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Sample records for leucaena leucocephala basada

  1. Soil Solution Phosphorus Status and Mycorrhizal Dependency in Leucaena leucocephala.

    Science.gov (United States)

    Habte, M; Manjunath, A

    1987-04-01

    A phosphorus sorption isotherm was used to establish concentrations of P in a soil solution ranging from 0.002 to 0.807 mug/ml. The influence of P concentration on the symbiotic interaction between the tropical tree legume Leucaena leucocephala and the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum was evaluated in pot experiments. The level of mycorrhizal infection in Leucaena roots increased as the concentration of P was raised from 0.002 to 0.153 mug/ml. Higher levels of P depressed mycorrhizal infection, but the level of infection never declined below 50%. Periodic monitoring of P contents of Leucaena subleaflets indicated that significant mycorrhizal activity was detected as early as 17 days after planting, with the activity peaking 12 to 16 days thereafter. The highest level of mycorrhizal activity was associated with a soil solution P level of 0.021 mug/ml. Even though the mycorrhizal inoculation effect diminished as the concentration of P in the soil solution was increased, mycorrhizal inoculation significantly increased P uptake and dry-matter yield of Leucaena at all levels of soil solution P examined. The concentration of P required by nonmycorrhizal L. leucocephala for maximum yield was 27 to 38 times higher than that required by mycorrhizal L. leucocephala. The results illustrate the very high dependence of L. leucocephala on VAM fungi and the significance of optimizing soil solution phosphorus for enhancing the benefits of the VAM symbiosis.

  2. Antioxidant and tyrosinase inhibitor from Leucaena leucocephala

    African Journals Online (AJOL)

    gabriel

    2012-09-25

    Sep 25, 2012 ... and Chung-Yi Chen ... both synthetic (Lee et al., 2009; Liu et al., 2009) and ... Leucaena leucocephala is a leguminous plant which is ... et al., 2000). ..... Li et al. 14185. Nakatani Y, Ourisson G, Beck JP (1981). Chemistry and ...

  3. STUDIES ON SOME PHYSICOCHEMICAL PROPERTIES OF LEUCAENA LEUCOCEPHALA BARK GUM

    Directory of Open Access Journals (Sweden)

    Vijetha Pendyala

    2010-06-01

    Full Text Available Gum exudates from Leucaena Leucocephala (Family: Fabaceae plants grown all over India were investigated for its physicochemical properties such as pH, swelling capacity and viscosities at different temperatures using standard methods. Leucaena Leucocephala bark gum appeared to be colorless to reddish brown translucent tears. 5 % w/v mucilage has pH of 7.5 at 28°C. The gum is slightly soluble in water and practically insoluble in ethanol, acetone and chloroform. It swells to about 5 times its original weight in water. A 5 %w/v mucilage concentration gave a viscosity value which was unaffected at temperature ranges (28-40°C. At concentrations of 2 and 5 %w/v, the gum exhibited pseudo plastic flow pattern while at 10 %w/v concentration the flow behaviour was thixotropic. The results indicate that the swelling ability of Leucaena Leucocephala (LL bark gum may provide potentials for its use as a disintegrant in tablet formulation, as a hydro gel in modified release dosage forms and the rheological flow properties may also provide potentials for its use as suspending and emulsifying agents owing to its pseudo plastic and thixotropic flow patterns.

  4. Thyroxine (T 4-RIA) and triiodothyronine (T 3-RIA) serum levels in sheep fed on Leucaena Leucocephala; Niveis sericos de tiroxina (T4-RIA) e triiodotinonina (T3-RIA) em ovinos alimentados cm Leucaena Leucocephala LAM

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa, J M; Rodriguez, N M [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Escola de Veterinaria; Cardoso, W M [Maranhao Univ., Sao Luis, MA (Brazil). Escola de Medicina Veterinaria; Velez, C E.S.

    1988-12-31

    The aim of this work is to study the toxicity of Leucaena leucocephala on thyroxine and triiodothyronine serum concentration. Results indicate that ovine T 4 and T 3 serum levels do not decrease with Leucaena leucocephala feeding, sohen proreided for 41 days. (author). 10 refs, 1 tab.

  5. The flavonoid constituents of Leucaena Leucocephala growning in ...

    African Journals Online (AJOL)

    ... Leucaena leucocephala were identified as Caffeic acid, Isorhamnetin, Chrysoeriol, Isorhamnetin 3-O-galactoside, Kaempferol-3-O-rubinoside, Quercetin-3-O-rhamnoside and Luteolin-7-glucoside. Chemical structures of the isolated compounds were identified by TLC, PC and spectral techniques (UV, 1H -NMR and MS).

  6. Valor nutritivo e utilização do feno de leucena (Leucaena leucocephala cv. Cunningham para coelhos em crescimento Nutritional feeding value and use of Leucaena hay (Leucaena leucocephala cv. Cunningham for growing rabbits

    Directory of Open Access Journals (Sweden)

    Denise Fontana Figueiredo

    2000-05-01

    Full Text Available Dois experimentos foram realizados com o objetivo de avaliar a utilização do feno de leucena (Leucaena leucocephala cv.Cunningham para coelhos em crescimento. No ensaio de digestibilidade foram utilizados 28 coelhos da raça Nova Zelândia Branco, com 40 dias de idade, distribuídos em um delineamento experimental inteiramente casualizado, com dois tratamentos e 14 repetições. Foram utilizadas duas dietas, uma referência e uma teste na qual o feno de leucena substituiu 25% da matéria seca da dieta-referência. Os teores de matéria seca digestível, matéria orgânica digestível, proteína digestível, fibra em detergente neutro digestível e energia digestível do feno de leucena foram, respectivamente, de 26,87%; 25,30%; 5,32%; 14,66% e 1.286Kcal/kg. No experimento de desempenho foram utilizados 80 coelhos da raça Nova Zelândia Branco, de 35 a 70 dias de idade. Os animais foram distribuídos num delineamento experimental inteiramente casualizado, com cinco tratamentos (cinco níveis de inclusão de feno de leucena: 0, 25, 50, 75 e 100%, em substituição ao feno de alfafa, oito repetições e dois animais por unidade experimental. Os níveis crescentes de substituição do feno de alfafa pelo feno de leucena, não afetaram o desempenho dos coelhos durante o período experimental. Os dados mostram que o feno de leucena substituiu eficientemente o feno de alfafa em dietas para coelhos em crescimento.Two trial were carried out to determine the performance of rabbits fed on diets which included Leucaena hay (Leucaena leucocephala cv. Cunninghan. Twenty-eight 40-day old White New Zealand rabbits were employed for the digestibility trial, in a completely randomized design with two treatments and 14 replications. Reference and test diets were used in which Leucaena hay replaced 25% of the dry matter in the reference diet. Digestible dry matter, digestible organic matter, digestible protein, digestible F.D.N. and digestible energy contents of

  7. Preliminary note on strength properties of Leucaena leucocephala from lalkua, Tarai Bhabar Forest Division, uP

    Energy Technology Data Exchange (ETDEWEB)

    Shukla, N.K.

    1982-03-01

    Based on physical and mechanical tests conducted on small clear specimens, the strength properties of Leucaena leucocephala in green condition are reported and compared with Fraxinus micrantha, Morus alba and Tectona grandis. In general, Leucaena leucocephala has given slightly lower strength properties except in some cases as compared to above species. (Refs. 6).

  8. Thyroxine (T 4-RIA) and triiodothyronine (T 3-RIA) serum levels in sheep fed on Leucaena Leucocephala

    International Nuclear Information System (INIS)

    Pessoa, J.M.; Rodriguez, N.M.; Cardoso, W.M.; Velez, C.E.S.

    1988-01-01

    The aim of this work is to study the toxicity of Leucaena leucocephala on thyroxine and triiodothyronine serum concentration. Results indicate that ovine T 4 and T 3 serum levels do not decrease with Leucaena leucocephala feeding, sohen proreided for 41 days. (author). 10 refs, 1 tab

  9. Nitrogen fixation and effects of pruning on Gliricidia sepium and Leucaena leucocephala

    International Nuclear Information System (INIS)

    Liyanage, M.S. de

    1998-01-01

    This 7-year study examined genetic variability in N 2 fixation by Gliricidia sepium and the N 2 -fixing capacity in G. sepium and Leucaena leucocephala as influenced by frequency of pruning, age, and shade from coconut. The 15 N-dilution method was used with the non-nodulating tree legume Senna siamea as the non-fixing reference. There were significant differences in total dry matter, N yield and N 2 -fixation capacity among four G. sepium provenances. Gliricidia had higher values than Leucaena for dry matter, N yield, and amount of N fixed; %Ndfa was comparable in both species (47-55%). A substantial amount (18%) of fixed N 2 was present in the roots of both species. In a long-term study aimed at comparing the effect of pruning practices and age of trees, G. sepium grown under coconut outperformed L. leucocephala in terms of dry matter, N yield and amounts of N 2 fixation. Coconut saplings supplied with G. sepium and L. leucocephala prunings as green manure grew better than those supplied with S. siamea; the fraction of coconut-sapling N obtained from Gliricidia and Leucaena was 40 and 36%, respectively. These results suggest that G. sepium, which demonstrated a high potential for biomass production and N 2 fixation, is appropriate for interplanting with coconut palms. Also, S. Siamea was found to be a suitable reference species. (author)

  10. Analisis Karbohidrat, Protein, dan Lemak pada Pembuatan Kecap Lamtoro Gung (Leucaena leucocephala terfermentasi Aspergillus oryzae

    Directory of Open Access Journals (Sweden)

    TJAHJADI PURWOKO

    2005-05-01

    Full Text Available Leucaena leucocephala was one of Mimosaceae family which had high protein content nearly the same value as in Soya beans protein content. L. leucocephala could be used as the substitution of Soya beans in production of soy sauce. Soy sauce was one of fermentation liquid products which had flavor and aroma as meat, and had high nutrition value. The aims of the research were (i to analyze nutrition value in seeds, koji and moromi including carbohydrate, proteins and lipids and (ii to know the potency of L. leucocephala as raw material in production of soy sauce by fermentationmethod with Aspergillus oryzae as inoculums. Fermentation was one of soy sauce production processes that involved two steps: (i the solid stage fermentation and (ii the brine fermentation. L. leucocephala was fermented with A. oryzae for 3-5 days to produce koji. Koji was soaked in salt solution 20% (1:5 b/v then it was fermented for 30 days to produce moromi. Nutritional values in L. leucocephala seeds, koji, and moromi was analyzed, i.e. carbohydrate (sugar reduction and starch, protein, and lipids. Moromi filtrate was added by spices to Leucaena sauce. Finally, preferable Leucaena sauce was tested including flavor, aroma, and color. Preferable data was analyzed by non-parametric statistic; it was Friedman Test and followed Wilcoxon Ranking Method. The result showed that value of reducing sugar in L. leucocephala seeds, koji and moromi were 78.38 mg/g; 119.08 mg/g; and 164.29 mg/g. Starch value of seeds, koji and moromi were 274.36 mg/g; 260.92 mg/g and 179.50 mg/g. The value of dissolved protein in seeds, koji and moromi were 107.44 mg/g; 86.1 mg/g; and 208.56 mg/g. The value of lipids on seeds, koji and moromi was 158.87 mg/g; 51.35 mg/g; and 80.86 mg/g. The data of preferable test on Leucaena sauce’s taste was the same as ABC sauce but the aroma of Leucaena sauce had the lowest score than the others. More over, the four kinds of sauce were not different significantly

  11. Leucaena leucocephala IN RUMINANT NUTRITION

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    M. Barros-Rodríguez

    2014-08-01

    Full Text Available It is a common situation in extensive ruminant production systems in tropical countries to have low production indicators due to nutrient deficiencies in the diet. An economic alternative to increase animal production is the incorporation of legumes (fodder and fruits in the diet. This review, presents an analysis of the positive and negative effects of Leucaena leucocephala consumption by ruminants, with particular emphasis on the secondary compound mimosine. Leucaena due to its high nutrient content, rumen by-pass protein supply and its possible effect on the reduction of greenhouse gas (attributed to tannins has become one of the legumes most commonly used in ruminant feeding practices. However, in countries where leucaena has been introduced, its use is still limited to levels below 30% inclusion in the diet, due to the secondary compound mimosine and its isomers (3,4 and 2,3 DHP, which can induce toxicity, even when animals are inoculated with rumen fluid containing the bacteria Synergistes jonesii reported as responsible for degrading these compounds in the rumen. In the Yucatan Peninsula, Mexico, ruminants consuming leucaena can tolerate more than 50% inclusion in the diet, without having a negative impact on production, attributed intake to mimosine and its isomers. We conclude that in animals not adapted, the intake would be limited to low inclusion levels (less than 30% inclusion in the diet, mainly because of mimosine and its derivatives. The decrease in intake or diet digestibility seem to better explain the reduction in methane production, however, in vivo studies are required to clearly establish the mechanism of action. It has been reported the presence of different bacteria to S. jonessi that would have the ability to degrade mimosine and its derivatives, however, the activity of these bacteria and its effectiveness must be confirmed in vivo.

  12. Effect of cutting height and frequency on Leucaena leucocephala ...

    African Journals Online (AJOL)

    Leucaena leucocephala is a fast-growing tree that can provide both high quality forage and firewood. The objective of this trial was to determine the optimum height and frequency of cutting for both wood and forage production. Cutting heights at 0.3m, 0.6m and 1.0 m were superimposed on 3-month and 6-month cutting ...

  13. CARACTERIZACIÓN DE DIEZ CULTIVARES FORRAJEROS DE Leucaena leucocephala BASADA EN LA COMPOSICIÓN QUÍMICA Y LA DEGRADABILIDAD RUMINAL

    OpenAIRE

    García M, Danny; Hilda, Wencomo G; Gonzáles C, Miriam; Medina R, María; Cova O, Luis

    2008-01-01

    Objetivo. Estudiar las variaciones en la composición química y la degradabilidad ruminal de diez cultivares de Leucaena leucocephala Lam. de Wit. mediante el análisis de componentes principales (ACP). Materiales y métodos. Se tomaron muestras durante tres años para evaluar la composición química, los niveles de metabolitos secundarios y la degradabilidad ruminal en ovinos. Los datos fueron analizados con el paquete estadístico SPSS y mediante el diagrama tridimensional se obtuvieron las agrup...

  14. Ithome lassula Hodges (Lepidoptera: Cosmopterigidae, una nueva especie para Cuba asociada a Leucaena leucocephala (Lam. de Wit

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    O Alonso

    Full Text Available El nuevo informe para Cuba de Ithome lassula Hodges (Lepidoptera: Cosmopterigidae, especie asociada a la planta forrajera Leucaena leucocephala, se confirmó con la identificación de los adultos, mediante la utilización de una clave basada en la maculación de las escamas en la zona de la cabeza del insecto. Los adultos emergieron en el laboratorio, de las larvas colectadas en las inflorescencias; estas procedían de los diferentes sistemas ganaderos que se muestrearon en las provincias Matanzas y Mayabeque, los cuales estaban compuestos indistintamente por las cuatro variedades comerciales de la leguminosa y por gramíneas pratenses. Por otra parte, la detección de las lesiones que causaron las larvas de este cosmopterígido en las inflorescencias, y su repercusión en la producción de semillas de leucaena, constituyó el elemento más importante que se debía considerar para valorar su potencialidad como plaga y al estimar las posibles pérdidas en los sistemas ganaderos evaluados.

  15. Management and quantification of nitrogen fixation in Leucaena leucocephala

    International Nuclear Information System (INIS)

    Safo, E.Y.

    1998-01-01

    The effects of pruning and age on N 2 fixation were studied using Leucaena leucocephala isoline K28, with Cassia siamea as the non-N 2 -fixing reference species, at a site of degraded soil fertility typical of much of the farming land in Ghana. The 15 N-dilution method was used to estimate N2 fixation. Cassia siamea consistently produced higher total biomass and total N yields than did L. leucocephala. The mean value for the fraction of N derived from fixation (%Ndfa) was higher for pruned L. leucocephala (36%) than for unpruned trees (18%). There was some underestimation of N 2 fixation as a result of using C. siamea as the reference, and because root N-contents were not determined. Strong, significant linear correlations were observed between foliar and whole-tree (weighted average) percent 15 N atom excess in unpruned L. leucocephala and C. siamea, suggesting that foliar 15 N enrichment can be used to accurately estimate %Ndfa. The results demonstrated that the 15 N-enrichment methodology can provide meaningful estimates of %Ndfa and total N 2 fixed for mixed tree plantations under field conditions, when adequate spacing is provided. (author)

  16. Estimation of nitrogen fixation in Leucaena leucocephala using 15N-enrichment methodologies

    Science.gov (United States)

    John A. Parrotta; Dwight D. Baker; Maurice Fried

    1994-01-01

    An estimation of biological nitrogen fixation by Leucaena leucocephala (Lam.) de Wit in monoculture and mixed-species plantations (with Casuarina equisetifolia L. ex J.R. & G. Forst., and Eucalyptus robusta Sm.) was undertaken over a two-year period in Puerto Rico using the 15N-enrichment...

  17. Changes in dinitrogen fixation in maturing stands of Casuarina equisetifolia and Leucaena leucocephala

    Science.gov (United States)

    John A. Parrotta; Dwight D. Baker; Maurice Fried

    1996-01-01

    Biological dinitrogen fixation in Casuarina equisetifolia J .R. & G. Forst. and Leucaena leucocephala (Lam.) de Wit was evaluated using the 15N-enrichment technique under field conditions in single-species and mixed-species plantings (with a nonfixing reference species, Eucalyptus X ...

  18. Nitrogen fixation in Leucaena leucocephala and effects of pruning s on cereal yields

    International Nuclear Information System (INIS)

    Bekunda, M.

    1998-01-01

    Leucaena leucocephala was interplanted with reference tree species, Cassia siamea and Cassia spectabilis, and estimates of percent N derived from N 2 fixation (%Ndfa) were made, by the isotope-dilution method, at 4, 6, 14, 20 and 30 months after transplanting. The %Ndfa values were low and variable throughout the growth period, except after thinning at 14 months when there was a five-fold increase. The two non-fixing reference species outperformed the N 2 -fixing Leucaena in above-ground vegetative production, and provided different fixed-N estimates. Prunings from the L. leucocephala and C. Siamea trees were applied separately to soil as green manure. Maize was planted to test the effects of the Leucaena green manure on soil fertility, and millet was the test crop for the Cassia. Whether surface-applied or incorporated, the prunings significantly improved yields, which were generally similar among rates and methods of application. The proportions of cereal N obtained from prunings ranged from 8 to 33%, with no cereal-yield correlation. The data indicate that multipurpose tree prunings are of potential use to farmers as organic sources of nutrients, even at relatively low application rates, without need for incorporation into the soil. (author)

  19. Utilización de la leucaena leucocephala como suplemento en cabras en crecimiento

    OpenAIRE

    Clavero, Tyrone; Razz, Rosa

    2009-01-01

    Con el objeto de evaluar el crecimiento de cabras mestizas (Nubian x Criollo) suplementadas con Leucaena leucocephala, se realizó un ensayo en el Occidente de Venezuela en una zona caracterizada como Bosque muy Seco Tropical. Se evaluaron tres raciones: T1 (pastoreo en gramínea-Cenchrus cillaris), T2 (pastoreo en gramínea + 2 h/día en Leucaena), T3 (pastoreo en gramínea + alimento concentrado comercial, 300 g/animal/día). El diseño experimental fue de bloques completamente al azar. El peso de...

  20. Caracterización de diez cultivares forrajeros de Leucaena leucocephala basada en la composición química y la degradabilidad ruminal

    OpenAIRE

    García M., Danny; Wencomo G., Hilda; González C., Miriam; Medina, María; Cova O., Luis

    2008-01-01

    Objetivo. Estudiar las variaciones en la composición química y la degradabilidad ruminal de diez cultivares de Leucaena leucocephala Lam. de Wit. mediante el análisis de componentes principales (ACP). Materiales y métodos. Se tomaron muestras durante tres años para evaluar la composición química, los niveles de metabolitos secundarios y la degradabilidad ruminal en ovinos. Los datos fueron analizados con el paquete estadístico SPSS y mediante el diagrama tridimensional se obtuvieron las agrup...

  1. Ovarian activity and estrus behavior in early postpartum cows grazing Leucaena leucocephala in the tropics.

    Science.gov (United States)

    Bottini-Luzardo, Maria; Aguilar-Perez, Carlos; Centurion-Castro, Fernando; Solorio-Sanchez, Francisco; Ayala-Burgos, Armin; Montes-Perez, Ruben; Muñoz-Rodriguez, David; Ku-Vera, Juan

    2015-12-01

    The legume Leucaena leucocephala (Leucaena) is widely used to supplement forage in silvopastoral livestock systems in Latin America. Little is known about its possible effects on the cow reproductive dynamic. The aim was to evaluate the effect of Leucaena foliage intake on re-establishment of ovarian activity and estrus behavior in early postpartum (7-90 days) cows. Twenty-four multiparous Bos taurus × Bos indicus cows were divided into two homogenous groups and assigned to one of two treatments: a silvopastoral system (SS, n = 12), consisting of an association of Cynodon nlemfuensis grass and L. leucocephala; and a control system (CS, n = 12), consisting of C. nlemfuensis alone. Intake of Leucaena in the SS ranged from 3.80 to 6.43 kg DM/cow/day. Plasma mimosine concentrations ranged from 1270 to 1530 μg/mL, and those for 2,3-dihydroxypyridine (DHP) from 147 to 729 μg/mL. No 3,4-DHP was detected in plasma. No difference (P > 0.05) between treatments was observed for the number of cows exhibiting small, medium, or dominant follicles, or estrus behavior. The number of cows which re-established ovarian cyclicity (n = 6) was lower (P < 0.05) in the SS than in the CS (n = 9). Corpus luteum lifespan was longer (P < 0.05) in the SS than in the CS. Intake of Leucaena affected the number of cows exhibiting ovarian cyclicity and extended corpus luteum life, but did not affect follicular development and estrus behavior.

  2. Kandungan Xantofil Daun Lamtoro (Leucaena leucocephala Hasil Detoksikasi Mimosin Secara Fisik dan Kimia

    Directory of Open Access Journals (Sweden)

    E. B. Laconi

    2010-04-01

    Full Text Available Leucaena (Leucena leucocephala is a feed source which has high protein and carotenoid, but its utilization as feed was limited by the presence of mimosine (β-N-(3-Hydroxy-4 pyridone-α amino propenoic acid as a toxin. Experiment was carried out using completely randomized design with 4 detoxification treatments and 5 replications. Detoxification treatments of leucaena leaf consisted of (1 non treated leucaena leaf, (2 steamed heating at 70 oC for 15 minutes, (3 dry heating at 70 oC for 12 h, (4 soaking with fresh water for 12 h, (5 spray with NaOH 5%, incubated for 12 h. Variables measured were mimosine and xanthophylls contents. Data were analyzed using analysis of variance and duncan multiple range test was further done to test the significant differences between means. The results showed that soaking leucaena leaf with fresh water for 12 h gave the highest reduction for both mimosine and xanthophylls contents and steamed heating at 70oC for 15 minutes had the highest xanthophylls content post detoxification. It was concluded that steamed heating at 70oC for 15 minutes was the best detoxification methods for mimosine in leucaena leaf.

  3. Efecto de la altura de poda en Leucaena leucocephala y su influencia en el rebrote y rendimiento de Panicum maximum

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    H. M. Bacab

    2012-01-01

    Full Text Available Una de las prácticas importantes de manejo en los sistemas de Leucaena leucocephala asociada con pastos tropicales, como Panicum maximum, es la poda; en la actualidad se continúan los estudios para determinar los efectos de esta práctica en el componente arbóreo y herbáceo. Por todo ello, en el presente trabajo se evaluó el efecto de tres alturas de poda en Leucaena leucocephala cv. Cunningham y su influencia en la pastura asociada (Panicum maximum cv. Tanzania. El estudio se realizó en la época poco lluviosa del año (marzo a mayo de 2010, se utilizó un diseño de bloques completos al azar con cuatro repeticiones. Al inicio del experimento se asignaron los tratamientos (alturas de poda de 20, 40 y 60 cm sobre el nivel del suelo para Leucaena leucocephala. En el caso de Panicum maximum, se realizó una poda a 5 cm sobre el nivel del suelo en todas las parcelas experimentales. Los resultados obtenidos indicaron que la poda de la leguminosa a 40 y 60 cm permitió obtener brotes de mayor talla, sin afectar a la gramínea asociada. De igual manera, al incrementar la altura de poda, la leguminosa presentó mayor rendimiento y proporción de forraje comestible; sin embargo, se afectó negativamente a la pastura asociada. Ante ello, considerándose el aspecto animal, se recomienda no reducir la altura de poda de Leucaena leucocephala a menos de 40 cm, ya que se reduce significativamente el rendimiento y la proporción de forraje comestible de esta leguminosa, el cual es de mayor calidad para la alimentación animal.

  4. Caracterización de la comunidad vegetal en una asociación de gramíneas mejoradas y Leucaena leucocephala cv.: Cunningham Characterization of the plant community in an association of improved grasses and Leucaena leucocephala cv.: Cunningham

    Directory of Open Access Journals (Sweden)

    Tania Sánchez

    2007-11-01

    Full Text Available En una vaquería de la Empresa Genética de Matanzas se realizó un estudio durante cinco años, con el objetivo de caracterizar el comportamiento de la comunidad vegetal en una asociación de gramíneas mejoradas y Leucaena leucocephala cv. Cunningham en condiciones comerciales. Se determinó la composición botánica del pastizal, la densidad de arbóreas, la disponibilidad de materia seca y los contenidos de MS, PB, Ca y P de las especies presentes en el sistema. La composición botánica del pastizal se caracterizó por un porcentaje de pastos mejorados superior al 50%, con predominio de Cynodon nlemfuensis cv. Jamaicano y Panicum maximum cv. Likoni; mientras que la leucaena mantuvo la densidad de plantas, como una adaptación a las condiciones del sistema. La disponibilidad de materia seca total fue superior a las 3 t/ha/rotación durante la etapa experimental. Se concluye que en la asociación de gramíneas mejoradas y L. leucocephala cv. Cunningham se presentó una alta disponibilidad de materia seca y persistencia del pastizal durante los cinco años del estudio, con valores de PB en las gramíneas mejoradas de 9,6-9,8% y en la leucaena de 25%, sin la aplicación de riego ni fertilizantes químicos, lo cual permitió atenuar las diferencias entre los períodos lluvioso y poco lluvioso.In a dairy of the Genetic Enterprise of Matanzas, a work was carried out for five years, with the objective of characterizing the performance of the plant community in an association of improved grasses and Leucaena leucocephala cv Cunningham under commercial conditions. The botanical composition of the pastureland, tree density, dry matter availability and DM, CP, Ca and P contents of the species present in the system were determined. The botanical composition of the pastureland was characterized by a percentage of improved pastures higher than 50%, with predominance of Cynodon nlemfuensis cv. Jamaicano and Panicum maximum cv. Likoni; while leucaena

  5. Systemic effects of Leucaena leucocephala ingestion on ringtailed lemurs (Lemur catta) at Berenty Reserve, Madagascar.

    Science.gov (United States)

    Crawford, Graham; Puschner, Birgit; Affolter, Verena; Stalis, Ilse; Davidson, Autumn; Baker, Tomas; Tahara, John; Jolly, Alison; Ostapak, Susan

    2015-06-01

    Leucaena (Leucaena leucocephala) is a leguminous tree that is nutritious forage for domestic livestock when ingested in limited amounts. Unfortunately, leucaena contains mimosine, a plant amino acid, that can be toxic when ingested at higher concentrations. Reported toxic effects include alopecia (fur loss), poor body condition, infertility, low birth weight, thyroid gland dysfunction, and organ toxicity. Originally native to Mexico and Central America, leucaena has been introduced throughout the tropics, including Berenty Reserve, Madagascar where it was planted as supplemental browse for livestock. In Berenty, a seasonal syndrome of alopecia in ringtailed lemurs (Lemur catta) is associated with eating leucaena. Although much is known about the toxic effects of leucaena and mimosine on domestic animals and humans, the systemic effects on wildlife had not been studied. In a comparison of lemurs that include leucaena in their diet and those that do not, we found that animals that ingest leucaena absorb mimosine but that ingestion does not affect body condition, cause kidney or liver toxicity, or affect the intestinal tract. Alopecia is due to mimosine's interference of the hair follicle cycle. Leucaena ingestion is associated with higher serum albumin, α-tocopherol, and thyroxine concentrations, suggesting that leucaena may provide some nutritional benefit and that lemurs can detoxify and convert mimosine to a thyroid stimulating metabolite. The primary conservation consequence of leucaena ingestion at Berenty may be increased infant mortality due to the infants' inability cling to their alopecic mothers. The widespread introduction of leucaena throughout the tropics and its rapid spread in secondary forest conditions mean that many other leaf-eating mammals may be including this tree in their diet. Thus, exposure to leucaena should be considered when wildlife health is being evaluated, and the potential effects on wildlife health should be considered when

  6. Acumulación de hojarasca en un pastizal de Panicum maximum y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala Litter accumulation in a Panicum maximum grassland and in a silvopastoral system of Panicum maximum and Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2007-09-01

    Full Text Available Se realizó un estudio en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", Matanzas, Cuba, con el objetivo de determinar la acumulación de la hojarasca en un pastizal de Panicum maximum Jacq cv. Likoni y en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham. En los pastizales de P. maximum de ambos sistemas se determinó la acumulación de la hojarasca según la técnica propuesta por Bruce y Ebershon (1982, mientras que la hojarasca de L. leucocephala acumulada en el sistema silvopastoril se determinó según Santa Regina et al. (1997. De forma general, los resultados demostraron que en ambos pastizales la guinea acumuló una menor cantidad de hojarasca durante el período junio-diciembre, etapa en la que se produce su mayor desarrollo vegetativo. En la leucaena la mayor producción de hojarasca ocurrió en el período de diciembre a enero, asociada con la caída natural de sus hojas que se produce por efecto de las temperaturas más bajas y la escasa humedad en el suelo. En el sistema silvopastoril la hojarasca de leucaena representó el mayor porcentaje de peso dentro de la producción total, con un contenido más alto de nitrógeno y de calcio que el de la hojarasca del estrato herbáceo. En la guinea la lluvia fue el factor climático que mayor correlación negativa presentó con la producción de hojarasca en ambos sistemas, y en la leucaena la mayor correlación negativa se encontró con la temperatura mínima.A study was carried out at the Experimental Station of Pastures and Forages "Indio Hatuey", Matanzas, Cuba, with the objective of determining the litter accumulation in a pastureland of Panicum maximum Jacq cv. Likoni and in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham. In the P. maximum pasturelands of both systems the litter accumulation was determined by means of the technique proposed by Bruce and Ebershon (1982, while

  7. IN VITRO FERMENTATION EFFICIENCY OF MIXTURES OF Cynodon nlemfuensis, Leucaena leucocephala AND TWO ENERGY SOURCES (MAIZE OR SUGAR CANE MOLASSES

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    Juan Martin Estrada-Liévano

    2009-07-01

    Full Text Available The in vitro fermentation efficiency of Cynodon nlemfuensis forage (star grass and Leucaena leucocephala foliage (leucaena and two energy sources (i.e. maize and sugar cane molasses mixture was evaluated. Mixture samples (1 g DM were incubated for 24 h. All the mixtures were added with 500 mg of polyetilenglycol (PEG. Adding molasses to star grass increased dry matter true digestibility and carbohydrate fermentation (P

  8. Características nutritivas del ensilaje de Leucaena leucocephala con diferentes aditivos

    OpenAIRE

    Betancourt de Flores, M.; Clavero, Tyrone; Razz, Rosa

    2009-01-01

    Para estudiar la influencia de la melaza y ácido fórmico sobre las características nutritivas del ensilaje de Leucaena leucocephala, se realizó un estudio en una zona caracterizada como Bosque muy seco tropical, estado Zulia, Venezuela. Tres niveles de melaza (0, 2.5 y 5%) y ácido fórmico (0, 0.25 y 0.5%) fueron evaluados, utilizándose un diseño experimental completamente aleatorizado con arreglo factorial 3x3. Se evaluaron los contenidos de materia seca total (MST), proteína cruda (PC)...

  9. Nutrient Dynamics and Litter Decomposition in Leucaena ...

    African Journals Online (AJOL)

    Nutrient contents and rate of litter decomposition were investigated in Leucaena leucocephala plantation in the University of Agriculture, Abeokuta, Ogun State, Nigeria. Litter bag technique was used to study the pattern and rate of litter decomposition and nutrient release of Leucaena leucocephala. Fifty grams of oven-dried ...

  10. Productive performance and urinary excretion of mimosine metabolites by hair sheep grazing in a silvopastoral system with high densities of Leucaena leucocephala.

    Science.gov (United States)

    Barros-Rodríguez, Marcos; Solorio-Sánchez, Javier; Ku-Vera, Juan; Ayala-Burgos, Armín; Sandoval-Castro, Carlos; Solís-Pérez, Georgina

    2012-12-01

    The aim of this study was to evaluate daily weight gain (DWG), total dry matter (DM) intake, rumen degradability of forage, and urinary excretion of mimosine metabolites by hair sheep in a silvopastoral system with high densities of Leucaena leucocephala. A completely randomized design was carried out with two treatments: treatment 1 (T1) silvopastoral system with leucaena at a density of 35,000 plants/ha and treatment 2 (T2), leucaena at a density of 55,000 plants/ha. Leucaena was associated with tropical grasses Panicum maximum and Cynodon nlemfluensis. Twenty-four male Pelibuey lambs of 23.2 ± 3.4 kg live weight (LW) were used (12 lambs per treatment). Results showed differences (P < 0.05) in DWG of T1 (106.41 ± 11.66 g(-1) sheep(-1)) with respect to that of T2 (81.33 ± 11.81 g(-1) sheep). Voluntary intake was higher in lambs from T1 (83.81 ± 04.07 g DM/kg LW(0.75)) with respect to that from T2 (71.67 ± 8.12 g DM/kg LW(0.75)). There was a difference in color of urine between sheep of T1 and T2, the latter giving positive results for the presence of metabolites derived from mimosine (3-4 dihydroxypyridine and 2-3 dihydroxy pyridone). Rumen degradability of DM of L. leucocephala was higher (P < 0.05) compared to that of P. maximum and C. nlemfluensis (72.94 ± 0.40 vs. 67.06 ± 1.50 and 63.25 ± 1.51 %, respectively). It is concluded that grazing at high densities of L. leucocephala affects daily weight gain of hair sheep, possibly due to ingestion of high amounts of mimosine which may exert an adverse effect on voluntary intake.

  11. Efecto del agua caliente en la germinación de las semillas de Leucaena leucocephala cv. Perú Effect of hot water on the germination of seeds from Leucaena leucocephala cv. Peru

    Directory of Open Access Journals (Sweden)

    Yolanda González

    2008-03-01

    Full Text Available En un diseño de clasificación simple se estudió el efecto del tratamiento pregerminativo con agua a 80ºC por dos minutos, en la germinación de las semillas de Leucaena leucocephala cv. Perú almacenadas al frío y al ambiente, durante siete años. Se demostró la presencia de dormancia moderada, con un porcentaje de germinación de 67,3% en la semilla recién cosechada, que fue inferior a la potencialidad germinativa mostrada a través de su alta viabilidad (98,2%. En condiciones controladas y al ambiente la germinación presentó diferencias altamente significativas para los meses de almacenamiento (PIn a simple classification design the effect of the pregerminative treatment with water at 80ºC for two minutes, on the germination of seeds from Leucaena leucocephala cv. Peru stored under cold-storage room and ambient conditions, for seven years, was studied. The presence of moderate dormancy was proven, with a germination percentage of 67,3% in the newly harvested seed, which was lower than the germination potential shown through their high viability (98,2%. Under controlled and ambient conditions germination showed highly significant differences for the storage months (P<0,001 and the highest values without applying pregerminative treatment were achieved at 12, 42 and 48 months (77,6; 71,8 and 75,7% and at 18 months (81,8%, respectively. The application of water at 80ºC for two minutes produced significant increases (P<0,001 in germination with regards to the untreated seed and under controlled conditions it was higher at 12, 24 and 48 months (98,6; 99,6 and 98,5% and under ambient conditions at 6, 12 and 18 months (96,2; 97,7 and 97,7%. It is concluded that the newly harvested seeds from L. leucocephala cv. Peru show around 30% dormancy and can increase their germination by applying water to them at 80ºC for two minutes.

  12. Crotalaria incana l. and leucaena leucocephala lam. (leguminosae): toxicity indicator species of petroleum hydrocarbons in soil; Crotalaria incana l. y leucaena leucocephala lam. (leguminosae): especies indicadoras de toxicidad por hidrocarburos de petroleo en el suelo

    Energy Technology Data Exchange (ETDEWEB)

    Vazquez Luna, Dinora; Castellan Estrada, Mepivoseth; Rivera Cruz, Maria del C.; Ortiz Ceballos, Angel I.; Izquierdo R., Francisco [Colegio de Postgraduados, Campus Montecillo, Montecillo, Estado de Mexico (Mexico)]. E-mail: dinovaz@colpos.mx

    2010-07-01

    This study assesses the toxic effects produced by a Gleysol molic soil contaminated with crude oil on seedlings of two species of legumes. A phytotoxic impact index (IIF) was generated, which includes five parameters measured by relative rates of impact (IRIF{sub (x)}) for variables; emergency, height, root length, aboveground biomass and root biomass. Bioassays were conducted under a completely randomized design with three replications under semi-controlled conditions, to assess the sensitivity of Leucaena leucocephala and Crotalaria incana at different concentrations of TPH (total petroleum hydrocarbons). Effects were highly significant (P {<=} 0.01) with increasing concentrations of HTP in substrate. The emergence of L. leucocephala was 29 % lower with 80 000 mgkg{sup -1} HTP, while C. incana decreased 30 % with 32 000 mgkg{sup -1} TPH respect to control. Both species showed a five-day delay in the emergence of seedlings when exposed to high levels of TPH. A significant decrease in the accumulation of dry matter (DM) at concentrations above 20 000 mgkg{sup -1} TPH was observed in both species. The respective IIF declined of 50 % with 80 000 and 25 000 mgkg{sup -1} TPH, but L. leucocephala had no significant effect with 10 000 mgkg{sup -1} TPH. Finally, the EC50 in L. leucocephala, is presented with 80 000 mgkg{sup -1} TPH whereas in C. incana this parameter is noted from 25 000 mgkg{sup -1} TPH. [Spanish] En este estudio se evaluaron los efectos toxicos que produce un suelo Gleysol molico contaminado con petroleo crudo, sobre plantulas de dos especies de leguminosas. Para ello se genero un indice de impacto fitotoxico (IIF) que integra cinco parametros, medidos a traves de indices relativos de impacto (IRIF{sub (x)}) para las variables emergencia, altura, longitud radicular, biomasa aerea y biomasa radicular. Los bioensayos se realizaron bajo un diseno completamente al azar, con tres repeticiones, en condiciones semicontroladas, para evaluar la sensibilidad de

  13. Leucaena leucocephala (Lam. de Wit (Fabaceae: invasora ou ruderal? Leucaena leucocephala (Lam. de Wit (Fabaceae: invasive or ruderal?

    Directory of Open Access Journals (Sweden)

    José Nicola Martorano Neves da Costa

    2010-10-01

    Full Text Available A utilização de espécies exóticas em plantios de recuperação de áreas degradadas tem sido condenada com base no argumento de que tais espécies podem se comportar como invasoras e contaminar os ecossistemas naturais ao redor das áreas onde forem plantadas. Leucaena leucocephala (leucena é espécie leguminosa exótica que tem sido frequentemente cultivada no Brasil para recuperação florestal, uma vez que apresenta simbiose com bactérias fixadoras de nitrogênio, melhorando a fertilidade dos solos. O potencial de invasão e persistência da leucena foi analisado a partir de um plantio misto, efetuado em 1983 em terreno com afloramento rochoso, parte do mosaico de uma paisagem dominada por matriz agrícola, com alguns fragmentos remanescentes de floresta estacional semidecidual e plantios arbóreos diversos. Em uma área de 200 ha, cada uma das 11 unidades do mosaico foi amostrada por meio de seis parcelas de 16 x 3 m (48 m², em que foram identificados e medidos (DAP todos os indivíduos de espécies arbóreas (altura mínima de 50 cm, para verificar se a área ocupada pela espécie está se expandindo. Na área em que foi utilizada leucena no plantio, analisou-se a estrutura da comunidade, com base na distribuição dos indivíduos em classes de tamanho, para verificar se a proporção da espécie exótica tende a aumentar com o tempo, configurando a persistência no ecossistema. Uma vez que nenhum indivíduo de L. leucocephala foi registrado entre os 4.599 amostrados além dos limites da área onde a espécie foi plantada, a conclusão é de que a espécie não está se comportando como invasora de ecossistemas naturais nessa condição ambiental, enquadrando-se melhor como ruderal. A análise da comunidade em regeneração sob as árvores plantadas evidenciou que a proporção da espécie exótica, que é intolerante à sombra, tende a diminuir com o tempo, ainda que lentamente, perdendo espaço para espécies nativas tolerantes

  14. Poblaciones microbianas ruminales en novillas alimentadas con Leucaena leucocephala en el Bosque Seco Tropical colombiano.

    Directory of Open Access Journals (Sweden)

    Erika Angarita

    2015-05-01

    Full Text Available La fermentación y metanogénesis ruminal son procesos metabolicos vitales para los bovinos y son llevados a cabo por poblaciones microbianas, las cuales se afectan por factores como la presencia de metabolitos secundarios, la composición nutricional y la degradabilidad de la dieta. El objetivo de este trabajo fue monitorear las poblaciones de bacterias totales, metanógenos totales y Butirivibrio fibrisolvens en el rumen de novillas raza Lucerna, alimentadas con dietas típicas de un sistema silvopastoril intensivo y un sistema tradicional. Para ello, se colectó contenido ruminal (CR por vía oral a ocho novillas que consumían 100% Cynodon plectostachyus (control y 76% C. plectostachyus + 24% Leucaena leucocephala siguiendo un diseño de sobre-cambio. A partir del CR se extrajo y cuantificó ADN mediante PCR cuantitativa. Las poblaciones [Log10 (ng/g CR] fueron 5.6 y 5.8 para bacterias totales (P= 0.5343, 3.6 y 3.5 para B. fibrisolvens (P= 0.4742, y 5.0 y 5.3 para metanógenos totales (P= 0.2661, para la dieta control y la dieta con leucaena respectivamente. Las poblaciones monitoreadas cuantitativamente no difirieron de manera significativa con la inclusión de L. leucocephala. Esto indica la importancia de investigar la estructura, función e interacciones de las poblaciones más allá del análisis cuantitativo para determinar cómo la dieta afecta las poblaciones microbianas ruminales y su función.

  15. Chemical elements in Leucaena leucocephala leaves of riparian zones of the municipality of Piracicaba, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J. de; Fernandes, Elisabete A.N.; Lira, Marcelo G.; Ferreira, Fabiano S.; Cavalca, Isabel P.O.; Rodrigues, Vanessa S.; Camilli, Leandro

    2017-01-01

    The species Leucaena leucocephala can be found in several riparian ecosystems, acting as one of the main invasive and harmful species for the forest restoration of the permanent preservation areas. It has also been studied for the phytoremediation of some chemical elements, due to their potential accumulation of chemical substances. Therefore, the present study aimed to evaluate the accumulation of chemical elements in leaves of Leucaena leucocephala trees by Instrumental Neutronic Activation Analysis - INAA. Samples of leaves were collected in eight samples from riverside areas of the Piracicaba Municipality, São Paulo, Brazil, during the dry and rainy season. After collection, washing with water and drying in a forced circulation oven, the samples were comminuted and encapsulated in polyethylene capsules and subjected to a thermal neutron flux of 10 13 cm -2 s -1 for 8 hours in the Nuclear Research Reactor IEA-R1 of IPEN / CNEN. Thermal neutron flux monitoring was performed by Ni-Cr alloy fragments with known concentrations of the chemical monitors elements. After measurements of radioactivity induced by HPGe detectors, the concentrations of the chemical elements were calculated by the k0 method using the Quantu computer program. Certified reference materials were also analyzed for quality assurance of the analytical procedure. The results indicated high concentrations of La and lanthanoids (Ce, Eu, Sm, Tb and Yb) in leaves of L. leucocephala in both periods analyzed. It was possible to observe a decrease in the concentrations of the chemical elements in the rainy season, probably associated to the washing of the geological material deposited on the leaves of the trees by the rains, except for K, Mo, Rb, Sb and Zn, whose values remained or increased in the leaves collected during the rainy season. Considering the constant leaf production, L. leucocephala can greatly affect the cycling of chemical elements due to its accumulation capacity demonstrated by this

  16. Chemical elements in Leucaena leucocephala leaves of riparian zones of the municipality of Piracicaba, São Paulo, Brazil; Elementos químicos em folhas de Leucaena leucocephala de zonas ripárias do município de Piracicaba, São Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J. de; Fernandes, Elisabete A.N.; Lira, Marcelo G.; Ferreira, Fabiano S.; Cavalca, Isabel P.O.; Rodrigues, Vanessa S.; Camilli, Leandro, E-mail: ejfranca@yahoo.com.br, E-mail: liramarcelo@hotmail.com, E-mail: biologofabiano10@gmail.com [Centro Regional de Ciências Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2017-07-01

    The species Leucaena leucocephala can be found in several riparian ecosystems, acting as one of the main invasive and harmful species for the forest restoration of the permanent preservation areas. It has also been studied for the phytoremediation of some chemical elements, due to their potential accumulation of chemical substances. Therefore, the present study aimed to evaluate the accumulation of chemical elements in leaves of Leucaena leucocephala trees by Instrumental Neutronic Activation Analysis - INAA. Samples of leaves were collected in eight samples from riverside areas of the Piracicaba Municipality, São Paulo, Brazil, during the dry and rainy season. After collection, washing with water and drying in a forced circulation oven, the samples were comminuted and encapsulated in polyethylene capsules and subjected to a thermal neutron flux of 10{sup 13} cm{sup -2}s{sup -1} for 8 hours in the Nuclear Research Reactor IEA-R1 of IPEN / CNEN. Thermal neutron flux monitoring was performed by Ni-Cr alloy fragments with known concentrations of the chemical monitors elements. After measurements of radioactivity induced by HPGe detectors, the concentrations of the chemical elements were calculated by the k0 method using the Quantu computer program. Certified reference materials were also analyzed for quality assurance of the analytical procedure. The results indicated high concentrations of La and lanthanoids (Ce, Eu, Sm, Tb and Yb) in leaves of L. leucocephala in both periods analyzed. It was possible to observe a decrease in the concentrations of the chemical elements in the rainy season, probably associated to the washing of the geological material deposited on the leaves of the trees by the rains, except for K, Mo, Rb, Sb and Zn, whose values remained or increased in the leaves collected during the rainy season. Considering the constant leaf production, L. leucocephala can greatly affect the cycling of chemical elements due to its accumulation capacity

  17. Characterization analysis for leaves of Leucaena leucocephala by using phytochemical screening assay

    Science.gov (United States)

    Zarina, Z.; Ghazali, C. M. R.; Sam, S. T.

    2017-09-01

    Leucaena Leucocephala (Lam.) de Wit (Petai Belalang) is a medium plant which belong in group of tropical breed that can survived in hot, dried and warm environment. In Malaysia, the plant is available abundantly. As there are still no commercial used, and no serious intention in finding the benefits of L. Leucocephala, this work come out with the idea to analyze the antioxidants contains in leaves of the plant by undergoes different extraction and chemical testing method. The phytochemical screening assay involved in this study are antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, total phenolic content by using Folin-Ciocalteu method, total flavonoid content by using colorimetric assay with ascorbic acid and quercetin were used as reference standards while for phosphorus analysis, a molybdenum blue method or also known as ascorbic acid method was used. For antioxidant activity by using free radical diphenylpicrylhydrazyl (DPPH) method, higher concentration was recorded by extraction using methanol (dried sample) which is 8247.0 mg/L, for total phenolic content higher concentration was recorded by extraction using deionized water (dried sample) which is 4276.0 mg/L, for total flavonoid content by using colorimetric assay higher concentration was recorded by extraction using methanol (dried sample) which is 4439.0 mg/L, and for for phosphorus analysis higher concentration was recorded by extraction using methanol (dried sample) which is 71.057 mg/L.

  18. La productividad de cabras ramoneando Leucaena leucocephala en las áreas semi áridas del noroeste de Venezuela

    OpenAIRE

    Clavero, Tyrone; Razz, Rosa

    2009-01-01

    Un experimento de campo fue realizado en las áreas semiáridas del noroeste de Venezuela para evaluar tres tipos de dietas en cabras (pastoreo de gramíneas (pasto buffel); pastoreo de gramíneas + 0.3 kg/día de alimento comercial); pastoreo de gramíneas + ramoneo restrictivo de dos horas diarias en Leucaena leucocephala) sobre la producción y composición de la leche y la tasa de crecimiento. Los datos muestran diferencias significativas (P

  19. Expression analysis of cinnamoyl-CoA reductase (CCR) gene in developing seedlings of Leucaena leucocephala: a pulp yielding tree species.

    Science.gov (United States)

    Srivastava, Sameer; Gupta, Ranadheer K; Arha, Manish; Vishwakarma, Rishi K; Rawal, Shuban K; Kavi Kishor, P B; Khan, Bashir M

    2011-02-01

    Removal of lignin is a major hurdle for obtaining good quality pulp. Leucaena leucocephala (subabul) is extensively used in paper industry in India; therefore, as a first step to generate transgenic plants with low lignin content, cDNA and genomic clones of CCR gene were isolated and characterized. The cDNA encoding CCR (EC 1.2.1.44) was designated as Ll-CCR; the sequence analysis revealed an Open Reading Frame (ORF) of 1005 bp. Phylogenetic analysis showed that Ll-CCR sequence is highly homologous to CCRs from other dicot plants. The 2992 bp genomic clone of Leucaena CCR consists of 5 exons and 4 introns. The haploid genome of L. leucocephala contains two copies as revealed by DNA blot hybridization. Ll-CCR gene was over-expressed in Escherichia coli, which showed a molecular mass of approximately 38 kDa. Protein blot analysis revealed that Ll-CCR protein is expressed at higher levels in root and in stem, but undetectable in leaf tissues. Expression of CCR gene in Leucaena increased up to 15 d in case of roots and stem as revealed by QRT-PCR studies in 0-15 d old seedlings. ELISA based studies of extractable CCR protein corroborated with QRT-PCR data. CCR protein was immuno-cytolocalized around xylem tissue. Lignin estimation and expression studies of 5, 10 and 15 d old stem and root suggest that CCR expression correlates with quantity of lignin produced, which makes it a good target for antisense down regulation for producing designer species for paper industry. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  20. Studies on the variations in the chemical composition of leucaena ...

    African Journals Online (AJOL)

    The fermentation quality and nutritive value of leucaena ensiled either as whole forage or separate stem and leaf fractions were investigated. About 10-month-old leucaena (Leucaena leucocephala (Lam.) De Wit.) grown in Okinawa Island, Japan, was used.Samples were chopped to about 4 cm lengths and stuffed into ...

  1. Características Dendrométricas, Físicas e Químicas da Myracrodruon urundeuva e da Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    Lázaro Lavoisier Honorato da Silva

    2017-04-01

    Full Text Available RESUMO Com o objetivo de avaliar características dendrométricas, físicas e químicas da Myracrodruon urundeuva e Leucaena leucocephala foi realizada supressão de cinco exemplares de cada espécie. Os parâmetros dendrométricos avaliados foram: DAP, altura, volume. Avaliou-se a densidade básica e foram feitas análises químicas da madeira. O experimento foi arranjado em delineamento inteiramente casualizado (DIC, com valores analisados pelo teste F ao nível de 5%. As espécies M. urundeuva e L. leucocephala apresentaram, respectivamente, média de DAP 10,00 cm; 14,08 cm; altura total 8,20 m; 12,93 m; altura comercial 4,90 m; 10,07 m; volume com casca (C/C 0,032 m3; 0,104 m3; volume sem casca (S/C 0,025 m3; 0,095 m3. M. urundeuva apresentou maior densidade básica. O teor de cinzas encontrado para M. urundeuva foi superior. Já os teores de extrativos totais e holocelulose da M. urundeuva e da L. leucocephala foram semelhantes. A L. leucocephala obteve maior teor de lignina total e poder calorífico superior. Portanto, as duas espécies apresentaram boas características físicas, químicas e energéticas.

  2. The first assessment of the stress inducible defense of Leucaena leucocephala with acaricidal potential effect against Rhipicephalus (Boophilus microplus (Acari: Ixodidae

    Directory of Open Access Journals (Sweden)

    Lêdia Feitosa Wanderley

    Full Text Available Abstract Plants respond to wounding caused by mechanical stress or herbivory by synthesizing defense proteins. There are no studies reporting the action of induced plant proteins against ticks. The aim of this study was to investigate the effect of mechanically wounded Leucaena leucocephala leaves against Rhipicephalus (Boophilus microplus. Initially, we carried out time course experiments to evaluate the impact of mechanical wounding on the protein content and the peroxidase, catalase and protease inhibitor activities in L. leucocephala. We then evaluated the acaricidal activity on R. (B. microplus from protein extract collected from L. leucocephala after mechanical wounding. L. leucocephala leaves were artificially wounded, and after 6, 12, 24 and 48h, the leaves were collected for protein extraction. Quantitative and qualitative analyses of the proteins were performed. The protein content and peroxidase and protease activities increased 12h after wounding, and the acaricidal activity of this protein extract was evaluated using engorged R. (B. microplus females. The protein extract obtained after wounding reduced egg production (8.5% compared to those without wounding. Furthermore, the extract reduced egg hatching by 47.7% and showed an overall efficacy of 56.3% at 0.1 mgP/mL of the protein. We demonstrated that L. leucocephala defensive proteins could be effective against R. (B. microplus.

  3. Soil Solution Phosphorus Status and Mycorrhizal Dependency in Leucaena leucocephala†

    Science.gov (United States)

    Habte, Mitiku; Manjunath, Aswathanarayan

    1987-01-01

    A phosphorus sorption isotherm was used to establish concentrations of P in a soil solution ranging from 0.002 to 0.807 μg/ml. The influence of P concentration on the symbiotic interaction between the tropical tree legume Leucaena leucocephala and the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum was evaluated in pot experiments. The level of mycorrhizal infection in Leucaena roots increased as the concentration of P was raised from 0.002 to 0.153 μg/ml. Higher levels of P depressed mycorrhizal infection, but the level of infection never declined below 50%. Periodic monitoring of P contents of Leucaena subleaflets indicated that significant mycorrhizal activity was detected as early as 17 days after planting, with the activity peaking 12 to 16 days thereafter. The highest level of mycorrhizal activity was associated with a soil solution P level of 0.021 μg/ml. Even though the mycorrhizal inoculation effect diminished as the concentration of P in the soil solution was increased, mycorrhizal inoculation significantly increased P uptake and dry-matter yield of Leucaena at all levels of soil solution P examined. The concentration of P required by nonmycorrhizal L. leucocephala for maximum yield was 27 to 38 times higher than that required by mycorrhizal L. leucocephala. The results illustrate the very high dependence of L. leucocephala on VAM fungi and the significance of optimizing soil solution phosphorus for enhancing the benefits of the VAM symbiosis. PMID:16347323

  4. Anatomy and ultrastructure alterations of Leucaena leucocephala (Lam.) inoculated with mycorrhizal fungi in response to arsenic-contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Jerusa, E-mail: jerusaschneider@hotmail.com [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Labory, Claudia Regina Gontijo [Departamento de Fitopatologia, Universidade Federal de Lavras, PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Rangel, Wesley Melo [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Alves, Eduardo [Departamento de Fitopatologia, Universidade Federal de Lavras, PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil); Guilherme, Luiz Roberto Guimarães [Departamento de Ciência do Solo, Universidade Federal de Lavras (UFLA), PO Box 3037, Lavras, Minas Gerais, 37200-000 (Brazil)

    2013-11-15

    Highlights: ► Inoculation of L. leucocephala improved plant growth in high-As soils. ► Plants inoculated with Glomus clarum were less sensitive to As. ► Ultrastructural changes in leaves of L. leucocephala. ► Modified structures in intracellular spaces in plants inoculated with G. clarum. ► Cell disruption and stacking of root cell walls at high As concentrations. -- Abstract: Many studies demonstrate the potential application of arbuscular mycorrhizal fungi (AMF) for remediation purposes, but little is known on AMF potential to enhance plant tolerance to arsenic (As) and the mechanisms involved in this process. We carried anatomical and ultrastructural studies to examine this symbiotic association and the characteristics of shoots and roots of Leucaena leucocephala in As-amended soils (35 and 75 mg As dm{sup −3}). The experiment used 3 AMF isolates from uncontaminated soils: Acaulospora morrowiae, Glomus clarum, and Gigaspora albida; a mixed inoculum derived from combining these 3 isolates (named Mix AMF); and, 3 AMF isolates from As-contaminated areas: A. morrowiae, G. clarum and Paraglomus occultum. Phytotoxicity symptoms due to arsenic contamination appeared during plant growth, especially in treatments without AMF application. Inoculation with G. clarum and the mixture of species (A. morrowiae, G. albida, and G. clarum) resulted in better growth of L. leucocephala in soils with high As concentrations, as well as significant As removal from the soil, showing a potential for using AMF in phytoextraction. Light microscopy (LS), transmission (TEM) and scanning electron microscopies (SEM) studies showed the colonization of the AMF in plant tissues and damage in all treatments, with ultrastructural changes being observed in leaves and roots of L. leucocephala, especially with the addition of 75 mg dm{sup −3} of As.

  5. Considerations about Leucaena leucocephala cv. X: A new forage choice for a livestock ecosystem with acid and infertile soils

    OpenAIRE

    Pérez, A; Wencomo, Hilda; Navarro, Marlen; Iglesias, J.M; Soca, Mildrey; Cepero, L; Canchila, E.R

    2008-01-01

    El presente estudio se realizó a partir de una búsqueda de información por diversas páginas Web, revistas de impacto, otras de carácter nacional e internacional, así como las más diversas fuentes de información, relacionada con la capacidad de adaptación del género Leucaena a los diferentes tipos de suelo, con énfasis en la acidez y el grado de encharcamiento. La revisión proporcionó las limitantes de adaptación del género y de la especie L. leucocephala a dichas condiciones. El descubrimient...

  6. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: I. Influencia de su composición química Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: I. Influence of their chemical composition

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2009-09-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca y su relación con la composición química de Panicum maximum y Leucaena leucocephala en un sistema silvopastoril, se realizó este experimento en la EEPF "Indio Hatuey". La descomposición de la hojarasca se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags. En cada especie se presentó un patrón diferente de descomposición de la hojarasca; la tasa promedio de descomposición de la hojarasca en leucaena fue mayor que en la guinea. En ambas especies se encontró una rápida pérdida de peso durante los primeros 30 días y después el proceso fue más lento. Este comportamiento puede estar relacionado con la composición química de los pastos, pues el porcentaje de biomasa perdida de la hojarasca de L. leucocephala presentó una mayor correlación con las concentraciones del contenido celular, la relación lignina/nitrógeno, la celulosa y el Nt. Se observó una dependencia significativa y negativa de la hojarasca de P. maximum con las concentraciones de la FND y la hemicelulosa; mientras que se relacionó de forma positiva con las de N-FND y la relación lignina/nitrógenoWith the objective of determining the litter decomposition and its relationship to the chemical composition of Panicum maximum and Leucaena leucocephala in a silvopastoral system, this trial was conducted at the EEPF «Indio Hatuey». Litter decomposition was determined as biomass loss through time, with regards to initial weight. For studying the decomposition dynamics, the method of litter bags was used. In each species a different litter decomposition pattern appeared; the average litter decomposition rate was higher in leucaena than in Guinea grass. Rapid weight loss was found in both species during the first 30 days and afterwards the process was slower

  7. Effect of feed restriction on intake of Moringa oleifera and Leucaena leucocephala and growth performance of rabbits.

    Science.gov (United States)

    Santos-Ricalde, R; Gutiérrez-Ruiz, E; Novelo-Ucan, W; Martinez-Romero, P; Segura-Correa, J

    2017-12-01

    Two experiments were conducted to evaluate the effect of feed restriction on intake of Moringa oleifera (MO) or Leucaena leucocephala (LL) and growth of rabbits. In experiment one, 45 rabbits (male and female) weighing 1.18 ± 0.15 kg were used. They were randomly distributed to three feed restriction treatments (20, 30, and 40%) with 15 rabbits each (9 females and 6 males) and they were offered M. oleifera (MO) ad libitum. In experiment two, 45 growing male rabbits weighing 0.63 ± 0.113 kg were used. They were randomly assigned to 0, 20, and 30% feed restriction diets, and they have free access to L. leucocephala (LL). Intake of MO increased (P  0.05), and economic efficiency was similar among treatments. Consumption of LL increased (P  0.05). Economic efficiency improved twice in feed-restricted rabbits (2.0 and 2.3 for 20 and 30%, respectively) in contrast to that of the control 0% group (1.1). The results suggest that rabbits restricted up to 30% and supplemented with either MO or LL did not affect growth performance and reduced feed cost.

  8. Milk yield and blood urea nitrogen in crossbred cows grazing Leucaena leucocephala in a silvopastoral system in the Mexican tropics

    Directory of Open Access Journals (Sweden)

    Maria B. Bottini-Luzardo

    2016-09-01

    Full Text Available The aim of the study was to assess milk yields, estimate the intake of crude protein (CP and determine the concentrations of blood urea nitrogen (BUN in early post-partum crossbred cows grazing irrigated Leucaena leucocephala (leucaena in a silvopastoral system relative to those in an irrigated grass monoculture.  Twenty-four multiparous cows were randomly allotted at calving on the basis of previous milk yields to 2 grazing treatments: grass monoculture system (MS of Cynodon nlemfuensis (n=12; and an intensive silvopastoral system (ISS composed of leucaena and C. nlemfuensis (n=12.  Cows were supplemented with sorghum grain (ISS or a conventional concentrate (MS during milking to ensure availability of metabolizable energy (ME and CP required for milk production.  Mean estimated intake of leucaena was 5.1±1.3 kg DM/d and estimated CP intakes were 1,479±3.3 and 1,258±3.3 g/d for ISS and MS, respectively (P>0.05, while estimated intakes of ME were 161±1.3 and 131±1.4 MJ/d for ISS and MS, respectively (P<0.05.  Milk yields were 13.5 and 14.5 kg/cow/d for cows on ISS and MS, respectively (P>0.05.  Concentrations of BUN were 19.1 mg/dL for cows in ISS and 15.3 mg/dL for cows in MS (P<0.05.  We conclude that intake of leucaena and sorghum grain in an irrigated silvopastoral system was sufficient to substitute for expensive concentrate in the diets of lactating cows grazing irrigated grass monoculture.  However, the higher levels of BUN found in ISS suggest a lower efficiency of N utilization in this treatment.  Restricting consumption of leucaena might be a means of improving efficiency of its use and this warrants investigation. Keywords: Cattle, crude protein, Cynodon nlemfuensis, leucaena, tropical pasturesDOI: 10.17138/TGFT(4159-167

  9. INFLUÊNCIA DE TRATAMENTOS PRÉ-GERMINATIVOS, TEMPERATURA E LUMINOSIDADE NA GERMINAÇÃO DE SEMENTES DE LEUCENA (Leucaena leucocephala (Lam. De Wit., cv. CUNNINGHAM

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    Alexandre Bosco de Oliveira

    2009-01-01

    Full Text Available The research was lead in two experiments with the objective of to identify methods to superation of dormancy in seeds of Leucaena leucocephala, Cunningham variety, and to verify the effect of light and temperatures in germination of this species. In first the seeds were submitted the nine methods to superation of dormancy: immersion in water under ambient temperature during 24, 48 and 72 hours, immersion in hot water under temperatures of 60, 80 and 100oC, immersion in sulfuric acid per 5 and 10 minutes, beyond of the witness. In second experiment, after treatment with sulfuric acid for 10 minutes, the seeds were sowed in tabledoch paper type Germitest and put to germinate under ten combinations: continue light and constant temperature of 20, 25, 30 and 35oC; dark continue and constant temperature of 20, 25, 30 and 35oC; alternated temperature of 20-30 and 25-35, both with fotoperiod of eight hours. Conclusion the specie Leucaena leucocephala presents seeds dormancy, detach-itself the sulfuric acid as efficient method to the superation of dormancy; the seeds of leucena are insensitive to the light and your germination was not influenced by the temperatures useds.

  10. Forage production and growing goats’ response under silvopastoral systems based on Guazuma ulmifolia, Leucaena leucocephala and Crescentia cujete

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    Gustavo Rodríguez Fernández

    2013-01-01

    Full Text Available Grass monoculture, besides being unnatural to goat’s natural eating habits, exhibits low forage production during the dry season, with negative impacts on animal productivity. This research aimed to determine the productive advantages of silvopastoral system arrangements in goat production. A completely randomized design with repeated measurements through time was used. Six treatments were evaluated: kikuyina grass monoculture (Bothriochloa pertusa and guinea grass monoculture (Panicum maximum cv. Tanzania as control groups; guacimo (Guazuma ulmifolia based silvopastoral arrangement; calabash (Crescentia cujete based silvopastoral arrangement; lead tree (Leucaena leucocephala based silvopastoral arrangement; and a mixed based silvopastoralarrangement (guacimo, calabash and leucaena. The information was processed with analysis of variance. The results showed increased forage production in silvopastoral arrangements vs. Bothriochloa pertusa monoculture. The greater increase in height (p <0.05 at 9-14 months of age, was obtained with the leucaena silvopastoral arrangement. All silvopastoral arrangements showed forage yield advantages compared to B. pertusa. The higher dry matter production of guinea grass is highlighted. Overall weight gain of the growing goats was low; nevertheless, a differential response between treatments was observed. Silvopastoral arrangements had the highest (p <0.05 weight gain (22.5 to 33.6 g/animal per day relative to the guinea grass monoculture (13.2 g/animal per day. The growing goats had higher percentages of estrus and pregnancy in the mixed system (66.7% and those based on guacimo (66.7% and on lead tree (55.6%.

  11. Fertigation by capillary action in seedlings of Leucaena leucocephala (Lam. de Wit = Fertirrigação por capilaridade em mudas de Leucaena leucocephala (Lam. de Wit.

    Directory of Open Access Journals (Sweden)

    Renata de Paiva Dantas

    2016-07-01

    Full Text Available The leucena (Leucaena leucocephala, native to Central America, produces large quantities of viable seeds, which allows its propagation on a large scale; it is also fast-growing and can reach 7 m in height. The use of fertigation favours the absorption of nutrients, and the greater growth of the leucena seedlings, due to the application of less concentrated nutrient solutions of a consequently lower electrical conductivity. However, this practice requires a lot of manpower, and it is necessary to find alternative technologies that would allow a reduction in the costs of fertigation. The aim of this study therefore was to evaluate the viability of fertigation by capillary action, using different concentrations of a standard nutrient solution in the production of seedlings of leucena. A completely randomised experimental design was used, with treatments comprising four concentrations of nutrient solution (0, 50, 100 and 150% applied by capillary fertigation. Two nondestructive evaluations of growth were carried out at 25 and 40 days after sowing (DAS, and one destructive evaluation at 55 DAS. The variables to be evaluated were: plant height, stem diameter, number of leaves and biomass accumulation, besides the quality indices of the seedlings. Analysis of the data leads to the conclusion that seedlings of leucena can be produced at concentrations of between 70 and 100% of the nutrient solution through fertigation by capillary action. = A leucena (Leucaena leucocephala, originária da América Central, produz grandes quantidades de sementes viáveis, o que permite sua propagação em larga escala, e possui crescimento rápido, podendo chegar a 7 metros de altura. O uso da fertirrigação favorece a absorção de nutrientes e o maior crescimento das mudas de leucena, devido à aplicação de solução nutritiva menos concentrada e, consequentemente, com menor condutividade elétrica. Nesse sentido, objetivou-se com este trabalho avaliar a viabilidade

  12. Etude comparée des performances pondérales des chèvres naines de Guinée supplémentées au Leucaena leucocephala, au Gliricidia sepium ou au tourteau de coton dans l'Ouest Cameroun

    Directory of Open Access Journals (Sweden)

    Tedonkeng Pamo, E.

