji, Mercy Kitavi, Thomas Odong, Bode A. Olukolu, Jan W. Low, Martina Kyalo, M. Ochwo-Ssemakula, Wellington N. Ekaya, Phinehas Tukamuhabwa, Robert O. M. Mwanga, and Dorcus C. Gemenet
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0106 biological sciences ,0301 basic medicine ,Candidate gene ,Quantitative Trait Loci ,Polyploid ,Genome-wide association study ,Single-nucleotide polymorphism ,Plant Science ,Biology ,Quantitative trait locus ,Genes, Plant ,Plant Roots ,Polymorphism, Single Nucleotide ,01 natural sciences ,Genome ,03 medical and health sciences ,Plant Growth Regulators ,Sweetpotato ,lcsh:Botany ,GWAS ,GBSapp ,Ipomoea batatas ,Lateral root formation ,Genetics ,Indoleacetic Acids ,DArTseq ,Marker-assisted selection ,CSRFAB ,lcsh:QK1-989 ,030104 developmental biology ,Genotyping-by-sequencing ,Oxidation-Reduction ,Genome, Plant ,Genome-Wide Association Study ,Research Article ,SNPs ,010606 plant biology & botany ,Reference genome - Abstract
Background Continuous storage root formation and bulking (CSRFAB) in sweetpotato is an important trait from agronomic and biological perspectives. Information about the molecular mechanisms underlying CSRFAB traits is lacking. Results Here, as a first step toward understanding the genetic basis of CSRFAB in sweetpotato, we performed a genome-wide association study (GWAS) using phenotypic data from four distinct developmental stages and 33,068 single nucleotide polymorphism (SNP) and insertion-deletion (indel) markers. Based on Bonferroni threshold (p-value − 7), we identified 34 unique SNPs that were significantly associated with the complex trait of CSRFAB at 150 days after planting (DAP) and seven unique SNPs associated with discontinuous storage root formation and bulking (DCSRFAB) at 90 DAP. Importantly, most of the loci associated with these identified SNPs were located within genomic regions (using Ipomoea trifida reference genome) previously reported for quantitative trait loci (QTL) controlling similar traits. Based on these trait-associated SNPs, 12 and seven candidate genes were respectively annotated for CSRFAB and DCSRFAB traits. Congruent with the contrasting and inverse relationship between discontinuous and continuous storage root formation and bulking, a DCSRFAB-associated candidate gene regulates redox signaling, involved in auxin-mediated lateral root formation, while CSRFAB is enriched for genes controlling growth and senescence. Conclusion Candidate genes identified in this study have potential roles in cell wall remodeling, plant growth, senescence, stress, root development and redox signaling. These findings provide valuable insights into understanding the functional networks to develop strategies for sweetpotato yield improvement. The markers as well as candidate genes identified in this pioneering research for CSRFAB provide important genomic resources for sweetpotato and other root crops.
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- 2020
9. Morphodynamic studies in sandy Amazonian environments
- Author
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, Cajueiro Carneiro Pereira, Luci, Trindade, Wellington N., do Nascimento, Anderson Thiago, Vila Concejo, Ana, Jiménez Quintana, José Antonio, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, Cajueiro Carneiro Pereira, Luci, Trindade, Wellington N., do Nascimento, Anderson Thiago, Vila Concejo, Ana, and Jiménez Quintana, José Antonio
- Abstract
The present study evaluated the different morphodynamic scenarios that arise under varying tidal and wave conditions on a sandy beach (Ajuruteua) and an exposed tidal flat (Vila dos Pescadores) on the Amazon coast of northern Brazil. For this, four field campaigns were conducted, covering a full annual cycle, for the collection of nearshore data (tides, waves, rainfall, topographic changes, and sediment characteristics). These data were complemented with meteorological (rainfall), fluvial discharge and offshore (wave and wind) data obtained from the stations of official agencies. Ajuruteua beach has very fine sand (2.1-2.7 φ) with a typical profile characterized by a narrow high-tide zone (<10 m) and intertidal zone with a low-gradient (1°–2°) and varying width, ranging from 250 m (neap tide) to 350 m (spring tide). At that beach, tidal flat conditions occur primarily during the equinoctial period, when tidal asymmetry is strongest (ebb tide longer than 7 h). At Vila dos Pescadores, the sand is also fine (more than 70% of grain 2.0-3.0 φ) and the migration of the main tidal channel is delimited by a low, broad terrace. In this area, the transition between tide-dominated, tide-modified, and wave-dominated conditions occurs during the high tide, primarily during the dry season, when the highest Hs values (up to 1.3 m) are recorded on the tidal flat. In the study region, the unregulated construction of buildings has resulted in increasing impacts from erosive processes, which has partially or totally destroyed the existing beachfront infrastructure. The results of the present study provide important insights for the development of more effective management strategies for the local environments., This study was financed by CNPq through universal project. Pereira, L.C.C would also like to thank CNPq (309491/2018-5)., Peer Reviewed, Postprint (published version)
- Published
- 2020
10. Bird responses to land use change: guild diversity in a Kenyan coastal forest and adjoining habitats
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Wellington N. Kombe, David O. Chiawo, and Adrian J. F. K. Craig
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0106 biological sciences ,Land use ,Ecology ,Species diversity ,010603 evolutionary biology ,01 natural sciences ,010605 ornithology ,Ecosystem services ,Geography ,Habitat ,Guild ,Forest ecology ,Animal Science and Zoology ,Land use, land-use change and forestry ,Species richness ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation - Abstract
Land use change can have profound effects on forest ecology, particularly on the avian community. Arabuko-Sokoke Forest, one of the Important Bird Areas (IBAs) in Kenya, is under threat due...
