80 results on '"Pezo, D."'
Search Results
2. Repeated embryo collection and interspecies transfer in alpacas and llamas during non-breeding season
- Author
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Pacheco J, Tollig S, Von Walter AW, Pezo D, and Velez V
- Subjects
embryo transfer ,alpaca ,llama ,reproductive season ,interspecies ,Reproduction ,QH471-489 ,Zoology ,QL1-991 - Abstract
Sexual behavior evaluation was evaluated, collecting and interspecies embryo transfer inter species in llamas and alpacas during non-breeding season, 10 and 10 donor alpacas llamas, alpacas and 20 receiving 20 llamas, 5 alpacas and 5 llamas males were used. Sexual behavior by libido in males and acceptance of female to male in the presence of a dominant follicle was evaluated, the collection of embryos simple ovulation by non-surgical technique was performed and the fresh embryos are transferred directly into the horn left. It was observed that only 40% of alpaca accept the male and female in all cases had to use two males for mating, but all llama males mounted on the first attempt and accepted all females breeding. Embryos were collected at 25 and 60% of alpacas and llamas washes respectively, all were grade 1 embryos transferable; the embryo transfer fertility evaluated by ultrasound at 25 days was 100 and 41.6% respectively for donor alpaca and llama, however ultrasound evaluation at 60 days fertility was 50 and 25% respectively for donor alpaca and llama. We conclude that there is greater reproductive seasonality in alpaca regard to llamas, all were grade 1 embryos collected, fertility evaluated by ultrasound 25 days down to 60 days, demonstrating embryonic mortality, possibly due to the non-breeding season of both species.
- Published
- 2015
- Full Text
- View/download PDF
3. Diminution of aflatoxin B1 production caused by an active packaging containing cinnamon essential oil
- Author
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Manso, S., Pezo, D., Gómez-Lus, R., and Nerín, C.
- Published
- 2014
- Full Text
- View/download PDF
4. Conflicts between Conservation Agriculture and Livestock over the Utilisation of Crop Residues
- Author
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Mueller, J. P., Pezo, D. A., Benites, J., Schlaepfer, N. P., García-Torres, Luis, editor, Benites, José, editor, Martínez-Vilela, Armando, editor, and Holgado-Cabrera, Antonio, editor
- Published
- 2003
- Full Text
- View/download PDF
5. Arboles forrajeros de tres regiones ganaderas de Chiapas, Mexico: usos y caracteristicas nutricionales
- Author
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Pinto-Ruiz, R., Hernández, D., Gómez, H., Cobos, M.A., Quiroga, R., and Pezo, D.
- Published
- 2010
6. Identification and migration of degradation compounds from irradiation of multilayer polyamide 6 films for meat foodstuffs and cheese
- Author
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Félix, J. S., Monteiro, M., Manzoli, J. E., Padula, M., Pezo, D., Romero, J., and Nerín, C.
- Published
- 2008
- Full Text
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7. Design of a method for generation of gas-phase hydroxyl radicals, and use of HPLC with fluorescence detection to assess the antioxidant capacity of natural essential oils
- Author
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Pezo, D., Salafranca, J., and Nerín, C.
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- 2006
- Full Text
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8. A primary Corynebacterium pseudotuberculosis low dose infection in alpacas ( Lama pacos) protects against a lethal challenge exposure
- Author
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Braga, W., Schul, S., Nuñez, A., Pezo, D., and Franco, E.
- Published
- 2007
- Full Text
- View/download PDF
9. Promoting intake of Cratylia argentea as a dry season supplement for cattle grazing Hyparrhenia rufa in the subhumid tropics
- Author
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Ibrahim, M., Franco, M., Pezo, D. A., Camero, A., and Araya, J. L.
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- 2001
- Full Text
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10. Osmolarity effect of endosmotic response on epidymis sperm and ejaculated alpaca (Vicugna pacos)
- Author
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Pacheco Curie, J. I., Mamani Cato, Rubén Herberht, Franco, F., Zea, O., Pezo, D., and Vélez, V.
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Espermatozoides ,Plasma seminal ,Endósmosis ,Tecnología de modificación genética ,Alpaca - Abstract
3 Páginas El test hipoosmótico permite evaluar la integridad de la membrana plasmática del espermatozoide. Con el objetivo de evaluar el efecto de la osmolaridad de la solución y la presencia o no de plasma seminal sobre la respuesta al test hipoosmótico en espermatozoides de alpaca se utilizaron 6 machos adultos. Se colectaron espermatozoides mediante vagina artificial y desviación de los conductos deferentes, se utilizaron 3 soluciones hipoosmóticas calculadas a 50, 100 y 150 mOsmoly se incubo 0.1 mL de muestra en 0.9 mL de cada solución hipoosmótica a 37°C por 30 minutos evaluando 200 espermatozoides para determinar respuesta endosmótica. La vitalidad se determinó mediante tinción de eosina-nigrosina. Se encontró diferencia estadística entre las tres soluciones hipoosmóticas (p≤0.05), siendo la mejor respuesta endosmótica de espermatozoides con plasma seminal incubados en solución hipoosmótica1de 50 mOsmol. INTRODUCCIÓN. MATERIALES Y MÉTODOS. RESULTADOS. DISCUSIÓN. CONCLUSIÓN. REFERENCIAS
- Published
- 2014
11. Descripción anátomo patológica y microbiológica de la osteomielitis del maxilar inferior en crías de alpacas
- Author
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Pezo, D., primary, Rosadio, R., additional, Braga, W., additional, and Alarcon, V., additional
- Published
- 2016
- Full Text
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12. Descripción anátomo patológica y microbiológica de la osteomielitis del maxilar inferior en crías de alpacas
- Author
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Pezo, D., Rosadio, R., Braga, W., Alarcon, V., Pezo, D., Rosadio, R., Braga, W., and Alarcon, V.
- Abstract
Se describe la osteomielitis del maxilar inferior en 3 crías de alpacas entre 20 y 45 días de edad, mediante estudios clínicos, patológicos, histopatológicos, y microbiológicos, con el objetivo de caracterizar las lesiones y describir los agentes etiológicos. Clínicamente las crías mostraron escaso desarrollo y bajo peso con respecto a su edad, decaimiento y depresión; a la palpación hubo engrosamiento y tumoración con fístulas internas entre la base de los premolares y molares que comunicaban la cavidad bucal con la lesión ósea con material purulento entremezclado con pasto. Las crías murieron durante el desarrollo de la enfermedad y a la necropsia se hallaron lesiones de hiperostosis, rarefacción, necrosis e involucro con secuestro, diagnosticados visualmente y por palpación. La hiperostosis severa fue la lesión histológica más frecuente, caracterizada por áreas de necrosis licuefactiva con abundantes polimorfa nuclear, disgregación del tejido óseo y presencia de tejido conectivo fibroso alrededor de la lesión. Las bacterias halladas fueron A. pyogenes, S. aureus, S. pyogenes, S. viridans C. pseudotuberculosis, y F. necrophorus. Se concluye que la osteomielitis en crías es de curso rápido que abarca un grado variable de fibrosis de la medula y es polimicrobiana.
- Published
- 2015
13. Risk Factors for African Swine Fever in Smallholder Pig Production Systems in Uganda
- Author
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Dione, M. M., primary, Akol, J., additional, Roesel, K., additional, Kungu, J., additional, Ouma, E. A., additional, Wieland, B., additional, and Pezo, D., additional
- Published
- 2015
- Full Text
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14. Risk Factors for African Swine Fever in Smallholder Pig Production Systems in Uganda.
