ABSTRACT By condensing ethylene-1,2-diamine with different aldehydes such as benzaldehyde, 4-chloroacetophenone and 2-chlorobenzaldeyhde within 1:2 molar ratio, resulted new series of Schiff base ligands (L1)-(L3) containing bidentate nitrogen atom. Their metal complexes were synthesized by coordinating the ligands with transition metals as Co(II), Cu(II), Ni(II) and Zn(II) and exhibited octahedral geometry. Their characterization was done with the help of spectral, physical and analytical analysis. Spectral and elemental analysis of all bidentate ligands and their corresponding 3d-metal chelates was consistent with their proposed structures, signifying the high purity of these compounds. For in-vitro studies, these metal complexes along their ligands were screened against the six bacterial strains; Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus aureus and Streptococcus faecalis. Six fungal strains; Aspergillus niger, Trichophyton mentogrophytes, Epidermophyton floccosum, Trichophyton schoenleinii, Microscopum canis and Fusarium culmorum were used to study antifungal activity of the compounds. Bioactivity results exhibited that metal complexes showed higher antimicrobial potential as compared with their corresponding ligands. The enhanced activity resulted due to chelation that decreases the polarity of metal ions by complexing with bidentate ligands.

Abstract Let G = (V;E) be a graph. A total labeling ψ : V ⋃ E → {1, 2, ....k} is called totally irregular total k-labeling of G if every two distinct vertices u and v in V (G) satisfy wt(u) ≠wt(v); and every two distinct edges u 1 u 2 and v 1 v 2 in E(G) satisfy wt(u 1 u 2 ) ≠ wt(v 1 v 2 ); where wt(u) = ψ (u) + ∑ uv∊E(G) ψ(uv) and wt(u 1 u 2 ) = ψ(u 1 ) + ψ(u 1 u 2 ) + ψ(u 2 ): The minimum k for which a graph G has a totally irregular total k-labeling is called the total irregularity strength of G, denoted by ts(G): In this paper, we determine the exact value of the total irregularity strength of cubic graphs.

Abstract: Quantitative structure-activity relationships (QSAR) modelling on 30 N-Arylidenequinoline-3-carbohydrazides analogs was performed using Multi-Linear Regression (MLR) analysis adopting Genetic Function Algorithm (GFA) method. Semi empirical method using PM6 basis set was used for complete geometry optimization of the data set. The best model was chosen based on its statistical fit due to it good internal and external validations. From the Williams plot, it can be inferred that the reported model can make prediction of new compounds that are not within the data set. The molecular docking study showed that, the most active chemical in the data set was better than the standard β-glucuronidase inhibitor both in terms of binding scores and the amino acid residues that interacted with the drug and β-glucuronidase enzyme. The Pharmacokinetic studies indicated that none of the chemicals violated any of the condition set by the Lipinski′s Rule of five which confirm the bioavailability of these chemicals. The results these findings give room for designing novel β-glucuronidase inhibitors that are highly effective.

Resumen: Se llevó a cabo la técnica de QSAR en 30 analogos de N-arilidenequinolina-3-carbohidrazidas mediante el analisis de regresesión lineal múltiple (MLS) adopatando el método del algoritmo de función genética (GFA). Para la optimización completa de la geometría del conjunto de datos se utilizó un método semiémpirico del conjunto de bases PM6. El mejor modelo fue elegido basado en función de su ajuste estadístico debido a su validación interna y externa. A partir de la gráfica de Williams, se puede inferir que el modelo reportado puede predecir nuevos compuestos que no se encuentran en el conjunto de datos. Este estudio de acomplamiento molecular mostró que, el químico más activo del conjunto de datos fue mejor que el inhibidor estándar β-glucuronidasa, tanto en términos de unión y en términos de interacción de los residuos con el fármaco y la enzima β-glucuronidasa. Los estudios farmacocinéticos que indicaron que ninguno de los fármacos incumple ninguna de las condiciones establecidas por la regla de cinco de Lipinski, en donde se confirma la biodisponibilidad de estos químicos. Los resultados de los hallazgos computacionales permiten diseñar nuevos inhibidores de la β-glucuronidasa que son altamente efectivos.