- Published
- 2018
11. Modelling of Hydrological Drought Events in the Upper Tana Basin of Kenya
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C. M. Ondieki, Wellington N. Wamicha, and Jones F. Agwata
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Hydrology ,business.industry ,Generalized Pareto distribution ,Log-normal distribution ,Generalized extreme value distribution ,Water supply ,Environmental science ,Structural basin ,Frequency distribution ,business ,Extreme value theory ,Hydropower - Abstract
Drought is a recurring hazard which affects many parts of Kenya. In most countries in Sub-Saharan Africa, agriculture which is predominantly rain-fed is the main stay of the economies is highly prone to the impacts of drought which, whenever it occurs, leads to serious socioeconomic challenges at various levels. The study of drought duration, magnitude and severity have relevance in many areas such as waste load allocations, issuance of pollution discharge permits, location of treatment plants and sanitary landfills, determination of allowable water transfers and withdrawals both within, between and outside the affected areas and determination of minimum downstream release requirements for hydropower water supply, cooling plants and other facilities. Knowledge of the frequency distribution of the drought events is useful as it contributes to the assessment of drought risks which have implications on the long term ecological, economic and social well being of the biological and human communities that make use of water from the various streams in a basin. In this study five frequency distributions were fitted to drought duration and severity as determined from discharge data from representative river gauge stations in the upper Tana Basin of Kenya. The frequency distributions fitted to the two drought events were the Generalized Normal (GN) or 3-parameter Lognormal, Generalized Extreme Value (GEV) or the Extreme Value Type III, Generalized Pareto (GPA), Pearson Type III (P3) and Generalized Logistic (GL). The distributions of best fit for the drought events were identified using the Z value obtained from the average L-moment statistics of a particular candidate distribution and the average L-moment statistics. The Z value for each homogenous region was determined from sample estimates of Lcv , Lcs and Lck that were determined from probability weighted moment estimators and the weighted means of Lcv, Lcs and Lck using records from the river gauging stations representing each hydrologically homogenous region. A frequency distribution of best fit was selected if ׀Z Dis ׀ ≤ 1.64 and the one with the lowest ׀Z Dis ׀ value selected as the distribution
- Published
- 2014
12. Bird responses to land use change: guild diversity in a Kenyan coastal forest and adjoining habitats
- Author
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Chiawo, David O., primary, Kombe, Wellington N., additional, and Craig, Adrian J. F. K., additional
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- 2018
- Full Text
- View/download PDF
13. Conservation and human livelihoods at the crossroads: Local needs and knowledge in the management of Arabuko Sokoke Forest
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Chiawo, David O., primary, Kombe, Wellington N., additional, and Craig, Adrian J.F.K., additional
- Published
- 2017
- Full Text
- View/download PDF
14. Regime de queima em Goiás, Brasil, e em Moçambique entre 2010 e 2019: frequência, recorrência e classes de cobertura mais afetadas
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Sara Alves dos Santos, Wellington Nunes de Oliveira, Noely Vicente Ribeiro, and Nilson Clementino Ferreira
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fogo ,recorrência ,savanas ,uso e cobertura da terra ,queima de biomassa. ,Environmental sciences ,GE1-350 - Abstract
Nos últimos anos, o mundo tem experienciado eventos extremos relacionados à ocorrência do fogo, que vêm causando uma série de danos às populações e ecossistemas. Em 2020 incêndios assolaram Austrália, Brasil, Estados Unidos, entre outras nações. Isso dá à temática dos incêndios florestais relevância e urgência globais e torna necessários a maior compreensão e o monitoramento desses eventos. O presente trabalho buscou identificar semelhanças e diferenças no regime de fogo, mais especificamente na frequência e recorrência, entre Moçambique e no Estado de Goiás, Brasil, entre 2010 e 2019. Ambos os recortes estão localizados na mesma zona bioclimática, onde estão presentes as savanas. Estas, consideradas ecossistemas com maior resiliência ao fogo, não estão imunes às consequências de incêndios intensos e frequentes. Logo, monitorar tais eventos nesses ecossistemas é importante, principalmente para identificar características que possam nortear a tomada de decisões. As etapas metodológicas para o desenvolvimento da presente pesquisa envolveram organização de base de dados e uso de plataformas de processamento geoespacial baseado em nuvem, o que resultou em produtos de caracterização dos eventos de queima. Em ambos os recortes estudados, o fogo ocorre anualmente em extensões consideráveis, principalmente no caso de Moçambique, cujo percentual de área queimada anualmente é maior que o de Goiás. Tal dinâmica pode estar relacionada a especificidades de cada região. Os presentes resultados possibilitam melhor compreensão de como se dá a ocorrência de incêndios e queimadas em diferentes savanas e podem motivar outras pesquisas a respeito, com vistas a maiores esclarecimentos.
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- 2022
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15. First fatty acylated dipeptides to affect muscarinic receptor ligand binding
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Krishnan, Vyjayanthi, Pham, Wellington N., Messer, William S., Jr., and Peseckis, Steven M.
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- 1999
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16. Application of the DPSIR framework to the evaluation of the recreational and environmental conditions on estuarine beaches of the Amazon coast
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, de Sousa, Rosigleyse C., Pereira, Luci Cajueiro Carneiro, Trindade, Wellington N., da Costa, Rauquírio Marinho, Jiménez Quintana, José Antonio, Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental, Universitat Politècnica de Catalunya. LIM/UPC - Laboratori d'Enginyeria Marítima, de Sousa, Rosigleyse C., Pereira, Luci Cajueiro Carneiro, Trindade, Wellington N., da Costa, Rauquírio Marinho, and Jiménez Quintana, José Antonio
- Abstract
The present study proposes a diagnosis of the conditions and impacts on estuarine beaches of the Amazonian coast based on the application of the DPSIR (Driving Forces, Pressures, State, Impact, Responses) model, which identifies the natural and anthropogenic drivers affecting the environment. Natural drivers are related primarily to the accentuated hydrodynamic processes, high rainfall and fluvial discharge. The anthropogenic driver is related to the lack of planning for beach development. These human pressures result in a reduction in the quality of the beaches through microbiological contamination, the accumulation of garbage on the sand and in the water, sewage outfalls, and overcrowding which, combined with the intense local hydrodynamics and the lack of planning of recreational activities (zoning, warning signs, lifeguard coverage) may increase the risk of accidents for beachgoers, such as drowning, and injuries caused by motorboats, jet skis and stingrays. Despite all the problems identified, no response whatsoever was observed from the local authorities. The results of the DPSIR analysis indicate an urgent need for the implementation of beach management plans to improve the conditions of the beaches and in particular their safety, as well as identifying the obligations of the local authorities responsible for the future development of the Amazon coast., Peer Reviewed, Postprint (author's final draft)
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- 2017
17. Evaluation of forage legumes for introduction into natural pastures of semi-arid rangelands of Kenya
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J.G. Mureithi, P.N Macharia, Jenesio I. Kinyamario, Wellington N. Ekaya, E. G. Thuranira, and Ckk Gachene
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biology ,Lablab purpureus ,Crop yield ,Management, Monitoring, Policy and Law ,Dolichos ,biology.organism_classification ,food.food ,food ,Agronomy ,Dry matter ,Soil fertility ,Agronomy and Crop Science ,Legume ,Mucuna pruriens ,Macroptilium atropurpureum - Abstract
To address the potential of legumes to contribute to improved quality and quantity of natural pastures in the semi-arid rangelands of Kenya, five legume species were introduced and evaluated in a small-plot field experiment over three growing seasons. The investigated species were glycine (Neonotonia wightii), siratro (Macroptilium atropurpureum), dolichos (Lablab purpureus cv. Rongai), velvet bean (Mucuna pruriens) and shrubby stylo (Stylosanthes scabra cv. seca). Treatments included two cutting heights (ground level and 15 cm) and two cutting intervals (at 2 and 4 months). The mean dry matter (DM) yields of glycine and siratro were highest when the legumes were harvested at ground level at 2-month intervals (10·31 and 7·81 t ha−1 year−1 respectively). Mean DM yield of stylo was highest when the legume was harvested at 15 cm after 4 months (3·52 t ha−1 year−1). These three legumes also produced high organic matter through litter fall, which contributed to soil fertility. Evidence from a supporting pot experiment showed effective nodulation and potential for N fixation. These legumes also possessed deep tap roots and withstood heavy defoliation. These three legumes were selected for further integration with grasses in natural pastures. The DM yields of dolichos and velvet bean when harvested at 15 cm after 2 or 4 months were low (2·48 and 1·91 t ha−1 year−1), and these species were considered inappropriate for further investigation.