- Author
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Dione, M. M., Akol, J., Roesel, K., Kungu, J., Ouma, E. A., Wieland, B., and Pezo, D.
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AFRICAN swine fever ,PANDEMICS ,BIOSECURITY ,LIVESTOCK productivity ,SECONDARY schools - Abstract
Smallholder pig production in Uganda is constrained by poor management and high disease burden, with African swine fever ( ASF) being one of the most important contributors. However, data to develop appropriate evidence-based disease mitigating interventions along the pig value chain are lacking. This study aimed at determining risk factors associated with the occurrence of outbreaks of ASF in selected districts. A cross-sectional survey of 1195 pig-keeping households in three districts was carried out between April and July 2013. Households were classified into one of three value chain domains ( VCDs) based on where the production was located and where most of the products were sold: rural-rural (R-R), rural-urban (R-U) and urban-urban (U-U). Findings revealed that crop farming is the most common primary activity in the R-R and R-U VCDs, while pig keeping was the most common primary activity in the U-U VCDs. Pigs are mostly kept tethered or left to roam in the R-R and R-U VCDs, while in the U-U VCDs, they are mostly confined in corrals. Nearly 20% of the farmers whose farms were hit by an ASF outbreak subsequently sold all their pigs (healthy and sick) to the market in panic. Factors that positively correlated with recent ASF outbreaks were prompt disposal of dead pigs on farms ( P < 0.001, OR = 2.3), wild animals present in the village ( P < 0.001, OR = 1.7) and farmers sourcing drugs from stockists ( P < 0.001, OR = 1.6); while protective factors were the presence of perimeter fences ( P = 0.03, OR = 0.5), attendance of farmers at secondary-school level and above ( P < 0.001, OR = 0.6), routine cleaning of the pig pens ( P < 0.001, OR = 0.6) and pigs being the only livestock kept by farmer ( P = 0.01, OR = 0.7). Given the current situation, there is a need to raise awareness among farmers and other value chain actors of biosecurity measures and create incentives for farmers to report ASF cases. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
15. Serological and molecular investigation for brucellosis in swine in selected districts of Uganda
- Author
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Erume, J., primary, Kristina, R., additional, Dione, M. M., additional, Ejobi, F., additional, Mboowa, G., additional, Kungu, J., additional, Akol, Joyce, additional, Pezo, D., additional, El-Adawy, H., additional, Melzer, F., additional, Elschner, M., additional, Neubauer, H., additional, and Grace, D., additional
- Published
- 2015
- Full Text
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16. Exceeding expectations
- Author
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Pezo, D., Cruz, J., Hernández, K., Villeda, R., Pezo, D., Cruz, J., Hernández, K., and Villeda, R.
- Abstract
The “Degraded Pastures” project in Central America has had an impact that has extended far beyond the duration and scope of the project. This is because the joint learning process that it established motivated the participants to continue working together, and also motivated other organisations, both public and private, to join or support them.
- Published
- 2010
17. Better livestock management in Guatemala
- Author
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Piniero, M., Pezo, D., Cruz, J., Piniero, M., Pezo, D., and Cruz, J.
- Abstract
Working closely with farmer groups of different sizes in Central America, the project described in this article was aimed at rehabilitating degraded pastureland. Various participatory processes were followed, to encourage farmers to examine their situation and prioritise problems to work on. The learning process is described and analysed, and questions about how best to collaborate with farmers are posed
- Published
- 2006
18. Comparison of Animal Productivity and Profitability Between a Silvopastoral System (Brachiaria brizantha Associated with Leucaena leucocephala) and a Conventional System (B. brizantha+Chicken Manure)
- Author
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Jimenez-Tr, J.A., additional, Ibrahim, M., additional, Pezo, D., additional, Guevara-He, F., additional, Gomez-Cast, H., additional, Nahed-Tora, J., additional, and Pinto-Ruiz, R., additional
- Published
- 2011
- Full Text
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19. Grass-legume balance under grazing in the humid tropics of Costa Rica
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Ibrahim, M.A., 't Mannetje, L., and Pezo, D.
- Subjects
Agronomie ,Life Science ,Agronomy - Published
- 1994
20. DETERMINACION DE METALES PESADOS BIOACUMULABLES EN ESPECIES ICTICAS DE CONSUMO HUMANO EN LA AMAZONIA PERUANA
- Author
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Roberto Pezo-D., H. Paredes-A., and Nora Yoni Bendayán-Acosta
- Abstract
En el presente trabajo se reportan resultados de los análisis químicos realizados en 26 especies de peces de consumo humano, de los cuales 19 son de mayor demanda en la ciudad de Iquitos. Se han estudiado cuatro metales pesados bioacumulables como Mercurio, Cadmio, Plomo y Cobre.Se han muestreado especies de tres ríos diferentes; Nanay, Ucayali y Amazonas. Las concentraciones en su mayoría son menores que los límites establecidos intemacionalmente para pescado y productos pesqueros a excepción del “Dorado” (Brachyplatistoma fiavicans).
- Published
- 1992
- Full Text
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21. ESTUDIO DE IMPACTO AMBIENTAL DEL PROYECTO DE RELLENO SANITARIO EN LA COMUNIDAD DE MORALILLO, PROPUESTO PARA LA CIUDAD DE IQUITOS, LORETO-PERÚ
- Author
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CORREA-TANG, Melba Del Rocío, primary, MONTALVÁN-I., Bertha, additional, PEZO-D., Roberto, additional, and VERDI-O., Lorgio, additional
- Published
- 2007
- Full Text
- View/download PDF
22. DETERMINACION DE METALES PESADOS BIOACUMULABLES EN ESPECIES ICTICAS DE CONSUMO HUMANO EN LA AMAZONIA PERUANA
- Author
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PEZO-D., Roberto, primary, PAREDES-A., H., additional, and BENDAYÁN-ACOSTA, Nora Yoni, additional
- Published
- 2006
- Full Text
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23. Food-Feed Systems in Asia - Review -
- Author
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Devendra, C., primary, Sevilla, C., additional, and Pezo, D., additional
- Published
- 2001
- Full Text
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24. Evaluation of early reproductive performance in the postpartum alpaca by progesterone concentrations
- Author
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Bravo, P.Walter, primary, Pezo, D., additional, and Alarcon, V., additional
- Published
- 1995
- Full Text
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25. The decision-making process in the adoption of Gliriddiasepium protein banks by double purpose producers in Rivas, Nicaragua.
- Author
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López, M., Pezo, D., and Prins, J. Moray C.
- Subjects
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GLIRICIDIA sepium , *SILVOPASTORAL systems , *DECISION making , *LIVESTOCK farms , *FORAGE plants , *MANAGEMENT , *ECOLOGY ,ENVIRONMENTAL aspects - Abstract
This paper analyzes the process for the adoption of Gliricidia sepium protein banks by members of the Livestock Farmers Association of Rivas, Nicaragua (ASOGARI), who participated of the Silvopastoral Systems Development Project implemented with the technical support of the Center for Research on Sustainable Agriculture Production Systems (CIPAV) and the Nicaraguan Forestry Project (PROFOR). A structured survey was administered to 100 livestock farmers chosen at random among ASOGARI members to define the main typologies and if there are differences among them for the potential adoption of protein bank technologies. For the analysis of factors affecting the adoption of protein banks, survey data was analyzed applying a binary model based on the assumption that adoption depends on attributes and requirements of a given technology. Additionally, to identify those variables affecting adoption, data was analyzed with a logistic multiple regression model known as Tobit. Among the factors that affected more the adoption of protein banks was the access to technical assistance, contribution of livestock to farm income, availability of labor, years of experience in livestock and school attendance, and access to incentives for investment in livestock. The decision making process for the adoption of protein banks included biophysical (e.g., availability of flat and fertile land, access to seeds or planting materials, climatic conditions at planting), and socio-economic conditions (e.g. availability of family and/or hired labor, availability of cash or incentives for planting, prices of milk and supplements), as well as environmentally favorable farmers attitude. The rationale applied for the adoption of G.. sepium protein banks indicates that farmers utilized the learnings obtained through training, as most criteria considered by farmers are the ones researchers have identified as constraints or opportunities for the successful application of protein bank technologies. [ABSTRACT FROM AUTHOR]
- Published
- 2007
26. El proceso de toma de decisiones en la adopción de bancos de proteína de Gliriddiasepium por productores de doble propósito en Rivas, Nicaragua.