Water resources have significant importance in countries with water scarcity. Part of this problem is attributed to the lack of relatedness between ecosystems service suppliers and users, and schemes of payment for hydrological ecosystem services (PHES) are emerging as a strategy to connect them. However, in the development of a scheme of PHES, one critical point is to find out if the protective land uses are adequately generating the service to sell. The aim of this study was to determine the hydrologic behaviour of land uses located in a hydrological recharge area of Sierra de Ocontepec. The land uses were secondary regeneration forest (SRF), African star grasslands (GWT), African star grasslands with shrubs (GS), disturbed Quercus oleoides forest (QF) and natural grasslands (NG). Indicators were precipitation, throughfall, runoff, soil moisture changes, evapotranspiration and percolation. Hydrological balances showed that percolation was higher in GWT (1 608 mm), GS (1 744 mm) and NG (1 314 mm), than in SRF (1 19 mm) and QF (974 mm). Results indicate that groundwater recharge during the study period generated adequate water shed services; however, the demand for piped water supply in the lowlands is at a maximum. This implies that the use of water should be regulated, more efficiently distributed, rather than relying on the increased availability.

Los recursos hidrológicos tienen significativa importancia en países con problemas de escasez de agua, parte de los cuales se atribuyen a la inexistencia de una relación entre los proveedores de servicios ambientales y de los usuarios. Los esquemas de pago por servicios ambientales hidrológicos (PSAH) surgen como una estrategia para conectarlos. El desarrollo de este esquema debería garantizar que los usos de la tierra de protección generen el servicio que se va a vender correctamente. Este estudio determinó el comportamiento hidrológico de los usos del suelo ubicados en un área de recarga de la Sierra de Otontepec, que correspondieron a: regeneración de bosques secundarios (SRF), pastizales estrella africana (GWT), pasto estrella africana y terrenos con arbustos (GS); bosque perturbado de Quercus oleoides (QF) y pastizales naturales (NG). Los indicadores fueron: precipitación, escorrentía, cambios de humedad del suelo, evapotranspiración y percolación. Los saldos hidrológicos mostraron que la percolación fue mayor en GWT (1 608 mm), GS (1 744 mm) y NG (1 314 mm), que en SRF (1 19 mm) y QF (974 mm). Los resultados indican que la recarga de agua subterránea durante el período de estudio proporcionó servicios ambientales hidrológicos convenientes, aun cuando la demanda del suministro de agua corriente en las tierras bajas está en un nivel máximo. Lo anterior implica que el uso del agua debe ser regulado y distribuido de manera más eficiente, en lugar de basarse en el aumento de la disponibilidad.

The Abutilon genus from the Malvaceae family is of medicinal importance, and members of this genus are distributed in the tropical and subtropical regions of Asia and other parts of the world. Abutilon pakistanicumJafri & Ali is mainly found in Pakistan. It has been used by different systems of traditional medicines to treat different diseases. Pakistamide C, a new sphingolipid, has been isolated from the ethyl acetate soluble fraction of the methanolic extract of A. pakistanicum. Different spectroscopic techniques such as NMR (1H, 13C, COSY, NOESY, HSQC, HMBC) and Mass spectrometry (EI-MS, and FAB-MS experiments) were used to elucidate the structure of pakistamide C.

Oxalis corniculata L. (creeping wood sorrel) is medicinally important member of family Oxalidaceae, and is distributed in the tropical and subtropical regions of the world. It has been used in different systems of traditional medications for different diseases. Corniculatin A, a new flavonoid glucoside, was isolated from the ethyl acetate soluble fraction of the whole plant along with luteolin, luteolin-7-O-β-D-glucoside and β-sitosterol-3-O-β-D-glucoside, This is the first report of these compounds from this species. Their structures were elucidated on the basis of spectral data including mass and 2D NMR experiments.