- Published
- 2010
18. Effects of human-livestock-wildlife interactions on habitat in an eastern Kenya rangeland
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John Otuoma, Jenesio I. Kinyamario, Wellington N. Ekaya, Mrigesh Kshatriya, and Meshak Nyabenge
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Geography ,Habitat destruction ,business.industry ,Ecology ,Grazing ,Wildlife ,Biological dispersal ,Livestock ,Vegetation ,Rangeland ,business ,Population density ,Ecology, Evolution, Behavior and Systematics - Abstract
Human–livestock–wildlife interactions have increased in Kenyan rangelands in recent years, but few attempts have been made to evaluate their impact on the rangeland habitat. This study identified drivers of increased human–livestock–wildlife interactions in the Meru Conservation Area between 1980 and 2000 and their effects on the vegetation community structure. The drivers were habitat fragmentation, decline in pastoral grazing range, loss of wildlife dispersal areas and increase in livestock population density. Agricultural encroachment increased by over 76% in the western zone adjoining Nyambene ranges and the southern Tharaka area, substantially reducing the pastoral grazing range and wildlife dispersal areas. Livestock population increased by 41%, subjecting areas left for pastoral grazing in the northern dispersal area to prolonged heavy grazing that gave woody plant species a competitive edge over herbaceous life-forms. Consequently, open wooded grassland, which was the dominant vegetation community in 1980, decreased by c. 40% as bushland vegetation increased by 42%. A substantial proportion of agro pastoralists were encountered around Kinna and Rapsu, areas that were predominantly occupied by pastoralists three decades ago, indicating a possible shift in land use in order to spread risks associated with habitat alterations. Resume Les interactions hommes-betail-faune sauvage ont augmente dans les pâturages kenyans ces dernieres annees, mais il y a eu peu de tentatives pour evaluer leur impact sur cet habitat. Cette etude identifie quelles ont ete les raisons sous-jacentes de ces interactions dans l’Aire de Conservation de Meru entre 1980 et 2000, et leurs effets sur la structure de la communaute vegetale. Les raisons etaient la fragmentation de l’habitat, le declin de la surface libre pour le pâturage pastoral, la perte d’aire de dispersion pour la faune sauvage et l’augmentation de la densite de population du betail. L’envahissement agricole a augmente de plus de 76% dans la zone ouest touchant les fermes de Nyambene et l’aire sud de Tharaka, reduisant substantiellement l’etendue du pâturage pastoral et les aires de dispersion de la faune sauvage. La population du betail a augmente de 41%, soumettant les etendues laissees au pâturage pastoral dans la region de dispersion nord a un pâturage intensif prolonge qui a donne aux especes vegetales ligneuses un avantage sur les formes herbeuses. Par consequent, la prairie arboree ouverte, qui etait la communaute vegetale dominante dans les annees 1980 a diminue de pres de 40% alors que la vegetation de broussailles a augmente de 42%. Une proportion substantielle d’agropastoralistes se rencontraient autour de Kinlla et de Rapsu, des zones qui etaient principalement occupees par des pasteurs il y a trois decennies, ce qui indique une evolution possible de l’utilisation des sols afin de disperser les risques lies a l’alteration des habitats.
- Published
- 2009
19. A FORMAÇÃO HISTÓRICA DA PESCA ARTESANAL: ORIGENS DE UMA CULTURA DO TRABALHO APOIADA NO SENTIMENTO DE ARTE E DE LIBERDADE
- Author
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Ramalho, Cristiano Wellington N.
- Subjects
Social sciences (General) ,H1-99 ,cultura do trabalho pesqueiro ,pernambuco ,arte ,autonomia ,lcsh:H1-99 ,lcsh:Social sciences (General) ,pescadores artesanais - Abstract
O presente texto busca comprender as raízes sócio-históricas contidas na cultura do trabalho dos pescadores artesanais pernambucanos, a qual liga seu saber-fazer pesqueiro às categorias arte e autonomia. Nesse sentido, o passado torna-se campo fértil para encontrarmos – nos dias de hoje - vários aspectos que repercutem nas “formas de ser” e nas “determinações de existência” pertencentes à organização produtiva da pesca artesanal. Palavras-Chave: Pescadores artesanais, arte, autonomia, cultura do trabalho pesqueira, Pernambuco. This text intends to understand the socio-historical roots in the culture of the artisanal fishermen work from Pernambuco, which connects its fishing know-how to the category of art and autonomy. In that sense, the past becomes a fertile field to find – nowadays – several aspects that impact on “ways to be” and the “determination of existence” belonging to the productive fishing organization. Key words: Fishermen craft, art, autonomy, work culture of fishing, Pernambuco.
- Published
- 2008
20. Behavioral influences on risk of exposure to fecal contamination in low-resource neighborhoods in Accra, Ghana
- Author
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Hurd, J., primary, Hennink, M., primary, Robb, K., primary, Null, C., primary, Peprah, D., primary, Wellington, N., primary, Yakubu, H., primary, and Moe, C. L., primary
- Published
- 2017
- Full Text
- View/download PDF
21. Genetic variation between ecotypic populations ofChloris roxburghianagrass detected through RAPD analysis
- Author
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J. W. Stuth., G Lall, Jean Hanson, W Ngoyawu Mnene, Wellington N. Ekaya, R. H Jamnadass, Jenesio I. Kinyamario, and P Mweki
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Germplasm ,education.field_of_study ,Genetic diversity ,Ecology ,Ecotype ,Population ,UPGMA ,food and beverages ,Biology ,Analysis of molecular variance ,RAPD ,Botany ,Genetic variation ,Animal Science and Zoology ,education - Abstract
Chloris roxburghiana is an important rangeland grass in Kenya. In some areas it has disappeared due to land degradation resulting from overgrazing and drought. Efforts to re-introduce the grass through re-seeding using seeds from research stations have had little success. One possible reason for low establishment is attributed to transplanting spatially separated populations that may represent genetically distinct ecotypes. To test this hypothesis, germplasm diversity within and among four populations of C. roxburghiana from four ecologically distinct sites was analysed using random amplified polymorphic DNA (RAPD) markers. A total of 131 polymorphic markers were identified using nine RAPD primers. There was significant variation among populations, with genetic diversity (H) ranging from 0.134 to 0.206. Analysis of molecular variance (AMOVA) revealed most variance within populations (76%). However, the variation among populations was also significant (24%). The UPGMA of the population frequency indicated ...