- Author
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López, M., Pezo, D., and Prins, J. Moray C.
- Subjects
- *
GLIRICIDIA sepium , *SILVOPASTORAL systems , *DECISION making , *LIVESTOCK farms , *FORAGE plants , *MANAGEMENT , *ECOLOGY ,ENVIRONMENTAL aspects - Abstract
Este artículo analiza el proceso de adopción de bancos de proteína de Gliricidia sepium por miembros de la Asociación de Ganaderos de Rivas, Nicaragua (ASOGARI), quienes participaron en el Proyecto de Desarrollo de Sistemas Silvopastoriles implementado con la asistencia técnica del Centro para la Investigación en Sistemas Agropecuarios de Producción Sostenible (CIPAV) y el Proyecto Forestal de Nicaragua (PROFOR). Se realizó una encuesta estructurada a 100 ganaderos elegidos al azar entre los miembros de ASOGARI, con el fin de definir las principales tipologías y si existían diferencias entre ellos para la adopción potencial de la tecnología de bancos de proteína. Para el análisis de los factores que afectan la adopción de los bancos de proteína, se analizaron los datos de la encuesta aplicando un modelo binario basado en la premisa de que la adopción depende de los atributos y requerimientos de una tecnología dada. Además, para identificar las variables que afectaban la adopción se analizaron los datos mediante un modelo logístico de regresión múltiple conocido como Tobit. Entre los factores que más afectaron la adopción de los bancos de proteína estuvieron el acceso a la asistencia técnica, la contribución del ganado al ingreso de la finca, la disponibilidad de mano de obra, los años de experiencia en la ganadería y la escolaridad, y el acceso a incentivos para la inversión en la ganadería. El proceso de toma de decisiones para la adopción de los bancos de proteína incluyó las condiciones biofísicas (por ejemplo, la disponibilidad de tierra llana y fértil, el acceso a la semilla o materiales de siembra, las condiciones climáticas en el momento de la siembra) y socioeconómicas (por ejemplo, la disponibilidad de mano de obra familiar y/o contratada, la disponibilidad de efectivo o incentivos para la siembra, los precios de la leche y los suplementos), así como una actitud favorable hacia el medio ambiente en los campesinos. El fundamento aplicado para la adopción de los bancos de proteína de G sepium indica que los campesinos utilizaron las enseñanzas obtenidas a través de la capacitación, ya que la mayoría de los criterios considerados por los productores son los identificados por los investigadores como limitaciones u oportunidades para la aplicación exitosa de la tecnología de bancos de proteína. [ABSTRACT FROM AUTHOR]
- Published
- 2007
27. Impacto bioeconómico de la degradación de pasturas en tincas de doble propósito en El Chai, Peten, Guatemala.
- Author
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Betancourt, Herty, Pezo, D. A., Cruz, J., and Beer, J.
- Subjects
- *
PASTURES , *BIOECONOMICS , *ENVIRONMENTAL degradation , *ENVIRONMENTAL degradation research , *ECOLOGY , *ECONOMICS ,ENVIRONMENTAL aspects ,DEVELOPING countries - Abstract
Al menos 6,3 millones de hectáreas en América Central están cubiertas por pastizales degradados, y esas áreas aumentan porque las tasas anuales de renovación son menores que las de degradación. Este estudio es un esfuerzo por estimar el impacto bioeconómico de la degradación de los pastos en un área de 720 km², que representa la zona piloto del proyecto "Degradación de pasturas CATIE/NORUEGA" en Peten, Guatemala. Se utilizó una combinación de estimados del área de la tierra, realizados mediante la aplicación de métodos de SIG a imágenes de satélite de alta resolución; mediciones directas de la disponibilidad, la composición botánica y la calidad del pasto en 41 potreros que presentaban diferentes niveles de degradación de las pasturas; y predicciones del comportamiento del ganado bovino a través del modelo de simulación LIFE-SIM, para estimar la reducción de la producción de leche y carne, y su valor económico debido a la degradación de las pasturas. Los estimados mostraron que el 65% del área estaba cubierta por pasturas y el 70% de estas presentaba degradación de moderada a muy severa. El rendimiento de leche por vaca disminuyó en 7-34% cuando la degradación de las pasturas se incrementó de ligera a muy severa, y los valores equivalentes para la producción de carne fueron 13-43%. Se estima que debido a la degradación de los pastos la zona piloto está perdiendo hasta 3,4 millones de dólares por año en productos animales en sus 41 695 hectáreas de pastos, o alrededor de US$ 82,50 por hectárea por año. [ABSTRACT FROM AUTHOR]
- Published
- 2007
28. Modulation Imperfections In IS54 Dual Mode Cellular Radio
- Author
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Brillant, A., primary and Pezo, D., additional
- Full Text
- View/download PDF
29. Participatory evaluation of pastures with criteria of small and medium livestock producers.
- Author
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Cruz, J., Piniero, Maricel, and Pezo, D.
- Subjects
- *
LIVESTOCK productivity , *LIVESTOCK systems , *PASTURES , *FARMERS - Abstract
Incorporation of local people's knowledge has proven to be important and crucial in implementing research and development projects. This paper presents a participatory approach using farmers' knowledge in evaluating improved pastures in EL Chal, Peten, Guatemala. On-farm experiments of five improved pastures selected by farmers were materialized in farmers' fields to elicit local criteria for pasture evaluation. Two evaluations based on seasonal changes were undertaken to see if farmers' indicators would vary. Farmers' evaluations were tabulated and compared using economic variable particularly land tenancy: private owner and leaseholder. Results show that both groups of farmers use a number of criteria in evaluating improved pastures which go beyond the pastures growth habit. These include animal preference, resistance to dry period and pests and its ability to compete with weeds, among others. The results also showed that although farmers' indicators remain about the same in the two seasons, their ranking of categories changed. On the first evaluation, farmers emphasized on indicators that are observable (color, vigor) while on the second evaluation they focused more on pastures overall performance (resistance to limiting factors). Furthermore, the biophysical components of the production system as well as the socio economic condition of farmers affect their evaluation. Farmers whose farms are located in undulated area gave more importance on tolerance to drought and ability to grow in sloping areas while those who have farms in flat areas emphasized on resistance to pests and water logging, and shade tolerance. Small-scale farmers tend to focus on pasture's ability to compete with weeds, while this is not that important for medium scale producers. Taking into consideration culturally significant indicators can help implementing projects and transferring technologies that people can identify with and use within their limited environment. [ABSTRACT FROM AUTHOR]
- Published
- 2007
30. Evaluación participativa de pastos con criterios de pequeños y medianos productores ganaderos.
- Author
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Cruz, J., Piniero, Maricel, and Pezo, D.