    2001-01-01

    Full Text Available Comparative Growth Performance of West African Dwarf Goat Supplemented with Leucaena leucocephala, Gliricidia sepium or Cotton Seed Cake in West Cameroon. A comparative growth performance study of West African Dwarf Goat supplemented with Leucaena leucocephala, Gliricidia sepium or cotton seed cake was carried out on-farm around Dschang and at the University Experimental Farm on the Western Highland region of Cameroon. Goats aged between 12 and 16 months were divided into 4 groups of 11 animals each, with one group kept as a control. The goats in the supplemented groups received 390 g of L. leucocephala, 513 g of G. sepium and 88.8 g of cotton seed cake respectively, corresponding to a supplementation 6 g of nitrogen per animal per day. Animals were weighed every 21 days during an 84 days period to evaluate their response to supplementation. The weights of animals supplemented with cotton seed cake were not significantly (P> 0.05 different from those of animals supplemented with L. leucocephala. Similarly the weights of animals supplemented with G. sepium were not different from those of the controls. The adjusted average daily weight gains per goat were 18.9 g ; 17.3 g ; 4.3 g ; and 4.0 g respectively for animals supplemented with cotton seed cake, L. Leucocephala, G. sepium and of the control group.

  13. Descomposición del follaje de Leucaena leucocephala cv. Cunningham asociada con Morus alba var. tigríada

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    F Ruz Súarez

    Full Text Available El presente estudio se diseñó en una parcela experimental donde se utiliza, desde hace diez años, el follaje de Leucaena leucocephala (leucaena como abono verde en el cultivo de Morus alba (morera, con el objetivo de determinar la velocidad de descomposición del follaje de la leguminosa y la relación de este proceso con algunos de los factores bióticos y abióticos presentes en el sistema. Para el estudio de la dinámica de la descomposición del follaje se utilizó el método de bolsas de hojarasca (litter bags. El follaje depositado en estas bolsas fue evaluado en seis momentos durante la etapa de estudio, que abarcó dos años. En cada fecha de recolección, a la hojarasca remanente de cada bolsa se le determinó la población de macrofauna mediante la separación manual, según la metodología del Programa de Investigación Internacional "Biología y Fertilidad del Suelo Tropical" (TSBF. La composición taxonómica de la macrofauna asociada al proceso de descomposición del follaje de leucaena estuvo constituida por cuatro Phylum, seis clases y siete órdenes. El 97% de los organismos eran detritívoros y el 3% depredadores. El tipo de bolsa no influyó en la descomposición del follaje y los factores climáticos desempeñaron un rol decisivo en este proceso.

  14. CARACTERIZACIÓN DE DIEZ CULTIVARES FORRAJEROS DE Leucaena leucocephala BASADA EN LA COMPOSICIÓN QUÍMICA Y LA DEGRADABILIDAD RUMINAL

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    Danny García M

    2008-08-01

    Full Text Available Objetivo. Estudiar las variaciones en la composición química y la degradabilidad ruminal de diez cultivares de Leucaena leucocephala Lam. de Wit. mediante el análisis de componentes principales (ACP. Materiales y métodos. Se tomaron muestras durante tres años para evaluar la composición química, los niveles de metabolitos secundarios y la degradabilidad ruminal en ovinos. Los datos fueron analizados con el paquete estadístico SPSS y mediante el diagrama tridimensional se obtuvieron las agrupaciones de las accesiones en dependencia de sus características nutritivas. Resultados. Con los primeros tres componentes del ACP se explicó el 85.83 % de la variabilidad. La concentración de proteínas, fracción fibrosa, minerales, polifenoles, fitatos y la degradación ruminal presentaron las mayores fluctuaciones. Las agrupaciones formadas permitieron identificar seis grupos con características químicas diferentes (G1: elevada cantidad de proteínas, baja proporción de fibra y de metabolitos secundarios y elevada degradación -cv. CNIA-250 y cv. K-28-; G-2: elevado contenido de materia seca, proteínas y fenoles, poca fracción de fibra y taninos y baja degradabilidad ruminal -cv. Ipil-Ipil-; G-3: composición nutricional promedio -cv. México-; G-4: bajo contenido de materia seca, fenoles, mimosina y elevada degradación ruminal -cv. Cunningham, cv. 7 y cv. América-; G-5: elevado contenido de materia seca, fenoles y valor nutritivo medio -cv. K-8 y cv. K-67-; G-6: elevado porcentaje de materia seca y taninos, y baja degradabilidad -cv. Perú-. Conclusiones. La biomasa comestible de los cultivares Cunningham, América, 7, México, CNIA-250 y K-28 constituyen las mejores opciones para la alimentación de rumiantes.

  15. [Nutritional evaluation of the seeds of "ipil-ipil" (Leucaena leucocephala), "casco de vaca" (Bauhinia monandra) and scented carob (Albizia lebbeck)].

    Science.gov (United States)

    Abreu Peñate, M; Bencomo Hernández, A; Sampere Díaz, E; Farrás Fernández, I; Hernández Triana, M; Porrata Maury, C; Ponce de León Boloy, I

    1988-12-01

    Chemical composition, antinutritional factors and biological protein quality of raw and autoclaved (120 degrees C for 10 min) ipil-ipil (Leucaena leucocephala), casco de vaca (Bauhinia monandra) ard algarrobo de olor (Albizia lebbeck) seeds were determined. The trypsin inhibitor activity was 29, 120, and 150 TIU/mg of sample respectively. Autoclaving eliminated 59, 33 and 100% of the activity. Bauhinia monandra seed depicted a high hemagglutinating activity which was eliminated by autoclaving. Net protein utilization of raw and autoclaved seeds was 31 and 30, 21 and 55 and 29 and 49%, respectively. All seeds were free from cyanide and alkaloids. It is concluded that the relative low protein quality of the seeds would limit their use for human consumption.

  16. Desempenho germinativo da invasora Leucaena leucocephala (Lam. de Wit. e comparação com Caesalpinia ferrea Mart. ex Tul. e Caesalpinia pulcherrima (L. Sw. (Fabaceae Germination performance of the invader Leucaena leucocephala (Lam. de Wit. compared to Caesalpinia ferrea Mart. ex Tul. and C. pulcherrima (L. Sw. (Fabaceae

    Directory of Open Access Journals (Sweden)

    Nilson Gonçalves da Fonseca

    2011-03-01

    Full Text Available O sucesso das plantas na colonização de novas áreas está fortemente relacionado ao comportamento germinativo das sementes nas condições ambientais locais. O objetivo deste trabalho foi comparar o desempenho germinativo da exótica invasora Leucaena leucocephala ao das leguminosas (Caesalpinia ferrea, nativa e C. pulcherrima, exótica não consideradas invasoras. Sementes não escarificadas foram expostas às temperaturas de 15, 20, 25, 30, 35 e 40 °C, sob um fotoperíodo de 12 horas, durante 100 dias. Tanto a porcentagem final quanto a velocidade de germinação apresentaram diferenças significativas entre as três espécies. C. ferrea teve baixo desempenho, com temperatura ótima para a germinação a 25°C, porcentagem de germinação de 59% e IVG de 0,68 sementes d-1. Já C. pulcherrima, apresentou altas porcentagens de germinação em todas as temperaturas testadas, com faixa ótima entre 20-40 °C. As sementes de L. leucocephala apresentaram as menores porcentagens de germinação e temperatura ótima de 35 °C. O desempenho germinativo desta exótica não se sobressai ao das demais espécies estudadas e fatores como a pressão de propágulos, escarificação natural e bom desempenho em outras fases da vida devem contribuir para seu perfil de invasora.Success in establishing and colonizing new areas is directly related to germination behaviour of seeds under local environmental conditions. This work aimed to compare germination performance of the exotic invader Leucaena leucocephala to two legumes (Caesalpinia ferrea, native, and C. pulcherrima, exotic which are not considered invasive. Non-scarified seeds were exposed to constant temperatures of 15, 20, 25, 30, 35 and 40ºC, within a photoperiod of 12 hours, for 100 days. Both final germination percentage and germination speed showed significant differences among the three species. C. ferrea had low germination percentage, with optimal germination temperature at 25ºC, reaching

  17. Research Note: Predicting Leucaena leucocephala biomass from ...

    African Journals Online (AJOL)

    The amount of leaf and stem material removed by browsers can be precisely (r2 >0.90) and accurately (within 11% of the mean) predicted from DPB, thus providing a simple means of estimating browse offtake from leucaena trees. Keywords: Browse, firewood, regression, tree height, twig diameter. African Journal of Range ...

  18. Growth and N-uptake in sorghum plants manured with different amounts of Leucaena Leucocephala shoots as affected by time of application

    International Nuclear Information System (INIS)

    Kurdali, F.; Al-Shamma'a, M.

    2006-08-01

    A pot experiment was conducted throughout two successive years to determine the impact of adding four rates of nitrogen (0, 60, 120 and 180 kg N/ha) in the form of Leucaena leucocephala (lam.) de Wit green manure as affected by different time (T0, T15 and T30) of application (just before sowing, 15 and 30 days before sowing, respectively) on the performance of sorghum (Sorghum bicolor L.) using the indirect N-15 isotopic dilution technique. Results showed that leucaena leaves, used as a green manure, significantly increased dry matter production and N yield of sorghum. The effect was more pronounced in panicles than shoots. In the first year, N recoveries in sorghum of the total N contained in leucaena green manure ranged between 17-24% in T0, 14-24% in T15 and 15-19% in T30. The highest N recovery value was obtained in lowest rate of n treatment (N 60 ). Moreover, soil incorporated with leucaena green manure one month before planting enhanced both soil and mineral N fertilizer in sorghum plants. In the second year, total N uptake in sorghum (eg., panicles and the entire plant) increased with increasing amounts of N added as a leucaena green manure. N recoveries in sorghum ranged between 26-47% in T0, about 24% in T15 and 23-325 in T30 of the total N contained in leucaena green manure (LGM). As shown in the first year, the highest value of N recovery was obtained in lowest rate of N treatment. The beneficial effects of leucaena green manure on dry matter and N yield in sorghum was attributed not only to the additional N availability to the plant, but also to effects on the enhancement of soil N uptake, particularly when the incorporation was made before a sufficient time from sowing. The beneficial effect of green manuring with leucaena leaves at T15 and T30 was mainly resulted from enhancement of N uptake from this added material, as well as from soil and fertilizer N; whereas, it was only attributed to N uptake from green manure in the T0 treatment. Incorporation

  19. Growth and N-uptake in sorghum plants manured with different amounts of Leucaena Leucocephala shoots as affected by time of application

    International Nuclear Information System (INIS)

    Kurdali, F.; Al-Shamma'a, M.

    2007-01-01

    A pot experiment was conducted throughout two successive years to determine the impact of adding four rates of nitrogen (0, 60, 120 and 180 kg N/ha) in the form of Leucaena leucocephala (lam.) de Wit green manure as affected by different time (T0, T15 and T30) of application (just before sowing, 15 and 30 days before sowing, respectively) on the performance of sorghum (Sorghum bicolor L.) using the indirect N-15 isotopic dilution technique. Results showed that leucaena leaves, used as a green manure, significantly increased dry matter production and N yield of sorghum. The effect was more pronounced in panicles than shoots. In the first year, N recoveries in sorghum of the total N contained in leucaena green manure ranged between 17-24% in T0, 14-24% in T15 and 15-19% in T30. The highest N recovery value was obtained in lowest rate of n treatment (N60). Moreover, soil incorporated with leucaena green manure one month before planting enhanced both soil and mineral N fertilizer in sorghum plants. In the second year, total N uptake in sorghum (eg., panicles and the entire plant) increased with increasing amounts of N added as a leucaena green manure. N recoveries in sorghum ranged between 26-47% in T0, about 24% in T15 and 23-325 in T30 of the total N contained in leucaena green manure (LGM). As shown in the first year, the highest value of N recovery was obtained in lowest rate of N treatment. The beneficial effects of leucaena green manure on dry matter and N yield in sorghum was attributed not only to the additional N availability to the plant, but also to effects on the enhancement of soil N uptake, particularly when the incorporation was made before a sufficient time from sowing. The beneficial effect of green manuring with leucaena leaves at T15 and T30 was mainly resulted from enhancement of N uptake from this added material, as well as from soil and fertilizer N. Whereas, it was only attributed to N uptake from green manure in the T0 treatment. Incorporation

  20. Comportamiento productivo de vacas lecheras Mambí de Cuba en una asociación de gramíneas y Leucaena leucocephala cv. Cunningham Productive performance of Cuban Mambí dairy cows in an association of grasses and Leucaena leucocephala cv. Cunningham

    Directory of Open Access Journals (Sweden)

    Tania Sánchez

    2008-12-01

    Full Text Available Se evaluó el comportamiento de los indicadores productivos de vacas Mambí (¾ Holstein x ¼ Cebú de Cuba en una asociación de gramíneas mejoradas y Leucaena leucocephala cv. Cunningham, en una vaquería de la Empresa Genética de Matanzas. El pesaje de leche se realizó durante dos años al 100% de los animales en ordeño, con una frecuencia mensual. Se determinó la producción de leche por vaca en ordeño y la producción por vaca total, así como la influencia del bimestre de producción, la época del año, el número de la lactancia y el año, en el comportamiento productivo. Se alcanzó coincidencia entre la curva real y potencial de producción de leche, con una eficiencia superior al 85%; los mayores valores se obtuvieron en el período lluvioso. Al analizar la producción de leche por bimestre los mejores resultados se alcanzaron en julio-agosto. Además se lograron valores de producción por lactancia de 2 030-2 159 kg y por hectárea de 2 744-3 025 kg. A su vez, cuando se analizó el efecto de la época del año en el peso de los terneros al nacer no se encontraron diferencias significativas; los valores fueron superiores a 37,5 kg para ambos períodos. Se concluye que con la asociación de gramíneas mejoradas y leucaena se obtuvieron producciones totales, por lactancia y por hectárea aceptables, lo cual conllevó un adecuado nivel de rentabilidad en la vaquería, con ganancias superiores a los 1 000 pesos por hectárea.The performance of the productive indicators of Mambí cows (3/4 Holstein x ¼ Zebu from Cuba was evaluated in an association of improved grasses and Leucaena leucocephala cv. Cunningham, at a dairy unit of the Genetic Livestock Production Enterprise of Matanzas. The milk weighing was performed for two years in 100% of the milking animals, with a monthly frequency. Milk production per milking cow and total production per cow were determined, as well as the influence of production two-month period, season

  1. Combustion Characteristics of Torrefied Wood Samples of Pinus Carrebea and Leucaena Leucocephala Grown in Nigeria

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    Francis Akinyele FARUWA

    2016-12-01

    Full Text Available Torrefaction of selected wood samples of Pinus Carrebea and Leucaena Leucocephala were carried out at temperatures ranging from 200 to 300°C to improve the energy parameters of biomass and to determine the effect of torrefication temperature on the physical and combustion properties of wood selected from Pinus carrebea and Leuceanea leucocephala grown in Nigeria. In this process the biomass hemicellulose is degraded, maintaining its cellulose and lignin content. The samples were dried and heated to 225, 250, 275, and 300°C. Then the torrefied mass was subjected to basic property testing on proximate analysis and heating value was calculated in order to understand the differences between raw material and its torrefied products. Specifically, the wood blocks changed from light brown to black, stemming from the partial carbonization at the wood surface. When the temperature is 225°C, the color of the wood is between dark brown and once the torrefaction temperatures are 250 and 275°C, the colors of the wood become dark and darker respectively. The results of the proximate analysis also showed that increasing of torrefied temperature; volatile fraction was reduced while fixed carbon was increased with increase in temperature from 21.34 to 52.74 and 18.58 to 56.83 for Leucaena leucocephala and Pinus carreabeanus respectively at 225 to 300°C. The volatile content is decreased from 78.58% to 62.76% with increase in temperature. Ash content of were within 1.57-3.41% of torrefied wood. It could be observed that the High calorific value (HCV for pine ranged between 19.80 and 28.06MJ/Kg for the top, 19.93and 24.96MJ/kg for middle with 19.72and 25.96MJ/Kg for base. The values recorded for raw sample and at 275°C been the lowest and highest respectively. The High calorific value (HCV were found to be on the increase and nose dive at 300°C for the tree parts used in this research. The result revealed that for Leuceana the value increased from raw up to

  2. COMBUSTION CHARACTERISTICS OF TORREFIED WOOD SAMPLES OF PINUS CARREBEA AND LEUCAENA LEUCOCEPHALA GROWN IN NIGERIA

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    Joseph Adeola FUWAPE

    2016-12-01

    Full Text Available Torrefaction of selected wood samples of Pinus Carrebea and Leucaena Leucocephala were carried out at temperatures ranging from 200 to 300°C to improve the energy parameters of biomass and to determine the effect of torrefication temperature on the physical and combustion properties of wood selected from Pinus carrebea and Leuceanea leucocephala grown in Nigeria. In this process the biomass hemicellulose is degraded, maintaining its cellulose and lignin content. The samples were dried and heated to 225, 250, 275, and 300°C. Then the torrefied mass was subjected to basic property testing on proximate analysis and heating value was calculated in order to understand the differences between raw material and its torrefied products. Specifically, the wood blocks changed from light brown to black, stemming from the partial carbonization at the wood surface. When the temperature is 225°C, the color of the wood is between dark brown and once the torrefaction temperatures are 250 and 275°C, the colors of the wood become dark and darker respectively. The results of the proximate analysis also showed that increasing of torrefied temperature; volatile fraction was reduced while fixed carbon was increased with increase in temperature from 21.34 to 52.74 and 18.58 to 56.83 for Leucaena leucocephala and Pinus carreabeanus respectively at 225 to 300°C. The volatile content is decreased from 78.58% to 62.76% with increase in temperature. Ash content of were within 1.57-3.41% of torrefied wood. It could be observed that the High calorific value (HCV for pine ranged between 19.80 and 28.06MJ/Kg for the top, 19.93and 24.96MJ/kg for middle with 19.72and 25.96MJ/Kg for base. The values recorded for raw sample and at 275°C been the lowest and highest respectively. The High calorific value (HCV were found to be on the increase and nose dive at 300°C for the tree parts used in this research. The result revealed that for Leuceana the value increased from raw up to

  3. Supplementation of native grass hay with cowpea (Vigna unguiculata hay, wilted leucaena (Leucaena leucocephala forage, wilted tagasaste (Chamaecytisus palmensis forage or a wheat middling for young Friesian x Zebu (Boran crossbred steers

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    Tuomo Varvikko

    1992-03-01

    Full Text Available A 100-day experiment of a randomized block design was conducted with forty Friesian x Zebu (Boran crossbred growing steers to compare the value of wheat middling, an agro-industrial by-product (diet W, cowpea (Vigna unguiculata hay (diet C, and wilted forages of leucaena (Leucaena leucocephala, diet L and tagasaste (Chamaecytisus palmensis, diet T as cattle feed. These feeds were fed daily at a level of 1.5 kg (on an air dry basis to supplement the basal diet (diet H of native hay. A mineral supplement containing 50 g bone meal and 10 g common salt was also given daily. The steers were group-fed, but during the last two weeks at the end of the experiment the animals were housed individually in feeding pens to estimate the feed intake and apparent digestibilities of the diets. The animals were weighed at the beginning of the experiment, thereafter every two weeks, and finally at the end of the experiment. The animals consumed all the offered supplements, except for tagasaste forage, of which one third remained unconsumed. The mean daily total dry matter intake during the individual feeding period ranged from 4.0 to 5.0 kg between the diets (P

  4. EFFECT OF Dactyladenia barteri (Hook. f. ex Oliv.), Leucaena ...

    African Journals Online (AJOL)

    A two year field study was conducted to investigate the effects of prunings of Dactyladenia barteri (Hook. f. ex Oliv.), Leucaena leucocephala (Lam.) de Wit, Gliricidia sepium (Jacq.), and Senna siamea (Lam.) on the activity of earthworms and soil and worm cast properties. Earthworm activity was measured by quantifying ...

  5. Reproductive indices of Merino rams fed sun-cured Leucaena ...

    African Journals Online (AJOL)

    Reproductive indices of Merino rams fed sun-cured Leucaena leucocephala forage. I.V. Nsahlai, B.K. Byebwa, M.L.K. Bonsi. Abstract. (South African J of Animal Science, 2000, 30, Supplement 1: 111-112). Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  6. Disponibilidad de biomasa y hábitos alimenticios de ovinos en un sistema silvopastoril con Leucaena leucocephala, Hibiscus rosa-sinensis Y Cynodon nlemfuensis

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    Bernardino Candelaria-Martínez

    2017-01-01

    Full Text Available Se evaluó el efecto del pastoreo a los 50, 60 y 70 días en época de lluvias y seca con nortes que son los frentes fríos, que corresponden de octubre a enero junto con la disponibilidad, calidad de biomasa y hábitos alimenticios de ovinos en un sistema silvopastoril de pasto estrella (Cynodon nlemfuensis, tulipán (Hibiscus rosasinensis y leucaena (Leucaena leucocephala. Para cada tratamiento se utilizaron 2 parcelas de 8x24 m y 6 ovejas adultas raza pelibuey. La disponibilidad de biomasa en leucaena y tulipán se evaluó mediante cosecha total de 20 a 40 plantas por tratamiento. El pasto estrella se midió antes y después del pastoreo. Las 3 especies se separaron en componentes morfológicos, y se determinó proteína cruda y fibra detergente neutra en las hojas. Los hábitos de los ovinos se determinaron mediante observación directa. La disponibilidad de biomasa total, consumo por grupo y utilización del pasto estrella fueron mayores a los 70 días y en la época de lluvias. La proporción de hoja de las 3 especies fue mayor a los 50 días; por efecto de la época, fue más abundante en lluvias, nortes y seca para estrella, leucaena y tulipán, respectivamente. La disponibilidad de PC no varió (p>0,05 por efecto de frecuencia ni época de pastoreo. El mayor tiempo de consumo estuvo destinado a pasto estrella, tulipán y leucaena. Los diseños favorecieron los sistemas silvopastoriles multiasociados pues potenciaron los efectos positivos de sus relaciones. Las frecuencias de pastoreo se ajustaron a la época del año, bajo un modelo de manejo mixto de pastoreo y podas, para mejor utilización de la biomasa.

  7. Potential of different AM fungi (native from As-contaminated and uncontaminated soils) for supporting Leucaena leucocephala growth in As-contaminated soil.

    Science.gov (United States)

    Schneider, Jerusa; Bundschuh, Jochen; Rangel, Wesley de Melo; Guilherme, Luiz Roberto Guimarães

    2017-05-01

    Arbuscular mycorrhizal (AM) fungi inoculation is considered a potential biotechnological tool for an eco-friendly remediation of hazardous contaminants. However, the mechanisms explaining how AM fungi attenuate the phytotoxicity of metal(oid)s, in particular arsenic (As), are still not fully understood. The influence of As on plant growth and the antioxidant system was studied in Leucaena leucocephala plants inoculated with different isolates of AM fungi and exposed to increasing concentrations of As (0, 35, and 75 mg dm -3 ) in a Typic Quartzipsamment soil. The study was conducted under greenhouse conditions using isolates of AM fungi selected from uncontaminated soils (Acaulospora morrowiae, Rhizophagus clarus, Gigaspora albida; and a mixed inoculum derived from combining these isolates, named AMF Mix) as well as a mix of three isolates from an As-contaminated soil (A. morrowiae, R. clarus, and Paraglomus occultum). After 21 weeks, the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were determined in the shoots in addition to measuring plant height and mineral contents. In general, AM fungi have shown multiple beneficial effects on L. leucocephala growth. Although the activity of most of the stress-related enzymes increased in plants associated with AM fungi, the percentage increase caused by adding As to the soil was even greater for non-mycorrhizal plants when compared to AM-fungi inoculated ones, which highlights the phytoprotective effect provided by the AM symbiosis. The highest P/As ratio observed in AM-fungi plants, compared to non-mycorrhizal ones, can be considered a good indicator that the AM fungi alter the pattern of As(V) uptake from As-contaminated soil. Our results underline the role of AM fungi in increasing the tolerance of L. leucocephala to As stress and emphasize the potential of the symbiosis L. leucocephala-R. clarus for As-phytostabilization at moderately As

  8. Cinética de fermentación in vitro de Leucaena leucocephala y Megathyrsus maximus y sus mezclas, con o sin suplementación energética

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    Xiomara Gaviria

    Full Text Available Con el objetivo de caracterizar la cinética de fermentación in vitro de mezclas de Leucaena leucocephala y Megathyrsus maximus, se realizó un experimento in vitro de producción de gas en el que se incluyeron cinco tratamientos: 100 % de L. leucocephala (L100, 100 % de M. maximus (G100, 100 % de suplemento a base de harina de arroz y melaza (S100, y dos proporciones: L23-G77 y L26-G70-S4. Los forrajes se recolectaron durante ocho meses en un sistema silvopastoril intensivo (SSPi, perteneciente al Centro Agropecuario Cotové de la Universidad Nacional de Colombia. La producción máxima de gas varió en un rango de 156 (L100 a 247 mL g-1 sustrato (L26-G70-S4. El menor volumen de gas al punto de inflexión (57,5 mL se observó en L100, el cual fue diferente al de las mezclas y el suplemento (p < 0,05. La desaparición de la MS a las 96 h varió entre 53,8 % y 66,9 %, y fue mayor en L100 que en el resto de los tratamientos (p < 0,05. El menor valor de la producción de gas (1,31 mL por cada gramo de MS, fermentada a las 96 h, se observó en L100 (p < 0,05. Los resultados sugieren que la inclusión de leucaena aumentó la concentración de proteína de la dieta y redujo el contenido de FDN, lo que resulta positivo desde el punto de vista de la productividad animal. Se concluye que la utilización de forrajes de mayor calidad nutricional, como el de leucaena, modifica el perfil de fermentación de la dieta; por lo que la respuesta de las mezclas forraje-gramínea es diferente a la esperada, ya que depende de la respuesta individual de cada forraje.

  9. Response of rabbits to varying levels of cassava and Leucaena ...

    African Journals Online (AJOL)

    Response of rabbits to varying levels of cassava and Leucaena leucocephala leaf meal diets. ... Bulletin of Animal Health and Production in Africa ... An experiment was carried out to determine the performance, haematology, carcass characteristics and sensory evaluation of meat from rabbits (n = 30) fed varying levels of ...

  10. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: II. Influencia de los factores climáticos Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: II. Influence of climatic factors

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    Saray Sánchez

    2009-12-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala y su relación con algunos factores del clima, se realizó este experimento en la EEPF «Indio Hatuey». La descomposición de la hojarasca se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags; se registró diariamente el comportamiento de la temperatura media, la humedad relativa, la precipitación y los días con lluvias, en la estación metereológica situada a 1 km del área experimental. Se utilizó el análisis de correlación y regresión para conocer la interrelación entre las variables y los modelos de mejor ajuste. Se consideró, como variables independientes, los factores climáticos estudiados, y como variable dependiente el porcentaje de biomasa perdida. De forma general, los resultados demostraron que el comportamiento de la descomposición de la hojarasca, tanto en la guinea como en la leucaena, estuvo relacionado con los factores climáticos que prevalecieron durante el período experimental y, por tanto, es posible explicar este proceso en ambos pastizales a partir de la acción conjunta de la temperatura, la humedad relativa y la precipitación.With the objective of determining the litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala and its relationship to some climate factors, this trial was conducted at the EEPF «Indio Hatuey». Litter decomposition was determined as the loss of biomass through time, with regards to initial weight. For studying the decomposition dynamics the method of litter bags was used; the performance of mean temperature, relative humidity, rainfall and days with rain, was daily recorded at the meteorological station located 1 km away from the experimental area. . The

  11. Determinación de compuestos hidrocarbonados en la pared celular de P. maximum y L. leucocephala en silvopastoreo Determination of hydrocarbonated compounds in the cell wall from P. maximum and L. leucocephala under silvopastoral system conditions

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    Tania Sánchez

    2009-09-01

    Full Text Available Con el objetivo de determinar la concentración de n-alcanos y alcoholes de cadena larga en la pared celular de Panicum maximum cv. Likoni y Leucaena leucocephala cv. Cunningham, se realizó un estudio en una asociación de gramíneas mejoradas y leucaena de 10 años de establecida, la cual ocupa un área de 1,6 ha. Se seleccionaron dichas especies por ser las más representativas en la composición florística. Las muestras se colectaron de enero a diciembre del 2005 y se secaron. La concentración de n-alcanos de cadena impar fue de 167,97 y 222,96 mg/kg de MS y 134,11 y 137,27 mg/kg de MS para guinea y leucaena, en el período poco lluvioso y en el lluvioso, respectivamente. A su vez la concentración de alcoholes de cadena par para la leucaena presentó un valor mayor(2 754,60 y 3 830,18 mg/kg de MS para el período poco lluvioso y lluvioso, respectivamente, que en la guinea (2 571,73-3 679,65 mg/kg de MS para cada período, respectivamente. Se concluye que la concentración de n-alcanos de cadena larga impar fue baja para P. maximum y L. leucocephala en ambos períodos del año; sin embargo, presentaron concentraciones elevadas de alcoholes de cadena larga par, que pudieran ser utilizados como marcadores naturales en las dos especies.With the objective of determining the concentration of n-alkanes and long-chain alcohols in the cell wall of Panicum maximum cv. Likoni and Leucaena leucocephala cv. Cunningham, a study was conducted in an association of improved grasses and leucaena ten years after being established, which occupies an area of 1,6 ha. Such species were selected for being the most representative ones in the floristic composition. The samples were collected from January to December, 2005 and were dried. The concentration of odd-chain n-alkanes was 167,97 and 222,96 mg/kg DM and 134,11 and 137,27 mg/kg DM for Guinea grass and leucaena in the dry and rainy season, respectively. In turn, the concentration of even-chain alcohols for

  12. Abiotic stress induces change in Cinnamoyl CoA Reductase (CCR) protein abundance and lignin deposition in developing seedlings of Leucaena leucocephala.

    Science.gov (United States)

    Srivastava, Sameer; Vishwakarma, Rishi K; Arafat, Yasir Ali; Gupta, Sushim K; Khan, Bashir M

    2015-04-01

    Aboitic stress such as drought and salinity are class of major threats, which plants undergo through their lifetime. Lignin deposition is one of the responses to such abiotic stresses. The gene encoding Cinnamoyl CoA Reductase (CCR) is a key gene for lignin biosynthesis, which has been shown to be over-expressed under stress conditions. In the present study, developing seedlings of Leucaena leucocephala (Vernacular name: Subabul, White popinac) were treated with 1 % mannitol and 200 mM NaCl to mimic drought and salinity stress conditions, respectively. Enzyme linked immunosorbant assay (ELISA) based expression pattern of CCR protein was monitored coupled with Phlorogucinol/HCl activity staining of lignin in transverse sections of developing L. leucocephala seedlings under stress. Our result suggests a differential lignification pattern in developing root and stem under stress conditions. Increase in lignification was observed in mannitol treated stems and corresponding CCR protein accumulation was also higher than control and salt stress treated samples. On the contrary CCR protein was lower in NaCl treated stems and corresponding lignin deposition was also low. Developing root tissue showed a high level of CCR content and lignin deposition than stem samples under all conditions tested. Overall result suggested that lignin accumulation was not affected much in case of developing root however developing stems were significantly affected under drought and salinity stress condition.

  13. Biochemical characterization of recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) from Leucaena leucocephala.

    Science.gov (United States)

    Sonawane, Prashant; Vishwakarma, Rishi Kishore; Khan, Bashir M

    2013-07-01

    Recombinant cinnamoyl CoA reductase 1 (Ll-CCRH1) protein from Leucaena leucocephala was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. Optimum pH for forward and reverse reaction was found to be 6.5 and 7.8 respectively. The enzyme was most stable around pH 6.5 at 25°C for 90 min. The enzyme showed Kcat/Km for feruloyl, caffeoyl, sinapoyl, coumaroyl CoA, coniferaldehyde and sinapaldehyde as 4.6, 2.4, 2.3, 1.7, 1.9 and 1.2 (×10(6) M(-1) s(-1)), respectively, indicating affinity of enzyme for feruloyl CoA over other substrates and preference of reduction reaction over oxidation. Activation energy, Ea for various substrates was found to be in the range of 20-50 kJ/mol. Involvement of probable carboxylate ion, histidine, lysine or tyrosine at the active site of enzyme was predicted by pH activity profile. SAXS studies of protein showed radius 3.04 nm and volume 49.25 nm(3) with oblate ellipsoid shape. Finally, metal ion inhibition studies revealed that Ll-CCRH1 is a metal independent enzyme. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Effect of combined inoculations of Rhizobium-Arbuscular Mycorrhiza in Leucaena leucocephala CV: Perú

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    Lázaro Jesús Ojeda Quintana

    2014-07-01

    Full Text Available The work was conducted at the Experimental Station of Soil and Fertilizer “Escambray” land of farmers and associated rural extension. The experimental design was randomized blocks, and treatments: Rizhobium loti V-4033 (Research Institute of Pastures and Forages, mycorrhizal fungi trainers, Rhizobium +mycorrhiza fungi trainers, nitrogen and total control. Inoculation with my corrhiza forming fungi was performed at 10 g/bag Certificate MicoFert Strain the Institute of Ecology and Systematics-3: Glomus spurcum, Topes de Collantes, 85 % colonization of rootlets, while the Rhizobium was inoculated in a dose of 50 g/kg of seed. Variant was nitrogen at 25 kg/ha of urea. The plots occupied 18m2 , with an area of 9 m2 evaluable. When the plants reached 7.5 months and an average height of 143.4 cm proceeded to make the Court of establishment and then four foliage cuts were made every 90 days. Each cut dry biomass yield, and phosphorus content was determined crude protein. The combined inoculation of Rhizobium and mycorrhiza fungi Makers increased the yield of dry biomass, and phosphorus content of crude protein. We conclude proposing the adoption of an alternative methodology using mycorrhiza formers Fungi and Rhizobium in Leucaena leucocephala as a way to increase the yield of dry biomass, decreasing mineral fertilization and contribute to environmental protection

  15. Efecto del almacenamiento al ambiente en semillas de Leucaena leucocephala cv. Cunningham sometidas a hidratación parcial Effect of storage under ambient conditions on seeds from Leucaena leucocephala cv. Cunningham subject to partial hydration

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    Yolanda González

    2012-12-01

    Full Text Available El objetivo del trabajo fue estudiar el efecto del almacenamiento al ambiente en la germinación de las semillas de Leucaena leucocephala cv. Cunningham sometidas a hidratación parcial. Los tratamientos fueron: control, sin escarificación (T0; escarificación térmica (ET con H2O a 80°C, durante dos minutos (T1; ET más hidratación parcial, en bandeja con agua corriente por 28 horas (T2; ET más hidratación parcial, en saco de yute humedecido con agua corriente por 28 horas (T3; ET más hidratación parcial, en bandeja con agua corriente y TMTD al 0,1% (plaguicida por 28 horas (T4; ET más hidratación parcial, en saco de yute humedecido con agua corriente y TMTD al 0,1% (plaguicida por 28 horas (T5. Las semillas hidratadas se deshidrataron durante 72 horas al aire y a la sombra, antes de almacenarlas. Se midió la germinación y la viabilidad a 0, 1, 2, 3, 4, 6, 18, 30 y 42 meses. Se utilizó un diseño totalmente aleatorizado y cuatro réplicas por tratamiento. Hubo diferencias significativas (PThe objective of the work was to study the effect of storage under ambient conditions on the germination of seeds from Leucaena leucocephala cv. Cunningham subject to partial hydration. The treatments were: control, no scarification (T0; thermal scarification (TS with H2O at 80ºC, for two minutes (T1; TS plus partial hydration, on tray with tap water for 28 hours (T2; TS plus partial hydration, in jute sac moist with tap water for 28 hours (T3; TS plus partial hydration in tray with tap water and TMTD at 0,1% (pesticide for 28 hours (T4; TS plus partial hydration, in jute sac moist with tap water and TMTD at 0,1% (pesticide for 28 hours (T5. The hydrated seeds were dehydrated during 72 hours exposed to air and under shade, before being stored. Germination and viability were measured after 0, 1, 2, 3, 4, 6, 18, 30 and 42 months. A completely randomized design and four replications per treatment were used. There were significant differences (P<0

  16. Caracterización cultural y morfológica e identificación de 12 aislamientos fungosos de semillas de Leucaena leucocephala cv. Perú Cultural and morphological characterization and identification of 12 fungal isolations in seeds of Leucaena leucocephala cv. Peru

    Directory of Open Access Journals (Sweden)

    J. C Lezcano

    2010-03-01

    Full Text Available La presente investigación tuvo como objetivo identificar los agentes fungosos asociados a las semillas de Leucaena leucocephala cv. Perú almacenadas al ambiente, a partir de la caracterización cultural y morfológica de 12 aislamientos puros; estos se obtuvieron de la siembra de las estructuras fúngicas (vegetativas y/o reproductivas, en placas Petri (9 cm de diámetro que contenían Agar Papa Dextrosa (APD y Agar Malta (AM. Las placas se incubaron durante 10 días a 25ºC, con alternancia de 8 h luz/16 h oscuridad o a oscuridad constante, según los requerimientos de cada organismo. Se identificaron siete agentes fungosos asociados a las semillas, los cuales se clasificaron teniendo en cuenta los caracteres culturales y morfológicos, y se corroboraron con las claves taxonómicas. Ello permitió agrupar: Penicillium expansum Link, Rhizopus stolonifer Ehrenb. ex Fr., Cladosporium sphaerospermum Penz., Chaetomium indicum Corda, Alternaria alternata (Fr Keissl., Pestalotia sp. y Trichoderma sp. Dichos caracteres constituyen una herramienta importante para la identificación de los hongos hasta el nivel de especie, por lo que se recomienda realizar nuevos estudios con los aislamientos #9 y #11 con vista a completar la identificación hasta la especie en el caso de los géneros Trichoderma y Pestalotia; así como identificar las especies fungosas del resto de los aislamientos.The objective of this study was to identify the fungal agents associated to seeds of Leucaena leucocephala cv. Peru stored under ambient conditions, from the cultural and morphological characterization of 12 pure isolations; they were obtained from planting the fungal structures (vegetative and/or reproductive, in Petri dishes (9 cm diameter which contained Potato Dextrose Agar (PDA and Malt Agar (MA. The dishes were incubated for 10 days at 25ºC, alternating 8 h light/16 h darkness or at constant darkness, according to the requirements of each organism. Seven fungal

  17. Avaliação de genótipos de Leucaena spp. nas condições edafoclimáticas de São Carlos, SP: I. caracterização fenotípica e avaliação agronômica Evaluation of Leucaena spp. genotypes in the edaphic and climatic conditions of São Carlos, SP: I. phenotypical characterization and agronomical evaluation

    Directory of Open Access Journals (Sweden)

    A.C.P. de A. Primavesi

    1994-04-01

    Full Text Available Para avaliar genótipos promissores de Leucaena spp., foi instalado experimento em Latossolo Vermelho-Amarelo distrófico, na área da EMBRAPA-CPPSE em São Carlos, situada a 22°01'S e 47°53'W, com altitude de 856 m e média de precipitação anual de 1502 mm. Foram testados os seguintes genótipos: Leucaena leucocephala cv. Texas 1074 (T1, L.leucocephala 29 A9 (T2, L.leucocephala 11 x L.diversifolia 25 (T3, L.leucocephala 11 x L.leucocephala 26 (T4, L.leucocephala 24-19/2-39 X L.diversifolia 26 (T5 e L.leucocephala cv. Cunningham (testemunha. Através das avaliações efetuadas durante o período de estabelecimento (15 meses, verificou-se que: a as plantas de L.leucocephala 24-19/2-39 x L.diversifolia 26 se mostraram mais ramificadas e com maior produção de sementes; b as plantas de L.leucocephala 11 x L.diversifolia 26 apresentaram a maior produção de matéria seca consumível; c os materiais apresentaram brotação após o corte, semelhante ou inferior à testemunha.To test promising genotypes of Leucaena spp., selected in a breeding program, an experiment was conducted in a distrofic Red-Yellow Latossol, at the experimental station of EMBRAPA/CPPSE, São Carlos,SP, located at 22°01' and 47°53'W, altitude of 856 m and with a mean annual precipitation of 1502 mm. The following genotypes were tested: L.leucocephala cv. Texas 1074 (T1, L.leucocephala 29 A9 (T2, L.leucocephala 11 x L.diversifolia 25 (T3, L.leucocephala 11 x L.diversifolia 26 (T4, L.leucocephala 24-19/2-39 x L.diversifolia 26 (T5 and L.leucocephala cv. Cunningham (control. Evaluations were performed during the establishment period (fifteen months and it was concluded that: a the plants of L.leucocephala 24-19/2-39 x L.diversifolia 26, with early flowering, were the most branched and presented the greatest seed yield; b the plants of L.leucocephala 11 x L.diversifolia 26, showed the greatest edible dry matter yield; c the genotypes presented similar or worse growth, than

  18. APPARENT DIGESTIBILITY OF RHODE ISLAND RED HEN DIETS CONTAINING Leucaena leucocephala AND Moringa oleifera LEAF MEALS

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    Khaled Abouelezz Fouad Mohammed

    2012-05-01

    Full Text Available This study consisted of two trials aimed to evaluate the dietary digestibility by Rhode Island Red (RIR hens' fed on different levels of Leucaena leucocephala (LLM or Moringa oleifera (MOLM. In each experiment, thirty six Rhode Island Red hens at 36 weeks of age were randomly divided into four groups each of nine birds which were allocated in individual cages. The four groups were corresponded to four dietary treatments containing 0 (control, 5, 10 and 15 % of LLM (Exp 1 or MOLM (Exp 2. All groups received smashed diets containing similar metabolizable energy and crude protein (16% CP and 2900 kcal ME/kg diet, as fed basis. The hens were fed the experimental diets for six weeks and during the last four days, feed intake was individually recorded every day and excreta was totally collected twice daily and weighed individually. Considerable amounts of CP were found in LLM (23.61% DM and MOLM (19.76% DM. The dietary treatments had no significant effect on the intake of dry matter (DM, organic matter (OM, gross energy (GE, crude protein (CP or neutral detergent fiber (NDF in both experiments, while the acid detergent fibers (ADF consumption increased linearly (P

  19. Curvas de índice de sítio para leucena [Leucaena leucocephala (Lam. De Wit] no agreste de Pernambuco

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    Emanuell Florencio Passos Martins

    2007-01-01

    Full Text Available The main goal of this work was to set and compare site index curves for leucena [Leucaena leucocephala (Lam. de Wit] variety Hawaii (cv K8 in Agreste of Pernambuco. The data set came from Empresa Pernambucana de Pesquisa Agropecuária (IPA, Experimental Station of Caruaru, in which 544 trees cultivated with and without organic compound were measured 19 times during the period of 1990 – 2003. The models of Schumacher, Chapman-Richards, Silva-Bailey, Mitscherlich, Weibull and Clutter-Jones were tested and compared. To select the best equations, the Index of Fit (IF, standard error of estimate (S yx %, identity model test and the graphic of residuals distribution were used and results show that the model of Clutter-Jones provided a better IF for both treatments. The graphic of residual distribution did not show tendency among the models. The model identity test showed no differences among the models tested. As Schumacher is model has been used frequently in forestry and presented the smallest number of parameters, it deserves special focus in studies of site index.

  20. Evaluación del establecimiento de Leucaena leucocephala cv. Cunningham en una finca ganadera del municipio de Perico, Matanzas, Cuba

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    Katia Bover

    Full Text Available El objetivo de este trabajo fue evaluar el establecimiento de Leucaena leucocephala cv. Cunningham en una finca de la cooperativa de créditos y servicios (CCS Ramón Rodríguez Milián, del municipio de Perico. Se trabajó en un área de 6 ha, dividida en cinco cuartones, y se realizó una preparación en franjas de 2 m de ancho. Se determinó la supervivencia después del trasplante, la altura, el número de ramas y la composición florística del pastizal; así como el efecto de las labores de limpieza y el daño causado por los animales en la altura. Se aplicó un análisis de varianza y los datos se procesaron con el paquete estadístico SPSS® versión 10.0 para Windows XP. La supervivencia de las plantas fue de 98 %; la labor de limpieza tuvo un efecto positivo en el crecimiento, mientras que la defoliación de la planta por los animales afectó el establecimiento. La población de pastos naturales (jiribilla y pitilla se mantuvo alrededor de 66 % y la de las principales leguminosas volubles (teramnus, glycine y siratro disminuyó de 12 % en el tercer mes después de realizado el trasplante, a 6 % en el decimoquinto mes. El sistema se consideró establecido cuando las plantas sobrepasaron los 2 m de altura. Se concluye que la labor de limpieza influyó positivamente en el comportamiento de la altura y el establecimiento de L. leucocephala, mientras que las defoliaciones causadas por los animales lo retrasaron.

  1. Consideraciones acerca de la Leucaena leucocephala cv. X: una nueva opción forrajera para un ecosistema ganadero con suelos ácidos e infértiles Considerations about Leucaena leucocephala cv. X: A new forage choice for a livestock ecosystem with acid and infertile soils

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    A Pérez

    2008-12-01

    Full Text Available El presente estudio se realizó a partir de una búsqueda de información por diversas páginas Web, revistas de impacto, otras de carácter nacional e internacional, así como las más diversas fuentes de información, relacionada con la capacidad de adaptación del género Leucaena a los diferentes tipos de suelo, con énfasis en la acidez y el grado de encharcamiento. La revisión proporcionó las limitantes de adaptación del género y de la especie L. leucocephala a dichas condiciones. El descubrimiento de las posibilidades de germoplasma adaptables a esos tipos de suelos, abrió un preámbulo para encontrar plantas arbóreas para los ecosistemas con acidez y humedad, de los que Cuba y el Trópico poseen más del 33% en las áreas cultivadas. Se brinda información internacional, así como resultados de investigación acerca de variedades de esta especie, la fase de establecimiento, la fenología de la planta, la adaptación a diferentes tipos de suelo, la respuesta a la poda y el comportamiento con animales, fundamentalmente en la producción de leche, como respuesta al consumo y suministro de L. leucocephala cv. X. Los resultados permiten afirmar que el cv. X, junto a otras gramíneas y leguminosas importantes para este tipo de ecosistema ganadero, puede contribuir significativamente a transformar el panorama económico, productivo y ambiental del entorno de las zonas que presenten similares condiciones. Se concluye que esta leguminosa arbórea puede ser un buen árbol forrajero para suelos ácidos (pH entre 4,6 y 5,1, húmedos e infértiles, lo que le confiere una plasticidad ecológica superior a la considerada hasta el momento. Se recomienda que este cultivar continúe extendiéndose a otras zonas con condiciones similares a las estudiadas. Además, debe continuarse su evaluación para proponerla como variedad comercial.The study was carried out from a search for information through different Web pages, impact journals, other national

  2. Siembra directa con Leucaena leucocephala (Lam. de Wit. Para producción de forraje en el jardín botánico “Carlos Liscano”, Mérida, Venezuela

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    J. Petit-Aldana

    2005-01-01

    Full Text Available La siembra directa es un método económico para establecer programas de producción de forraje con leguminosas arbustivas, La Leucaena leucocephala (Lam. de Wit. es una leguminosa de tipo arbustivo, utilizada en agricultura, ganadería y en la recuperación de tierras, tiene gran adaptabilidad, alto valor forrajero y se cataloga entre las principales especies de uso múltiple en agroforestería. El objetivo fue establecer un ensayo de siembra directa utilizando los métodos de siembra al voleo, surcos y hoyos con Leucaena leucocephala (Lam. de Wit en un área del Jardín Botánico “Carlos Liscano” de la Facultad de Ciencias Forestales y Ambientales de la Universidad de Los Andes, Venezuela, a fin de probar su efectividad para planes futuros de establecimiento de bancos forrajeros. Se estableció el ensayo en un diseño completamente al azar en un experimento factorial (2 x 3, con 4 bloques (repeticiones. Los factores experimentales fueron: Factor A: 1 terreno arado 2 terreno no arado y Factor B: 1 siembra al voleo, 2 siembra en hoyos y 3 siembra en surcos. Se encontró que el método más exitoso de siembra es el surco, tanto en terreno arado como no arado. Se determinó que la emergencia está entre el día cuatro y dieciocho después de la siembra. Tres meses después la mayor abundancia de plantas se presentó en los bloques arados con sistema de siembra al voleo, aunque los mejores promedios de altura se encontraron en los bloques con arado y la siembra en surcos.

  3. DESCOMPOSICIÓN Y LIBERACIÓN DE NITRÓGENO Y MATERIA ORGÁNICA EN HOJAS DE Leucaena leucocephala (Lam. de Wit, Guazuma ulmifolia Lam. Y Moringa oleifera Lam. EN UN BANCO MIXTO DE FORRAJE

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    Judith Petit-Aldana

    2012-01-01

    Full Text Available Se evaluaron las tasas de descomposición, la liberación de N y MO en hojas de Leucaena leucocephala (Lam. de Wit, Guazuma ulmifolia Lam. y Moringa oleifera Lam. en un banco mixto de forraje en Yucatán, México, en las épocas de lluvias y sequía, en un diseño de bloques completos al azar, cinco tratamientos y cuatro repeticiones. Se llenaron 120 bolsas con hojas frescas de las especies colectadas, y se colocaron en cada unidad experimental. Se evaluaron tres periodos de incubación para cada tratamiento: cuatro, ocho, y 16 semanas por cada época. A finales del experimento se observó que el proceso de descomposición fue más rápido en la temporada de lluvias. La pérdida de peso y la liberación de N y MO fueron más aceleradas en M. oleifera en monocultivo y en la asociación L. leucocephala con M. oleifera. Los patrones de descomposición de todas las especies siguieron el modelo exponencial simple, con más del 80 % de la masa inicial incorporada al final del periodo de estudio. Se concluye que L. leucocephala, G. ulmifolia y M. oleifera en monocultivo y asociadas, demostraron su capacidad para producir considerables cantidades de materia orgánica y liberar importantes cantidades de N en cortos periodos.

  4. Leucaena toxicity: a new perspective on the most widely used forage tree legume

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    Michael J. Halliday

    2013-09-01

    Full Text Available The tree legume Leucaena leucocephala (leucaena is a high quality ruminant feed, vitally important for livestock production in the tropics, despite the presence of mimosine in the leaves. This toxic non-protein amino acid has the potential to limit productivity and adversely affect the health of animals. In the 1980s, the ruminal bacterium Synergistes jonesii was discovered and subsequently distributed in Australia as an oral inoculum to overcome these toxic effects. However, in recent times, a number of factors, including: surveys of the status of toxicity worldwide; improved understanding of the chemistry and mode of action of the toxins; new techniques for molecular sequencing; and concerns about the efficacy of the in vitro inoculum; have cast doubt on some past understanding of leucaena toxicity and provide new insights into the geographical spread of S. jonesii. There is also confusion and ignorance regarding the occurrence and significance of toxicity in many countries worldwide. Ongoing research into the taxonomy and ecology of the Synergistetes phylum, improved methods of inoculation, and improved management solutions, along with aware-ness-raising extension activities, are vital for the future success of leucaena feeding systems.

  5. Dormancia y tratamientos pregerminativos en las semillas de Leucaena spp. cosechadas en suelo ácido Dormancy and pregerminative treatments in Leucaena spp. seeds harvested on acid soil

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    Yolanda González

    2009-12-01

    Full Text Available Se desarrolló un experimento con semillas de accesiones de Leucaena spp. cosechadas en suelo ácido y almacenadas bajo condiciones ambientales, para determinar el período e intensidad de la dormancia y su ruptura. Para ello se empleó un diseño de clasificación simple y cuatro réplicas, con los siguientes tratamientos: 1 semilla sin tratar (control; 2 corte de cubierta; y 3 agua a 80°C durante 2 minutos. En cada una de las accesiones hubo diferencias significativas entre los tratamientos aplicados y los mayores valores de germinación se encontraron con el corte de cubierta. Todas las accesiones mostraron estado dormático (entre 10 y 98%, el cual se apreció en la germinación del control y en la viabilidad con el corte de cubierta. Los mayores valores de dormancia en las semillas cosechadas en el 2006 se detectaron en L. macrophylla CIAT 17233, L. macrophylla CIAT 17231, L. diversifolia CIAT 17270 y L. leucocephala IH-1140, cuya dureza fue de 98,0; 97,0; 80,0 y 74,7%, respectivamente; en las cosechadas en el 2003 y 2004, los porcentajes de dureza fueron de 89,0; 69,0 y 60,0% para L. lanceolata CIAT 17252, L. macrophylla CIAT 17238 y L. leucocephala cv. K-67, respectivamente. Se concluye que las semillas de las accesiones presentaron dormancia poscosecha, que varió entre 10 y 98%. Además la escarificación térmica provocó su ruptura, por lo que se recomienda aplicar este procedimiento antes de la siembra a las semillas de Leucaena spp. que se cosechen en suelo ácido de Cascajal.A trial was conducted with seeds of Leucaena spp accessions harvested on acid soil and stored under ambient conditions, in order to determine the period and intensity of dormancy and its breaking. For that purpose a simple classification design and four replications were used, with the following treatments: 1 untreated seed (control; 2 coat cut; and 3 water at 80ºC for 2 minutes. In each one of the accessions there were significant differences among the

  6. Leucaena leucocephala pod seed protein as an alternate to animal protein in fish feed and evaluation of its role to fight against infection caused by Vibrio harveyi and Pseudomonas aeruginosa.

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    Verma, Vipin Kumar; Rani, Kumari Vandana; Kumar, Shiva Raj; Prakash, Om

    2018-05-01

    The laboratory acclimatized Clarias gariepinus (80 ± 10 g) were divided into six groups and five subgroups each containing 10 fish. A fish feed was reconstituted by adding 33% powder of Leucaena leucocephala seed in place of fish trash. Group B, C and E were fed on reconstituted feed and group A, D and F were fed on artificial feed containing animal protein for 7 days prior to start of experiments. Then Group B was challenged with BSA while other groups were challenged with Vibrio harveyi (Group C, D) and Pseudomonas aeruginosa (Group E, F). Group A was used as negative control (not challenged with antigen). The fish were challenged on weekly intervals till 28th day. Blood was collected from one subgroup of each group on day 7, 14, 21 & 28 and finally sacrificed on day 35. Change in body weight, liver function tests (SGOT, SGPT) and serum ALP levels were monitored. The phagocytic index, percentage phagocytosis and nitric oxide levels were measured in macrophages isolated from spleen and head kidney. The levels of total fish immunoglobulin were also measured following indirect ELISA. The results showed improved immune response in fish fed on 33% L. leucocephala pod seed reconstituted feed; however their specific growth rate was low. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Antidiabetic and antioxidant activities of seed extract from Leucaena leucocephala (Lam. de Wit

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    Pichaya Chowtivannakul

    2016-09-01

    These results indicated that seed extract from L. leucocephala has antidiabetic and antioxidant activities. The antioxidant activity is likely due to the phenolic content. An application of this extract should be considered as it can affect renal function by reducing the levels of albumin, ALP and total protein.

  8. Evaluation of the complexes of galactomannan of Leucaena leucocephala and Co2+, Mn2+ , Ni2+ and Zn2+

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    Mercê Ana Lucia R.

    2000-01-01

    Full Text Available The binding constants for the complexed species formed in aqueous solution between galactomannan of Leucaena leucocephala and the metal ions Co2+, Mn2+, Ni2+ and Zn2+ were determined by potentiometric titrations. The calculated values showed Ni2+ as the best Lewis acid towards the Lewis base -OH groups of the sugar monomers, with Zn2+ being the poorest. For all systems, a higher percentage of the complexed species was present near pH=7.0, although complexed species existed over a wide range of acidic and basic pH values. The isolated solid complexes were studied by TG-DSC thermal analysis and by EPR spectroscopy. The thermal profiles obtained showed higher thermal resistance to final degradation than the biopolymer alone for the complexed species ML having the smallest log K values. The EPR spectra confirmed the complexation of the metal ions via the Lewis base deprotonated hydroxyl groups (-O and showed that the distances between metal ions in the complexed biopolymer structure depend on the nature of the metal ion. The ability of galactomannans to complex a variety of metal ions in their web like structure and the resistance to high temperatures and a wide range of pH values of these complexes open new perspectives in possible industrial uses whenever these properties are required, such as in bioremediation of waste waters and in the application of slow-release fertilizers.

  9. Protein Binding Capacity of Different Forages Tannin

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    Yusiati, L. M.; Kurniawati, A.; Hanim, C.; Anas, M. A.

    2018-02-01

    Eight forages of tannin sources(Leucaena leucocephala, Arachis hypogaea, Mimosa pudica, Morus alba L, Swietenia mahagoni, Manihot esculenta, Gliricidia sepium, and Bauhinia purpurea)were evaluated their tannin content and protein binding capacity. The protein binding capacity of tannin were determined using precipitation of bovine serum albumin (BSA). Swietenia mahagonihas higest total tannin level and condensed tannin (CT) compared with other forages (P<0.01). The Leucaena leucocephala has highest hydrolysable tannin (HT) level (P<0.01). The total and condensed tannin content of Swietenia mahagoni were 11.928±0.04 mg/100 mg and 9.241±0.02mg/100mg dry matter (DM) of leaves. The hydrolysable tannin content of Leucaena leucocephala was 5.338±0.03 mg/100 mg DM of leaves. Binding capacity was highest in Swietenia mahagoni and Leucaena leucocephala compared to the other forages (P<0.01). The optimum binding of BSA to tannin in Leucaena leucocephala and Swietenia mahagoniwere1.181±0.44 and 1.217±0.60mg/mg dry matter of leaves. The present study reports that Swietenia mahagoni has highest of tannin content and Leucaena leucocephala and Swietenia mahagoni capacity of protein binding.

  10. Composión trófica de la comunidad insectil en dos agroecosistemas ganaderos con Leucaena leucocephala (Lam. de wit y Panicum maximum Jacq. Trophic composition of the insect community in two livestock production agroecosystems with Leucaena leucocephala (Lam. de wit and Panicum maximum Jacq.

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    O Alonso

    2011-12-01

    Full Text Available Con el objetivo de definir los principales grupos funcionales en la comunidad de insectos presentes en dos áreas compuestas por la asociación de Leucaena leucocephala cv. Perú y Panicum maximum cv. Likoni (un sistema silvopastoril y un campo de semilla, respectivamente, ambas localizadas en la Estación Experimental de Pastos y Forrajes "Indio Hatuey", se muestrearon cada 15 días, durante tres años, las hojas, las inflorescencias y las legumbres de la leguminosa y el follaje de la gramínea, para colectarlos. La clasificación de los grupos se realizó a partir de: la identificación de cada especie insectil, la información que ofrece la literatura acerca de su hábito principal de alimentación y las observaciones realizadas en el campo. Con estos elementos se definieron los fitófagos y los benéficos, y como subgrupos de estos últimos: los depredadores, los parasitoides, los polinizadores, los descomponedores de la materia orgánica, los coprófagos y los micófagos. En total se identificaron 113 especies de insectos, 63 con hábitos fitófagos y los 50 restantes benéficos. En el estrato arbóreo se encontraron 88 especies, 49 fitófagas (56% y 39 benéficas (44%; y 103 en el herbáceo, 59 insectos fitófagos (57% y 44 benéficos (43%; 78 especies coincidieron en los dos estratos. Se destaca que en ambos predominaron los depredadores y los parasitoides de los órdenes Hymenoptera, Coleoptera y Diptera, tales como: Cycloneda sanguinea limbifer Casey, Coccinella maculata (De Geer, Chilocorus cacti Linnaeus, Conura sp., Pimpla marginella (Brullé y Rogas sp. Se concluye que la estructura y función de la comunidad de insectos mostró un número relativamente mayor de insectos fitófagos con respecto a los benéficos; sin embargo, fue importante el predominio de los enemigos naturales, responsables de la actividad reguladora de las poblaciones de fitófagos, a las que mantienen por debajo del umbral de daño económico en el cultivo de la

  11. Effects of condensed tannin fractions of different molecular weights from a Leucaena leucocephala hybrid on in vitro methane production and rumen fermentation.

    Science.gov (United States)

    Saminathan, Mookiah; Sieo, Chin Chin; Abdullah, Norhani; Wong, Clemente Michael Vui Ling; Ho, Yin Wan

    2015-10-01

    Molecular weights (MWs) and their chemical structures are the primary factors determining the influence of condensed tannins (CTs) on animal nutrition and methane (CH4 ) production in ruminants. In this study the MWs of five CT fractions from Leucaena leucocephala hybrid-Rendang (LLR) were determined and the CT fractions were investigated for their effects on CH4 production and rumen fermentation. The number-average molecular weight (Mn ) of fraction F1 (1265.8 Da), which was eluted first, was the highest, followed by those of fractions F2 (1028.6 Da), F3 (652.2 Da), F4 (562.2 Da) and F5 (469.6 Da). The total gas (mL g(-1) dry matter (DM)) and CH4 production decreased significantly (P fractions, but there were no significant (P > 0.05) differences between the CT fractions and control on DM degradation. However, the in vitro N disappearance decreased significantly (P fraction F1 (highest MW) compared with the control and other fractions (F2-F5). The inclusion of CT fraction F1 also significantly decreased (P fraction F1 but not by the control and other fractions (F2-F5). The CT fractions of different MWs from LLR could affect rumen fermentation and CH4 production, and the impact was more pronounced for the CT fraction with a higher MW. © 2014 Society of Chemical Industry.

  12. Characterization of chemical elements of fruits of Leucaena leucocephala in riverside areas of the Piracicaba River Basin, São Paulo, Brazil

    International Nuclear Information System (INIS)

    França, Elvis J.; Magalhães, Marcelo R.L. de; Ferreira, Fabiano S.; Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro; Silva, Bruno F.

    2017-01-01

    The species Leucaena leucocephala is present in several environments. Its fruit is widely used in cattle feed. However, it is classified as an invasive species, causing problems in the restoration of impacted areas. The Piracicaba River Basin is heavily affected by urbanization and industrialization, which shows the proliferation of this species. Considering the importance of this tree species for Brazil, the present study quantifies chemical elements in fruits of this species by applying Instrumental Neutronic Activation Analysis, method k 0 . Samples were collected in riverside areas of the Piracicaba Municipality, São Paulo, Brazil, at different periods (dry and rainy season). After collection, the samples were shattered and transferred to polyethylene capsules and irradiated with neutrons. Certified reference materials were used to evaluate the quality of the analytical procedure, all material was irradiated under a thermal neutron flux of 10 13 cm-2s-1 for 8 hours. Ni-Cr alloy was used for the monitoring of thermal neutron flux. High Resolution Range Spectrometry with HPG detectors was employed for the measurement of the induced radioactivity, allowing the quantification of the chemical elements. Compared with available results of chemical analysis of pods, the chemical elements Ca, K, Ba, Cr and Se presented high concentrations. We also quantified chemical elements of environmental relevance such as As, Hg, Br, Ce, Cs, Eu, Hf, La, Rb, Sb, Sc, Sm, Ta, Tb, Th and Yb, indicating the need for element dynamics studies in the environments occupied by this invasive species

  13. Efecto bioestimulante de Trichoderma harzianum Rifai en posturas de Leucaena, Cedro y Samán

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    Leonides Castellanos González

    2018-01-01

    Full Text Available El presente artículo evaluó el efecto bioestimulante de Trichoderma harzianum Rifai en la producción de postura de Leucaena leucocephala (Lam de Wit., Cedrela odorata L. y Albizia saman (Jacq. Merr. Se desarrollaron tres experimentos en condiciones de vivero, uno para cada especie. Se empleó un diseño completamente aleatorio con cuatro parcelas por tratamiento. En cada experimento los tratamientos fueron: Trichoderma harzianum a razón de 20 g.L-1, 40 g.L-1 y un testigo. Se evaluó el porcentaje de germinación y las variables morfométricas diámetro y altura del tallo, así como biomasa seca en raíz y parte aérea de la planta. Los tratamientos con Trichoderma no incrementaron el porcentaje de germinación en cedro, samán y leucaena. T. harzianum incrementó la altura, el número de hojas y la biomasa seca del área foliar en las plántulas de cedro, mientras que en leucaena y samán solo provocó incrementos del diámetro basal de las plántulas.

  14. Descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala (Lam de Wit cv. Cunningham: III. Influencia de la densidad y diversidad de la macrofauna asociada Litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala (Lam de Wit cv. Cunningham: III. Influence of density and diversity of the associated macrofauna

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    Saray Sánchez

    2010-03-01

    Full Text Available Con el objetivo de determinar la descomposición de la hojarasca en un sistema silvopastoril de Panicum maximum y Leucaena leucocephala y su relación con la densidad y la diversidad de la macrofauna asociada, se realizó este experimento en la EEPF «Indio Hatuey». Esta se determinó como la pérdida de biomasa a través del tiempo, con relación al peso inicial. Para el estudio de la dinámica de la descomposición se utilizó el método de bolsas de hojarasca (litter bags. Se escogieron al azar cuatro bolsas a los 30, 60, 90, 120, 150, 180 y 210 días de situadas en el pastizal. En cada fecha de recolección, a la hojarasca remanente de cada bolsa se le determinó la población de macrofauna (organismos con diámetro mayor que 2 mm mediante la separación manual, y se calculó el valor promedio de la densidad (individuos/m², así como la abundancia proporcional (% para cada taxón. Se utilizó el análisis de correlación y regresión para conocer la interrelación entre las variables y los modelos de mejor ajuste. De acuerdo con los resultados se concluye que las condiciones de humedad y temperatura que genera el árbol en este sistema, así como la calidad de su hojarasca, posibilitan la presencia de una diversa y estable fauna asociada a las bolsas, la cual influyó en el proceso de descomposición.The trial was conducted at the EEPF «Indio Hatuey» in order to determine the litter decomposition in a silvopastoral system of Panicum maximum and Leucaena leucocephala and its relation to the density and diversity of the associated macrofauna. It was determined as biomass loss through time, with regards to initial weight. For the study of the decomposition dynamics the litter bag method was used. Four bags were randomly chosen 30, 60, 90, 120, 150, 180 and 210 days after being placed in the pastureland. In each collection date, to the remnant litter of each bag, the macrofauna (organisms with diameter higher than 2 mm population was

  15. Biomass production of Prosopis species (mesquite), leucaena, and other leguminous trees grown under heat/drought stress

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.; Nash, P.

    1983-01-01

    Leguminous trees were examined for use on hot/arid lands in field trials in the Califronia Imperial Valley where July daily maximum temperatures are 42/sup 0/C (108/sup 0/F). Two field trials were carried out to rank 55 accessions in biomass per tree and to evaluate biomass production per unit area with four of the more productive accessions identified in earlier trials. The trial with 55 accessions compared Prosopis (mesquite) to widely recommended species for arid lands such as Leucaena leucocephala (K-8), Parkinsonia aculeata, and Prosopis tamarugo and to other drought adapted tree legume species of California/Arizona deserts such as Cercidium fluoridium and Olneya tesota. Prosopis selections were identified that had greater productivity than either Leucaena leucocephala (K-8) or Parkinsonia aculeata. The mean ovendry biomass per accession ranged from 0.2 kg/tree for Prosopis tamarugo to 29 kg/tree for P. alba (0166) when measured 2 years from germination in the greenhouse. Clones were obtained from trees in this trial which had 45-56 kg/tree (ovendry) in two seasons. The plots designed to measure biomass production per unit area were on a 1.5 m spacing and had productivities of 7, 11.2, 14.3, and 14.5 ovendry T ha/sup -1/ yr/sup -1/ for P. glandulosa var torreyana (0001), P. alba (0163), P. chilensis (0009), and P. alba (0039), respectively, when measured 2 years from germination in the greenhouse.

  16. Biomass production of Prosopis species (mesquite), Leucaena, and other leguminous trees grown under heat/drought stress

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Cannell, G.H.; Clark, P.R.; Osborn, J.F.; Nash, P.

    1983-09-01

    Leguminous trees were examined for use of hot/arid lands in field trials in the California Imperial Valley where July daily maximum temperatures are 42 degrees C (108 degrees F). Two field trials were carried out to rank 55 accessions in biomass per tree and to evaluate biomass production per unit area with four of the more productive accessions identified in earlier trials. The trial with 55 accessions compared Prosopis (mesquite) to widely recommended species for arid lands such as Leucaena leucocephala (K-8), Parkinsonia aculeata, and Prosopis tamarugo and to other drought adapted tree legume species of California/Arizona deserts such as Cercidium floridium and Olneya tesota. Prosopis selections were identified that had greater productivity than either Leucaena leucocephala (K-8) or Parkinsonia aculeata. The mean oven-dry biomass per accession ranged from 0.2 kg/tree for Prosospis tamarugo to 29 kg/tree for P. alba (0166) when measured 2 years from germination in the greenhouse. Clones were obtained from trees in this trial which had 45-56 kg/tree (oven-dry) in two seasons. The plots designed to measure biomass production per unit area were on a 1.5 m spacing and had productivities of 7, 11.2, 14.3, and 14.5 oven-dry T ha-1 yr-1 for P. glandulosa var torreyana (0001), P. alba (0163), P. chilensis (0009), and P. alba(0039), respectively, when measured 2 years from germination in the greenhouse. 30 references

  17. Ácidos grasos, fermentación ruminal y producción de metano, de forrajes de silvopasturas intensivas con Leucaena.