This study was conducted to assess the biocontrol efficacy of Bacillus subtilis (strain 4812) and Bacillus methylotrophicus (strain H8) individually or in combination with two plant defense inducers including Acetyl salicylic acid (ASA) and DL-Beta-aminobutyric acid (BABA) against tomato wilt caused by Ralstonia solanacearum. The pathogen was significantly inhibited by all treatments in the greenhouse and in vitro tests. The treatments H8+ASA and 4812+H8 were found to be the most effective treatments in in vitro tests. Applied on tomato seeds and as soil drenching, the disease was most inhibited by H8 whereas 4812+H8+ASA was the least effective treatment. High activity of phenylalanine ammonia-lyase was observed in the plants treated with 4812+H8, H8+ASA and 4812+H8+ASA. The highest expression of peroxidase and polyphenoloxidase enzymes was found in the plants treated with H8, 4812+H8 and H8+ASA. The result of real time PCR showed that concentration of the pathogen in stem tissues was significantly reduced in all treated plants and H8+ASA was the most effective treatment. This study revealed that combined application of Bacillus strains can be considered as a more effective biocontrol agent against tomato bacterial wilt. Furthermore, the synergistic effect of plant defense inducers was variable to different Bacillus strains.

In many tropical cattle farms of Central America, farmers commonly retain trees in pastures to obtain timber and provide shade and fodder to cattle. However, little is known about the diversity, abundance, richness and species composition of dispersed trees in pastures of cattle farms in the dry tropics. Therefore, the objective of this study was to characterize and describe the pattern of tree cover dispersed in pastures of cattle farm systems assessing their roles in sustaining farm productivity. The study was conducted in 16 cattle farms in a tropical dry ecosystem in Costa Rica. A total of 5,896 trees, from 36 families and 99 species, were found dispersed in pastures (836 ha). Trees were present on 100% of the farms and in 85% of pastures and they occurred as individual trees (54%) and clustered (46%). The most abundant families are Bignonaceae, Sterculeaceae and Boraginaceae. The most common tree species were Tabebuia rosea (Bertol.) DC, Guazuma ulmifolia Lam, Cordia alliodora (Ruiz & Pav.) Oken and Acrocomia acule ata (Jacq.) Lodd. ex Mart, which together accounted for 60% of the total number of trees. Tree species with smaller crowns are found at higher densities than tree species with large crowns. Pastures mean crown cover was 7% (SE ± 0.54) and mean tree density was 8.1 trees ha-1 (SE ± 0.66). We conclude that farmers are managing a low tree diversity, cover (m² ha-1) and density (trees ha-1) for fulfilling different farm needs that contribute to farm productivity but minimizing interference with pasture productivity.

Por lo general, la mayoría de los productores ganaderos de América Central retienen algunos árboles dispersos en los potreros para obtener beneficios adicionales a la ganadería tales como madera, alimentos, sombra y frutos para el ganado. Sin embargo, muy poco se sabe acerca de la diversidad, abundancia, riqueza, composición de las especies de árboles dispersos en las pasturas de ranchos ganaderos del trópico. Debido a esto, se planteo el siguiente estudio cuyo objetivo fue caracterizar y describir la cobertura de árboles dispersos en los potreros de ranchos ganaderos y el papel que juegan estos en la productividad del rancho. El estudio se realizó en 16 ranchos ganaderos en un ecosistema tropical seco de Costa Rica. Se encontró un total de 5,896 árboles dispersos en las pasturas (836 ha) pertenecientes a 36 familias y 99 especies. Los árboles estuvieron presentes en el 100% de los ranchos y en el 85% de los potreros. Se encontraron árboles individuales (54%) o formando grupos (46%). Las familias de árboles más abundantes encontradas fueron Bignonaceae, Sterculeaceae y Boraginaceae mientras que las especies más comunes encontradas fueron Tabebuia rosea (Bertol.) DC, Guazuma ulmifolia Lam, Cordia alliodora (Ruiz & Pav.) Oken y Acrocomia aculeata (Jacq.) Lodd. ex Mart, las cuales representan cerca del 60% del total de árboles dispersos encontrados en los potreros. Se encontró que las especies de árboles con dosel pequeño se encuentran en mayor abundancia que aquellas con dosel grande. La cobertura arbórea de los potreros fue del 7% (SE ± 0.54) mientras que la densidad fue de 8.1 árboles ha-1 (SE ± 0.66). Se concluye que los productores mantienen una baja diversidad (m² ha-1), cobertura (%) y densidad (árboles ha-1) para satisfacer diferentes necesidades de tal forma que contribuyan a incrementar la productividad del rancho pero minimizando la interferencia con la producción de pasto.