- Subjects
- *
AGRICULTURAL development , *PASTURE management , *FARMERS , *SOCIOECONOMIC factors , *WEED risk assessment - Abstract
Incorporation of local people's knowledge has proven to be important and crucial in implementing research and development projects. This paper presents a participatory approach using farmers' knowledge in evaluating improved pastures in EL Chai, Peten, Guatemala. On-farm experiments of five improved pastures selected by formers were materialized in farmers' fields to elicit local criteria for pasture evaluation. Two evaluations based on seasonal changes were undertaken to see if farmers' indicators would vary. Farmers' evaluations were tabulated and compared using economic variable particularly land tenancy: private owner and leaseholder. Results show that both groups of farmers use a number of criteria in evaluating improved pastures which go beyond the pastures growth habit. These include animal preference, resistance to dry period and pests and its ability to compete with weeds, among others. The results also showed that although farmers' indicators remain about the same in the two seasons, their ranking of categories changed. On the first evaluation, farmers emphasized on indicators that are observable (color, vigor) while on the second evaluation they focused more on pastures overall performance (resistance to limiting factors). Furthermore, the biophysical components of the production system as well as the socioeconomic condition of farmers affect their evaluation. Farmers whose farms are located in undulated area gave more importance on tolerance to drought and ability to grow in sloping areas while those who have farms in flat areas emphasized on resistance to pests and water logging, and shade tolerance. Small-scale farmers tend to focus on pasture's ability to compete with weeds, while this is not that important for medium scale producers. Taking into consideration culturally significant indicators can help implementing projects and transferring technologies that people can identify with and use within their limited environment. [ABSTRACT FROM AUTHOR]
- Published
- 2007
31. Assessment of the bioeconomical impact of pasture degradation in dual purpose livestock far in El Chal, Petén, Guatemala
- Author
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Betancourt, Herty, Pezo, D., and CATIE - Centro Agronómico Tropical de Investigación y Enseñanza
- Subjects
ANÁLISIS ECONÓMICO ,DEGRADACIÓN ,PASTIZALES ,GANADO ,PRODUCCIÓN ANIMAL ,RENDIMIENTO ,GUATEMALA ,Sede Central ,RAZAS MIXTAS - Abstract
Tesis (Mag.Sc.) - CATIE, Turrialba (Costa Rica), 2006 Se evaluó el impacto de la degradación de pasturas sobre la productividad animal y los ingresos de fincas ganaderas con sistemas de doble propósito en El Chal, Petén, Guatemala. Se cuantificó la disponibilidad de biomasa forrajera en pasturas representativas de cinco niveles de degradación (no degradación, leve, moderada, severa y muy severa), por medio del método de rendimiento comparativo (BOTANAL), luego de estratificar potreros con base en la estimación visual de cobertura de especies de pastos palatables. El ingreso neto promedio obtenido muestra que las fincas pagan los costos totales de Producción, pero no lo suficiente para capitalizarse, según lo mostrado por el valor esperado de la tierra. La productividad animal tendió a declinar linealmente a medida se incrementó el nivel de degradación de la pastura (Dx). Estos cambios resultan en una disminución del ingreso neto de hasta el 34 y 43 por ciento cuando se considera la Producción de leche y ganancia de peso en estadios muy severos de degradación de pasturas. The impact of pasture degradation on animal productivity and income in dual purpose cattle systeMON was assessed in El Chal, Petén, Guatemala. the biomass availability for pastures representing five levels of degradation (non-degraded, slight, moderate, severe and very severe degradation) was quantified by using the comparative yield method of (BOTANAL), applied after stratification of pastures based on visual estimates of palatable species coverage. The average net income obtained indicates that monitored farMON pay total costs of production, but income is not enough for farm capitalization, as indicated by the expected land value index. Animal productivity declined linearly as pasture degradation level (Dx) increased. Those changes results in a maximum decline in net income of 34 and 43 per cent, when milk yield and live-weight gain for the very severely degraded pastures are considered.
- Published
- 2006
32. Animal selectivity of woody and herbaceous forages in naturalized pastures as a function of seasons, management and landscape conditions in Muy Muy, Nicaragua
- Author
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Velásquez Vélez, Raúl A. and Pezo, D.
- Subjects
PLANTAS FORRAJERAS ,PLANTAS LEÑOSAS ,PREFERENCIAS ALIMENTARIAS ,FACTORES AMBIENTALES ,NICARAGUA ,PASTOREO ,ARBUSTOS ,PAISAJE ,GANADO ,FORRAJES ,ARBOLES ,COMPOSICIÓN BOTÁNICA ,SISTEMAS DE ALIMENTACIÓN - Abstract
Tesis (Mag.Sc.) - CATIE, Turrialba (Costa Rica), 2005 En pasturas con composición botánica muy diversa, como es el caso de las pasturas naturalizadas en Muy Muy (Nicaragua), el conocimiento de las especies que aparecen en la dieta del ganado comparadas con la composición de la pastura bajo diferentes condiciones y regímenes de pastoreo, ayuda a definir cuáles son las alternativas más favorables de manejo de pasturas. Por tal motivo se evaluó la selectividad animal por los forrajes a diferentes escalas jerárquicas (sitios de alimentación y especies individuales) en relación a dos tipos de paisaje (las planicies onduladas y las vegas de ríos), dos tipos de manejo (vacas lactantes y vacas secas), durante las épocas seca y húmeda. Con los resultados obtenidos se corrobora la hipótesis que los animales seleccionan su alimento a diferentes escalas espaciales. Además, la selectividad animal varía de acuerdo con la composición botánica de las pasturas en los diferentes tipos de paisaje, tratamientos y épocas. In pastures with very diverse botanical composition, as is the case of naturalized pastures in Muy Muy (Nicaragua), to know which species are eaten by cattle compared to all those present in the pastures managed under different grazing conditions, helps to define the most favourable pasture management alternatives. For that purpose, we evaluated forage selectivity by grazing animals at different hierarchical levels (grazing paths and individual species), under two landscape condition (undulating lands and riverbanks), and two animal management regimes, during the dry and wet seasons. The results obtained in this study confirm that grazing selectivity functions at different spatial levels. Also, selectivity is influenced by differences in botanical composition according to landscape types, treatments and seasons.
- Published
- 2005
33. Analysis of Bioactive Aroma Compounds in Essential Oils from Algerian Plants: Implications for Potential Antioxidant Applications.
- Author
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Bertella A, Gavril GL, Wrona M, Pezo D, Sidaoui A, Benlahcen K, Kihal M, Olewnik-Kruszkowska E, Salafranca J, and Nerín C
- Abstract
In samples of Artemisia campestris (AC), Artemisia herba-alba (AHA) and Salvia jordanii (SJ) essential oils, up to 200 distinct volatile compounds were identified. Using headspace solid-phase microextraction combined with gas chromatography-olfactometry-mass spectrometry (HS-SPME-GC-O-MS), different panelists detected 52 of these compounds. This study offers the most detailed analysis of bioactive compound profiles conducted so far. The most abundant compounds identified were curcumene, making up 12.96% of AC, and camphor, constituting 21.67% of AHA and 19.15% of SJ. The compounds with the highest odor activity value (OAV) were (E,Z) -2,4-nonadienal (geranium, pungent), 3-nonenal (cucumber) and 2-undecenal (sweet) in AC, AHA and SJ, respectively. AHA essential oil showed significant antioxidant activity (IC
50 = 41.73 ± 4.14 mg/g) and hydroxyl radical generation (hydroxylation percentage = 29.62 ± 3.14), as assessed by the diphenylpicrylhydrazyl (DPPH) method. In terms of oxygen radical absorbance capacity (ORAC), the strongest antioxidant activity was obtained for SJ essential oil (antioxidant activity of the essential oils, AOX = 337.49 ± 9.87).- Published
- 2024
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34. Parasitological status of vicuñas (Vicugna vicugna) from southeastern Peru and its relationship with fiber quality.