    Directory of Open Access Journals (Sweden)

    Esperanza Prieto-Manrique

    2016-06-01

    Full Text Available El objetivo del presente trabajo fue determinar el efecto de los forrajes sobre los ácidos grasos de cadena larga, fermentación ruminal y producción de metano de un sistema silvopastoril intensivo de Leucaena leucocephala. La investigación se desarrolló en el laboratorio NUTRILAB–GRICA, perteneciente a la Facultad de Ciencias Agrarias, de la Universidad de Antioquia, Medellín–Colombia, en julio del 2013. Se utilizó la técnica de producción de gas in vitro, utilizando como sustrato de fermentación las gramíneas (C. plectostachyus y/o M. maximus cv. Tanzania y leucaena (L. leucocephala, solas o en sus combinaciones, con una relación forraje:concentrado 70:30 y gramínea: leucaena 56:14, para un total de siete tratamientos. No se encontró efecto de los forrajes (p>0,05, sobre el contenido de ácido linoleico conjugado (ALC, C18:2 c9t11 o ruménico en la digesta. La inclusión de 14% de leucaena aumentó el contenido de ácido linoleico (C18:2 c9, 12 y linolénico (C18:3 c9, 12, 15 en el alimento y de transvaccénico (ATV, C18:1 t11, esteárico (C18:0, linoleico y linolénico en la digesta (p<0,05, y no afectó la cinética de fermentación, digestibilidad de la materia seca (MS, pH, total y proporción de ácidos grasos volátiles, ni redujo la producción de metano. Las gramíneas, C. plectostachyus y M. maximus, se comportaron similar en las variables evaluadas (p>0,05. Los sistemas silvopastoriles pueden ser una opción para aumentar los ácidos grasos benéficos en la leche.

  18. Evaluación de dos especies de Leucaena, asociadas a Brachiaria brizantha y Clitoria ternatea en un sistema silvopastoril de Nayarit, México: II. Producción y composición bromatológica de la biomasa Evaluation of two Leucaena species, associated to Brachiaria brizantha and Clitoria ternatea in a silvopastoral system from Nayarit, Mexico: II. Biomass production and bromatological composition

    Directory of Open Access Journals (Sweden)

    J Bugarín

    2009-12-01

    Full Text Available Con el objetivo de caracterizar la producción y la calidad nutricional de la biomasa en un sistema silvopastoril de la llanura costera norte del estado de Nayarit, México, se desarrolló la presente investigación. Los tratamientos fueron: 1 Leucaena leucocephala-B. brizantha (30:70; 2 Leucaena glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha-C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. Se estimó la producción de biomasa y se determinó: materia seca, cenizas, materia orgánica, proteína bruta, hemicelulosa y las fracciones de fibra ácido y neutro detergente. Los valores más bajos en cuanto a la producción de biomasa, a los seis meses de establecido el sistema, fueron para el testigo (0,78 t/ha, con diferencias significativas. A su vez, la combinación de las tres especies aportó los mejores resultados (1,64 y 1,69 t/ha para los tratamientos 3 y 4, respectivamente y a los nueve meses triplicaron la producción de biomasa. Hubo diferencias significativas en la composición bromatológica en todas las combinaciones evaluadas. No obstante, todas las especies mostraron características nutricionales adecuadas y constituyen una alternativa para los sistemas silvopastoriles tropicales en esta región.This study was conducted with the objective of characterizing the biomass production and nutritional quality in a silvopastoral system of the northern coastal plain of the Nayarit state, Mexico. The treatments were: 1 Leucaena leucocephala-B. brizantha (30:70; 2 Leucaena glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha- C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. The biomass production was estimated and the following indicators were determined: dry matter, ashes, organic matter, crude protein, hemicellulose and the fractions of acid and neutral detergent fiber. The lowest values regarding biomass production, six months after

  19. Modelos de crescimento resultantes da combinação e variações dos modelos de Chapman-Richards e Silva-Bailey aplicados em Leucaena leucocephala (Lam. de Wit.

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    Cícero Carlos Ramos de Brito

    2010-08-01

    Full Text Available O objetivo deste trabalho foi desenvolver novos modelos de crescimento para recursos florestais aplicados à leucena [Leucaena leucocephala (Lam. de Wit], tendo como base as hipóteses biológicas propostas por Chapman-Richards e Silva-Bailey. O experimento de leucena foi conduzido na Estação Experimental da Empresa Pernambucana de Pesquisa Agropecuária - IPA, Caruaru, PE. Foram utilizadas 544 árvores de leucena de um experimento com vinte remedições realizadas ao longo de 12 anos. Compararam-se novos modelos de crescimento resultantes da combinação e variações dos modelos de Chapman-Richards e Silva-Bailey, bem como outros comumente usados em recursos florestais. Para a seleção das equações, utilizaram-se o Índice de Ajuste (IA, o erro-padrão da estimativa e a distribuição gráfica dos resíduos. Os resultados indicaram que todos os modelos testados se ajustaram de maneira satisfatória aos dados, podendo ser utilizados para se estimar o crescimento em altura da leucena.

  20. Characterization of chemical elements of fruits of Leucaena leucocephala in riverside areas of the Piracicaba River Basin, São Paulo, Brazil; Caracterização de elementos químicos de frutos de Leucaena leucocephala em áreas ribeirinhas da Bacia do Rio Piracicaba, São Paulo, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    França, Elvis J.; Magalhães, Marcelo R.L. de; Ferreira, Fabiano S., E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: biologofabiano10@gmail.com [Centro de Ciência Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Fernandes, Elisabete A. de N.; Fonseca, Felipe Y.; Rodrigues, Vanessa S.; Cavalca, Isabel P.O.; Camilli, Leandro, E-mail: lis@cena.usp.br, E-mail: vsrodrigues89@gmail.com, E-mail: i-cavalcante@uol.com.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Silva, Bruno F., E-mail: brunodasilva1996@hotmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2017-07-01

    The species Leucaena leucocephala is present in several environments. Its fruit is widely used in cattle feed. However, it is classified as an invasive species, causing problems in the restoration of impacted areas. The Piracicaba River Basin is heavily affected by urbanization and industrialization, which shows the proliferation of this species. Considering the importance of this tree species for Brazil, the present study quantifies chemical elements in fruits of this species by applying Instrumental Neutronic Activation Analysis, method k{sup 0}. Samples were collected in riverside areas of the Piracicaba Municipality, São Paulo, Brazil, at different periods (dry and rainy season). After collection, the samples were shattered and transferred to polyethylene capsules and irradiated with neutrons. Certified reference materials were used to evaluate the quality of the analytical procedure, all material was irradiated under a thermal neutron flux of 10{sup 13} cm-2s-1 for 8 hours. Ni-Cr alloy was used for the monitoring of thermal neutron flux. High Resolution Range Spectrometry with HPG detectors was employed for the measurement of the induced radioactivity, allowing the quantification of the chemical elements. Compared with available results of chemical analysis of pods, the chemical elements Ca, K, Ba, Cr and Se presented high concentrations. We also quantified chemical elements of environmental relevance such as As, Hg, Br, Ce, Cs, Eu, Hf, La, Rb, Sb, Sc, Sm, Ta, Tb, Th and Yb, indicating the need for element dynamics studies in the environments occupied by this invasive species.

  1. Efeito da suplementação com feno de Leucena (Leucaena leucocephala (Lam de Wit durante a estação seca sobre o desenvolvimento ponderal de ovinos Effect of supplementation with Leucaena leucocephala hay during the dry season on the ponderal development sheep

    Directory of Open Access Journals (Sweden)

    Antônio Alves de Souza

    1999-01-01

    Full Text Available O objetivo deste experimento foi estudar o desempenho de borregos suplementados com dois níveis de feno de leucena (Leucaena leucocephala (Lam de Wit, durante a estação seca, em comparação com animais mantidos em pastagem exclusiva de capim-buffel (Cenchrus ciliaris, L ou em pastagem consorciada de capim-buffel com guandu (Cajanus cajan. Durante a estação das águas, foi determinado ainda o desempenho dos animais que foram mantidos em pastagem comum de capim-buffel, sem suplementação. Os seguintes tratamentos foram testados durante a estação seca: A - pasto de capim-buffel; B - pasto de capim-buffel consorciado com guandu; C - pasto de capim-buffel suplementado com feno de leucena (250 g/animal•d; e D - pasto de capim-buffel suplementado com feno de leucena (500 g/animal•d. Durante a estação seca, somente os borregos suplementados com o nível mais alto de feno de leucena (tratamento D apresentaram ganho diário de peso mais elevado que os animais mantidos em dieta exclusiva de pasto (tratamentos A e B. Na estação das águas, os animais que apresentaram melhor desempenho durante a estação seca passaram a apresentar ganho diário de peso inferior em relação aos dos demais tratamentos. Quando as duas estações foram consideradas em conjunto, a vantagem com a suplementação desapareceu e não houve diferenças entre tratamentos. O uso de feno de leucena para suplementação de borregos mantidos a pasto, durante a estação seca, é eficiente, desde que os animais estejam terminados e sejam abatidos ao final da estação.

  2. Estimating Apparent Nutrient Digestibility of Diets Containing Leucaena leucocephala or Moringa oleifera Leaf Meals for Growing Rabbits by Two Methods.

    Science.gov (United States)

    Safwat, A M; Sarmiento-Franco, L; Santos-Ricalde, R H; Nieves, D; Sandoval-Castro, C A

    2015-08-01

    This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM) or Moringa oleifera (MOLM) leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average) were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05) in feed, dry matter (DM), organic matter (OM), crude protein (CP), digestible energy, and crude fiber (CF) intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001), meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets.

  3. Study on Leucaena leocochepala seed during fermentation : sensory characteristic and changes on anti nutritional compounds and mimosine level

    Science.gov (United States)

    Nursiwi, A.; Ishartani, D.; Sari, AM; Nisyah, K.

    2018-01-01

    Lamtoro (Leucaena leucocephala) seed is one of the leguminosae which have high level of protein but it contains toxic compound such as mimosine and some anti nutritional compounds such as phitic acid and tannin. The objectives of the research was to investigate the sensory characteristic and the changes onanti nutritional compounds and mimosine level in Leucaena leucochepala seed during fermentation. Lamtoro tempeh processing was carried out by boiling the seed, crushing to separate the hull, soaking, boiling, and fermentation. The best concentration inoculum in lamtoro tempeh processing was determined by hedonic test. Fermentation was carried out in 36 hours and every 6 hours mimosine, tannin, and phitic acid content was analyzed. From hedonic test, inoculum concentration of 1% was used in lamtoro tempeh processing. During 36 hours fermentation, phytic acid content and mimosine content was decreased significantly, from 0.0558 % to 0.0453 % and from 0.00393 % to 0.00173 % respectively. Whereas tannin content was increased signifacantly, from 0.0822 % to 0.00173 %.

  4. Untitled

    African Journals Online (AJOL)

    seedlings of different NFT species and genotypes (b) of different NFT species and genotypes. (L.I. = grown in pots. (L.I. = Leucaena leucocephala; Leucaena leucocephala; Vertical bars =LSD,5%). Vertical bars = LSD, 5%). was no response to inoculation with TAL 169. significant differences between the two treatments.

  5. Effet de Leucaena leucocephala, des fientes de volaille ou du fumier de bovins sur la productivité du maïs cultivé sur "terre de barre" au sud Bénin

    Directory of Open Access Journals (Sweden)

    Mallouhi, N.

    1997-01-01

    Full Text Available Effect of Leucaena leucocephala, Poultry Manure or Cattle Manure on Maize Productivity on Feralitic Soil "terre de barre" in South Benin. Our work has consisted on the study of post-effect of Leucaen's prunings and poultry manure buried last year and also on the study of the direct effect of cattle manure and its interaction with Leucaen's pruning on maize productivity on feralitic soil "terre de barre". - The mixture of Leucaen's prunings and poultry manure had positive post-effect giving a yield of fresh ears and grains significantly higher (9 % to the reference and other treatments in the plots over the alley. - The supply of 5 t/ha of cattle manure appears insufficient. On the other hand the mixture of Leucaen's prunings and cattle manure gave the best results related to the soil's properties such as organic matter's content or total exchange capacity of the soil and also concerning the yields. In this case we notice that ail the results are significantly higher to the other treatments. These results emphasize the importance of a supply of organic matter's to the soil thereby fertilizing it in humus and mineral elements.

  6. Comportamiento ecofisiológico de Brachiaria decumbens en monocultivo y en asociación con Leucaena leucocephala Ecophysiological performance of Brachiaria decumbens in monocrop and in association with Leucaena leucocephala

    Directory of Open Access Journals (Sweden)

    A Rodríguez-Petit

    2008-09-01

    Full Text Available Con el objeto de estudiar las relaciones ecofisiológicas que determinan el crecimiento de B. decumbens en monocultivo (MO y asociada a L. leucocephala (AS, se realizaron evaluaciones de radiación fotosintéticamente activa (RFA, asimilación (A, conductancia estomática (Gs, transpiración (E, humedad relativa (HR, po­tencial hídrico de la hoja (Øh, diferencial de presión vapor (DPV e índice de área foliar (IAF en ambas condiciones (AS y MO, en una zona de bosque húmedo tropical; estas evaluaciones se hicieron a los 5, 10 y 22 días después del pastoreo en ambas condiciones. Los valores más positivos de Øh se encontraron en AS, al igual que los valores más bajos de RFA, con diferencias significativas (PIn order to study the ecophysiological relations that affect the growth of B. decumbens in monocrop (MO and associated with L. leucocephala (AS, evaluations of photosynthetic active radiation (PAR, assimilation (A stomatic conductance (Gs, transpiration (E, relative humidity (RH, water potential (Øh, differential of steam pressure (DSP and leaf area index (LAI were made in a tropical humid forest zone. The evaluations were made 5, 10 and 22 days after grazing under both conditions (MO and AS. The most positive values of Øh (P<0,05 were found in AS, as well as the lowest values of PAR (P<0,05 in all the evaluated dates. RH and DSP did not show differences (P 0,05. The gas exchange parameters (E, Gs and A showed significantly higher values in MO (P<0,05 in all dates. LAI was higher in MO after 10 and 22 days of evaluation. Due to the limitation of the photosynthetic capacity exerted by the light decrease on the grass, that PAR is concluded to be the most important factor that determine growth and development of B. decumbens in AS.

  7. Evaluación de dos especies de Leucaena, asociadas a Brachiaria brizantha y Clitoria ternatea en un sistema silvopastoril de Nayarit, México: I. Comportamiento agronómico Evaluation of two Leucaena species, associated to Brachiaria brizantha and Clitoria ternatea in a silvopastoral system from Nayarit, Mexico: I. Agronomic performance

    Directory of Open Access Journals (Sweden)

    J Bugarín

    2009-12-01

    Full Text Available Con el objetivo de evaluar el comportamiento agronómico de dos especies de Leucaena, asociadas a Brachiaria brizantha y Clitoria ternatea en un sistema silvopastoril en la llanura costera norte del estado de Nayarit, en México, se desarrolló la presente investigación. Se utilizó un diseño de bloques al azar con cuatro repeticiones por tratamiento (proporción de leguminosa:gramínea: 1 L. leucocephala-B. brizantha (30:70; 2 L. glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha- C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. Con una frecuencia mensual se midió el crecimiento de las especies arbóreas, además de la supervivencia y el comportamiento de la relación leguminosa:gramínea en el sistema. L. glauca mostró una mayor altura (66 cm y diámetro (0,98 cm cuando se combinó con brachiaria y clitoria, y L. leucocephala un mayor número de ramas (8,7 y altura (4,5 cm. En la sobrevivencia se observaron valores de 70 a 80% después de un año de implementado el sistema. De acuerdo con los resultados se concluye que la mezcla de las leguminosas arbóreas con C. ternatea y B. brizantha es una importante opción en las condiciones ecológicas del trópico seco mexicano.This study was conducted with the objective of evaluating the agronomic performance of two Leucaena species, associated to Brachiaria brizantha and Clitoria ternatea in a silvopastoral system in the northern coastal prairie of the Nayarit state, Mexico. A randomized block design was used with four repetitions per treatment (legume:grass proportion: 1 L. leucocephala-B. brizantha (30:70; 2 L. glauca-B. brizantha (30:70; 3 L. leucocephala-B. brizantha- C. ternatea (28:52:20; 4 L. glauca-B. brizantha-C. ternatea (28:52:20; 5 B. brizantha (100. Tree growth was measured on a monthly basis, in addition to survival and the performance of the legume:grass relationship in the system. L. glauca showed more height (66 cm and diameter

  8. Costos y beneficios de un sistema silvopastoril intensivo (sspi, con base en Leucaena leucocephala (Estudio de caso en el municipio de Tepalcatepec, Michoacán, México

    Directory of Open Access Journals (Sweden)

    J. M. González

    2013-01-01

    Full Text Available Se analizaron los costos en que se incurren y los beneficios económicos que se generan en un SSPi con base en Leucaena leucocephala, en terrenos de riego por gravedad, con el fin de evaluar la rentabilidad económica de las inversiones y hacer una comparación entre el SSPi y el sistema que tradicionalmente operaba o línea base (40% monocultivo de pasto Tanzania Panicum maximum, 30% de sorgo forrajero Sorghum vulgar bajo el sistema de corte y 30% de agostadero con pastos nativos. Complementando la alimentación del ganado suizo de doble propósito en el SSPi con pulido de arroz a razón de 1.50 kg diarios por vaca durante la ordeña; y en la línea base se utilizó 3.50 kg de alimento comercial diario por vaca ordeñada. Resultando, para el SSPi, una TIR del 13.30% y el VAN al 10%, un saldo positivo de $2’202,170 (pesos mexicanos y en la situación inicial o línea base se obtuvo una TIR del 0.70% y el VAN al 10% resultó negativo, con $-4’717,022 (pesos mexicanos. El SSPi incrementó de manera importante la productividad y la rentabilidad del rancho haciéndolo lucrativo, ya que con el sistema tradicional no era rentable económicamente.

  9. Characterization of Leucaena (Leucaena leucephala) oil by direct analysis in real time (DART) ion source and gas chromatography; Caracterización del aceite de Leucaena (Leucaena leucocephala) por análisis directo en tiempo real (DART) y cromatografía de gases

    Energy Technology Data Exchange (ETDEWEB)

    Alam, M.; Alandis, N.M.; Sharmin, E.; Ahmad, N.; Alrayes, B.F.; Ali, D.

    2017-07-01

    For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaena (Leucaena leucephala) oil [LUCO], an unexplored nontraditional non-medicinal plant belonging to the family Fabaceae. LUCO was converted to fatty acid methyl esters (FAMEs). We analyzed the triacylglycerols (TAGs) of pure LUCO and their FAMEs by time-of-flight mass spectrometry (TOF-MS) followed by multivariate analysis for discrimination among the FAMEs. Our investigations for the analysis of LUCO samples represent noble features of glycerides. A new type of ion source, coupled with high-resolution TOF-MS was applied for the comprehensive analysis of triacylglycerols. The composition of fatty acid based LUCO oil was studied using Gas Chromatography (GC-FID). The major fatty acid components of LUCO oil are linoleic acid (52.08%) oleic acid (21.26%), palmitic acid (7.91%) and stearic acid (6.01%). A metal analysis in LUCO was done by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The structural elucidation and thermal stability of LUCO were studied by FT-IR, 1H NMR, 13C NMR spectroscopic techniques and TGA-DSC, respectively. We also measured the cytotoxicity of LUCO [Spanish] Se presenta por primera vez la caracterización de triacilgliceroles y ácidos grasos del aceite de Leucaena (Leucaena leucephala) [LUCO], una planta no medicinal, no tradicional y no explorada, perteneciente a la familia Fabaceae. Se analizaron triacilgliceroles (TAGs) de LUCO y sus FAMEs por espectrometría de masas de tiempo de vuelo (TOF-MS) seguido de análisis multivariante para discriminación entre los FAME. Nuestras investigaciones para el análisis de muestras de LUCO presentaron características propias de los glicéridos. Un nuevo tipo de fuente de iones, junto con alta resolución TOF-MS se aplicó para el análisis exhaustivo de triacilgliceroles. La composición de aceite de LUCO basado en ácidos grasos se estudió usando Cromatografía de Gas (GC-FID). Los principales

  10. Respuesta de Leucaena leucocephala cv. Perú a la aplicación de diferentes dosis de MicoFert agrícola

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    L Ojeda

    Full Text Available Se realizó una investigación en la Empresa Pecuaria El Tablón (Cumanayagua, provincia Cienfuegos, Cuba, con el objetivo de evaluar el efecto que ejerce la aplicación de diferentes dosis de MicoFert agrícola sobre la producción de materia seca (MS y el contenido de fósforo foliar en Leucaena leucocephala cv. Perú. El diseño fue de bloques al azar, con seis tratamientos y tres réplicas. Los tratamientos estuvieron constituidos por cuatro dosis de MicoFert (250, 500, 750 y 1 000 g/m-1, una variante a razón de 25 kg de N ha-1, y el control. El experimento tuvo una duración de dos años; se realizaron cuatro cortes por año, con una frecuencia de 90 días, a una altura de 25 cm sobre el suelo. La aplicación de MicoFert agrícola incrementó el rendimiento de MS entre 13 y 40 %, de forma proporcional a las dosis aplicadas, respecto al control. El rendimiento más alto de MS (18,44 t ha-1 se obtuvo con la aplicación de nitrógeno, y difirió significativamente del resto de los tratamientos. Fue evidente el efecto que ejerció la inoculación con el biofertilizante en el contenido de fósforo foliar, el cual mostró diferencias significativas entre las variantes con MicoFert y el control. La colonización de raicillas por los hongos micorrízicos arbusculares (HMA fue proporcional al incremento de las dosis de biofertilizante, con valores de 34, 38, 44 y 49 %, respectivamente. La fertilización con nitrógeno y el control presentaron 28 y 26 % de colonización micorrízica, lo que indicó la presencia de HMA nativos.

  11. Capacidad de recuperación de 23 accesiones de Leucaena spp. después de la poda Recovery capacity of 23 Leucaena spp. accessions after pruning

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    Hilda B Wencomo

    2011-03-01

    Full Text Available Se evaluaron 23 accesiones de Leucaena spp. durante dos años, con el objetivo de conocer la variabilidad existente en la población en cuanto a la capacidad de recuperación después de la poda. Cuando las plantas sobrepasaban los 2 m, se realizó la poda de uniformidad a un 1 m de altura sobre el nivel del suelo. Las mediciones fueron: el grosor del tallo, el número de rebrotes y su longitud con una frecuencia semanal, a partir de lo cual se calculó la velocidad de crecimiento de cada accesión; además se determinó el rendimiento. El análisis de componentes principales, el de conglomerados y el de regresión lineal simple se realizaron a través del programa estadístico SPSS versión 11.5 para Microsoft Windows®. Se observó variabilidad en los indicadores evaluados (86,11% acumulado en la componente y todos contribuyeron a su explicación. A su vez, el análisis de conglomerados permitió la formación de tres grupos. Se concluye que todas las accesiones presentaron capacidad de recuperación después de la poda, con diferencias entre ellas. Las accesiones Leucaena leucocephala cv. Cunningham, cv. Perú, CIAT-9119, CIAT-9438, CIAT-751, CIAT-7988, CIAT-7384, CIAT-7929, CIAT-17480, cv. Ipil-Ipil y cv. CNIA-250; L. lanceolata CIAT-17255 y CIAT-17501 y L. diversifolia CIAT-17270 fueron las de mayor capacidad de recuperación. Por ello se recomienda, en futuras investigaciones relacionadas con la caracterización, evaluación y selección de estas especies, realizar estudios que incluyan su persistencia en el tiempo bajo condiciones de poda, así como su empleo en el fomento de nuevos sistemas silvopastoriles.Twenty three Leucaena spp. accessions were evaluated for two years, in order to know the variability existing in the population regarding the recovery capacity after pruning. When the plants were higher than 2 m, the uniformity pruning was made at 1 m above the soil level. The measurements were: stem diameter, number of regrowths and

  12. Efecto de la suplementación con residuos de destilería del maíz en el comportamiento de novillas en una asociación de gramínea y leucaena Effect of supplementation with corn distillery residues on the performance of heifers in an association of grass and leucaena

    Directory of Open Access Journals (Sweden)

    Tania Sánchez

    2010-09-01

    Full Text Available El objetivo del presente trabajo fue evaluar el efecto de la suplementación con residuos de destilería del maíz en el comportamiento de novillas, en una asociación de gramínea y leucaena. El estudio se realizó en un área de la Estación Experimental "Indio Hatuey", en el municipio de Perico, provincia de Matanzas, Cuba. La especie de pasto predominante fue Panicum maximum cv. Likoni y como leguminosa Leucaena leucocephala. Se estudiaron 18 novillas, distribuidas en un diseño completamente aleatorizado en tres grupos de seis animales; el grupo control no recibió suplementación (A y los otros dos grupos se suplementaron con residuos de destilería del maíz en un 10% (B y 20% (C de los requerimientos de proteína con relación al peso vivo. Se determinó la composición química, la disponibilidad de materia seca, la ganancia de peso vivo, la infestaci��n parasitaria y el hematocrito. Al analizar las ganancias diarias por tratamiento se encontraron diferencias significativas (PThe objective of this work was to evaluate the effect of supplementation with corn distillery residues on the performance of heifers in an association of grass and leucaena. The study was conducted in an area of the Experimental Station "Indio Hatuey" , Perico municipality, Matanzas province, Cuba. The prevailing pasture species was Panicum maximum cv. Likoni and as legume, Leucaena leucocephala. Eighteen heifers, distributed in a completely randomized design in three groups of six animals, were used; the control group did not receive supplementation (A, and the other two groups were supplemented with corn distillery residues in 10% (B and 20% (C of the protein requirements with regards to live weight. The chemical composition, dry matter availability, live weight gain, parasite infestation and hematocrit were determined. When analyzing the daily gain per treatments, significant differences (P<0,05 were found and the highest values were obtained in treatment C

  13. Farinha de folha de leucena (Leucaena leucocephala Lam. de wit como fonte de proteína para juvenis de tambaqui (Colossoma macropomum CUVIER, 1818 Leucaena leaf flour (Leucaena leucocephala Lam. of wit as a protein source for juveniles of tambaqui (Colossoma macropomum Cuvier, 1818

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    Geraldo Pereira Junior

    2013-06-01

    Full Text Available O tambaqui (Colossoma macropomum é um peixe onívoro, natural da bacia amazônica, que possui elevado valor comercial. Características de rusticidade e desempenho produtivo destacam esta espécie para criação em cativeiro. Contudo, em criações comerciais de peixes, os custos com alimentação podem corresponder de 60 a 80% dos custos totais de produção, sendo a proteína o nutriente mais caro da dieta. O objetivo deste trabalho foi avaliar o desempenho produtivo de juvenis de tambaqui alimentados com rações contendo farinha de folha de leucena como fonte protéica. 240 juvenis foram distribuídos em 12 aquários experimentais (350 L, em um delineamento experimental inteiramente casualizado com quatro tratamentos (0%, 8%, 16%, 24% de inclusão de farinha de folha de leucena na ração e três repetições. Foram determinados o ganho de peso, conversão alimentar aparente, taxa de crescimento específico, taxa de eficiência protéica e custo de produção do quilograma de peso vivo ganho. Para as variáveis estudadas, não houve diferença significativa (p>0,05 entre os tratamentos, indicando que é possível incluir até 24% de farinha de folha de leucena em rações para juvenis de tambaqui, sem comprometimento das variáveis estudadas, embora a substituição não tenha representado redução no custo de produção do quilograma de peixe.The tambaqui (Colossoma macropomum is an omnivorous fish native to the Amazon basin, which has high commercial value. Characteristics of rusticity and desirable growth in farming highlight this species for breeding in captivity. However, in commercial fish breeding, feed costs may represent 60-80% of total costs of production, being the protein the most expensive nutrient in the diet. The objective of this study was to evaluate the growth of juvenile tambaqui fed with diets containing leucaena leaf flour as protein source. A total of 240 juveniles were distributed in 12 experimental aquaria (350 L in

  14. Fixação do N2 em leucena (Leucaena leucocephala em solo da região semi-árida brasileira submetido à salinização

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    F. G. Carvalho

    1999-06-01

    Full Text Available Com a finalidade de avaliar a tolerância de rhizobium loti em Leucaena leucocephala cv K8, submetida a níveis crescentes de salinidade, realizou-se um experimento em casa de vegetação, usando-se um Podzólico Vermelho-Amarelo textura franco-arenosa, coletado em Serra Talhada (PE. O experimento obedeceu ao arranjo fatorial 5 x 4, no delineamento em blocos ao acaso, com 3 repetições. Foram usados 5 níveis de salinidade do solo (C.E. = 1,5; 6,6; 10,1; 12,8 e 14,4 dS m-1 e 2 tratamentos inoculados (NFB 494 e SEMIA 6069, fertilização nitrogenada com 200 mg kg-1 de N (NH4NO3, e o controle sem inoculação e sem adubação nitrogenada. O incremento dos níveis crescentes de salinidade reduziu a nodulação (número e massa de nódulos, o rendimento de matéria seca e a acumulação de N na parte aérea. O tratamento com fertilização nitrogenada inibiu totalmente a nodulação em leucena, em todos os níveis de salinidade; contudo, promoveu melhores rendimentos na acumulação de N e na produção de matéria seca. Observou-se resposta significativa das plantas inoculadas com a estirpe SEMIA 6069, em todas as características avaliadas, superando os resultados obtidos com o isolado NFB 494.

  15. The Germination of Some Species Tropical Legume Seeds

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    Eko Poetri

    2005-09-01

    Full Text Available A study to evaluate the seed germination of Leucaena pallida under climatic and soil conditions in Palu was conducted in village of Taipa, Sub district of North Palu, District of Palu. To compare with other species of legume trees however, this study involved Leucaena leucocephala cv Tarramba, Leucaena leucocephala cv Gumph and Gliricidia maculata. This experiment used completely randomized design with species of tropical tree legumes as treatment.  Each treatment was replicated five times.  Each experimental unit consisted of one tray (size 12.5 x 25 cm and planted by 20 seed.  Each tray was filled with soil while the seeds were planted one cm deep.  All seeds were immersed in warm water (600C for five minutes before planted.  The base of the trays were drilled to create some holes for water to drain out.  The trays were sprayed twice daily (07.00 am and 03.00 pm to keep the soil to be moist using a very smooth sprayer.  The variables recorded included the initiation time of germination, the range time of germination and the percentage of seed germination.  The data obtained were analyses using the Minitab 11. Least significance difference was used to test for possible differences between treatment means. The result revealed that initiation time of germination and the range of germination were not varied (P>0.05 among the seeds tested. The initiation time of germination ranged between 9 to 12 d after sowing.  Gliricidia maculata seed has the shortest period to germinate (12-16 d after sowing, meanwhile Leucaena leucocephala cv. Tarramba appear to be the longest (9-17 d after sowing. The highest seed viability was 60% in Leucaena leucocephala, cv Gump while the lowest was found in Gliricidia maculata (29%. In addition, both Leucaena pallida and Leucaena leucocephala cv Tarramba had medium seed germination (40% and 53% respectively. (Animal Production 7(3: 156-160 (2005Key Words: Seed, Germination, Tropical Leguminous

  16. Effects of sulfur and phosphorus application on the growth, biomass yield and fuel properties of leucaena (Leucaena leucocephala (Lam. de Wit. as bioenergy crop on sandy infertile soil

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    Songyos Chotchutima

    2016-01-01

    Full Text Available A field experiment was conducted to determine the effect of Sulfur (S and Phosphorus (P fertilizer on the growth, biomass production and wood quality of leucaena for use as a bioenergy crop at the Buriram Livestock Research and Testing Station, Pakham, Buriram province, Thailand during 2011–2013. The experiment was arranged in a split plot design with two rates of S fertilizer (0 and 187.5 kg/ha as a main plot and five rates of P (0, 93.75, 187.5, 375 and 750 kg/ha as a sub-plot, with four replications. The results showed that the plant height, stem diameter, total woody stem and biomass yield of leucaena were significantly increased by the application of S, while the leaf yield was not influenced by S addition. The total woody stem and biomass yield were also proportionately greatest with the maximum rate of P (750 kg/ha application. The addition of S did not result in any significant differences in fuel properties, while the maximum rate of P application also showed the best fuel properties among the several rates of P, especially with low Mg and ash contents compared with the control (0 kg/ha.

  17. Nutritional Characteristics of Important Dwarf Shrubs and Value of Leucaena leueocephala seeds as Protein Supplement for Goats in Marsabit District, Kenya

    International Nuclear Information System (INIS)

    Kuria, S.G; Karue, C.N

    1999-01-01

    A study on the nutritional characteristics of Indigofera spinosa and Duosperma eremophilum dwarf shrubs was carried out in Southwest Marsabit district of Kenya to establish the digestibility intake by goats and their chemical composition for management purposes. The value of Leucaena leucocephala seeds as protein supplement for goats was also tested where three levels, 0 (control), 50 and 100 g/goat/day were used. Intake and digestibility of the shrubs were assessed by difference and conventional methods respectively. Proximate analysis and Van Soest fibre analysis were done for chemical composition. Goats on l. spinosa had 330+ or -34. 5 g/day Dry Matter Intake (DMI) while those on D. eremophilum had 175+or-89.0 g/day. Dry Matter of l. spinosa was 40.3+or-2.9 % digestible while that of D. eremophilum was 45.0+or-6.6 % digestible. Indigofera spinosa contained 8.8 % Crude Protein (CP), 55.4 % Neutral Detergent Fibre (NDF) and 4.1 KCal/gDM energy compared to 7.6 % CP, 29.3 % Neutral Detergent Fibre (NDP) and 3.1 KCal/gDM energy for D. eremophililum. In reference to the controls, DMI increased by 124g and 55g for D. eremophilum and I. spinosa respectively for every 50g increase in L. lecocephala seeds for l. spinosa. From the results it was concluded that in terms of intake, digestibility and CP, both shrubs are medium quality. Leucaena leucocephala seeds are rich in CP (26.0%) and increased both DMI and DMD for the shrubs. It is thus suitable for use as protein supplement in small ruminant feeding especially during the dry season when it will increase intake and digestibility of the shrubs

  18. Caracterización cultural y morfológica e identificación de diez aislamientos de Fusarium procedentes de semillas de Leucaena leucocephala cv. Perú almacenadas Cultural and morphological characterization and identification of ten Fusarium isolates from stored Leucaena leucocephala cv. Peru seeds

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    J. C Lezcano

    2012-06-01

    Full Text Available El objetivo de este trabajo fue caracterizar cultural y morfológicamente diez aislamientos de Fusarium, obtenidos de semillas de L. leucocephala cv. Perú almacenadas, con vistas a su clasificación taxonómica. Sus cultivos puros se conservaron en tubos Eppendorf con medio Agar Papa y Dextrosa (APD, en cámara fría a 10°C. La siembra de cada aislamiento se realizó en tres placas Petri, esterilizadas, de 9 cm de diámetro; estas contenían, separadamente, los medios APD y Agar Papa Sacarosa (APS, que constituyeron las réplicas; se colocó en su centro un disco micelial de 7 mm de diámetro, procedente de cultivos con 10-15 días de edad, sembrados también en dichos medios. Posteriormente, las placas se sellaron con papel parafinado y se incubaron durante diez días a 25°C, con alternancia de 8 h de luz/16 h de oscuridad, o a oscuridad constante. Las variables culturales medidas fueron: el color de la colonia en el anverso y el reverso, la textura y el crecimiento lineal y aéreo; y como morfológicas se evaluaron: el tamaño, la forma y el color de las estructuras vegetativas y reproductivas que aparecieron en los cultivos. Se utilizó un diseño completamente aleatorizado y los datos se procesaron estadísticamente a través de un análisis descriptivo. Para la identificación de los hongos se utilizaron diferentes claves taxonómicas. Los aislamientos 10, 18 y 29 se correspondieron con las características descritas en la literatura científica para la especie Fusarium oxysporum Schlecht; el 17, el 28 y el 30, con Fusarium sambucinum Fuckel; el 27, con Fusarium semitectum Berk & Rav.; el 25 y el 26, con Fusarium incarnatum (Rob Sacc, y el 31, con Fusarium chlamydosporum Wollenw & Reinking, lo que permitió la identificación de cinco especies de Fusarium asociadas a las simientes almacenadas.The objective of this work was to characterize cultural and morphologically ten Fusarium isolates, obtained from stored Leucaena leucocephala cv

  19. Variación interespecífica de la calidad nutricional de diecisiete accesiones de Leucaena

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    D. E. García

    2008-01-01

    Full Text Available Se realizó un experimento para evaluar, mediante el análisis de componentes principales (ACP, la variabilidad de la composición nutricional del follaje de diecisiete accesiones del género Leucaena (8 L. leucocephala, 5 L. lanceolata, 2 L. diversifolia, 1 L. glauca y 1 L. esculenta establecidas en Matanzas, Cuba, en condiciones tropicales y suelo Ferralítico Rojo Lixiviado. Se determinó el perfil bromatológico, los niveles de metabolitos secundarios y la degradabilidad ruminal. Mediante el ACP se formaron tres componentes y se extrajo un porcentaje de varianza intermedio (64.83. Los indicadores que explicaron mejor las variaciones entre las accesiones fueron la fracción proteica (PC y PV, la lignina, los compuestos polifenólicos (FT, TPP, TC, los fitatos y la degradabilidad ruminal (DMS, DPC, DFDN. Sin embargo, los niveles de MS, fracción fibrosa (FDN, FDA, FC, celulosa, mimosina y minerales presentaron variaciones menos importantes. Se identificaron tres grupos variabilicon características nutricionales diferenciadas. Aunque todas las accesiones presentaron buena composición proximal, las accesiones de L. diversifolia y L. esculenta presentaron mayor concentración de metabolitos secundarios y menor degradabilidad ruminal. En todos los casos la degradación de la MS, PC y FDN se vio afectada por los contenidos de polifenoles y fitatos. Las accesiones de L. leucocephala (LPIII-187, IH- 164, IH-449, IH-1069, IH-1140, Ecotec, IRI- 3164, IRI-3219, L. lanceolata (CIAT-17223, CIAT-17501, CIAT-17252, CIAT-17255, CIAT-17256 y L. glauca presentaron los mejores resultados

  20. Intestinal digestibility of enriched-protein fodders measured by ...

    African Journals Online (AJOL)

    Ruminal, intestinal and total tract digestibility of dry matter (DM) and crude protein (CP) of leucaena (Leucaena leucocephala), Madras thorn (Pithecellobium dulce) and moringa (Moringa oleifera) fodders were measured in this study, using nylon bag and mobile bag techniques. Three cattle were fitted with permanent ...

  1. Leucaena sp. recombinant cinnamyl alcohol dehydrogenase: purification and physicochemical characterization.

    Science.gov (United States)

    Patel, Parth; Gupta, Neha; Gaikwad, Sushama; Agrawal, Dinesh C; Khan, Bashir M

    2014-02-01

    Cinnamyl alcohol dehydrogenase is a broad substrate specificity enzyme catalyzing the final step in monolignol biosynthesis, leading to lignin formation in plants. Here, we report characterization of a recombinant CAD homologue (LlCAD2) isolated from Leucaena leucocephala. LlCAD2 is 80 kDa homo-dimer associated with non-covalent interactions, having substrate preference toward sinapaldehyde with Kcat/Km of 11.6×10(6) (M(-1) s(-1)), and a possible involvement of histidine at the active site. The enzyme remains stable up to 40 °C, with the deactivation rate constant (Kd(*)) and half-life (t1/2) of 0.002 and 5h, respectively. LlCAD2 showed optimal activity at pH 6.5 and 9 for reduction and oxidation reactions, respectively, and was stable between pH 7 and 9, with the deactivation rate constant (Kd(*)) and half-life (t1/2) of 7.5×10(-4) and 15 h, respectively. It is a Zn-metalloenzyme with 4 Zn(2+) per dimer, however, was inhibited in presence of externally supplemented Zn(2+) ions. The enzyme was resistant to osmolytes, reducing agents and non-ionic detergents. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Growth of seedlings of pigeon pea (Cajanus cajan (l. millsp, wand riverhemp (Sesbania virgata (cav. pers., and lead tree (Leucaena leucocephala (lam. de wit in an arsenic-contaminated soil

    Directory of Open Access Journals (Sweden)

    Luiz Eduardo Dias

    2010-06-01

    Full Text Available Phytoremediation strategies utilize plants to decontaminate or immobilize soil pollutants. Among soil pollutants, metalloid As is considered a primary concern as a toxic element to organisms. Arsenic concentrations in the soil result from anthropogenic activities such as: the use of pesticides (herbicides and fungicides; some fertilizers; Au, Pb, Cu and Ni mining; Fe and steel production; coal combustion; and as a bi-product during natural gas extraction. This study evaluated the potential of pigeon pea (Cajanus cajan, wand riverhemp (Sesbania virgata, and lead tree (Leucaena leucocephala as phytoremediators of soils polluted by As. Soil samples were placed in plastic pots, incubated with different As doses (0; 50; 100 and 200 mg dm-3 and then sown with seeds of the three species. Thirty (pigeon pea and 90 days after sowing, the plants were evaluated for height, collar diameter and dry matter of young, intermediate and basal leaves, stems and roots. Arsenic concentration was determined in different aged leaves, stems and roots to establish the translocation index (TI between the plant root system and aerial plant components and the bioconcentration factors (BF. The evaluated species showed distinct characteristics regarding As tolerance, since the lead tree and wand riverhemp were significantly more tolerant than pigeon pea. The high As levels found in wand riverhemp roots suggest the existence of an efficient accumulation and compartmentalization mechanism in order to reduce As translocation to shoot tissues. Pigeon pea is a sensitive species and could serve as a potential bioindicator plant, whereas the other two species have potential for phytoremediation programs in As polluted areas. However, further studies are needed with longer exposure times in actual field conditions to reach definite conclusions on relative phytoremediation potentials.A fitorremediação é uma estratégia que utiliza plantas para descontaminar ou imobilizar poluentes

  3. Microbial activity in soil cultivated with different summer legumes in coffee crop

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-02-01

    Full Text Available A field experiment was conducted for ten years in a sandy soil in the north part of the Paraná State, Brazil. The soil samples were collected at 0-10 cm depth, both under the coffee canopy and in the inter row space between the coffee plants, in the following treatments: Control, Leucaena leucocephala, Crotalaria spectabilis, Crotalaria breviflora, Mucuna pruriens, Mucuna deeringiana, Arachis hypogaea and Vigna unguiculata. The legume crops influenced the microbial activity, both under the coffee canopy and in the inter row space. The cultivation of Leucaena leucocephala increased the microbial biomass C, N and P. Although L. leucocephala and Arachis hypogaea provided higher microbial biomass, the qCO2 decreased by up to 50% under the coffee canopy and by about 25% in the inter row space. The soil microbial biomass was enriched in N and P due to green manure residue addition.

  4. Preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, formicidae a diferentes espécies florestais, em condições de laboratório

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    Otávio Filho Peres

    2002-01-01

    Full Text Available It was evaluated the cutting ant preference of Atta sexdens rubropilosa Forel, 1908, to native and exotic forest tree species, in laboratory conditions. The most preferred species were: gmelina ( Gmelina arborea, leucaena (Leucaena leucocephala, caesalpinia (Caesalpinia ferrea, albizzia (Albizia lebbeck and enterolobium (Enterolobium contortisiliquum and the less preferred ones were: eucalypt (Eucalyptus grandis, jequitiba (Cariniana strellensis and guazuma (Guazuma tomentosa .

  5. Evaluating the performance of Leucaena accessions for agroforestry ...

    African Journals Online (AJOL)

    The performance of Leucaena accessions on acid soils in eastern coast Tanzania for agroforestry was evaluated for three years. Plant tree parameters assessed were fodder yield and plant stem height, stem girth, the number of total branches and poles production. Also, Leucaena psyllid, a common pest threatening the ...

  6. Leucaena 2: the tree that defies the woodcutter

    Energy Technology Data Exchange (ETDEWEB)

    Benge, M D

    1981-07-01

    This article emphasises Leucaena's ability to obtain nutrients from soil strata that are not accessible to most other plants by means of its deep-growing root system. Surrounding the roots of Leucaena are masses of mychorrhizae that can metabolise unavailable phosphorous and other minerals which are then slowly released to the plant. In addition, symbiotic nitrogen-fixing bacteria fix nitrogen from the air. The plant then transfers minerals and nitrogen to its leaves. In one system of upland farming, Leucaena is intercropped with root crops and is cut and applied to the intercropped annual crops as an organic mulch, providing fertilizer that the marginal farmer could not otherwise afford.

  7. Evaluation of herbicides for use in transplanting leucaena leucocephala and prosopis alba on semi-arid lands without irrigation

    Energy Technology Data Exchange (ETDEWEB)

    Felker, P.; Smith, D.; Smith, M.; Bingham, R.L.; Reyes, I.

    1984-01-01

    Five herbicides were applied to plots at 2 rates in April 1982, and 3-month old seedlings planted 2 days later. Basal diameter was measured after 110 days and converted to dry weight using published equations. Percent weed cover was recorded 45, 75, and 105 days after planting. All herbicides increased survival over untreated controls. The greatest biomass production of both species was obtained with oryzalin treatment at 2.8 kg/ha active ingredient, which increased production 4-5X compared with control plots. Oryzalin was second to napropamide (2.24 kg/ha active ingredient) in grass control and equal to oxyfluorfen (1.12 kg/ha active ingredient) in forb control, oxyfluorfen at this rate also gave the second best biomass production. Oryzalin increased survival from 71 to 87% for Leucaena and from 81-94% for Prosopis, and is considered to be the best herbicide tested, followed by oxyfluorfen and metolachlor. Alachlor was considered to be too short-lived and napropamide too expensive.

  8. Biomass accumulation and chemical composition of Massai grass intercropped with forage legumes on an integrated crop-livestock-forest system

    Directory of Open Access Journals (Sweden)

    Tatiana da Costa Moreno Gama

    2014-06-01

    Full Text Available The objective was to evaluate the use of woody legumes (Albizia lebbeck, Cratylia argentea, Dipteryx Allata (Baru, a Leucaena hybrid (L. leucocephala + L. diversifolia, and Leucaena leucocephalacv. Cunningham and herbaceous legumes (Arachis pintoi intercropped with Panicum maximum cv. Massai, simultaneously implanted in a maize crop. The study made use of a randomized block experimental design with four replications. Assessments of biomass accumulation and forage nutritional value were made after the maize harvest, between June 2008 and October 2010. It was found that the residues of maize provided better growing conditions for Massai grass during the dry season. L. leucocephala cv. Cunningham and the Leucaena hybrid had the highest accumulation of all forage legumes evaluated, and provided the best nutritional value of all the arrangements tested. Of all woody legumes tested in this system, Leucaena was considered feasible for intercropping with Massai grass. The intercrop of perennial woody Baru with maize is not recommended. Albizia lebbeck and Cratylia argentea require further study, especially the yield assessment at different cutting intervals and cutting heights. Arachis pintoi had a low participation in the intercropping, showing greater performance over time, indicating slow thriving in this experimental condition.

  9. Microbial Biomass Changes during Decomposition of Plant Residues in a Lixisol

    Directory of Open Access Journals (Sweden)

    Kachaka, SK.

    2003-01-01

    Full Text Available A lixisol was amended with four different alley cropping species: Senna siamea, Leucaena leucocephala, Dactyladenia barteri and Flemingia macrophylla. Soil samples were incubated for 140 days at 25 °C and the soil microbial biomass was determined by the ninhydrin extraction method along the incubation period. The soil microbial biomass values ranged between 80 and 600 mg.kg-1 and followed, in all cases, the decreasing order: Leucaena> Senna> Flemingia> Dactyladenia.

  10. Chemical Characteristics of Six Woody Species for Alley Cropping

    Directory of Open Access Journals (Sweden)

    Mosango, M.

    1999-01-01

    Full Text Available Leaves of six woody species (Leguminosae for alley cropping have been chemically analysed in order to evaluate their potentiality in the restoration of soil fertility. These species are : Acacia mangium, Cajanus cajan, Flemingia grahamiana, F. macrophylla, Leucaena leucocephala and Sesbania sesban. Nitrogen, carbon, cellulose, hemicellulose, lignin, active fraction and ash contents were determined as well as C/N and L/N ratios. AH these species appear to be rich in N and C. Fiber contents (cellulose, hemicellulose and lignin are globally low but variable from one species to another. C/N and L/N ratios are globally low. Among these species, Leucaena leucocephala and Senna spectabilis show the lowest C/N and LIN ratios. Such low values of C/N and L/N are normally found in species with rapid decomposition of organic matter.

  11. Browse Title Index

    African Journals Online (AJOL)

    Items 1 - 44 of 44 ... Soil Organic matter, NPK and yam yields, Abstract ... Vol 3, No 2 (2007), Countrywide distribution of fauna associated with the cassava ... of Leucaena leucocephala tree management on maize/cowpea performances in a ferric ...

  12. Browses (legume-legume mixture) as dry season feed ...

    African Journals Online (AJOL)

    Increasing competition between man and animals(monogasters, polygasters, microlivestock and wild/feral) for high quality feed(proteinaceous and carbonaceous concentrate) excessive pressure on land from urbanisation , hence the need of multipurpose browse-legumes (Leucaena leucocephala, Gliricidia sepium and ...

  13. Utilization of nitrogen fixing trees

    Energy Technology Data Exchange (ETDEWEB)

    Brewbaker, J.L.; Beldt, R. van den; MacDicken, K.; Budowski, G.; Kass, D.C.L.; Russo, R.O.; Escalante, G.; Herrera, R.; Aranguren, J.; Arkcoll, D.B.; Doebereinger, J. (cord.)

    1983-01-01

    Six papers from the symposium are noted. Brewbaker, J.L., Beldt, R. van den, MacDicken, K. Fuelwood uses and properties of nitrogen-fixing trees, pp 193-204, (Refs. 15). Includes a list of 35 nitrogen-fixing trees of high fuelwood value. Budowski, G.; Kass, D.C.L.; Russo, R.O. Leguminous trees for shade, pp 205-222, (Refs. 68). Escalante, G., Herrera, R., Aranguren, J.; Nitrogen fixation in shade trees (Erythrina poeppigiana) in cocoa plantations in northern Venezuela, pp 223-230, (Refs. 13). Arkcoll, D.B.; Some leguminous trees providing useful fruits in the North of Brazil, pp 235-239, (Refs. 13). This paper deals with Parkia platycephala, Pentaclethra macroloba, Swartzia sp., Cassia leiandra, Hymenaea courbaril, dipteryz odorata, Inga edulis, I. macrophylla, and I. cinnamonea. Baggio, A.J.; Possibilities of the use of Gliricidia sepium in agroforestry systems in Brazil, pp 241-243; (Refs. 15). Seiffert, N.F.; Biological nitrogen and protein production of Leucaena cultivars grown to supplement the nutrition of ruminants, pp 245-249, (Refs. 14). Leucaena leucocephala cv. Peru, L. campina grande (L. leucocephala), and L. cunningham (L. leucocephalae) were promising for use as browse by beef cattle in central Brazil.

  14. Water use, root activity and deep drainage within a perennial legume-grass pasture: A case study in southern inland Queensland, Australia

    Directory of Open Access Journals (Sweden)

    A. Nahuel A. Pachas

    2016-09-01

    Full Text Available Water use and depth of water extraction of leucaena (Leucaena leucocephala and Rhodes grass (Chloris gayana pasture, irrigated with desalinated coal seam water (a by-product of the coal seam gas industry, were monitored to provide background information on root activity, spatial and temporal water use and deep drainage over a 757-day period from August 2011 to August 2013. Methodology comprised measurement of soil water from surface to 4 m depth using 8 EnviroSCAN probes connected to dataloggers positioned within leucaena twin rows and within the Rhodes grass inter-row. Just over 581,000 individual moisture measurements were collated and are reported here. Water extraction (and by inference root activity of leucaena and Rhodes grass showed marked seasonal fluctuation with deepest and highest water extraction occurring during the first growing season; water extraction was greatly diminished during the following drier and cooler seasons due to the negative influences of lower soil moisture contents, lower temperatures and increased defoliation on pasture growth. The highest values of deep drainage below 4 m depth occurred when high rainfall events corresponded with high soil water storage in the entire profile (0–4 m depth. Given that water usage by both leucaena and Rhodes grass was greatest in the upper layers of soil (<1.5 m, future research should focus on how the level of competitive interaction might be managed by choice of row spacing and frequency of irrigation. Further studies are needed, including: (a physical sampling to determine the depth of active roots; (b how defoliation affects rooting behaviours and water use of leucaena; and (c modelling of the water and salt balances of leucaena and grass inter-row systems using data from this study, with various levels of irrigation, to investigate the risks of deep drainage over an extended climate sequence.Keywords: Active rooting depth, agroforestry, Chloris gayana, Leucaena leucocephala

  15. Effects of selected multipurpose, medicinal and aromatic plants on in ...

    African Journals Online (AJOL)

    The study was carried out to evaluate the effects of selected multipurpose, medicinal and aromatic plants on the in vitro methane production and microbial diversity. The plants include multi-purpose trees; Pterocarpus santallinoides, Leucaena leucocephala, Albizia lebbek, Albizia saman, Enterolobium cyclocarpum, ...

  16. GROWTH AND NODULATION OF LEUCAENA AND PROSOPIS SEEDLINGS IN SOIL PLUS TANNERY SLUDGE

    Directory of Open Access Journals (Sweden)

    Ademir Sérgio Ferreira de Araújo

    2006-01-01

    Full Text Available The objective of this paper was to evaluate the growth and nodulation of Leucaena and Prosopis seedlings in soil plus tannery sludge. The study was conducted in a greenhouse, using bags containing soil plus tannery sludge. Seedlings of Leucaena and Prosopis inoculated with Bradyrhizobium sp were used. Results were evaluated 90 days after plant emergency. The application of tannery sludge, in the rate of 11.250 kg per hectare significantly increased plant height, stem diameter, and above ground dry mass ofLeucaena. Regarding Prosopis, there were no significant increases in these variables with tannery sludge application, except for aerial dry mass. No significant differences were seen between the treatments with sludge and inoculated with Bradyrhizobium sp. as to nodule number and dry mass. Tannery sludge evaluated in this work did not affect nodulation, besides favoring Leucaena and Prosopis seedling growth.

  17. Role of bioinoculants and organic fertilizers in fodder production and quality of leguminous tree species.

    Science.gov (United States)

    Mishra, Seema; Sharma, Satyawati; Vasudevan, Padma

    2011-01-01

    The comparative effect of dual inoculation of native N fixer (Rhizobium) and AM fungi consortia with different organic fertilizers (vermicompost and farm yard manure) on fodder production and quality of two leguminous tree species (Leucaena leucocephala (Lam) de. Wit. and Sesbania sesban (L.) Merr.) in silvopastoral system and their impact on the fodder production of un-inoculated Panicum maximum Jacq. under cut and carry system. After three years of plantation maximum tree survival was in L. leucocephala in all the treatments in comparison to S. sesban while fodder production was more in S. sesban for initial two years and in third year it accelerated in L. leucocephala. Dual inoculation with vermicompost significantly improved fodder production, fodder quality and rhizosphere microflora in L. leucocephala but in S. sesban dual inoculation was at par with single inoculation of N fixer, AM fungi and control (without inoculation). The grass production was higher with L. leucocephala for two years while in third year it was more with S. sesban. The association of Rhizobium with AM fungi in L. leucocephala was better than in S. sesban.

  18. Evaluation of the Nutritional Potentials of Selected Multipurpose ...

    African Journals Online (AJOL)

    This experiment was conducted to evaluate the nutritional potentials of selected multipurpose fodder trees for use in livestock diets. Fresh leaves from five fodder tree species notably Gmelina arborea, Leucaena leucocephala, Tectona grandis, Persea americana and Dactyledila barteri obtained from the forestry unit of Imo ...

  19. Effect of mycorrhiza and pruning regimes on seasonality of ...

    African Journals Online (AJOL)

    Field experiments were carried out on an alley-cropping farm in Ajibode village, near Ibadan where cassava alley-cropped with three hedgerow trees (Leucaena leucocephala, Gliricidia sepium and Senna (Syn Cassia) siamea), and sole planted cassava (all in three replicates) were arranged with arbuscular mycorrhizal ...

  20. Salt tolerances of some mainland tree species select as through nursery screening.

    Science.gov (United States)

    Miah, Md Abdul Quddus

    2013-09-15

    A study of salt tolerance was carried out on germination, survival and height growth performance of important mesophytic species such as Acacia auriculiformis, Acacia hybrid, Artocarpus heterophyllus, Albizia procera, Albizia lebbeck, Acacia nilotica, Achras sapota, Casuarina equisetifolaia, Emblica officinalis, Leucaena leucocephala, Samania saman, Swetenia macrophylla, Terminalia arjuna, Tamarindus indica, Terminalia bellirica and Thespesia populnea in nursery stage using fresh water and salt (NaCl) solutions of 10, 15 and 20 ppm. Effect of salt on germination, survival performance and height growth performance were examined in this condition. Based on the observation, salt tolerance of these species has been determined Acacia auriculiformis, Acacia hybrid, Achras sapota, Casuarina equisetifolia, Leucaena leucocephala and Tamarindus indica has showed the best capacity to perform in different salinity conditions. Acacia nilotica, Emblica officinalis, Thespesia populnea has performed better. Albizia procera, Samania saman and Terminalia bellirica, germination and height performance showed good but when salinity increases survivability were decreases.

  1. 60 changes in soil properties under alley cropping system of three ...

    African Journals Online (AJOL)

    OLUWOLE AKINNAGBE

    2009-01-01

    Jan 1, 2009 ... A study to evaluate the changes in soil properties, under existing alley cropping system with three leguminous crops (Leucaena leucocephala ... of improved farming system is efficient recycling of organic materials. This exploits ... in form of violent shower of short duration. Rainfall is seasonal and defines ...

  2. Effect Of Feeding Hordeum jabatum Hay Supplemented With ...

    African Journals Online (AJOL)

    There were no differences (P>0.05) in the dry matter, organic matter, neutral detergent fibre, acid detergent fibre and hemicellulose intake among treatments. There were however, significant (P<0.05) differences in the digestibility of nutrients among treatments. It was concluded that dried leaves of Leucaena leucocephala ...

  3. Light fraction of soil organic matter under different management ...

    African Journals Online (AJOL)

    A study on light fraction organic matter was carried out on the soil from three different management systems namely; Gmelina arborea, Tectona grandis and Leucaena leucocephala plantations in the University of Agriculture, Abeokuta Nigeria. Soil samples were collected in each of the three management site at five auger ...

  4. EFFECT OF INVERSION ON TREATMENT OF FENCE SUBJECTED TO SAP DISPLACEMENT METHOD

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2014-03-01

    Full Text Available http://dx.doi.org/10.5902/1980509813338This work aimed to evaluate the effect of inversion of Prosopis juliflora and Leucaena leucocephala fenceposts, in distribution, penetration and retention of copper chrome borate (CCB solution applied by sapdisplacement method. The Prosopis juliflora was collected in Brazilian Agricultural Research Company(EMBRAPA and the Leucaena leucocephala at the Federal University of Campina Grande in Patos,Paraíba state, Brazil. Trees with DAP from 5.0 to 10.0 cm were employed. Disks of 2.0 cm of thicknesswere retired on the top and on the base of pieces. The external disks were then discarded and the internones were employed to determine the wood characteristics, being the round pieces with 2.0 m. A solutionof 2% of active ingredients of CCB was used to treated woods. A total of 10 pieces of each species weretreated, and five of them remained in the solution for 8 days and the five ones had their tops inverted afterthe sixth day of treatment. The pieces were seasoned; disks of 2.0 cm of thickness were taken in 5 positions along of pieces and the analyses for determination of copper and boron penetration took place. The valuesof wood characteristics indicated that the pieces were homogeneous. The absorption of the solution was of19.9 liters (Prosopis juliflora and of 17.0 liters (Leucaena leucocephala. The nominal retentions of CCBwere 7.72 and 5.34 kg active ingredients (a.i./m3, respectively. In general, the inversion of the pieces inthe preservative solution is recommended, by providing a better distribution, penetration and retention ofCCB on treated pieces.

  5. EFEITO DA INVERSÃO NO TRATAMENTO DE MOIRÕES SUBMETIDOS AO MÉTODO DE SUBSTITUIÇÃO DA SEIVA

    Directory of Open Access Journals (Sweden)

    Juarez Benigno Paes

    2014-01-01

    Full Text Available This work aimed to evaluate the effect of inversion of Prosopis juliflora and Leucaena leucocephala fence posts, in distribution, penetration and retention of copper chrome borate (CCB solution applied by sap displacement method. The Prosopis juliflora was collected in Brazilian Agricultural Research Company (EMBRAPA and the Leucaena leucocephala at the Federal University of Campina Grande in Patos, Paraíba state, Brazil. Trees with DAP from 5.0 to 10.0 cm were employed. Disks of 2.0 cm of thickness were retired on the top and on the base of pieces. The external disks were then discarded and the intern ones were employed to determine the wood characteristics, being the round pieces with 2.0 m. A solution of 2% of active ingredients of CCB was used to treated woods. A total of 10 pieces of each species were treated, and five of them remained in the solution for 8 days and the five ones had their tops inverted after the sixth day of treatment. The pieces were seasoned; disks of 2.0 cm of thickness were taken in 5 positions along of pieces and the analyses for determination of copper and boron penetration took place. The values of wood characteristics indicated that the pieces were homogeneous. The absorption of the solution was of 19.9 liters ( Prosopis juliflora and of 17.0 liters ( Leucaena leucocephala . The nominal retentions of CCB were 7.72 and 5.34 kg active ingredients (a.i./m 3 , respectively. In general, the inversion of the pieces in the preservative solution is recommended, by providing a better distribution, penetration and retention of CCB on treated pieces.

  6. Sheep response to sugar cane tops supplemented with varying ...

    African Journals Online (AJOL)

    Twenty WAD sheep averaging 10.14kg were randomly divided into four groups of 5 replicates, and each group was fed sugarcane tops (SCT) supplemented with varying levels (0%, 25%, 50 and 75%) of Leucaena leucocephala foliage (LLF) in a completely randomized design. Results showed that sugarcane tops (SCT) ...

  7. evaluating the performance of leucaena accessions for agroforestry

    African Journals Online (AJOL)

    Mgina

    The performance of Leucaena accessions on acid soils in eastern coast Tanzania for ... Plant tree parameters assessed were fodder yield and plant stem ... adapted and potential in improving soil fertility and are recommended for agroforestry.

  8. Biomass production on saline-alkaline soils

    Energy Technology Data Exchange (ETDEWEB)

    Chaturvedi, A.N.

    1985-01-01

    In a trial of twelve tree species (both nitrogen fixing and non-fixing) for fuel plantations on saline-alkaline soil derived from Gangetic alluvium silty clay, Leucaena leucocephala failed completely after showing rapid growth for six months. Results for other species at age two showed that Prosopis juliflora had the best productivity.

  9. Effect of coppicing height on the regeneration and productivity of certain firewood shrubs in alkaline soils of north Indian plains

    Energy Technology Data Exchange (ETDEWEB)

    Misra, P.N.; Tewari, S.K.; Singh, Dheer; Katiyar, R.S. [National Botanical Research Inst., Lucknow (India)

    1995-12-31

    Four shrubs, viz. Hibiscus tiliaceus, Leucaena leucocephala, Vitex negundo and Sesbania sesban, were evaluated for their performance as firewood crops in coppiced stands of varying cutting heights (15, 30 and 45 cm) in repeated annual harvests (4) on alkaline soils of the North Indian plains. The dry wood yield of Leucaena and Sesbania ranged between 22.9-42.6 and 9.9-18.0 tonnes ha{sup -1} year{sup -1}, respectively. Leucaena showed progressive increases in yield from coppiced stumps up to the 4th harvest while Sesbania showed a reduction after the third harvest mainly due to the high degeneration (60%) of coppiced stumps. Degeneration was low (< 10%) in Leucaena and Vitex. The coppicing heights generally did not show any significant effect on the growth and productivity. The number of coppice shoots per stump increased with stump height and production of coppice shoots was maximum in Vitex and minimum in Leucaena. The average diameter of coppice shoots tended to decrease with increasing coppicing height of the stumps. (author)

  10. Buffer nitrogen solubility, in vitro ruminal partitioning of nitrogen and in vitro ruminal biological activity of tannins in leaves of four fodder tree species.

    Science.gov (United States)

    Cudjoe, N; Mlambo, V

    2014-08-01

    This study explores the chemical composition, buffer N solubility, in vitro ruminal N degradability and in vitro ruminal biological activity of tannins in leaves from Gliricidia sepium, Leucaena leucocephala, Morus alba and Trichanthera gigantea trees. These tree leaves are a potential protein source for ruminants, but their site-influenced nutritive value is largely unknown. Leucaena leucocephala leaves had the highest N content (42.1 g/kg DM), while T. gigantea leaves had the least (26.1 g/kg DM). Leucaena leucocephala had the highest buffer solubility index (20%), while 10% of the total N in leaves of the other three species was soluble. The rapidly fermentable N fraction 'a' was highest in M. alba leaves (734.9 g/kg DM) and least in T. gigantea leaves (139.5 g/kg DM). The rate of fermentation (c) was highest for M. alba (7%/hours) leaves. No significant correlations were recorded between buffer solubility index of N and in vitro ruminal N degradability parameters: a, b, and c. The highest response to tannin inactivation using polyethylene glycol, in terms of percentage increase in 36-hours cumulative gas production, was recorded in M. alba (39%) and T. gigantea (38%) leaves. It was concluded that buffer solubility of N is not a good indicator of ruminal N degradation in the leaves of these tree species. Leaves of M. alba could be more valuable as a source of rapidly fermentable N when animals are offered low-protein, high-fibre diets compared with other tree species evaluated in the current study. However, when feeding M. alba leaves, the role of tannins must be considered because these secondary plant compounds showed significant in vitro ruminal biological activity. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

  11. 2075-IJBCS -Article-Maurice Ognalaga

    African Journals Online (AJOL)

    hp

    Leucaena leucocephalae et de C. odorata. Ils ont attribué cette réaction à la richesse chimique de ces deux engrais verts utilisés. De nombreux autres travaux comme ceux de. Choudhary et Suresh (2013) affirment que les amendements organiques libèrent lentement les nutriments dans le sol. En somme, il s'agirait d'une ...