- Published
- 2005
22. Reaching the marginalised? Gender value chains and ethical trade in African horticulture
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Motsosi E, D. M. Mbuvi, Muroki Nm, Okunade Eo, Torimiro Do, Alimi T, Demombynes G, Deji Of, J. G. Adewale, Ngichabe Ck, Ayanwale Ab, Farinde Aj, Laogun Ea, Evenson Re, Kolawole Od, Smith S, J. Steinbach, Holden S, Kouame A, S. Barrientos, Kogi-Makau W, Lipton M, Veronicah K, Siegel M, L. O. Olarinde, F. A. Kuponiyi, Oladele Oi, Olayiwola Lm, DeVoe D, Tefera T, M. Okoti, Kirk M, Mathias E, Adeleye Oa, Schellekens J, Kameri-Mbote P, Clemens M, Barbara Rischkowsky, C. Dolan, S. Homann, A. Tallontire, J. C. Ng’ethe, and Wellington N. Ekaya
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Economic growth ,Food security ,business.industry ,Agriculture ,Geography, Planning and Development ,Environmental resource management ,Social Welfare ,Hiv services ,Development ,Livelihood ,business - Abstract
These success stories describe how two programs helped families to strengthen their health agricultural livelihoods and food security in Malawi. The programs helped households to grow more food guided farmers toward profitable business practices helped people to form savings groups taught families and young mothers about health and nutrition and increased access to HIV services and social welfare systems.
- Published
- 2005
23. The Impact of Rangeland Condition and Trend to the Grazing Resources of a Semi-arid Environment in Kenya
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Wellington N. Ekaya and P.N Macharia
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Agroforestry ,05 social sciences ,Forestry ,030206 dentistry ,General Medicine ,Vegetation ,050601 international relations ,Fencing ,Grazing pressure ,0506 political science ,03 medical and health sciences ,0302 clinical medicine ,Deforestation ,Soil retrogression and degradation ,Grazing ,Environmental science ,Rangeland ,Overgrazing - Abstract
A research study was conducted in Mashuru Division of Kajiado District, Kenya with the objective of analyzing the types of vegetation degradation, their causes and their influence on rangeland condition and trend. The study was conducted through remote sensing tools, ground truthing, interviews, community workshop and literature. The results of the study showed that excessive use of the woody species by humans for woodfuel, building and fencing materials, medicine and ornamentals had led to the deterioration of the rangeland due to a loss of cover, change in plant composition and biodiversity. On the other hand, overgrazing and ecological succession of the grazing lands had led to further vegetation degradation in form of bush encroachment and thickening. These types of vegetation degradation have had an overall effect of loss of grass cover and hence loss of grazing capacity by livestock, especially cattle. The causes of vegetation decrease or increase over the last 30 years have been due to deforestation (trees and shrubs), bush encroachment and thickening , change in plant species composition and natural calamities such as droughts, wild fires and army worm invasions at various times. The overall results indicated that there has been a downward trend in range condition over the last 30 years which has affected the livestock productivity of the area.
- Published
- 2005
24. Land Use, Ecology, and Socio-economic Changes in a Pastoral Production System
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J. C. Ng’ethe, M. Okoti, D. M. Mbuvi, and Wellington N. Ekaya
- Subjects
education.field_of_study ,Land use ,Ecology ,05 social sciences ,Pastoralism ,Population ,Nomadic pastoralism ,030206 dentistry ,General Medicine ,Vegetation ,050601 international relations ,Fencing ,0506 political science ,03 medical and health sciences ,0302 clinical medicine ,Geography ,Human settlement ,Rangeland ,Socioeconomics ,education - Abstract
This study was conducted in the northern part of Kenya, in Kakuma division, Turkana district. Kakuma is a semi- arid area under nomadic pastoralism as the main activity. The presence of a refugee camp has attracted many people from within the Turkana community and also the outside community. The study aimed at documenting the effects of emergent land use changes on vegetation resources and the socio-economic environment in Kakuma. Data on vegetation density and cover was collected. Socio-economic data was collected from the local Turkana population and the settlement camp. The data was analysed using SPSS computer package and descriptive statistics. There was a significant difference (P
- Published
- 2004
25. Indigenous Knowledge: The Basis of The Maasai Ethnoveterinary Diagnostic Skills
- Author
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Miaron O. Jacob, KO Farah, and Wellington N. Ekaya
- Subjects
medicine.medical_specialty ,Traditional medicine ,business.industry ,Pastoralism ,Alternative medicine ,Maasai ,General Medicine ,language.human_language ,Indigenous ,medicine ,language ,Livestock ,Traditional knowledge ,business ,Socioeconomics - Abstract
The Maasai indigenous knowledge of animal diseases is comparable to the conventional knowledge of the modern veterinarian. Their diagnostic skills of livestock diseases is based on indigenous symptoms of diseases, vectors of diseases, season effects and species affected. The pastoralist diagnostic skills appear to be superior to those of agropastoralists. With the advent of modern veterinary medicine, the Maasai ethnoveterinary practice appears to be on the decline. This paper focuses on indigenous knowledge basis for diagnosis, treatment and control of selected examples of livestock diseases. In addition, the impact of modern veterinary medicine on pastoral (Maasai) ethnoveterinary practice will be briefly discussed.
- Published
- 2004
26. The nutritional value ofZizyphus spina-christifor goat production among the pastoralists of Kalu district, South Wello, Ethiopia
- Author
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Nashon K. R. Musimba, Wellington N. Ekaya, KO Farah, and K Y Dawd
- Subjects
Ecology ,biology ,Pastoralism ,food and beverages ,Forage ,Ziziphus ,Cynodon dactylon ,biology.organism_classification ,Nutrient ,Animal science ,Agronomy ,Dry season ,Animal Science and Zoology ,Dry matter ,Fibre content - Abstract
Fifteen yearling goats of similar weight were used to evaluate the potential of Zizyphus spina-christi leaves as a supplement to goats fed on Cynodon dactylon grass. Animals were randomly assigned to five feeding regimes and individually stall-fed for a preliminary period of 14 days, followed by 14 days of feeding to determine dry matter intake and digestibility and a 3-month feeding period to determine body weight changes. The treatments were formulated based on leaf:grass ratios of 0%, 25%, 50%, 75% and 100%. Z. spina-christi leaves had higher crude protein and lower fibre content than C. dactylon grass (P Z. spina-christi foliage is a potential feed supplement in the dry season, as the dry season grasses are deficient in the required nutrients and cannot meet goat requirements. African Journal of Range & Forage Science 2003, 20(3): 265–270
- Published
- 2003
27. Land Use and Spatial Distribution of Two Gum and Incense Producing Tree Species in the Blue-nile Valley of Wogidi District, Ethiopia
- Author
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KO Farah, Nashon K. R. Musimba, Wellington N. Ekaya, and Chane G. Turi
- Subjects
Land use ,05 social sciences ,Forestry ,030206 dentistry ,General Medicine ,Vegetation ,Spatial distribution ,050601 international relations ,0506 political science ,Incense ,03 medical and health sciences ,0302 clinical medicine ,Geography ,Tree species - Abstract
The study was conducted in the Blue-Nile valley of Wogidi district in Ethiopia, where woody vegetation degradation associated with intensive land use activities has become a national concern. It wa...