- Author
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Arias-Pacheco C, Pezo D, Mathias LA, Tebaldi JH, Castelo-Oviedo H, and Lux-Hoppe EG
- Subjects
- Animals, Animals, Domestic, Feces, Female, Male, Ovum, Peru epidemiology, Camelids, New World, Eimeria
- Abstract
We aim to describe the parasitic population in vicuñas from three Andean communities and its relationship with fiber quality using 115 fecal and 22 fiber samples, classified according to sex, age, body condition score, and management system. Coproparasitologic diagnostic revealed that 84.4% of animals presented at least one type of parasite egg/oocyst. Most frequent parasite egg/oocyst were Strongyle-type eggs (54.8%) and Eimeria punoensis (38.3%). Wild vicuñas had a higher prevalence of Strongyle-type eggs (91.4%) than semi-captive (38.8%) animals, and age was significative to Eimeria infection; crias had the highest frequency (100%) when compared to yearlings (84.2%) and adults (49.4%). Larvae identification revealed a strong influence of domestic animals on vicuña parasite community, presenting the first report of Bunostomum phlebotomum and Gaigeria pachyscelis in vicuñas from southeastern Peru. Females had a significantly finer diameter of fiber (13.05 ± 0.73 μm) than males (14.22 ± 1.22 μm), and infection with Eimeria spp. affected negatively fiber diameter and resistance. Our results provide data for disease surveillance and encourage further parasitological studies in vicuñas.
- Published
- 2021
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35. Genetic diversity and zoonotic potential of rotavirus A strains in the southern Andean highlands, Peru.
- Author
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Rojas M, Dias HG, Gonçalves JLS, Manchego A, Rosadio R, Pezo D, and Santos N
- Subjects
- Animals, Peru, Rotavirus Infections virology, Zoonoses virology, Genetic Variation, Rotavirus genetics, Rotavirus Infections transmission, Rotavirus Infections veterinary, Zoonoses transmission
- Abstract
Interspecies transmission is an important mechanism of evolution and contributes to rotavirus A (RVA) diversity. In order to evaluate the detection frequency, genetic diversity, epidemiological characteristics and zoonotic potential of RVA strains in faecal specimens from humans and animals cohabiting in the same environment in the department of Cusco, Peru, by molecular analysis, 265 faecal specimens were obtained from alpacas, llamas, sheep and shepherd children, and tested for RVA by RT-PCR. Genotyping was performed by multiplex PCR and sequence analysis. Rotavirus A was detected in 20.3% of alpaca, 47.5% of llama, 100% of sheep and 33.3% of human samples. The most common genetic constellations were G3-P[40]-I8-E3-H6 in alpacas, G1/G3-P[8]-I1-E1-H1 in llamas, G1/G3/G35-P[1]/P[8]-I1-E1-H1 in sheep and G3-P[40]-I1/I8-E3-H1 in humans. The newly described genotypes P[40] and P[50] were identified in all host species, including humans. Genotyping showed that the majority of samples presented coinfection with two or more RVA strains. These data demonstrate the great genetic diversity of RVA in animals and humans in Cusco, Peru. Phylogenetic analysis suggested that the strains represent zoonotic transmission among the species studied. Due to the characteristics of the human and animal populations in this study (cohabitation of different host species in conditions of poor sanitation and hygiene), the occurrence of zoonoses is a real possibility., (© 2019 Blackwell Verlag GmbH.)
- Published
- 2019
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36. Molecular epidemiology of coronavirus in faeces of Brazilian calves and Peruvian camelid herds.
- Author
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Rocha CB, Fornells LAAMG, Rojas M, Libetal M, Manchego A, Pezo D, and Santos N
- Abstract
Introduction: The enteric disorders represent a serious hazard for bovine and camelid breeding. The aim of this study was to examine the frequency of detection and molecular characteristics of enteric coronavirus (CoV) infections in cattle, alpaca, and llama herds bred in family-based farms in Brazil and Peru., Methodology: Stool samples were collected from calves from Brazil and camelids from Peru for detection and characterization of CoV by reverse transcription polymerase chain reaction (RT-PCR) and sequence analysis., Results: 46.5% (47/101) samples from calves and 26.8% (70/261) from alpaca tested positive for CoV. All strains belong to lineage A1 of the Betacoronavirus genus. Phylogenetic analysis showed high identity between CoV strains detected in calves and alpacas., Conclusions: This study characterised CoV strains from dairy cattle herds in the state of Rio de Janeiro, Brazil, and indicated that this virus is spread among the state herds. The results also indicate widespread circulation of CoV among the alpacas of Cuzco, Peru.
- Published
- 2018
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37. Identification and quantification of odours from oxobiodegradable polyethylene oxidised under a free radical flow by headspace solid-phase microextraction followed by gas chromatography-olfactometry-mass spectrometry.
- Author
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Wrona M, Vera P, Pezo D, and Nerín C
- Subjects
- Food Packaging, Free Radicals chemistry, Oxidation-Reduction, Gas Chromatography-Mass Spectrometry methods, Odorants analysis, Olfactometry methods, Polyethylene chemistry, Solid Phase Microextraction methods
- Abstract
Recently oxobiodegradable polyethylene gained popularity as food packaging material due to its potential to reduce polymer waste. However, this type of material can release after its oxidation off-odour compounds that affect the organoleptic properties of packaged food. Odour compounds released from both polyethylene and oxobiodegradable polyethylene before and after oxidation under a free radicals flow were investigated after 1 day, 2 days and 3 days of oxidation. The samples were analysed using headspace solid phase microextraction followed by gas chromatography-mass spectrometry and headspace solid phase microextraction coupled to gas chromatography-olfactometry-mass spectrometry. Sixty-two different odorous compounds were identified. 4-methylthio-2-butanone (fruit), nonanal (fat) and 3,6-nonadienal (fat) were present in different materials before oxidation. Multiple headspace-solid phase microextraction has been used to quantify all analytes. The most abundant compound was (Z)-3-hexenyl hexanoate with a concentration range between 1.5791±0.1387µg/g and 4.8181±0.3123µg/g. Compounds such as 2-dodecenal, 2-octenal, 2-pentanol, 3-nonenal, 3,6-nonadienal, ethyl 3-methylbutanoate, ethyl octenoate, hexanone, isopropyl hexanoate, octanal were below their LOD evaluated using MS detector; however, they were detected by gas chromatography-olfactometry. The minimum LOD and LOQ were 0.011µg/g and 0.036µg/g, respectively., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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38. Sero-prevalence of Taenia spp. cysticercosis in rural and urban smallholder pig production settings in Uganda.
