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Search Results: 1 - 10 of 24670 matches for " FERNANDO PUEBLA-OLIVARES "
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Diversidad de aves en bosques de pino-encino del centro de Guerrero, México
ALMAZáN-Nú?EZ, R. Carlos;PUEBLA-OLIVARES, Fernando;ALMAZáN-JUáREZ, ángel;
Acta zoológica mexicana , 2009,
Abstract: we assessed bird species richness and their abundances at three sites with pine-oak forest under different development stages (mature forest, regenerating forest and shade coffee plantation) in central guerrero, mexico. we recorded a total of 117 species and 1,276 individuals; however, analysis of cumulative species curves indicates that it is possible to find more species in the region for a more complete list. there were significant differences in species diversity among the three sites. species diversity was higher at the regenerating forest, middle in mature forest and lowest at shade coffee plantation. higher similarity was between mature forest and regenerating forest. there were no significant differences among the feeding guilds at any site. the mid-stratum had the highest utilization at the three sites. in addition, there were significant differences among strata in regenerating forest in comparison with mature forest and shade coffee plantation.
Genetic structure of a bird-dispersed tropical tree (Dendropanax arboreus) in a fragmented landscape in Mexico
Figueroa-Esquivel, Elsa M.;Puebla-Olivares, Fernando;Eguiarte, Luis E.;Nú?ez-Farfán, Juan;
Revista mexicana de biodiversidad , 2010,
Abstract: we analyzed the genetic structure of the tropical tree dendropanax arboreus (araliaceae) in relation to habitat fragmentation. genetic variation, structure, and genetic differentiation among populations from los tuxtlas tropical rainforest were estimated using issrs as molecular markers. dna from 219 individuals belonging to 9 populations was amplified with 4 primers yielding a total of 75 loci. adults and juveniles from each population were analyzed to assess the genetic diversity and structure pre and post-fragmentation, respectively. dendropanax arboreus showed high levels of genetic diversity (h = 0.253) and significant but low genetic differentiation among populations (= 0.062). a hierarchical analysis of the gvenetic structure showed that 91.5% of the genetic variation is attributable to individual differences within populations. the average nei's genetic distance among populations was low (d = 0.034) and genetic distance among pairs of populations increased with geographic distance separating them. because genetic diversity is similar between adult and juvenile trees at all but 2 populations, we suggest that seed dispersal prevented genetic differentiation and maintains genetic connectivity among fragments and continuous forest populations. juvenile populations showed a higher genetic differentiation (= 0.15) than adult trees, indicating a role of genetic drift via reduced population size.
Diversidad de aves en bosques de pino-encino del centro de Guerrero, México
R. Carlos ALMAZáN-Nú?EZ,Fernando PUEBLA-OLIVARES,ángel ALMAZáN-JUáREZ
Acta zoológica mexicana , 2009,
Abstract: Se estimó la riqueza y abundancia de aves en tres sitios con bosque de pino-encino con diferentes condiciones de desarrollo (bosque maduro, bosque en regeneración y bosque con cafetal) en el centro del estado de Guerrero, México. Entre los tres sitios se registró un total de 117 especies y 1,276 individuos; sin embargo, análisis de curvas de acumulación muestran que es posible registrar más especies para complementar el listado. Se obtuvieron diferencias significativas en la diversidad de especies entre los tres sitios, la mayor diversidad se presentó en el bosque en regeneración, seguido del bosque maduro y por último el bosque con cafetal. La mayor similitud de especies se registró entre el bosque maduro y el bosque en regeneración. No existen diferencias significativas entre los gremios alimentarios de los tres sitios. El estrato medio del bosque fue el más utilizado por las aves en los tres sitios, existiendo diferencias significativas en el uso de los estratos de la vegetación por las aves del bosque en regeneración en comparación con el bosque maduro, así como con el bosque con cafetal.
