Wilfredo Molina | University of Houston-Downtown (original) (raw)

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Papers by Wilfredo Molina

Acta Oecologica-international Journal of Ecology, 2008

Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numer... more Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numerous studies have shown that plant tolerance is affected by nutrient availability, but the effect of soil moisture has received less attention. We evaluated tolerance of apical damage (clipping that mimicked insect damage) under two watering regimes (control watering and drought) in the tarweed Madia sativa (Asteraceae). We recorded number of heads with seeds and total number of heads as traits related to fitness. Net photosynthetic rate, water use efficiency, number of branches, shoot biomass, and the root:shoot biomass ratio were measured as traits potentially related to tolerance via compensatory responses to damage. In the drought treatment, damaged plants showed ≈43% reduction in reproductive fitness components in comparison with undamaged plants. In contrast, there was no significant difference in reproductive fitness between undamaged and damaged plants in the control watering treatment. Shoot biomass was not affected by apical damage. The number of branches increased after damage in both water treatments but this increase was limited by drought stress. Net photosynthetic rate increased in damaged plants only in the control watering treatment. Water use efficiency increased with drought stress and, in plants regularly watered, also increased after damage. Root:shoot ratio was higher in the low water treatment and damaged plants tended to reduce root:shoot ratio only in this water treatment. It is concluded that water availability limits tolerance to apical damage in M. sativa, and that putative compensatory mechanisms are differentially affected by water availability.

Veterinary Parasitology, 2005

Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were u... more Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were used to establish an immunoblot, an ELISA and an IFAT to detect antibodies against N. caninum tachyzoites. Subsequently, serum samples collected from a total of 871 South American Camelids (SAC: Lama glama, Lama pacos, Lama vicugna) of two farms in Peru and from 32 SAC of a farm in central Germany were examined for antibodies against N. caninum and Toxoplasma gondii. Based on the recognition of specific bands in the immunoblot, sera of SAC from Peru were differentiated into N. caninum-positive (n = 18) and T. gondii-positive (n = 30) samples and into samples negative or inconclusive for both parasites. Using the immunoblot results as the reference, a modified version of the p38-ELISA and the IFAT were evaluated for detecting N. caninum antibodies in SAC sera. Applying a cut-off as determined by two graph-receiver operating characteristic analysis both, the ELISA and the IFAT, exhibited a sensitivity and specificity of about 95% in the SAC sera from Peru. Serological testing confirmed that SAC may become infected with N. caninum under field conditions in Peru. In addition to alpacas and llamas also 114 wild living vicuñas had been examined for antibodies against N. caninum. However, only the alpacas and llamas but no vicuñas were found N. caninum-positive. In contrast, T. gondii-seropositive animals were detected in all three SAC species. The lack of N. caninumseropositive vicuñas indicates that in the study area in Peru wild canids might not serve as definitive hosts of N. caninum while www.elsevier.com/locate/vetpar Veterinary Parasitology 130 for T. gondii a life cycle including wild felids is likely. On the German farm no N. caninum-but only T. gondii-seropositive SAC (n = 14) were detected. The seroprevalence of T. gondii infection was significantly higher in adult SAC (alpacas in Peru, llamas in Germany) than in crias (i.e. <12 months old foals) indicating that the predominant route of infection is post natal. Since the present study was restricted to a few farms, the seroprevalences determined are not representative. However, our results confirm natural infections with N. caninum and T. gondii in SAC. Whether these infections are linked to any disease, e.g. reproductive losses, has to be clarified in further studies. #

RESUMEN: Se realizó un estudio descriptivo en la consulta de planificación familiar de Santos Suá... more RESUMEN: Se realizó un estudio descriptivo en la consulta de planificación familiar de Santos Suárez en el período de 1 año a partir de abril de 1998. La muestra la conformó el total de mujeres mayores de 35 años que acudieron por primera vez a la consulta de planificación familiar, a las que se les llenó un cuestionario. Los datos se procesaron con el cálculo porcentual. Se concluyó que la asistencia de las mujeres mayores de 35 años a la consulta de planificación familiar fue baja; predominaron las que tienen unión estable (82,6 %), nivel de escolaridad preuniversitario (60,9 %) y trabajadoras (69,6 %); la presencia de otros factores de riesgo reproductivo preconcepcional diferentes a la edad fue baja (39,12 %) y la mayoría seleccionó los dispositivos intrauterinos y los anticonceptivos hormonales inyectables sólo de progestina.