- Author
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Kungu JM, Dione MM, Ejobi F, Harrison LJ, Poole EJ, Pezo D, and Grace D
- Subjects
- Animal Husbandry standards, Animals, Cross-Sectional Studies, Cysticercosis epidemiology, Cysticercosis prevention & control, Enzyme-Linked Immunosorbent Assay, Humans, Likelihood Functions, Prevalence, Rural Population, Sensitivity and Specificity, Seroepidemiologic Studies, Swine, Swine Diseases epidemiology, Uganda epidemiology, Cysticercosis veterinary, Red Meat parasitology, Sus scrofa parasitology, Swine Diseases parasitology, Taenia solium isolation & purification
- Abstract
The pork tapeworm, Taenia solium, is prevalent in Uganda although the prevalence has not been determined in all areas of the country. A cross-sectional study, to determine the sero-prevalence of the parasite in pigs kept under rural and urban production settings, was carried out in three Ugandan districts, Masaka, Mukono and Kamuli. Serum samples from 1185 pigs were tested for the presence of T. solium cysticercosis antigen using the HP10 antigen-ELISA (Ag-ELISA) and the ApDia Ag-ELISA assays. Using parallel interpretation of the two tests showed lower levels of observed prevalence of T. solium in rural production settings (10.8%) compared to urban (17.1%). Additionally, Maximum Likelihood Estimation for evaluating assays in the absence of a gold standard, using TAGS on the R platform, estimated the true sero-prevalence to be lower in rural production setting, 0.0% [0.0-3.2%; 95% confidence interval (CI)] than in urban production setting, 12.3% (4.2-77.5% CI). When the sensitivity/specificity (Se/Sp) of the assays were estimated, assuming conditional independence of the tests, HP10 Ag-ELISA was more sensitive and specific [(Se=53.9%; 10.1-100% CI), (Sp=97.0%; 95.9-100% CI)] than the ApDia assay [(Se=20.2%; 1.5-47.7% CI), (Sp=92.2%; 90.5-93.9% CI)]. Subject to parasitological verification, these results indicate there may be a need to implement appropriate control measures for T. solium in the study areas., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2017
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39. Qualitative analysis of the risks and practices associated with the spread of African swine fever within the smallholder pig value chains in Uganda.
- Author
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Dione M, Ouma E, Opio F, Kawuma B, and Pezo D
- Subjects
- African Swine Fever psychology, African Swine Fever virology, Animals, Risk Factors, Risk Reduction Behavior, Swine, Uganda, African Swine Fever transmission, Animal Husbandry methods, Farmers psychology, Health Knowledge, Attitudes, Practice
- Abstract
A study was undertaken between September 2014 and December 2014 to assess the perceptions of smallholder pig value chain actors of the risks and practices associated with the spread of African swine fever (ASF) disease within the pig value chains. Data was collected from 136 value chain actors and 36 key informants through 17 group discussions and two key informant interview (KII) sessions respectively using Participatory Rural Appraisal (PRA) tools. Results from this study revealed that according to value chain actors and stakeholders, the transporting, slaughtering, and collecting/bulking nodes represent the highest risk, followed by the inputs and services (feeds and drugs) supply nodes. The processing, whole sale and consumption nodes represented the lowest risk. Value chain actors are aware of the disease and its consequences to the pig industry, however biosecurity measures are poorly implemented at all nodes. As for the causes, value chain actors pointed to several factors, such as inadequate knowledge of mechanisms for the spread of the disease, poor enforcement of regulations on disease control, and low capacities of actors to implement biosecurity measures, amongst others. Although traders, butchers and veterinary practitioners accepted that they played an important role in the spread of the virus, they did not perceive themselves as key actors in the control of the disease; instead, they believed that only farmers should adopt biosecurity measures on their farms because they keep the pigs for a longer period. Most of the recommendations given by the value chain actors for controlling and preventing ASF disease were short term, and targeted mainly pig producers. These recommendations included: the establishment of live pig collection centres so that traders and brokers do not have to directly access pig farms, capacity building of value chain actors on application of biosecurity, enactment and enforcement of by-laws on live pig movements and establishment of operational outbreak reporting mechanism at district level. Long term recommendations included the development of a vaccine, as well as pen-side diagnostic tests. This study suggests that interventions to control ASF disease through application of biosecurity measures should target all value chain nodes, while putting more emphasis on post-farm nodes especially the trading., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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40. Whole-genome characterization of a Peruvian alpaca rotavirus isolate expressing a novel VP4 genotype.
- Author
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Rojas M, Gonçalves JL, Dias HG, Manchego A, Pezo D, and Santos N
- Subjects
- Animals, Diarrhea virology, Feces virology, Genotype, Horses, Humans, Peru, Phylogeny, Rotavirus isolation & purification, Rotavirus ultrastructure, Rotavirus Infections virology, Sequence Analysis, DNA veterinary, Camelids, New World virology, Capsid Proteins genetics, Diarrhea veterinary, Genome, Viral genetics, Rotavirus genetics, Rotavirus Infections veterinary
- Abstract
The SA44 isolate of Rotavirus A (RVA) was identified from a neonatal Peruvian alpaca presenting with diarrhea, and the full-length genome sequence of the isolate (designated RVA/Alpaca-tc/PER/SA44/2014/G3P[40]) was determined. Phylogenetic analyses showed that the isolate possessed the genotype constellation G3-P[40]-I8-R3-C3-M3-A9-N3-T3-E3-H6, which differs considerably from those of RVA strains isolated from other species of the order Artiodactyla. Overall, the genetic constellation of the SA44 strain was quite similar to those of RVA strains isolated from a bat in Asia (MSLH14 and MYAS33). Nonetheless, phylogenetic analyses of each genome segment identified a distinct combination of genes. Several sequences were closely related to corresponding gene sequences in RVA strains from other species, including human (VP1, VP2, NSP1, and NSP2), simian (VP3 and NSP5), bat (VP6 and NSP4), and equine (NSP3). The VP7 gene sequence was closely related to RVA strains from a Peruvian alpaca (K'ayra/3368-10; 99.0% nucleotide and 99.7% amino acid identity) and from humans (RCH272; 95% nucleotide and 99.0% amino acid identity). The nucleotide sequence of the VP4 gene was distantly related to other VP4 sequences and was designated as the reference strain for the new P[40] genotype. This unique genetic makeup suggests that the SA44 strain emerged from multiple reassortment events between bat-, equine-, and human-like RVA strains., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
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41. Serological and molecular investigation for brucellosis in swine in selected districts of Uganda.
- Author
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Erume J, Roesel K, Dione MM, Ejobi F, Mboowa G, Kungu JM, Akol J, Pezo D, El-Adawy H, Melzer F, Elschner M, Neubauer H, and Grace D
- Subjects
- Animals, Antibodies, Bacterial blood, Brucella suis genetics, Brucella suis immunology, Brucellosis epidemiology, Cross-Sectional Studies, Enzyme-Linked Immunosorbent Assay veterinary, Real-Time Polymerase Chain Reaction veterinary, Red Meat standards, Seroepidemiologic Studies, Swine, Swine Diseases blood, Uganda epidemiology, Brucella suis isolation & purification, Brucellosis veterinary, Swine Diseases epidemiology
- Abstract
Brucellosis is a notifiable zoonotic disease affecting livestock, humans, and wildlife in Uganda. Pigs can be infected with human pathogenic Brucella suis biovars 1 and 3 and can be a significant source of brucellosis for humans. Uganda has a rapidly growing pig population, and the pork consumption per capita is the highest in East Africa. The objective of this work was to determine the seroprevalence of brucellosis in Ugandan pigs. A cross-sectional serosurvey of pigs was conducted in three of the major pig-keeping districts in Uganda (Masaka (n = 381 samples), Mukono (n = 398), and Kamuli (n = 414)). In addition, pigs originating from these districts were sampled in the major pig abattoir in Kampala (n = 472). In total, 1665 serum samples were investigated by serological and molecular tests. Only three putative brucellosis-positive samples were detected serologically using indirect ELISA. These sera were found negative for Brucella antibodies by CFT; however, two had antibodies against Yersinia enterocolitica as determined by SAT. Presence of antibodies against Yersiniae was confirmed by Y. enterocolitica antibody-specific ELISA. The two Yersiniae ELISA-positive samples were brucellosis negative using real-time PCR. We tested additional 142 sera from the 1665 samples with real-time PCR. All tested negative. Under this type of production system, we expect a maximum B. suis prevalence of less than 1 % at 95 % confidence level, and therefore, the risk of acquiring brucellosis from the pigs or their products is negligible. However, pigs may harbor the zoonotic Y. enterocolitica. This is the first study to investigate the occurrence of brucellosis in pigs in Uganda and the first study to report Y. enterocolitica antibodies in swine in Uganda.