Genetic structure of a bird-dispersed tropical tree (Dendropanax arboreus) in a fragmented landscape in Mexico Estructura genética de un árbol tropical dispersado por aves (Dendropanax arboreus) en un paisaje fragmentado en México
Elsa M. Figueroa-Esquivel,Fernando Puebla-Olivares,Luis E. Eguiarte,Juan Nú?ez-Farfán
Revista mexicana de biodiversidad , 2010,
Abstract: We analyzed the genetic structure of the tropical tree Dendropanax arboreus (Araliaceae) in relation to habitat fragmentation. Genetic variation, structure, and genetic differentiation among populations from Los Tuxtlas tropical rainforest were estimated using ISSRs as molecular markers. DNA from 219 individuals belonging to 9 populations was amplified with 4 primers yielding a total of 75 loci. Adults and juveniles from each population were analyzed to assess the genetic diversity and structure pre and post-fragmentation, respectively. Dendropanax arboreus showed high levels of genetic diversity (h = 0.253) and significant but low genetic differentiation among populations ( or = 0.062). A hierarchical analysis of the gvenetic structure showed that 91.5% of the genetic variation is attributable to individual differences within populations. The average Nei's genetic distance among populations was low (D = 0.034) and genetic distance among pairs of populations increased with geographic distance separating them. Because genetic diversity is similar between adult and juvenile trees at all but 2 populations, we suggest that seed dispersal prevented genetic differentiation and maintains genetic connectivity among fragments and continuous forest populations. Juvenile populations showed a higher genetic differentiation ( or = 0.15) than adult trees, indicating a role of genetic drift via reduced population size. Se analizó la estructura genética del árbol tropical Dendropanax arboreus (Araliaceae) en relación con la fragmentación del hábitat en la selva tropical de Los Tuxtlas, Veracruz, México. La variación, estructura y diferenciación genética entre poblaciones del bosque continuo y de fragmentos se estimó usando ISSR como marcador molecular. El ADN de 219 individuos de 9 poblaciones se amplificó para 4 primers (75 loci). Se analizaron las poblaciones de árboles adultos y juveniles en cada sitio, representando la diversidad y estructura genética pre y postfragmentación, respectivamente. Dendropanax arboreus mostró altos niveles de variación genética (h = 0.253) y un nivel bajo de diferenciación entre poblaciones (= 0.062). Un análisis jerárquico de la estructura genética mostró que el 91.5% de la variación genética es atribuible a diferencias individuales dentro de las poblaciones. El promedio de las distancias genéticas de Nei entre las poblaciones fue bajo (D = 0.034), mientras que la distancia genética entre pares de poblaciones se incrementó con la distancia geográfica. En nivel poblacional, el efecto de la fragmentación no es evidente aún, lo cual podría
Birding for and with People: Integrating Local Participation in Avian Monitoring Programs within High Biodiversity Areas in Southern Mexico
Rubén Ortega-álvarez,Luis Antonio Sánchez-González,Vicente Rodríguez-Contreras,Víctor Manuel Vargas-Canales,Fernando Puebla-Olivares,Humberto Berlanga
Sustainability , 2012, DOI: 10.3390/su4091984
Abstract: Biological monitoring is a powerful tool for understanding ecological patterns and processes, implementing sound management practices, and determining wildlife conservation strategies. In Mexico, regional long-term bird monitoring has been undertaken only over the last decade. Two comprehensive programs have incorporated bird monitoring as the main tool for assessing the impact of human productive activities on birds and habitats at local and regional levels: the Integrated Ecosystem Management (IEM) and the Mesoamerican Biological Corridor Mexico (CBMM). These programs are implemented in supremely important biodiverse regions in the southern and southeastern states of Mexico. Bird monitoring activities are based on the recruitment and participation of local people linked to sustainable productive projects promoted by the CBMM or IEM. Through a series of training workshops delivered by specialists, local monitors receive equipment and coordinate to become part of a large monitoring network that facilitates regional covertures. This data currently being obtained by local people will enable the mid- and long-term assessment of the impacts of sustainable human productive activities on birds and biodiversity. Community-based bird monitoring programs are a promising opportunity for enhancing scientific knowledge, improving sustainable practices, and supporting wildlife conservation in areas of high biodiversity.