Acta Oecologica-international Journal of Ecology, 2008

Branching Herbivory Photosynthesis Plant tolerance Root:shoot ratio a b s t r a c t Plant toleran... more Branching Herbivory Photosynthesis Plant tolerance Root:shoot ratio a b s t r a c t Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness.

Con el objetivo de obtener sales de citrato de calcio y magnesio como ingrediente alimentario a p... more Con el objetivo de obtener sales de citrato de calcio y magnesio como ingrediente alimentario a partir de conchas de choro, se procedió a disolver los minerales mediante lixiviación ácida en ebullición. Los rendimientos de lixiviación analizados en un diseño completamente al azar con arreglo factorial: 3 x 3 (a = 0,05%) (concha de choro molido: 3, 4 y 5% y ácido clorhídrico: 3, 5 y 7 %), señalaron como mayor rendimiento al conseguido con 4% (conchas de choro molido) y 7% (ácido clorhídrico) con 95,94% (p/p) de elementos en disolución, principalmente: Ca, Mg, Cu, Zn, Mn, Fe, K, Na y P y Si, Pb y As, en la fracción no disuelta de 4,06%. La adición de ácido cítrico al 60% (p/v) e hidróxido de potasio al 60% (p/v) en ebullición permitió precipitar de esta disolución las sales blancas de Ca y Mg, las que fueron sometidas a lavado, secado y molienda en molino de martillos. El néctar de durazno elaborado contiene 1,71% de sales de citrato, cumplió con las recomendaciones físicoquímicas y microbiológicas y mostró alta aceptabilidad sensorial y biodisponibilidad in vitro de 27,65 y 27,63% para el Ca y Mg, respectivamente.

Acta Oecologica-international Journal of Ecology, 2008

Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numer... more Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness. Numerous studies have shown that plant tolerance is affected by nutrient availability, but the effect of soil moisture has received less attention. We evaluated tolerance of apical damage (clipping that mimicked insect damage) under two watering regimes (control watering and drought) in the tarweed Madia sativa (Asteraceae). We recorded number of heads with seeds and total number of heads as traits related to fitness. Net photosynthetic rate, water use efficiency, number of branches, shoot biomass, and the root:shoot biomass ratio were measured as traits potentially related to tolerance via compensatory responses to damage. In the drought treatment, damaged plants showed ≈43% reduction in reproductive fitness components in comparison with undamaged plants. In contrast, there was no significant difference in reproductive fitness between undamaged and damaged plants in the control watering treatment. Shoot biomass was not affected by apical damage. The number of branches increased after damage in both water treatments but this increase was limited by drought stress. Net photosynthetic rate increased in damaged plants only in the control watering treatment. Water use efficiency increased with drought stress and, in plants regularly watered, also increased after damage. Root:shoot ratio was higher in the low water treatment and damaged plants tended to reduce root:shoot ratio only in this water treatment. It is concluded that water availability limits tolerance to apical damage in M. sativa, and that putative compensatory mechanisms are differentially affected by water availability.

