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1.
Ecol Appl ; 32(1): e02483, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34674336

RESUMO

Landscape fragmentation and habitat loss at multiple scales directly affect species abundance, diversity, and productivity. There is a paucity of information about the effect of the landscape structure and diversity on honey bee colony strength in Africa. Here, we present new insights into the relationship between landscape metrics such as patch size, shape, connectivity, composition, and configuration and honey bee (Apis mellifera) colony strength characteristics. Remote-sensing-based landscape variables were linked to honey bee colony strength variables in a typical highly fragmented smallholder agroecological region in Kenya. We examined colonies in six sites with varying degrees of land degradation during the period from 2017 to 2018. Landscape structure was first mapped using medium resolution bitemporal Sentinel-1 and Sentinel-2 satellite imagery with an optimized random forest model. The influence of the surrounding landscape matrix was then constrained to two buffer distances, i.e., 1 km representing the local foraging scale and 2.5 km representing the wider foraging scale around each investigated apiary and for each of the six sites. The results of zero-inflated negative binomial regression with mixed effects showed that lower complexity of patch geometries represented by fractal dimension and reduced proportions of croplands were most influential at local foraging scales (1 km) from the apiary. In addition, higher proportions of woody vegetation and hedges resulted in higher colony strength at longer distances from the apiary (2.5 km). Honey bees in moderately degraded landscapes demonstrated the most consistently strong colonies throughout the study period. Efforts towards improving beekeeper livelihoods, through higher hive productivity, should target moderately degraded and heterogeneous landscapes, which provide forage from diverse land covers.


Assuntos
Ecossistema , Meio Ambiente , Animais , Abelhas , Quênia
2.
Trop Anim Health Prod ; 44(3): 657-64, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21833678

RESUMO

Nematode infections are a serious constraint to pig production, especially where free range pig keeping is practiced. This study investigated the epidemiology of nematodes in free range pigs in Busia District, Kenya. Three hundred and six pigs from 135 farms were sampled for faeces that were analysed for nematode eggs per gram (EPG) of faeces using the McMaster technique. The nematode eggs were also identified to genus and species based on morphology. A questionnaire on risk factors was also administered to the pig owners. The overall prevalence and mean nematode EPG were 84.2% and 2,355, respectively. The nematode eggs were identified as those belonging to Oesophagostomum spp. (75%), Strongyloides ransomi (37%), Ascaris suum (18%), Metastrongylus spp. (11%), Trichuris suis (7%) and Physocephalus sexalatus (3%). The prevalence of nematodes was positively correlated (p < 0.05) with the amount of rainfall in the division of the pigs' origin (all nematodes except S. ransomi). The prevalence of nematodes was also associated with the age of the pigs. A lower burden of nematodes was associated (p < 0.05) with a history of deworming (A. suum) and the provision of night housing (S. ransomi and Metastrongylus spp.). In conclusion, this study has provided information on nematode infections and the associated risk factors for free range pigs in Busia District, which can be used when implementing integrated control measures.


Assuntos
Nematoides/fisiologia , Infecções por Nematoides/veterinária , Doenças dos Suínos/epidemiologia , Fatores Etários , Criação de Animais Domésticos/métodos , Animais , Estudos Transversais , Meio Ambiente , Fezes/parasitologia , Feminino , Quênia/epidemiologia , Masculino , Análise Multivariada , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas/veterinária , Prevalência , Fatores de Risco , Fatores Sexuais , Especificidade da Espécie , Suínos , Doenças dos Suínos/parasitologia
3.
J Acquir Immune Defic Syndr ; 66 Suppl 1: S3-12, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24732819

RESUMO

BACKGROUND: Cross-sectional population-based surveys are essential surveillance tools for tracking changes in HIV epidemics. In 2007, Kenya implemented the first AIDS Indicator Survey [Kenya AIDS Indicator Survey (KAIS) 2007)], a nationally representative, population-based survey that collected demographic and behavioral data and blood specimens from individuals aged 15-64 years. Kenya's second AIDS Indicator Survey (KAIS 2012) was conducted to monitor changes in the epidemic, evaluate HIV prevention, care, and treatment initiatives, and plan for an efficient and effective response to the HIV epidemic. METHODS: KAIS 2012 was a cross-sectional 2-stage cluster sampling design, household-based HIV serologic survey that collected information on households as well as demographic and behavioral data from Kenyans aged 18 months to 64 years. Participants also provided blood samples for HIV serology and other related tests at the National HIV Reference Laboratory. RESULTS: Among 9300 households sampled, 9189 (98.8%) were eligible for the survey. Of the eligible households, 8035 (87.4%) completed household-level questionnaires. Of 16,383 eligible individuals aged 15-64 years and emancipated minors aged less than 15 years in these households, 13,720 (83.7%) completed interviews; 11,626 (84.7%) of the interviewees provided a blood specimen. Of 6302 eligible children aged 18 months to 14 years, 4340 (68.9%) provided a blood specimen. Of the 2094 eligible children aged 10-14 years, 1661 (79.3%) completed interviews. CONCLUSIONS: KAIS 2012 provided representative data to inform a strategic response to the HIV epidemic in the country.


Assuntos
Síndrome da Imunodeficiência Adquirida/epidemiologia , Soropositividade para HIV/epidemiologia , Inquéritos Epidemiológicos/métodos , Síndrome da Imunodeficiência Adquirida/imunologia , Adolescente , Adulto , Contagem de Linfócito CD4 , Criança , Pré-Escolar , Aconselhamento , Estudos Transversais , Feminino , Soropositividade para HIV/imunologia , Humanos , Lactente , Entrevistas como Assunto , Quênia/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Inquéritos e Questionários , Adulto Jovem
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