- Published
- 2003
28. Effect of Moisture Availability on Nitrogen and Phosphorus Uptake by Plants Under Semi-arid Soil Conditions
- Author
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P.N Macharia and Wellington N. Ekaya
- Subjects
Moisture availability ,Moisture ,Phosphorus ,food and beverages ,chemistry.chemical_element ,General Medicine ,Biology ,Nitrogen ,Arid ,chemistry ,Agronomy ,Soil water ,Seeding ,Legume - Abstract
A study was conducted in the semi-arid Kibwezi division of Kenya to investigate the effect of moisture availability on nitrogen and phosphorus uptake by plants. The study consisted of four treatments i.e. control, grass, legume, and grass/legume mixture. These were replicated on two sites with different soils. On each site, two sets of treatment were set up whereby one was WATER AVAILABILITY ON NITROGEN AND PHOSPHORUS UPTAKE BY RANGE PLANTS 361 given additional water, whereas one remained unwatered. The experiment was conducted during the short and the long rains. CP and P contents were determined for each of the treatments and seasons. The CP content of plants generally decreased as they grew from vegetative to seeding stage. Watering had no significant effect (P
- Published
- 2002
29. Production and decomposition of plant litter in an arid rangeland of Kenya
- Author
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Wellington N. Ekaya, Jenesio I. Kinyamario, and Research funded by the UNEP Project on climate change and the productivity of tropical grasslands
- Subjects
chemistry.chemical_classification ,Nutrient cycle ,Ecology ,Forage ,Plant litter ,Arid ,chemistry ,Agronomy ,Litter ,Environmental science ,Animal Science and Zoology ,Organic matter ,Ecosystem ,Quadrat - Abstract
Data on litter production and decomposition in an arid rangeland in Kenya was collected over a two-year period. Litter sampling was carried out at monthly intervals using a rectangular 0.25m-2 quadrat frame. Litter within the quadrats was handpicked and washed with running water to get rid of soil particles, dried, and weighed. Weights were expressed on organic matter basis. Monthly litter production ranged from 31.4g m-2 to 130.0g m-2. Mean monthly yield was 92.5 ± 26g m-2, with a 28% coefficient of variation. There was no significant difference (p>0.01) in litter yield between 1992 and 1993. Rate of decomposition for aboveground material ranged from 0.005g g-1 day-1 to 0.084g g-1 day-1. The mean annual rate of decomposition was 0.026g g-1 day-1. Belowground plant material rates of decomposition spread from 0.009g g-1 day-1 to 0.062g g-1 day-1, with a mean annual rate of 0.041g g-1 day-1. Belowground material consistently decomposed faster than aboveground material. Peaks in both aboveground and belowground material decomposition rates coincided with rainfall peaks. Overall, in this arid environment, litter production and decomposition is pulsed in nature, and trends are closely related to rainfall occurrence. Moisture is thus a limiting factor both to the production and decomposition of litter. Belowground litter plays a significant role in nutrient cycling. Keywords: dead herbage yield; dryland ecosystem; ecosystem function; nutrient cycling African Journal of Range & Forage Science 2001, 18(2&3): 125-129
- Published
- 2001
30. Woodlands and Livelihoods of African Pastoralists: The Massai of Kajiado, Kenya
- Author
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Wellington N. Ekaya and Jenesio I. Kinyamario
- Subjects
Geography ,Agroforestry ,Pastoralism ,Maasai ,language ,General Social Sciences ,Woodland ,Livelihood ,language.human_language - Published
- 2001
31. Nutritional Characteristics of Selected Grass and Browse Species From Kenya’s Pastoral Ecosystems
- Author
-
Wellington N. Ekaya
- Subjects
Geography ,Ecology ,food and beverages ,Ecosystem ,General Medicine ,Rangeland ,Nutrient content - Abstract
A study was conducted to determine the nutritional characteristics of selected grass and browse species from “Kenya” rangelands. The identified species were analyzed for their chemical composition ...
- Published
- 2001
32. Guillermo Orozco Gómez: uma trajetória no campo da comunicação e educação
- Author
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Adilson Odair Citelli and Wellington Nardes
- Subjects
Guilhermo Orozco Gómez ,Entrevista ,Tecnologias ,Escolas ,Comunicação e Educação ,Special aspects of education ,LC8-6691 ,Communication. Mass media ,P87-96 - Abstract
Publicada em caráter inédito neste número da revista Comunicação & Educação, a entrevista de Guilherme Orozco Gómez para Adilson Citelli e Wellington Nardes foi realizada via e-mail e submetida a trocas dialógicas envolvendo entrevistado e entrevistadores. Orozco Gómez elabora reflexões que atravessam os âmbitos da teoria e da metodologia em comunicação; comunicação e educação; lugar das tecnologias em nossa quadra histórica; impactos da pandemia nas escolas do México; desafios presentes e futuros a serem enfrentados pelas unidades educativas formais. Manifesta-se, ainda, acerca da importância que as obras de Jesus Martín-Barbero e Paulo Freire tiveram para o seu amadurecimento teórico e para as pesquisas que continua realizando.
- Published
- 2022
33. Conservation and human livelihoods at the crossroads: Local needs and knowledge in the management of Arabuko Sokoke Forest.
- Author
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Chiawo, David O., Kombe, Wellington N., and Craig, Adrian J. F. K.