Veterinary Parasitology, 2005

Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were u... more Sera of an experimentally Neospora caninum infected llama and a non-infected control llama were used to establish an immunoblot, an ELISA and an IFAT to detect antibodies against N. caninum tachyzoites. Subsequently, serum samples collected from a total of 871 South American Camelids (SAC: Lama glama, Lama pacos, Lama vicugna) of two farms in Peru and from 32 SAC of a farm in central Germany were examined for antibodies against N. caninum and Toxoplasma gondii. Based on the recognition of specific bands in the immunoblot, sera of SAC from Peru were differentiated into N. caninum-positive (n = 18) and T. gondii-positive (n = 30) samples and into samples negative or inconclusive for both parasites. Using the immunoblot results as the reference, a modified version of the p38-ELISA and the IFAT were evaluated for detecting N. caninum antibodies in SAC sera. Applying a cut-off as determined by two graph-receiver operating characteristic analysis both, the ELISA and the IFAT, exhibited a sensitivity and specificity of about 95% in the SAC sera from Peru. Serological testing confirmed that SAC may become infected with N. caninum under field conditions in Peru. In addition to alpacas and llamas also 114 wild living vicuñas had been examined for antibodies against N. caninum. However, only the alpacas and llamas but no vicuñas were found N. caninum-positive. In contrast, T. gondii-seropositive animals were detected in all three SAC species. The lack of N. caninumseropositive vicuñas indicates that in the study area in Peru wild canids might not serve as definitive hosts of N. caninum while www.elsevier.com/locate/vetpar Veterinary Parasitology 130 for T. gondii a life cycle including wild felids is likely. On the German farm no N. caninum-but only T. gondii-seropositive SAC (n = 14) were detected. The seroprevalence of T. gondii infection was significantly higher in adult SAC (alpacas in Peru, llamas in Germany) than in crias (i.e. <12 months old foals) indicating that the predominant route of infection is post natal. Since the present study was restricted to a few farms, the seroprevalences determined are not representative. However, our results confirm natural infections with N. caninum and T. gondii in SAC. Whether these infections are linked to any disease, e.g. reproductive losses, has to be clarified in further studies. #

RESUMEN: Se realizó un estudio descriptivo en la consulta de planificación familiar de Santos Suá... more RESUMEN: Se realizó un estudio descriptivo en la consulta de planificación familiar de Santos Suárez en el período de 1 año a partir de abril de 1998. La muestra la conformó el total de mujeres mayores de 35 años que acudieron por primera vez a la consulta de planificación familiar, a las que se les llenó un cuestionario. Los datos se procesaron con el cálculo porcentual. Se concluyó que la asistencia de las mujeres mayores de 35 años a la consulta de planificación familiar fue baja; predominaron las que tienen unión estable (82,6 %), nivel de escolaridad preuniversitario (60,9 %) y trabajadoras (69,6 %); la presencia de otros factores de riesgo reproductivo preconcepcional diferentes a la edad fue baja (39,12 %) y la mayoría seleccionó los dispositivos intrauterinos y los anticonceptivos hormonales inyectables sólo de progestina.

Acta Oecologica-international Journal of Ecology, 2008

Branching Herbivory Photosynthesis Plant tolerance Root:shoot ratio a b s t r a c t Plant toleran... more Branching Herbivory Photosynthesis Plant tolerance Root:shoot ratio a b s t r a c t Plant tolerance is the ability to reduce the negative impact of herbivory on plant fitness.

Con el objetivo de obtener sales de citrato de calcio y magnesio como ingrediente alimentario a p... more Con el objetivo de obtener sales de citrato de calcio y magnesio como ingrediente alimentario a partir de conchas de choro, se procedió a disolver los minerales mediante lixiviación ácida en ebullición. Los rendimientos de lixiviación analizados en un diseño completamente al azar con arreglo factorial: 3 x 3 (a = 0,05%) (concha de choro molido: 3, 4 y 5% y ácido clorhídrico: 3, 5 y 7 %), señalaron como mayor rendimiento al conseguido con 4% (conchas de choro molido) y 7% (ácido clorhídrico) con 95,94% (p/p) de elementos en disolución, principalmente: Ca, Mg, Cu, Zn, Mn, Fe, K, Na y P y Si, Pb y As, en la fracción no disuelta de 4,06%. La adición de ácido cítrico al 60% (p/v) e hidróxido de potasio al 60% (p/v) en ebullición permitió precipitar de esta disolución las sales blancas de Ca y Mg, las que fueron sometidas a lavado, secado y molienda en molino de martillos. El néctar de durazno elaborado contiene 1,71% de sales de citrato, cumplió con las recomendaciones físicoquímicas y microbiológicas y mostró alta aceptabilidad sensorial y biodisponibilidad in vitro de 27,65 y 27,63% para el Ca y Mg, respectivamente.