- Published
- 2016
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42. Outbreak of diarrhea among preweaning alpacas (Vicugna pacos) in the southern Peruvian highland.
- Author
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Rojas M, Manchego A, Rocha CB, Fornells LA, Silva RC, Mendes GS, Dias HG, Sandoval N, Pezo D, and Santos N
- Subjects
- Animals, Diarrhea epidemiology, Diarrhea etiology, Peru epidemiology, Bacteria isolation & purification, Camelids, New World, Diarrhea veterinary, Disease Outbreaks, Parasites isolation & purification, Viruses isolation & purification
- Abstract
Introduction: Infections, particularly diarrheal infections, are a major cause of neonatal death in South American camelids. The aim of this study was to identify the pathogens that could have caused the recent diarrhea outbreak among the alpacas in Silli, Cusco, located in the southern Peruvian highland., Methodology: Spleen, kidney, and intestine tissue along with fecal and intestinal lavage samples were obtained from 50 one- to five-week-old alpacas and analyzed for the presence of parasites, bacteria, and viruses., Results: Laboratory testing of the 50 crias included in this study revealed that 80% were infected with Eimeria spp., 40% with coronavirus, 34% with E. coli, 32% with rotavirus, 22% with Clostridium spp., and 20% with Cryptosporidium spp. Of these 50 alpaca crias, 20 presented with a single infection (19 positive for Eimeria spp. and 1 positive for rotavirus). Co-infections with up to four pathogens occurred in 60% of the samples. The significance of such infections is not clear, but it is noteworthy that the animals suffering from necrotic and/or hemorrhagic enteritis presented with quadruple infections. It is likely that co-infections increase the severity of the disease., Conclusions: These data show that multiple pathogens circulate among young alpaca crias and could be associated with diarrheal disease in these animals. The findings from this study warrant the provision of subsidies for future assessment of the potential economic impact of these infections on the productivity of the Peruvian alpaca industry.
- Published
- 2016
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43. Ultra high performance liquid chromatography coupled to quadruple time-of-flight with MS(E) technology used for qualitative analysis of non-volatile oxidation markers in sliced packed mushrooms (Agaricus Bisporus).
- Author
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Wrona M, Pezo D, Canellas E, and Nerín C
- Subjects
- Animals, Biomarkers analysis, Chromatography, High Pressure Liquid methods, Food Packaging, Mass Spectrometry methods, Oxidation-Reduction, Spain, Agaricus chemistry
- Abstract
61 different non-volatile compounds were determined in Agaricus Bisporus sliced mushrooms using UHPLC/Q-TOF with MS(E) technology. Both positive and negative electrospray ionization were applied. Chemical profile of three parts of mushroom was created: cap, gills and stipe. The analysed mushrooms were oxidized to identify the non-volatile markers in their parts. MarkerLynx(®) was proposed as a powerful tool to distinguish mushrooms purchased in different countries (Spain and Portugal) by determining their non-volatile markers. Some metabolites were identified. Surprisingly a mix of polyethylene glycols (PEGs) was detected in cap and gills of mushrooms. Whole mushrooms were considered as vegetable resistant to migration from packaging compounds. Additionally migration tests were performed to determine the source of migrating compounds., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
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44. Participatory assessment of animal health and husbandry practices in smallholder pig production systems in three high poverty districts in Uganda.
- Author
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Dione MM, Ouma EA, Roesel K, Kungu J, Lule P, and Pezo D
- Subjects
- Animals, Humans, Surveys and Questionnaires, Uganda, Animal Husbandry methods, Health Knowledge, Attitudes, Practice, Sus scrofa physiology
- Abstract
While animal health constraints have been identified as a major limiting factor in smallholder pig production in Uganda, researchers and policy makers lack information on the relative incidence of diseases and their impacts on pig production. This study aimed to assess animal health and management practices, constraints and opportunities for intervention in smallholder pig value chains in three high poverty districts of Uganda. Semi-qualitative interview checklists through Focus Group Discussions (FGDs) were administered to 340 pig farmers in 35 villages in Masaka, Kamuli and Mukono districts. Quantitative data was obtained during the exercise through group consensus. Results of FGDs were further triangulated with secondary data and information obtained from key informant interviews. Findings show that pig keeping systems are dominated by tethering and scavenging in rural areas. In peri-urban and urban areas, intensive production systems are more practiced, with pigs confined in pens. The main constraints identified by farmers include high disease burden such as African swine fever (ASF) and parasites, poor housing and feeding practices, poor veterinary services, ineffective drugs and a general lack of knowledge on piggery management. According to farmers, ASF is the primary cause of pig mortality with epidemics occurring mainly during the dry season. Worms and ectoparasites namely; mange, lice and flies are endemic leading to stunted growth which reduces the market value of pigs. Diarrhoea and malnutrition are common in piglets. Ninety-three percent of farmers say they practice deworming, 37% practice ectoparasite spraying and 77% castrate their boars. Indigenous curative treatments include the application of human urine and concoctions of local herbs for ASF control and use of old engine oil or tobacco extracts to control ectoparasites. There is a need for better technical services to assist farmers with these problems., (Copyright © 2014 Elsevier B.V. All rights reserved.)
- Published
- 2014
- Full Text
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45. Diffusion approximation-based simulation of stochastic ion channels: which method to use?
- Author
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Pezo D, Soudry D, and Orio P
- Abstract
To study the effects of stochastic ion channel fluctuations on neural dynamics, several numerical implementation methods have been proposed. Gillespie's method for Markov Chains (MC) simulation is highly accurate, yet it becomes computationally intensive in the regime of a high number of channels. Many recent works aim to speed simulation time using the Langevin-based Diffusion Approximation (DA). Under this common theoretical approach, each implementation differs in how it handles various numerical difficulties-such as bounding of state variables to [0,1]. Here we review and test a set of the most recently published DA implementations (Goldwyn et al., 2011; Linaro et al., 2011; Dangerfield et al., 2012; Orio and Soudry, 2012; Schmandt and Galán, 2012; Güler, 2013; Huang et al., 2013a), comparing all of them in a set of numerical simulations that assess numerical accuracy and computational efficiency on three different models: (1) the original Hodgkin and Huxley model, (2) a model with faster sodium channels, and (3) a multi-compartmental model inspired in granular cells. We conclude that for a low number of channels (usually below 1000 per simulated compartment) one should use MC-which is the fastest and most accurate method. For a high number of channels, we recommend using the method by Orio and Soudry (2012), possibly combined with the method by Schmandt and Galán (2012) for increased speed and slightly reduced accuracy. Consequently, MC modeling may be the best method for detailed multicompartment neuron models-in which a model neuron with many thousands of channels is segmented into many compartments with a few hundred channels.