  12. Comportamiento fenológico de 23 accesiones de Leucaena spp Phenological performance of 23 Leucaena spp. accessions

    Directory of Open Access Journals (Sweden)

    Hilda B Wencomo

    2010-12-01

    Full Text Available Se evaluaron 23 accesiones de Leucaena spp. de una colección de 180, con el objetivo de caracterizar el comportamiento de sus patrones fenológicos en la etapa de establecimiento; las plantas se sembraron a una distancia de 6 x 3 m entre surcos y entre plantas. Se contó el número de pinnas por hoja y de pínulas por pinna; además se midió la longitud y el ancho de las pínulas, la cantidad de legumbres por cabezuela, la longitud y el ancho de las legumbres. Se tuvo en cuenta la forma de las pinnas, el tipo y la posición de las glándulas y el color de las flores. La aparición de flores y frutos fue diferente entre las especies de este género, y se presentó sólo de forma anual en algunas de ellas. Las accesiones de cada especie tuvieron un comportamiento similar, tanto en lluvia como en seca, excepto L. diversifolia CIAT-17503, L. macrophylla CIAT-17233 y L. esculenta CIAT-17229 (las cuales se mantuvieron en fase vegetativa. Asimismo se pudo apreciar que las flores individuales de las especies y accesiones de Leucaena generalmente son pequeñas. Se concluye que existen diferencias entre las especies y accesiones evaluadas en esta fase; al igual que en el comportamiento de sus patrones de floración y fructificación.Twenty three Leucaena spp. accessions of a collection of 180 were evaluated, in order to characterize the performance of their phenological patterns in the establishment stage; the plants were sown at a distance of 6 x 3 m between rows and between plants. The number of pinnae per leaf and of pinnule per pinna was counted; in addition, the length and width of the pinnule were measured, and the quantity of legumes per capitulum, the length and width of the pods were determined. The form of the pinnae, the type and position of the glands and the color of he flowers were taken into consideration. The emergence of flowers and fruits was different among the species of this genus, and it occurred only annually in some of them. The

  13. Selection of species tolerant to the herbicide sulfentrazone with potential for phytoremediation of contaminated soilsSeleção de espécies tolerantes ao herbicida sulfentrazone com potencial para a fitorremediação de solos contaminados

    Directory of Open Access Journals (Sweden)

    João Carlos Madalão

    Full Text Available This paper aimed to select species with potential for phytoremediation of soils contaminated with the herbicide sulfentrazone. Eight species were evaluated: Arachis pintoi, Eleusine coracana, Crotalaria spectabilis, Crotalaria ochroleuca, Cajanus cajan, Leucaena leucocephala, Stizolobium cinereum, and Raphanus sativus. The experiment was set-up inside a greenhouse, using pots with a capacity of 6dm3 filled with soil samples collected at a depth of 0-20cm. The experimental design was arranged into randomised blocks in a factorial scheme (8 × 5 with four replications, which consisted of the combination between the species and five doses of sulfentrazone (0, 200, 400, 800, and 1,600g ha-1. The herbicide phytotoxicity, plant heights, and dry masses of shoots and roots were evaluated. The species Cajanus cajan and Leucaena leucocephala had a higher tolerance to sulfentrazone up to a dose of 400g ha-1, showing minor symptoms of phytotoxicity and smaller decreases in plant heights and in dry matter accumulation, both in the shoots and roots, when compared to the control treatment, indicating, thus, the potential to be used for further studies on phytoremediation of sulfentrazone in soil. Este trabalho teve como objetivo selecionar espécies com potencial para a fitorremediação de solos contaminados com o herbicida sulfentrazone. Foram avaliadas oito espécies: Arachis pintoi, Eleusine coracana, Crotalaria spectabilis, Crotalaria ochroleuca, Cajanus cajan, Leucaena leucocephala, Stizolobium cinereum e Raphanus sativus. O experimento foi instalado em casa de vegetação, com a utilização de vasos com capacidade para 6 dm3 preenchidos com porções de solo coletadas na profundidade de 0-20 cm. O delineamento experimental foi o de blocos casualizados em esquema fatorial 8 × 5, com quatro repetições, composto pela combinação entre as espécies e cinco doses do sulfentrazone (0, 200, 400, 800 e 1.600 g ha-1. Foram avaliadas a fitotoxicidade do

  14. Characterization of Leucaena (Leucaena leucephala) oil by direct analysis in real time (DART) ion source and gas chromatography

    International Nuclear Information System (INIS)

    Alam, M.; Alandis, N.M.; Sharmin, E.; Ahmad, N.; Alrayes, B.F.; Ali, D.

    2017-01-01

    For the first time, we report the characterization of triacylglycerols and fatty acids in Leucaena (Leucaena leucephala) oil [LUCO], an unexplored nontraditional non-medicinal plant belonging to the family Fabaceae. LUCO was converted to fatty acid methyl esters (FAMEs). We analyzed the triacylglycerols (TAGs) of pure LUCO and their FAMEs by time-of-flight mass spectrometry (TOF-MS) followed by multivariate analysis for discrimination among the FAMEs. Our investigations for the analysis of LUCO samples represent noble features of glycerides. A new type of ion source, coupled with high-resolution TOF-MS was applied for the comprehensive analysis of triacylglycerols. The composition of fatty acid based LUCO oil was studied using Gas Chromatography (GC-FID). The major fatty acid components of LUCO oil are linoleic acid (52.08%) oleic acid (21.26%), palmitic acid (7.91%) and stearic acid (6.01%). A metal analysis in LUCO was done by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The structural elucidation and thermal stability of LUCO were studied by FT-IR, 1H NMR, 13C NMR spectroscopic techniques and TGA-DSC, respectively. We also measured the cytotoxicity of LUCO [es

  15. Effects of varying dietary zinc levels on energy and nitrogen ...

    African Journals Online (AJOL)

    Parameters determined were dry matter intake (DMI), energy utilization and nitrogen utilization. The mean±SE of Panicum maximum, Andropogon gayanus, Pennisetum purpureum, Leucaena leucocephala and Gliricidia sepium, contained 31.2±5.0; 29.1± 3.0;34.6± 6.0; 45.0± 5.0 and 47.1± 4.0mg Zn/kg DM respectively.

  16. 2090 IJBCS -Article--Defang Henri Fualefac

    African Journals Online (AJOL)

    hp

    Leucaena. A la fin de l'essai, les animaux recevant 20% de L. leucocephala ont été les plus lourds (2237,50 g), suivis respectivement de ceux nourris avec 10 .... Concentrât minéraux azote et vitaminiques (10%). Tableau 2 : Coût de production d'un kilogramme de chaque ration et de production du kilogramme vif de lapin.

  17. Analysis of Leucaena mimosine, Acacia tannins and total phenols by near infrared reflectance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, M N.V. [Hyderabad Univ. (India). Dept. of Plant Sciences

    1995-11-01

    The mimosine contents of Leucaena foliage, Acacia tannins and total phenols from leaf, bark and pod were analyzed by a near infrared relectance spectrophotometer (Compscan 3000). A calibration equation (linear summation regression) was developed with near infrared spectral analysis software, using 30 spectra from old and young leaves of Leucaena and 23 spectra from different samples of Acacia. The near infrared analyzer calculated that the percentages of mimosine, total phenols and tannins are closely comparable to laboratory results. (author)

  18. Greening of wastelands. Proceedings of the national workshop on utilisation of wastelands for bio-energy

    Energy Technology Data Exchange (ETDEWEB)

    Hegde, N G; Abhiyankar, P D [eds.

    1986-01-01

    After eight introductory and concluding papers, there are 48 short papers by various authors on topics including legal and social aspects, the afforestation of saline and alkaline soils, tree species selection, subabul (Leucaena leucocephala) production and economics, biomass production for fuel, cultivation of fruit trees, use of fertilizers and irrigation, and projects in Madhya Pradesh, the Punjab, Uttar Pradesh, Tamil Nadu, Orissa, Karnataka and Maharashtra.

  19. Performance of rabbits fed Leucaena leucocephala and concentrate ...

    African Journals Online (AJOL)

    Four fryers which were fed the same % of concentrates and Aspilia africana served as the control. Growth rate decreased at the beginning of the study followed by satisfactory growth thereafter. The control animals had a higher growth rate compared to the other two groups (P< 0.05). Alopecia and decreased appetite were ...

  20. COMPONENTES NUTRICIONALES Y ANTIOXIDANTES DE DOS ESPECIES DE GUAJE (Leucaena spp.: UN RECURSO ANCESTRAL SUBUTILIZADO

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    Nallely Román-Cortés

    2014-01-01

    Full Text Available El guaje ( Leucaena spp. es una planta de vaina y semillas comestibles, un recurso ancestral subutilizado por los pueblos mesoamericanos. El valor nutricional y nutracéutico del guaje se desconoce pese a su consumo vigente en las poblaciones rurales. El objetivo de este trabajo fue evaluar el contenido de minerales, compo - nentes nutricionales y antioxidantes para contribuir a la revalorización alimentaria del guaje rojo ( L. esculenta Benth. y verde ( L. leucocephala Lam.. Los contenidos de antocianinas, flavonoides, fenoles totales, taninos y actividad antioxidante se cuantificaron, así como la composición proximal y mineral. Las semillas de guaje rojo superaron a las de guaje verde en los contenidos de N, Mg, Mn, P y Zn; en contraste, las semillas de guaje verde presentaron niveles mayores de Na y de Fe. El contenido de fibra cruda fue 10.55 y 10.07 % en guaje rojo y verde, respectivamente, mientras que el de proteína fue 33.12 % en guaje rojo y 31.7 % en el verde. El alto contenido de compuestos fenólicos fue mayor en las semillas frescas de guaje rojo (1,088.70 mg equivalentes de ácido gálico [EAG]·100 g -1 p. f. que en las verdes (969.09 mg EAG·100 g -1 p. f., pero las últimas presen - taron mayor cantidad de taninos. La elevada actividad secuestradora de radicales libres (97.22 a 98.11 % obtenida por el método ABTS ( á cido 2,2’-azino-bis(3-etilben-zotiazolin-6-sulfónico, puede estar asociada al contenido de compuestos fenólicos. En conclusión, las semillas de guaje podrían considerarse un alimento funcional, principalmente las de guaje rojo debido a su calidad nutricional y mayor actividad antioxidante.

  1. A comparative study on the effect of gamma-irradiation on growth and biomass yield in certain fuel-wood species

    International Nuclear Information System (INIS)

    Bandyopadhyay, B.; Nandy, A.K.; Mallick, R.; Chatterjee, A.

    1990-01-01

    A trial was conducted to study a comparative effect of gamma-radiation on the growth behaviour vis-a-vis biomass yield of Acacia nilotica Delite, Leucaena leucocephala (Lam) De Wit and Prosopis chilensis D.C (sub-family Mimosoidae). Dry seeds were exposed to 1, 2, 4, 8 and 16 KR doses of gammaradiation. Irradiat ed seeds were sown in the field along with the control. In case of L. leucocephala the growth of the plants as well as total biomass production increased steadily with increasing doses of irradiation upto 8 KR. In A. nilotica the response was similar to that of L leucocephala, but in this case maximum growth and biomass yield was obtained after 4 KR. On the other hand, P. chilensis did not exhibit a positive response to gammaradiation. Karyotype of the three species was also done. All these observations indicate the greater possibility of the utilization of gammaradiation in increasing biomass production. (author). 12 refs., 2 tabs., 7 figs

  2. Efecto de la suplementación con concentrado en la fermentación in vitro de dietas para vacas lecheras en silvopastoreo

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    O López

    Full Text Available Se evaluó el efecto de la suplementación con concentrado (C0: control; C5: 5 % de los requerimientos de EM; C10: 10 % de los requerimientos de EM en la degradabilidad ruminal de dietas para vacas lecheras basadas en Panicum maximum y Leucaena leucocephala, mediante la técnica de producción de gas (PG in vitro. Para formular las dietas se asumió que los animales pesaban 480 kg, que estaban en su tercera lactancia y producían 10 kg de leche diarios, lo cual es representativo de la vaquería donde se tomaron las muestras de alimento. Se estimó la PG in vitro, los parámetros de la producción de gas (b, c, L, la digestibilidad in vitro de la materia seca (DIVMS, la energía metabolizable (EM y los ácidos grasos de cadena corta (AGCC, los cuales se compararon mediante un análisis de varianza, en un diseño completamente aleatorizado con tres tratamientos y tres repeticiones. Las dietas se incubaron in vitro, y para ello se utilizó inóculo ruminal de vacas Limousine, clínicamente sanas. La suplementación con concentrado incrementó linealmente (p < 0,01 la producción de gas a las 24 h y a las 48 h; mientras que a las 96 h el efecto fue cuadrático (p < 0,05, con el menor valor para C5. La DIVMS y la EM (p < 0,001, así como los AGCC (p < 0,05, se incrementaron linealmente con el aumento del concentrado, aunque en C10 la DIVMS fue menor; sin embargo, se incrementó la EM y los AGCC. Se concluye que en dietas basadas en P. maximum y L. leucocephala la adición de concentrado en un 5 % no tuvo efecto en la EM ni en la producción de AGCC, por lo que es necesario adicionar al menos un 10 % de este suplemento a la dieta, con base en los requerimientos de EM de los animales.

  3. Proximate chemical composition of giant ipil-ipil wood from different sources

    Energy Technology Data Exchange (ETDEWEB)

    Escolano, E U; Gonzales, E V; Semana, J A

    1978-01-01

    Studies of the chemical composition of seven samples of giant ipil-ipil (Leucaena leucocephala) yielded holocellulose, 69.8 to 73.9%; pentosans, 8.9 to 20.1%; lignin, 21.8 to 26%; alcohol-benzene solubles, 1.4 to 3.0%; caustic soda solubles, 13.0 to 16.4%; and ash, 0.7 to 0.9%. Based on chemical composition, this should be a suitable species for pulp and paper. (Refs. 11).

  4. NATURAL RESISTANCE OF SEVEN WOODS TO XYLOPHOGOUS FUNGI AND TERMITES UNDER LABORATORY CONDITION

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    Juarez Benigno Paes

    2007-06-01

    Full Text Available This research aimed at evaluating the natural resistance of seven woods to xylophogous fungi and subterranean termites under laboratory assay. The studied woods were Leucaena leucocephala, Cordia trichotoma, Mimosa tenuiflora, Croton sonderianus, Mimosa caesalpiniifolia, Azadirachta indica and Tectona grandis. Test samples measuring 2.54 x 2.00 x 1.00 cm (fungi and 2.54 x 2.00 x 0.64 cm (termites, with larger dimensions in fiber direction were obtained in four positions in pith-to-bark direction. The samples were submitted by 98 days to action of Postia placenta and Polyporus fumosus fungi or 28 days to the termite Nasutitermes corniger action. To fungi, the Mimosa tenuiflora and Mimosa caesalpiniifolia woods were the more resistant and those of Azadirachta indica and Croton sonderianus the less resistant. The fungus Postia placenta attacked more severely the tested woods. To termites, the Mimosa tenuiflora, Cordia trichotoma, and Mimosa caesalpiniifolia were the most resistant and the Leucaena leucocephala the less resistant. The coming wood of external section of log were the more attacked. To fungi, there was an inverse relationship between the density and the loss of mass. Already for the termites, there was not relationship between the resistance and the density of the wood.

  5. Tombamento de mudas de espécies florestais causado por Sclerotium rolfsii Sacc Damping-off of forest species caused by Sclerotium rolfsii Sacc

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    Reginaldo Gonçalves Mafia

    2007-08-01

    Full Text Available O estudo objetivou avaliar a gama de hospedeiros de Sclerotium rolfsii por inoculação controlada das seguintes espécies florestais nativas e exóticas: Anadenanthera peregrina (angico-vermelho, Chorisia speciosa (paineira-rosa, Clitoria fairchildiana (sombreiro, Copaifera langsdorffii (copaíba, Delonix regia (flamboyant-vermelho, Enterolobium contortisiliquum (orelha-de-negro, Leucaena leucocephala (leucena, Mabea fistulifera (canudo-de-pito, Platymiscium pubescens (tamboril-da-mata, Senna macranthera (fedegoso, Spathodea campanulata (espatódea e Tabebuia avellanedae (ipê-roxo, bem como comprovar o tombamento de mudas em pré e pós-emergência. Todas as espécies foram suscetíveis ao tombamento de mudas causado por S. rolfsii, em pré e em pós-emergência.The host range of Sclerotium rolfsii was evaluated by controlled inoculation of the following native and exotic forest species: Anadenanthera peregrina (angico vermelho, Chorisia speciosa (paineira rosa, Clitoria fairchildiana (sombreiro, Copaifera langsdorffii (copaíba, Delonix regia (flamboyant vermelho, Enterolobium contortisiliquum (orelha de negro, Leucaena leucocephala (leucena, Mabea fistulifera (canudo-de-pito, Platymiscium pubescens (tamboril da mata, Senna macranthera (fedegoso, Spathodea campanulata (espatódea e Tabebuia avellanedae (ipê roxo. The fungus caused damping-off in pre and post emergence in all tested species.

  6. Effect of six tropical tanniferous plant extracts on larval exsheathment of Haemonchus contortus Efeito de seis extratos de plantas taniníferas tropicais sobre o desembainhamento larvar de Haemochus contortus

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    Lorena Mayana Beserra de Oliveira

    2011-06-01

    Full Text Available Tanniferous plants represent a promising alternative for controlling gastrointestinal nematodes of small ruminants. This experiment evaluated the effects of extracts from the leaf and stem of Anadenanthera colubrina, Leucaena leucocephala and Mimosa tenuiflora on larval exsheathment of Haemonchus contortus in vitro and verified the role of tannins in this process. Third-stage larvae of H. contortus were incubated with extracts for 3 hours and were exposed to sodium hypochlorite solution. The extracts were tested at 300 µg.mL-1 and accompanied by controls: phosphate buffer solution (PBS and polyvinyl polypyrrolidone (PVPP. The larval exsheathment was evaluated for 60 minutes, and the results were subjected to the Kruskal-Wallis test (p 0.05, except for L. leucocephala and M. tenuiflora leaf extracts. However, pre-incubation with PVPP of these two extracts significantly changed larval exsheathment when compared to the non-treated extracts (p Plantas taniníferas representam uma promissora alternativa de controle dos nematóides gastrintestinais de pequenos ruminantes. Esse experimento avaliou in vitro os efeitos dos extratos das folhas e caules de Anadenanthera colubrina, Leucaena leucocephala e Mimosa tenuiflora sobre o desembainhamento larvar de Haemonchus contortus e verificou o papel dos taninos nesse processo. Larvas de terceiro estádio de H. contortus foram incubadas com 300 µg.mL-1 de extrato por 3 horas e expostas a uma solução de hipoclorito de sódio. O ensaio foi acompanhado por controles: solução salina tamponada com fosfato (PBS e polivinilpolipirrolidona (PVPP. O desembainhamento larvar foi avaliado durante 60 minutos e os resultados submetidos ao teste Kruskal-Wallis (p 0,05, exceto nos extratos das folhas de L. leucocephala e M. tenuiflora. Entretanto, a pré-incubação desses dois extratos com PVPP alterou significativamente o desembainhamento quando comparado com extratos não-tratados (p < 0,05. Esses resultados sugerem

  7. Effect of local tree seeds in the control of root knot nematode Meloidogyne javanica (Treub chitwood and growth promotion of chickpea (Cicer arietinum L. and mung bean (Vigna radiata L.

    Directory of Open Access Journals (Sweden)

    Zainab M. Ahmed

    2012-12-01

    Full Text Available Seeds of local trees, such Azadirachta indica A. Juss, Adenanthera pavonina L., Leucaena leucocephala (Lam. de Wit and Eucalyptus spp., were used as aqueous extract at 25, 50 and 100 % concentration to control the activity of Meloidogyne javanica (Treub Citwood. All seed extracts showed lethal effect on M. javanica eggs, and a gradual decrease in egg hatching and an increase in mortality of second-stage juveniles were observed with the increase in extract concentration. L. leucocephala was found to be most effective in reducing egg hatching, whereas 100 % mortality of juveniles was observed in the case of A. indica seed extract. Number of knots was significantly reduced at 100 % concentration when seeds of chick pea and mung bean were treated and soil was drenched with A. pavonina and Eucalyptus spp. seed extract.

  8. Animals and trees: food for thought

    Energy Technology Data Exchange (ETDEWEB)

    Openshaw, K.

    1979-01-01

    In many areas of Africa, combining tree-growing with animal rearing is advantageous, as the trees provide shade, animal fodder and timber for fuel and building, while grazing animals reduce the fire hazard from ground vegetation and improve soil fertility through droppings. Acacia albida, Prosopis cineraria, P. chilensis, leucaena leucocephala and Ailanthus excelsa are discussed as promising fodder trees, and an appendix is included with notes on 21 other trees for fodder or the production of medicines.

  9. Albizia lebbeck, Leucaena leucocephala, Morinda lucida and Senna si

    African Journals Online (AJOL)

    SARAH

    2017-09-30

    Sep 30, 2017 ... Université des Sciences et Techniques de Masuku .... corresponded to the beginning of the dry season, while ... Statistical analysis: For each foliage data of nutrient .... Arbouche Y, Arbouche HS, Arbouche F, Arbouche R,.

  10. Proporsi penggunaan berbagai jenis daun tanaman untuk pakan ternak kambing pada lokasi dan ketinggian berbeda di wilayah Malang Raya

    Directory of Open Access Journals (Sweden)

    Sri Susanti

    2016-12-01

    Full Text Available This research aims at investigating the proportion of several types of tree foliages leaves as animal feed in different locations and altitudes in Malang Raya. The case study was conducted in five districts of Malang Raya where were assumed as the centre of goat farms. The results showed that there were 30 types of forage used as goat feeds, both leaves of tree foliages and shrubs, or grasses, crop residues and others. Most forages (73% were leaves of tree foliages and shrubs, both legumes, and non-legumes. Tree foliage leaves were more used as goat feeds in the study area with higher altitude, whereas in the area with lower altitude, farmers also utilized grasses and crop residues. The leaves of tree foliages were Paraserianthes falcataria, Gliricidia sepium, Artocarpus heterophyllus, Leucaena leucocephala and Calliandra calothyrsus. Paraserianthes falcataria was most widely used in Klampok-Singosari (88.3%. The proportion of Calliandra calothyrsus ranged from 32 to 98%, while Gliricidia sepium was 58-98%, both were most widely used in Argoyuwono-Ampelgading. Artocarpus heterophyllus was most widely used in Wajak (90.3%, whereas Leucaena leucocephala leaf was used by all respondents (100% in Sumberdem-Wonosari. It is necessary to evaluate the quality of these tree foliage leaves to provide a better animal feed through supplementation technology. Keyword: altitudes, foliages, leave, location

  11. Comparación de tres leguminosas arbóreas sembradas en un sustrato alcalino durante el período de aviveramiento. I. Variables morfoestructurales Comparison of three tree legumes planted on an alkaline substratum during the nursery stage. I. Morphostructural variables

    Directory of Open Access Journals (Sweden)

    María G Medina

    2011-03-01

    Full Text Available Se llevó a cabo un ensayo en el estado Trujillo, Venezuela, con el objetivo de evaluar el comportamiento morfoestructural de Albizia lebbeck, Leucaena leucocephala (ecotipo Trujillo y Erythrina fusca en condiciones de vivero. Se utilizó un diseño completamente aleatorizado para mediciones repetidas en el tiempo y diez réplicas por especie. Las variables estudiadas fueron: altura de la planta; diámetro del tallo y de las ramas; número de hojas, ramas, raíces y nódulos totales; y longitud de la rama y de la raíz. Al final de la evaluación (18 semanas no se observaron diferencias significativas entre L. leucocephala y E. fusca en la altura de la planta (45,2 y 51,0 cm, el diámetro del tallo (0,65 y 0,78 cm, el número de hojas (43 y 45 y de ramas (17 y 18 y la longitud de la raíz (32,1 y 36,5 cm. A. lebbeck sólo se destacó en el número de raíces (61 y de nódulos totales promedio (6. Los resultados permiten concluir que con la utilización de un sustrato alcalino en vivero, L. leucocephala y E. fusca exhibieron un comportamiento morfoestructural aéreo similar y superior que el de A. lebbeck; mientras que la albizia mostró mejores resultados en la morfoestructura radical.A trial was conducted in the Trujillo state, Venezuela, in order to evaluate the morphostructural performance of Albizia lebbeck, Leucaena leucocephala (Trujillo ecotype and Erythrina fusca under nursery conditions. A completely randomized design was used for repeated measurements in time and ten replications per species. The studied variables were: plant height; stem and branch diameter; number of leaves, branches, roots and total nodules; and branch and root length. At the end of the evaluation (18 weeks no significant differences were observed between L. leucocephala and E. fusca in plant height (45,2 and 51,0 cm, stem diameter (0,65 and 0,78 cm, number of leaves (43 and 45 and branches (17 and 18 and root length (32,1 and 36,5 cm. A. lebbeck only stood out for

  12. Preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, formicidae a diferentes espécies florestais, em condições de laboratório.

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    Otávio Peres Filho

    2010-08-01

    Full Text Available Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea, leucena (Leucaena leucocephala, pau-ferro (Caesalpinia ferrea, albizia (Albizia lebbeck e orelha-de-negro (Enterolobium contortisiliquum e as menos transportadas foram eucalipto (Eucalyptus grandis, jequitibá (Cariniana strellensis e mutamba (Guazuma tomentosa.

  13. PREFERÊNCIA DE SAÚVA LIMÃO, Atta sexdens rubropilosa Forel, 1908 (HYMENOPTERA, FORMICIDAE A DIFERENTES ESPÉCIES FLORESTAIS, EM CONDIÇÕES DE LABORATÓRIO

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    Otávio Peres Filho

    2002-08-01

    Full Text Available Avaliou-se a preferência de saúva limão, Atta sexdens rubropilosa Forel, 1908, para 41 espécies florestais nativas e exóticas, em condições de laboratório. As espécies mais transportadas foram gmelina (Gmelina arborea, leucena (Leucaena leucocephala, pau-ferro (Caesalpinia ferrea, albizia (Albizia lebbeck e orelha-de-negro (Enterolobium contortisiliquum e as menos transportadas foram eucalipto (Eucalyptus grandis, jequitibá (Cariniana strellensis e mutamba (Guazuma tomentosa .

  14. Avaliação de genótipos de Leucaena spp. nas condições edafoclimáticas de São Carlos,SP: II. determinações bromatológicas no período de estabelecimento Evaluation of Leucaena spp. genotypes in the edaphic and climatic conditions of São Carlos, SP: II. bromatological determinations at the establishment period

    Directory of Open Access Journals (Sweden)

    A.C.P. de A. Primavesi

    1994-04-01

    Full Text Available Em experimento conduzido em Latossolo Vermelho-Amarelo distrófico, em área da EMBRAPA - CPPSE em São Carlos, situada a 22°01'S e 47°53'W, com altitude de 856 m e média de precipitação anual de 1502 mm, procedeu-se a determinação da composição bromatológicade folhas, hastes com diâmetro menor que 6 mm e vagens, de genótipos de leucena. Os genótipos avaliados, foram: L.leucocephala cv. Texas 1074 (TI, L.leucocephala 29 A9 (T2, L.leucocephala 11 x L.dlversifolia 25 (T3, L.leucocephala 11 x L.diversifolia 26 (T4, L.leucocephala 24-19/2-39 x L.diverstfolia 26 (T5 e L.leucocephala c v. Cunningham (testemunha. Verificou-se que: os genótipos avahados não apresentaram diferenças nas determinações bromatológicas, realizadas nas folhas e talos finos; o genótipo T3 registrou o maior teor de proteína bruta (28,06%, de fósforo (0,29% e a maior relação PB/FDN e o menor teor de FDN para vagens; os genótipos apresentaram os seguintes teores médios, em porcentagem, para a composição bromatológicadas folhas, vagens e talos finos, respectivamente: Proteína bruta (18,57; 21,68; 6,41; Fibra detergente neutro (29,09; 41,58; 71,01; Fósforo (0,12; 0,22; 0,06; Cálcio (1,39; 0,36; 0,49; Magnesio (0,51; 0,28; 0,24; Tanino (1,32; 1,15; 0,28 e Digestibilidade "in vitro" (58,39; 61,22; 33,61; os teores de proteína e fósforo apresentaram a seguinte ordem decrescente nas partes das plantas: vagens > folhas > talos finos; os teores de cálcio: folhas > talos finos > vagens e de magnésio: folhas > vagens > talos finos.In a trial conducted on a distrofic Red-Yellow Latossol, at EMBRAPA-CPPSE, São Carlos, located at 22°01'S and 47'53'W, altitude of 856 m and with a mean annual rainfall of 1502 mm, the bromatological composition of leaves, stems smaller than 6 mm diameter and pods of leucena genotypes was determined. The genotypes evaluated were: L.leucocephala cv. Texas 1074 (T1, L.leucocephala 29 A9 (T2, L.leucocephala 11 x L.dlversifolia 25

  15. Evaluation of the comparative growth and reproductive performance of West African dwarf goats in the western highlands of Cameroon[(AFRA - African Regional Co-operative Agreement for Research, Development and Training related to Nuclear Science and Technology)

    Energy Technology Data Exchange (ETDEWEB)

    Tedonkeng Pamo, E; Tendonkeng, F; Kadjio, J T.T.; Kwami, H N; Taboum, R K; Kana, J R; Tegodjeu, A [University of Dschang, FASA, Department of Animal Sciences, Dschang (Cameroon)

    2002-06-01

    On-farm and on-station evaluations of the comparative growth performance of West African Dwarf Goats supplemented at an iso-nitrogenous level (6 g/animal/day) with leguminous browse Calliandra calothyrsus, Leucaena leucocephala, or Gliricidia sepium, or with cotton seed cake, were conducted around Dschang in the Western Highlands of Cameroon and at the University Experimental Farm. The animals were weighed every 21 days during the rainy season and every 14 days during the dry season for three months to evaluate their response to supplementation. Cotton seed cake, L. leucocephala, C. calothyrsus were the most accepted supplements. The weight gain of the animals fed with these supplements was significantly higher compared to that of the control animals. Mean weight of animals supplemented with G. sepium was not significantly different (P>0.05) from that of the control group during the rainy season. The average daily weight gains during the rainy period were 20.6, 19.1, 13.8, 4.5, and 3.1 g for L. leucocephala, cotton seed cake, C. calothyrsus, G. sepium and the control animals respectively, during the rainy season and 19.9, 16.1 and 1.7 g for cotton seed cake, L. leucocephala and the control animal respectively, during the dry season. Progesterone profiles were low and were unaffected by supplementation during the dry season. (author)

  16. Evaluation of the comparative growth and reproductive performance of West African dwarf goats in the western highlands of Cameroon

    International Nuclear Information System (INIS)

    Tedonkeng Pamo, E.; Tendonkeng, F.; Kadjio, J.T.T.; Kwami, H.N.; Taboum, R.K.; Kana, J.R.; Tegodjeu, A.

    2002-01-01

    On-farm and on-station evaluations of the comparative growth performance of West African Dwarf Goats supplemented at an iso-nitrogenous level (6 g/animal/day) with leguminous browse Calliandra calothyrsus, Leucaena leucocephala, or Gliricidia sepium, or with cotton seed cake, were conducted around Dschang in the Western Highlands of Cameroon and at the University Experimental Farm. The animals were weighed every 21 days during the rainy season and every 14 days during the dry season for three months to evaluate their response to supplementation. Cotton seed cake, L. leucocephala, C. calothyrsus were the most accepted supplements. The weight gain of the animals fed with these supplements was significantly higher compared to that of the control animals. Mean weight of animals supplemented with G. sepium was not significantly different (P>0.05) from that of the control group during the rainy season. The average daily weight gains during the rainy period were 20.6, 19.1, 13.8, 4.5, and 3.1 g for L. leucocephala, cotton seed cake, C. calothyrsus, G. sepium and the control animals respectively, during the rainy season and 19.9, 16.1 and 1.7 g for cotton seed cake, L. leucocephala and the control animal respectively, during the dry season. Progesterone profiles were low and were unaffected by supplementation during the dry season. (author)

  17. Nutritional quality and fractionation of carbohydrates and protein in the forage components of an intensive silvopastoral system

    International Nuclear Information System (INIS)

    Gaviria, Xiomara; Rivera, J.E.; Barahona, R.

    2015-01-01

    The objective of this study was to evaluate the nutritional quality of the forage components of a SPSi based on Leucaena leucocephala associated to improved pastures, as well as its biomass production. The forage production was determined at several moments of the year and the nutritional quality was evaluated through the Cornell model. The soluble protein proportion (fraction A) was similar between the grasses and L. leucocephala, and represented as minimum 34 % of the total protein. The proportion of protein B2 (intermediate degradation) of the legume was higher than that of the grasses (53,7 vs. 30,2 %, respectively). Protein B3 of the diet (slow degradation) was around 22 % of the total protein, and more than 71 % of it can be considered degradable in rumen. L. leucocephala showed a higher concentration of soluble carbohydrates (16,7 %) and lower quantity of fraction B2 (14,94 %) than the grasses. Concerning the biomass availability, a production of 19,26 t DM/ha year-1 was reached. It is concluded that in SPSis a high quantity of quality forage is produced throughout the year, and that this offer is sufficient to cover the requirements of ruminants. (author)

  18. Effects of tropical high tannin non legume and low tannin legume browse mixtures on fermentation parameters and methanogenesis using gas production technique.

    Science.gov (United States)

    Seresinhe, T; Madushika, S A C; Seresinhe, Y; Lal, P K; Orskov, E R

    2012-10-01

    In vitro experiments were conducted to evaluate the suitability of several mixtures of high tanniniferous non legumes with low tanniniferous legumes on in vitro gas production (IVGP), dry matter degradation, Ammonia-N, methane production and microbial population. Eight treatments were examined in a randomized complete block design using four non-legumes and two legumes (Carallia integerrima×Leucaena leucocephala (LL) (Trt 1), C. integerrima×Gliricidia sepium (GS) (Trt 2), Aporosa lindeliyana×LL (Trt 3), A. lindeliyana×GS (Trt 4), Ceiba perntandra×LL (Trt 5), C. perntandra×GS (Trt 6), Artocarpus heterophyllus×LL (Trt 7), A. heterophyllus×GS (Trt 8). The condensed tannin (CT) content of non legumes ranged from 6.2% (Carallia integerrima) to 4.9% (Ceiba perntandra) while the CT of legumes were 1.58% (Leucaena leucocephala) and 0.78% (Gliricidia sepium). Forage mixtures contained more than 14% of crude protein (CP) while the CT content ranged from 2.8% to 4.0% respectively. Differences (pheterophyllus×L. leucocephala (Trt 7) and A. heterophyllus×G. sepium (Trt 8). Highest (p>0.05) NH3-N (ml/200 mg DM) production was observed with the A. heterophyllus×G. sepium (Trt 8) mixture which may be attributed with it's highest CP content. The correlation between IVGP and CT was 0.675 while IVGP and CP was 0.610. In vitro dry matter degradation (IVDMD) was highest in Trt 8 as well. Methane production ranged from 2.57 to 4.79 (ml/200 mg DM) to be synonimous with IVGP. A higher bacteria population (pArtocarpus heterophyllus+G. sepium (Trt 8) and the same trend was observed with the protozoa population as well. The results show that supplementing high tannin non leguminous forages by incremental substitution of legume forage increased gas production parameters, NH3-N, IVDMD and microbial population in the fermentation liquid. Methane production was not significantly affected by the presence of CT or different levels of CP in forage mixtures. Among non legumes, Ceiba

  19. Diversidad zoológica asociada a un silvopastoreo leucaena-guinea con diferentes edades de establecimiento Zoological diversity associated to a silvopastural system leucaena-guinea grass with different establishment times

    Directory of Open Access Journals (Sweden)

    Jatnel Alonso Lazo

    2007-12-01

    Full Text Available El objetivo de este trabajo fue evaluar la diversidad zoológica asociada a un silvopastoreo con leucaena-guinea, por medio de la caracterización de la composición y estructura de las aves, insectos y la macrofauna del suelo, en cuatro edades de establecimiento (3, 4, 5 y 6 años de explotación. Con las especies registradas en cada uno de estos grupos zoológicos, se calcularon los índices ecológicos: número de individuos, riqueza, diversidad y abundancia de especies, en diferentes edades del sistema. En todos los grupos, se apreció el aumento significativo en la riqueza de especies y en el índice de diversidad biológica de Shannon, en la medida que se desarrolló el sistema. Se observó incremento en la abundancia de insectos biorreguladores y, en relación con las aves, el horario de muestreo no mostró interacción con los distintos años de siembra. La macrofauna se incrementó, observándose dominancia de anélidos al 6º y 7º año de explotación, caracterizado por Polyferetrina elongata y Oligochaeta elegans. El desarrollo del silvopastoreo leucaena-guinea logra sistemas productivos pecuarios que aumentan la producción de biomasa y de otros componentes biológicos y contribuir para crear un sistema sostenible y compatible con el ambiente.The aim of this work was to evaluate the associated zoological diversity of a silvopastural system leucaena-guinea grass, by characterizing the composition and structures of the birds, insects and the macrofauna of the soil, in four establishment times of the silvopastural systems (3, 4, 5 and 6 years of exploitation. For the species recorded in each zoological group, the following ecological indices were determined: number of individuals, richness, diversity and abundance of species, in each establishment times of the system. A significant increase, in all the zoological groups, was observed for the richness of species and for the index of biological diversity of Shannon, as the system

  20. Degradabilidade ruminal da matéria seca, da fração fibrosa e da proteína bruta de forrageiras Forages dry matter, fibrous fraction and crude protein ruminal degradability

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    Aureliano José Vieira Pires

    2006-04-01

    Full Text Available O objetivo deste trabalho foi avaliar a degradabilidade ruminal da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta da alfafa (Medicago sativa, aveia-preta (Avena strigosa, leucena (Leucaena leucocephala e guandu (Cajanus cajan. Amostras de 3 g das forragens foram incubadas no rúmen de três novilhos por períodos de 0, 6, 12, 24, 36, 48 e 72 horas. As degradabilidades efetivas da matéria seca da alfafa e da aveia, para a taxa de passagem de 5% por hora, foram elevadas (acima de 60%. A leucena e o guandu apresentaram valores inferiores, 50,9 e 56,0%, respectivamente. A partir de 24 horas de incubação, a aveia se destacou com maior desaparecimento da fibra em detergente neutro e da fibra em detergente ácido, e ainda apresentou as mais elevadas taxas de degradação efetiva destas frações. A aveia foi a forragem que apresentou maior degradabilidade da matéria seca, da fibra em detergente neutro, da fibra em detergente ácido e da proteína bruta no rúmen. O guandu, entretanto, foi a forragem com as piores taxas de degradação.The objective of this work was to evaluate ruminal degradability of dry matter, neutral detergent fiber, acid detergent fiber and crude protein of alfalfa (Medicago sativa, black oat (Avena strigosa, leucaena (Leucaena leucocephala and pigeon pea (Cajanus cajan. Samples of 3 g of forages were incubated in the rumen of three steers for 0, 6, 12, 24, 36, 48 and 72 hours periods. The dry matter effective degradabilities of alfalfa and oat, for a passage rate of 5%/hour, were high (over 60%. However, leucaena and pigeon pea showed lower values, 50.9 and 56.0%, respectively. From 24-hour incubation period on, the oat presented the highest neutral detergent fiber and acid detergent fiber disappearance and showed the greatest effective degradation rates of these fractions. The oat was the forage with the highest dry matter, neutral detergent fiber, acid detergent fiber and

  1. KEANEKARAGAMAN VEGETASI DAN PROFIL HABITAT DI TAMAN KEHATI UNIVERSITAS NEGERI SEMARANG

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    Bambang Priyono

    2014-02-01

    Full Text Available Taman Kehati Unnes merupakan salah satu kawasan yang dirancang sebagai kawasan konservasi tanaman lokal Jawa Tengah.Penelitian tahun sebelumnya telah dilakukan analisis keanekaragaman jenis fauna di Taman Kehati Unnes. Penelitian sebelumnya (2013 menunjukan di Taman Kehati Unnes tercatat sebanyak 24 jenisburung, 63 jenis kupu-kupu, dan 26 jenis herpetofauna (amfibi dan reptil berhasil diidentifikasi. Keanekaragaman fauna juga ditentukan oleh kondisi habitatnya, oleh karena itu tujuan penelitian ini adalah melakukan analisis profil habitat. Pengambilan data vegetasi dilakukan menggunakan metode garis berpetak berukuran 20 x 20 m untuk tingkat pohon, 10 x 10 m untuk tingkat tiang, 5 x 5 m untuk pancang, 2 x 2 untuk semai, dan 1 x 1 untuk. Profil vegetasi dibuat dari struktur vertikal penutupan tajukdengan membuat petak ukuran pemanfaatan 40 x20 m. Pengukuran dilakukan terhadap kedudukan vegetasi, penutupan tajuk, arah tajuk, tinggi tajuk, tinggi bekas cabang vegetasi, dan diameter batang. Hasil penelitian dari 52 petak sampel vegetasi di Taman Kehati Unnes menunjukkan sebanyak 32 jenis tumbuhan herba atau perdu, 13 jenis Pancang, 12 jenis tiang dan 7 jenis pohon dapat diidentifikasi. Jenis rumput yang paling mendominasi adalah Imperata cylindrica (Alang-alang dengan nilai INP 37.85 tanaman tersebut adalah jenis gulma yang biasa terdapat ditempat terbuka dan terganggu.Jenis tanaman yang paling mendominasi dari kelas pohon, pancangdan tiang adalahLeucaena leucocephala(Mlandingan. Hasil analisis menunjukan Taman Kehati Unnes memiliki tumbuhan yang sangat seragam, hal ini dapat dilihat dari dominasi Mlandingan (Leucaena leucocephala.

  2. KEANEKARAGAMAN VEGETASI DAN PROFIL HABITAT DI TAMAN KEHATI UNIVERSITAS NEGERI SEMARANG

    Directory of Open Access Journals (Sweden)

    Bambang P

    2015-02-01

    Full Text Available Taman Kehati Unnes merupakan salah satu kawasan yang dirancang sebagai kawasan konservasi tanaman lokal Jawa Tengah.Penelitian tahun sebelumnya telah dilakukan analisis keanekaragaman jenis fauna di Taman Kehati Unnes. Penelitian sebelumnya (2013 menunjukan di Taman Kehati Unnes tercatat sebanyak 24 jenisburung, 63 jenis kupu-kupu, dan 26 jenis herpetofauna (amfibi dan reptil berhasil diidentifikasi. Keanekaragaman fauna juga ditentukan oleh kondisi habitatnya, oleh karena itu tujuan penelitian ini adalah melakukan analisis profil habitat. Pengambilan data vegetasi dilakukan menggunakan metode garis berpetak berukuran 20 x 20 m untuk tingkat pohon, 10 x 10 m untuk tingkat tiang, 5 x 5 m untuk pancang, 2 x 2 untuk semai, dan 1 x 1 untuk.Profil vegetasi dibuat dari struktur vertikal penutupan tajukdengan membuat petak ukuran pemanfaatan 40 x 20 m. Pengukuran dilakukan terhadap kedudukan vegetasi, penutupan tajuk, arah tajuk, tinggi tajuk, tinggi bekas cabang vegetasi, dan diameter batang. Hasil penelitian dari 52 petak sampel vegetasi di Taman Kehati Unnes menunjukkan sebanyak 32 jenis tumbuhan herba atau perdu, 13 jenis Pancang, 12 jenis tiang dan 7 jenis pohon dapat diidentifikasi. Jenis rumput yang paling mendominasi adalah Imperata cylindrica (Alang-alang dengan nilai INP 37.85 tanaman tersebut adalah jenis gulma yang biasa terdapat ditempat terbuka dan terganggu.Jenis tanaman yang paling mendominasi dari kelas pohon, pancangdan tiang adalahLeucaena leucocephala(Mlandingan. Hasil analisis menunjukan Taman Kehati Unnes memiliki tumbuhan yang sangat seragam, hal ini dapat dilihat dari dominasi Mlandingan (Leucaena leucocephala

  3. Efectos de rizosfera, microorganismos y fertilización en la biorremediación y fitorremediación de suelos con petróleos crudo nuevo e intemperizado

    OpenAIRE

    Maldonado-Chávez, E; Rivera-Cruz, MC; Izquierdo-Reyes, F; Palma-López, DJ

    2010-01-01

    Se evaluó el potencial de un consorcio microbiano constituido por bacterias (Pseudomonas sp y Serratia marcescens y hongos (Aspergillus sp y Trichoderma sp) y de fertilizante inorgánico incorporados al suelo en la biorremediación, y el potencial del pasto egipto (Brachiaria mutica) y de la leguminosa guaje (Leucaena leucocephala) en la fitorremediación de un suelo contaminado con petróleos nuevo (PN) recién incorporado al suelo y el intemperizado (PI) procedente de derrames crónicos de petról...

  4. QUANTIFICAÇÃO POR CLAE DE NAFTOQUINONAS DO EXTRATO DAS RAÍZES DE Cordia leucocephala Moric.

    Directory of Open Access Journals (Sweden)

    Fernanda Maria de Oliveira

    2012-03-01

    Full Text Available Três naftoquinona, (11S, 13S, 16R-cordiaquinona J ((+-cordiaquinona J, 6-[10-(12,12-dimetil-13α-hidroxi-16-metil-ciclohexil]-1,4-naftalenodiona (cordiaquinona L e 5-metil-6-[10-(12,12-dimetil-13β-hidroxi-16ciclohexil-metil-1,4-naftalenodiona (cordiaquinona M foram isoladas do extrato etanólico das raízes de Cordia leucocephala Moric. Estas naftoquinonas, exceto a cordiaquinona M foram quantificadas por CLAE no extrato bruto das raízes de C. leucocephala. Os padrões da (+-cordiaquinona J e cordiaquinona M foram identificados no cromatograma pelos respecttivos tempo de retenção e espectro-UV. A quantificação das duas naftoquinonas apresentou teores de 310 μg de (+-cordiaquinona J e 180 μg de cordiaquinona M, em 100 mg de raízes dessa espécie vegetal.

  5. Expansión del rango de la Paloma Coroniblanca Columba leucocephala al territorio continental de Colombia

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    Moreno José Gregorio

    1999-06-01

    Full Text Available Entre las 32 especies de la familia Columbidae anotadas para Colombia, Hilty & Brown (1986 incluyeron a la Paloma Coroniblanca Columba leucocephala L. como restringida al archipiélago de San Andrés y Providencia. Esta especie, de amplia distribución en las Antillas, ha sido registrada en algunas islas continentales o localidades costeras en el sur de la Florida, Costa Rica y Panamá (Bond 1950, 1961, Wetmore 1968, Stiles & Skutch 1989. En Colombia C leucocephala fue encontrada en las islas de San Bernardo, a menos de 30 km del litoral Caribe del Departamento de Sucre (9° 40'Norte, 75° 45'Oeste en 1980 y 1981 por Moreno & López (1982, hallazgo que no fue reseñado en la literatura ornitológica de amplia circulación. En esta nota formalizamos la ampliación del rango geográfico de esta especie al territorio continental colombiano, agregando registros adicionales recientes.

  6. Nutritive value and qualitative assessment of secondary compounds in seeds of eight tropical browse, shrub and pulse legumes.

    Science.gov (United States)

    Babayemi, O J; Demeyer, D; Fievez, V

    2004-01-01

    Seeds of four tropical multipurpose trees (Albizia saman, Albizia lebbeck, Albizia rhizonse, Leucaena leucocephala), two shrubs (Tephrosia candida, Tephrosia bracteolata) and two pulse legume (Lablab purpureus, Canavalia ensiformis) were chemically analysed for dry matter (DM), ash, crude protein (CP), neutral detergent fibre (NDF) and ether extract (EE). Qualitative evaluation of secondary metabolites (saponins, phenols, steroids, and alkaloids) was elucidated. The DM, ash, CP, NDF and EE ranged between 88.9-93.6 %, 3.0-5.4 %, 24.8-38.2 %, 22.1-46.9 % and 2.0-17.0 % respectively. All seed species contained at least one group of secondary plant metabolites and steroids were common to all except C. ensiformis that was not implicated for any. A. lebbeck and A. rhizonse showed low saponin content. Indications for water soluble tannins were reported for L. leucocephala while the two species of Tephrosia contained flavonoids or condensed tannins. The study suggested the potentials of the legumes seed species as a feed source for ruminants.

  7. Effect of inclusion of different levels of silage on rumen microbial population and microbial protein synthesis in dairy steers fed on rice straw

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    Thien Truong Giang Nguyen

    2017-02-01

    Full Text Available Objective Leucaena leucocephala (Leucaena is a perennial tropical legume that can be directly grazed or harvested and offered to ruminants as hay, silage, or fresh. However, Leucaena contain phenolic compounds, which are considered anti-nutritional factors as these may reduce intake, digestibility and thus animal performance. Therefore, the objective of this experiment was to determine effects of Leucaena silage (LS feeding levels on rumen microbial populations, N-balance and microbial protein synthesis in dairy steers. Methods Four, rumen fistulated dairy steers with initial weight of 167±12 kg were randomly assigned to receive dietary treatments according to a 4×4 Latin square design. Treatments were as followings: T1 = untreated rice straw (RS; Control, T2 = 70% RS+30% LS, T3 = 40% RS+60% LS, and T4 = 100% LS. Dairy steers were fed rice straw and LS ad libitum and supplemented with concentrate at 0.2% of body weight/d. Results Results revealed that the rumen microbial population, especially cellulolytic, proteolytic bacteria and fungal zoospores were enhanced in steers that received 60% of LS (p0.05. Protozoal population was linearly decreased with increasing level of LS (p<0.05. Moreover, N-balance and microbial protein synthesis were enhanced by LS feeding (p<0.05 and were the highest in 60% LS group. Conclusion Based on this study, it could be concluded that replacement of RS with 60% LS significantly improved microbial population and microbial protein synthesis in diary steers.

  8. EFFECT OF WATER EXTRACT OF PLANTS CONTAINING TANNIN ON IN VITRO METHAGONESIS AND FERMENTATION CHARACTERISTICS OF THE GRASS Pennisetum purpureophoides

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    B. Santoso

    2013-03-01

    Full Text Available This experiment was conducted to evaluate the effect of extract of plants containing tannin on in vitro CH4 production, fermentation characteristics and nutrient degradability. Six of plant leaves i.e. Gliricidia sepium, Acacia mangium, Leucaena leucocephala, Desmodium intortum, Camellia sinensis, Calliandra calothyrsus and seed of Areca catechu were extracted by using water. Experimental treatments consisted of P. purpureophoides (300±5 mg incubated alone or added with 1.2 mL of plant extracts. The in vitro neutral detergent fibre (NDF degradability was determined using the first stage technique of Tilley and Terry. The results showed that total tannin concentration of plant extract ranged from 34 to 95 g/kg DM, and was lowest in D. intortum and highest in A. mangium. Methane production was significantly (P<0.001 lower with addition of A. mangium, L. leucocephala, A. catechu, C. sinensis and C. calothyrsus extracts compared to control. Total tannin had a close relationship with CH4 production (r=-0.79. There was strong correlation between CH4 production and NDF degradability (r=0.61. It was concluded that water extracts of A. mangium, L. leucocephala, A. catechu, C. sinensis and C. calothyrsus have potential to be used as rumen manipulator in order to reduce CH4 production in ruminants.

  9. Contrasting bee pollination in two co-occurring distylic species of Cordia (Cordiaceae, Boraginales in the Brazilian semi-arid Caatinga: generalist in C. globosa vs. specialist in C. leucocephala

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    Isabel C. Machado

    2010-12-01

    Full Text Available In this study we compare the reproductive biology of Cordia globosa and C. leucocephala (Cordiaceae, Boraginales; formerly referred to Boraginaceae to understand the functioning of the floral morphs and the relations with their effective pollinators. The species are synchronopatric, distylic, and self-incompatible. Though they share melittophilous traits, the main visitor and pollinator of C. globosa was the generalist and exotic bee Apis mellifera, while the only one of C. leucocephala was the oligoletic bee Ceblurgus longipalpis. These two latter species are restricted to the Caatinga of NE Brazil, contrasting with the wide distribution of Cordia globosa. While the fruit-set for C. globosa was high, independently if the pollen donor/stigma receptor was a pin (long-styled or thrum (short-styled individual, in C. leucocephala the fruit-set was low and occurred only when a thrum individual was the pollen donor. This raises the possibility of this species moving towards dioecy. The high natural fruit-set of C. globosa confirms the generalist bee as its effective pollinator. The low fruit-set after manual crosses in C. leucocephala may be due to low pollen viability. Additionally, the low natural fruit-set (two times lower than after crosses may be related with the foraging behavior of the specialist pollinator.Neste estudo comparamos a biologia reprodutiva de Cordia globosa e C. leucocephala para entender a função dos orfos florais e as relações com seus polinizadores efetivos. As espécies são sincronopátricas, distílicas e auto-incompatíveis. Embora elas compartilhem atributos melitófilos, o principal visitante e polinizador de C. globosa foi Apis mellifera, abelha generalista e exótica, enquanto o de C. leucocephala foi a abelha oligolética Ceblurgus longipalpis. Essas duas últimas espécies são restritas à Caatinga do Nordeste do Brasil, contrastando com a ampla distribuição de C. globosa. Enquanto a formação de frutos de C

  10. del estado de Yucatán, México

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    G. Uribe-Valle

    2007-01-01

    Full Text Available Durante 2006 en Yucatán se establecieron aproximadamente, 167,000 hectáreas con agricultura migratoria, en asociaciones de maíz con frijol, calabaza y hortalizas, en tierras con diferentes periodos de barbecho que son aprovechados por tres años. El objetivo del presente trabajo fue determinar el comportamiento químico del suelo al evaluar tres coberturas y dos periodos de barbecho, así como también la fase de cultivo. Los tipos de cobertura vegetal: Leucaena leucocephala (Lam de Wit. subespecie leucocephala, Mucuna pruriens y vegetación secundaria, con dos y cuatro años de barbecho, establecidos en un diseño de bloques al azar con cuatro repeticiones. Se determinaron los contenidos nutrimentales en tres tiempos: 1998 después de dos años de establecidos los barbechos de cuatro años, 2001 al cumplirse los barbechos de dos y cuatro años e iniciar la fase de cultivo y 2004 a tres años de uso continuo del terreno. Al final de los periodos de barbecho Leucaena mejoró en mayor medida el contenido de K, Ca y Mg, mientras que Mucuna el NO3 y la vegetación secundaria la materia orgánica. El barbecho de dos años registró valores superiores en el contenido de materia orgánica, NO3 y K, al compararlo con el de cuatro años, que superó al de dos años en el contenido de Mg.

  11. Medicina basada en la evidencia (MBE: Ventajas

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    L.M. Junquera

    2003-10-01

    Full Text Available La Medicina basada en la Evidencia (MBE se define como un proceso cuyo objetivo es la selección de los mejores argumentos científicos para la resolución de los problemas que la práctica médica cotidiana plantea. Filosóficamente es un nuevo paradigma (verificacionista, que se ha extendido a todas las profesiones sanitarias (Cirugía Basada en la Evidencia, Odontología Basada en la Evidencia, etc., soportado por los avances tecnológicos. Aunque sus ventajas son evidentes, también se han reconocido limitaciones, especialmente en lo concerniente a la práctica quirúrgica. En el presente trabajo se revisan los fundamentos y principales ventajas de la MBE.Evidence Based Medicine (EBM is defined as a process whose objective is the selection of the best scientific arguments for the resolution of problems in the medical practice. Phylosophically, it is a new paradigm that has been extended to all the sanitary professions (Evidence Based Surgery, Evidence Based Dentistry, etc., sustained by the technological advances. Although their advantages are evident, also there have been recognized limitations, specially concerning the surgical practice. At the present work the bases and the main advantages of the EBM are checked.

  12. Contrasting bee pollination in two co-occurring distylic species of Cordia (Cordiaceae, Boraginales) in the Brazilian semi-arid Caatinga: generalist in C. globosa vs. specialist in C. leucocephala.

    Science.gov (United States)

    Machado, Isabel C; Lopes, Ariadna V; Sazima, Marlies

    2010-12-01

    In this study we compare the reproductive biology of Cordia globosa and C. leucocephala (Cordiaceae, Boraginales; formerly referred to Boraginaceae) to understand the functioning of the floral morphs and the relations with their effective pollinators. The species are synchronopatric, distylic, and self-incompatible. Though they share melittophilous traits, the main visitor and pollinator of C. globosa was the generalist and exotic bee Apis mellifera, while the only one of C. leucocephala was the oligoletic bee Ceblurgus longipalpis. These two latter species are restricted to the Caatinga of NE Brazil, contrasting with the wide distribution of Cordia globosa. While the fruit-set for C. globosa was high, independently if the pollen donor/stigma receptor was a pin (long-styled) or thrum (short-styled) individual, in C. leucocephala the fruit-set was low and occurred only when a thrum individual was the pollen donor. This raises the possibility of this species moving towards dioecy. The high natural fruit-set of C. globosa confirms the generalist bee as its effective pollinator. The low fruit-set after manual crosses in C. leucocephala may be due to low pollen viability. Additionally, the low natural fruit-set (two times lower than after crosses) may be related with the foraging behavior of the specialist pollinator.

  13. Mutual reproductive dependence of distylic Cordia leucocephala (Cordiaceae) and oligolectic Ceblurgus longipalpis (Halictidae, Rophitinae) in the Caatinga.

    Science.gov (United States)

    Milet-Pinheiro, Paulo; Schlindwein, Clemens

    2010-07-01

    The close relationship between distylic Cordia leucocephala and the bee Ceblurgus longipalpis, both endemic to the Caatinga, north-east Brazil, was investigated, emphasizing reproductive dependence, morphological adaptations of the partners, and pollen flow. In the municipality of Pedra, in the Caatinga of Pernambuco, the breeding system and reproductive success of C. leucocephala, its interaction with flower visitors and inter- and intramorph pollen flow were determined. The bee Ceblurgus longipalpis, the unique flower visitor and effective pollinator of self-incompatible Cordia leucocephala, presents morphological features adapted to exploit hidden pollen and nectar in the long and narrow corolla tubes. Pollen of low-level anthers is collected with hairs on prolonged mouthparts and pollen of high-level anthers with clypeus, mandibles, and labrum, showing pollen removal from both levels with the same effectiveness. In both morphs, this results in similar legitimate, i.e. intermorph cross-pollen flow. Illegitimate pollen flow to stigmas of pin flowers, however, was much higher than to stigmas of thrum flowers. Moreover, more illegitimate pollen was transported to stigmas of pin and less to those of thrum flowers when compared with legitimate pollen flow. The study reveals a one-to-one reproductive inter-dependence between both partners. Data indicate that this relationship between bee species and plant species is one of the rare cases of monolecty among bees. Monotypic Ceblurgus longipalpis, the only rophitine species of Brazil, evolved prolonged mouthparts rare among short-tongued bees that enable them to access pollen from flowers with short-level anthers hidden for bees of other species, and nectar at the base of the flower tube.

  14. Propagação vegetativa de Hyptis leucocephala Mart. ex Benth. e Hyptis platanifolia Mart. ex Benth. (Lamiaceae Vegetative propagation of Hyptis leucocephala Mart. ex Benth. and Hyptis platanifolia Mart. ex Benth

    Directory of Open Access Journals (Sweden)

    L.M Oliveira

    2011-01-01

    Full Text Available O gênero Hyptis (Lamiaceae apresenta metabolismo especial de notável variabilidade, possuindo predominância de óleos essenciais, que têm muito valor junto a diversas comunidades que utilizam essas plantas pelas propriedades terapêuticas. Diversos estudos com esse gênero têm demonstrado que os óleos essenciais apresentam propriedades antimicrobiana, antifúngica, citotóxica, antiinflamatória, anti-HIV e inseticida, entretanto, poucos são os estudos voltados para a exploração sustentável dessas espécies. O objetivo desse trabalho foi avaliar o efeito de diferentes tipos de estaca e diferentes concentrações de ácido indolbutírico (AIB sobre a taxa de sobrevivência, crescimento e enraizamento de estacas de Hyptis leucocephala Mart. ex Benth. e Hyptis platanifolia Mart. ex Benth., espécies endêmicas do semi-árido nordestino cujo valor medicinal tem sido amplamente comprovado. O experimento teve duração de quatro meses. Foram utilizadas estacas apicais, médio-apicais, médio-basais e basais tratadas com soluções de 0, 1000, 2000 e 4000 mg L-1 de ácido indolbutírico (AIB, durante 5 minutos. A utilização de estacas apicais, médio/apicais e médio/basais induzidas com 2000 e 4000 mg L-1 de AIB possibilitaram melhores resultados para propagação vegetativa de Hyptis leucocephala. Para Hyptis platanifolia os melhores resultados foram obtidos com a utilização de estacas médio/basais e basais tratadas com AIB na concentração de 2000 e 4000 mg L-1.The genus Hyptis (Lamiaceae has a special metabolism with remarkable variability and predominance of essential oils of great value to the various communities that use these plants due to their therapeutic properties. A number of studies on this genus have demonstrated that its essential oils present antimicrobial, antifungal, cytotoxic, anti-inflammatory, anti-HIV and insecticidal activities. However, few studies have focused on the sustainable exploitation of these species

  15. Influencia de la suplementación con concentrado en la producción de leche de vacas Holstein x Cebú en silvopastoreo

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    1O. López

    Full Text Available La investigación se realizó con el objetivo de evaluar el efecto de la suplementación con concentrado en la producción y la calidad de la leche de vacas mestizas Holstein x Cebú en silvopastoreo. Se utilizaron ocho animales que pastorearon en una asociación de guinea (Panicum maximum y leucaena (Leucaena leucocephala, en un diseño Switch Back, con dos tratamientos: SS (sin suplementación y CS (0,5 kg de concentrado por kilogramo de leche producido a partir del octavo. Se midió la disponibilidad del pasto y de la leucaena, y se estimó la composición química de los alimentos. En los animales se monitoreó la condición corporal (CC, se midió la producción de leche y se determinaron las concentraciones de grasa, proteína, lactosa, sólidos totales (ST y sólidos no grasos (SNG. La disponibilidad de pasto fue 6,4 t de MS/ha/rotación, lo que, unido al ramoneo de la leucaena, permitió ofertas superiores a 100 kg de MS/animal/día. La PB de la guinea fue de 11,4 % y en la leucaena, de 25,2 %. La producción de leche del tratamiento CS fue similar a la del control (9,7 y 9,8 kg/animal/día, respectivamente, al igual que la composición de la leche (grasa, proteína, lactosa, ST y SNG y la CC de las vacas (2,70 para ambos tratamientos. Los datos sugieren que la suplementación con concentrado en vacas lecheras Holstein x Cebú, manejadas en una asociación de guinea y leucaena con elevada oferta de forraje, no incrementa la producción de leche ni mejora su calidad nutricional

  16. Arquitecturas basadas en microservicios

    OpenAIRE

    Pérez-Herrera Cuadrillero, Manuel

    2015-01-01

    En este Trabajo Fin de Grado se ha realizado un estudio sobre una nueva tendencia emergente en el desarrollo de aplicaciones web. Esta tendencia se basa en un nuevo modelo de arquitectura conocido como micro servicios. La utilización de arquitecturas basadas en micro servicios, supone un nuevo punto de vista en el desarrollo de aplicaciones web completamente diferente al que se ha estado desarrollando en los últimos años, durante los cuales las aplicaciones web se han desplegado generalmen...

  17. Wood Volume Production and Use of 10 Woody Species in Semiarid Zones of Northeastern Mexico

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    Rahim Foroughbakhch

    2012-01-01

    Full Text Available A research strategy was established to analyze the structure of timber trees in terms of forest productivity (volume and wood density of 10 species. The native species Acacia farnesiana, Acacia schaffneri, Bumelia celastrina, Cercidium macrun, Condalia hookeri, Ebenopsis ebano, Helietta parvifolia, and Prosopis laevigata and the exotic species Eucalyptus camaldulensis and Leucaena leucocephala were chosen due to their ecological and economic importance to the rural villages of northeastern Mexico. Measurements of different growth parameters and volume of trees were evaluated. The introduced species E. camaldulensis and L. leucocephala showed the best performance in wood volume production per tree and per hectare when compared to the native species. Likewise, among the native species, E. ebano, P. laevigata, C. hookeri, and A. farnesiana tended to show better characteristics in terms of wood volume production in comparison to H. parvifolia, A. schaffneri, C. macrum, and B. celastrina. Results showed a high diversity on the properties studied. The high biomass produced by most of the species considered in this study revealed their great energetic potential when used as wood and firewood or vegetal charcoal.

  18. ASOCIACIÓN DE ESPECIES LEÑOSAS EN BANCOS DE FORRAJE: INFLUENCIA SOBRE EL APORTE DE HOJARASCA, DESCOMPOSICIÓN Y LIBERACIÓN DE NITRÓGENO

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    Fernando Casanova Lugo

    2012-01-01

    Full Text Available Se evaluó el aporte de hojarasca, descomposición y liberación de N del follaje de tres especies leñosas, Leucaena leucocephala, Guazuma ulmifolia y Moringa oleifera, en bancos de forraje puros y la asociación de L. leucocephala + G. ulmifolia y L. leucocephala + M. oleifera, como bancos de forraje mixto. Se utilizaron 20 parcelas (200 m2 en un diseño de bloques completos al azar con cuatro repeticiones. La producción de hojarasca se estimó mediante el uso de trampas, instaladas en la hilera central de cada parcela. Para la descomposición se utilizaron hojas frescas de L. leucocephala, G. ulmifolia, M. oleifera, y de las mezclas de éstas. Se utilizaron 120 litter bags de 30 × 30 cm cada una, distribuidas aleatoriamente dentro de las parcelas (6 bolsas por parcela. Se retiraron 2 bolsas de cada parcela a las 4, 8 y 16 semanas. El material remanente se pesó, secó, fue molido y se determinó el contenido de N. Para determinar la constante de descomposición (k, se utilizó el modelo Y=a•e^(-k•t. El aporte de hojarasca acumulado fue diferente entre los tratamientos (P < 0.05. El banco de forraje de L. leucocephala + G. ulmifolia tuvo la mayor producción, mientras el de M. oleifera la menor. L. leucocephala, asociada con G. ulmifolia tuvo un menor aporte de hojarasca (385 kg MS ha-1, que cuando se asoció con M. oleifera o se encontraba sola (623.3 y 653.2 kg MS ha-1, respectivamente. M. oleifera asociada a L. leucocephala, incrementó su producción de hojarasca comparado con el monocultivo (124.1 vs. 58.0 kg MS ha-1. A las 4 semanas, la hojarasca de los bancos de M. oleifera, L. leucocephala y G. ulmifolia registraron una descomposición del 88, 76 y 73%, respectivamente; mientras que L. leucocephala + G. ulmifolia y L. leucocephala + M. oleifera mostraron una descomposición de 76 y 83%, respectivamente. Los bancos de forraje de M. oleifera, L. leucocephala y G. ulmifolia

  19. Enzymatic activity and mineralization of carbon and nitrogen in soil cultivated with coffee and green manures Atividade enzimática e mineralização do carbono e nitrogênio sob solo cultivado com adubos verdes na cultura do cafeeiro

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    Elcio Liborio Balota

    2010-10-01

    Full Text Available There are great concerns about degradation of agricultural soils. It has been suggested that cultivating different plant species intercropped with coffee plants can increase microbial diversity and enhance soil sustainability. The objective of this study was to evaluate enzyme activity (urease, arylsulfatase and phosphatase and alterations in C and N mineralization rates as related to different legume cover crops planted between rows of coffee plants. Soil samples were collected in a field experiment conducted for 10 years in a sandy soil in the North of Paraná State, Brazil. Samples were collected from the 0-10 cm layer, both from under the tree canopy and in-between rows in the following treatments: control, Leucaena leucocephala, Crotalaria spectabilis, Crotalaria breviflora, Mucuna pruriens, Mucuna deeringiana, Arachis hypogaea and Vigna unguiculata. The soil was sampled in four stages of legume cover crops: pre-planting (September, after planting (November, flowering stage (February and after plant residue incorporation (April, from 1997 to 1999. The green manure species influenced soil enzyme activity (urease, arylsulfatase and phosphatase and C and N mineralization rates, both under the tree canopy and in-between rows. Cultivation of Leucaena leucocephala increased acid phosphatase and arilsulfatase activity and C and N mineralization both under the tree canopy and in-between rows. Intercropped L. leucocephala increased urease activity under the tree canopy while C. breviflora increased urease activity in-between rows.Existe grande preocupação sobre a degradação dos solos agrícolas. Tem sido sugerido que o cultivo de plantas intercalares no cafeeiro aumenta a diversidade microbiana e a sustentabilidade do solo. No presente trabalho foi avaliada a alteração na atividade de enzimas do solo (urease, arilsulfatase e fosfatase e na mineralização do C e N devido ao cultivo intercalar de diferentes leguminosas de verão na cultura do

  20. Effects of Leucaena pallida and Sesbania sesban supplementation on testicular histology of tropical sheep and goats

    NARCIS (Netherlands)

    Woldemeskel, M.; Tegegne, A.; Umunna, N.N.; Kaitho, R.J.; Tamminga, S.