- Subjects
- *
FOREST conservation , *CONSERVATION of natural resources , *FOREST management , *PLANT conservation , *INCOME , *NATURE conservation , *BASIC needs - Abstract
Abstract: Arabuko Sokoke Forest is the largest remaining single block of indigenous dry coastal tropical forest in Eastern Africa. Households within a 5 km buffer zone depend heavily on the forest for their livelihood needs, and the pressure on forest resources is on the increase. In May 2015, 109 households were interviewed on resources they obtain from the forest, in terms of the self‐reported level of monthly income. We found household income and farm size significantly positively correlated with benefits from the forest, highlighting the possible influence of household wealth in exploiting forest resources. A large proportion of households (32%) had limited knowledge of local birds, while human–bird conflict was reported by 44% of the households. While many households were keen to participate in conservation projects that maintain the forest, 44% had no knowledge of the forest management plan, and 60% of those interviewed had no idea of how forest zones were designated for particular activities. Drivers for local community participation in conservation projects appear to be sustainable income and fulfilment of basic household needs. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
34. Seedbed preparation influence on morphometric characteristics of perennial grasses of a semi-arid rangeland in Kenya
- Author
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Opiyo, Francis EO, Ekaya, Wellington N, Nyariki, Dickson M, and Mureithi, Stephen Mwangi
- Subjects
Agriculture and Food Sciences ,Perennial grasses ,morphometric characteristics ,ripping ,food and beverages ,semi-arid rangelands ,hand-clearing ,reseeding - Abstract
Semi-arid rangelands in Kenya are an important source of forage for both domestic and wild animals. However, indigenous perennial grasses notably Cenchrus ciliaris (African foxtail grass), Eragrostis superba (Maasai love grass) and Enteropogon macrostachyus (Bush rye grass) are disappearing at an alarming rate. Efforts to re-introduce them through restoration programs have often yielded little success. This can partly be attributed to failure of topsoil to capture and store scarce water to meet germination and plant growth requirements. A study was undertaken in the semi-arid environment of eastern Kenya to determine the effects of land treatment on morphometric characteristics of E. superba, C. ciliaris and E. macrostachyus. Seed viability of the grasses was estimated by germination tests. Land treatments involved soil ripping using a tractor and hand-clearing. Thirty-five plants were randomly selected per sub-plot and tagged for sampling. Morphometric characteristics of the grass species were measured weekly. Aboveground biomass was estimated by harvesting standing biomass three months after establishment. Seed viability tests showed significant differences (p
- Published
- 2011
35. The Role of Moisture in the Successful Rehabilitation of Denuded Patches of a Semi-Arid Environment in Kenya
- Author
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Moses Nyangito, Wellington N. Ekaya, Kevin Z. Mganga, W.M. Muiri, N.K.R. Musimba, J. Francis, R. Von Kaufman, Nashon K. R. Musimba, Agnes W. Mwang’ombe, Arianne P. Verhagen, and D. Clavel
- Subjects
business.product_category ,Perennial grasses ,biology ,Perennial plant ,Primary production ,Land Use and Food Security ,Landgebruik en Voedselzekerheid ,References ,biology.organism_classification ,Arid ,Plough ,Cenchrus ciliaris ,Agronomy ,Loam ,Foxtail ,Eragrostis superba ,Micro-carchments ,Rangeland ,business ,General Environmental Science - Abstract
This study investigated the role of moisture in the successful rehabilitation of denuded patches in semi-arid lands of Kenya and the primary productivity of three perennial rangelands grasses namely Cenchrus ciliaris (African foxtail), Enteropogon macrostachyus (Bush rye) and Eragrostis superba (Maasai love grass) at three phenological stages (early growth, elongation and reproduction) as pure stands and two-grass mixtures. The grasses were sown on either rainfed (Sites 1 and 2) or simulated rainfall conditions (site 3). Site preparation in all the 3 sites involved mechanical bush clearing, use of fire and creation of micro-catchments using an ox-drawn plough. Soils in site 3 were sandy clay loams and those in sites 1 and 2 were sandy clays. There was total failure in establishment sites 1 and 2 under natural rainfall. Site 3 had good germination and subsequent establishment. These results were attributed to the moisture conditions in the three sites. There was a significant difference (p
- Published
- 2011
36. Modelling of Hydrological Drought Events in the Upper Tana Basin of Kenya
- Author
-
Iosr Journals, Jones F. Agwata , Wellington N. Wamicha , Christopher M. Ondieki, Iosr Journals, and Jones F. Agwata , Wellington N. Wamicha , Christopher M. Ondieki
- Published
- 2014
- Full Text
- View/download PDF
37. Determinants of woody cover in African savannas
- Author
-
Alioune Diouf, Steven I. Higgins, Mahesh Sankaran, Feetham Banyikwa, Jonas Ardö, William B. Sea, Niall P. Hanan, Nick Zambatis, Xavier Le Roux, Susan Ringrose, Herbert H. T. Prins, Kelly K. Caylor, Andries Bronn, Jacques Gignoux, Jörg Tews, Gabriela Bucini, Pierre Hiernaux, Brian S. Cade, Halszka Hrabar, Christie J. Feral, Michael B. Coughenour, Jayashree Ratnam, David J. Augustine, Edmund C. February, Robert J. Scholes, Kristine L. Metzger, Jeff Worden, Peter G. H. Frost, Wellington N. Ekaya, Fulco Ludwig, Natural Resource Ecology Laboratory [Fort Collins] (NREL), Colorado State University [Fort Collins] (CSU), Division of Forest Science and Technology, USDA Forest Service, Commanche National Grassland, US Geological Survey [Fort Collins], United States Geological Survey [Reston] (USGS), Fonctionnement et évolution des systèmes écologiques (FESE), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Helmholtz Zentrum für Umweltforschung = Helmholtz Centre for Environmental Research (UFZ), Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM), Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS), CSIRO Centre for Environment and Life Sciences, Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Department of Botany, University of Dar es Salaam (UDSM), Department of Agriculture and Game Management, Port Elizabeth Technikon, Department of Civil and Environmental Engineering, Princeton University, Centre de Suivi Ecologique [Dakar] (CSE), Department of Range Management, University of Nairobi (UoN), Environmental Sciences Department, University of Virginia, University of Cape Town, Institute of Environmental Studies, University of Zimbabwe (UZ), Centre d'études spatiales de la biosphère (CESBIO), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), University of Pretoria [South Africa], Department of Zoology, University of Wisconsin-Madison, Resource Ecology Group, Wageningen University and Research [Wageningen] (WUR), Harry Oppenheimer Okavango Research Center, University of Botswana, Plant Ecology & Nature Conservation, University of Potsdam = Universität Potsdam, Scientific Services, Kruger National Park, Natural Resource Ecology Laboratory, University of Colorado Boulder [Boulder], United States Geological Survey [Reston] ( USGS ), Fonctionnement et évolution des systèmes écologiques ( FESE ), École normale supérieure - Paris ( ENS Paris ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Centre National de la Recherche Scientifique ( CNRS ), Umweltforschungszentrum Leipzig Halle, Sekt Okosyst Anal, Ecologie microbienne ( EM ), Centre National de la Recherche Scientifique ( CNRS ) -Ecole Nationale Vétérinaire de Lyon ( ENVL ) -Université Claude Bernard Lyon 1 ( UCBL ), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique ( INRA ) -VetAgro Sup ( VAS ), Commonwealth Scientific and Industrial Research Organisation [Canberra] ( CSIRO ), Department of Physical Geography and Ecosystems Analysis [Lund], University of Dar es Salaam ( UDSM ), Centre de Suivi Ecologique, University of Nairobi ( UoN ), University of Virginia [Charlottesville], University of Zimbabwe, Centre d'études spatiales de la biosphère ( CESBIO ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National d'Etudes Spatiales ( CNES ) -Centre National de la Recherche Scientifique ( CNRS ), Mammal Research Institute, University of Wisconsin-Madison [Madison], Wageningen University and Research Centre [Wageningen] ( WUR ), Potsdam University, École normale supérieure - Paris (ENS Paris), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Ecole Nationale Vétérinaire de Lyon (ENVL), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universität Potsdam, École normale supérieure - Paris (ENS Paris)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Helmholtz Zentrum für Umweltforschung (UFZ), Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Vétérinaire de Lyon (ENVL)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de la Recherche Agronomique (INRA)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Wageningen University and Research Centre [Wageningen] (WUR)