- Published
- 2014
- Full Text
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46. Rapid analytical procedure for determination of mineral oils in edible oil by GC-FID.
- Author
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Wrona M, Pezo D, and Nerin C
- Subjects
- Chromatography, Gas instrumentation, Discriminant Analysis, Limit of Detection, Olive Oil, Chromatography, Gas methods, Food Contamination analysis, Mineral Oil analysis, Plant Oils chemistry
- Abstract
A procedure for the determination of mineral oils in edible oil has been fully developed. The procedure consists of using a sulphuric acid-impregnated silica gel (SAISG) glass column to eliminate the fat matter. A chemical combustion of the fatty acids takes place, while the mineral oils are not affected by the sulphuric acid. The column is eluted with hexane using a vacuum pump and the final extract is concentrated and analysed by gas chromatography (GC) with flame ionisation detector (FID). The detection limit (LOD) and the quantification limit (LOQ) in hexane were 0.07 and 0.21 μg g(-1) respectively and the LOQ in vegetable oil was 1 μg g(-1). Only a few minutes were necessary for sample treatment to have a clean extract. The efficiency of the process, measured through the recoveries from spiked samples of edible oil was higher than 95%. The procedure has been applied to determine mineral oil in olive oil from the retailed market., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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47. Mathematical analysis and modeling of motion direction selectivity in the retina.
- Author
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Escobar MJ, Pezo D, and Orio P
- Subjects
- Amacrine Cells physiology, Animals, Humans, Neural Inhibition physiology, Retinal Ganglion Cells physiology, Visual Pathways cytology, Visual Pathways physiology, Models, Theoretical, Motion Perception physiology, Retina cytology, Retina physiology
- Abstract
Motion detection is one of the most important and primitive computations performed by our visual system. Specifically in the retina, ganglion cells producing motion direction-selective responses have been addressed by different disciplines, such as mathematics, neurophysiology and computational modeling, since the beginnings of vision science. Although a number of studies have analyzed theoretical and mathematical considerations for such responses, a clear picture of the underlying cellular mechanisms is only recently emerging. In general, motion direction selectivity is based on a non-linear asymmetric computation inside a receptive field differentiating cell responses between preferred and null direction stimuli. To what extent can biological findings match these considerations? In this review, we outline theoretical and mathematical studies of motion direction selectivity, aiming to map the properties of the models onto the neural circuitry and synaptic connectivity found in the retina. Additionally, we review several compartmental models that have tried to fill this gap. Finally, we discuss the remaining challenges that computational models will have to tackle in order to fully understand the retinal motion direction-selective circuitry., (Copyright © 2013 Elsevier Ltd. All rights reserved.)
- Published
- 2013
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48. Aromatic amines from polyurethane adhesives in food packaging: the challenge of identification and pattern recognition using Quadrupole-Time of Flight-Mass SpectrometryE.
- Author
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Pezo D, Fedeli M, Bosetti O, and Nerín C
- Subjects
- Amines chemistry, Food Packaging, Adhesives chemistry, Amines analysis, Food Contamination, Polyurethanes chemistry, Tandem Mass Spectrometry
- Abstract
Toxic primary aromatic amines (PAAs) are reaction products from residual isocyanates in polyurethane adhesives. The maximum migration level of the total sum of PAAs is 10 ng g(-1) of food. This paper reports on a method for quantification of 18 PAAs by UHPLC-MS/MS that was optimised and applied to a series of industrial laminates prepared from polyurethane adhesives. Non-intentionally added substances (NIAS), impurities and other migrants were identified by Q-TOF/MS(E). A comparison of the quantitative values obtained by the colorimetric method using NEDA and by UHPLC-MS/MS confirmed that the first method can overestimate the quantification of PAAs. This could be attributed to the impurities and other NIAS present in the plastic laminate. Values of R(2) in the analytical characteristics of UHPLC-MS/MS were obtained, the best value being 0.9964 and the most unfavourable 0.7626. The detection limit (LOD) and the quantification limit (LOQ) were 2 pg g(-1) and 7 pg g(-1), respectively. The stability of the PAAs over time in the acidic simulant in contact with the plastic laminate is also reported., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
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49. Analytical procedure for the determination of Ethyl Lauroyl Arginate (LAE) to assess the kinetics and specific migration from a new antimicrobial active food packaging.
- Author
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Pezo D, Navascués B, Salafranca J, and Nerín C
- Subjects
- Arginine analysis, Chromatography, High Pressure Liquid methods, Cobalt analysis, Kinetics, Limit of Detection, Reproducibility of Results, Solutions, Spectrophotometry, Ultraviolet, Thiocyanates analysis, Water chemistry, Anti-Bacterial Agents analysis, Arginine analogs & derivatives, Cobalt chemistry, Food Packaging, Liquid-Liquid Extraction methods, Thiocyanates chemistry
- Abstract
Ethyl Lauroyl Arginate (LAE) is a cationic tensoactive compound, soluble in water, with a wide activity spectrum against moulds and bacteria. LAE has been incorporated as antimicrobial agent into packaging materials for food contact and these materials require to comply with the specific migration criteria. In this paper, one analytical procedure has been developed and optimized for the analysis of LAE in food simulants after the migrations tests. It consists of the formation of an ionic pair between LAE and the inorganic complex Co(SCN)(4)(2-) in aqueous solution, followed by a liquid-liquid extraction in a suitable organic solvent and further UV-Vis absorbance measurement. In order to evaluate possible interferences, the ionic pair has been also analyzed by high performance liquid chromatography with UV-Vis detection. Both procedures provided similar analytical characteristics, with linear ranges from 1.10 to 25.00 mg kg(-1), linearity higher than 0.9886, limits of detection and quantification of 0.33 and 1.10 mg kg(-1), respectively, accuracy better than 1% as relative error and precision better than 3.6% expressed as RSD. Optimization of analytical techniques, thermal and chemical stability of LAE, as well as migration kinetics of LAE from experimental active packaging are reported and discussed., (Copyright © 2012 Elsevier B.V. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
50. [Swelling of right knee in an immunologically compromised patient].
- Author
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Cajigas-Pezo D, Lorenzo-Hernandez A, Vives-Rivero GR, and Rentero-Martínez Z
- Subjects
- AIDS-Related Opportunistic Infections diagnosis, AIDS-Related Opportunistic Infections diagnostic imaging, AIDS-Related Opportunistic Infections drug therapy, Adult, Antitubercular Agents therapeutic use, Arthritis, Infectious diagnosis, Arthritis, Infectious diagnostic imaging, Arthritis, Infectious drug therapy, Bacteremia microbiology, Candidiasis, Oral complications, Clarithromycin therapeutic use, Drug Therapy, Combination, Ethambutol therapeutic use, Humans, Immunocompromised Host, Isoniazid therapeutic use, Knee Joint diagnostic imaging, Male, Mycobacterium Infections, Nontuberculous diagnosis, Mycobacterium Infections, Nontuberculous diagnostic imaging, Mycobacterium Infections, Nontuberculous drug therapy, Radiography, Rifampin therapeutic use, Tuberculosis, Osteoarticular diagnosis, Tuberculosis, Osteoarticular diagnostic imaging, Tuberculosis, Osteoarticular drug therapy, AIDS-Related Opportunistic Infections microbiology, Arthritis, Infectious microbiology, Knee Joint microbiology, Mycobacterium Infections, Nontuberculous microbiology, Mycobacterium kansasii isolation & purification, Tuberculosis, Osteoarticular microbiology
- Published
- 2012
- Full Text
- View/download PDF
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