    2001-01-01

    Thirty Ethiopian highland rams with an average body weight of 23.7 kg (S.D.=1.23) and age of 18 months and 25 East African bucks with an average body weight of 18.6 kg (S.D.=2.06) and age of 14 months were used to study the long term effects of supplementation with the leaves of Leucaena pallida and

  1. Effects of Tropical High Tannin Non Legume and Low Tannin Legume Browse Mixtures on Fermentation Parameters and Methanogenesis Using Gas Production Technique

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    T. Seresinhe

    2012-10-01

    Full Text Available In vitro experiments were conducted to evaluate the suitability of several mixtures of high tanniniferous non legumes with low tanniniferous legumes on in vitro gas production (IVGP, dry matter degradation, Ammonia-N, methane production and microbial population. Eight treatments were examined in a randomized complete block design using four non-legumes and two legumes (Carallia integerrima×Leucaena leucocephala (LL (Trt 1, C. integerrima×Gliricidia sepium (GS (Trt 2, Aporosa lindeliyana×LL (Trt 3, A. lindeliyana×GS (Trt 4, Ceiba perntandra×LL (Trt 5, C. perntandra×GS (Trt 6, Artocarpus heterophyllus×LL (Trt 7, A. heterophyllus×GS (Trt 8. The condensed tannin (CT content of non legumes ranged from 6.2% (Carallia integerrima to 4.9% (Ceiba perntandra while the CT of legumes were 1.58% (Leucaena leucocephala and 0.78% (Gliricidia sepium. Forage mixtures contained more than 14% of crude protein (CP while the CT content ranged from 2.8% to 4.0% respectively. Differences (p0.05 NH3-N (ml/200 mg DM production was observed with the A. heterophyllus×G. sepium (Trt 8 mixture which may be attributed with it’s highest CP content. The correlation between IVGP and CT was 0.675 while IVGP and CP was 0.610. In vitro dry matter degradation (IVDMD was highest in Trt 8 as well. Methane production ranged from 2.57 to 4.79 (ml/200 mg DM to be synonimous with IVGP. A higher bacteria population (p<0.05 was found in C. perntandra×G. sepium (Trt 6 followed by Artocarpus heterophyllus+G. sepium (Trt 8 and the same trend was observed with the protozoa population as well. The results show that supplementing high tannin non leguminous forages by incremental substitution of legume forage increased gas production parameters, NH3-N, IVDMD and microbial population in the fermentation liquid. Methane production was not significantly affected by the presence of CT or different levels of CP in forage mixtures. Among non legumes, Ceiba perntandra and Artocarpus

  2. Plant growth, accumulation and solute partitioning of four forest species under salt stress Crescimento, acumulação e distribuição de solutos em espécies florestais sob estresse salino

    Directory of Open Access Journals (Sweden)

    Ricardo A. Viégas

    2003-08-01

    Full Text Available Under NaCl-salinity Na+ and Cl- accumulation of shoot and root vary greatly among glycophyte plants; this is mostly due to genetic diversity and has been utilized to distinguish between plant responses to salinity. The current study aimed to evaluate the accumulation and Na+ and Cl- tissue partitioning and its effect on dry mass gain and K+ accumulation in one-month-old Prosopis juliflora, Leucaena leucocephala, Piptadenia macrocarpa and Mimosa hostilis seedlings grown for 30 days, in sand watered with nutrient solution loading 100 mol m-3 of NaCl, in greenhouse. The Na+ and Cl- accumulation, but not partitioning between shoot and root, depended on plant species. All the plants accumulated Cl- over Na+ both in shoot and root. The K+ content of plants did not significantly vary in shoot but decreased in root due to salinity. The ability of these plants to avoid damaging the metabolism due to salinity may result, in part, from a high shoot-K+ to Na+ ratio. Leucaena leucocephala had the higher decrease of total dry matter (60% and lower shoot-K+ to Na+ ratio (0.40, while Prosopis juliflora had lower decrease of total dry matter (15% and had K+ to Na+ ratio of shoot about 3 times more. Evidence is presented supporting a role for increased K+ to Na+ ratios in adaptation of plants to osmotic and ionic stresses.Em condições de estresse salino a acumulação de Na+ e Cl-, na parte aérea e nas raízes, difere substancialmente entre plantas glicófitas; este fato deve-se, principalmente, à diversidade genética existente e tem sido utilizado como indicador da resposta das plantas à salinidade. Este estudo objetivou avaliar a acumulação e a distribuição de Na+ e Cl-, bem como o efeito da salinidade sobre o ganho de massa seca e a distribuição de K+, na parte aérea e raízes, em plantas jovens de Prosopis juliflora, Leucaena leucocephala, Piptadenia macrocarpa e Mimosa hostilis, com um mês de idade, cultivadas durante 30 dias em areia e

  3. Effect of plant and fungous metabolites on Meloidogyne exigua Efeito de metabólitos vegetais e fúngicos sobre Meloidogyne exigua

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    Daniel Rufino Amaral

    2009-01-01

    Full Text Available As nematodes cause great damage to Brazilian coffee production, effective methods to control these parasites are necessary. In a previous work Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. and Coffea arabica L. produced active substances against Meloidogyne exigua Goeldi, a nematode widely disseminated through Brazilian coffee fields. Thus, aqueous extracts of such plants, collected in a different season from that of the previous work, as well as crude metabolites produced in liquid medium by Fusarium moniliforme Shelden and Cylindrocarpon magnusianum (Sacc. Woll., were submitted to in vitro assays with M. exigua second-stage juveniles (J2. All plants and fungi produced active substances against J2. Therefore, their metabolites were applied to six-month-old coffee plants inoculated with M. exigua. After 90 days in a greenhouse, those samples obtained from A. cepa, L. leucocephala, R. graveolens and F. moniliforme inhibited the production of galls and eggs by M. exigua, demonstrating potential to control such parasite.Os nematóides acarretam grandes perdas aos produtores brasileiros de café, sendo necessário o desenvolvimento de métodos eficientes para o seu controle. Em trabalho anterior, Allium cepa L., Cajanus cajan (L. Mill., Crotalaria juncea L., Ficus elastica Roxb., Ruta graveolens L., Stylosanthes guianensis Aubl., Leucaena leucocephala (Lam. Dewit., Brachiaria decumbens Stapf., Catharanthus roseus G. Don, Tagetes minuta L., Ricinus communis L. e Coffea arabica L. produziram substâncias ativas contra o nematóide Meloidogyne exigua Goeldi, que é amplamente disseminado pelos cafezais brasileiros. Dando continuidade a esse trabalho, extratos aquosos das plantas mencionadas, coletadas em época diferente daquela

  4. Phylogenetic and population genetic analyses of diploid Leucaena (Leguminosae; Mimosoideae) reveal cryptic species diversity and patterns of divergent allopatric speciation.

    Science.gov (United States)

    Govindarajulu, Rajanikanth; Hughes, Colin E; Bailey, C Donovan

    2011-12-01

    Leucaena comprises 17 diploid species, five tetraploid species, and a complex series of hybrids whose evolutionary histories have been influenced by human seed translocation, cultivation, and subsequent spontaneous hybridization. Here we investigated patterns of evolutionary divergence among diploid Leucaena through comprehensively sampled multilocus phylogenetic and population genetic approaches to address species delimitation, interspecific relationships, hybridization, and the predominant mode of speciation among diploids. Parsimony- and maximum-likelihood-based phylogenetic approaches were applied to 59 accessions sequenced for six SCAR-based nuclear loci, nrDNA ITS, and four cpDNA regions. Population genetic comparisons included 1215 AFLP loci representing 42 populations and 424 individuals. Phylogenetic results provided a well-resolved hypothesis of divergent species relationships, recovering previously recognized clades of diploids as well as newly resolved relationships. Phylogenetic and population genetic assessments identified two cryptic species that are consistent with geography and morphology. Findings from this study highlight the importance and utility of multilocus data in the recovery of complex evolutionary histories. The results are consistent with allopatric divergence representing the predominant mode of speciation among diploid Leucaena. These findings contrast with the potential hybrid origin of several tetraploid species and highlight the importance of human translocation of seed to the origin of these tetraploids. The recognition of one previously unrecognized species (L. cruziana) and the elevation of another taxon (L. collinsii subsp. zacapana) to specific status (L. zacapana) is consistent with a growing number of newly diagnosed species from neotropical seasonally dry forests, suggesting these communities harbor greater species diversity than previously recognized.

  5. Leucaena and cassava tops as supplements for buffaloes fed local grass

    International Nuclear Information System (INIS)

    Hendratno, C.; Abidin, Z.; Suharyono; Bahauddin, R.; Yates, N.G.; Winogroho, M.

    1984-01-01

    Experiments were conducted using fistulated female buffaloes to determine the effect of increasing levels of high-protein forage (leucaena and cassava tops) on the intake of grass and its digestibility, and to study the mechanisms of action of such supplements based on measurements of a number of parameters of rumen function. Marked increases in intake were observed and these were associated with increases in the digestibility of diets supplemented with these forages. These responses were accompanied by increased rumen fermentation as indicated by ammonia-N and volatile fatty acid concentrations, and rates of microbial protein synthesis. The results suggest that local grass requires supplementation with fermentable N and bypass protein for efficient use by ruminants. (author)

  6. Caracterización de especies arbóreas y arbustivas forrajeras en clima semiárido del sur de Mozambique

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    E Cordoví

    Full Text Available Con el objetivo de caracterizar el comportamiento de especies forrajeras arbóreas y arbustivas en clima semiárido se desarrolló un experimento, con corte y en secano, con Gliricidia sepium, Leucaena leucocephala, Leucaena pallida, Moringa oleifera, Senna siamea y Morus alba. El diseño fue de bloques al azar, con cuatro réplicas, y se utilizaron parcelas de 12 m². En verano, L. leucocephala, L. pallida, S. siamea y M. alba produjeron más de 12 t de MS por hectárea como promedio; mientras que en invierno se obtuvieron entre 9,38 y 11,62 t/ha, excepto en M. oleifera (5,49 t/ha. Los intervalos de corte variaron entre 62 y 65 días en verano; mientras que en invierno aumentaron hasta 102 y 117 días en G. sepium y M. oleifera, respectivamente, y oscilaron entre 81 y 92 días para el resto de las especies. El porcentaje de hojas fue superior en invierno y en ello sobresalió S. siamea (62 y 69 % en verano e invierno, respectivamente. Durante el invierno se obtuvo una alta producción de MS, en lo cual se destacaron G. sepium, M. alba y S. siamea (47-50 %. Se confirmó el buen comportamiento de estas especies arbóreas y arbustivas en condiciones semiáridas, con rendimientos de MS superiores a 12 t/ha y una producción estable durante el año. Se recomienda incluirlas en investigaciones con animales en sistemas silvopastoriles y bancos de proteína; así como utilizar otros marcos de siembra en función de mejorar su potencial productivo

  7. Application of poultry processing industry waste: a strategy for vegetation growth in degraded soil.

    Science.gov (United States)

    do Nascimento, Carla Danielle Vasconcelos; Pontes Filho, Roberto Albuquerque; Artur, Adriana Guirado; Costa, Mirian Cristina Gomes

    2015-02-01

    The disposal of poultry processing industry waste into the environment without proper care, can cause contamination. Agricultural monitored application is an alternative for disposal, considering its high amount of organic matter and its potential as a soil fertilizer. This study aimed to evaluate the potential of poultry processing industry waste to improve the conditions of a degraded soil from a desertification hotspot, contributing to leguminous tree seedlings growth. The study was carried out under greenhouse conditions in a randomized blocks design and a 4 × 2 factorial scheme with five replicates. The treatments featured four amounts of poultry processing industry waste (D1 = control 0 kg ha(-1); D2 = 1020.41 kg ha(-1); D3 = 2040.82 kg ha(-1); D4 = 4081.63 kg ha(-1)) and two leguminous tree species (Mimosa caesalpiniaefolia Benth and Leucaena leucocephala (Lam.) de Wit). The poultry processing industry waste was composed of poultry blood, grease, excrements and substances from the digestive system. Plant height, biomass production, plant nutrient accumulation and soil organic carbon were measured forty days after waste application. Leguminous tree seedlings growth was increased by waste amounts, especially M. caesalpiniaefolia Benth, with height increment of 29.5 cm for the waste amount of 1625 kg ha(-1), and L. leucocephala (Lam.) de Wit, with maximum height increment of 20 cm for the waste amount of 3814.3 kg ha(-1). M. caesalpiniaefolia Benth had greater initial growth, as well as greater biomass and nutrient accumulation compared with L. leucocephala (Lam.) de Wit. However, belowground biomass was similar between the evaluated species, resulting in higher root/shoot ratio for L. leucocephala (Lam.) de Wit. Soil organic carbon did not show significant response to waste amounts, but it did to leguminous tree seedlings growth, especially L. leucocephala (Lam.) de Wit. Poultry processing industry waste contributes to leguminous tree seedlings growth

  8. Interaction of vesicular-arbuscular mycorrhizal fungi with erosion in an oxisol.

    Science.gov (United States)

    Habte, M; Fox, R L; Aziz, T; El-Swaify, S A

    1988-04-01

    The development of vesicular-arbuscular mycorrhizal (VAM) symbiosis was monitored in Leucaena leucocephala grown in an Oxisol subjected to incremental simulated erosion. The density of VAM infective propagules in the soil diminished as the level of simulated erosion (removal of surface soil) was increased from 0 to 50 cm. The level of infection on L. leucocephala roots observed at harvest was not significantly influenced by simulated erosion unless removal of surface soil exceeded 25 cm. Inoculation of this soil and the uneroded soil with Glomus aggregatum enhanced the early onset of infection but did not significantly influence the level of infection observed at the time of harvest. Simulated erosion in excess of 7.5 cm of surface soil removal significantly delayed the development of VAM effectiveness monitored in terms of the P status of L. leucocephala subleaflets and also curtailed the level of maximum effectiveness observed. Decreases in VAM effectiveness were significantly correlated with decreases in soil chemical constituents. However, VAM effectiveness in a soil subjected to 30 cm of surface soil removal was not restored to a significant extent unless the soil was amended with P, even though other nutrients were restored to sufficiency levels. Our results demonstrate that the development of VAM effectiveness is the phase of the VAM symbiosis that is most adversely influenced by simulated erosion and that this effect appears to be caused primarily by insufficient P in the soil solution.

  9. 1H and 13C NMR assignments for two new cordiaquinones from roots of Cordia leucocephala.

    Science.gov (United States)

    Diniz, Jaécio Carlos; Viana, Francisco Arnaldo; Oliveira, Odaci Fernandes; Maciel, Maria Aparecida M; Torres, Maria da Conceição de Menezes; Braz-Filho, Raimundo; Silveira, Edilberto R; Pessoa, Otília Deusdênia L

    2009-02-01

    From the roots of Cordia leucocephala (Boraginaceae), two new meroterpenoid naphthoquinones, 6-[10-(12,12-dimethyl-13alpha-hydroxy-16-methenyl-cyclohexyl)ethyl]-1,4-naphthalenedione (cordiaquinone L) and 5-methyl-6-[10-(12,12-dimethyl-13beta-hydroxy-16-methenyl-cyclohexyl)methyl-1,4-naphthalenedione (cordiaquinone M) were isolated. Their structures were elucidated after detailed 1D and 2D NMR (COSY, HSQC, HMBC and NOESY) data analyses and comparison with literature data for analogous compounds. 2008 John Wiley & Sons, Ltd.

  10. First report of Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Lecanodiaspididae and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae in Brazil

    Directory of Open Access Journals (Sweden)

    A. L. Marsaro Júnior

    Full Text Available Abstract Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Coccoidea: Lecanodiaspididae and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae are reported for the first time in Brazil. Specimens of this scale insect were collected on branches and stems of Acacia mangium Willd., Leucaena leucocephala (Lam. de Wit (Fabaceae, Morus nigra L. (Moraceae, Citrus reticulata Blanco (Rutaceae, Tectona grandis L. f. (Verbenaceae, Anacardium occidentale (Anacardiaceae, Annona squamosa L. and Xylopia aromatica (Lam. Mart. (Annonaceae, in three municipalities of the Roraima state. All plants here mentioned are recorded for the first time as a host for L. dendrobii. Morphological characters of L. dendrobii and symptoms presented by the host plants infested by this pest are included in this work.

  11. First report of Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Lecanodiaspididae) and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae) in Brazil.

    Science.gov (United States)

    Marsaro Júnior, A L; Peronti, A L B G; Costa, V A; Morais, E G F; Pereira, P R V S

    2016-02-01

    Lecanodiaspis dendrobii Douglas, 1892 (Hemiptera: Coccoidea: Lecanodiaspididae) and the associated parasitoid Cephaleta sp. (Hymenoptera: Pteromalidae) are reported for the first time in Brazil. Specimens of this scale insect were collected on branches and stems of Acacia mangium Willd., Leucaena leucocephala (Lam.) de Wit (Fabaceae), Morus nigra L. (Moraceae), Citrus reticulata Blanco (Rutaceae), Tectona grandis L. f. (Verbenaceae), Anacardium occidentale (Anacardiaceae), Annona squamosa L. and Xylopia aromatica (Lam.) Mart. (Annonaceae), in three municipalities of the Roraima state. All plants here mentioned are recorded for the first time as a host for L. dendrobii. Morphological characters of L. dendrobii and symptoms presented by the host plants infested by this pest are included in this work.

  12. Phylogenetic relationships and host range of Rhizobium spp. that nodulate Phaseolus vulgaris L.

    Science.gov (United States)

    Hernandez-Lucas, I; Segovia, L; Martinez-Romero, E; Pueppke, S G

    1995-07-01

    We determined the nucleotide sequences of 16S rRNA gene segments from five Rhizobium strains that have been isolated from tropical legume species. All share the capacity to nodulate Phaseolus vulgaris L., the common bean. Phylogenetic analysis confirmed that these strains are of two different chromosomal lineages. We defined the host ranges of two strains of Rhizobium etli and three strains of R. tropici, comparing them with those of the two most divergently related new strains. Twenty-two of the 43 tested legume species were nodulated by three or more of these strains. All seven strains have broad host ranges that include woody species such as Albizia lebbeck, Gliricidia maculata, and Leucaena leucocephala.

  13. Avaliação da produtividade de fitomassa e acúmulo de N, P e K em leguminosas arbóreas no sistema de aléias, em Campos dos Goytacazes, RJ Evaluation of phytomass productivity and N, P and K accumulation of shrub legumes in alley cropping system in Campos dos Goytacazes (RJ

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    Luciano Rodrigues Queiroz

    2007-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a produtividade de fitomassa da parte aérea e o acúmulo de N, P e K nas leguminosas arbóreas em sistemas agroflorestais de aléias, bem como verificar o efeito da adição de fósforo sobre as leguminosas. Foram realizados experimentos de campo com a utilização de leguminosas, com e sem adição de P, por dois anos consecutivos de avaliação, em Campos dos Goytacazes,RJ. Os tratamentos consistiram do sistema de aléias com Albizia lebbeck (L. Benth., Peltophorum dubium (Spreng. Taub., Leucaena leucocephala (Lam. de Wit., Cajanus cajan (L. Millsp., Sesbania virgata (Cav. Pers., Mimosa caesalpiniaefolia Benth. e Gliricidia sepium (Jacq. Pers. Após oito meses de plantio das leguminosas, estas foram podadas a 1,5 m de altura, restando a haste principal. O material podado foi pesado, descartando-se os ramos com diâmetro superior a 1,5 cm e sendo retiradas as amostras compostas para determinações da fitomassa seca e dos teores de N, P e K. Efetuou-se nova poda 80 dias após a primeira, e pesou-se esse material. No primeiro ano, o guandu mostrou-se superior na produtividade de fitomassa seca e no acúmulo de N, P e K. No segundo ano de avaliação, no experimento com adição de P a leucena e a canafístula assemelharam-se ao guandu na produtividade de fitomassa, enquanto a leucena e o guandu, no acúmulo de N e P, porém a leucena superou o guandu e a canafístula no acúmulo de K na parte aérea. A aplicação de P teve efeito positivo na produtividade de fitomassa seca de algumas espécies.The objective of this study was to evaluate the shoot phytomass and shrub legumes N, P and K accumulation in agroforestry system (alley cropping system and study the effect of P fertilization. Two field experiments were carried out - without and with P application - for two years: 2004 and 2005, using shrub legumes in Campos dos Goytacazes - RJ - Brazil. The treatments consisted of alley cropping system with the

  14. Growth and Nitrogen Uptake in Sorghum Plants Manured with Leucaena Leucocaphala Leaves as Affected by Nitrogen Rate and Time of Application

    International Nuclear Information System (INIS)

    Kurd Ali, F.; Al-Shammaa, M.

    2011-01-01

    A pot experiment was conducted to determine the effect of four rates of nitrogen (N) in the form of leucaena leaves and the time of application on the performance of sorghum plants using the 15 N isotopic dilution technique. Results showed that leucaena green manure (LGM) increased dry matter and N yield of sorghum. Nitrogen recoveries of LGM ranged between 23 and 47%. An additional beneficial effect of LGM was attributed to the enhancement of soil N uptake. The best timing of LGM incorporation for obtaining more N derived from LGM, less soil N uptake, and greater dry matter and N in sorghum leaves seemed to be at planting. However, the appropriate timing and rate of LGM to obtain greater dry matter and N yield in panicles, as well as in the whole plant of sorghum, appeared to be at 30 days before planting, particularly a rate of 120 kg N ha - 1. (author)

  15. Chemical composition and ruminal degradation kinetics of crude protein and amino acids, and intestinal digestibility of amino acids from tropical forages

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    Lidia Ferreira Miranda

    2012-03-01

    Full Text Available The objective of this research was to determine the chemical composition and ruminal degradation of the crude protein (CP, total and individual amino acids of leaves from tropical forages: perennial soybean (Neonotonia wightii, cassava (Manihot esculenta, leucaena (Leucaena leucocephala and ramie (Boehmeria nivea, and to estimate the intestinal digestibility of the rumen undegradable protein (RUDP and individual amino acids of leaves from the tropical forages above cited, but including pigeon pea (Cajanus cajan. Three nonlactating Holstein cows were used to determine the in situ ruminal degradability of protein and amino acids from leaves (6, 18 and 48 hours of ruminal incubation. For determination of the intestinal digestibility of RUDP, the residue from ruminal incubation of the materials was used for 18 hours. A larger concentration of total amino acids for ramie and smaller for perennial soybean were observed; however, they were very similar in leucaena and cassava. Leucine was the essential amino acid of greater concentration, with the exception of cassava, which exhibited a leucine concentration 40.45% smaller. Ramie showed 14.35 and 22.31% more lysine and methionine, respectively. The intestinal digestibility of RUDP varied from 23.56; 47.87; 23.48; 25.69 and 10.86% for leucaena, perennial soybean, cassava, ramie and pigeon pea, respectively. The individual amino acids of tropical forage disappeared in different extensions in the rumen. For the correct evaluation of those forages, one should consider their composition of amino acids, degradations and intestinal digestibility, once the amino acid composition of the forage does not reflect the amino acid profiles that arrived in the small intestine. Differences between the degradation curves of CP and amino acids indicate that degradation of amino acids cannot be estimated through the degradation curve of CP, and that amino acids are not degraded in a similar degradation profile.

  16. Case studies related to the management of soil acidity and infertility in the West-African Moist Savannah

    International Nuclear Information System (INIS)

    Vanlauwe, B.; Sanginga, N.; Diels, J.; Merckx, R.

    2006-01-01

    Although the soil pH and base status of the soils in the West African Moist Savannah Zone (MSZ) are usually favourable, their buffer capacity is usually low, indicating that while soil acidity may not be a problem initially, inappropriate management of these soils may induce soil-acidity-related problems in the medium to long term. The current paper addresses 3 topics that are closely related to the management of soil pH (acidity) in the West African MSZ. A first experiment addressed the release of P from low reactivity phosphate rock (PR) by mixing it with various N fertilizers. Mixing ammonium-sulphate, urea, and calcium-ammonium nitrate with PR substantially enhanced the soil Olsen-P content, but not for soils with an initial pH above 5.5, while potassium nitrate did not change the Olsen-P content. Changes in soil pH could be predicted based on the production of nitrate from ammonium (nitrification) and the soil buffer capacity. A second experiment examined the changes in topsoil pH as affected by long term management based on the application of organic inputs derived from hedgerow trees (Leucaena leucocephala and Senna siamea), fertilizer, or both. Maize crop yields declined steadily over the 16 years studied, but the least so in the Senna + fertilizer treatment where in 2002 still 2.2 t ha -1 of maize were obtained. The fertilizer only treatment led to a yield of 0.4 t ha -1 in 2002, while the absolute control without any inputs yielded a mere 40 kg ha -1 in the same year. Nitrogen fertilizer use efficiency was usually higher in the Senna treatment compared to the control or the Leucaena treatment. Interactions between fertilizer and organic matter additions were negative for the Leucaena treatments in the first three years, and positive for the Senna treatment in the last 6 years. Trees had a positive effect on the maintenance of exchangeable cations in the topsoil. Exchangeable Ca, Mg and K - and hence ECEC - were only slightly reduced after 16 years of

  17. Medicina basada en la evidencia.

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    José Félix Patiño Restrepo

    1999-08-01

    Full Text Available

    El concepto de Medicina Basada en la Evidencia fue descrito en la Universidad de McMaster en el Canadá, como una nueva manera de enseñar y de practicar medicina. Pero fue en la Universidad de Oxford donde se hicieron los primeros planteamientos por el epidemiólogo Archie Cochrane, quien afirmó la necesidad de disponer de revisiones sistemáticas de los estudios prospectivos y randomizados en el campo de la atención medica. La Cochrane Collaboration, la Cochrane Network y la Cochrane Library constituyen una formidable organización internacional sin ánimo de lucro destinada a proveer información sistematizada sobre resultados de estudios prospectivos y controlados como fundamento para una atención de la salud de alta calidad.

    La medicina basada en la evidencia integra la mejor evidencia científica disponible con la experiencia y la habilidad clínica, con el conocimiento de la fisiopatología y con las preferencias de los pacientes, para una toma de decisiones fundamentada en datos e información cuya veracidad y exactitud estén rigurosamente comprobados, o sea una práctica médica basada en los resultados de investigación científica de la mejor calidad. La mejor evidencia científica surge de ensayos prospectivos y rigurosamente controlados, los estudios clínicos randomizados* (ECR, que también se conocen como estudios clínicos controlados (ECC.

    El concepto de medicina basada en la evidencia ha llevado al desarrollo de guías de práctica clínica, cuyo objetivo es objetivo es la estandarización de conductas a fin de minimizar variaciones en los patrones de la práctica médica, reducir la mala calidad de la atención, controlar diferencias geográficas en los patrones del ejercicio profesional y racionalizar costos. La Asociación Médica Americana prefiere la denominación “parámetros de práctica clínica”.

    El concepto de medicina basada en la evidencia fue descrito en forma clásica en la

  18. Comparación de tres leguminosas arbóreas sembradas en un sustrato alcalino durante el período de aviveramiento. II. Patrón de crecimiento y distribución de la biomasa Comparison of three tree legumes planted on an alkaline substratum during the nursery stage. II. Growth and biomass distribution pattern

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    María G Medina¹

    2011-06-01

    Full Text Available Se desarrolló un experimento en el estado Trujillo, Venezuela, con el objetivo de comparar el patrón de crecimiento y la distribución de biomasa de Albizia lebbeck, Leucaena leucocephala (ecotipo Trujillo y Erythrina fusca durante 18 semanas en vivero. Las variables estudiadas fueron: tasa de crecimiento en función de la altura (TCA y de la distribución de la MS (TCMS, así como el porcentaje de materia seca (MS y el peso seco por planta de las fracciones (hojas, tallo, raíz. Se utilizó un diseño completamente aleatorizado para mediciones repetidas en el tiempo y diez réplicas por especie. Erythrina presentó la mayor TCA y TCMS promedio (3,7 mm/día y 94,8 mg/día, seguida por leucaena (3,1 y 81,3 y, por último, albizia (1,2 mm/día y 53,1 mg/día, respectivamente. Independientemente de la especie, el mayor porcentaje de MS promedio se observó en las raíces (31,9, seguido por el tallo (28,0 y las hojas (25,4. Se observó una mayor distribución de MS por planta en las hojas (3,9 g y la raíz (3,1 g, comparados con el tallo (2,9 g. Se concluye que, para estas condiciones de aviveramiento, E. fusca presentó los mejores resultados; mientras que A. lebbeck necesitaría más tiempo para alcanzar las características deseables para su trasplante a campo.A trial was conducted in the Trujillo state, Venezuela, in order to compare the growth and biomass distribution pattern of Albizia lebbeck, Leucaena leucocephala (Trujillo ecotype and Erythrina fusca for 18 weeks in nursery. The studied variables were: growth rate related to height (GRH and DM distribution (GRDM, as well as dry matter percentage (DM and dry weight per plant of the fractions (leaves, stem, root. A completely randomized design for measurements repeated in time and ten replications per species were used. E. fusca showed the highest average GRH and GRDM (3,7 mm/day and 94,8 mg/day, followed by L. leucocephala (3,1 and 81,3 and, lastly, A. lebbeck (1,2 mm/day and 53,1 mg

  19. Status of industrial pollution and their effect on seed germination and growth performance of albizia lebbek (benth.) and leucaena leucocephala (LAM) de wit

    International Nuclear Information System (INIS)

    Shiuli, M.D.; Alam, S.; Mohiuddin, M.M.

    2005-01-01

    contamination than in soil contaminated with effluents of tanneries (57%, 11.91 cm, 2.97 cm, 7.5 gm and 25, respectively) textiles (53%, 13.99 cm, 3.2 cm, 6.5 gm and 28, respectively) and fisheries (60%, 13.35 cm, 3.66 cm, 5 gm and 31, respectively). The soils contaminated by the effluents of textiles and fisheries has positive influence on the seed germination and growth performance of leaucaena leucocephala. In this case, seed germination, height growth, collar diameter. Total biomass and nodule numbers were 97%. 24.33 cm, 2.8 mm, 8.8 gm and 67 respectively in soils contaminated with effluents of textiles and fisheries (96%, 23.42 cm, 23.42 cm, 2.6 mm, 9.13 gm and 62 respectively) as compared to that of control soils (95%, 19.3 cm, 2.0 mm, 8.23 gm and 54, respectively) and contaminated soils of tanneries effluents (95%, 19.7 cm, 1.7 mm, 6.8 gm and 39, respectively). These indicate that the response of different tree species to similar pollution prone area could be different. (author)

  20. Sustainable Milk and Meat Production while Reducing Methane Emissions from Livestock Enteric Fermentation

    Science.gov (United States)

    Castelan-Ortega, O. A.; Molina, L. T.; Pedraza-Beltrán, P. E.; Hernández-Pineda, G.; Ku-Vera, J. C.; Benaouda, M.; Gonzalez-Ronquillo, M.

    2016-12-01

    Ruminants produce all the milk and most of the meat demanded by humans; however, ruminant production generates large quantities of greenhouse gases (GHG), around 15% of anthropogenic emissions of GHG are attributed to ruminant production. Therefore there is an urgent need to develop sustainable alternatives to mitigate GHG emissions by ruminants and to increase the supply of high quality protein for human consumption in a climate change scenario. The objective of this work is to present sustainable options to mitigate methane (CH4) production from enteric fermentation by cattle and to illustrate how productivity can be increased at the same time. We conducted several experiments to measure CH4 emission in vivo by cattle in order to estimate emission factors in the temperate and tropical climate regions of Mexico followed by inventory calculation. We then evaluated the supplementation to cattle of different tanniferous plants to reduce enteric CH4 formation and finally established two mitigation scenarios for each region. Leucaena leucocephala and Cosmos bipinnatus are the tanniferous plants that produced the largest reduction in CH4 formation. In scenario 1, a moderate mitigation scenario, it was assumed 16% reduction of enteric CH4 emission in the temperate climate regions (TEMP) and 36% in the tropical regions (TROP) with cattle population of 37.8 million heads, from which 22.3 are in the TEMP (emission factor 529 l/day/head) and 15.5 in the TROP (emission factor 137 l/day/head). Reduction potential resulting from the use of C. bipinnatus and L. Leucocephala over a year is 1,203Gg. In scenario 2, a high mitigation situation, it was assumed a 26% reduction of CH4 emission in the TEMP and 36% in the TROP and the same cattle population. The reduction potential resulting from C. bipinnatus and L. Leucocephala use in a year is 1,512 Gg. Results showed that in both scenarios the CH4 released by enteric fermentation could be reduced by the use of the plants evaluated

  1. Founded: Genetic Reconstruction of Lineage Diversity and Kinship Informs Ex situ Conservation of Cuban Amazon Parrots (Amazona leucocephala).

    Science.gov (United States)

    Milián-García, Yoamel; Jensen, Evelyn L; Madsen, Jeanette; Álvarez Alonso, Suleiky; Serrano Rodríguez, Aryamne; Espinosa López, Georgina; Russello, Michael A

    2015-01-01

    Captive breeding is a widespread conservation strategy, yet such programs rarely include empirical genetic data for assessing management assumptions and meeting conservation goals. Cuban Amazon parrots (Amazona leucocephala) are considered vulnerable, and multiple on-island captive populations have been established from wild-caught and confiscated individuals of unknown ancestry. Here, we used mitochondrial haplotypic and nuclear genotypic data at 9 microsatellite loci to quantify the extent and distribution of genetic variation within and among captive populations in Zapata Swamp and Managua, Cuba, and to estimate kinship among breeders (n = 88). Using Bayesian clustering analysis, we detected 2 distinct clusters within the Zapata population, one of which was shared with Managua. Individuals from the cluster unique to Zapata possessed mitochondrial haplotypes with affinities to Cuban subspecies (A. l. leucocephala, A. l. palmarum); the shared cluster was similar, but also included haplotypes closely related to the subspecies restricted to Cayman Brac (A. l. hesterna). Overall mean kinship was low within each captive population (-0.026 to -0.012), with 19 and 11 recommended breeding pairs in Zapata and Managua, respectively, ranked according to mean kinship and informed by molecular sexing. Our results highlight the importance of understanding population history within ex situ management programs, while providing genetic information to directly inform Cuban parrot conservation. © The American Genetic Association 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  2. Assessing the sustainable development and intensification potential of beef cattle production in Sumbawa, Indonesia, using a system dynamics approach.

    Science.gov (United States)

    Dahlanuddin; Henderson, Benjamin; Dizyee, Kanar; Hermansyah; Ash, Andrew

    2017-01-01

    The intensification of beef cattle production in dryland areas of East Indonesia has the potential to substantially raise the incomes of smallholder farmers that dominate the sector. In this study we assess the potential for intensifying beef production on Sumbawa Island, by introducing a household feedlot production system (2-20 animals) based on the Leucaena leucocephala (leucanea) tree legume as an improved source of feed. We used a system dynamics approach to model the entire value chain, accounting for herd dynamics, demand dynamics and seasonality. Our findings complement the growing body of biophysical evidence about the potential success of this intervention, by simulating improvements in the annual profitability for beef farmers in the project area of up to 415% by 2023. Increases in farm profit were shown to depend near equally on the higher productivity of the leucaena feeding system and an associated price premium, demonstrating the importance of supporting improved agricultural production with better marketing practices. The intervention was also shown to generate positive or neutral benefits for the main post-farm value chain actors. Importantly, it also reduced the GHG emission intensity of outputs from the beef herd by 16% by 2020. We explored number of scale-out pathways, including a relatively moderate pace of autonomous adoption for our main analysis, resulting in the accumulation of 3,444 hectares of leucaena 20-years after the initial project phase, which could sustain the fattening of 37,124 male cattle per year. More ambitious rates of scale-out were found to be possible without exceeding the animal and land resources of the island.

  3. ENERGETIC VALUE OF FORAGES FROM SEMI-ARID REGION AND DIGESTIBILITY OF RATIONS FOR NAKED NECK PULLETS

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    ALEX MARTINS VARELA DE ARRUDA

    2014-01-01

    Full Text Available The feeding programs for naked neck chickens in semi-intensive production system from brazilian equatorial semi-arid environment, must consider regional food availability and respective nutritional values. Thus, to evaluate the digestibility and metabolizable energy of alternative forages, it was used 240 naked neck pullets (Isa Label lineage receiving water and ration ad libitum, pair-housed in cages for total collection of excreta on conventional warehouse. It was used a completely randomized design with factorial arrangement (5x2: one control ration (corn and soy meal and other four experimental rations with silk flower hay (Calotropis procera, cassava leafs hay (Manihot esculenta, kills pasture hay (Senna obtusifolia or leucaena leafs hay (Leucaena leucocephala, and all rations were balanced for two growing phases, between 8 and 10 weeks (young pullets and between 14 and 16 weeks of age (old pullets. The values of apparent digestibility of nutrients for all experimental rations were lower than control ration (P <0.05 and it was observed general means of 72.18% for dry matter, 78.12% for crude protein, 66.90% for ether extract, 28.08% for neutral detergent fiber, 18.51% for the acid detergent fiber, 71.64% for gross energy and availability of 15.61% for mineral matter. The general mean of apparent and corrected metabolizable energy of alternative forages was 1217 kcal/ kg and 1108 kcal/kg, respectively, and the higher value was determined for leucaena hay and the lower value for silk flower hay (P <0.05.

  4. Effect of Leucaena and Sesbania supplementation on body growth and scrotal circumference of Ethiopian highland sheep and goats fed teff straw basal diet

    NARCIS (Netherlands)

    Kaitho, R.J.; Tegegne, A.; Umunna, N.N.; Nsahlai, I.V.; Tamminga, S.; Bruchem, J. van; Arts, J.M.

    1998-01-01

    The long term effect of supplementation of Leucaena pallida and Sesbania sesban on growth and reproduction performance was determined on 30 male Ethiopian highland sheep and 25 East African goats. Unchopped teff straw (Eragrostis tef) was given ad libitum and supplemented with either wheat bran (150

  5. Depresión posparto: ¿se encuentra asociada a la violencia basada en género?

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    Juan Escobar

    2009-06-01

    Full Text Available Introducción: La depresión posparto y la violencia basada en género son patologías muy frecuentes en la mujer; la importancia de un diagnóstico y tratamiento oportuno radica en evitar las consecuencias a futuro en la mujer, el recién nacido y la familia en general. Objetivos: Determinar la asociación entre depresión posparto y la violencia basada en género. Diseño: Exploratorio, de corte transversal. Lugar: Hospital Nacional Docente Madre Niño San Bartolomé, Lima, Perú. Participantes: Mujeres puérperas. Intervenciones: Se aplicó una ficha de datos sociodemográficos y del parto, la escala de Edimburgo, el inventario revisado de factores predictores de depresión posparto y el instrumento de detección de violencia basada en género a 100 mujeres, de 1 a 12 meses de tiempo puerperal. Principales medidas de resultados: Asociación entre depresión posparto y violencia basada en género. Resultados: La tasa de depresión posparto fue 17%, encontrando diferencias estadísticas al compararla con autoestima, depresión previa al embarazo, ansiedad durante la gestación, satisfacción marital y eventos estresantes durante la gestación. El 51% fue víctima de violencia basada en género, siendo la más frecuente la forma psicológica. Se halló diferencias estadísticas entre depresión posparto y violencia basada en género (p=0,001, así como, diferencias estadísticas entre depresión posparto y violencia durante la gestación, encontrando un OR de 5,5 (IC: . Conclusiones: Las mujeres víctimas de violencia tienen riesgo elevado de sufrir depresión posparto.

  6. Comportamiento de la disponibilidad de biomasa y la composición química en 23 accesiones de Leucaena spp. Performance of biomass availability and chemical composition of 23 Leucaena spp. accessions

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    Hilda B Wencomo

    2012-03-01

    Full Text Available Se realizó un estudio con 23 accesiones de Leucaena spp. en un área que tenía seis años de sembrada. El objetivo fue determinar, en las plantas establecidas, la biomasa total, la biomasa comestible, la biomasa leñosa, el grosor del tallo y el número de ramas de cada accesión, y su composición bromatológica en condiciones de pastoreo simulado. La investigación se realizó en la EEPF "Indio Hatuey" durante dos años, en un suelo Ferralítico Rojo lixiviado, húmico nodular ferruginoso hidratado. Se utilizaron parcelas sencillas de 3 m x 6 m. En la biomasa comestible y sus componentes (hojas y tallos tiernos existieron diferencias significativas (PA study was conducted with 23 Leucaena spp. accessions in an area which had been planted six years before. The objective was to determine, in the established plants, total biomass, edible biomass, ligneous biomass, stem diameter and number of branches in each accession, and its bromatological composition under simulated grazing conditions. The research was conducted at the EEPF "Indio Hatuey" during two years, on a hydrated ferruginous nodular humic lixiviated Ferralitic Red soil. Simple 3 m x 6 m plots were used. In the edible biomass and its components (leaves and fresh stems, there were significant differences (P<0,05 between the seasons of the two years. It could be observed that production was higher in the rainy season than in the dry season, although there were no differences among the mean biomass production of the accessions; in the case of total biomass no significant differences were found between seasons. To continue the studies is recommended, to determine, in the long term, the effect of the evaluated indicators on the availability and persistence of the tree.

  7. Calidad nutricional y fraccionamiento de carbohidratos y proteína en los componentes forrajeros de un sistema silvopastoril intensivo

    Directory of Open Access Journals (Sweden)

    Xiomara Gaviria

    Full Text Available El objetivo de esta investigación fue evaluar nutricionalmente los componentes forrajeros de un SSPi basado en Leucaena leucocephala asociada a pasturas mejoradas, así como su producción de biomasa. La producción de forraje se determinó en varios momentos del año y la calidad nutricional se evaluó mediante el esquema Cornell. La proporción de proteína soluble (fracción A fue similar entre las gramíneas yL. leucocephala, y representó como mínimo el 34 % de la proteína total. La proporción de proteína B2 (degradación intermedia de la leguminosa fue más alta que la de las gramíneas (53,7 vs. 30,2 %, respectivamente. La proteína B3 (degradación lenta de la dieta fue de alrededor de 22 % de la proteína total, y más del 71 % de esta se puede considerar como degradable en el rumen. L. leucocephala presentó una concentración más alta de carbohidratos solubles (16,7 % y menor cantidad de la fracción B2 (14,94 % que las gramíneas. En lo referente a disponibilidad de biomasa, se alcanzó una producción de 19,26 t de MS ha año-1. Se concluye que en los SSPi se produce una alta cantidad de forraje de calidad durante el año, y que esta oferta es suficiente para cubrir los requerimientos de los rumiantes.

  8. Use of exotic species in afforestation and facilitation for the establishment of biological invasion

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    Juliano Ricardo Fabricante

    2017-02-01

    Full Text Available This study aimed to inventory the species used in landscaping the Campus of Agricultural Sciences of the Federal University of Paraíba, Areia, PB, Brazil and to rank them according to their origin and their invasive potential. Through walks throughout the study area (active search, we cataloged all the species used in local afforestation and classified them as native or exotic. Exotic plants were also classified as to their invasive potential. Altogether, we identified 76 species belonging to 67 genera and 25 families. Of these, only 26 species were native. The results of this study are worrisome because of the large number of exotic species used for planting at the study site (50 species, including known aggressive species: Artocarpus heterophyllus Lam., Azadirachta indica A. Juss. and Leucaena leucocephala (Lam. de Wit.

  9. Prospeção de inibidores de serinoproteinases em folhas de leguminosas arbóreas da floresta Amazônica Prospecting serine proteinase inhibitors in leaves from leguminous trees of the Amazon forest

    Directory of Open Access Journals (Sweden)

    Larissa Ramos Chevreuil

    2011-03-01

    Full Text Available Os inibidores de proteinases são proteínas extensivamente investigadas nos tecidos de estocagem, mas pouco prospectadas em outros tecidos vegetais. O objetivo deste estudo foi detectar a presença de inibidores de serinoproteinases em extratos foliares de quinze espécies de leguminosas arbóreas da Amazônia. As espécies estudadas foram: Caesalpinia echinata, C. ferrea, Cedrelinga cateniformis, Copaifera multijuga, Dinizia excelsa, Enterolobium contortisiliquum, E. maximum, E. schomburgkii, Leucaena leucocephala, Ormosia paraensis, Parkia multijuga, P. pendula, P. platycephala, Swartzia corrugata e S. polyphylla. Folhas foram coletadas, secas a 30ºC durante 48 h, trituradas e submetidas à extração com NaCl (0,15 M, 10% p/v resultando no extrato total. Ensaios foram executados para determinar a concentração de proteínas e detectar a atividade inibitória contra a tripsina e quimotripsina bovina. Os teores de proteínas bruta e solúvel nos extratos foliares variaram de 7,9 a 31,2% e 1,3 a 14,8%, respectivamente. A atividade inibitória sobre a tripsina e quimotripsina foi observada em todos os extratos foliares. Contudo, nos extratos de E. maximum, L. leucocephala, P. pendula, S. corrugata e S. polyphylla a inibição foi maior sobre a tripsina, enquanto o extrato de P. multijuga foi mais efetivo contra a quimotripsina. Nós concluímos que nos extratos foliares de leguminosas arbóreas têm inibidores de serinoproteinases e exibem potencial aplicações biotecnológicas.The proteinase inhibitors are proteins extensively investigated in tissue storage, but few prospected in other plant tissues. The aim of this study was to detect the presence of serine proteinase inhibitors in leaf extracts from fifteen species of leguminous trees of the Amazon forest. The species studied were Caesalpinia echinata, C. ferrea, Cedrelinga cateniformis, Copaifera multijuga, Dinizia excelsa, Enterolobium contortisiliquum, E. maximum, E. schomburgkii

  10. Evaluación del comportamiento productivo de búfalos de río en sistema arborizado y en monocultivo de gramíneas Evaluation of the productive performance of river buffaloes in system with trees and grass monocrop

    Directory of Open Access Journals (Sweden)

    L Simón

    2008-06-01

    Full Text Available Se investigó el efecto de la arborización en la crianza de los búfalos de río en dos unidades o fincas con 30 búfalas lecheras cada una y sus crías, y se comparó la tecnología del silvopastoreo racional con Leucaena leucocephala y un monocultivo de gramíneas. Se realizó un diagnóstico inicial para conocer las característi­cas propias de cada unidad y la composición florística de las áreas; mensualmente se determinó la disponibilidad de materia seca de los pastos para regular la carga animal en el pastizal y durante cuatro años consecutivos se midieron los indicadores productivos y reproductivos, así como los ingresos económicos. Los resultados en el sistema arborizado fueron superiores en 0,72 kg de leche por búfala por día; 279,8 kg/lactancia; 1,49 kg/ha/ día y 42 días más de lactancia; no obstante, lo más significativo resultó la producción de leche diaria por hectárea en el sistema arborizado, que triplicó la del monocultivo de gramíneas (2,24 vs 0,75 kg, como producto de una mayor disponibilidad de materia seca y nutrimentos. Ello permitió incrementar la carga animal, lo que se manifestó positivamente en los ingresos por la venta de la leche. Todos los indicadores analizados favorecieron al sistema de leucaena con la tecnología del silvopastoreo racional.The effect of trees on the rearing of river buffaloes was studied in two units or farms with 30 dairy cows each and their calves, and the technology of rational silvopastoral system with Leucaena leucocephala was compared to a grass monocrop. An initial diagnosis was carried out to learn the characteristics of each unit and the floristic composition of the areas. The dry matter availability of the pastures was determined monthly in order to regulate the stocking rate in the pastureland and during four consecutive years the productive and reproductive indicators, as well as the economic incomes, were measured. The results in the tree system were higher in 0

  11. Su excelencia: la medicina basada en evidencias

    OpenAIRE

    Boucourt Rivera, Larissa

    2003-01-01

    La última etapa del siglo XX produjo nuevos retos y tendencias en la práctica de la medicina; la llamada medicina moderna se robustece con un nuevo modelo de práctica clínica: la medicina basada en evidencias. Se establece el origen, filosofía, evolución y lineamientos de este nuevo enfoque y se ofrece una panorámica sobre sus perspectivas de desarrollo en la sociedad actual. Se tratan los retos que plantea al profesional de la información como gestor de la información, del aprendizaje y del ...

  12. Herbaceous energy crops in humid lower South USA

    Energy Technology Data Exchange (ETDEWEB)

    Prine, G.M.; Woodard, K.R. [Univ. of Florida, Gainesville, FL (United States)

    1993-12-31

    The humid lower South has the long warm growing season and high rainfall conditions needed for producing high-yielding perennial herbaceous grasses and shrubs. Many potential biomass plants were evaluated during a ten-year period. Perennial tall grasses such as elephantgrass (Pennisetum purpureum), sugarcane and energycane (Saccharum spp.) and the leguminous shrub Leucaena leucocephala were the highest in biomass production. These perennial crops often have top growth killed by winter freezes and regenerate from underground parts. The tall grasses have high yields because of linear crop growth rates of 18 to 27 g m{sup 2} d{sup {minus}1} for long periods (140 to 196 d) each season. Tall grasses must be planted vegetatively, which is more costly than seed propagation, however, once established, they may persist for many seasons. Oven dry biomass yields have varied from 20 to 45 Mg ha{sup {minus}1} yr{sup {minus}1} in colder subtropical to mild temperate locations to over 60 Mg ha{sup {minus}1} yr{sup {minus}1} in the lower portion of the Florida peninsular. Highest biomass yields have been produced when irrigated with sewage effluent or when grown on phosphatic clay and muck soils in south Florida. The energy content of 1 Mg of oven dry tall grass and leucaena is equivalent to that of about 112 and 123 gallons of number 2 diesel fuel, respectively.

  13. Biomass and carbon stock potential of Gliricidia Sepium as an alternative energy at Timor Tengah Utara Regency, East Nusa Tenggara Province, Indonesia

    Science.gov (United States)

    Prima, F. H.; Hariyadi; Hartono, A.

    2018-03-01

    The utilization of biomass from plants is one efforts for the fulfillment an availability of alternative energy in indonesia. Gliricidia sepium is a tolerant species that can grow in dry land. However its utilization as renewable energy source is non-optimized. This study aims to analyze the potential carbon stocks and biomass from Gliricidia sepium as a raw material for alternative energy in East Nusa Tenggara. This study was conducted in November 2015 and located in Humusu Sainiup, Timor Tengah Utara Regency, East Nusa Tenggara Province. The method used in collecting data was applied in three different land-use, namely monoculture Gliricidia sepium, polyculture between Gliricidia sepium and Leucaena leucocephala, and polyculture between Gliricidia sepium and Zea mays. We used the allometric equation from Ketterings namely B = 0.11ρD2+0,62 and C = 0.5 x B. The results showed that the different land-use will give different value of carbon stocks which is in this study the biggest value of carbon stocks was found in monoculture of Gliricidia sp (35.35 tC ha-1) compared with Gliricidia sp + Leucaena sp (18.83 tC ha-1), and Gliricidia sp + Zea mays (13.79 tC ha-1). The value of biomass and carbon stocks was influenced by wood density, trees density, and diameter at breast height (dbh).

  14. Revegetating Bagacay Mining Site: A review of potential tropical species for phytoremediation of non-essential heavy metals

    Directory of Open Access Journals (Sweden)

    John Rhey Ymas Dayang

    2017-04-01

    Full Text Available Post-mining activities in Samar left serious environmental issues. Albeit it is used to provide prosperity to its constituents, mining in the area brought with it negative impacts. Bagacay Mine, an abandoned mining area in the province was left with enourmous amount of heavy metals. This include As (6-693 ppm, Cu (9-5,279, Pb (22-354 ppm, Hg (1-5 ppm, Zn (<1-7,138 ppm and Fe (5,900-373,500 ppm. The area was then reforested with Swietenia macrophylla, Leucaena leucocephala, Acacia mangium, Bambusa blumeana and Thysanolaena maxima but only 1 percent survived. This paper touches the nature and effects of the non-essential heavy metals and metalloids present in the area as well as the mechanism of phytoextraction. Additionally, tropical metallophytes which can be used for phytoremediation activities in the future were introduced and reviewed.

  15. La gestión de la seguridad basada en los comportamientos: ¿un proceso que funciona?

    Directory of Open Access Journals (Sweden)

    Ciro Martínez Oropesa

    Full Text Available Introducción: El proceso de gestión de la seguridad basada en los comportamientos (PGSBC, se basa en el desarrollo de observaciones a las personas en el cumplimiento de las tareas y retroalimentación de información y reforzamiento positivo en tiempo real, con el propósito de eliminar los comportamientos a riesgos observados, así como, en algunos de los casos más avanzados, modificar los factores ambientales y organizativos que los originan. Esta reflexión se desarrolló con el objetivo de brindar un marco referencial resumido sobre la gestión de la seguridad basada en los comportamientos y aportar datos y fundamentos que permiten resaltar los beneficios e impactos para las empresas. Se realizaron revisiones de una importante información publicada sobre resultados de este proceso. De esta reflexión se deducen y resumen cambios e impactos positivos en la gestión de la seguridad en muchas empresas en las últimas décadas, basada en indicadores proactivos y reactivos de la Seguridad Industrial.

  16. Influência da remoção de cotilédones no desenvolvimento de ramificações nas axilas cotiledonares de plântulas de leguminosas Effect of cotyledon removal on cotyledonal axillary shooting in seedlings of leguminosae

    Directory of Open Access Journals (Sweden)

    Odaci Fernandes de Oliveira

    1999-12-01

    Full Text Available Experimentos inteiramente casualizados foram conduzidos em condições de viveiro com o objetivo de verificar a importância da permanência de cotilédones no desenvolvimento de ramificações nas axilas cotiledonares de plântulas de Phaseolus vulgaris L., Vigna unguiculata (L. Walp., Leucaena leucocephala (Lam. De Wit, Prosopis juliflora (Sw., Tamarindus indica L. e Delonix regia L. Os tratamentos foram: remoção de ambos os cotilédones nos primeiro, segundo e terceiro dias da emergência, remoção de um só cotilédone no primeiro dia da emergência e não remoção de cotilédones. A recuperação do desenvolvimento em plântulas de P. vulgaris, avaliada através da ocorrência de ramificações, independe do número de cotilédones removidos no período de um a três dias da emergência, mas é menos eficiente que em V. unguiculata. A remoção de ambos os cotilédones em plântulas de V. unguiculata, no dia da emergência, afetou a recuperação do desenvolvimento dessas plântulas em comparação com os outros tratamentos. Em plântulas de L leucocephala, P. juliflora, T. indica e D. regia, a remoção de ambos os cotilédones, no período de um a três dias da emergência, sugere o aumento de mortalidade nessas plântulas. A remoção de um único cotilédone não afetou significativamente o percentual de sobrevivência das plântulas nem limitou o surgimento de brotações à axila cotiledonar correspondente ao cotilédone removido.Completely randomized experiments under greenhouse conditions were carried to study the role of cotyledons on the cotyledonal axillary shooting of Phaseolus vulgaris L., Vigna unguiculata (L. Walp., Leucaena leucocephala (Lam. De Wit, Prosopis juliflora (Sw., Tamarindus indica L. and Delonix regia L. The seedlings underwent the following treatments: removal of both cotyledons on the first to the third day after emergence, removal of only one cotyledon on the first day of emergence, and no cotyledon

  17. Selection and production of bacteria which detoxify mimosine: Leucaena leaves may be used as ruminant feed

    Energy Technology Data Exchange (ETDEWEB)

    Boehnel, H. [Institute of Tropical Animal Health, Georg-August-University Goettingen (Germany)], E-mail: hboehne@gwdg.de; Aung, A [Institute of Tropical Animal Health, Georg-August-University Goettingen (Germany); University of Veterinary Sciences, Yezin (Myanmar)

    2009-07-01

    Mimosaceae are shrubs or trees, which grow abundantly in tropical regions. Their leaves contain high value protein which cannot be used as feed due to the toxic substance mimosine and its metabolites in the digestive tract These alkaloids cause diseases in ruminants, mainly loss of hair/wool, and may lead to death in higher concentration. This is the reason why the nutritive value cannot be exploited reasonably in animal production. Experience has shown that there are some geographical regions where animals do not suffer by mimosine. It was found that they harbour ruminal bacteria, which degrade mimosine to non-toxic metabolites. In cooperation with other microbes in the digestive tract, the full dietetic value of Leucaena may be exploited. To date several bacteria were isolated and may be used as feed additive, e.g., S. jonesii. However, their production and storage is expensive and complicated. A practical method is to orally inoculate animals and use their rumen fluid directly as feed additive. This rumen culture or cultured anaerobic bacteria in the laboratory may suffer during transport and storage; hence, they need a cold chain until the target animal. Our institute has an outstanding experience to produce bacterial veterinary vaccines, probiotics, and biological fertilizers in tropical countries. Continuous culture in a bioreactor is the base for the success. It was the idea to use this technology for selection and production of mimosine degrading bacteria. The presentation will give a short theoretical background of - bacterial fermenter production - continuous culture - isolation of specific bacteria under selective environmental conditions - mass production in a bioreactor to be used in tropical areas - purification and concentration of the bacterial crop by rinsing and hollow fibre cross flow ultra filtration - stabilisation of the product in alginate beads - microbiota in the digestive tract. The practical work started with ruminal content of German

  18. Performance of Dairy Goats Fed Rhodes Grass Hay and Supplemented with Leucaena or Gliricidia-Based Concentrates

    International Nuclear Information System (INIS)

    Ondiek, J.O.; Tuitoek, J.K.; Abdulrazak, S.A.

    1999-01-01

    An experiment was conducted to evaluate the performance of dairy goats supplemented with fodder based diets. Six lactating does of Saanen, Toggenburg and Saanen X Toggenburg breed types weighing 46 + or - 7.1 at late stage of lactation were allocated to three dietary treatments in a double 3*3 Latin square design to examine the value of leucaena and gliricidia forages as nitrogen sources in supplementing Rhodes grass hay. Three supplements: Leucaena-based (L), gliricidia-based (G) or commercial concentrate (C) were used. Voluntary feed intake, milk yield, milk composition and live weight changes were measured. Total dry matter intake (DMI) was significantly higher in group G than C (1385 vs 1331 g day -1 ). Hay DMI was higher in G (835 g d -1 than L or C (789, 782 g day -1 , respectively). Diets had no effect on milk yield, crude protein or butterfat content. Total solid was higher in L than C while that of G was intermediate (15.7, 14.7, 13.7%). Weight changes were least affected although resulted in positive gain (11 g day -1 ) while the others lost (-13,-19 g day -, for L and C respectively). In the digestibility trial 6 female goats weighing 22.3 kg (sd 1.1), were allocated to the three treatments in a completely randomised block design where each goat received a different supplement in each of two periods. Thee were no differences in nutrient digestibility except for DM, which was in C compared to the other treatments (615, 622, 720 g-kg for L, G and C, respectively). It si concluded that fodder based supplement compared well with the commercial concentrate in supporting milk yield and body weight gain of dairy goats. Therefore, locally available tree fodders can be incorporated in supplement diets and utilized without any detrimental effects to substitute the expensive concentrates to improve the performance of dairy goats

  19. Alley Farming in Thailand

    Directory of Open Access Journals (Sweden)

    Teerapol Silakul

    2010-08-01

    Full Text Available Poverty alleviation and environmental preservation are very important issues to many governments. Alley farming is beneficial to the environment because it conserves soil and sustains yields over time. Specifically, alley farming reduces soil erosion, which is a major problem in Thailand. Alley farming was conducted on a farmer’s field at Khaokwan Thong, a village in Uthaithani Province, Northern Thailand. We did a two-by-two factorial with and without alley farming, and with and without fertilizer. From this study, we observed that the two species used, Leucaena leucocephala and Acacia auriculiformis, grow well in Thailand, and that alley farming is suitable for Thailand. Few Thai farmers have heard about alley farming. However, it is nevertheless useful to know that there is potential for alley farming in Thailand using the two species. These plants, based upon the diameter and height measurements provided, grew well.

  20. Inquérito epidemiológico sobre plantas tóxicas das mesoregiões Central e Oeste do Rio Grande do Norte

    Directory of Open Access Journals (Sweden)

    Severino Antonio Geraldo Neto

    2013-07-01

    Full Text Available Foi realizado um estudo para determinar as plantas tóxicas incriminadas como de interesse zootécnico em 35 municípios das mesorregiões Central e Oeste do estado do Rio Grande do Norte (RN. Foram entrevistados 180 produtores, 20 médicos veterinários, 12 técnicos agrícolas e 5 agrônomos. Os dados obtidos nas entrevistas foram compilados e analisados com auxílio do programa Epi Info versão 6.04. As plantas tóxicas relatadas pelos entrevistados como causadoras de diversos surtos foram Ipomoea asarifolia, Aspidosperma pyrifolium, Indigofera suffruticosa, Manihot carthaginensis subsp. glaziovii, Amorimia septentrionalis, Tephrosia cinerea, Anadenanthera colubrina var. cebil, Marsdenia megalantha, Anacardium occidentale, Cnidoscolus quercifolius, Crotalaria retusa, Froelichia humboldtiana, Ipomoea carnea, Leucaena leucocephala, Manihot esculenta, Mimosa tenuiflora, Nerium oleander, Prosopis juliflora, Ricinus communis, Sorghum bicolor, Sorghum halepense e Urochloa (Brachiaria decumbens.

  1. Influence of ambient sulphur dioxide on chlorophyll

    International Nuclear Information System (INIS)

    Shahare, C.B.; Varshney, C.K.

    1995-01-01

    For the evaluation of the injury due to SO 2 from Indraprashtha (IP) Thermal Power Plant, eight species of trees were selected. Experiment was divided in two sections. Section one include transplanted tree saplings of Bauhinia variegata, Delonix regia, Flcus benghalensis, Putranjiwa roxburghii, Morus indica, Polyalthia longifolia, Leucaena leucocephala and Tabernaemontana coronaria. Here one set of plants was transplanted to polluted site of IP and other set was maintained at non polluted site of Jawaharlal Nehru University (Ecological Nursery). Second section of the study have naturally growing trees of the same species in the vicinity of the transplanted plants. Findings of the present study show that tree species were not safe at polluted site. Maximum chlorophyll reduction occurred in Bauhinia variegata, that is 32.05% (transplanted saplings). In naturally growing trees up to 35.70% reduction was seen in B. variegata. (author). 11 refs., 2 tabs

  2. EKSPLORASI DAN PRODUKTIFITAS PADANG PENGGEMBALAAN DI KECAMATAN PAMONA TIMUR KABUPATEN POSO SULAWESI TENGAH

    Directory of Open Access Journals (Sweden)

    P.D.M.H. Karti

    2015-06-01

    Full Text Available Pasture in District of East Pamona, Poso Regency has potential as forage for livestock.. This study was conducted in two villages (Didiri and Kelei to explore of plant species as feed and productivity calculation such as botanical composition and carrying capacities. Type of grasses that grow are Sporobolus sp, Paspalum sp, Paspalum cartilagineum, Axonopus compresus, Euleusine indica. Type of legumes that grow are Stylosanthes guianensis, Desmodium sp, Centrocema pubescens, Callyandra callothyrsus, Leucaena leucocephala. Types of weeds have started to grow in several locations within the region, such as Melastoma, Mimosa pudica, Imperata cylindrica, Cromolena odorata, Cyperacea, and Lamtana camara. Botanical composition (% in Kelei for grass, legumes, weeds (84.76: 6.75: 8:49 and Didiri for grass, legumes, weeds (95.34: 0:51: 4.15. Carrying Capacities in Kelei and Didiri was 0.96 ± 0:23 and 1:12 ± 0:29 ST / ha.

  3. ECONOMÍA COMPUTACIONAL BASADA EN AGENTES

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    FABIÁN ANDRÉS GIRALDO GIRALDO

    2012-12-01

    Full Text Available El artículo tiene como objetivo mostrarvarios trabajos de investigación sobre un enfoque desimulación denominado Economía computacional basadaen agentes, el cual rechaza las asunciones delos enfoques de estudio tradicionales que indican quela economía es un sistema cerrado que eventualmentelogra un estado de equilibrio, en el que deben realizarsesupuestos de racionalidad perfecta e inversioneshomogéneas para que los modelos sean tratadosanalíticamente. En su lugar, ve a la economía comoun sistema complejo, adaptativo y dinámico. Estenuevo enfoque permite usar la simulación basada enagentes para comprender que varios agentes económicos(firmas, grupos económicos con sus propiasreglas y objetivos, son capaces de interactuar entresí y con su entorno para obtener comportamientosemergentes que no son explicables directamente delas propiedades de los agentes individuales.

  4. Feeding of tropical trees and shrub foliages as a strategy to reduce ruminal methanogenesis: studies conducted in Cuba.

    Science.gov (United States)

    Delgado, Denia Caridad; Galindo, Juana; González, Rogelio; González, Niurca; Scull, Idania; Dihigo, Luís; Cairo, Juan; Aldama, Ana Irma; Moreira, Onidia

    2012-06-01

    The aim of this paper was to present the main results obtained in Cuba on the effects of feeding tropical trees and shrubs on rumen methanogenesis in animals fed with low quality fibrous diets. More than 20 tree and shrub foliages were screened for phytochemicals and analyzed for chemical constituents. From these samples, seven promising plants (Samanea saman, Albizia lebbeck, Tithonia diversifolia, Leucaena leucocephala, Trichantera gigantea, Sapindus saponaria, and Morus alba) were evaluated for methane reduction using an in vitro rumen fermentation system. Results indicated that the inclusion levels of 25% of Sapindo, Morus, or Trichantera foliages in the foliages/grass mixtures (grass being Pennisetum purpureum) reduced (P lebbeck, or T. diversifolia accession 23 foliages when mixed at the rate of 30% in Cynodon nlemfuensis grass produced lower methane compared to the grass alone. Inclusion levels of 15% and 25% of a ruminal activator supplement containing 29% of L. leucocehala foliage meal reduced methane by 37% and 42% when compared to the treatment without supplementation. In vivo experiment with sheep showed that inclusion of 27% of L. leucocephala in the diet increased the DM intake but did not show significant difference in methane production compared to control diet without this foliage. The results of these experiments suggest that the feeding of tropical tree and shrub foliages could be an attractive strategy for reduction of ruminal methanogenesis from animals fed with low-quality forage diets and for improving their productivity.

  5. Evaluación de las propiedades de materiales compuestos fabricados a partir de fibras semiquímicas de Leucaena collinsii y polipropileno

    OpenAIRE

    Granda Garcia, Luis Angel

    2016-01-01

    La presente tesis estudia el efecto que produce reforzar una fibra semiquímica de Leucaena collinsii en las propiedades mecánicas, térmicas y de sorción de agua de materiales compuestos de polipropileno. Se obtienen probetas de materiales compuestos con distinto contenido de refuerzo y se estabilizan en una cámara climática durante 48 horas antes de ser ensayadas a tracción, flexión e impacto, y se analiza la morfologia de la fractura mediante SEM. Posteriormente se estudian sus propiedad...

  6. Enantioselective synthesis of possible diastereomers of heptadeca-1-ene-4,6-diyne-3,8,9,10-tetrol; putative structure of a conjugated diyne natural product isolated from Hydrocotyle leucocephala.

    Science.gov (United States)

    Prasad, Kavirayani R; Swain, Bandita

    2011-04-01

    Enantioselective synthesis of possible diastereomers of heptadeca-1-ene-4,6-diyne-3,8,9,10-tetrol, a structure proposed for the natural product isolated from Hydrocotyle leucocephala is accomplished. The reported spectral data of the natural product did not match those of any of the isomers that were synthesized and established that the structure proposed for the natural product is not correct and requires revision.

  7. Performance of biomass availability and chemical composition of 23 Leucaena spp. accessions; Comportamiento de la disponibilidad de biomasa y la composición química en 23 accesiones de Leucaena spp.