Dispersión de semillas por aves en un paisaje de bosque mesófilo en el centro de Veracruz, México: Su papel en la restauración pasiva
HERNáNDEZ-LADRóN DE GUEVARA,IVETTE; ROJAS-SOTO,OCTAVIO R; LóPEZ-BARRERA,FABIOLA; PUEBLA-OLIVARES,FERNANDO; DíAZ-CASTELAZO,CECILIA;
Revista chilena de historia natural , 2012, DOI: 10.4067/S0716-078X2012000100007
Abstract: seed dispersal by birds may play a major role in the successful natural forest restoration process as birds can deposit pioneer and primary seeds species, thereby defining the recovery of plant community composition over time. in this study, seed ingestion and dispersion by frugivorous birds were analyzed as processes facilitating the restoration of tropical cloud montane forests in central veracruz, mexico. birds were classified according to their affinity to the forest and their preference to a particular forest stratum, in order to determine whether these factors were related to the richness, abundance and diversity of ingested and dispersed seeds. we analyzed 93 fecal samples from 23 bird species. a total of 2699 seeds from 17 plant species were found in the fecal samples, the most abundant seed was from the shrub conostegia xalapensis. we analyzed the correlation between seed size and beak size for the six most frequently captured bird species. we also evaluated the effect of bird ingestion on seed germination by performing two experiments, the first one using the total number of seeds found in fecal samples, and the second one using c. xalapensis seeds that were administered artificially to the birds and their germination compared with control seeds. we found significant differences among the ingested seed diversity indexes for the most commonly captured birds, which supports a differential seed consumption and dispersion. however, there were no significant differences of the seed abundance and richness between birds with different forest affinity or forest stratum preference. also, there was no significant association between seed size and the height and the width of the beak, but there was a difference found in the length measured from the base and from the nostrils. from the total seed species, 59 % germinated from fecal samples belonging to 78 % of the bird species. as has been suggested for lowland tropical forests, this study also showed that in tropical
Dispersión de semillas por aves en un paisaje de bosque mesófilo en el centro de Veracruz, México: Su papel en la restauración pasiva Seed dispersal by birds in a cloud forest landscape in central Veracruz, Mexico: Its role in passive restoration
IVETTE HERNáNDEZ-LADRóN DE GUEVARA,OCTAVIO R ROJAS-SOTO,FABIOLA LóPEZ-BARRERA,FERNANDO PUEBLA-OLIVARES
Revista chilena de historia natural , 2012,
Abstract: La dispersión de semillas por aves puede jugar un papel determinante en el éxito de la restauración pasiva de los bosques ya que las aves pueden depositar semillas de especies pioneras y primarias, definiendo con ello la recuperación de la composición de la comunidad vegetal en el tiempo. En este trabajo se analizó la ingesta y dispersión de semillas por aves frugívoras como coadyuvantes en la restauración del bosque mesófilo de monta a en el centro de Veracruz, México. Las aves fueron clasificadas de acuerdo a su afinidad por el bosque y al estrato arbóreo en que concentran su actividad, con el fin de determinar si estas características se relacionan con la abundancia, riqueza y diversidad de las semillas que ingieren y dispersan. Se analizaron 93 excretas de 23 especies de aves; en ellas se encontraron 2699 semillas de 17 especies vegetales, siendo las más abundantes las del arbusto Conostegia xalapensis. Analizamos la correlación entre tama o de las semillas y tama o del pico para las seis especies de aves más capturadas. Complementariamente, evaluamos el efecto de la ingesta de semillas por aves sobre la germinación, realizando dos experimentos, uno con el total de las semillas obtenidas en las excretas, y otro con semillas de C. xalapensis que fueron administradas a las aves artificialmente y su germinación comparada con semillas control. Se encontraron diferencias significativas entre los índices de diversidad de semillas ingeridas para las seis especies de aves con mayor número de registros, lo que sugiere un consumo diferencial. Sin