En Centro América, los paisajes agropecuarios mantienen diferentes formas de cobertura arbórea como árboles dispersos, cercas vivas, fragmentos de bosque, bosques ribereños, que pueden generar hábitats apropiados para la conservación de la biodiversidad. El presente estudio caracterizó la composición, riqueza y abundancia de mariposas en dos tipos de cercas vivas presentes en un paisaje dominado por pasturas en el Pacifico Central de Costa Rica. Se seleccionaron un total de cinco cercas vivas por cada tipo de cerca (simples y multiestrato), donde se establecieron franjas de 120x5m que fueron recorridos por espacio de una hora durante dos días/hábitat. Se registró un total de 2 782 individuos, pertenecientes a 75 especies de mariposas. Las especies más abundantes fueron: Anartia fatima, Eurema daría, E. nise, Hermeuptychia hermes, Junonia evarete y Phoebis philea. Las cercas vivas multiestrato presentaron una mayor riqueza y abundancia de especies de mariposas que las cercas vivas simples. Las cercas vivas multiestrato pueden ayudar a mantener el 56% de las especies encontradas en los bosques secundarios y ribereños. Este tipo de cerca viva pueden jugar un papel importante para la conservación de mariposas en áreas de producción pecuaria, y su beneficio está influenciado por el tipo manejo que realizan los productores.

Do live fences help conserve butterfly diversity in agricultural landscapes? In Central America, natural forests have been transformed into agriculture production areas, generating forest fragmentation, desertification, erosion and loss of biodiversity, among other concerns. Different tree cover compositions are kept on these agricultural landscapes, including scattered trees in pastures, live fences, fragments of secondary forests, and riparian forests. These can help in biodiversity conservation because they generate shelter, feeding and reproduction areas, among others. We studied the composition, richness and abundance of diurnal butterflies on two types of live fences in a landscape where pastures are predominant in Costa Rica’s Central Pacific Region. Transects (120x5m) were observed for an hour (two days/habitat) in five multi-strata fences (with several plant species, strata and canopy width) and five simple fences (with smaller and pruned trees). A total of 2 782 butterflies were observed (75 species). The most abundant species were Anartia fatima, Eurema daria, Eurema nise, Hermeuptychia hermes, Junonia evarete and Phoebis philea. Multi-strata fences had more species and can help maintain 56% of the total species observed in secondary and riparian forests. This type of live fence can play an important role in butterfly conservation in livestock areas, and its benefits are influenced by the manner in which farmers manage their land. Rev. Biol. Trop. 58 (1): 447-463. Epub 2010 March 01.

La cobertura arbórea en pasturas contribuye a mejorar la productividad animal por medio de la reducción del estrés calórico, además de sus beneficios hacia la conservación del suelo y la biodiversidad. El presente estudio tuvo como objetivo conocer el efecto de la cobertura arbórea sobre la disponibilidad del pasto Brachiaria brizantha. Se llevo a cabo un inventario de árboles en 53 potreros y se seleccionaron las 12 especies más abundantes para el monitoreo de la disponibilidad de pasto bajo la copa y a pleno sol. También, se determinó la relación entre la cobertura arbórea y la disponibilidad de pasto. La disponibilidad de pasto bajo sombra mostró reducciones entre 4 a 97% en comparación a pastura abierta, excepto la especie Acrocomia aculeata que tuvo una mayor disponibilidad bajo sombra (9%). Fue evidente que conforme se incrementa la cobertura arbórea en pasturas se deprime la disponibilidad de pasto. Se concluye que la disponibilidad de pasto bajo la copa de árboles varía entre especies y que existe una relación negativa entre cobertura arbórea en pasturas y disponibilidad de pasto.