    Energy Technology Data Exchange (ETDEWEB)

    Wencomo, Hilda B., E-mail: hilda.wencomo@indio.atenas.inf.cu [Estación Experimental de Pastos y Forrajes ' Indio Hatuey' , Central España Republicana, CP 44280, Matanzas (Cuba); Ortiz, R. [Instituto Nacional de Ciencias Agrícolas, Mayabeque (Cuba)

    2012-07-01

    A study was conducted with 23 Leucaena spp. accessions in an area which had been planted six years before. The objective was to determine, in the established plants, total biomass, edible biomass, ligneous biomass, stem diameter and number of branches in each accession, and its bromatological composition under simulated grazing conditions. The research was conducted at the EEPF 'Indio Hatuey' during two years, on a hydrated ferruginous nodular humic lixiviated Ferralitic Red soil. Simple 3 m x 6 m plots were used. In the edible biomass and its components (leaves and fresh stems), there were significant differences (P<0,05) between the seasons of the two years. It could be observed that production was higher in the rainy season than in the dry season, although there were no differences among the mean biomass production of the accessions; in the case of total biomass no significant differences were found between seasons. To continue the studies is recommended, to determine, in the long term, the effect of the evaluated indicators on the availability and persistence of the tree. (author)

  8. Preferencia de vacunos por el follaje de doce especies con potencial para sistemas agrosilvopastoriles en el Estado Trujillo, Venezuela Preference of cattle for the foliage of twelve species with potential for agrosilvopastoral systems in the Trujillo State, Venezuela

    Directory of Open Access Journals (Sweden)

    D.E García

    2008-09-01

    Full Text Available Con el objetivo de conocer la preferencia de bovinos jóvenes por doce especies forrajeras en el Estado Trujillo, Venezuela (Chlorophora tinctoria, Morus alba, Pithecellobium pedicellare, Gliricidia sepium, Guazuma ulmifolia, Cordia alba, Trichantera gigantea, Tithonia diversifolia, Leucaena leucocephala, Moringa oleifera, Azadirachta indica y Samanea saman se efectuó una prueba de cafetería a través de mediciones del consumo de follaje, mediante un diseño cuadrado latino con período de evaluación de 12 días. A los forrajes se les determinó la composición fitoquímica (PB, EB, FDN, fenoles, taninos condensados, taninos que precipitan proteínas y esteroles totales y la degradabilidad ruminal in situ (DMS y DMO. Las especies más preferidas fueron: P. pedicellare (327,98 g MS, L. leucocephala (325,63 g MS, M. alba (293,37 g MS, G. ulmifolia (292,48 g MS, C. tinctoria (277,18 g MS y C. alba (274,49 g MS. Los follajes de G. sepium (108,05 g MS, T. diversifolia (106,09 g MS, M. oleifera (76,28 g MS, A. indica (76,19 g MS y S. saman (58,72 g MS fueron medianamente consumidos. Sin embargo, la biomasa de T. gigantea (1,39 g MS fue prácticamente rechazada. Durante el período experimental se observaron diferentes tendencias en el consumo de cada espe­cie. No obstante, no se observó una relación significativa entre el consumo y la composición química, la concentración de metabolitos secundarios y la degradabilidad ruminal. Se concluye que es importante realizar ensayos de preferencia con animales para la selección de especies con potencial para sistemas silvopastoriles.With the objective of knowing the preference of young cattle for twelve forage species of the Trujillo State, Venezuela (Chlorophora tinctoria, Morus alba, Pithecellobium pedicellare, Gliricidia sepium, Guazuma ulmifolia, Cordia alba, Trichantera gigantea, Tithonia diversifolia, Leucaena leucocephala, Moringa oleifera, Azadirachta indica and Samanea saman a cafeteria test

  9. Caracterização da fauna edáfica em sistemas de manejo para produção de forragens no Estado do Piauí Characterization of edaphic fauna in management systems for forage production in the State of Piauí

    Directory of Open Access Journals (Sweden)

    Luís Alfredo Pinheiro Leal Nunes

    2012-03-01

    Full Text Available O objetivo desse trabalho foi avaliar a distribuição da fauna em função da umidade do solo em diferentes sistemas de manejo para a produção de forragens com capim-Tifton 85 (Cynodon dactylon Pers. x C. niemfuensis Vanderys, capim-Tanzânia (Panicum maximum Jacq. cv. Tanzânia, capim-Andropogon (Andropogon gayanus Kunth, Leucena (Leucaena leucocephala (Lam. R. de Wit. tendo como controle uma Mata dos Cocais. A coleta da fauna foi feita utilizando-se armadilhas do tipo Pitfall em duas épocas do ano: setembro de 2007 e março de 2008, período seco e chuvoso, respectivamente. Os sistemas com capim-Tifton, capim-Tanzânia e Leucena mostraram maior número de indivíduos nos dois períodos avaliados. A queimada ocorrida no capim-Andropogon antes da primeira coleta resultou em uma redução na abundância e diversidade da fauna edáfica. Os maiores valores em riqueza, diversidade e uniformidade de fauna foram obtidos na amostragem realizada no período úmido. A mata mostrou maior diversidade e equitabilidade nos dois períodos avaliados. Em situação de estresse hídrico alguns grupos como Formicidae e Collembola predominaram nos sistemas de manejo diminuindo a uniformidade, enquanto no período úmido vários grupos mostraram boa representatividade o que favoreceu a uniformidade. A análise multivariada de componentes principais evidenciou que os sistemas com mata, capim-Tifton e capim-Tanzania e Leucena mostraram associação com vários grupos da fauna edáfica nos dois períodos avaliados enquanto que o sistema com capim-Andropogon, que sofreu queimada, apresentou afinidade apenas com o grupo Heteroptera, no período seco.The objective of this study was to evaluate the distribution of fauna as a function of soil moisture in different fodder-production management systems of Tifton 85 grass (Cynodon dactylon Pers. x C. niemfuensis Vanderys, Tanzania grass (Panicum maximum Jacq. cv. Tanzânia, Andropogon Grass (Andropogon gayanus Kunth and

  10. Efecto del sistema silvopatoril en el comportamiento productivo de vacas Holstein Effect of the silvopastoral system on the productive performance of Holstein cows

    Directory of Open Access Journals (Sweden)

    L Lamela

    2009-06-01

    Full Text Available Con el objetivo de evaluar el comportamiento productivo de vacas Holstein en sistemas asociados de Leucaena leucocephala y Cynodon nlemfuensis, sin la aplicación de fertilizante químico, se realizó el presente trabajo en dos vaquerías: las unidades 98 y 100 de la Empresa Genética de Matanzas, Cuba, las cuales tenían un área de pastos de 35,5 ha y 3 ha para la producción de forraje de caña de azúcar. Se determinó la producción de leche por vaca en ordeño y la producción por vaca total, así como la influencia del bimestre de producción, la época del año y el año en el comportamiento productivo. La leucaena tuvo valores de PB superiores al 20% y la gramínea entre 7,4-9,5%; la disponibilidad de MS fue de 3,4 y 2,5 t/ha/rotación para el período lluvioso y el poco lluvioso, respectivamente. Se encontraron diferencias significativas dentro de cada vaquería para el efecto bimestre de producción. A su vez, el 86 y 65% de las vacas tuvieron una condición corporal (CC entre 3,0 y 3,5 para el período lluvioso y el poco lluvioso, respectivamente. La producción de leche promedio de las vacas, para la CC de 2,5; 3,0; 3,5 y 4,0 fue de 6,5; 8,0; 7,7 y 6,0 kg/vaca/día, respectivamente. Se concluye que el sistema presentó una aceptable disponibilidad de MS (3 t/ha/rotación y los animales mantuvieron una condición corporal favorable para la producción de leche, con valores de 6,8-8,8 kg/vaca/día.With the objective of evaluating the productive performance of Holstein cows in associated systems of Leucaena leucocephala and Cynodon nlemfuensis, without applying chemical fertilizers, this work was carried out in two dairy units: 98 and 100 of the Livestock Production Genetic Enterprise of Matanzas, Cuba, which had an area for pastures of 35,5 ha and 3 ha for producing sugarcane forage. The milk production per milking cow and total production per cow were determined, as well as the influence of the two-month period of production, season

  11. Rehabilitation with pasture after open-cut coal mining at three sites in the Bowen Coal Basin of Queensland

    Energy Technology Data Exchange (ETDEWEB)

    Coaldrake, J E

    1978-03-01

    Open-cut coal mining in the Bowen Coal Basin leaves piled heaps of overburden, chiefly of a clayey nature, that have high pH, high salinity, and low contents of phosphorus and nitrogen. It is likely that pastures of introduced sub- tropical species can be used as a first stage in rehabilitating these areas, and possibly to convert them into permanent grazing lands. In field experiments the grasses Cenchrus ciliaris cv. Biloela (Buffel grass), Chloris gayana cv. Pioneer (Rhodes grass) and Panicum maximum var. trichoglume cv. Petrie (green panic) all showed satisfactory establishment and growth at two sites out of three tested. There was a clear response to superphosphate, with 400 kg/ha proving better over a two-year period than 100 kg/ha. Responses to nitrogen (as ammonium sulphate and as ammonium nitrate) were variable, and there was no response to gypsum and manganese at the one site tested for them. Of three tropical legumes subjected to limited testing only leucaena leucocephala gave encouraging results.

  12. Passive restoration following ungulate removal in a highly disturbed tropical wet forest devoid of native seed dispersers

    Science.gov (United States)

    Nafus, Melia; Savidge, Julie A.; Yackel Adams, Amy A.; Christy, Michelle T.; Reed, Robert

    2018-01-01

    Overabundant ungulate populations can alter forests. Concurrently, global declines of seed dispersers may threaten native forest structure and function. On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for 7 years following ungulate exclusion from a 5-ha area and adjacent plots with ungulates still present. We observed succession from open scrub to forest and understory cover by non-native plants declined. Two trees, native Hibiscus tiliaceus and non-native Leucaena leucocephala, accounted for most forest regeneration, with the latter dominant. Neither species is dependent on animal dispersers nor was there strong evidence that plants dependent on dispersers migrated into the 5-ha study area. Passive restoration following ungulate removal may facilitate restoration, but did not show promise for fully restoring native forest on Guam. Restoration of native forest plants in bird depopulated areas will likely require active outplanting of native seedlings, control of factors resulting in bird loss, and reintroduction of seed dispersers.

  13. Eficiência simbiótica de estirpes de Cupriavidus necator tolerantes a zinco, cádmio, cobre e chumbo

    Directory of Open Access Journals (Sweden)

    Paulo Ademar Avelar Ferreira

    2012-01-01

    Full Text Available O objetivo deste trabalho foi avaliar a tolerância de estirpes de Cupriavidus necator a zinco, cádmio, cobre e chumbo, além de determinar a eficiência simbiótica das estirpes mais tolerantes em associação a espécies leguminosas com potencial para revegetação. A tolerância foi testada em meio LB, suplementado com 2,5; 5,0; 7,5; 10; 12,5 e 15 mmol L-1 de ZnSO4.7H2O, CdSO4.8H2O, CuSO4.5H2O e PbCl2, respectivamente, em comparação ao controle sem adição de metal. Determinou-se a eficiência simbiótica das quatro estirpes de C. necator mais tolerantes aos metais avaliados (UFLA02-71, UFLA02-73, UFLA01-659 e UFLA01-663, as quais foram inoculadas nas espécies: Leucaena leucocephala, Enterolobium contortisiliquum, Acacia mangium, Mimosa caesalpiniifolia, M. pudica, M. pigra e M. acutistipula. Em vasos com solos, avaliaram-se L. leucocephala, M. pudica e M. caesalpiniifolia e as estirpes UFLA01-659 e UFLA02-71, selecionadas na avaliação de eficiência simbiótica. A estirpe UFLA02-71 proporcionou incrementos de matéria seca da parte aérea de 870% em M. caesalpiniifolia, enquanto que UFLA01-659 proporcionou 885% em M. pudica e 924% em L. leucocephala. As estirpes UFLA01-659 e UFLA02-71, além da alta tolerância a metais pesados, apresentaram eficiência em fixar nitrogênio, em simbiose com essas leguminosas, em solos com rizóbios nativos capazes de nodulá-las, e devem ser avaliadas quanto ao seu potencial de utilização em programas de recuperação de áreas degradadas.

  14. Content of heavy metals and naturally occurring radioactive material in Leucaena leucocaphala (Lam.) de wit

    International Nuclear Information System (INIS)

    Nurul Sareeza Azidin

    2012-01-01

    This research was done to determine the content of heavy metals in Leucaena leucocaphala (Lam.) de Wit (Petai Belalang) at 5 different areas. Those areas were in the middle of city, former mining area, industrial area, domestic waste disposal area, and on expressway roadside. Heavy metal poisoning can happen if the concentration is too high and will cause severe damage to human health. For instance, it may cause gene mutation, cancer and damage to the human body systems. This plant was selected for the study of heavy metals and radionuclide content in the soil. The reason of selecting this plant is because this plant can live in extreme conditions, and perhaps able to absorb those elements better than other legumes. The aim of this study was to determine the content of toxic heavy metals in leaves, stems and roots of Leucaena leucocaphala including the soil where it is grown. The second objective was determine NORM in the soil where the plant grew and the last objective was to determine the transfer factor of heavy metals by the plant. The content analysis of toxic heavy metals for example Cu, Zn, Cd, Hg and Pb were determined by using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Gamma ray spectrometry on the other hand, was used to determine K-40, Ra-226, U-238 and Th-232 in the soil where the plant was sampled. The activity concentration of Ra-226, K-40, U-238 and Th-232 determined were 7.47 ± 3.03 Bq/ kg - 256.92 ± 164.36 Bq/ kg, 95.55 ± 72.62 Bq/ kg - 435.60 ± 88.32 Bq/ kg, 21.83 ± 8.83 Bq/ kg - 165.28 ± 109.61 Bq/ kg dan 43.41 ± 7.06 Bq/ kg - 91.19 ± 11.13 Bq/ kg respectively. In general, the former mining area recorded the highest heavy metal concentration for Cu (28.20 ± 32.54 mg/ kg), Zn (114.67 ± 75,61 mg/ kg), Cd (0.31 ± 0.11 mg/ kg) and Pb (48.08 ± 33.60 mg/ kg). Whereas the highest concentration of As recorded was on the roadside (261.92 ± 132.64) and Hg (0.44 ± 0.36 mg/kg) in the middle of the city. (author)

  15. Consumo de forrajes tropicales por vacas lecheras, mestizas Siboney, manejadas en condiciones de estabulación

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    Julio J. Reyes

    2015-01-01

    Full Text Available Con el objetivo de estudiar el comportamiento de tres forrajes tropicales y su consumo por animales lecheros, durante tres años, se utilizó un área total de cultivos de 4.25 hectáreas, distribuidas en 1.50 hectáreas para caña de azúcar (Sacharum officinarun, 2 hectáreas del king grass clon CT-169 (Pennisetum purpureum vc Cuba CT-169 y 0.75 hectáreas de leucaena (Leucaena leucocephala; para estimar el consumo, se utilizaron 20 vacas lecheras mestizas de Siboney, mantenidas en régimen de estabulación, con dieta semi-integral. Se realizó un análisis de varianza, según diseño completamente aleatorizado, en arreglo factorial. Los resultados arrojan que las disponibilidades promedio del forraje caña de azúcar fueron mayores (P<0.05 en la época poco lluviosa: 1,916.64 vs. 1,474.73 kg MS ha-1 mes-1; mientras que los forrajes de CT-169 y leucaena fueron superiores sus disponibilidades (P<0.01 en la época lluviosa: 924.76 y 519.01 vs. 649.10 y 314.20 kg MS ha-1 mes-1, respectivamente. La calidad de los forrajes fue menor (P<0.001 en la época poco lluviosa. Los consumos totales de materia seca que realizaron los animales, fue superior (P<0.001 en la época lluviosa (10.56 vs. 9.33 kg MS animal-1 día-1; mientras que los animales de ordeño realizaron un mayor (P<0.001 consumo que los secos (10.82 vs. 9.06 kg MS animal-1 día-1. Los resultados expresan la posibilidad del sistema en estabulación de mantener una carga promedio de 4.70 a 4.9 UGM ha-1, con vacas lecheras de mediano potencial y obtener un consumo adecuado de estos forrajes.

  16. Digestion, growth performance and caecal fermentation in growing rabbits fed diets containing foliage of browse trees

    Directory of Open Access Journals (Sweden)

    S.H. Abu Hafsa

    2016-12-01

    Full Text Available This study aimed to evaluate the effect of feeding dried foliage (leaves and petioles of Acacia saligna, Leucaena leucocephala or Moringa oleifera on the performance, digestibility, N utilisation, caecal fermentation and microbial profiles in New Zealand White (NZW rabbits. One hundred weaned male NZW rabbits weighing 819.2±16.6 g and aged 35±1 d were randomly allocated into 4 groups of 25 rabbits each. Rabbits were fed on pelleted diets containing 70% concentrate mixture and 30% Egyptian berseem (Trifolium alexandrinum hay (Control diet or one of the other 3 experimental diets, where 50% of berseem hay was replaced with A. saligna (AS, L. leucocephala (LL or M. oleifera (MO. Compared to Control diet, decreases in dry matter (DM; P=0.004, organic matter (P=0.028, crude protein (CP; P=0.001, neutral detergent fibre (P=0.033 and acid detergent fibre (P=0.011 digestibility were observed with the AS diet. However, DM and CP digestibility were increased by 3% with the MO diet, and N utilisation was decreased (P<0.05 with AS. Rabbits fed AS and LL diets showed decreased (P=0.001 average daily gain by 39 and 7%, respectively vs. Control. Feed conversion was similar in Control and MO rabbits, whereas rabbits fed AS diet ate up to 45% more feed (P=0.002 than Control rabbits to gain one kg of body weight. Caecal ammonia-N was increased (P=0.002 with LL, while acetic acid was decreased (P=0.001 with AS diet vs. other treatments. Caecal E. coli and Lactobacillus spp. bacteria counts were decreased with MO by about 44 and 51%, respectively, vs. Control. In conclusion, under the study conditions, tree foliage from M. oleifera and L. leucocephala are suitable fibrous ingredients to be included up to 150 g/kg in the diets of growing rabbits, and can safely replace 50% of berseem hay in diets of NZW rabbits without any adverse effect on their growth performance. Foliage from M. oleifera had a better potential as a feed for rabbits than that from L

  17. FORAGE OFFER AND INTAKE AND MILK PRODUCTION IN DUAL PURPOSE CATTLE MANAGED UNDER SILVOPASTORAL SYSTEMS IN TEPALCATEPEC, MICHOACAN

    Directory of Open Access Journals (Sweden)

    Hector Manuel Bacab-Pérez

    2011-11-01

    Full Text Available The study was carried out during the dry season (March to May in three dual-purpose cattle farms located in Tepalcatepec, Michoacan, Mexico, in order to evaluate the forage offer and intake, and milk production in Brown Swiss cows. Two farms had silvopastoral systems with Leucaena leucocephala cv. Cunningham associated with Panicum maximum cv. Tanzania, and one of them also included mango trees (Mangifera indica; the third farm had a traditional system with Cynodon plectostachyus in monoculture. In the traditional system, cows were offered 8 kg animal-1 day-1 of concentrate feed during the milking period, and only 1.5 kg animal-1 day-1 in the silvopastoral systems. Edible forage offer in the silvopastoral farms was 2470 and 2693 kg DM ha-1 grazing-1, and in the traditional system it was 948 kg DM ha-1 grazing-1. Forage intake in the silvopastoral systems was 8.25 and 11.81 kg DM animal-1 day-1, whereas in the traditional system it was 3.63 kg DM animal-1 day-1. Milk production in the silvopastoral system was 9.0 and 9.2 kg animal-1 day-1, while in the traditional system it was 10.4 kg animal-1 day-1. The silvopastoral systems with L. leucocephala cv. Cunningham associated with P. maximum cv. Tanzania produced high edible forage offer and allowed to obtain milk yield similar to that of the traditional system with C. plectostachyus in monoculture, but on a lower concentrate feed intake.

  18. Investigação das atividades antioxidante e antimicrobiana de duas espécies arbóreas ocorrentes no bioma caatinga

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    Fábio Rogério Santos Nunes

    2016-05-01

    Full Text Available O bioma caatinga é um bioma brasileiro predominante e único no Nordeste do Brasil. Esse bioma abriga uma impressionante biodiversidade florística com espécies ricas em moléculas bioativas. O objetivo deste trabalho foi investigar a atividade antioxidante e antimicrobiana de duas espécies vegetais arbóreas ocorrentes na caatinga. Nos ensaios de atividade antioxidante dos extratos etanólicos da casca do caule das espécies Leucaena leucocephala e Cnidoscolus quercifolius foram avaliados o teor de fenólicos totais e atividade antioxidante pelos métodos de captura dos radicais livres DPPH (radical 1,1-diphenil-2-picrilhydrazil e ABTS (radical 2,2’azinobis-(3-ethylbenzthiazoline-6-sulfonic acid. A atividade antimicrobiana desses extratos foi avaliada frente às espécies bacterianas Enterococcus faecales (ATCC 29212, Streptococcus pneumoniae (ATCC 49619 e Staphylococcus aureus (ATCC 25923, através do ensaio de difusão em poço e determinação de Concentração Inibitória Mínima (CIM.   Os teores de fenólicos totais encontrados na espécie L. leucocephala exibiram quantidades relevantes de polifenóis, resultado não observado na espécie C. quercifolius.  Foi observado existir uma correlação direta entre a quantidade de fenólicos totais e a atividade antioxidante das espécies testadas. Nenhuma das espécies apresentou atividade antimicrobiana significativa.

  19. SUPPLEMENTARY FEEDING ON THE NUTRIENT BALANCE OF LACTATING DAIRY COW AT CONTRASTING TEMPERATURE REGIMES: ASSESSMENT USING CORNELL NET CARBOHYDRATE AND PROTEIN SYSTEM (CNCPS MODEL

    Directory of Open Access Journals (Sweden)

    A. Jayanegara

    2014-10-01

    Full Text Available Dairy cows often do not receive adequate nutrient supply during their lactation period. This condition caneven be worse if the environmental temperature is not in comfortable range which may occur especially intropical regions. The present research was aimed to simulate the effect of supplementary feeding on nutrientbalance of lactating dairy cow at contrasting temperature regimes using Cornell Net Carbohydrate andProtein System (CNCPS model. Treatments consisted of feeds (R1: Pennisetum purpureum, R2: P.purpureum + concentrate (60:40, R3: P. purpureum + Gliricidia sepium + Leucaena leucocephala(60:20:20, R4: P. purpureum + concentrate + G. sepium + L. leucocephala (60:20:10:10 and environmentaltemperatures (T1: 20 oC, T2: 30 oC. The dairy cow inputs in CNCPS were Holstein breed, body weight of500 kg, feed intake of 15 kg (dry matter basis per day and produced milk 15 kg/day. Based on the CNCPSmodel, there were negative balances of metabolisable energy (ME and metabolisable protein (MP if alactating dairy cow fed only by P. purpureum. The ME balance was worse at higher temperature, while theMP balance was remain unchanged. Addition of concentrate mixture (R2 fulfilled the ME and MPrequirements as well as other nutrients. Addition of leguminous tree leaves (R3 and R4 improved thenutritional status of the lactating cow model compared to R1, but did not better than R2. It was concludedthat supplementary feeding is necessary for improving the nutrient balance of lactating dairy cow, especiallywhen the cow is maintained under uncomfortable environmental temperature.

  20. Ability of a Generalist Seed Beetle to Colonize an Exotic Host: Effects of Host Plant Origin and Oviposition Host.

    Science.gov (United States)

    Amarillo-Suárez, A; Repizo, A; Robles, J; Diaz, J; Bustamante, S

    2017-08-01

    The colonization of an exotic species by native herbivores is more likely to occur if that herbivore is a generalist. There is little information on the life-history mechanisms used by native generalist insects to colonize exotic hosts and how these mechanisms are affected by host properties. We examined the ability of the generalist seed beetle Stator limbatus Horn to colonize an exotic species. We compared its host preference, acceptability, performance, and egg size when ovipositing and developing on two native (Pithecellobium dulce (Roxb.) Benth and Senegalia riparia (Kunth)) and one exotic legume species (Leucaena leucocephala (Lam.)). We also analyzed the seed chemistry. We found that females recognize the exotic species as an unfavorable host for larval development and that they delayed oviposition and laid fewer and larger eggs on the exotic species than on the native species. Survivorship on the exotic host was 0%. Additionally, seeds of the native species contain five chemical compounds that are absent in the exotic species, and the exotic species contains three sterols, which are absent in the native legumes. Genetically based differences between beetles adapted to different hosts, plastic responses toward new hosts, and chemical differences among seeds are important in host colonization and recognition of the exotic host. In conclusion, the generalist nature of S. limbatus does not influence its ability to colonize L. leucocephala. Explanations for the colonization of exotic hosts by generalist native species and for the success of invasive species must be complemented with studies measuring local adaptation and plasticity.

  1. Evaluación de canales de bovinos machos engordados en sistemas silvopastoriles

    Directory of Open Access Journals (Sweden)

    Jorge Iraola

    2016-01-01

    Full Text Available Se evaluaron 90 canales de tres ciclos productivos de bovinos machos, cebados en un sistema silvo-pastoril con inclusión de Leucaena leucocephala. Se utilizaron 30 animales por cada ciclo productivo: Cebú, Cebú mestizo y Mestizos lecheros Holstein x Cebú , con un peso vivo de sacrificio entre 399 y 420 kg. Se aplicó un modelo lineal mixto a partir de un PROC MIXED del SAS. Se consideraron, como efectos fijos: ciclo productivo, la interacción de la covarianza del peso al sacrificio con el ciclo productivo; y como aleatorios: el efecto del animal anidado dentro de ciclo productivo y el error residual. Se estudiaron los indicadores: peso sacrificio, peso de la canal caliente, peso de la canal fría, carne, hueso y grasa, el rendimiento de todas las partes de la canal. Se realizaron análisis de regresiones lineales relacionadas con el rendimiento cárnico con el programa estadístico INFOSTAT. Se encontraron diferencias (P<0.05 entre ciclos productivos respecto de la canal y las demás partes. El tercer ciclo presentó el mayor porcentaje de hueso en la canal y menor rendimiento cárnico. Todos los ciclos productivos manifestaron un comportamiento lineal favorable en silvopastoreo con leucaena. Se concluye que los ciclos 1 y 2 tuvieron mejor comportamiento en canal con respecto al tercer ciclo con los animales Mestizos lecheros; lo cual está asociado al plano de alimentación y el peso de sacrificio que condicionaron el rendimiento cárnico.

  2. Uso de métodos anticonceptivos asociado a violencia basada en género en mujeres en edad fértil. Centro de Salud Grocio Prado, Ica. 2015

    OpenAIRE

    Trujillo Charaja, Aurea del Carmen

    2017-01-01

    Determina la asociación entre la violencia basada en género con el uso de métodos anticonceptivos en mujeres en edad fértil que acuden al Centro de Salud Grocio Prado en Ica, 2015. Materiales y método: El tipo de estudio fue analítico, prospectivo y transversal. Con un diseño de cohorte. La población estuvo constituida por 683 mujeres. Muestra constituida por 70 mujeres en edad fértil, 35 con violencia basada en género y 35 sin violencia basada en género en las que se evaluó el uso de mét...

  3. Nuevo método de conexión de termistores a microcontroladores basada en la técnica de conversión digital directa

    OpenAIRE

    Custodio Ruiz, Ángel Augusto; Díaz, Alfred

    2006-01-01

    En este trabajo se presenta el diseño e implementación de un circuito electrónico interfaz para termistores basada en la técnica de conversión digital directa a microcontroladores, que no requiere utilizar ni amplificadores ni convertidores analógico a digital. La alternativa para la solución del diseño aquí planteado está basada en el microcontrolador PIC16F84A, implementado mediante un software en lenguaje ensamblador que permitirá estimar el valor del sensor termistor mediante relaciones a...

  4. Assessing the invasive potential of biofuel species proposed for Florida and the United States using the Australian Weed Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, D.R. [The Nature Conservancy, PO Box 118526, University of Florida, Gainesville, FL 32611 (United States); Department of Biology, PO Box 118526, University of Florida, Gainesville, FL 32611 (United States); Tancig, K.J. [PO Box 116455, University of Florida, Gainesville, FL 32611 (United States); Onderdonk, D.A.; Gantz, C.A. [Department of Biology, PO Box 118526, University of Florida, Gainesville, FL 32611 (United States)

    2011-01-15

    Twelve taxa under exploration as bioenergy crops in Florida and the U.S. were evaluated for potential invasiveness using the Australian Weed Risk Assessment system (WRA) modified for separate assessment at the state and national scales. When tested across a range of geographies, this system correctly identifies invaders 90%, and non-invaders 70% of the time, on average. Predictions for Florida were the same as for the U.S. Arundo donax, Eucalyptus camaldulensis, Eucalyptus grandis, Jatropha curcas, Leucaena leucocephala, Pennisetum purpureum, and Ricinus communis were found to have a high probability of becoming invasive, while Miscanthus x giganteus, Saccharum arundinaceum, Saccharum officinarum, and the sweet variety of Sorghum bicolor have a low probability of becoming invasive. Eucalyptus amplifolia requires further evaluation before a prediction is possible. These results are consistent with reports on other tests of these taxa. Given the economic and ecological impacts of invasive species, including the carbon expended for mechanical and chemical control efforts, cultivation of taxa likely to become invasive should be avoided. (author)

  5. Combustion properties, water absorption and grindability of raw/torrefied biomass pellets and Silantek coal

    Science.gov (United States)

    Matali, Sharmeela; Rahman, Norazah Abdul; Idris, Siti Shawaliah; Yaacob, Nurhafizah

    2017-12-01

    Torrefaction, also known as mild pyrolysis, is proven to convert raw biomass into a value-added energy commodity particularly for application in combustion and co-firing systems with improved storage and handling properties. This paper aims to compare the characteristics of Malaysian bituminous coal i.e. Silantek coal with raw and torrefied biomass pellet originated from oil palm frond and fast growing tree species, Leucaena Leucocephala. Biomass samples were initially torrefied at 300 °C for 60 minutes. Resulting torrefied biomass pellets were analysed using a number of standard fuel characterisation analyses i.e. elemental analysis, proximate analysis and calorific content (high heating values) experiments. Investigations on combustion characteristics via dynamic thermogravimetric analysis (TGA), grindability and moisture uptake tests were also performed on the torrefied biomass pellets. Better quality bio-chars were produced as compared to its raw forms and with optimal process conditions, torrefaction may potentially produces a solid fuel with combustion reactivity and porosity equivalent to raw biomass while having compatible energy density and grindability to coal.

  6. Genetic selection and improvement of hard wood tree species for fuelwood production on sodic soil with particular reference to Prosopis juliflora

    Energy Technology Data Exchange (ETDEWEB)

    Goel, V.L.; Behl, H.M. [National Botanical Research Inst., Lucknow (India). Dept. of Tree Biology

    2001-07-01

    This study is part of a research programme on selection and improvement of fast growing tree species suitable for wood fuel production on sodic wastelands (pH 8.6-10.5). Field trials of nine legumes (Acacia auriculiformis, A. nilotica, Albizia lebbeck, A. procera, Dalbergia sissoo, Leucaena leucocephala, Pongamia pinnata, Prosopis juliflora, Pithecellobium dulce) and three other tree species (Azadirachta indica, Eucalyptus tereticornis and Terminalai arjuna) were selected for this study. Prosopis juliflora was the most promising species in terms of its biomass productivity (68.7 t ha{sup -1}) and fuel value index (148.8) after 8-yr of growth. Acacia nilotica ranked second. Intra-specific variations were screened at provenance and individual tree level in order to improve fuelwood production potential of P. juliflora through selection and breeding. Successful populations (gene pools) and individuals (genotypes) were closed and conserved in clonal gardens to produce quality germplasm for plantations on sodic wastelands. Genetic testing, selection and multiplication of selected material are under progress. This will optimise gains in future afforestation programmes on sodic soils. (Author)

  7. Dust collection capacity of plants growing in coal mining areas

    International Nuclear Information System (INIS)

    Maiti, S.K.

    1993-01-01

    Plant can act as living filter of dust pollution in coal mining areas, where the amount of suspended particulate matter and dust fall rate is very high. Therefore, plant species growing in coal mining areas are classified as evergreen or deciduous with simple and compound leaf basis. The dust arresting capacity of each leaf is measured and expressed in g/m 2 . The study indicated that evergreen plants with simple, pilose surface, like - Alstonia, Ficus cunea, F. benghalensis and Mangifera indica are good dust catcher than evergreen compound leaves of Cassia siamea, Acacia arabica and Leucaena leucocephala. Deciduous with simple leaves, such as Zizyphus mauritiana, F. religiosa, Psidium guyava are also good dust collectors. Suitable plant species also help in quick reclamation of mined out areas; one practical difficulty for establishment of trees as green belts or reclamation purpose, has been incidence of cattle grazing. This study suggested a systematic way of selecting plant species on the basis of their efficiency in dust control and resistance to cattle grazing. (author). 16 refs., 3 tabs

  8. CRESCIMENTO DE ESPÉCIES ARBÓREAS EM SOLO SALINO-SÓDICO TRATADO COM ÁCIDO SULFÚRICO

    Directory of Open Access Journals (Sweden)

    Rivaldo Vital dos Santos

    1998-08-01

    Full Text Available RESUMO O trabalho foi conduzido em casa-de-vegetação, com o objetivo de se avaliar a tolerância de mudas de espécies arbóreas cultivadas em solo salino-sódico. O solo, após seco, destorroado, peneirado e homogeneizado, foi colocado em vasos com capacidade para 2U. O experimento envolveu 5 espécies, 2 tratamentos de corretivo e 3 repetições, totalizando 30 vasos e os tratamentos corresponderam à omissão e presença de ácido sulfúrico (2,4ml.vaso-1. As espécies cultivadas foram: algaroba (Prosopis juliflora, leucena (Leucaena leucocephala, sabiá (Mimosa caesalpiniifolia, jucá (Caesalpinia ferrea e tamboril (Enterolobium contorsiliquum. Após 50 dias da germinação constatou-se que a algaroba e o tamboril apresentaram maior crescimento da parte aérea e que a aplicação do ácido sulfúrico no solo acentuou tal resultado.

  9. Temporal Dynamics of Arthropods on Six Tree Species in Dry Woodlands on the Caribbean Island of Puerto Rico

    Science.gov (United States)

    Beltrán, William; Wunderle, Joseph M.

    2014-01-01

    Abstract The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis–Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L. , Bucida buceras L. , Pithecellobium dulce , and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora , (Swartz) De Candolle, Pi. dulce , Leucaena leucocephala , and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. PMID:25502036

  10. POTENCIAL SIMBIOTICO Y EFECTIVIDAD DE HONGOS MICORRIZO ARBUSCULARES DE TRES SUELOS SOMETIDOS A DIFERENTES USOS MYCORRHIZAL SYMBIOTIC POTENTIAL AND EFFECTIVENESS OF THREE SOILS UNDER DIFFERENT USES

    Directory of Open Access Journals (Sweden)

    Sandra Patricia Jaramillo Padilla

    2004-06-01

    Full Text Available Se realizó un experimento bajo condiciones de invernadero para evaluar el potencial simbiótico y la efectividad de hongos micorrizo-arbusculares (HMA en tres suelos de Colombia sometidos a diferentes usos (plantación de palma de aceite con altos insumos, bosque secundario de reforestación y suelo degradado por minería de aluvión. Tal efectividad se refiere al potencial que tienen los HMA nativos de un suelo para desarrollar la simbiosis micorrizal e incrementar el crecimiento y la concentración de P en los tejidos del hospedero. Semillas germinadas de Leucaena leucocephala se sembraron en macetas que contenían una mezcla de suelo y cuarzo como sustrato de crecimiento. El sustrato fue inoculado con alícuotas de cada suelo y un HMA de reconocida efectividad (Glomus aggregatum. Las plantas crecieron durante 49 días. La efectividad simbiótica micorrizal de los suelos se evaluó a través de mediciones frecuentes del contenido foliar de fósforo (P, y al final del período de crecimiento se determinó la masa seca aérea, el contenido total de P en la parte aérea y la colonización micorrizal. La inoculación con G. aggregatum incrementó significativamente el crecimiento de las plantas y la absorción de P con respecto a las plantas inoculadas con alícuotas de los suelos y aquellas no inoculadas. Así mismo, la colonización micorrizal fue muy alta en las raíces inoculadas con G. aggregatum y ausente en los otros tratamientos. Esto significa que en los suelos estudiados hay una muy baja efectividad micorrizal de los HMA y/o bajo contenido de propágulos micorrizales infectivos, lo cual fue corroborado con la técnica del número más probable y el conteo de esporas.An experiment was conducted under greenhouse conditions to evaluate the mycorrizal symbiotic potential and mycorrizal effectiveness of three soils of Colombia exposed to different uses. Germinated seeds of Leucaena leucocephala were transplanted in a growth substrate

  11. Demanda de mano de obra y rentabilidad de bancos forrajeros en Esparza, Costa Rica Labor demand and profitability of fodder banks in Esparza, Costa Rica

    Directory of Open Access Journals (Sweden)

    Luz Yaneth Sánchez Sarmiento

    2010-07-01

    Full Text Available En Esparza (Costa Rica se evaluó la viabilidad de invertir en bancos forrajeros (BF como alternativa de suplementación para vacas en sistema doble propósito durante la época seca (125 días. Se usaron como indicadores de rentabilidad el Valor Presente Neto (VPN y la Tasa Interna de Retorno (TIR. Se realizó un análisis de sensibilidad para el incremento del precio de la leche, los concentrados, la gallinaza y la mano de obra. Los modelos se elaboraron comparando los BF de plantas leñosas perennes de corte y acarreo de Cratylia argentea + caña de azúcar (Saccharum officinarum (BFC y de ramoneo Leucaena leucocephala (BFL vs. suplementos comerciales tipos concentrado y gallinaza. En los BFC se requirieron 71.1 jornales/año y el análisis financiero indicó que son rentables al compararlos con la gallinaza (VPN = US$362.2, TIR = 17% y concentrados (VPN = US$1953.9; TIR=39%. En BFL se requirieron 13 jornales/año y fueron igualmente rentables en comparación con gallinaza (VPN = US$1594.7; TIR = 21% y con concentrados (VPN = US$3619.6; TIR=35%. Los modelos fueron sensibles a la producción y cambios de precios en la leche, gallinaza, concentrados y el valor del jornal. Los BF son una buena alternativa para la suplementación de ganado en la época seca y una importante fuente de empleo en la región; sin embargo, los altos costos de la mano de obra contratada pueden limitar la adopción.We made a financial analysis in order to assess the feasibility to invest in Fodder Banks as an alternative for supplementing animals in dual purpose systems during the dry season (125 days. Models were constructed to compare cutting and carrying of perennial woody fodder banks (Veranera Cratylia argentea + sugar cane (Saccharum officinarum and browsing fodder banks of Leucaena leucocephala with two supplements: concentrates and chicken manure. The indicators used for the financial evaluation of the systems were Net Present Value (NPV and Internal Return Rate

  12. Fungos micorrízicos arbusculares em sistema de aléias no Estado do Maranhão, Brasil Arbuscular mycorrhizal fungi in an alley cropping system in the state of Maranhão, Brazil

    Directory of Open Access Journals (Sweden)

    Camila Pinheiro Nobre

    2010-12-01

    Full Text Available Sistemas em aléias podem consistir numa solução para o uso da terra em regiões do Trópico Úmido. A relação dessa forma de manejo com a dinâmica dos fungos micorrízicos arbusculares (FMA ainda é pouco compreendida. O objetivo desse estudo foi verificar a influência de leguminosas arbóreas em um sistema em aléias na capacidade infectiva e diversidade de FMA nativos em São Luís, Maranhão. Amostras de solo coletadas do sistema em aléias no campus experimental da Universidade Estadual do Maranhão (UEMA - São Luís, em duas épocas do ano (Julho/2006 e Abril/2007, a duas distâncias (0 m e 0,5 m do tronco de três leguminosas (Leucaena leucocephala, Clitoria fairchildiana e Acacia mangium e em área testemunha (sem leguminosas na profundidade de 0 - 20 cm. O solo coletado foi utilizado para avaliar a capacidade infectiva dos FMA nativos, densidade e identificação de glomerosporos. O sistema em aléias aumenta o potencial de infectividade dos FMA nativos dependendo da espécie de leguminosa arbórea associada, estação de coleta e proximidades das árvores. Dezesseis espécies de FMA foram encontradas na área distribuídas em cinco gêneros, sendo Scutellospora o mais representativo.Alley cropping systems may be a solution for land use in tropical regions. How land use is connected to mycorrhizal arbuscular fungi (AMF is poorly understood, especially in the tropics. The aim of this study was to evaluate the influence of leguminous trees in an alley cropping system in regard to the infectivity and diversity of native AMF species in São Luís, Maranhão, Brazil. Soil samples were collected in an experimental area of the Universidade Estadual do Maranhão (UEMA - São Luís, in two seasons (July/2006 and April/2007, two distances (0 m and 0.5 m from the trunk of three leguminous trees (Leucaena leucocephala, Clitoria fairchildiana e Acacia mangium, and in a control area 0-20 cm deep. Soil samples were used to evaluate the

  13. Additions to the flora of Tenerife (Canary Islands, Spain

    Directory of Open Access Journals (Sweden)

    Verloove, F.

    2011-12-01

    Full Text Available Additions to the flora of Tenerife (Canary Islands, Spain.- Recent fieldwork in Tenerife, especially in September 2010, yielded several interesting new records of non-native vascular plants. Bothriochloa ischaemum var. songarica, “Asian” Cardamine flexuosa, Cestrum parqui, Digitaria violascens, Ficus lyrata, Ficus rubiginosa, Hoffmannseggia glauca, Hyparrhenia rufa subsp. altissima, Jacaranda mimosifolia, Merremia tuberosa, Passiflora morifolia, Phytolacca dioica, Schefflera actinophylla and Solanum abutiloides are reported for the first time from the Canary Islands, while Eragrostis barrelieri var. pygmaea, Ficus microcarpa, Ipomoea purpurea, Leucaena leucocephala subsp. glabrata, Sechium edule, Tradescantia zebrina and Turnera ulmifolia are new to the flora of the island of Tenerife. New records of Acacia cyclops, Atriplex suberecta, Heliotropium curassavicum, Paspalum dilatatum, P. notatum, Pluchea ovalis, Pulicaria paludosa, Sclerophylax spinescens and Solanum villosum subsp. miniatum confirm their recent expansion on the island of Tenerife. New records are provided for the recently described Sporobolus copei . Finally, Paspalum vaginatum (hitherto possibly confused with P. distichum and Potentilla indica are confirmed from the island of Tenerife.

    Adiciones para la flora de Tenerife (Islas Canarias, España.- Algunos recientes trabajos de campo en Tenerife, especialmente en Septiembre de 2010, trajeron consigo varias nuevas e interesantes adiciones de plantas vasculares no autóctonas. Bothriochloa ischaemum var. songarica, Cardamine flexuosa “Asiática”, Cestrum parqui, Digitaria violascens, Ficus lyrata, Ficus rubiginosa, Hoffmannseggia glauca, Hyparrhenia rufa subsp. altissima, Jacaranda mimosifolia, Merremia tuberosa, Passiflora morifolia, Phytolacca dioica, Schefflera actinophylla y

  14. Educación basada en el funcionamiento del cerebro

    Directory of Open Access Journals (Sweden)

    Silvia Franco Corso

    2013-06-01

    Full Text Available Introducción: La educación basada en el cerebro es una disciplina que busca maximizar la capacidad de aprender –memoria, atención, entendimiento- a partir de los hallazgos neurocientíficos. Desarrollo: En el siguiente artículo buscamos exponer algunos de los conocimientos de neurociencias y aprendizaje y como estos tienen aplicabilidad en el aula de clase o en general en el proceso de aprendizaje que se va deteriorando con la edad. Conclusión: El dividir la clase en bloques, realizar animaciones para estimulación visual, despertar emociones o exponer primero los conceptos generales antes que los específicos han sido formas eficaces de mejorar el rendimiento de los estudiantes en el aula de clase. La adecuada alimentación, el ejercicio constante, el reforzamiento en la lectura o ejercicios de memoria son clave para estimular el cerebro y prevenir el deterioro cognitivo normal de el envejecimiento.

  15. Forage production and growing goats’ response under silvopastoral systems based on Guazuma ulmifolia, Leucaena leucocephala and Crescentia cujete

    OpenAIRE

    Gustavo Rodríguez Fernández; Belisario Roncallo Fandiño

    2013-01-01

    Grass monoculture, besides being unnatural to goat’s natural eating habits, exhibits low forage production during the dry season, with negative impacts on animal productivity. This research aimed to determine the productive advantages of silvopastoral system arrangements in goat production. A completely randomized design with repeated measurements through time was used. Six treatments were evaluated: kikuyina grass monoculture (Bothriochloa per...

  16. Gastrointestinal nematode infection does not affect selection of tropical foliage by goats in a cafeteria trial.

    Science.gov (United States)

    Ventura-Cordero, J; González-Pech, P G; Jaimez-Rodriguez, P R; Ortíz-Ocampo, G I; Sandoval-Castro, C A; Torres-Acosta, J F J

    2017-01-01

    It is important to determine whether gastrointestinal nematodes (GINs) affect foliage choice of goats leading to confirm the expression of a self-medication behavior. This study investigated the effect of GIN infection on tropical foliage selection by goats. During experimental stage 1 (10 days), goats had a natural mixed GIN infection, and at stage 2 (10 days), goats were treated with effective anthelmintics to maintain them free of GIN infection. During stage 1 the twelve adult goats (32 ± 2.3 kg live weight [LW]) were assigned to three groups (n = 4) according to their initial GIN infection status: HI group, with fecal egg count (FEC) between 1450 and 2150 eggs per g/feces (EPG); MI group, medium FEC (592-1167 EPG); and the NI group, free from GIN infection. Fresh foliage of four tropical plants were offered to goats ad libitum for 1 h daily: Gymnopodium floribundum (high condensed tannin [CT] content, 37-40 %), Mimosa bahamensis (medium CT content, 16-17 %), Leucaena leucocephala (low CT content, 3-5 %), and Viguiera dentata (negligible CT content, 0.6-0.9 %). Jacobs' selection indexes (JSIs) were estimated for the experimental foliage based on dry matter (DM), CT, or crude protein (CP) intake. During both study stages, individual fecal egg counts were estimated. The JSI patterns of different plant species, based on DM, CT, or CP, were similar irrespective of infection level during stage 1 (HI, MI, and NI) or no GIN infection (stage 2). Thus, irrespective of GIN infection, goats actively selected M. bahamensis (high CT, low CP content) and V. dentata (negligible CT, high CP content) but avoided G. floribundum (high CT, low CP content) and L. leucocephala (medium CT and high CP content). Thus, natural GIN infection did not influence goats' foliage selection.

  17. Temporal dynamics of arthropods on six tree species in dry woodlands on the Caribbean Island of Puerto Rico.

    Science.gov (United States)

    Beltrán, William; Wunderle, Joseph M

    2014-01-01

    The seasonal dynamics of foliage arthropod populations are poorly studied in tropical dry forests despite the importance of these studies for understanding arthropod population responses to environmental change. We monitored the abundance, temporal distributions, and body size of arthropods in five naturalized alien and one native tree species to characterize arthropod seasonality in dry novel Prosopis-Leucaena woodlands in Puerto Rico. A branch clipping method was used monthly to sample foliage arthropod abundance over 39 mo. Seasonal patterns of rainfall and abundance within various arthropod taxa were highly variable from year to year. Abundance for most taxa did not show significant seasonality over the 3 yr, although most taxa had abundance peaks each year. However, Homoptera displayed high seasonality with significant temporal aggregations in each year. Formicidae, Orthoptera, and Coleoptera showed high variation in abundance between wet and dry periods, whereas Hemiptera were consistently more abundant in the wet period. Seasonal differences in mean abundance were found only in a few taxa on Tamarindus indica L., Bucida buceras L., Pithecellobium dulce, and (Roxburgh) Benth. Mean arthropod abundance varied among tree species, with highest numbers on Prosopis juliflora, (Swartz) De Candolle, Pi. dulce, Leucaena leucocephala, and (Lamarck) de Wit. Abundance of Araneae, Orthoptera, Coleoptera, Lepidoptera larvae, and all arthropods showed weak relationships with one or more climatic variables (rainfall, maximum temperature, or relative humidity). Body size of arthropods was usually largest during the dry periods. Overall, total foliage arthropod abundance showed no consistent seasonality among years, which may become a more common trend in dry forests and woodlands in the Caribbean if seasonality of rainfall becomes less predictable. © The Author 2014. Published by Oxford University Press on behalf of the Entomological Society of America.

  18. Lógica Difusa Basada en la Experiencia del Usuario para Medir la Usabilidad

    OpenAIRE

    Lionel Rodolfo Baquero Hernández; Osviel Rodríguez Valdés; Febe Ángel Ciudad Ricardo

    2016-01-01

    La mejor forma de crear un aplicación informática usable es realizando un diseño centrado en el usuario, diseñando para y por el usuario, en contraposición a lo que podría ser un diseño centrado en la tecnología o uno centrado en la creatividad u originalidad. Por lo que se puede también afirmar que la mejor forma de que la usabilidad sea medible es que dicha evaluación sea realizada por el usuario de la misma. Este trabajo se propone como objetivo diseñar una lógica difusa basada en la exper...

  19. Population size of Cuban Parrots Amazona leucocephala and Sandhill Cranes Grus canadensis and community involvement in their conservation in northern Isla de la Juventud, Cuba

    Science.gov (United States)

    Aguilera, X.G.; Alvarez, V.B.; Wiley, J.W.; Rosales, J.R.

    1999-01-01

    The Cuban Sandhill Crane Grus canadensis nesiotes and Cuban Parrot Amazona leucocephala palmarum are considered endangered species in Cuba and the Isla de la Juventud (formerly Isla de Pinos). Coincident with a public education campaign, a population survey for these species was conducted in the northern part of the Isla de la Juventud on 17 December 1995, from 06hoo to 10hoo. Residents from throughout the island participated, manning 98 stations, with 1-4 observers per station. Parrots were observed at 60 (61.2%) of the stations with a total of 1320, maximum (without correction for duplicate observations), and 1100, minimum (corrected), individuals counted. Sandhill cranes were sighted at 38 (38.8%) of the stations, with a total of 115 individuals. Cranes and parrots co-occurred at 20 (20.4%) of the stations.

  20. Introducción a la Diagnosis de Fallos basada en Modelos mediante Aprendizaje basado en Proyectos

    Directory of Open Access Journals (Sweden)

    Ramon Costa Castelló

    2016-04-01

    Full Text Available Resumen: La diagnosis de fallos basada en modelos es hoy en día un campo maduro dentro de la ingeniería de control que empieza a formar parte de los planes de estudios de grado y postgrado. Sin embargo, la falta de buenos materiales pedagógicos dificulta el proceso de enseñanza / aprendizaje. En este trabajo se muestra cómo una metodología de aprendizaje basada en proyectos se ha utilizado en las sesiones de laboratorio del curso de Diagnosis y Control Tolerante a Fallos del Máster en Automática y Robótica de la UPC utilizando un sistema real de tres depótodos. Los métodos de detección de fallos basados en observadores y la utilización de residuos estructurados para el aislamiento de fallos son introducidos a los estudiantes desde un punto de vista práctico, por medio de un conjunto de ejercicios que se proponen para alcanzar un conjunto de objetivos de aprendizaje. Palabras clave: Detección ;Diagnóstico, Residuos, Fallo, Aprendizaje basado en Proyectos.

  1. Teorías Económicas de Reciprocidad Basadas en Intenciones

    Directory of Open Access Journals (Sweden)

    Darwin Cortés

    2010-05-01

    Full Text Available Varios experimentos han mostrado recientemente que los individuos exhiben un comportamiento auténticamente recíproco ante interacciones anónimas que se dan una sola vez (“one shot”. Dado que se ha demostrado que la reciprocidad es relevante en varios campos de la economía, han existido varios intentos de modelar el comportamiento recíproco. En este documento se revisan los modelos de reciprocidad basados en intenciones y se presenta un ejemplo de administración de maestros en el sector público, en el cual el gobierno ofrece un esquema de incentivos con el fin de implementar un programa. La estructura del esquema de incentivos está basada en el dilema del prisionero. Los resultados pueden diferir a la teoría convencional, tanto en los juegos simultáneos como en los secuenciales.

  2. Arquitectura de software basada en microservicios para desarrollo de aplicaciones web de la Asamblea Nacional

    OpenAIRE

    López Hinojosa, José Daniel

    2017-01-01

    Proponer una arquitectura de software basada en microservicios para el desarrollo de aplicaciones web en la Coordinación General de Tecnologías de la Información y Comunicación de la Asamblea Nacional del Ecuador. Actualmente, el proceso de desarrollo de software que realiza la Coordinación General de Tecnologías de la Información y Comunicación (CGTIC) de la Asamblea Nacional del Ecuador (ANE) constituye el empleo de una arquitectura de software tradicional o monolítica que ha sido ...

  3. BEHAVIOR ANALYSIS OF TREE LEGUME SPECIES INTRODUCED IN TROPICAL GRASS PASTURES ANÁLISE DO COMPORTAMENTO DE ESPÉCIES LEGUMINOSAS ARBÓREAS INTRODUZIDAS EM PASTAGENS DE GRAMÍNEAS TROPICAIS

    Directory of Open Access Journals (Sweden)

    Janaina Ribeiro Costa

    2007-09-01

    Full Text Available

    The objective of this study was to analyze the behavior of sixteen tree legume species introduced in tropical grass pastures, without seedling protection and in the presence of animals, in three municipalities of Rio de Janeiro State, Brazil. A multivariate factor analysis method was used with sixteen variables related to seven experimental units in the municipalities and ten variables related to leguminous species. The first rotative factor (F1, which explained the highest percentage of the observed variance (62.7%, showed that the Fazenda Santo Antônio experimental unit, in the Itatiaia municipality, presented the highest values for Ca+Mg, N, and Mg, and the lowest value for P (soil sample collected at the beginning of experimental period, while the opposite was observed for Sipa I unit, in the Seropédica municipality. The F1 factor also showed that the species Jurema branca (Mimosa artemisiana and Jurema preta (Mimosa tenuiflora presented the highest values for diameter growth rate of stem and crown, and the lowest percentage of pastured seedlings, while Leucena (Leucaena leucocephala showed the inverse behavior. Results indicate that M. artemisiana and M. tenuiflora present better potential for introduction in tropical grass pastures without seedling protection and without animal exclusion.

    KEY-WORDS: Tree seedling; factor analysis; communality, mimosa; Leucaena.

    O objetivo deste trabalho foi analisar o comportamento de dezesseis espécies leguminosas arbóreas introduzidas em pastagens de gramíneas tropicais, sem proteção das mudas e na presença de animais, em três municípios do estado do Rio de Janeiro. Para isso, utilizou-se a técnica multivariada da análise de fatores, considerando-se dezesseis variáveis relativas a sete unidades experimentais nos municípios e dez vari

  4. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras Soil litter stock and fertility after planting leguminous shrubs and forage trees on degraded signal grass pasture

    Directory of Open Access Journals (Sweden)

    André Barbosa Silva

    2013-04-01

    Full Text Available As pastagens formam a base da pecuária brasileira; essas sofrem degradação em larga escala por deficiência de nitrogênio (N. O consórcio com leguminosas, além de fixar N, pode apresentar outros efeitos na fertilidade do solo como acidificação ou retirada de nutrientes de camadas mais profundas para as mais superficiais. Este trabalho objetivou avaliar o estoque de serapilheira e a fertilidade do solo em pastagens degradadas de braquiária (Brachiaria decumbens, após implantar leguminosas arbustivas e arbóreas forrageiras. Para isso, uma amostragem foi realizada em março de 2010 em um experimento no campo, introduzindo pastagem degradada de Brachiaria decumbens, em julho de 2008, com sabiá (Mimosa caesalpiniifolia, leucena (Leucaena leucocephala, mororó (Bauhinia cheilantha e gliricídia (Gliricidia sepium, além de braquiária adubada e não adubada com N. As amostras de solo e serapilheira foram coletadas aos 0-10, 10-20 e 20-40 cm de profundidade, em três transectos, alternando pontos cobertos por gramíneas e leguminosas, totalizando sete amostras compostas por parcela para determinar pH, P, K, Ca, Mg e Al no solo, enquanto SB, t e m foram calculados. A serapilheira foi separada visualmente em leguminosas, gramíneas e materiais não identificados, em que foram utilizados para quantificação de matéria seca, matéria orgânica, N, P, C, fibra detergente ácido e lignina. A introdução das leguminosas aumentou os teores de N total na serapilheira e reduziu as relações C:N, com destaque para gliricídia e sabiá; entretanto, essa última apresentou elevados teores de lignina. Houve efeito significativo da cobertura por leguminosas, sem diferenças entre essas, para pH e K, na profundidade de 0-10 cm, e para Al e m, aos 10-20 cm de profundidade.Pastures are the fodder supply of Brazilian livestock, and are exhaustively degraded by nitrogen (N deficiency. Intercropping with legumes, aside from nitrogen fixation, may have

  5. Matching species and sites for biomass plantations in Hawaii

    International Nuclear Information System (INIS)

    Phillips, V.D.; Takahashi, P.K.; Singh, D.; Khan, M.A.

    1991-01-01

    Two methods for matching species and sites for biomass plantations in Hawaii were utilized to estimate biomass yields and production costs for Eucalyptus grandis, Eucalyptus saligna, and Leucaena leucocephala. The 'analogous site' method matches the environmental conditions, including soil, rainfall, temperature, and insolation parameters, of well-characterized experimental biomass research sites which produce known yields of these species with similar land areas, or with those areas that can be made similar through soil amendments and improvement, where no field trials exist. The result is the identification of sites with biomass growth, yield, and cost performances which are analogous to the experimental site. The 'regression model' method relates known site-specific biomass productivity with environmental and soil conditions and management practices developed from sites featuring widely different and distinct environmental conditions. Equations then enable the prediction of biomass performance and production costs for each species at any location statewide. The analytical results, using a geographical information system database and the above methods, are presented in map form to expedite the site selection process which indicates expected biomass yield and cost for several fast-growing tropical hardwood species in Hawaii

  6. EFEITO DA SALINIDADE NA GERMINAÇÃO E DESENVOLVIMENTO INICIAL DA LEUCENA

    Directory of Open Access Journals (Sweden)

    Gorgônio Maurício da Nóbrega Neto

    1999-08-01

    Full Text Available RESUMO Este trabalho teve por objetivo avaliar o efeito de diferentes níveis de NaCl na germinação e desenvolvimento inicial da leucena (Leucaena leucocephala (Lam. de Wit.. O experimento foi conduzido em casa-de-vegetação, tendo-se utilizado NaCl para salinização artificial do solo, de modo a se obter as concentrações de 0,15; 0,30; 0,45 e 0,60% (CEesiguais a 6, 12, 18 e 24 dS m-1. Analisaram-se as seguintes variáveis: percentagem de germinação, índice de velocidade de germinação (IVG, área foliar, altura de plantas e matéria seca. A análise dos dados demonstrou que o potencial de germinação da leucena foi afetado com o aumento da concentração de NaCl e que o desenvolvimento inicial da leucena sofreu efeito mais significativo a partir da concentração de 0,45%, mas as variáveis área foliar e matéria seca foram afetadas a partir de 0,15 e 0,30%, respectivamente.

  7. Agro-industrial by-products as roughage source for beef cattle: Chemical composition, nutrient digestibility and energy values of ensiled sweet corn cob and husk with different levels of Ipil – Ipil leaves.

    Directory of Open Access Journals (Sweden)

    Sompong Sruamsiri

    2007-07-01

    Full Text Available This experiment was carried out to determine the nutritive value of agro-industrial by-products and nutrient digestibility of ensiled sweet corn cob and husk with different levels of Ipil - Ipil leaves (Leucaena leucocephala. Four native cattle were assigned by Latin Square Design to receive all dietary treatments in four experimental periods i.e. ensiled sweet corn cob and husk (ESCH, ensiled sweet corn cob and husk + 10 % Ipil - Ipil leaves (ESCH + 10% IL, ensiled sweet corn cob and husk + 20% Ipil - Ipil leaves (ESCH + 20% IL and ensiled sweet corn cob and husk + 30% Ipil - Ipil leaves (ESCH + 30% IL, respectively. Total collection method was used to determine the digestibility coefficients. Results showed that digestibility coefficients in ESCH were low (P>0.05 in all the nutrients. Supplementation of Ipil - Ipil leaves in ESCH increased digestibility coefficients. Total digestible nutrients (TDN and digestible energy were higher in the silages supplemented with Ipil - Ipil leaves. Average TDN contents of ESCH, ESCH + 10% IL, 20% IL and 30% IL were 62.78 + 6.14, 70.41 + 4.04, 72.73 + 2.78 and 63.07 + 4.06 %DM, respectively.

  8. Práctica basada en evidencia en estudiantes de enfermería colombianos

    Directory of Open Access Journals (Sweden)

    María del Pilar Ureña-Molina

    2017-07-01

    Full Text Available Objetivo. Determinar el nivel de competencias sobre Práctica Basada en Evidencia en estudiantes de un programa de Enfermería de Colombia. Materiales y métodos. Mediante un diseño cuantitativo, descriptivo y correlacional, el estudio se desarrolló en 2 fases. La primera fase consistió en la adaptación cultural y validación de contenido del cuestionario de Competencias en Práctica Basada en la Evidencia (CACH-PBE al contexto Colombiano; este instrumento valora tres factores: Actitudes, Habilidades y Conocimientos. En la segunda fase se aplicó el cuestionario a una muestra de 291 estudiantes del Programa de Enfermería de una Universidad de Cúcuta, Colombia, durante el primer semestre del 2016. Resultados. Se encontró un promedio de edad de 20 años, de género femenino en su mayoría, el 57,4 % de ellos no tenía ninguna formación previa sobre PBE y el 57.1 % la había recibido en metodología de investigación. La puntuación global de competencia en PBE fue de 3,58 sobre un máximo de 5, destacando la dimensión Actitudes hacia la PBE con mayor puntuación y la dimensión Conocimientos con menor; encontrándose diferencias estadísticamente significativas a mayor medida en que los estudiantes se encontraban en un semestre superior. Conclusiones. Los estudiantes obtuvieron un nivel medio en competencias para la PBE, asociándose un impacto positivo de la formación académica recibida, ya que en los últimos semestres se evidenció mayor puntuación con respecto a los primeros.

  9. Evaluation of growth performance of broiler chicks fed with raw and processed leucaena eucociphala seed

    International Nuclear Information System (INIS)

    Minari, J.B.; Odutuga, A.A.

    2014-01-01

    Fourty-eight broiler chicks (day-old) were used in a 4 weeks feeding experiment to assess the growth response and the performance of broiler chicks fed raw Leucaena leucociphala seed meal (RLSM), roasted L. leucociphala seed meal (RoLSM) and steamed L. leucociphala seed meal (SLSM). The L. leucociphala seed, which serve as a source of protein were subjected to two treatments (roasting and steaming). Soybean based diet served as the control. There were four (4) experimental groups, each made up of four birds in three replicates allocated to the experimental diets. The results showed that the average final live weight, average weekly weight gain and average feed intake of birds fed with RoLSM performed better than birds fed with RLSM and SLSM. It was observed that the percentage organ to body weight of birds fed with the processed LSM were significantly (P < 0.05), higher as compared to the RLSM. A significant (P < 0.05) increase in the activity of aspartate transferase in the organs (heart, kidney and liver) of broilers fed with RoLSM was observed as compared to those fed with RLSM. The results showed a significant (P < 0.05), reduction in the activity of alanine transferase of organs of broilers chicks fed with processed L. leucociphala compared to the control. It is therefore, concluded that the processing techniques applied were able to improve the nutritional quality of L. leucociphala seed meal but relatively lower to the soybean based meal. (author)

  10. Leucaena allelopathy on weeds and soybean seed germination / Alelopatia de Leucena sobre soja e plantas invasoras

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    Raquel Leszczynski

    2009-07-01

    Full Text Available With the advance of agriculture, there was consequent rising in environment degradation. Therefore, It is interesting the use of plants which have in their chemical composition substances capable of helping in the control of weeds to minimize the use of pesticides. Hence, the objective of this paper was to evaluate solutions of leucena extract on weeds that are frequent on soybean crop. The treatments were leucena extracts at 0, 20, 40, 60, 80 and 100% at room temperature water and water heated to 80°C. The extracts were obtained by crushing 200g of leucena leaves and mixing them with one liter of distilled water with the help of a blender. Seeds were kept in B.O.D. at a temperature of 25°C, with a photoperiod of 12 hours of light. Evaluations were done on a daily basis, from the first to the last day of the experiment, varying according to the species. Results show a negative interference of the extracts, both hot and cold, in the root length of Ipomoea grandifolia, in the percentage of germination and in the root length of Arrowleaf sida and Hair beggarticks. There was no negative interference in the analyzed parameters for soybean seeds. Thus, the results indicate allelopatic potential of Leucaena leuucocephala as an alternative for the management of weeds without interfering on the development of the soybean crop.Com o desenvolvimento da agricultura surgiram os conseqüentes aumentos na degradação ambiental. Assim, estuda-se a utilização de plantas que possuam em sua composição química substâncias capazes de auxiliar no controle de plantas invasoras, amenizando o uso de agrotóxicos. Desta forma, o objetivo do trabalho foi avaliar soluções de extratos de leucena sobre plantas invasoras que freqüentemente ocorrem na cultura da soja. Foram utilizados como tratamentos os seguintes extratos de leucena nas proporções de: 0, 20, 40, 60, 80 e 100% com água à temperatura ambiente e com água aquecida à 80°C. Os extratos foram

  11. Cultivo de milho no sistema de aléias com leguminosas perenes Maize crop in alley cropping system with perennials legumes

    Directory of Open Access Journals (Sweden)

    Luciano Rodrigues Queiroz

    2007-10-01

    Full Text Available Objetivou-se avaliar a influência de algumas leguminosas perenes no teor foliar de N, P e K e na produtividade da cultura do milho (UENF 506-8, cultivado no sistema de aléias, sem adubação fosfatada. Foram realizados experimentos de campo por dois ciclos de cultivo, no Campo Experimental do CCTA/UENF, em Campos dos Goytacazes - RJ. Os tratamentos consistiram no sistema de aléias com Albizia lebbeck (L. Benth., Peltophorum dubium (Spreng. Taub., Leucaena leucocephala (Lam. de Wit., Cajanus cajan (L. Millsp., Sesbania virgata (Cav. Pers., Mimosa caesalpiniaefolia Benth., Gliricidia sepium (Jacq. Pers. e duas testemunhas com milho solteiro (com e sem NPK. Após oito meses de plantio das leguminosas, essas foram podadas, o material foi incorporado ao solo e em seguida semeado o milho nas entrelinhas, com espaçamento de 80 cm entre fileiras. Após 60 dias da semeadura do milho efetuou-se nova poda. No segundo ciclo de cultivo, as práticas culturais foram similares às do primeiro. Foi utilizado o delineamento em blocos casualizados com quatro repetições. Nas aléias de guandu, observou-se milho com maior teor foliar de N, em relação às demais leguminosas, no primeiro ciclo de cultivo. No segundo ciclo, os consórcios milho+guandu, milho+gliricídia e milho solteiro adubado superaram os demais na produtividade de grãos.The objective of this study was to evaluate the effects of perennials legumes, in N, P and K foliar concentration and maize productivity in alley cropping system, without phosphorus fertilization. Field experiments were carried out for two cycles, with legumes intercropping maize (UENF 506-8 in Field Research CCTA/UENF in Campos dos Goytacazes - RJ - Brazil. The treatments consisted of alley cropping system with the species: Albizia lebbeck (L. Benth., Peltophorum dubium (Spreng. Taub., Leucaena leucocephala (Lam. de Wit., Cajanus cajan (L. Millsp., Sesbania virgata (Cav. Pers., Mimosa caesalpiniaefolia Benth., Gliricidia

  12. Modelo de auditoría informática basada en riesgos en ámbitos financieros. Aplicación de un caso de estudio a una cooperativa de ahorro y crédito

    OpenAIRE

    Quishpe Goyes, Bety Elizabeth; Vargas Cisneros, Marjori Silvana

    2013-01-01

    184 hojas : ilustraciones, 29 x 21 cm + CD-ROM 4848 El presente documento tiene como objetivo presentar un modelo que permite efectuar auditorías informáticas basadas en riesgos en ámbitos financieros, el cual fue aplicado a una Cooperativa de Ahorro y Crédito. El modelo propuesto se basa en normas y estándares nacionales e internacionales relacionados con la auditoría informática basada en riesgos, que permiten al auditor informático obtener las referencias necesarias para efectuar el exa...

  13. Desarrollo de una actividad grupal, basada en el uso de internet, para alumnos de ESO

    OpenAIRE

    López de Dios, María Victoria

    2015-01-01

    El presente trabajo Fin de Master, desarrolla el proceso de creación de una metodología didáctica grupal basada en el uso de internet, en concreto una WebQuest, para alumnos de 3º de la ESO, y para la asignatura de Biología y Geología. El tema elegido ha sido "El Chancro del Castaño", y nos hemos basado en un gestor Web de contenidos, denominado Wix.com. Departamento de Bioquímica y Biología Molecular y Fisiología Máster en Profesor de Educación Secundaria Obligatoria y Bachillerato, Fo...