embargo, no se encontraron diferencias significativas en la riqueza y abundancia de semillas consumidas entre aves con diferente afinidad al bosque y preferencia de estrato arbóreo. Tampoco se observó una asociación significativa entre el tama o de semillas con el ancho y lo alto del pico, pero sí con la longitud tomada desde la base y desde los nostrilos del mismo. Del total de las especies de semillas encontradas, el 59 % germinó en las excretas del 78 % de las especies de aves. Este trabajo muestra que en los bosques mesófilos de monta a las aves son agentes dispersores importantes de especies de plantas pertenecientes a bosques secundarios y también dispersores de algunas plantas del bosque primario, por ello son agentes que facilitan el proceso de sucesión forestal. Seed dispersal by birds may play a major role in the successful natural forest restoration process as birds can deposit pioneer and primary seeds species, thereby defining the recovery of plant community composition over time. In this study, seed inge
Reactivity of 4-tert-Butyldimethylsiloxy-1,2,3,6-tetrahydropyridines with Hydrazines
Javier Figueroa,Esther Caballero,Pilar Puebla,Fernando Tomé,Manuel Medarde
Molecules , 2006, DOI: 10.3390/11110929
Abstract: The reactivity of 6-(nitrophenyl or trimethoxyphenyl)-4-tert-butyldimethyl- siloxy-1,2,3,6-tetrahydropyridine derivatives with hydrazines under acid conditions is described. The structure of the products isolated ? hydrazones, pyrazolines or pyridazinones ? depended on the conditions used. In addition, a systematic study of the reaction outcomes was carried out by introducing variations on the substituents of the tetrahydropyridine ring.
Bioavailability of iron bis-glycinate chelate in water
Olivares G,Manuel; Pizarro A,Fernando;
Archivos Latinoamericanos de Nutrición , 2001,
Abstract: iron amino acid chelate is being increasingly considered in programs for iron fortification of foods. the bioavailability of iron bis-glycinate chelate given in water was studied using a double-isotopic method in a group of 14 women. iron absorption from aqueous solutions of 15 mg/l of elemental iron as either iron bis-glycine chelate or ferrous ascorbate was not significantly different (34.6% and 29.9% respectively). standardized iron absorption of the iron bis-glycinate was 46.3% (standardized to 40% absorption of the reference dose). there was a significant correlations between (in) iron absorption of iron bis- glycinate chelate with (in) serum ferritin (r= -0.60, p <0.03) and with (in) iron absorption from ferrous ascorbate (r= 0.71, p<0.006), suggesting that iron bis-glycinate chelate absorption is indeed regulated by the iron stores of the body.
HIERRO Y ZINC EN LA DIETA DE LA POBLACION DE SANTIAGO
Pizarro A,Fernando; Olivares G,Manuel; Kain B,Juliana;
Revista chilena de nutrición , 2005, DOI: 10.4067/S0717-75182005000100002
Abstract: iron and zinc deficiency are the most prevalent nutritional deficiencies worldwide. in chile, only women of fertile age and pregnant women present significant prevalences of iron deficiency anemia. on the contrary, the majority of the population is at risk of zinc deficiency. furthermore, our country is experiencing an epidemiological transition, in which micromineral deficiencies and chronic non-communicable diseases such as obesity coexist simultaneously. iron and/or zinc deficiencies could be prevented by dietary improvement, food fortification or supplementation. food fortification is considered the most practical and sustainable way of preventing micromineral deficiencies. fortification could be addressed to the entire population (universal), to high risk groups (targeted) or voluntary, in which food producers add micronutrients to processed foods to increase the nutritional value of the products. it is recommended that the foods to be fortified do not contain high amounts of refined carbohydrates so as to prevent an increase in the intake of empty calories. recently, the efficacy of the voluntary fortification of dairy products, breakfast cereals and non-carbonated non-alcoholic beverages has been demonstrated. these last vehicles may be an alternative to increase zinc intake in our population as well as iron intake in high risk groups such as women of fertile age
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