- Subjects
0106 biological sciences ,Canopy ,010504 meteorology & atmospheric sciences ,quantile regression ,Rain ,Biome ,Plant Ecology and Nature Conservation ,[SDV.BID]Life Sciences [q-bio]/Biodiversity ,Poaceae ,010603 evolutionary biology ,01 natural sciences ,[ SDV.EE ] Life Sciences [q-bio]/Ecology, environment ,Trees ,Soil ,DISPONIBILITE D'ELEMENT NUTRITIF ,vegetation ,Animals ,Ecosystem ,Biomass ,0105 earth and related environmental sciences ,[ SDV.BID ] Life Sciences [q-bio]/Biodiversity ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,Herbivore ,[ SDE.BE ] Environmental Sciences/Biodiversity and Ecology ,mechanisms ,Multidisciplinary ,WIMEK ,SUBTANCE NUTRITIVE ,Ecology ,FEU ,Vegetation ,15. Life on land ,stability ,PE&RC ,Arid ,Wood ,Geography ,Disturbance (ecology) ,Wildlife Ecology and Conservation ,ZONE SEMI-ARIDE ,Africa ,Plant cover ,Plantenecologie en Natuurbeheer ,systems ,Desert Climate ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,fire ,tree-grass coexistence - Abstract
Savannas are globally important ecosystems of great significance to human economies. In these biomes, which are characterized by the co-dominance of trees and grasses, woody cover is a chief determinant of ecosystem properties. The availability of resources (water, nutrients) and disturbance regimes (fire, herbivory) are thought to be important in regulating woody cover, but perceptions differ on which of these are the primary drivers of savanna structure. Here we show, using data from 854 sites across Africa, that maximum woody cover in savannas receiving a mean annual precipitation (MAP) of less than approximately 650 mm is constrained by, and increases linearly with, MAP. These arid and semi-arid savannas may be considered 'stable' systems in which water constrains woody cover and permits grasses to coexist, while fire, herbivory and soil properties interact to reduce woody cover below the MAP-controlled upper bound. Above a MAP of approximately 650 mm, savannas are 'unstable' systems in which MAP is sufficient for woody canopy closure, and disturbances (fire, herbivory) are required for the coexistence of trees and grass. These results provide insights into the nature of African savannas and suggest that future changes in precipitation may considerably affect their distribution and dynamics.
- Published
- 2005
38. Ideias, instituições e coalizões: as razões do fracasso da política industrial lulista
- Author
-
MICHELLI GONÇALVES STUMM, WELLINGTON NUNES, and RENATO PERISSINOTTO
- Subjects
Política industrial ,governos Lula ,abordagem ideacional ,Economics as a science ,HB71-74 - Abstract
RESUMO Este artigo trata da política industrializante dos governos Lula, com o objetivo de explicar por que ela fracassou. Isso é feito em três momentos distintos. Primeiramente, tratamos das ideias que orientaram as políticas industriais do período. Em segundo lugar, mostramos, com base em conjunto sintético de informações, que os objetivo pretendidos, em sua maioria, não foram alcançados. Finalmente, analisamos o insucesso dessas políticas como base na ausência de viabilidades (intelectual, administrativa e política) do conjunto de ideias que norteou o empreendimento.
- Published
- 2019
- Full Text
- View/download PDF
39. Abiotic and herbaceous vegetational characteristics of an arid rangeland in Kenya
- Author
-
Wellington N. Ekaya, CN Karue, Jenesio I. Kinyamario, and research funded by the UNEP Project on climate change and the productivity of tropical grasslands
- Subjects
Abiotic component ,Hydrology ,Ecology ,Standing crop ,Environmental science ,Animal Science and Zoology ,Relative humidity ,Quadrat ,Herbaceous plant ,Rangeland ,Arid ,Structure and function - Abstract
A two-year study was conducted with an overall objective of characterising the structure and function of an arid rangeland in Kenya. A plot measuring 100 x 100m was used for this study. Data on rainfall and temperature were recorded at the plot site whereas data on evaporation rates and relative humidity were obtained from the meteorological office near the study site. Herbaceous aboveground material was sampled at monthly intervals using a rectangular 0.25m2 quadrat frame. Clipped material was separated by species and classified dead or live by physical examination. A 5cm diameter metal soil corer was used to sample belowground plant material, at monthly intervals. The sampled material was washed with running water over 2mm sieves and classified dead or live using the vital staining technique. All weights and calculations were based on organic weight. Total aboveground standing crop ranged from 84.6g m-2 to 295.4g m-2, with a mean of 162.3 60.6g m-2. Mean monthly aboveground standing crop for 1992 and 1993 was 142.8 53.8 and 178.5 63.3g m-2 respectively. The two values were significantly different (p0.01) in the mean belowground dead material yield between 1992 and 1993. In 1992, annual NPP was 439.2g m-2, giving a net primary productivity of 1.22g m-2day-1. Monthly NPP ranged from 17.2g m-2 to 90.1g m-2. In 1993, annual NPP was 944.5g m-2, equivalent to a net primary productivity of 2.62g m-2day-1. Monthly NPP was between 27.4g m-2 and 548.6g m-2. Over the 19921993 period, NPP was 1 383.7g m-2, equivalent to a productivity of 1.92g m-2day-1. Trends in monthly NPP closely followed the trend in rainfall. On the whole, herbaceous vegetation production and productivity were episodic in nature and closely linked to rainfall. The high primary productivity puts arid and semi-arid rangelands under sharp focus as CO2 sinks, whose role in the amelioration of greenhouse effect could be more important than is currently appreciated. Keywords: climatic elements; aboveground biomass; belowground biomass; primary productivity African Journal of Range & Forage Science 2001, 18(2&3): 117-124
- Published
- 2001
40. Botanical and Chemical Composition of Livestocks Diets on a Semi-Arid Rangeland
- Author
-
Wellington N. Ekaya, CN Karue, and T Tadingar
- Subjects
Multidisciplinary ,Agronomy ,business.industry ,Agroforestry ,Management of Technology and Innovation ,Environmental science ,Livestock ,Rangeland ,business ,Chemical composition ,Arid - Published
- 1997
41. Wreck removal: an analysis between Brazilian maritime law and the Nairobi international convention on the removal of wrecks
- Author
-
Wellington Nogueira Camacho
- Subjects
Commerce ,HF1-6182 ,Shipment of goods. Delivery of goods ,HF5761-5780 ,Private international law. Conflict of laws ,K7000-7720 ,Naval Science - Abstract
O presente trabalho possui como objetivo realizar uma análise comparativa entre a Convenção sobre Remoção de Destroços e a Lei nº 7.542/1986, que trata do mesmo assunto em águas jurisdicionais brasileiras, ressaltando a necessidade de garantir a preservação do meio ambiente marinho e a existência de seguros de risco e outras garantias financeiras para contemplar a remoção de destroços, em face de um acidente marítimo.