  14. CMIN - herramienta case basada en CRISP-DM para el soporte de proyectos de minería de datos

    Directory of Open Access Journals (Sweden)

    Carlos Cobos

    2010-09-01

    Full Text Available En este artículo se presenta la CMIN, una herramienta CASE (Computer Aided Software Engineering integrada (que soporta todas las fases de un proceso basada en CRISP-DM 1.0 (Cross – Industry Standard Process for Data Mining para soportar el desarrollo de proyectos de minería de datos.Primero se expone la funcionalidad general de CMIN, lo que incluye la gestión de procesos, plantillas y proyectos, y se destaca la capacidad de CMIN para realizar el seguimiento de los proyectos de una forma fácil e intuitiva y la manera como CMIN posibilita que el usuario incremente su conocimiento en el uso de CRISP-DM o de cualquier otro proceso que se defina en la herramienta a través de las ayudas e información que se ofrece en cada paso del proceso. Después, se detalla cómo CMIN permite enlazar en tiempo de ejecución (sin necesidad de volver a compilar la herramienta nuevos algoritmos de minería de datos que apoyen la labor de modelado (basada en un flujo de trabajo o workflow en un proyecto de minería de datos. Finalmente, se ofrecen los resultados de dos evaluaciones de la herramienta, las conclusiones y el trabajo futuro.

  15. Impacto de una intervención breve basada en mindfulness en niños: un estudio piloto

    OpenAIRE

    García Rubio, Carlos; Luna Jarillo, Teodoro; Castillo Gualda, Ruth; Rodríguez Carvajal, Raquel

    2016-01-01

    En la última década el interés por los efectos de la práctica de mindfulness ha sido exponencial. Sin embargo, todavía es escasa la investigación sobre sus efectos en el contexto escolar. Este estudio piloto examinó la efectividad de una intervención breve basada en mindfulness en estudiantes de primaria. Se diseñó un estudio pre-post aleatorizado a nivel de clase con un grupo control. Se investigaron sus efectos sobre distintos síntomas internalizantes y externalizantes, las habilidades de m...

  16. Interfaz humano-computadora basada en señales de electrooculografía para personas con discapacidad motriz

    OpenAIRE

    Daniel Pacheco Bautista; Ignacio Algredo Badillo; David De la Rosa Mejía; Aurelio Horacio Heredia Jiménez

    2014-01-01

    En este trabajo se presenta el desarrollo de un prototipo que asiste, a personas con cierta discapacidad motriz, en la interacción con la computadora de una forma simple y económica, mediante señales de electrooculografía. Esta técnica permite detectar los movimientos oculares basada en el registro de la diferencia de potencial existente entre la córnea y la retina, tal propiedad es aprovechada en este proyecto para controlar el desplazamiento del cursor del ratón de una forma precisa sobre l...

  17. Medicina basada en la evidencia: revisión del concepto

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    Juan Miguel Maestre Uhía

    2013-10-01

    Full Text Available Title: Evidence-based medicine: review of the concept.Resumen:En el presente artículo se revisa el concepto de medicina basada en evidencias (MBE; la MBE es una forma de engranar la mejor evidencia disponible con la pericia y las habilidades individuales del médico; es también una manera de nutrir la práctica médica con datos científicos. Inicialmente se realiza un recorrido por la historia del concepto, seguidamente se hace una revisión de lo que son niveles de evidencia y grados de recomendación, finalmente se describe de manera concisa la forma de hacer MBE. (DUAZARY 2012 No. 2, 159 - 166AbstractThis article reviews the concept of evidence-based medicine (EBM, EBM is a way to engage the best available evidence with the expertise and individual skills of the doctor is also a way to nurture the practice of medicine with scientific data. The thesis begins with a journey through the history of the concept, then we review what levels of evidence are and grades of recommendation, finally concisely describes how to make MBE.Keywords: Evidence-based medicine; patients; research (MeSH

  18. Simulación basada en SMA de sistemas originalmente representados con EDO

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    Ekaitz Zulueta Guerrero

    2011-10-01

    Full Text Available Resumen: En el presente trabajo se expone una metodología para modelar mediante un Sistema Multi-Agente (SMA sistemas biológicos y fisiológicos dinámicos con variables cuantificadas discretas, como el crecimiento y decrecimiento de poblaciones o el modelado epidemiológico de enfermedades. Se muestra un procedimiento para transformar un sistema de Ecuaciones Diferenciales Ordinarias (EDO (que modela un entorno de forma correcta en un SMA equivalente mediante un esquema basado en el método de Monte Carlo. Se utiliza un caso práctico fundamentado en un modelo matemático de Leucemia Mieloide Crónica (LMC para comparar la metodología basada en agentes con el modelado tradicional basado en un sistema de EDO. Se realiza una simulación con cada modelo (SMA y EDO y se compara los resultados obtenidos con ambas metodologías. Palabras clave: Ecuaciones diferenciales, modelo basado en agentes, Monte Carlo

  19. Real-time particle image velocimetry based on FPGA technology;Velocimetria PIV en tiempo real basada en logica programable FPGA

    Energy Technology Data Exchange (ETDEWEB)

    Iriarte Munoz, Jose Miguel [Universidad Nacional de Cuyo, Instituto Balseiro, Centro Atomico Bariloche (Argentina)

    2008-07-01

    Particle image velocimetry (PIV), based on laser sheet, is a method for image processing and calculation of distributed velocity fields.It is well established as a fluid dynamics measurement tool, being applied to liquid, gases and multiphase flows.Images of particles are processed by means of computationally demanding algorithms, what makes its real-time implementation difficult.The most probable displacements are found applying two dimensional cross-correlation function. In this work, we detail how it is possible to achieve real-time visualization of PIV method by designing an adaptive embedded architecture based on FPGA technology.We show first results of a physical field of velocity calculated by this platform system in a real-time approach.;La velocimetria por imagenes de particulas (PIV), basada en plano laser, es una potente herramienta de medicion en dinamica de fluidos, capaz de medir sin grandes errores, un campo de velocidades distribuido en liquidos, gases y flujo multifase.Los altos requerimientos computacionales de los algoritmos PIV dificultan su empleo en tiempo-real.En este trabajo presentamos el diseno de una plataforma basada en tecnologia FPGA para capturar video y procesar en tiempo real el algoritmo de correlacion cruzada bidimensional.Mostramos resultados de un primer abordaje de la captura de imagenes y procesamiento de un campo fisico de velocidades en tiempo real.

  20. Preventing establishment: an inventory of introduced plants in Puerto Villamil, Isabela Island, Galapagos.

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    Anne Guézou

    Full Text Available As part of an island-wide project to identify and eradicate potentially invasive plant species before they become established, a program of inventories is being carried out in the urban and agricultural zones of the four inhabited islands in Galapagos. This study reports the results of the inventory from Puerto Villamil, a coastal village representing the urban zone of Isabela Island. We visited all 1193 village properties to record the presence of the introduced plants. In addition, information was collected from half of the properties to determine evidence for potential invasiveness of the plant species. We recorded 261 vascular taxa, 13 of which were new records for Galapagos. Most of the species were intentionally grown (cultivated (73.3% and used principally as ornamentals. The most frequent taxa we encountered were Cocos nucifera (coconut tree (22.1% as a cultivated plant and Paspalum vaginatum (salt water couch (13.2% as a non cultivated plant. In addition 39 taxa were naturalized. On the basis of the invasiveness study, we recommend five species for eradication (Abutilon dianthum, Datura inoxia, Datura metel, Senna alata and Solanum capsicoides, one species for hybridization studies (Opuntia ficus-indica and three species for control (Furcraea hexapetala, Leucaena leucocephala and Paspalum vaginatum.

  1. Utilização de espécies exóticas na arborização e a facilitação para o estabelecimento de casos de invasão biológica

    Directory of Open Access Journals (Sweden)

    Juliano Ricardo Fabricante

    2017-02-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2017v30n1p55 O presente estudo teve como objetivo inventariar as espécies utilizadas na arborização do campus de Ciências Agrárias (CCA da Universidade Federal da Paraíba (UFPB, Areia, PB e classificá-las de acordo com sua origem e seu potencial invasor. Por meio de caminhadas por toda a área de estudo (busca ativa foram inventariadas todas as espécies utilizadas na arborização local e classificadas em nativas e exóticas. As exóticas ainda foram classificadas quanto ao seu potencial invasor. Ao todo foram identificadas 76 espécies pertencentes a 67 gêneros e 25 famílias. Destas, apenas 26 espécies eram nativas. Os resultados do presente trabalho são preocupantes devido ao elevado número de espécies exóticas utilizadas na arborização do local de estudo (50 spp. e pela presença de espécies reconhecidamente agressivas, a exemplo de Artocarpus heterophyllus Lam., Azadirachta indica A. Juss. e Leucaena leucocephala (Lam. de Wit.

  2. Evaluation of the chemical composition of woody forage silages of the Brazilian semiarid

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    Marcos Deames Araújo Silva

    2015-02-01

    Full Text Available The aim of this work was to evaluate the chemical composition of the woody forage silage in the completely randomized design with six treatments and four replications. The treatments consisted of forage species: Prosopis juliflora, Mimosa tenuiflora, Mimosa caesalpiniifolia, Gliricidia sepium and Leucaena leucocephala. It was found that the silages jurema preta, jucá and sabiá, showed higher levels of DM more than 35 %. Leucena silage presented a higher content of CP (22.40 % and higher pH (5.5, while the algaroba silage presented lowest level of EE (2.83 %. Higher levels of N-NH3 (10.93 % and TDN (66.94 % and lowest content of lignin (3.79 % were found for gliricidia silage. Sabia silage presented a higher content of NDF (64.09%, while its ADF valor (35.54% was similar to jurema preta silage (35.76 %. Algaroba and gliricidia silages presented highest levels of NFC (28.32 and 26.86%, respectively and lower hemicellulose (13.39 and 12.65%, respectively. Leucena and gliricidia silages showed lower levels of cellulose with 14.77 and 15.53%, respectively. The woody forage silages studied in this work shown a good quality and can be used as sources in animal feed.

  3. IN VITRO ANTIMETHANOGENIC PROPERTIES OF SOME PLANTS ADAPTED TO THE FLOODABLE SAVANNA CONDITIONS OF ARAUCA DEPARTMENT, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Oscar Mauricio Velez Terranova

    2015-12-01

    Full Text Available The methanogenic potential and nutritional quality of nineteen plants adapted to the dry and rainy seasons of the Arauca floodable savannas was evaluated. Each plant was incubated anaerobically with rumen fluid at 39 °C for 24h, after incubation period, gas production, methane, volatile fatty acids and dry matter degradation was determined. Among the plants, crude protein values ranged between 6.87-28.22%; neutral detergent fiber was between 35.2 - 71.26%, while the ether extract, ash and nonstructural carbohydrate levels ranged between 1.35 - 6.65, 2.43 - 5.27 and 11.47 - 35.64%, respectively. Gas production and methane were significant correlated (r = 0.84. The species Galactia jussiaeana, Belencita nemorosa, Ambrosia peruviana and Enterolobium schomburgkii showed high values of dry matter degradation (45.40 - 49.13%, VFA (0.84 - 1.37 mmol and low methane production (2.18 - 6.90 ml / g DM degraded. These parameters were similar or better to those found in the species Leucaena leucocephala. The results suggest that these plants present useful compounds to reduce ruminal methanogenesis without affecting the diet digestibility, however further studies are required to assess the persistence of antimethanogenic effect, dosage, consumption and animal performance.

  4. Effect of mixing low palatable grasses of heteropogon contortus with ipil ipil leaves on digestibility in goats

    International Nuclear Information System (INIS)

    Bashir, M.; Qamar, I.A.; Babar, R.

    2015-01-01

    The study was conducted at the National Agricultural Research Centre, Islamabad, Pakistan during 2012 to find out the effect of mixing low palatable grasses of Heteropogon contortus (HC), with tree leaves of Leucaena leucocephala (Ipil ipil, II) in the ratio of 75:25, 50:50, 25:75, along with sole species on their digestibility in small ruminants. Goats fed II/sub 100%/, HC/sub 25%/ II/sub 75%/, HC/sub 50%/ II/sub 50%/, HC/sub 75%/ II/sub 25%/ and HC/sub 100%/ had similar dry matter (DM), crude protein (CP) and crude fibre (CF) consumption among all the treatments. The digestibility percentage of dry matter intake (DMI) varied among the treatments ranging from 68.25% to 41.66%. Mixtures of low palatable grass and Ipil ipil were in general more digestible with more than 65% dry matter digestibility. The lowest digestibility of dry matter (41.66%) was observed in HC/sub 100%/. A similar trend was noted for CP digestibility. However, reverse trend was observed in digestibility of CF where highest digestibility was recorded in HC100% and lowest in II100%. It can be concluded that grass and ipil ipil leaf mixture are better regarding forage quality and nutrient digestibility and can be recommended as animal feed. (author)

  5. Short-rotation forestry for energy production in Hawaii

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, V.C.; Liu, W. [Univ. of Hawaii, Honolulu, HI (United States); Merriam, R.A.

    1993-12-31

    In Hawaii, imports of fossil fuels continue to accelerate and now provide over 90% of the total energy supply at a cost exceeding $1 {times} 10{sup 9} annually exported from the local economy. Concurrently, sugarcane and pineapple crops, the traditional mainstays of the state`s economy, have declined such that as much as 80,000 hectares of agricultural land are now available for alternative land uses. The feasibility of short-rotation forestry for sustainable energy production on these former sugarcane and pineapple plantation lands is being evaluated using species- and site-specific empirical models to predict yields of Eucalyptus grandis, E. saligna, and Leucaena leucocephala, a system model to estimate delivered costs, and a geographic information system to extend the analysis to areas where no field trials exist and to present results in map form. The island of Hawaii is showcased as an application of the methodology. Modeling results of methanol, ethanol, and electricity production from tropical hardwoods are presented. Short-rotation forestry appears to hold promise for the greening of Hawaii`s energy system and agricultural lands for the benefit of the state`s citizens and visitors. The methodology is readily transferable to other regions of the United States and rest of the world.

  6. Cellulose Triacetate Synthesis from Cellulosic Wastes by Heterogeneous Reactions

    Directory of Open Access Journals (Sweden)

    Sherif Shawki Z. Hindi

    2015-06-01

    Full Text Available Cellulosic fibers from cotton fibers (CF, recycled writing papers (RWP, recycled newspapers (RN, and macerated woody fibers of Leucaena leucocephala (MWFL were acetylated by heterogeneous reactions with glacial acetic acid, concentrated H2SO4, and acetic anhydride. The resultant cellulose triacetate (CTA was characterized for yield and solubility as well as by using 1H-NMR spectroscopy and SEM. The acetylated product (AP yields for CF, RWP, RN, and MWFL were 112, 94, 84, and 73%, respectively. After isolation of pure CTA from the AP, the CTA yields were 87, 80, 68, and 54%. The solubility test for the CTA’s showed a clear solubility in chloroform, as well as mixture of chloroform and methanol (9:1v/v and vice versa for acetone. The degree of substitution (DS values for the CTA’s produced were nearly identical and confirmed the presence of CTA. In addition, the pore diameter of the CTA skeleton ranged from 0.072 to 0.239 µm for RWP and RN, and within the dimension scale of the CTA pinholes confirm the synthesis of CTA. Accordingly, pouring of the AP liquor at 25 °C in distilled water at the end of the acetylation and filtration did not hydrolyze the CTA to cellulose diacetate.

  7. PERFORMANCE OF MASHONA COWS REARED ON NATURAL RANGELANDS WITH NON-CONVENTIONAL PROTEIN SUPPLEMENTATION IN THE DRY SEASON, ZIMBABWE

    Directory of Open Access Journals (Sweden)

    Jacob Gusha

    2015-12-01

    Full Text Available Performance of animals in smallholder farming systems is hindered by feed availability and feed costs that make up 60-70% of total variable cost in a farming system. The use of non-conventional feedstuffs is an alternative which can be adopted to minimize feeding costs. The study was conducted to evaluate performance of animals fed with supplements formulated on-farm in comparison with a commercial prepared supplement. Thirty Mashona cows were grouped according to age and subjected to five treatments, given twice a week from the 1st of September until 31st December for three subsequent years. The five treatment diets, beef survival meal (BSM, urea treated maize stover (UTS, Leucaena leucocephala meal (LLM, mixed forage meal (MFM and natural pastures (NP were randomly assigned to cows in a complete randomised design (CRD. Average weight gains were determined. Performance in the first year was not significantly different across treatments. In the subsequent years, performance remained low in the NP. Average weight gains increased in the second and third years and was significantly different across treatments (P<0.05. Performance of animals supplemented with non-conventional feed was comparable to those offered commercial BFM; hence LLM and UTS can be used as alternative protein supplements especially in resource-constrained farming systems. Â

  8. The effect of feeding bull Bali cattle kept in extensive husbandry system with concentrates contained gliricidia sepium leaf meal and banana strach tuber meal on their feed consumption and dried organic matter digestability

    Science.gov (United States)

    Fattah, S.; Sobang, Y. U. L.; Samba, F. D.; Hartati, E.; Kapa, M. M. J.; Henuk, Y. L.

    2018-02-01

    This study aimed to evaluate the effect of feeding bull Bali Cattle kept in extensive husbnadry system with concentrates contained gliricidia sepium leaf meal and banana strach tuber meal in their feed consumptions and dried organic matter digestibility. Three bull Bali cattle aged 1 - 2 years old with an initial body weight of 135.5 kg - 168.0 kg were used in this study. The three treatments used were T0 = local feeds (consisted of Leucaena leucocephala, Acasia leochophloea, and Ficus sp. leaves as commonly used by local farmers); T1 = T0 + 1 kg concentrate (contained banana strach tuber meal + gliricidia sepium leaf meal); T2 = T1 +2 kg concentrate (contained banana strach tuber meal + gliricidia sepium leaf meal). The results showed that the dry matter intake were: 2.40, 3.52, and 4.14; organic matter intake were: 2.17, 3.32, and 3.62; dry matter digestible was 64.63%, 72.45%, 77.28% and organic matter digestible was 66.79%, 74.66%, 79.33% for T0, T1, and T2, respectively. There was no effect (P>0.05) of treatments on the three parameters observed on bull Bali cattle kept in extensive husbandry system and fed with concentrates contained leaf gliricidia sepium meal and banana starch tuber meal.

  9. High carbon stocks in roadside plantations under participatory management in Bangladesh

    Directory of Open Access Journals (Sweden)

    Md. Mizanur Rahman

    2015-01-01

    Full Text Available Plantations are important REDD+strategies for increasing carbon sequestration while enhancing local livelihoods. Reforestation along roads and highways under participatory forest management in southwestern Bangladesh could contribute to REDD+. This study assessed the diversity and structure of roadside plantations in order to develop a basal area based generalized allometric model for estimating above- and below-ground tree biomass carbon in Southwestern Bangladesh. All woody plants with d.b.h. ⩾2cm were identified and their diameters measured in 108 systematically selected zigzag plots of equal size (2×10m. A total of 36 species in 17 families were recorded. Leguminosae accounted for 28% of species and 94% of the total estimated biomass carbon. We estimated a mean stem density of 4528ha−1, basal area of 52.6m2ha−1 and biomass carbon of 192.80 Mg ha−1. Samanea saman, Dalbergia sissoo, Acacia nilotica, and Leucaena leucocephala accounted for most density, basal area, and carbon. We developed and validated three allometric models with equal strength (R2 0.94–0.98 using generalized linear regression. Roadside plantations in Bangladesh can now surely participate in the UNFCCC’s carbon mitigation and adaptation mechanism, but challenges to their long-term sustainability must be addressed.

  10. Preventing Establishment: An Inventory of Introduced Plants in Puerto Villamil, Isabela Island, Galapagos

    Science.gov (United States)

    Guézou, Anne; Pozo, Paola; Buddenhagen, Christopher

    2007-01-01

    As part of an island-wide project to identify and eradicate potentially invasive plant species before they become established, a program of inventories is being carried out in the urban and agricultural zones of the four inhabited islands in Galapagos. This study reports the results of the inventory from Puerto Villamil, a coastal village representing the urban zone of Isabela Island. We visited all 1193 village properties to record the presence of the introduced plants. In addition, information was collected from half of the properties to determine evidence for potential invasiveness of the plant species. We recorded 261 vascular taxa, 13 of which were new records for Galapagos. Most of the species were intentionally grown (cultivated) (73.3%) and used principally as ornamentals. The most frequent taxa we encountered were Cocos nucifera (coconut tree) (22.1%) as a cultivated plant and Paspalum vaginatum (salt water couch) (13.2%) as a non cultivated plant. In addition 39 taxa were naturalized. On the basis of the invasiveness study, we recommend five species for eradication (Abutilon dianthum, Datura inoxia, Datura metel, Senna alata and Solanum capsicoides), one species for hybridization studies (Opuntia ficus-indica) and three species for control (Furcraea hexapetala, Leucaena leucocephala and Paspalum vaginatum). PMID:17940606

  11. Phytostabilization of a Pb-contaminated mine tailing by various tree species in pot and field trial experiments.

    Science.gov (United States)

    Meeinkuirt, Weeradej; Pokethitiyook, Prayad; Kruatrachue, Maleeya; Tanhan, Phanwimol; Chaiyarat, Rattanawat

    2012-10-01

    The potential of 6 tree species (Leucaena leucocephala, Acacia mangium, Peltophorum pterocarpum, Pterocarpus macrocarpus, Lagerstroemia floribunda, Eucalyptus camaldulensis) for phytoremediation of Pb in sand tailings (total Pb >9850 mg kg(-1)) from KEMCO Pb mine in Kanchanaburi province, Thailand, were investigated employing a pot experiment (3 months) and field trial experiment (12 months). In pot study E. camaldulensis treated with Osmocote fertilizer attained the highest total biomass (15.3 g plant(-1)) followed by P. pterocarpum (12.6 g plant(-1)) and A. mangium (10.8 g plant(-1)) both treated with cow manure. Cow manure application resulted in the highest root Pb accumulation (>10000 mg kg(-1)) in L. floribunda and P. macrocarpus. These two species also exhibited the highest Pb uptake (85-88 mg plant(-1)). Results from field trial also showed that Osmocote promoted the best growth performance in E. camaldulensis (biomass 385.7 g plant(-1), height 141.7 cm) followed by A. mangium (biomass 215.9 g plant(-1), height 102.7 cm), and they also exhibited the highest Pb uptake (600-800 microg plant(-1)). A. mangium with the addition of organic fertilizer was the best option for phytostabilization of Pb-contaminated mine tailing because it retained higher Pb concentration in the roots.

  12. Leucaena lanceolata S. Watson ssp. lanceolata, ESPECIE FORESTAL CON POTENCIAL PARA SER INTRODUCIDA EN SISTEMAS SILVOPASTORILES

    Directory of Open Access Journals (Sweden)

    María L. Román-Miranda

    2013-01-01

    Full Text Available La utilización de especies forestales en los sistemas de producción agropecuaria contribuye a reducir la presión en los bosques naturales y se pueden incorporar en áreas no arboladas. El objetivo de este estudio fue evaluar la calidad nutritiva, germinación, desarrollo de plántula en vivero y diversidad de usos de Leucaena lanceolata S. Watson ssp. lanceolata. El material comestible y las semillas se colectaron en Tomatlán, Jalisco. Se realizaron análisis bromatológicos, pruebas de escarificación y evaluación de plántula en vivero sobre tres suelos con diferente pH. El experimento se analizó en un diseño completamente al azar con comparación de medias de Tukey (P ≤ 0.05. Además, se hicieron entrevistas a productores, una revisión bibliográfica y consulta de ejemplares en los herbarios para conocer los usos locales y potenciales de la especie. Los resultados indican alto contenido de materia seca (97.40 % y proteína cruda (29.05 %, mayor germinación en los tratamientos térmicos, mejor desarrollo de la plántula en el suelo ligeramente ácido (6.57 y la diversidad de usos incluye leña, forraje y madera, entre otros. Por el alto valor nutritivo y diversidad de usos en el medio rural, L. lanceolata representa una opción viable para utilizarse en sistemas silvopastoriles del trópico seco.

  13. Potential of tannin-rich plants for modulating ruminal microbes and ruminal fermentation in sheep.

    Science.gov (United States)

    Rira, M; Morgavi, D P; Archimède, H; Marie-Magdeleine, C; Popova, M; Bousseboua, H; Doreau, M

    2015-01-01

    The objective of this work was to study nutritional strategies for decreasing methane production by ruminants fed tropical diets, combining in vitro and in vivo methods. The in vitro approach was used to evaluate the dose effect of condensed tannins (CT) contained in leaves of Gliricidia sepium, Leucaena leucocephala, and Manihot esculenta (39, 75, and 92 g CT/kg DM, respectively) on methane production and ruminal fermentation characteristics. Tannin-rich plants (TRP) were incubated for 24 h alone or mixed with a natural grassland hay based on Dichanthium spp. (control plant), so that proportions of TRP were 0, 0.25, 0.5, 0.75, and 1.0. Methane production, VFA concentration, and fermented OM decreased with increased proportions of TRP. Numerical differences on methane production and VFA concentration among TRP sources may be due to differences in their CT content, with greater effects for L. leucocephala and M. esculenta than for G. sepium. Independently of TRP, the response to increasing doses of CT was linear for methane production but quadratic for VFA concentration. As a result, at moderate tannin dose, methane decreased more than VFA. The in vivo trial was conducted to investigate the effect of TRP on different ruminal microbial populations. To this end, 8 rumen-cannulated sheep from 2 breeds (Texel and Blackbelly) were used in two 4 × 4 Latin square designs. Diets were fed ad libitum and were composed of the same feeds used for the in vitro trial: control plant alone or combined with pellets made from TRP leaves at 44% of the diet DM. Compared to TRP, concentration of Ruminococcus flavefaciens was greater for the control diet and concentration of Ruminococcus albus was least for the control diet. The methanogen population was greater for Texel than for Blackbelly. By contrast, TRP-containing diets did not affect protozoa or Fibrobacter succinogenes numbers. Hence, TRP showed potential for mitigating methane production by ruminants. These findings suggest

  14. Aplicación de traducción basadas en memorias de datos. Desarrollo y perspectivas de futuro

    OpenAIRE

    Muñoz Muñoz, José Manuel; Vella Ramírez, Mercedes

    2010-01-01

    Al hablar de tecnología aplicada a la traducción con frecuencia se establece una distinción entre los conceptos de traducción automática, que se considera un empeño quimérico, y la traducción asistida, a cuyas herramientas de ayuda al traductor se concede gran importancia. En el presente artículo analizamos las tecnologías basadas en la reutilización de segmentos de traducción que tienen su origen en los modelos estadísticos de traducción automática y que surgieron como cons...

  15. Cmin - herramienta case basada en crisp-dm para el soporte de proyectos de minería de datos

    OpenAIRE

    Cobos, Carlos; Zuñiga, Jhon; Guarin, Juan; León, Elizabeth; Mendoza, Martha

    2010-01-01

    En este artículo se presenta la CMIN, una herramienta CASE (Computer Aided Software Engineering) integrada (que soporta todas las fases de un proceso) basada en CRISP-DM 1.0 (Cross – Industry Standard Process for Data Mining) para soportar el desarrollo de proyectos de minería de datos.Primero se expone la funcionalidad general de CMIN, lo que incluye la gestión de procesos, plantillas y proyectos, y se destaca la capacidad de CMIN para realizar el seguimiento de los proyectos de una forma fá...

  16. Gestión de mercado basada en la eficiencia de los procesos de aprendizaje

    Directory of Open Access Journals (Sweden)

    Ma. Cruz Lozano Ramírez

    2016-06-01

    Full Text Available Este documento presenta los resultados de un estudio cuyo objetivo fue identificar la gestión de mercado basada en la eficiencia de la implementación de procesos de aprendizaje en el contexto de estrategias de mercado. El diseño de investigación fue no experimental, correlacional, aplicado a 21 sujetos con funciones dirección en organizaciones de los sectores comercio y servicios. Los resultados de las pruebas explican que la eficiencia de la gestión de mercado está determinada por los procesos de aprendizaje relativos al diseño de estrategias que abordan la ampliación del mercado con servicios especializados e incremento en clientes, beneficios e innovación de productos, programas de promoción y diferenciación de precios.

  17. Social behaviour of cattle in tropical silvopastoral and monoculture systems.

    Science.gov (United States)

    Améndola, L; Solorio, F J; Ku-Vera, J C; Améndola-Massiotti, R D; Zarza, H; Galindo, F

    2016-05-01

    Silvopastoral systems can be a good alternative for sustainable livestock production because they can provide ecosystem services and improve animal welfare. Most farm animals live in groups and the social organization and interactions between individuals have an impact on their welfare. Therefore, the objective of this study was to describe and compare the social behaviour of cattle (Bos indicus×Bos taurus) in a silvopastoral system based on a high density of leucaena (Leucaena leucocephala) combined with guinea grass (Megathyrsus maximus), star grass (Cynodon nlemfuensis) and some trees; with a monoculture system with C. nlemfuensis, in the region of Merida, Yucatán. Eight heifers in each system were observed from 0730 to 1530 h each day for 12 consecutive days during the dry season and 12 consecutive days during the rainy season. The animals followed a rotation between three paddocks, remaining 4 days in each paddock. The vegetation was characterized in the paddocks of the silvopastoral system to estimate the average percentage of shade provided. To make a comparison between systems, we used a t test with group dispersion, and Mann-Whitney tests with the frequency of affiliative and agonistic behaviours. We assessed differences in linearity and stability of dominance hierarchies using Landau's index and Dietz R-test, respectively. The distance of cows with respect to the centroid of the group was shorter, and non-agonistic behaviours were 62% more frequent in the intensive silvopastoral system than in the monoculture one. Heifers in the silvopastoral system had a more linear and non-random dominance hierarchy in both seasons (dry season: h'=0.964; rainy season: h'=0.988), than heifers in the monoculture system (dry season: h'=0.571, rainy season: h'=0.536). The dominance hierarchy in the silvopastoral system was more stable between seasons (R-test=0.779) than in the monoculture system (R-test=0.224). Our results provide the first evidence that heifers in the

  18. Arquitectura Basada en Roles Aplicada en Equipos de Fútbol de Robots con Control Centralizado

    Directory of Open Access Journals (Sweden)

    José G. Guarnizo

    2016-07-01

    Full Text Available Resumen: El fútbol de robots ofrece un entorno adecuado para el diseño y la validación de arquitecturas de sistemas multi-robot. Al clasificar las ligas de fútbol de robots existentes se encuentran ligas con arquitecturas centralizadas que poseen percepción global del entorno y donde los robots son controlados desde un ordenador a través de un único sistema de toma de decisiones. En este artículo se presenta una arquitectura basada en roles para equipos de fútbol de robots con percepción global y control centralizado. En esta arquitectura un rol es seleccionado para cada jugador por medio de una función. A partir de este rol y de las condiciones de juego presentes se selecciona un comportamiento que el jugador deberá ejecutar. La función que es utilizada para la asignación de roles es activada cuando el balón cambia de cuadrante en el campo de juego. La estrategia presentada es comparada en simulación realizando partidos contra un equipo que posee una estrategia de roles constantes y un equipo con una estrategia jerárquica basada en selección de tácticas y posteriormente asignación de roles a partir de la táctica seleccionada. Los resultados mostraron no solo un mejor rendimiento del equipo con la estrategia basada en roles, sino también uniformidad en los comportamientos realizados por los jugadores del equipo durante las transiciones de roles y comportamientos. Abstract: Robot soccer offers an adequate domain in order to design and validate architectures for robot-coordination. One classification refers to centralized architectures, which correspond to robot soccer environments with global perception and centralized control of the robots, using only one decision-making system. In this paper it is presented a centralized robot soccer architecture based on roles, where one role is assigned to each player in order to select a specific behaviour depending on game conditions. Roles

  19. PRÁCTICAS SOSTENIBLES BASADAS EN EL CONOCIMIENTO ANCESTRAL Y LA TECNOLOGÍA. APLICACIÓN EN EL CULTIVO DE MAÍZ

    Directory of Open Access Journals (Sweden)

    Tony JinsopYangüés Pappa

    2012-11-01

    Full Text Available Este trabajo fue desarrollado en la microcuenca Membrillo del cantón Bolívar, provincia de Manabí, su objetivo fue incrementar la productividad del cultivo de maíz aplicando prácticas sostenibles basadas en el conocimiento ancestral y la tecnología. Para lograr el objetivo propuesto se realizó un Diagnóstico Rural Participativo (DRP y se aplicaron las Metodologías de Escuelas de Aprendizaje (ERAs. Entre los principales resultados obtenidos se destacan el incremento de la productividad promedio del cultivo del maíz a 120 qq/ha con prácticas alternativas sostenibles basadas en el conocimiento ancestral y la tecnología en las comunidades donde se aplicaron las experiencias, alcanzando estas mayores ingresos que satisfacen las necesidades de los productores y consecuentemente se logró reducir la presión hacia los bosques por la producción intensiva alcanzada. Se capacitaron a los agricultores involucrados en técnicas de elaboración de bioinsumos que se utilizaron para la producción de maíz, alternativas para el manejo técnico sostenible y amigable con el ambiente en este cultivo. También se demostró que las prácticas implementadas en el desarrollo de este trabajo contribuyen al desarrollo sostenible de la Microcuenca Membrillo.

  20. Aplicación de la enfermería basada en la evidencia en los currículos de pregrado de enfermería en Santander, Colombia

    Directory of Open Access Journals (Sweden)

    Raquel Céspedes Pinto

    2015-05-01

    Full Text Available Introducción: La Enfermería Basada en la Evidencia (EBE, es un movimiento que motiva la investigación y el estudio constante, para incluir la evidencia científica en las decisiones clínicas y de salud. El objetivo de este estudio fue analizar las competencias y componentes disciplinares de la EBE  utilizada en la enseñanza del cuidado en los currículos de los programas de pregrado en enfermería de Santander. Materiales y Métodos: Estudio exploratorio cuantitativo en 69 docentes del área de cuidado y 37 currículos de enfermería de cuatro universidades de Santander. Se diseñaron dos formularios para la recolección de datos, uno para los docentes con 21 ítems para identificar los componentes y competencias utilizadas para la enseñanza del cuidado  y otro para las asignaturas con 12 ítems derivados de dichas dimensiones. Resultados: En la implementación de la EBE en la práctica con los estudiantes para orientar el cuidado, existe diversidad en el empleo que de ésta se hace en las competencias, componentes disciplinares y su desarrollo en las instituciones. Discusión: El estudio mostró que la capacidad de analizar críticamente sobresale como una de las competencias que se fomenta en el estudiante cuando se utiliza la enfermería basada en la evidencia y que las bases de datos de apoyo a la EBE son mínimamente relacionadas en los currículos de las asignaturas de los programas, Conclusiones: Las competencias y conocimientos que requieren los estudiantes de enfermería, para enfrentar el ejercicio de su profesión, aún no se ven sustentadas en las ventajas que puede desarrollar el uso de la enfermería basada en la evidencia, como estrategia para tomar las mejores decisiones en el cuidado de los pacientes.Cómo citar este artículo: Céspedes R. Aplicación de la enfermería basada en la evidencia en los currículos de pregrado de enfermería en Santander, Colombia. Rev Cuid. 2015; 6(1: 900-5. http://dx.doi.org/10

  1. Desarrollo de un plan de marketing digital para una aplicación móvil basada en planes de ocio

    OpenAIRE

    Silva Padilla, Sergio

    2017-01-01

    En este documento se definirá un Plan de Marketing Digital para una idea de negocio presentada en el proyecto de fin de carrera de la ETSIT UPM por Leonor Barrueco en 2015. Dicho proyecto documentaba un plan de negocio para una aplicación móvil basada en planes de ocio llamada LOCALING , pero dejaba pendiente, para una etapa posterior, la definición con más detalle del plan de marketing digital, que es precisamente lo que se desarrollará en el presente Proyecto de Fin de Carrera. Este P...

  2. La capacitación de ventas basada en inventarios críticos como determinante del apalancamiento operativo en farmacia comunitaria

    OpenAIRE

    Rojas, Fernando Alonso; Paniagua, Andrea Tatiana

    2013-01-01

    En el presente documento se cuantifican los efectos de la capacitación de ventas basada en inventariossobre el apalancamiento operativo de una organización de retail farmacéutico. Se seleccionaron productosy temas de capacitación basándose en inventarios críticos de clasificación ABC, ordenados por márgenesde contribución. Los efectos de la capacitación fueron medidos por la optimización de la magnitud delgrado de apalancamiento operativo, y por la correlación lineal de los componentes de res...

  3. Empresa social basada en alianzas.El caso del mercado de saneamiento como modelo de cambio e innovación social

    OpenAIRE

    Flores Castro, Alejandro

    2012-01-01

    Las oportunidades para mejorar la calidad de vida en la base de la pirámide pueden ser capitalizadas, además de la subvención del Estado, por las alianzas de tipo Público-Privado-Social (PPS). El objetivo de este trabajo es diseñar un nuevo modelo de empresa -la empresa social- que cubre lo que el Estado y el sector privado solos no logran alcanzar. La propuesta está basada en alianzas con diferentes stakeholders, y se plantea un modelo de empresa para promover el acceso a servicios de saneam...

  4. Empresa social basada en alianzas. El caso del mercado de saneamiento como modelo de cambio e innovación social

    OpenAIRE

    ALEJANDRO FLORES CASTRO

    2012-01-01

    Las oportunidades para mejorar la calidad de vida en la base de la pirámide pueden ser capitalizadas, además de la subvención del Estado, por las alianzas de tipo Público-Privado-Social (PPS). El objetivo de este trabajo es diseñar un nuevo modelo de empresa -la empresa social- que cubre lo que el Estado y el sector privado solos no logran alcanzar. La propuesta está basada en alianzas con diferentes stakeholders, y se plantea un modelo de empresa para promover el acceso a servicios de saneam...

  5. Autonomía Profesional: factor clave para el ejercicio de la Enfermería Basada en la Evidencia

    Directory of Open Access Journals (Sweden)

    Carolina Luengo Martínez

    Full Text Available El artículo presenta la importancia de la autonomía del profesional de Enferme-ría como factor clave para la implementación de la Enfermería Basada en la Evidencia (EBE. Se analiza el papel fundamental que cumple la EBE como herramienta que permite elevar la calidad y seguridad del cuidado, mejorar los resultados y reducir costos. La autonomía profesional es la que posibilita la aplicación de conocimientos generados a través de la investigación, pero ha sido identificada como una de las principales barreras para la implementación de la EBE.

  6. SIMULADOR INTERACTIVO DE REDES INALÁMBRICAS BASADAS EN IEEE802.11a

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    Arturo Infante Riello

    2010-09-01

    Full Text Available Normal 0 21 false false false ES-TRAD X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Este artículo presenta los fundamentos y características básicas del diseño de un simulador de redes inalámbricas basadas en el estándar IEEE802.11a, mostrando aspectos de la capa física, canal de radio, programación e interfaz de usuario.

  7. Conservación basada en comunidad: importancia y perspectivas para Latinoamérica

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    Pablo Caballero Cruz

    2016-01-01

    Full Text Available Como objetivo se analizaron esquemas de conservación acordes a la realidad de América Latina, tal como la Conservación Basada en Comunidad (CBC. Para ello se empleó una metodología con la que se revisó e integró la información documental relevante del tema. En los resultados del trabajo se reporta en qué consiste la CBC, su relevancia en Latinoamérica y sus temas torales: el socio-ecosistema, la multiescala, los tomadores de decisiones, la apropiación de las estrategias de conservación, las estrategias multi-objetivo, así como las perspectivas de la CBC para América Latina. Las limitaciones y desafíos incluyen saber combinar esto con otras estrategias de conservación, según el contexto. Concluimos que la CBC es una estrategia adecuada, con retos que incluyen su financiamiento, instituciones y cambio en los esquemas federales, que hoy priorizan a las Áreas Naturales Protegidas como estrategia central.

  8. Estudio de variables de gestión del talento humano basada en competencias

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    Abel Del Rio-Cortina

    2016-09-01

    Full Text Available En el presente documento, se desarrolla una aproximación a la ruta de gestión del talento humano basada en competencias aplicada a las Pequeñas Empresas, esto, considerando el talento humano como un dinamizador del proceso organizacional que posibilita el desarrollo de mejoramiento continuo. En este orden de ideas, se requiere del análisis de las características idóneas de impulso a la ruta apropiada de gestión para las Pequeñas Empresas, identificando las características por medio de variables derivadas de una revisión bibliográfica,  tomando como base autores como Vroom (1964, Mallet (1995, Bass (1998, García (1997, Gillezeau (2001, y Etkin (2007. A partir de aspectos comportamentales ligados al ser; Vigotsky (1962, Piaget (1978, Senge (1996, y Delval (2007, en correspondencia con los aspectos del saber; y, finalmente, Morgan (1991, Morín (1994, y Tobón (2006, enfocados en aspectos procedimentales del saber-hacer.

  9. Decaffeination process characteristic of Robusta coffee in single column reactor using ethyl acetate solvent

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    Sukrisno Widyotomo

    2009-08-01

    Full Text Available AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L., Krete (Cassia surattensis (Burm. F., Lamtoro (Leucaena leucocephala L. and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

  10. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins.

    Science.gov (United States)

    Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

    2017-02-04

    Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus , could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p -coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin.

  11. ESTABLISHMENT OF TREE ASSOCIATION WITH CAOBA AND RAMON IN AN ABANDONED QUARRY IN YUCATAN, MEXICO

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    Patricia Montañez Escalante

    2009-02-01

    Full Text Available The influence of the association trees on the height and diameter growth  of mahogany (Swietenia macrophylla King and ramón (Brosimum alicastrum Sw. plantations during the establishment period in an quarry near the city of Merida, Yucatan, Mexico, was evaluated. Associated trees to mahogany were  tamarindo (Tamarindus indica L. and achiote (Bixa orellana L.. Associated trees to ramón were huaxin (Leucaena leucocephala (Lam de Wit. and pixoy (Guazuma ulmifolia Lam.. Tree association effects on the growth in height and diameter of mahogany and ramón were analyzed. The production of fruits and forage in the associated tree species was determined. There were no significant differences in mahogany and ramón diameter and height growth (p> 0.05 among treatments. To associate the ramón with other species of fast growth like huaxin and pixoy pruning was repeatedly conducted on this species to obtain the light levels required for ramón. The forage production of haxin and pixoy was 2 t dry matter ha-1 y-1 and there were not significant differences (p>0.05. The time required to get productive age in the species like ramon and mahogany offer opportunities to use the interspaces during growth period.

  12. Isolation and Molecular Characterization of Potential Plant Growth Promoting Bacillus cereus GGBSTD1 and Pseudomonas spp. GGBSTD3 from Vermisources

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    Balayogan Sivasankari

    2014-01-01

    Full Text Available Vermicompost was prepared from leaf materials of Gliricidia sepium + Cassia auriculata + Leucaena leucocephala with cow dung (1 : 1 : 2 using Eudrilus eugeniae (Kinberg and Eisenia fetida for 60 days. Nineteen bacterial strains which have the capability to fix nitrogen, solubilize inorganic phosphate, and produce phytohormones were isolated from vermicompost, vermisources, and earthworm (fore, mid, and hind guts and tested for plant growth studies. Among the bacterial strains only five strains had both activities; among the five Bacillus spp. showed more nitrogen fixing activity and Pseudomonas spp. showed more phosphate solubilizing activity. Hence these bacterial strains were selected for further molecular analysis and identified Bacillus cereus GGBSTD1 and Pseudomonas spp. GGBSTD3. Plant growth studies use these two organisms separately and as consortium (Bacillus cereus + Pseudomonas spp. in (1 : 1 ratio at different concentrations using Vigna unguiculata (L. Walp. at different day intervals. The germination percent, shoot length, root length, leaf area, chlorophyll a content of the leaves, chlorophyll b content of the leaves, total chlorophyll content of the leaves, fresh weight of the whole plant, and dry weight of the whole plant were significantly enhanced by the consortium (Bacillus cereus + Pseudomonas spp. of two organisms at 5 mL concentrations on the 15th day compared to others.

  13. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

    Science.gov (United States)

    Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

    2017-01-01

    Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin. PMID:28165411

  14. Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

    Directory of Open Access Journals (Sweden)

    Juan Domínguez-Robles

    2017-02-01

    Full Text Available Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.. In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR to analyse the chemical structure, and thermogravimetric analysis (TGA for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA, ferulate (FA and cinnamyl aldehyde end-groups (J were only detected in wheat isolated lignin.

  15. Solar energy efficiency of cocoa clones cultivated under three species of shade trees.

    Directory of Open Access Journals (Sweden)

    Oscar Regazzoni

    2015-04-01

    Full Text Available This experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L., Krete (Cassia surattensis (Burm. F., Lamtoro (Leucaena leucocephala L. and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.

  16. EKSPLORASI HIJUAN PAKAN BABI DAN CARA PENGGUNAANNYA PADA PETERNAKAN BABI TRADISIONAL DI PROVINSI BALI

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    K. Budaarsa

    2015-06-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui jenis-jenis hijauan yang diberikan sebagai pakan ternak babi dan cara penggunaannya di propvinsi Bali. Penelitian dilakukan dengan metode survei di seluruh kabupaten dan kota di Bali. Pengambilan sampel dilakukan dengan teknik stratified random sampling, dengan pengelompokan atas dataran rendah dan dataran tinggi di masing-masing kabupaten dan kota. Pada masing-masing kelompok di ambil 2 orang peternak babi tradisional, sehingga ada 4 peternak yang diwawancarai di masing-masing kabupaten dan kota atau 32 peternak di seluruh Bali. Hasil survei menunjukkan bahwa ada perbedaan hijauan yang diberikan oleh peternak di dataran rendah dan dataran tinggi. Jenis hijauan yang diberikan di dataran rendah antara lain: batang pisang (Musa paradisiaceae, kangkung (Ipomaea aquatica, biah-biah (Limnocharis flava, dan eceng gondok (Eichornia crassipes. Sedamgkan di dataran tinggi antara lain: batang pisang (Musa paradisiaceae, ketela rambat (Ipomaea batatas, daunt alas (Colocasia esculenta daun lamtoro (Leucaena leucocephala dan dag-dagse (Pisonia alba. Batang pisang dominan (95 % diberikan di dataran rendah maupun di dataran tinggi. Pemberian hijauan ada dengan cara direbus ada yang diberikan dalam bentuk segar. Kesimpulan dari penelitian ini adalah terdapat keragaman jenis hijauan pakan babi dan cara pemberiannya antara di dataran rendah dengan dataran tinggi di Bali. Batang pisang merupakan hijauan yang paling banyak digunakan untuk pakan babi pada peternakan babi tradisional, baik pada dataran rendah maupun dataran tinggi.

  17. Level of Coffee Consumption in Urban Community and Its Determinant Factors: Case Study in Jember District

    Directory of Open Access Journals (Sweden)

    Endang Wiji Lestari

    2009-12-01

    Full Text Available AbstractThis experiment aims to know the solar energy efficiency of four clones of cocoa that cultivated under three different shading plants. This experiment has been done from September until December 2013 located at Kaliwining Experiment Farm with characteristic 45 m above sea level, soil type is low humic gley, soil texture is silty clay loam, and climate classification type D based on Scmidht and Fergusson Classification. This experiment used Nested Design as Experimental Design with species of shading plant as main plot which are Teak (Tectona grandis L., Krete (Cassia surattensis (Burm. F., Lamtoro (Leucaena leucocephala L. and Cocoa clones as sub plot which are Sulawesi 1, Sulawesi 2, KKM 22, KW 165. The observation of solar energy efficiency consists of daily solar radiation intensity, solar radiation intensity above plant, solar radiation intensity under plant, and also plant total dry weight. The experimental result showed that there is differences (heterogenity between shading location based on homogenity test by Bartlett Method. There are some interaction between the kind of shading plant and clones in parameter of interception efficiency, absorbtion efficiency, the efficiency of solar energy that caught by plant, and solar energy conversion efficiency. The efficiency of solar energy that caught by plant will affect the solar energy conversion efficiency with R2 = 0,86.  Keywords : Solar Energy Efficiency, Cocoa Clones, Shading Plant, Nested Design, Bartlett Method

  18. Isoflavones hydrolisis and extraction

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    Jozilene Fernandes Farias dos Santos

    2012-12-01

    Full Text Available Isoflavones are found in leguminous species and are used as phytoestrogens widely used by industry for its beneficial effects as estrogens mimicked, antioxidant action and anti-cancer activity. The identification and quantification of isoflavones in plants is a need due to the high demand of industry. Several methods are used for its extraction, using organic solvents (methanol, ethanol and acetonitrile. Samples from five legumes species from Instituto de Zootecnia (IZ, Forage Gene Bank were tested. All seeds received a hydrothermic treatment immersed in pure water at 50°C for 12 hours. Seeds were then oven-dryed. In this work we tested the extraction using only the hydrothermic treatment and hyfrothermic treatment allied to methanol extaction protocol. Seeds were grinded and half of the samples were ressuspended in PBS (phosphate Buffer and the other half were submited to 4 mL of methanol and 1% of acetic acid, soaked for 5 hours, shaked every 15 minutes, at room temperature. The five legume species that we quantify isoflavones by enzyme immunoassay (EIA were: Calopogonium mucunoides, Bauhinia sp., Cajanus cajan, Galactia martii, Leucaena leucocephala. The extraction procedure is a recomendation of AOAC (Association of Official Analytical Chemists for isoflavone quantification. Ours results show an increase of extraction using methanol 80% plus acetic acid 1% and was obtained using solvent extraction in comparison to hydrothermic procedure alone (figure 1.

  19. Effects of alternative protein sources on rumen microbes and productivity of dairy cows

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    Metha Wanapat

    2011-01-01

    Full Text Available This experiment was conducted to investigate the effect of various protein sources on digestibility, rumen fermentation, milk yield and milk composition in dairy cows. Four Holstein Friesian native crossbred cows in early lactating were randomly assigned according to a 4x4 Latin square design. The dietary treatments containing different protein sources in concentrate diets were soybean meal (SBM, cassava hay (CH, Leucaena leucocephala (LL and yeast-fermented cassava chips (YEFECAP, with ad libitum intake of urea-treated rice straw. Digestibility of DM, OM, NDF and ADF was not different among treatments (P>0.05 while CP digestibility was highest (P<0.05 in CH and YEFECAP supplemented groups. Ruminal NH3-N and BUN concentrations varied among protein sources and were highest in SBM and LL fed groups (P<0.05. Ruminal total volatile fatty acid (VFA and propionic acid were found highest in cows receiving CH and YEFECAP (P<0.05. Ruminal fungi, proteolytic and cellulolytic bacteria were highest when YEFECAP was supplemented. Milk fat and milk protein were significantly increased (P<0.05 in cows fed with CH and YEFECAP. Based on this study, it was concluded that providing CH or YEFECAP as protein source in concentrate diets could improve rumen fermentation and milk production in lactating dairy cows fed on rice straw.

  20. Recomendación basada en la evidencia para el manejo inicial del recién nacido con sospecha de sepsis neonatal temprana Utilidad del cuadro hemático en la estimación del riesgo de sepsis neonatal temprana

    OpenAIRE

    Villegas Rosales, Julieta

    2013-01-01

    Objetivo: Estimar las características operativas del recuento total de células blancas, recuento absoluto de neutrófilos y la razón de formas inmaduras a neutrófilos totales por medio de una revisión sistemática de la literatura, con el fin de asistir la formulación de una recomendación basada en evidencia, que utilice el modelo de umbral para el manejo del recién nacido con sospecha de sepsis neonatal temprana. Diseño: Recomendación basada en evidencia para asistir la toma de decisiones en l...

  1. Retribución de directivos basada en opciones y comportamiento frente al riesgo =Option-based executive compensation and risk-taking behavior

    OpenAIRE

    Belda Ruiz, María

    2015-01-01

    La retribución de directivos basada en opciones, comúnmente conocidas como stock options, proporciona incentivos para modificar el perfil de riesgo de la empresa a través de la sensibilidad de la riqueza del directivo a las variaciones en el precio de las acciones de la empresa (delta) y a la volatilidad implícita negociada en el mercado (vega). El objetivo de esta Tesis Doctoral es analizar en detalle estos niveles de incentivos, delta y vega, a través de modelos de valoración que se adaptan...

  2. ESTIMACIÓN DE LA BIOMASA FORESTAL PARA LAS ESPECIES QUERCUS ROTUNDIFOLIA Y QUERCUS SUBER BASADA EN IMÁGENES DEL SATÉLITE QUICKBIRD

    OpenAIRE

    Sousa, Adélia; Marques da Silva, José; Gonçalves, Ana Cristina; Mesquita, Paulo; Silva, Luis; Baptista, F.J.

    2013-01-01

    para una buena gestión. Actualmente las técnicas de inventario y monitoreo de biomasa forestal son usualmente lentas, muy trabajosas y de elevado coste, verificándose así la necesidad de desarrollar otras técnicas, que sean fiables y con costes relativamente reducidos. El objetivo de este estudio es desarrollar una metodología para estimar la biomasa forestal de las especies Quercus rotundifolia y Quercus suber basada en imágenes del satélite QuickBird. La estimación de la biomasa...

  3. El discurso de la formación basada en competencias profesionales. Un análisis crítico de la formación inicial de profesionales en la Educación Superior

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    Eduardo FERNÁNDEZ RODRÍGUEZ

    2009-01-01

    Full Text Available Este trabajo pretende realizar un análisis político del discurso de la formación basada en competencias, a fin de proporcionar elementos de reflexión que rompan con la naturalidad con la que parece haber sido asumido dicho modelo de formación docente en todo el estado. El análisis se estructura en dos partes. En la primera parte se enmarca la formación en competencias dentro de las nuevas formas de organización del trabajo de la economía posfordista, a la vez que se describen los elementos principales en el diseño curricular de una pedagogía basada en el enfoque de las competencias profesionales. En la segunda parte se consideran algunas mitologías asociadas con la formación para la empleabilidad y el aprendizaje en competencias.

  4. Explotación de información de alto valor para la mitigación de vulnerabilidades en operaciones militares basadas en redes

    OpenAIRE

    Tamburri, Adrián Mario; Gilman, Bernardo Marcelo

    2012-01-01

    En las actuales operaciones militares las Fuerzas Armadas de diversos países han adoptado un nuevo paradigma de combate denominado Operaciones Basadas en Redes. Este paradigma basado en el uso intensivo de nuevas tecnologías de la información y redes de comunicación ha cambiado radicalmente la doctrina militar. En el transcurso de estas operaciones, masas de datos e información fluyen libremente entre los actores que componen el escenario de combate. Si bien este paradigma aporta numerosos be...

  5. Aceptabilidad de una intervención basada en Salud Móvil para modificar estilos de vida en prehipertensos de Argentina, Guatemala y Perú: un estudio piloto

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    Andrea Beratarrechea

    Full Text Available Objetivos. Evaluar la aceptabilidad y factibilidad de una intervención basada en salud móvil, para la adopción de estilos de vida saludables en personas prehipertensas que viven en zonas urbanas de bajos recursos en Argentina, Guatemala y Perú. Materiales y métodos. Se reclutaron prehipertensos entre 30 a 60 años para un estudio piloto. La intervención incluyó dos llamadas de consejería realizadas por una nutricionista, seguidas de un mensaje de texto customizado semanal. Una plataforma basada en Internet ofreció el soporte para la implementación de la intervención. Utilizando entrevistas semiestructuradas se evaluó el alcance y la aceptabilidad de esta intervención en los participantes, y la facilidad de uso en las nutricionistas. Resultados. Se logró contactar a 43 de los 45 participantes (95%. El número promedio de llamadas para contactar a un sujeto fue de dos, con un rango de 1-9 llamadas. Dos participantes pudieron ser contactados en su teléfono celular y cinco no recibieron una exposición completa a la intervención. Basados en las entrevistas semiestructuradas, los resultados mostraron una buena aceptabilidad a la intervención en los participantes. Las nutricionistas percibieron a la plataforma como amigable y de fácil manejo. Las barreras para ofrecer esta intervención se relacionaron con dificultades para obtener una señal de telefonía celular adecuada. Conclusiones. Dada la alta penetración de la telefonía celular en países en desarrollo, se concluye que una intervención basada en salud móvil es factible y aceptable para ofrecer una intervención orientada a la modificación del estilo de vida en prehipertensos o personas de alto riesgo de enfermedades crónicas.

  6. LA EVALUACIÓN BASADA EN COMPETENCIAS. SU INCIDENCIA EN LA FORMACIÓN PROFESIONAL DE LA EDUCACIÓN SUPERIOR

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    Lucinda Leonor Vizuete Gaibor

    2016-08-01

    Full Text Available En el presente artículo se realiza una valoración epistemológica de la evaluación basada en competencias profesionales de la educación superior, tomando en cuenta referentes teóricos y concepciones que permiten a los autores llegar a conclusiones acerca de este proceso relacionado con el currículo. El objetivo es analizar los elementos de la evaluación basada en competencias, desde la perspectiva integradora de la formación, priorizando lo que demanda la sociedad del conocimiento en torno al proceso formativo y al desarrollo de las competencias en los estudiantes de la educación superior, evidenciados no solo en el dominio cognitivo sino en la valoración a través de los diversos indicadores del desempeño profesional que determina el grado de formación integral de las competencias profesionales; identificando el logro del aprendizaje significativo de los saberes, el desarrollo metacognitivo, para aportar a la soluciones de los problemas sociales.PALABRAS CLAVE: Competencias; desarrollo metacognitivo; desempeño; dominio cognitivo; evaluación por competencias.THE COMPETENCY-BASED ASSESSMENT AND ITS IMPACT ON THE TRAINING OF HIGHER EDUCATIONABSTRACTIn this article an epistemological assessment of professional competence based assessment of higher education is conducted, taking into account theoretical framework and concepts that allow authors to reach conclusions about this process related to the curriculum. The aim is to analyze the elements of the assessment based on competence, from the integrated perspective of training, prioritizing what society demands knowledge about the training process and the development of skills in students of higher education, evidenced not only in the cognitive domain but in the assessment through various indicators of professional performance which determines the degree of integral formation of professional skills; identifying the achievement of meaningful learning of knowledge, metacognitive

  7. Estrategia Didáctica Lúdica basada en el Computador para Enseñanza de Polinomios en Segundo Año de Educación Básica

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    María Celeste Urbano

    2011-10-01

    Full Text Available El computador como herramienta de cálculo en la aplicación de las técnicas de análisis numérico para encontrar posibles soluciones al uso de recursos computarizados. El objetivo de la presente investigación fue desarrollar estrategias didácticas basadas en el uso del computador para la enseñanza de los polinomios en el segundo año de Educación Básica.

  8. Capacitación Basada en Normas de competencia laboral. Una alternativa para el nuevo milenio en cuestión de capacitación

    OpenAIRE

    Rebeca Schwartzman Kaplan

    2000-01-01

    Considerando el desarrollo científico y tecnológico, así como la globalización de las economías mundiales, hoy la competitividad y la productividad se dan en la capacitación de los recursos como una estrategia de cambio en forma continua y permanente. La capacitación basada en normas de competencia laboral representa una alternativa para hacer de la capacitación tradicional un sistema más eficiente y eficaz a las necesidades actuales, ya que en última instancia son los recursos hu...

  9. Percepción de los empresarios con respecto al cumplimiento de criterios para implantar estrategias basadas en recursos orientadas al crecimiento empresarial en las Pymes de Santiago de Cali - Colombia

    Directory of Open Access Journals (Sweden)

    Adriana Aguilera Castro

    2017-02-01

    Full Text Available El objetivo de este artículo es presentar el análisis de los criterios considerados por empresarios para lograr el crecimiento empresarial desde las estrategias de penetración de mercados, desarrollo de mercados y desarrollo de productos, en las pequeñas y medianas empresas de Santiago de Cali – Colombia, a partir de la perspectiva basada en los recursos. En cuanto a la metodología, se realizó un diagnóstico por medio de la aplicación de un cuestionario, en el que se seleccionaron 27 criterios que representan los indicadores de las estrategias de crecimiento que pueden ser implantadas por las Pymes desde la perspectiva basada en recursos; estos criterios se inscriben dentro de las estrategias de penetración de mercados, desarrollo de mercados y desarrollo de productos. Los resultados indican que los empresarios de las Pymes estudiadas, no utilizan los recursos con “capacidad sobrante” para invertirlos en nuevas áreas de oportunidad que orienten las empresas al crecimiento.

  10. Diseño e implementación de una biblioteca digital distribuida basada en web services para el sector educación

    OpenAIRE

    Bravo Vecorena, Aland; Bravo Vecorena, Aland

    2011-01-01

    El presente trabajo está referido a la creación de una Arquitectura Orientada a Regulaciones para el diseño e implementación de una Biblioteca Digital Distribuida basada en servicios web, para lo cual se ha diseñado e implementado un prototipo base como prueba de concepto, con lo cual se espera servir como referente de mejora metodológica y tecnológica en el sector educativo. ROA es una arquitectura creada por el autor de esta tesis, que se basa en cuatro componentes: Metodologías de direcció...

  11. Electric protections based in microprocessors in power plants; Protecciones electricas basadas en microprocesadores en centrales generadoras

    Energy Technology Data Exchange (ETDEWEB)

    Libreros, Domitilo; Castanon Jimenez, Jose Ismael [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    This article is centered around the substitution of the conventional electric protections of a power plant in connection type unit for protections based in microprocessors. A general model of conventional protection of a power plant is described and the number of analogic and digital signals that intervene in that model are quantified. A model is setup for power plant protection with microprocessors, analyzing each one of the modules that would form it. Finally, the algorithms to carry on such protection are presented. [Espanol] Este articulo se centra en torno a la sustitucion de las protecciones electricas convencionales de una central generadora en conexion tipo unidad por protecciones basadas en microprocesadores. Se describe el modelo general de proteccion convencional de una central generadora y se cuantifica el numero de senales analogicas y digitales que interviene en dicho modelo. Se propone un modelo para proteccion de centrales generadoras mediante microprocesadores, analizandose cada uno de los modulos que lo conformarian. Finalmente, se presentan los algoritmos para realizar dicha proteccion.

  12. Electric protections based in microprocessors in power plants; Protecciones electricas basadas en microprocesadores en centrales generadoras

    Energy Technology Data Exchange (ETDEWEB)

    Libreros, Domitilo; Castanon Jimenez, Jose Ismael [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    This article is centered around the substitution of the conventional electric protections of a power plant in connection type unit for protections based in microprocessors. A general model of conventional protection of a power plant is described and the number of analogic and digital signals that intervene in that model are quantified. A model is setup for power plant protection with microprocessors, analyzing each one of the modules that would form it. Finally, the algorithms to carry on such protection are presented. [Espanol] Este articulo se centra en torno a la sustitucion de las protecciones electricas convencionales de una central generadora en conexion tipo unidad por protecciones basadas en microprocesadores. Se describe el modelo general de proteccion convencional de una central generadora y se cuantifica el numero de senales analogicas y digitales que interviene en dicho modelo. Se propone un modelo para proteccion de centrales generadoras mediante microprocesadores, analizandose cada uno de los modulos que lo conformarian. Finalmente, se presentan los algoritmos para realizar dicha proteccion.

  13. Solución basada en Roip (radio Over Ip) como sistema alternativo o complemrntario para servicios troncalizados de misión crítica

    OpenAIRE

    Riofrío Córdova, Andrés Aníbal

    2015-01-01

    Este trabajo tiene como propósito establecer una solución basada en RoIP (Radio over IP) como un sistema alternativo y/o complementario de comunicaciones vía radio de misión crítica1, especialmente para servicios troncalizados, el objetivo es presentar un medio de comunicaciones que permita integrarse a cualquier red de comunicación de radio frecuencia, considerando un alto nivel de escalabilidad, bajos costos, con poca infraestructura técnica e interoperabilidad con diversas marcas y modelos...

  14. Prácticas basadas en la evidencia: pasado, presente y futuro

    Directory of Open Access Journals (Sweden)

    Alba Elisabeth Mustaca

    2015-04-01

    Full Text Available Las prácticas basadas en la evidencia (PBE y la subclase de ellas, los tratamientos con apoyo empírico (TAE, si bien su nomenclatura es reciente, tienen antecedentes remotos. Se presentan algunos hitos históricos sobre las PBE (pasado y sus antecedentes más próximos, los resultados de las primeras listas que aparecieron de prácticas psicoterapéuticas con apoyo empírico y su comparación con las últimas, como una manera sencilla de evaluar su desarrollo en la psicología clínica (presente. Finalmente, se presentarán algunas de las limitaciones que se deben superar (futuro. Respecto de las primeras listas de PBE, aumentaron las de fuerte apoyo empírico, se agregaron las subcategorías controvertidas y nocivas, presentan TAE para comorbilidades y algunas recomendaciones específicas para cada TAE en particular. Continúa el predominio de las terapias cognitivas-conductuales como las más válidas. Estos resultados muestran un avance considerable en el estudio sistemático de las PBE. En el futuro deberán incrementarse las PBE para comorbilidades, las investigaciones en otros países, las relaciones entre ciencia básica y tecnológica y disminuir la importante disociación que existe entre la investigación, tanto clínica como básica y la práctica profesional, como la cantidad de programas de psicología basados en escuelas psicológicas y bibliografías obsoletas.

  15. The role of short rotation coppice technology in fuelwood supply in Rungwe district, Tanzania

    Directory of Open Access Journals (Sweden)

    G.M. Karwani

    2016-06-01

    Full Text Available The roles of Short Rotation Coppice (SRC Technology in fuelwood supply and offsetting CO2 emissions in the Tanzania and most African countries remain poorly understood. This study was carried in Rungwe District, Mbeya region in Tanzania, to determine trends, extent and drivers of adoption of SRC; identify various sources of household energy and assess the contribution of SRC to the total household fuelwood needs, and trees and shrub species used as sources of fuelwood. Data were collected using reconnaissance, field and social surveys and was analyzed using the Statistical Package for Social Sciences (SPSS. Results revealed that, 97.5% of local community adopted the SRC technology since 1960s. Eucalyptus spp. are mostly planted in woodlots and field boundaries while Persea americana and Leucaena leucocephala are intercropped in farmlands. The survey indicated that out of 176 tons of fuelwood used annually, 73% comes from SRC technology, 25% from non-SRC technology, and only 2% is purchased to supplement household fuelwood shortage. Local communities depend heavily on biomass energy from woodlots and farmlands where tree species like Eucalyptus spp. plays a key role in meeting the energy demand. This study demonstrates that SRC technologies like woodlots, boundary planting, and intercropping in farmland hold high promise to meet the household energy demand. If promoted and backed with strong policies and supportive land tenure, these technologies may reduce the harvesting pressure on native forests for energy demand and contribute to climate change mitigation and adaptation.

  16. VOLUMETRY AND SURVIVAL OF NATIVE AND EXOTIC SPECIES IN THE GYPSUN POLE OF ARARIPE, PE

    Directory of Open Access Journals (Sweden)

    Bruno Coelho de Barros

    2010-12-01

    Full Text Available In the industrial and commercial sectors of the Araripe Region in Pernambuco, Brazil, fire wood is the used in processes of dehydration and production of gypsum with different technologies. Thus, this study aimed to find alternatives to supply the demand of firewood in the Gypsun Pole of Araripe in Pernambuco through the implementation of forest with native and exotic species. The experiment was installed at the Experimental Station of the Agronomic Institute of Pernambuco (IPA, using nine species, both native and exotic: (Imburana - Amburana cearense (Allemão A.C. Sm.; Angico - Anadenanthera colubrina (Vell. Brenan  var. cebil (Griseb. Altschul; Jurema - Mimosa tenuiflora (Willd. Poir.; Sabiá - Mimosa caesalpiniaefolia Benth.; Acácia - Senna siamea (Lam. H.S. Irwin & Barneby; Leucena - Leucaena leucocephala (Lam. R. de Wit.; Algaroba - Prosopis juliflora (Sw. D.C.; Ipês - Tabebuia sp.1 e Tabebuia sp.2. The design was completely randomized with different numbers of replications. The following parameters were evaluated: volume in cubic meter (m³ and stereo meters (st and survival. With regard to the volume in cubic meter, Sabia had the best production. The Jurema and the Sabiá were the heaviest species. In relation to survival, the Ipê 2 and the Imburana had the highest mortalities. Thus, the Sabiá and the Jurema are the species indicated for the production of wood in homogeneous commercial plantations in the Chapada Araripe in Pernambuco.