The tree cover in pastureland contribute to improve the animal productivity through reducing the heat stress, and also benefits the soil conservation and biodiversity. The objective of this study was to know the effects of tree crown cover on the availability of Brachiaria brizantha grass. A census of trees in 53 plots was taken out and there were selected the 12 most abundant in pastureland for monitoring the grass availability under the canopy and in open pasture. Also, there was determined the relationship between tree cover and grass availability. Beneath canopy the grass availability showed reductions between 4 and 97% when compared to open pasture, except for Acrocomia aculeata specie which was higher under canopy (9%). The grass availability was reduced according to increasing the tree crown cover in pastureland. It is concluded that grass availability under tree canopy varied among species and there was a good negative relationship between crown cover percentage and grass availability.

Se evaluó el impacto de sistemas silvopastoriles sobre el recurso hídrico en zonas de recarga de la subcuenca del río Jabonal, Costa Rica. Los sistemas que se evaluaron fueron pasturas nativas sobrepastoreadas (PD), pasturas nativas con árboles (PNA), pasturas mejoradas con árboles (PMA) y un bosque secundario intervenido (BSI). Se caracterizó la vegetación de los sistemas evaluados y se estimó la escorrentía superficial e infiltración. La PD presentó la mayor escorrentía, seguida por la PNA; mientras que la PMA y el BSI presentaron los valores más bajos (28, 27, 15 y 7%, respectivamente). El BSI presentó la mayor infiltración; mientras que las pasturas con árboles (PMA y PNA) permitieron infiltrar más que las PD (3,54 0,23 0,19 y 0,07 cm/h, respectivamente). La cobertura arbórea se correlacionó negativamente con la escorrentía (r = -0,71; P=0,01) y positivamente con la infiltración (r = 0,75; P=0,01). Los sistemas silvopastoriles, al tener el componente arbóreo, mostraron mayores beneficios hidrológicos en la zona de recarga, ya que disminuyeron la escorrentía superficial e incrementaron la infiltración, favorecieron a una mayor conservación de agua en el suelo.

The impact of silvopastoral systems on water resources in the recharge zone of sub-watershed of Jabonal river, Costa Rica, was evaluated. The evaluated systems were overgrazed native pasture (ONP), native pastures with trees (NPT), improved pastures with trees (IPT), and managed secondary forest (MSF). The vegetation of the evaluated systems was characterised and the runoff and infiltration were estimated. The ONP presented the highest runoff, followed by NPT, whereas IPT and MSF had the lowest values (28, 27, 15 y 7%, respectively). The MSF presented the highest infiltration, whereas pastures with trees (IPT and NPT) allowed higher infiltration rates than ONP (3.54, 0.23, 0.19 and 0.07 cm/h, respectively). The cover tree was negatively correlated with runoff (r = -0.71; P=0.01) and positively with infiltration (r = 0.75; P=0.01). The silvopastoral systems, which have tree components, showed better hydrological benefits in the recharge zone due to a decreased on the runoff and increased infiltration, causing a better conservation of water in soil.

Los sistemas silvopastoriles son tecnologías ganar-ganar, generan servicios ambientales, incrementan la productividad y son medios para retener árboles en paisaje agrícolas. Dos estudios fueron conducidos en fincas activas en Cañas, Guanacaste, Costa Rica, localizadas en un bosque seco tropical. El primer estudio midió la disponibilidad de dos especies de pastos contrastantes creciendo con especies nativas de árboles, mientras que el segundo estimó la producción de frutos de las cuatro especies arbóreas dispersas más abundantes en las pasturas. La producción de pasto de Brachiaria brizantha fue casi tres veces mayor a la de Hyparrhenia rufa (14,7 vs. 5,3 t MS ha-1 año-1), lo cual explica porque los productores están cambiando especies nativas por especies mejoradas. La producción de ambas pasturas no fue influenciada por las especies arbóreas ni por la posición respecto a la copa de los árboles (10,7 vs. 9,0 t MS ha-1 año-1 para bajo y zona intermedia de copa, respectivamente). Enterolobium cyclocarpum produjo entre 3 y 10 veces más frutos que las otras especies. La calidad de frutos fue mayor en especies leguminosas (E. cyclocarpum y Pithecellobium saman) que en no leguminosas. Sin embargo, la combinación de especies de árboles podría proveer al ganado de adicionales recursos forrajeros de alta calidad que el pasto, reduciendo así el uso de alimentos comerciales. Este estudio concluye que la introducción de árboles nativos (incluyendo frutales) en pasturas puede incrementar la producción de pasto y oferta de frutos forrajeros de alta calidad en épocas limitantes para la alimentación del ganado.