- Published
- 2021
42. A elite salarial do funcionalismo público federal
- Author
-
Wellington Nunes and José Teles Mendes
- Subjects
burocracia ,elite salarial ,remunerações no serviço público ,reforma administrativa ,reforma do Estado ,Political institutions and public administration (General) ,JF20-2112 - Abstract
Este artigo tem como objetivo a identificação e análise da elite salarial do funcionalismo público federal brasileiro. Por elite salarial, o trabalho compreende as categorias com maiores salários do Estado. Primeiro, a partir de dados da Relação Anual de Informações Sociais (Rais), identificamos as ocupações mais bem remuneradas do conjunto do serviço público no ano de 2018, analisando suas características principais e em quais poderes e esferas se concentravam. Em seguida, utilizando dois critérios de corte distintos, a mediana salarial do Judiciário e o salário de ministro do Supremo Tribunal Federal (STF) em 2018, verificamos também a evolução salarial da parcela com remunerações mais altas do serviço público federal nos últimos 20 anos. Em particular, focamos no estudo dos chamados supersalários, isto é, aqueles que superam a remuneração de juiz do STF. Demonstramos que, apesar de o poder mais numeroso em termos de vínculos empregatícios ser o Executivo, é o Judiciário que concentra a maior parte das ocupações da chamada elite salarial. Além disso, concluímos que, embora variável ao longo dos anos, o quantitativo dos chamados supersalários é menor do que o esperado no âmbito federal. Ainda assim, gera impacto fiscal relevante. Por fim, comparamos os achados à Proposta de Emenda Constitucional (PEC) 32/2020, fazendo sugestões para a construção de um projeto de reforma administrativa mais eficiente no combate a privilégios.
- Published
- 2021
- Full Text
- View/download PDF
43. Indigenous Knowledge: The Basis of The Maasai Ethnoveterinary Diagnostic Skills
- Author
-
Jacob, Miaron O., primary, Farah, Kassim O., additional, and Ekaya, Wellington N., additional
- Published
- 2004
- Full Text
- View/download PDF
44. Educação profissional e tecnológica: contribuições da pesquisa para a compreensão da constituição docente
- Author
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Vidica Bianchi Bianchi, Adriano Ferreira da Silva Neto, wellington Nascimento Silva, and Eva Teresinha de Oliveira Boff
- Subjects
currículo ,constituição dos professores ,prática pedagógica ,Education (General) ,L7-991 ,Special aspects of education ,LC8-6691 - Abstract
Este estudo teve por finalidade realizar um levantamento do tipo “estado da arte” de artigos publicados no site de periódicos da Coordenação de Aperfeiçoamento de Profissionais de Ensino Superior (CAPES) entre 2017 a 2019. O objetivo é analisar o processo de constituição do professor, suas adversidades e desafios para atuar na Educação Profissional e Tecnológica (EPT), bem como investigar acerca do que vem sendo publicado em relação a temática currículo e formação de professores no contexto da educação profissional. Trata-se de uma revisão sistemática da literatura, cuja análise teve como base os argumentos de Moraes e Galiazzi (2007) sobre análise textual discursiva (ATD). Para a realização foram utilizados os descritores: “currículo” and “formação de professores” and “educação profissional”; “currículo” and “constituição do professor” and “educação profissional”; “currículo” and “docente da educação profissional”. Ao total, foram encontrados 657 artigos, no entanto, somente seis se aproximaram dos objetivos deste estudo e dos critérios estabelecidos. Os resultados da pesquisa mostram que a EPT tem se configurado como importante campo de pesquisa, e que existe um crescimento de produções acerca do assunto, no entanto, com poucos escritos no que se refere à constituição do professor da EPT.
- Published
- 2020
- Full Text
- View/download PDF
45. Assessment of the performance of exotic and indigenous tree and shrub species for rehabilitating saline soils of Northern Kenya
- Author
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Olukoye, Godfrey A., primary, Wamicha, Wellington N., additional, and Kinyamario, Jenesio I., additional
- Published
- 2003
- Full Text
- View/download PDF
46. Land Use and Spatial Distribution of Two Gum and Incense Producing Tree Species in the Blue-nile Valley of Wogidi District, Ethiopia
- Author
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Turi, Chane G., primary, Musimba, Nashon K. R., additional, Ekaya, Wellington N., additional, and Farah, Kassim O., additional
- Published
- 2003
- Full Text
- View/download PDF
47. Effect of Moisture Availability on Nitrogen and Phosphorus Uptake by Plants Under Semi-arid Soil Conditions
- Author
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Macharia, Peter N., primary and Ekaya, Wellington N., additional
- Published
- 2002
- Full Text
- View/download PDF
48. Biodiversity characteristics of small high‐altitude tropical man‐made reservoirs in the Eastern Rift Valley, Kenya
- Author
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Mwaura, Francis, primary, Mavuti, Kenneth M., additional, and Wamicha, Wellington N., additional
- Published
- 2002
- Full Text
- View/download PDF
49. Woodlands and Livelihoods of African Pastoralists: The Massai of Kajiado, Kenya
- Author
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Ekaya, Wellington N., primary and Kinyamario, Jenesio I., additional
- Published
- 2001
- Full Text
- View/download PDF
50. Maasai Indigenous Knowledge on Range Vegetation Analysis, Utilization and Management
- Author
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Macharia, Peter N., primary and Ekaya, Wellington N., additional
- Published
- 2001
- Full Text
- View/download PDF
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