Silvopastoral systems are considered win-win technologies: provide environmental services, increase cattle farm productivity, and are means to retain trees in agricultural landscapes. Two studies were conducted in active cattle farms in Cañas (Guanacaste, Costa Rica), located in tropical dry forest areas. The first study measured the availability of two contrasting grass species covered with native tree species, whereas the second study estimated fruit production of four most abundant tree species dispersed in pastures in the study zone. Brachiaria brizantha grass production was almost three times greater than that produced by Hyparrhenia rufa (14.7 vs. 5.3 t DM ha-1 yr-1) which may explain why farmers are changing native grass species by more productive grass species. Annual grass production of both grass species was not influenced significantly by tree species neither by the position respect to crown tree (10.7 vs. 9.0 t DM ha-1 yr-1 for under and intermediate crown areas, respectively). Enterolobium cyclocarpum trees produced between 3 and 10 times more fruits than the other tree species. Fruit quality was higher in leguminous tree species (E. cyclocarpum and Pithecellobium saman) compared to the non leguminous tree species. However, the combination of tree species could provide cattle with additional fodder sources of higher nutritive quality that grasses reducing the use of commercial feed. This study conclude that the introduction of native trees (including fruit trees) in grasslands may increase grass productivity and offer high quality fodder fruits in limiting seasons for feeding cattle.

El objetivo de este estudio fue hacer un análisis financiero en el corto plazo y calcular indicadores de rentabilidad de inversiones en el largo plazo, en tres prototipos de finca ganadera con escenarios de riesgo e incertidumbre. Se analizaron 33 fincas ganaderas de doble propósito del Pacífico Central de Costa Rica mediante una encuesta de indicadores socioeconómicos, tecnológicos, financieros, de diferentes estrategias de alimentación animal. Mediante un análisis de conglomerados se identificaron tres grupos: sistema eco-amigable (SEA); sistemas intensivos convencionales (SIC) y sistema extensivo tradicional (SET). El análisis beneficio-costo se realizó en tres fincas tipo de cada conglomerado. El tipo SIC fue el más rentable (VAN: $US4314). Los tres modelos mostraron alta sensibilidad a los cambios en los precios de la leche. Las variaciones en los costos de insumos y mano de obra develan una mayor inelasticidad expresada en los bajos valores de la pendiente de las ecuaciones (SET = 717.9; SIC = 6168.9; SEA = 1535.7). La simulación que incorpora riesgo sugirió al modelo SEA como el más beneficiado cuando se mejora la alimentación de los animales. El incremento en la rentabilidad en los tres prototipos al introducir recursos endógenos en el sistema de alimentación constituyó un estímulo para avanzar en un modelo de intensificación, menos dependiente de insumos externos y amigable con el ambiente.

The objective of this study was to carry out a financial analysis in the short time, and to calculate profit indicators of the investments on the long time in three livestock prototypes farms, under risk scenarios. 33 livestock dual purpose farms from central pacific area of Costa Rica were analyzed, using a survey of topics related to socioeconomic, technological, and financial indicators of different animal feeding strategies. By cluster analysis three groups were identified: eco-friendly system (SEA); intensive conventional system (SIC) and extensive traditional system (SET). A benefit-cost analysis was carried out in 3 prototype farms that represent each one of the defined clusters. SIC type was the most profit (VAN: $US4314). The three models showed a high sensibility to the changes in the prices of the milk, expressed in the value of the slope of the equation (SET = 717.9; SIC = 6168.9; SEA = 1535.7). Variations in the costs of inputs and labor showed a bigger inelasticity expressed in the low values of the slope of the equations. Risk analysis simulation suggested that the type SET will be more beneficiated with the improvements of the feeding systems. Increase in financial profit of the three types of farm, by mean introduce improvements in the livestock feeding systems with on endogenous feeding resources, constitute an stimulate for advancing in the dissemination process of a feeding-intensification model either less dependents from external inputs and eco-friendly.