  17. VOLUMETRIA E SOBREVIVÊNCIA DE ESPÉCIES NATIVAS E EXÓTICAS NO POLO GESSEIRO DO ARARIPE, PE

    Directory of Open Access Journals (Sweden)

    Bruno Coelho de Barros

    2010-01-01

    Full Text Available In the industrial and commercial sectors of the Araripe Region in Pernambuco, Brazil, fire wood is the used in processes of dehydration and production of gypsum with different technologies. Thus, this study aimed to find alternatives to supply the demand of firewood in the Gypsun Pole of Araripe in Pernambuco through the implementation of forest with native and exotic species. The experiment was installed at the Experimental Station of the Agronomic Institute of Pernambuco (IPA, using nine species, both native and exotic: (Imburana - Amburana cearense (Allemão A.C. Sm.; Angico - Anadenanthera colubrina (Vell. Brenan var. cebil (Griseb. Altschul; Jurema - Mimosa tenuiflora (Willd. Poir.; Sabiá - Mimosa caesalpiniaefolia Benth.; Acácia - Senna siamea (Lam. H.S. Irwin & Barneby; Leucena - Leucaena leucocephala (Lam. R. de Wit.; Algaroba - Prosopis juliflora (Sw. D.C.; Ipês - Tabebuia sp.1 e Tabebuia sp.2. The design was completely randomized with different numbers of replications. The following parameters were evaluated: volume in cubic meter (m³ and stereo meters (st and survival. With regard to the volume in cubic meter, Sabia had the best production. The Jurema and the Sabiá were the heaviest species. In relation to survival, the Ipê 2 and the Imburana had the highest mortalities. Thus, the Sabiá and the Jurema are the species indicated for the production of wood in homogeneous commercial plantations in the Chapada Araripe in Pernambuco.

  18. Antibacterial activities of leave extracts as bactericides for soaking of skin or hide

    Science.gov (United States)

    Suparno, Ono; Panandita, Tania; Afifah, Amalia; Marimin; Purnawati, Rini

    2018-03-01

    Antibacteria, a subtance inhibiting the growth of bacteria, can be obtained from tropical-almond (Terminalia catappa), morinda (Morinda citrifolia), and white leadtree (Leucaena leucocephala) plants, since the plants have phytochemical content functioning as antibacterial agent. Commonly, part of plant that contains higher antibacterial substances is its leaf. The objectives of this study were to determine antibacterial activity of tropical-almond, morinda, and white leadtree leaves extracts, and to analyse the potency of the three extracts as natural bactericide for soaking of skin or hide. The responses measured in this study were phytochemical contents, total flavonoid, tannin content, the inhibition zone, the minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC). Phytochemical contents containing the three leaves extracts were alkaloid, flavonoid, tannin, saponin, phenolic, and glycoside. Total flavonoid and tannin contents of the three extracts were tropical-almond extract of 1.14 % and 1.51 %, respectively; morinda extract of 0.61 % and 0.36 %, respectively; and white leadtree extract of 0.60 % and 4.82 %, respectively. White leadtree leaf extract gave the highest inhibition zone against B. subtilis, S. aureus and E. coli, i.e. 1.50, 1.3, and 1.65 cm, respectively; and the lowest MIC and MBC against B. subtilis, S. aureus and E. coli, i.e. 1500, 3000, and 1500 μg/ml, respectively. Therefore, the white leadtree leave extract had more potential as bactericide for soaking of skin or hide compared to those of the tropical-almond and morinda leaves extracts.

  19. Aceites vegetales sobre ácidos grasos y producción de metano in vitro en vacas lecheras.

    Directory of Open Access Journals (Sweden)

    Esperanza Prieto-Manrique

    2016-12-01

    Full Text Available El objetivo de este trabajo fue evaluar el efecto de la adición de aceites vegetales en dietas representativas de vacas lecheras bajo pastoreo, sobre los ácidos grasos, fermentación ruminal y producción de metano in vitro. La investigación se desarrolló en el laboratorio NUTRILAB–GRICA, perteneciente a la Facultad de Ciencias Agrarias, Universidad de Antioquia, Medellín, Colombia, en agosto del 2013. Se utilizó la técnica de producción de gas in vitro. En cuatro dietas (dos de monocultivo en Cynodon plectostachyus y dos de sistema silvopastoril intensivo con Leucaena leucocephala, se evaluó la adición de tres aceites vegetales (girasol, lino y palma a nivel del 2 y 4% de la MS, en un diseño completamente al azar con arreglo factorial de 4x3x2. En todas las dietas, la suplementación con aceite de girasol aumentó el contenido de ácido linoleico (C18:2 c9,12, ácido linoleico conjugado (ALC-c9t11 y ácido transvaccénico (ATV, C18:1 t11 después de la fermentación (p0,05. Ningún aceite afectó la cinética de fermentación, pH, total de ácidos grasos volátiles (AGV, proporción de AGV, ni la producción de metano.

  20. Caracterización bromatológica de seis especies forrajeras en el Valle del Cauto, Cuba

    Directory of Open Access Journals (Sweden)

    Danis M. Verdecia Acosta

    2014-01-01

    Full Text Available Se realizaron seis experimentos simultáneos para determinar la composición bromatológica de leguminosas forrajeras en las condiciones edafoclimáticas del Valle del Cauto, Cuba. Se empleó un diseño en bloques al azar con seis réplicas y los tratamientos fueron las edades de rebrote de 60, 120 y 180 días para los árboles y arbustos ( Leucaena leucocephala, Tithonia diversifolia, Gliricidia sepium y Eritrina varie - gata y de 30, 45, 60, 75 y 90 días para las leguminosas rastreras ( Neonotonia wightii y Te - ramnus labialis , en los periodos lluvioso y poco lluvioso. Se determinaron MS, PB, Ca, P, Mg, Si, FND, FAD, LAD, celulosa, hemicelulosa, contenido celular, ceniza, MO, DIVMS, DV, DISMS, DMO, DFND, DFAD y DPB. Se realizaron análisis de conglomerados para agrupar las especies con características simila - res. Durante el periodo lluvioso se encontraron seis grupos y en el poco lluvioso siete grupos; con los mejores resultados, de forma integral, para la Neonotonia wightii, Teramnus labialis, Gliricidia sepium y Tithonia diversifolia , en el periodo lluvioso; y en el poco lluvioso, para Tithonia diversifolia, Gliricidia sepium y Erythri - na variegata a edades tempranas. Se concluye que la edad presentó un marcado efecto en la composición bromatológica al disminuir la calidad en la medida que la madurez avanza.

  1. Caractéristiques polliniques des plantes mellifères de la zone soudano-guinéenne d'altitude de l'ouest Cameroun

    Directory of Open Access Journals (Sweden)

    Pinta, JY.

    2008-01-01

    Full Text Available Pollen Characteristics of Melliferous Plants of the Soudano Guinean Western Highlands of Cameroon. Between November 2000 and 2001, an inventory and pollen characteristics study of major melliferous plants of the Menoua Division in the Western highlands of Cameroon (Latitude North 5° 21.45N- 5°35.44'N and Longitude east 10°04.72- 10°26.24 were carried out. A total of 78 melliferous plants belonging to 33 families were identified. In terms of number of plants, the most-represented species were Asteraceae (12.9%; Solanaceae (8.6%; Euphorbiaceae (7.6%; Myrtaceae and Malvaceae (6.4% respectively in decreasing order. As concerns pollen characteristics inter and intra families variations were recorded. The smallest pollen size (15.7 ± 1.6 μ was found with Leucaena leucocephala while Calliandra callothyrsus had the highest (190.9 ± 7.1 μ. Subcircular pollen form was predominant (Asteraceae 39.2% of the 78 melliferous plants followed respectively by spheric (20.3%; Convovulaceae, elliptic (12.2%; Dacryodes edulis, cordia sp., and triangular (10.8%; Myrtaceae. Melliferous plants with aperturated exine pollen (Ageratum conyzoides, Psidium guayava were predominant (71.7% compared to those without aperturated exine pollen (Manihot esculenta, Croton macrostachyus; 28.2%. Pollen ornamentation also showed a trend of variation between species. Smooth pollen plants (Arachis hypogaea, Psidium guajava were more numerous (46.1%, followed respectively by spined (25.6%; Asteracea, Malvaceae and scabrous pollen species (Casuarina equisetifolia, Musa paradisiaca.

  2. Sward characteristics and performance of dairy cows in organic grass-legume pastures shaded by tropical trees.

    Science.gov (United States)

    Paciullo, D S C; Pires, M F A; Aroeira, L J M; Morenz, M J F; Maurício, R M; Gomide, C A M; Silveira, S R

    2014-08-01

    The silvopastoral system (SPS) has been suggested to ensure sustainability in animal production systems in tropical ecosystems. The objective of this study was to evaluate pasture characteristics, herbage intake, grazing activity and milk yield of Holstein×Zebu cows managed in two grazing systems (treatments): SPS dominated by a graminaceous forage (Brachiaria decumbens) intercropped with different leguminous herbaceous forages (Stylosanthes spp., Pueraria phaseoloides and Calopogonium mucunoides) and legume trees (Acacia mangium, Gliricidia sepium and Leucaena leucocephala), and open pasture (OP) of B. decumbens intercropped only with Stylosanthes spp. Pastures were managed according to the rules for organic cattle production. The study was carried out by following a switch back format with 12 cows, 6 for each treatment, over 3 experimental years. Herbage mass was similar (P>0.05) for both treatments, supporting an average stocking rate of 1.23 AU/ha. Daily dry matter intake did not vary (P>0.05) between treatments (average of 11.3±1.02 kg/cow per day, corresponding to 2.23±0.2% BW). Milk yield was higher (P0.05) in subsequent years. The highest (P0.05) milk yields. Low persistence of Stylosanthes guianensis was observed over the experimental period, indicating that the persistence of forage legumes under grazing could be improved using adapted cultivars that have higher annual seed production. The SPS and a diversified botanical composition of the pasture using legume species mixed with grasses are recommended for organic milk production.

  3. Pasture species selection for revegetation of open-cut coal mine areas in central Queensland, Australia

    International Nuclear Information System (INIS)

    Naidu, B.P.; Harwood, M.R.; Hacker, J.B.; Thumma, B.R.; Mott, J.J.

    1997-01-01

    This paper outlines a successful approach that was followed to evaluate grass and legume accessions for revegetation of low fertility and saline coal mine spoils. At the first stage, using seed collection records (passport data) of the Australian Tropical Forages Genetic Resource Centre, a range of grasses and legumes adapted to low rainfall, clay soils and saline areas were selected. At the second stage, legume seed was germinated in NaCl solutions of 0 to 0.2 M and salinity tolerance was assessed based on germination percentage and seedling vigour. At the third stage, germination of legumes was assessed in pots filled with mine top-soil and spoils to be revegetated. Grasses were not included in stages 2 and 3 as adequate passport data was available to select a range of accession for the 4th stage. The fourth stage of evaluation comprised field trails of 10 grass and 10 legume accessions, on two top-soils and two spoils. A stoloniferous from of Urochloa mosamblicensis was the most promising grass providing up to 20% of ground cover 12 months after establishment. Legumes surviving at the end of the first season were Desmanthus subulatus, D. virgatus and Neptunia dimorphantha on top-soil and Clitoria ternatea, Leucaena leucocephala, and Rhynchosia sublobata on the spoil. Depending on long term survival, grass and legume accessions will be released as cultivars for minesite revegetation purposes. 14 refs., 4 figs., 3 tabs

  4. Economics of trees versus annual crops on marginal agricultural lands

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, T.; Mohan, D.

    1982-01-01

    The results of a study conducted by the CMA in Rajasthan, selected as one of the major problem states because of its hot, arid and drought-prone character, and its present declining agricultural, livestock and fuelwood production coupled with an expansion of the area under annual crops. The present situation in Rajasthan is described and estimates made of returns from current land based enterprises (annual crops and livestock rearing) in comparison with the expected costs and returns of establishing suitable tree crops in the area. The financial and social feasibility of changing land use from annual to tree crops (while maintaining livestock production) is discussed, together with a consideration of some management and policy issues. Six tree species (Acacia tortilis, Albizzia (Albizia) lebbek, Prosopis cineraria, P. juliflora, Zizyphus species and Leucaena leucocephala) were identified as adaptable for the region and the economics of raising each over 1 felling cycle calculated. Depending on the species and cycle length, net annual returns were Rs 360-3270/ha (using a discount factor of 11%), with an expected return of Rs1680/ha if the species were allocated equally; this is considerably better than the expected returns from annual crops and standing farm trees (Rs-40 to Rs30/ha, with or without including the costs of family labor). Fifteen tables in the text and 9 in appendices give detailed breakdowns of costs and returns. 104 references.

  5. Medida de similitud basada en saliencia

    Directory of Open Access Journals (Sweden)

    Sergio Domínguez

    2012-10-01

    quantifying saliency of feature values, for combining them during a comparison process and, eventually, to weight that feature attending to the result of the combination, are introduced as well. The results for the evaluation of this similarity measure in an image based content retrieval task are presented, as well as their comparison with those obtained using euclidean distance in the same task. Both are validated by volunteers who labelled the retrieved sets. Palabras clave: Bases de datos de imágenes, recuperación basada en contenido, medidas de similitud, modelos perceptuales, análisis de imágenes, Keywords: Image databases, content based retrieval, similarity measures, perceptual models, image analysis

  6. Diseño de un Sistema para la Mejora de la metrología de productos industriales basada en visión artificial

    OpenAIRE

    CAZORLA GARCIA, CRISTIAN

    2015-01-01

    [ES] El objeto del presente TFG es proponer una nueva solución basada en visión artificial para abordar el problema de la medición de objetos en entornos industriales. El alumno tendrá que implementar en un simulador del entorno así como algoritmos de visión con objeto de proporcionar una solución al problema. Por último, tendrá que realizar un estudio de las mejoras que se obtienen con respecto a las utilizadas en industria en la actualidad. Cazorla Garcia, C. (2015). Diseño de un Sistema...

  7. EFECTIVIDAD DEL PROGRAMA EDUCATIVO: “ADOPTANDO UNA DIETA SALUDABLE” BASADA EN ROY EN PREESCOLARES DE LA INSTITUCIÓN EDUCATIVA: “UN NUEVO MUNDO”. PIMENTEL- 2014

    OpenAIRE

    Chirinos Fernández, Jennifer Melissa; Universidad Señor de Sipán; Rodríguez Cabrejos, Iris Janet; Universidad Señor de Sípán

    2015-01-01

     El estudio de tipo cuantitativo tuvo como objetivo determinar la efectividad del programa educativo: Adoptando una dieta saludable basada en Callista Roy en preescolares de la I.E. Un nuevo mundo. El diseño fue cuasi experimental. La población fue no probabilística siendo 60 personas, la muestra fue a conveniencia, distribuyéndose en 2 grupos de 20 preescolares, control y experimental respectivamente. El instrumento utilizado fue el Cuestionario de Valoración Nutricional por dimensiones segú...

  8. Propuesta de una metodología neuroholística basada en los hallazgos de la neurolingüística

    Directory of Open Access Journals (Sweden)

    Pérez Ruiz, Javier

    2013-02-01

    Full Text Available El propósito de este artículo es sugerir una metodología holística para la clase de español como lengua extranjera basada en los hallazgos de la neurolingüística. En primer lugar, la investigación define el concepto de educación holística. En segundo lugar, se exponen las bases neurolingüísticas que apoyarían la mencionada metodología. Y finalmente, se enumeran varias propuestas didácticas para la clase de lenguas extranjeras. La importancia de esta investigación es la novedosa fundamentación didáctica que ofrece, ya que establece un puente entre una metodología sociolingüística y neurolingüística.

  9. Impacto de una intervención breve basada en mindfulness en niños: Un estudio piloto

    Directory of Open Access Journals (Sweden)

    Carlos García Rubio

    2016-01-01

    Full Text Available En la última década el interés por los efectos de la práctica de mindfulness ha sido exponencial. Sin embargo, todavía es escasa la investigación sobre sus efectos en el contexto escolar. Este estudio piloto examinó la efectividad de una intervención breve basada en mindfulness en estudiantes de primaria. Se diseñó un estudio pre-post aleatorizado a nivel de clase con un grupo control. Se investigaron sus efectos sobre distintos síntomas internalizantes y externalizantes, las habilidades de mindfulness y el rendimiento académico. El grupo de mindfulness comparado con el grupo de control disminuyó sus puntuaciones en problemas de conducta, aumentó en relajación y mostró una mejora en sus relaciones sociales. Su rendimiento académico se mantuvo, mientras en el grupo control descendió. Se discuten posibles explicaciones y líneas futuras de investigación.

  10. Análisis del desarrollo social en zonas rurales aisladas empleando simulación basada en agentes

    Directory of Open Access Journals (Sweden)

    Yony Fernando Ceballos

    2014-06-01

    Full Text Available Este documento busca identificar el desarrollo humano y social en áreas rurales donde la energía juega un papel importante en la forma en la cual las personas toman decisiones y su papel en la mejora de la calidad de vida, medida como la satisfacción de las necesidades básicas de Maslow. El modelo de simulación basada en agentes (ABM descrito, en conjunto con los resultados de simulaciones realizadas permite caracterizar y concluir respecto al impacto de la adopción de la energía en el desarrollo de una región rural. El estudio muestra que las comunidades están en capacidad de adaptarse y generar un incremento en la calidad de vida mediante el uso de la energía en la vida diaria, permitiendo mostrar que la adopción de una energía en la zona es una herramienta que posibilita el desarrollo de la región.

  11. Una mejora a la clasificación basada en la medida calidad de la similaridad utilizando relaciones borrosas

    Directory of Open Access Journals (Sweden)

    Yumilka B. Fernández-Hernández

    2015-01-01

    Full Text Available El aprendizaje de reglas de clasificación es un problema clásic o del aprendizaje automático. El algoritmo IRBASIR para la ind ucción de reglas de clasificación basado en relaciones de similaridad per mite descubrir conocimiento a partir de sistemas de decisión qu e contienen rasgos tanto discretos como con tinuos. El mismo ha mostrado obt ener resultados superiores a otro s algoritmos conocidos en este tema. En este artículo se proponen varias modificaciones a este algoritm o basadas en la Teoría de los Conjuntos Borrosos, debido a las ventajas que estos poseen, teniendo en cuenta la medida calidad de similarid ad. Los resultados experimentales muestran que utilizando la Te oría de los Conjuntos Borrosos se obtienen resultados estadísticamente supe riores al algor itmo original.

  12. Gestión y Desarrollo de Proyectos de Software: Metodología Ágil basada en Telecomunicaciones - MATe

    Directory of Open Access Journals (Sweden)

    Marisa Cecilia Tumino

    2013-12-01

    Full Text Available La Metodología Ágil basada en Telecomunica-ciones (MATe es una propuesta metodológica orientada al progreso de emprendimientos informáticos que permite el desarrollo de software por parte de grupos pequeños con escasos recursos. La metodología contempla el trabajo semi-sincrónico, utilizando los adelantos, y las reducciones de costos asociadas en materia de comunicaciones y de recursos tecnológicos, contribuyendo a la fluidez y a la simplicidad del trabajo en un ambiente totalmente virtualizado y libre de gran parte de los costos fijos comunes a una Software factory convencional. Se han rescatado aspectos exitosos de otras metodologías tales como la reunión diaria de Scrum y la programación en parejas de XP, aunque las mencionadas reuniones se desarrollen en salas virtuales y las parejas de programadores residan en lugares distantes.

  13. Doenças da pele em caprinos e ovinos no semi-árido brasileiro Diseases of the skin in sheep and goats from the Brazilian semiarid

    Directory of Open Access Journals (Sweden)

    Juliana T.S.A. Macêdo

    2008-12-01

    Full Text Available Foi realizado um estudo das doenças de pele diagnosticadas em ovinos e caprinos, no semi-árido dos Estados da Paraíba, Pernambuco e Rio Grande do Norte. De janeiro de 2000 a novembro de 2006 foram registrados no Hospital Veterinário da Universidade Federal de Campina Grande, em Patos, Paraíba, 656 diagnósticos em caprinos e 324 em ovinos, além do estudo de espécimes de necropsia ou biópsia da pele de 31 em caprinos e 45 em ovinos enviados para exame histológico. Dos casos atendidos 80 (8,16% apresentavam alterações na pele, destes 35 ocorreram em caprinos (5,33% do total de casos diagnosticados nesta espécie e 45 em ovinos (13,88% dos casos diagnosticados nesta espécie. Das doenças de pele, a mais freqüente foi a miíase (10 casos em caprinos e 7 em ovinos seguida do ectima contagioso (8 casos em caprinos e 2 em ovinos, carcinoma epidermoide (4 casos em caprinos e 5 em ovinos, dermatofilose (8 casos em ovinos, dermatite alérgica (1 caso em ovino e 1 em caprino. Além disso, foram diagnosticados dois casos de pitiose em ovinos, dois casos de epidermólise bolhosa em caprinos, um caso de intoxicação por Brachiaria brizantha (fotossensibilização e outro de intoxicação por Leucaena leucocephala (alopecia em ovinos e um caso de papilomatose, um de pênfigo foliáceo, um de prototecose e um de rabdomiossarcoma em caprinos. Em 4 casos em ovinos e 19 em caprinos não foi realizado diagnóstico etiológico da doença. A informação gerada sobre a ocorrência e epidemiologia das doenças de pele permite estabelecer medidas adequadas de controle.A study of the skin diseases in sheep and goats in the semiarid of the states of Paraíba, Pernambuco and Rio Grande do Norte, Northeastern Brazil was performed. From January 2000 to November 2006, 656 cases in goats and 324 in sheep were presented to the Veterinary Hospital of the Federal University of Campina Grande in Patos, Paraíba. Additionally mailed in biopsy or necropsy skin samples

  14. Chemical composition, “in vitro” digestibility and production of woody forage legumes cultivated in sandy soils Composição bromatológica, digestibilidade "in vitro" e produção de biomassa de leguminosas forrageiras lenhosas cultivadas em solo arenoso

    Directory of Open Access Journals (Sweden)

    Edimilson Volpe

    2009-09-01

    Full Text Available Considering the nutritional value and productivity of woody forage legumes Albizia lebbeck, Cajanus cajan, Cratylia argentea, Gliricidia sepium e Leucaena leucocephala, to be used in supplementation of cattle as a bank protein, five species in Quartzpisament were evaluated. The experiment was conducted from March 2006 to October 2007. The evaluations were carried out in two periods (rainy and dry, with two cuts by period. There was no difference in the accumulation of dry matter, in rainy period. In the dry evaluation, A. lebbeck and C. argentea were higher than the other legumes. The C. cajan was not recovered after the rainy period, which resulted in a low accumulation of dry matter in the dry period. The leaves of Albizia lebbeck showed the highest levels of crude protein in cuts evaluated (210 to 212 g/kg. The in vitro digestibility of dry matter in the leaves of A. lebbeck was significantly higher, with average values of 568g/kg. A. lebbeck, Cratylia argentea and Gliricidea sepium showed the highest content for digestibility of the thin stem. The A. lebbek and C. argentea presented higher accumulation of dry matter (19,3 and 24,3 t DM/ha, respectively and, still, the best values for the qualitative characteristics. Both species are the most promising and adapted to the formation of protein banks in these types of soils.Com o objetivo de avaliar o valor nutritivo e a produtividade das leguminosas forrageiras lenhosas: Albizia lebbeck (Albízia, Cajanus cajan (Feijão-Guandu, Cratylia argentea (Cratília, Gliricidia sepium (Gliricídia e Leucaena leucocephala (Leucena, a serem utilizadas na suplementação de bovinos como banco de proteína, conduziu-se um experimento em Neossolo Quartzarênico. O experimento foi realizado entre março de 2006 e outubro de 2007. As avaliações foram realizadas em dois períodos (chuvoso e seco, com dois cortes para cada período. Não houve diferença no acúmulo de matéria seca nos cortes do per

  15. Nota técnica: Comportamiento productivo de machos Holstein x Cebú en silvopastoreo Technical note: Productive performance of Holstein x Zebu males under silvopastoral system conditions

    Directory of Open Access Journals (Sweden)

    L Simón

    2009-06-01

    Full Text Available Con el objetivo de caracterizar el comportamiento productivo de machos de doble propósito Holstein x Cebú se realizó un experimento durante 288 días, en el cual se seleccionaron 32 añojos de 12 meses de edad, que fueron distribuidos aleatoriamente en cuatro grupos de ocho animales cada uno, pertenecientes a los genotipos: F1 (H x C, Siboney mestizo, Siboney y Mambí, los cuales pastorearon en un silvopastoreo constituido por Leucaena leucocephala y Panicum maximum cv. Likoni dividido en 10 cuartones. Se empleó una carga de tres animales/ha, los cuales se pesaron mensualmente para determinar los cambios de peso vivo, las ganancias y la invasión de garrapatas. Se determinó la disponibilidad de MS y la composición química del pastizal para el período lluvioso y el poco lluvioso. Se encontraron diferencias significativas en la ganancia de peso; los valores fueron de 0,691ª: 0,472b: 0,363b y 0,370b para F1, Siboney mestizo, Siboney y Mambí, respectivamente. Similar respuesta se obtuvo en el conteo de garrapatas, donde F1 resultó significativamente inferior al resto (3,83ª; 7,63b; 8,18b y 8,63b para cada genotipo. De acuerdo con los resultados las mejores ganancias se obtuvieron en el F1, seguido de Siboney mestizo, Siboney y Mambí. Además la menor cantidad de garrapatas se encontró en el F1, vinculado al menor porcentaje de sangre Holstein y al mayor grosor de la piel, lo cual puede ser una característica adecuada para valorar la resistencia de los bovinos a la invasión de las garrapatas.With the objective of characterizing the productive performance of double purpose Holstein x Zebu bulls, a trial was conducted for 288 days, in which 32 twelve-month-old yearlings were selected and randomly distributed in four groups of eight animals each, belonging to the genotypes: F1 (H x Z, crossbred Siboney, Siboney and Mambí, which grazed in a silvopastoral system constituted by Leucaena leucocephala and Panicum maximum cv. Likoni, divided

  16. Efecto del tipo y contenido de aceites esenciales sobre las propiedades mecánicas y barrera de películas comestibles basadas en zeína

    OpenAIRE

    Marzo Rojas, Irene

    2010-01-01

    Las películas comestibles basadas en zeína presentan importantes aplicaciones potenciales para su utilización en alimentos. Sin embargo, la necesidad de añadir aditivos como los plastificantes para mejorar sus propiedades provocan cambios en las propiedades físicas de las películas. Un complemento al uso de plastificantes puede ser el empleo de aceites esenciales pues su aplicación en las películas comestibles es por el momento limitada y además aportaría ya conocidas propie...

  17. Macroproyecto: validación de propuesta educativa con investigación basada en diseño (caso: contenido no lineal. concepto: la materia y sus propiedades)

    OpenAIRE

    Jiménez Sarmiento, Luz Adriana

    2014-01-01

    El presente trabajo de investigación Validación de Propuesta Educativa con investigación basada en diseño para la enseñanza del concepto la materia y sus propiedades a través de la plataforma virtual http://luza1398.wix.com/aventurasescolares, tuvo como finalidad profundizar en las prácticas educativas de enseñanza y aprendizaje, innovando con una metodología que permitiera minimizar con el desinterés y apatía de los estudiantes de grado tercero por las labores escolares. The present...

  18. A preliminary study of cross-amplified microsatellite loci using molted feathers from a near-threatened Painted Stork (Mycteria leucocephala) population of north India as a DNA source.

    Science.gov (United States)

    Sharma, Bharat Bhushan; Banerjee, Basu Dev; Urfi, Abdul Jamil

    2017-11-21

    In continuation of an earlier study in which we reported the cross-amplification of Wood stork microsatellites on the DNA obtained from molted feathers of Painted stork (Mycteria leucocephala), here we investigated the nature of cross-amplified microsatellites and the effect of non-invasive samples on cross-amplification success. In a limited manner, we also addressed the genetic diversity and differentiation in a north Indian population of the Painted Stork examined over three nesting seasons. Among the nine cross-amplified loci, only 5 were polymorphic. Three and 6 loci exhibited low ( 80), respectively. For 36 of 145 samples most of the loci failed to amplify. For genetic diversity, only 3 loci could be used since others exhibited low amplification and linkage disequilibrium. Probability of identity (0.034) was not low enough to develop a confidence that the similar genotypes originate from the same individual. Forty-two unique genotypes were identified. In 3 loci, a low to moderate level of genetic diversity (mean He = 0.435) was reported. Non-significant Fst (0.003, P = 0.230), G'stH (0.005, P = 0.247) and Dest (0.003, P = 0.250) values indicate a lack of structuring in temporally distributed populations of Delhi Zoo. The limitations and uniqueness of this study are discussed.

  19. Interfaz humano-computadora basada en señales de electrooculografía para personas con discapacidad motriz

    Directory of Open Access Journals (Sweden)

    Daniel Pacheco Bautista

    2014-05-01

    Full Text Available En este trabajo se presenta el desarrollo de un prototipo que asiste, a personas con cierta discapacidad motriz, en la interacción con la computadora de una forma simple y económica, mediante señales de electrooculografía. Esta técnica permite detectar los movimientos oculares basada en el registro de la diferencia de potencial existente entre la córnea y la retina, tal propiedad es aprovechada en este proyecto para controlar el desplazamiento del cursor del ratón de una forma precisa sobre la pantalla de la computadora. El prototipo es un diseño compacto alimentado de una fuente única de 5V proveniente del puerto USB y utiliza la circuitería ya implementada en cualquier ratón electromecánico convencional con mínimas modificaciones. El uso de tales dispositivos así como de electrodos convencionales hace el producto de un costo relativamente bajo en relación a las propuestas en otros trabajos.

  20. Empresa social basada en alianzas. El caso del mercado de saneamiento como modelo de cambio e innovación social

    Directory of Open Access Journals (Sweden)

    ALEJANDRO FLORES CASTRO

    2012-01-01

    Full Text Available Las oportunidades para mejorar la calidad de vida en la base de la pirámide pueden ser capitalizadas, además de la subvención del Estado, por las alianzas de tipo Público-Privado-Social (PPS. El objetivo de este trabajo es diseñar un nuevo modelo de empresa -la empresa social- que cubre lo que el Estado y el sector privado solos no logran alcanzar. La propuesta está basada en alianzas con diferentes stakeholders, y se plantea un modelo de empresa para promover el acceso a servicios de saneamiento sostenible de calidad, a partir de incluir el cambio como elemento sustancial con el fin de lograr un paradigma nuevo en la concepción del acceso a servicios de saneamiento en la base de la pirámide.

  1. Instrucción basada en estrategias con mediación tecnológica para mejorar la comprensión lectora en inglés de estudiantes universitarios

    OpenAIRE

    Ochoa-Velasquez, Miguel A.

    2016-01-01

    El propósito de esta investigación educativa fue inquirir sobre los factores que contribuyen a una adquisición más efectiva del idioma inglés, específicamente, el de la competencia comunicativa de comprensión lectora relacionado con el nivel B1 según el Marco Común Europeo de Referencia para las Lenguas Extranjeras (MCERL), a partir de la implementación de una metodología instruccional basada en estrategias de aprendizaje del lenguaje en un ambiente multimodal de contexto universitario. La pr...

  2. Determination of Tropical Forage Preferences Using Two Offering Methods in Rabbits

    Directory of Open Access Journals (Sweden)

    A. M. Safwat

    2014-04-01

    Full Text Available Two methods of feed preference trials were compared to evaluate the acceptability of 5 fresh foliages: Leucaena leucocephala, Moringa oleifera, Portulaca oleracea, Guazuma ulmifolia, and Brosimum alicastrum that was included as control. The evaluation included chemical analyses and forage intake by rabbits. The first method was a cafeteria trial; 12 California growing rabbits aged 8 wk, allocated in individual cages, were offered the five forage plants at the same time inside the cage, while in the second trial 60 California growing rabbits aged 8 wk, allocated individually, were randomly distributed into 5 experimental groups (n = 12/group; for each group just one forage species was offered at a time. The testing period for each method lasted for 7 d, preceded by one week of adaptation. The results showed that B. alicastrum and L. lecocephala were the most preferred forages while on the contrary G. ulmifolia was the least preferred one by rabbits. The results also revealed that the CV% value for the 2nd method (16.32%, which the tested forages were presented separately to rabbits, was lower and methodologically more acceptable than such value for the 1st method (34.28%, which all forages were presented together at the same time. It can be concluded that a range of tropical forages were consumed in acceptable quantities by rabbits, suggesting that diets based on such forages with a concentrate supplement could be used successfully for rabbit production. However, growth performance studies are still needed before recommendations could be made on appropriate ration formulations for commercial use.

  3. Forage Production Technology Transfer in Kwale and Kilifi Districts of Coast Province

    International Nuclear Information System (INIS)

    Mwatate, C.D; Ramadhan, C.D.A; Njunie, M.N

    1999-01-01

    A forage production and utilisation programme was introduced in Kwale (AEZ CL2/CL3) and Kilifi (AEZ CL3/CL4) districts to combat major constraint in low quality and quantity feed at the coast. Dairy production had a great market potential stimulated by the high urban and rural population. Willing farmers were invited to PRC-Mtwapa to see how grasses, legumes and multipurpose trees would fit in their mixed maize cassava farming system. After explaining the forage characteristics to the farmers, they were allowed to select a maximum of three out of eight legumes (Vigna Unguiculata; Dolichos lablab; Clitoria tanatea; Stylosanthes guianennsis; Mucuna pruriens; Pueraria phaseloids; Macroptlium atropurpureum and Centrosema pubescens), tree out of five Napier grasses (Cultivar Mott, Clone 13, French Cameroon, Gold Coast and Bana). Giant panicum and and one of the two multipurpose trees (Gliricidia sepium and Leucaena leucocephala) to test in their farms. After planting in mid 1996 on-farm the research-extension team monitored ground cover and labor aplied monthly by gender, green leaf production, and survival over the drought in 1997. Along-side the planted forages, actual forage fed by dairy farmers was sampled, analysed for chemical composition and degradability to advise farmers on ration formulation. Ranking by farmers showed a preference for clitiria, Macuna and Dolichos in Kwale as the three best legumes. More than 70% of Napier grass variety had established while establishment rate of gliricidia was 33%. An extension leaflet developed during the study will be used to disseminate the information in the region

  4. Diseño de una interfaz basada en la detección de gestos para cirugía laparoscópica asistida por la mano

    OpenAIRE

    De-Guzmán-Manzano, Arturo

    2016-01-01

    En el presente trabajo se describe el diseño e implantación de una interfaz de comunicación basada en la detección de gestos del cirujano para cirugía laparoscópica asistida por la mano. Para el desarrollo del sistema de detección de gestos se va a utilizar el dispositivo hardware Leap Motion, el cual permite registrar secuencias de parámetros físicos de la mano, útiles para la identificación de patrones de movimiento. Esta información es el punto de partida para la implementación de un si...

  5. Influence of organic N Sources on N transformation and uptake by lupine plants using 15N technique

    International Nuclear Information System (INIS)

    Abdel-Salam, A.A.; Gadalla, A.M.; Abdel- Aziz, H.A.; Galal, Y.G.M.; EL-degwy, S.M.

    2008-01-01

    A pot experiment was carried out under greenhouse conditions to evaluate the comparative efficiency and transformation of nitrogen applied either as mineral or organic forms. The obtained data showed that shoot dry weight was enhanced by compost and its mixture with leucaena. When organic sources were combined with 15 N, the leucaena.compost mixture (LC p ) gave the highest yield, and the other two were not significantly different from each other. Reinforcing the organic N with mineral N caused an average greater N.uptake over the non reinforced treatment. Similar trend was noticed with root system. Nitrogen uptake by roots was increased according to the order of LC > L > C. N derived from fertilizer (% Ndff) by lupine shoots was significantly affected by fertilizer addition either alone or reinforced with organic plant residues. Both, the portions (%) or absolute values (mg pot -1 ) of Ndff were increased by adding the organic residues. The highest value of Ndfs was recorded with application of leucaena followed by compost, then Leucaena + compost. Portion Ndfa reflected an effective response of lupines plants to Rhizobium inoculation. Addition of LC mixture combined with 15 N-fertilizer had enhanced the N 2 fixation and increased Ndfa value by about 66.7 % over those recorded with 15 N0 treatment. Organic amendment of leucaena could be an efficient source for N to infertile sandy soils

  6. Auditoría informática basada en riesgos del core bancario de una institución financiera de acuerdo al plan anual 2014 de auditoría interna

    OpenAIRE

    Arciniega Vera, Andrea Johanna; Ludeña González, Verónica Isabel

    2015-01-01

    El presente proyecto de tesis consiste en desarrollar y ejecutar una Auditoría Informática Basada en Riesgos del Core Bancario de una Institución Financiera de la ciudad de Loja, para dar cumplimiento a lo solicitado por organismos de control como la Súper Intendencia de Bancos y Seguros (SBS), para garantizar la confianza depositada por los clientes y la buena imagen institucional. Por tal motivo el departamento de Auditoría Interna de la institución financiera da la oportunidad de participa...

  7. Innovación incremental basada en capacidades dinámicas. Evidencia empírica en las empresas peruanas

    Directory of Open Access Journals (Sweden)

    Alejandro Flores Castro

    2015-09-01

    Full Text Available Los resultados macroeconómicos logrados por el Perú en los últimos años, hacen prever uncrecimiento de la actividad empresarial desde la perspectiva de sus capacidades a fin dealcanzar posiciones de ventaja. Sin embargo, este crecimiento estará basado esencialmenteen procesos de mejora, no vislumbrándose un aporte significativo de parte de las empresasa desarrollar procesos de innovación radical o disruptiva, abocándose preferentemente aprocesos de innovación incremental o de bajo impacto. En la primera parte del documentose aborda el tema de la innovación como factor de ventaja competitiva basado en un modelode capacidades dinámicas, en el contexto de la teoría de recursos y capacidades, analizandolos diferentes modelos de innovación tecnológica. En la segunda parte del trabajo se presentaun modelo de innovación basada en capacidades dinámicas. Y finalmente se presenta lametodología y los resultados del el estudio empírico acerca de los procesos de innovaciónincremental que se dan en las empresas peruanas.

  8. Innovación incremental basada en capacidades dinámicas. Evidencia empírica en las empresas peruanas

    Directory of Open Access Journals (Sweden)

    Alejandro Flores Castro

    2011-06-01

    Full Text Available Los resultados macroeconómicos logrados por el Perú en los últimos años, hacen prever uncrecimiento de la actividad empresarial desde la perspectiva de sus capacidades a fin dealcanzar posiciones de ventaja. Sin embargo, este crecimiento estará basado esencialmenteen procesos de mejora, no vislumbrándose un aporte significativo de parte de las empresasa desarrollar procesos de innovación radical o disruptiva, abocándose preferentemente aprocesos de innovación incremental o de bajo impacto. En la primera parte del documentose aborda el tema de la innovación como factor de ventaja competitiva basado en un modelode capacidades dinámicas, en el contexto de la teoría de recursos y capacidades, analizandolos diferentes modelos de innovación tecnológica. En la segunda parte del trabajo se presentaun modelo de innovación basada en capacidades dinámicas. Y finalmente se presenta lametodología y los resultados del el estudio empírico acerca de los procesos de innovaciónincremental que se dan en las empresas peruanas.

  9. Diseño de un modelo de red domótica libre basada en componentes OpenDomo para aplicación a un pequeño hotel

    OpenAIRE

    López Torres, Valeriano

    2014-01-01

    El objeto de este proyecto es crear un diseño tipo de instalación domótica para un hotel de hasta 100 habitaciones, basada en componentes OpenDomo y fundamentalmente en el controlador ODControl. El modelo de instalación propuesto está orientado principalmente al ahorro energético y, por tanto, al control de los principales elementos que tienen impacto sobre el ahorro, esto es: la iluminación y la climatización del hotel. L'objecte d'aquest projecte és crear un disseny tipus d'instal·lació ...

  10. Redescriptions of Ckll., Ferris and Ckll. and Parrott and their Transfer to Gen. Nov. (Hemiptera: Coccidae, with Descriptions of Two New Species from the Southeastern U.S.A. and Colombia, South America

    Directory of Open Access Journals (Sweden)

    Takumasa Kondo

    2009-01-01

    Full Text Available Three species of Mexican soft scales, Neolecanium leucaenae Cockerell, Toumeyella cerifera Ferris and T. sonorensis Cockerell and Parrott, are redescribed based on the adult females and are transferred to Neotoumeyella gen. nov. as N. leucaenae (Cockerell comb. nov., N. cerifera (Ferris comb. nov. and N. sonorensis (Cockerell and Parrott comb. nov. Two new species, N. caliensis Kondo and Williams sp. nov. from Colombia and N. cephalanthi Kondo and Williams sp. nov. from the U.S.A, are described and illustrated based on the adult female. A key to the genera of New World Myzolecaniinae based on the adult female is provided. We designate lectotypes for N. leucaenae, T. cerifera and T. sonorensis.

  11. La capacitación de ventas basada en inventarios críticos como determinante del apalancamiento operativo en farmacia comunitaria

    Directory of Open Access Journals (Sweden)

    Fernando Alonso Rojas

    2013-04-01

    Full Text Available En el presente documento se cuantifican los efectos de la capacitación de ventas basada en inventarios sobre el apalancamiento operativo de una organización de retail farmacéutico. Se seleccionaron productos y temas de capacitación basándose en inventarios críticos de clasificación ABC, ordenados por márgenes de contribución. Los efectos de la capacitación fueron medidos por la optimización de la magnitud del grado de apalancamiento operativo, y por la correlación lineal de los componentes de resultados y ventas que conforman el parámetro. El caso evidencia que la capacitación de ventas en productos críticos contribuye a optimizar el apalancamiento operativo de un retail de farmacia comunitaria en magnitud y volatilidad de sus constituyentes, lo que puede ser extrapolable a otros sectores del comercio.

  12. La capacitación de ventas basada en inventarios críticos como determinante del apalancamiento operativo en farmacia comunitaria

    Directory of Open Access Journals (Sweden)

    Fernando Alonso Rojas

    2013-01-01

    Full Text Available En el presente documento se cuantifican los efectos de la capacitación de ventas basada en inventarios sobre el apalancamiento operativo de una organización de retail farmacéutico. Se seleccionaron productos y temas de capacitación basándose en inventarios críticos de clasificación ABC, ordenados por márgenes de contribución. Los efectos de la capacitación fueron medidos por la optimización de la magnitud del grado de apalancamiento operativo, y por la correlación lineal de los componentes de resultados y ven- tas que conforman el parámetro. El caso evidencia que la capacitación de ventas en productos críticos contribuye a optimizar el apalancamiento operativo de un retail de farmacia comunitaria en magnitud y volatilidad de sus constituyentes, lo que puede ser extrapolable a otros sectores del comercio.

  13. INTERACTION EFFECT OF TREE LEAF LITTER, MANURE AND

    African Journals Online (AJOL)

    Compound D (8N-l4P-7K) fertilizer (300 kg ha"), and their combinations on maize growth and yield on ... presence of fertilizer. It is hypothesised that the application of Leucaena, manure and miombo litter resulted in immobilisation of nutrients. Leucaena, which is rich in N but low in P, probably .... No lime was applied to the.

  14. La Medicina Basada en la Evidencia: ¿mejoró la medicina que practicamos y enseñamos?

    Directory of Open Access Journals (Sweden)

    Luis Huicho

    2013-07-01

    Full Text Available En los últimos años la práctica y la enseñanza médica han incorporado en forma progresiva y creciente el concepto de medicina basada en la evidencia (MBE. La misma se define como la utilización de la mejor evidencia proveniente de la investigación clínica para la toma de decisiones en el manejo del paciente individual. Esta propuesta de cambio en la manera de practicar y enseñar la medicina clínica es, en parte, consecuencia del vertiginoso avance de la investigación científica, particularmente en las últimas décadas, aunque el costo creciente involucrado en la atención de los pacientes ha jugado también un rol importante en su desarrollo y consolidación. La MBE implica la integración de la preparación y experiencia del médico con la mejor evidencia clínica externa accesible, proveniente de la investigación sistemática, proporcionando una visión más crítica en la toma de decisiones clínicas, para ofrecer atención de calidad óptima al paciente, evitando errores en cada una de las diferentes etapas del proceso de diagnóstico y tratamiento. En ausencia de información recolectada sistemáticamente, no es fácil llegar a una conclusión sobre los efectos de la MBE en la práctica y la enseñanza de la medicina en nuestro medio. Sin duda contamos hoy con mayor evidencia científica, incluyendo aquella relacionada a los problemas de salud infantil, y también se ha producido un avance vertiginoso en la tecnología que nos permite acceder a dicha información en tiempo real, a la cabecera del paciente. Sin embargo, si deseamos de veras lograr una mejor medicina, basada en la ciencia y en el respeto a la salud como un derecho que nos asiste a todos, hay necesidad de romper definitivamente con el paradigma predominante de una medicina jerárquica, poco dada a la discusión y a la justificación de las decisiones clínicas, de aprovechar la mejora sustancial ocurrida en el acceso a la evidencia disponible, y de mostrar mayor

  15. Desarrollo de una Nueva Solución Compacta a la Cinemática de Manipuladores Robóticos basada en Cuaterniones Duales

    Directory of Open Access Journals (Sweden)

    J. Ramírez-Gordillo

    2011-10-01

    Full Text Available Resumen: Este trabajo presenta una nueva solución compacta basada en cuaterniones duales para el desarrollo de la cinemática de manipuladores robóticos. Se plantea el desarrollo de una herramienta en forma completa para poder observar claramente su correlación con el método de las matrices de transformación homogénea derivadas a partir de los parámetros de Denavit-Hartenberg. Se proponen herramientas para simplificar el uso de los cuaterniones duales para la obtención del modelo cinemático de mecanismos de cadena abierta definiendo la regla de la cadena aplicada a estos. Finalmente se ilustra su aplicación a un par de casos de estudio. Palabras clave: Modelo Cinemático, Cuaterniones Duales, Manipuladores Robóticos, Solución Compacta

  16. Avances en el diseño de una herramienta de autor para la creación de actividades educativas basadas en realidad aumentada

    Directory of Open Access Journals (Sweden)

    Moralejo, Lucrecia

    2014-04-01

    Full Text Available En este artículo se presentan los avances logrados en el diseño de una herramienta de autor, llamada AuthorAR, orientada a la creación de actividades educativas basadas en realidad aumentada (RA. AuthorAR permite generar actividades de exploración y de estructuración de frases, que pueden favorecer procesos de adquisición del lenguaje y de entrenamiento de la comunicación, por lo que se hará referencia a las posibilidades que ofrece en este sentido. Se presentan aquí: una descripción de esta herramienta de autor, una revisión de antecedentes en la temática y la propuesta de evolución de este proyecto, con los primeros resultados obtenidos y las conclusiones arribadas.

  17. Replacement of alfalfa hay (Medicago sativa L.) with subabul (Leucaena leucocephala) leaf meal in diets of Najdi goats: effect on digestion activity of rumen microorganisms.

    Science.gov (United States)

    Mohammadabadi, Tahereh; Jolazadeh, Alireza

    2017-08-01

    This study investigated the effect of replacing alfalfa hay by subabul leaf meal (SLM) on digestion, fermentation parameters and rumen bacteria and fungi activity of Najdi goats. Six Najdi goats (150 ± 15 days of age and initial body weight of 35 ± 1.1 kg) were randomly assigned to one of two dietary treatments in a balanced completely randomized design (three goats per treatment) for 56 days. Experimental treatments included alfalfa hay as control group and diet containing SLM (SLM replacing alfalfa hay at 50% level). Bacterial and fungi activity and rumen fermentation parameters of animals fed experimental diets were determined. Dry matter disappearance (DMD) was unaffected by replacing SLM with alfalfa hay for both rumen bacteria and fungi in different incubation times, except for 48 h of incubation in specific culture medium of mixed rumen bacteria, which decreased for SLM group (P > 0.05). NDF disappearance (NDFD) and ADF disappearance (ADFD) after 24 and 48 h of incubation in specific culture medium of mixed rumen bacteria was not affected by experimental diets (P > 0.05). However, 72 h after incubation, NDFD in SLM treatment decreased (P > 0.05). Gas production parameters of rumen bacteria were similar for both experimental diets, but partitioning factor (PF), efficiency microbial biomass production (EMBP), microbial protein production (MP), and organic matter truly digested (OMTD) decreased (p alfalfa hay by SLM had no major effect on rumen microorganisms' activity of Najdi goats, so it may be used as an alternative for alfalfa (at 50% level) in susceptible areas.

  18. Manganese (Mn) stress toward hyperaccumulators plants combination (HPC) using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition on soybean (Glycine max) seedling stage

    Science.gov (United States)

    Darmawan, Tania Sylviana; Zahroh, Tata Taqiyyatuz; Merindasya, Mirza; Masfaridah, Ririn; Hartanti, Dyah Ayu Sri; Arum, Sekar; Nurhatika, Sri; Muhibuddin, Anton; Surtiningsih, Tini; Arifiyanto, Achmad

    2017-06-01

    Heavy metals were a metal bracket which had a specific gravity greater than 5 g / cm3. Manganese was one of them because it has a specific gravity of 7.4 g / cm3. Together with widespread cases of soil contamination caused by heavy metals as well as increased development of the science of breeding ground rapidly, then the alternative rehabilitation techniques were relatively cheap and effective it needs to be developed and even some cases of contaminated management soil using a combination of plants with microorganisms to be more effective. Thus it was necessary to develop research on plants that were able to accumulate heavy metals and other toxic materials, such as Mn so that the land becomes safe for health and the environment. Based on above reason this research aimed to see the influence of hyperaccumulators combination of plants using Jatropha curcas and lamtoro gung (L. leucocephala) in mychorrizal addition to stressed by manganese (Mn) on soybean (Glycine max). Observations of growth, chlorophyll content and heavy metals analysis performed on nine treatments (P1-P9) and one control (P0). The results showed a combination of hyperaccumulators under mychorrizal helped overcome the stress of manganese (Mn) in the leaves of soybean (G. max). It gave an influence on the number of leaves and chlorophyll content of soybean (G. max), but no effect performed on the height and the roots of soybean (G. max). The use of plants in small amounts hyperaccumulators (P1;1 jatropha and 1 lamtoro) was sufficient to cope with stress of Mn in the leaves of soybean (G. max).

  19. Fuentes, búsqueda, análisis de información y calidad de la evidencia: Breve introducción a la Medicina basada en la evidencia

    Directory of Open Access Journals (Sweden)

    Rodrigo Pardo T.

    1999-07-01

    La aplicación del método científico en la práctica clínica ha favorecido el desarrollo de la MBE y puede utilizarse en cualquier situación en que exista duda sobre algún aspecto del diagnóstico, pronostico o tratamiento. De esta manera, la práctica clínica deja a un lado y supera la intuición, la experiencia no sistemática y la toma de decisiones basada exclusivamente en razonamientos soportados en mecanismos fisiopatológicos, para reforzar la evaluación y aplicación de los resultados provenientes de la investigación clínica.

  20. Integración del sistema SoloWAN de optimización de tráfico en redes WAN como un servicio dentro de una plataforma IaaS basada en OpenStack

    OpenAIRE

    Vega García, Carlos

    2016-01-01

    El trabajo consiste en la integración del software SoloWAN de optimización de tráfico en redes WAN, desarrollado en el Center for Open Middleware (COM) de la UPM, como un servicio dentro de una plataforma IaaS basada en OpenStack. Para alcanzar este propósito, se ha llevado a cabo un proceso de desarrollo partiendo del estudio de la plataforma OpenStack, analizando sus características, entendiendo los nodos que de los que está compuesta, así como los diferentes servicios que ofrece. S...

  1. Terapias celulares basadas en el uso de células madre

    Directory of Open Access Journals (Sweden)

    José E. Cardier

    2013-12-01

    Full Text Available Las células madres (CM son las unidades naturales a partir de los cuales pueden diferenciarse todos los tipos de células del organismo. El desarrollo de técnicas para el aislamiento, cultivo, expansión y diferenciación de CM no solo ha permitido avanzar en el conocimiento de la biología de estas células, sino también evaluar su potencial uso en medicina regenerativa. Experimentalmente se ha demostrado que procesos como vasculogénesis, miogénesis, hematopoyesis y neurogénesis pueden generarse a partir de CM. Sin embargo, no existen evidencias claras, publicadas en revistas biomédicas de alto impacto, que demuestren la efectividad clínica del uso de CM para regeneración de órganos en humanos. El trasplante de médula ósea constituye la única terapia basada en CM que ha demostrado su efectividad clínica en pacientes. En esta presentación, nosotros discutiremos acerca de la biología de las CM y de las evidencias actuales sobre el uso de estas células en medicina regenerativa. De acuerdo a la localización de las CM, durante el desarrollo del individuo, estas pueden clasificarse en CM embrionarias (CME y CM adultas, pudiendo quizás agregarse una tercera categoría representada por tejidos fetales, por ejemplo CM de liquido amniotico, de sangre de cordon umbilical, de anexos fetales etc. En la etapa postnatal y adulta del individuo, lasCM pueden ser aisladas a partir de sangre de cordón umbilical (SCU y en la médula ósea (MO. Las CM localizadas en MO están asociadas fundamentalmente con el sistema hematopoyético (generación de células sanguíneas, y se les denomina CM hematopoyéticas (CMH. La facilidad de obtención de las CMH, en la etapa postnatal y adulta del individuo, ha permitido estudiar ampliamente la capacidad de autorenovación, diferenciación y proliferación de estas células. Muchos de los conocimientos generados sobre la biología de las CMH han sido extrapolados a CM localizadas en otros tejidos.

  2. Barbarie cultural extrema y educación basada en la conciencia

    Directory of Open Access Journals (Sweden)

    Agustín de la Herrán Gascón

    2016-06-01

    Full Text Available Se presenta un ensayo en torno a la barbarie extrema practicada por sistemas culturales fanatizados y etnocéntricos. Con este fin se aluden como representativos al Estado Islámico o al nazismo. Se trabaja con la hipótesis de que la inefectividad educativa general contra esta clase de barbarie está relacionada con su deficiente comprensión. Su objetivo es intentar definir algunos fundamentos útiles para una eventual Pedagogía y educación contra la barbarie basadas en la complejidad y la conciencia para, desde ellos, avanzar en el camino de su comprensión y acción educativa. Como es propio de la metodología del ensayo, se expondrán los argumentos del autor apoyados en razones y fuentes precedentes. Al no tratarse de un artículo de revisión y dada la escasez de trabajos científicos sobre educación y barbarie desde la Pedagogía, la selección de fuentes será la suficiente para intentar satisfacer el objetivo del estudio. Las principales aportaciones del artículo son una contribución conceptual de la barbarie desde un punto de vista pedagógico y una propuesta de fundamentos para una educación contra la barbarie extrema realizados desde el «enfoque radical e inclusivo de la formación» (Herrán, 2014a. Las conclusiones del estudio apuntan a un compromiso educativo de todos con este enorme y permanente reto, desde cada ser, conceptuado como parte del fenómeno complejo de la barbarie observada. El trabajo se estructurará en las siguientes partes: introducción, reflexiones sobre la barbarie extrema cultural y su relatividad, modos ordinarios de combatir esta barbarie, la educación como uno de esos modos, algunos fundamentos para una educación contra la barbarie extrema y algunas conclusiones. Se trata de una contribución epistemológica para una eventual Pedagogía de la barbarie, no aún de una propuesta pedagógica aplicada, que se realizará en un trabajo posterior.

  3. Effect of tropical browse leaves supplementation on rumen enzymes of sheep and goats fed Dichanthium annulatum grass-based diets.

    Science.gov (United States)

    Singh, Sultan; Kundu, S S

    2010-08-01

    In a switch-over experiment, eight male animals, four each of sheep and goats of local breeds with mean body weight of 26. 8 +/- 2.0 and 30.0 +/- 2.1 kg, were fed Dichanthium annulatum (DA) grass and four browse species viz. Helictris isora, Securengia virosa, Leucaena leucocephala (LL) and Hardwickia binnata (HB) in four feeding trials to assess their supplementary effect on activity of rumen enzymes. The sheep and goats were offered DA grass with individual browse in 75:25 and 50:50 proportions, respectively, for more than 3 months during each feeding trial, and rumen liquor samples were collected twice at 0 and 4 h post feeding after 60 and 90 days of feeding. Glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT) and glutamate dehydrogenase (GDH) enzymes were determined in the bacteria and protozoa fractions of rumen liquor, while cellulase enzyme activity was measured in mixed rumen liquor. LL and HB had the highest and lowest contents of CP, while fibre contents were lower in early than later browse leaves. Supplementation of browse leaves significantly (P goats on all DA grass-browse-supplemented diets except DA-HB (42.8 units/mg protein), where activity was significantly (P Goat exhibited higher activities of GOT and GPT than sheep in both bacteria and protozoa fraction of rumen liquor, while cellulase activity was similar between the animal species on the grass-browse leaves diets. Results indicate that browse leaves supplementation affect the enzyme activities of sheep and goats rumen, while the goats rumen liquor had higher activities of GOT, GPT and GDH enzyme than sheep.

  4. Biomass production by Coffea canephora Pierre ex Froehner in two productives cycles

    International Nuclear Information System (INIS)

    Bustamante González, Carlos; Rodríguez, Maritza I.; Pérez Díaz, Alberto; Viñals, Rolando; Martín Alonso, Gloria M.; Rivera, Ramón

    2015-01-01

    In areas of the Estación Central de Investigaciones de Café y Cacao located in La Mandarina, Tercer Frente municipality, Santiago de Cuba province, and La Alcarraza, municipality Sagua de Tánamo, Holguín province, the biomass production of Coffea canephora Pierre ex Froehner var. Robusta was assessed from planting until the fourth year in both locations and after pruning until the fourth year in Alcarraza. The coffee trees were planted at 3 x 1,5 m in Cambisol under Samanea saman Jerr shade in the first town and Leucaena leucocephala Lam de Wit in the second. The biomass was separated into: leaves, branches, stems, fruits and roots. From 24 months and one year after pruning, leaflitter was collected monthly. For the study of the root system soil blocks of 25 x 25 x 25 cm were extracted, in an area formed by 1,5 m (distance to the street) and 0,75 m (between plants), centered relative to the coffee plant and up to a meter deep. The extracted soil represented ¼ of the volume occupied by the plant. The dry mass of each organ was determined. Dry matter production reached values of 25 t dry mass ha-1 regardless of the stage of the plantation. Until the fourth year the root system dominated the biomass, followed by the leaves and then the stems. The participation of the fruits in the biomass increased in the crop stage and when concluding the experiment the coffees had dedicated for its formation among the 16-20 % of the total dry mass, independently of the development cycle. (author)

  5. Changes in soil quality indicators under long-term sewage irrigation in a sub-tropical environment

    Science.gov (United States)

    Masto, Reginald Ebhin; Chhonkar, Pramod K.; Singh, Dhyan; Patra, Ashok K.

    2009-01-01

    Though irrigation with sewage water has potential benefits of meeting the water requirements, the sewage irrigation may mess up to harm the soil health. To assess the potential impacts of long-term sewage irrigation on soil health and to identify sensitive soil indicators, soil samples were collected from crop fields that have been irrigated with sewage water for more than 20 years. An adjacent rain-fed Leucaena leucocephala plantation system was used as a reference to compare the impact of sewage irrigation on soil qualities. Soils were analyzed for different physical, chemical, biological and biochemical parameters. Results have shown that use of sewage for irrigation improved the clay content to 18-22.7%, organic carbon to 0.51-0.86% and fertility status of soils. Build up in total N was up to 2,713 kg ha-1, available N (397 kg ha-1), available P (128 kg ha-1), available K (524 kg ha-1) and available S (65.5 kg ha-1) in the surface (0.15 m) soil. Long-term sewage irrigation has also resulted a significant build-up of DTPA extractable Zn (314%), Cu (102%), Fe (715%), Mn (197.2), Cd (203%), Ni (1358%) and Pb (15.2%) when compared with the adjacent rain-fed reference soil. Soils irrigated with sewage exhibited a significant decrease in microbial biomass carbon (-78.2%), soil respiration (-82.3%), phosphatase activity (-59.12%) and dehydrogenase activity (-59.4%). An attempt was also made to identify the sensitive soil indicators under sewage irrigation, where microbial biomass carbon was singled out as the most sensitive indicator.

  6. Demanda de mano de obra y rentabilidad de bancos forrajeros en Esparza, Costa Rica

    Directory of Open Access Journals (Sweden)

    Luz Yaneth Sánchez Sarmiento

    2010-07-01

    Full Text Available En Esparza (Costa Rica se evaluó la viabilidad de invertir en bancos forrajeros (BF como alternativa de suplementación para vacas en sistema doble propósito durante la época seca (125 días. Se usaron como indicadores de rentabilidad el Valor Presente Neto (VPN y la Tasa Interna de Retorno (TIR. Se realizó un análisis de sensibilidad para el incremento del precio de la leche, los concentrados, la gallinaza y la mano de obra. Los modelos se elaboraron comparando los BF de plantas leñosas perennes de corte y acarreo de Cratylia argentea + caña de azúcar (Saccharum officinarum (BFC y de ramoneo Leucaena leucocephala (BFL vs. suplementos comerciales tipos concentrado y gallinaza. En los BFC se requirieron 71.1 jornales/año y el análisis financiero indicó que son rentables al compararlos con la gallinaza (VPN = US$362.2, TIR = 17% y concentrados (VPN = US$1953.9; TIR=39%. En BFL se requirieron 13 jornales/año y fueron igualmente rentables en comparación con gallinaza (VPN = US$1594.7; TIR = 21% y con concentrados (VPN = US$3619.6; TIR=35%. Los modelos fueron sensibles a la producción y cambios de precios en la leche, gallinaza, concentrados y el valor del jornal. Los BF son una buena alternativa para la suplementación de ganado en la época seca y una importante fuente de empleo en la región; sin embargo, los altos costos de la mano de obra contratada pueden limitar la adopción.

  7. Rural Fuel-wood and Poles Research Project in Malawi: a general account

    Energy Technology Data Exchange (ETDEWEB)

    Nkaonja, R S.W.

    1981-01-01

    The Rural Fuel-wood and Poles Research Project was initiated to provide information about afforestation in the dry silvicultural zones. Plantation forestry in Malawi has concentrated on production of timber, poles, and pulpwood. It is estimated that 90% of Malawi's population of 5.5 million live in rural communities, and that the purely domestic wood requirement is 4.05 cubic m per family (of five) annually. In addition, wood is required for agricultural purposes such as tobacco curing. The remaining indigenous forest cannot meet the demand. There is an urgent need for plantations. Rather than simply planting trees, the aim is to make local communities self-sufficient in forest products. In view of the shortage of land, great emphasis is placed on trying species which have many end-uses-- e.g., poles, fuel-wood, mulch, fodder, and shade--and those which can be grown together with farm crops, a concept known as ''agroforestry.'' Over 20 ha of trials were established at locations in the three regions of the country. Acacia albida allows maize and other farm crops to grow under it, provides good shade and fodder, and--as legume--enriches the soil with nitrogen. Eucalypts were included because most produce straight poles for construction, are drought-hardy, and are rated higher than Gmelina arborea in calorific value, durability, and strength. Another tree favored for its multiple uses is Leucaena leucocephala (Hawaiian giant), but it appears that there is considerable mixture of varieties in the seeds. With the exception of one trial at Bwanje, trials have not included farm crops, but the agroforestry element will be a very important consideration in future trials.

  8. Demanda de mano de obra y rentabilidad de bancos forrajeros en Esparza, Costa Rica

    Directory of Open Access Journals (Sweden)

    Sánchez Sarmiento Luz Yaneth

    2010-09-01

    Full Text Available En Esparza (Costa Rica se evaluó la viabilidad de invertir en bancos forrajeros (BF como alternativa de suplementación para vacas en sistema doble propósito durante la época seca (125 días. Se usaron como indicadores de rentabilidad el Valor Presente Neto (VPN y la Tasa Interna de Retorno (TIR. Se realizó un análisis de sensibilidad para el incremento del precio de la leche, los concentrados, la gallinaza y la mano de obra. Los modelos se elaboraron comparando los BF de plantas leñosas perennes de corte y acarreo de Cratylia argentea + caña de azúcar (Saccharum officinarum (BFC y de ramoneo Leucaena leucocephala (BFL vs. suplementos comerciales tipos concentrado y gallinaza. En los BFC se requirieron 71.1 jornales/año y el análisis financiero indicó que son rentables al compararlos con la gallinaza (VPN = US$362.2, TIR = 17% y concentrados (VPN = US$1953.9; TIR=39%. En BFL se requirieron 13 jornales/año y fueron igualmente rentables en comparación con gallinaza (VPN = US$1594.7; TIR = 21% y con concentrados (VPN = US$3619.6; TIR=35%. Los modelos fueron sensibles a la producción y cambios de precios en la leche, gallinaza, concentrados y el valor del jornal. Los BF son una buena alternativa para la suplementación de ganado en la época seca y una importante fuente de empleo en la región; sin embargo, los altos costos de la mano de obra contratada pueden limitar la adopción.

  9. Experimentos con una protección basada en redes de neuronas artificiales

    Directory of Open Access Journals (Sweden)

    Orlys Ernesto Torres Breffe

    2011-10-01

    Full Text Available En este trabajo se muestran los resultados de los experimentos físicos realizados con una protección basada totalmente en Redes de Neuronas Artificiales para un transformador eléctrico a escala de laboratorio. Se demuestra que unas Redes de Neuronas Artificiales entrenadas, con datos provenientes de regímenes simulados matemáticamente, opera correctamente con señales de regímenes provenientes de casos reales, al menos a escala de laboratorio y con niveles reducidos de intensidad. Se describe la instalación experimental, tanto desde el puntode vista de hardware como software utilizando la tecnología de National Instrument. Se entrenan diferentes tipos de Redes Neuronales y todas aprendieron a proteger correctamente. Estos experimentos establecen las pautas para el desarrollo de Relés Electrónicos Inteligentes que no se ajustarían, al menos con datos y valores de difícil comprensión como los actuales relés, sino que se entrenarían una vez mediante la simulación matemática y la experiencia práctica los haría cada vez mejores. In this work is shown the results of the physical experiments done with a protection totally based in Artificial Neural Networks for an electric transformer of the laboratory scale. Its demonstrated that some Artificial Neural Networks trained with data coming from a mathematically simulated regimens, it operates correctly with signals coming fromreal cases, at least to laboratory scale and with reduced levels of intensity. The experimental installation is described, so much from the hardware and software point of view, using the technology of National Instrument. Different types of Artificial Neural Nets are trained and all learned how to protect correctly. These experiments establish the rules forthe development of Intelligent Electronic Relays that would not be adjusted, at least with complex data and values like the current relays, they will be trained once from the mathematically simulation and the

  10. Nutritive value and nutrient digestibility of ensiled mango by-products

    Directory of Open Access Journals (Sweden)

    Sompong Sruamsiri

    2009-10-01

    Full Text Available Mango canning by-products (seed and peel together with ensiled mango peel were subjected to analysis of dry matter (DM, ash, crude protein (CP, crude fibre (CF, ether extract (EE, nitrogen-free extract (NFE, gross energy (GE, neutral detergent fibre (NDF and acid detergent fibre (ADF. In vitro digestibility of DM (IVDMD, ADF (IVADFD and NDF (IVNDFD was determined after digesting the by-products in buffered rumen fluid for 24 or 48 h in an incubator. CP content in peel, seed and peel silage is 4.68, 4.19 and 5.27% respectively. As expected, mango seed has a higher fibre content than mango peel and peel silage as indicated by NDF (53.01 vs 25.87 and 27.56% respectively and ADF (31.02 vs 19.14 and 17.68% respectively. However, mango seed also has greater GE than mango peel and peel silage (4,070 vs 3,827 and 3,984 kcal/g DM respectively, probably due partly to its high fat content.Four head of male native cattle were used to determine nutrient digestibility of ensiled mango by-products by randomly allowing them to receive ensiled mango peel with rice straw (EMPR and different levels of Leucaena leaves. Treatments consisted of: 1 ensiled mango peel + rice straw (90:10; 2 ensiled mango peel + rice straw + Leucaena leaves (85:10:5; 3 ensiled mango peel + rice straw + Leucaena leaves (80:10:10; and 4 ensiled mango peel + rice straw + Leucaena leaves (75:10:15. Addition of Leucaena leaves to silage increased apparent digestibility of DM (53.84, 55.43, 59.04 and 58.69% for the four formulations above respectively, probably because of increasing amounts of CP from Leucaena leaves, resulting in greater digestibility of NDF (39.11, 44.47, 47.12 and 43.32% for the four formulations above respectively. Total digestible nutrients (TDN and digestible energy (DE showed the same trends as apparent digestibility of DM.

  11. Menores Expuestos a Violencia contra la Pareja: Notas para una Práctica Clínica Basada en la Evidencia

    Directory of Open Access Journals (Sweden)

    Beatriz Atenciano Jiménez

    2009-01-01

    Full Text Available Se ha estimado en 188.000 la cifra de niñas y niños expuestos a violencia contra la pareja en España. Las investigaciones indican que esta población presenta a corto y largo plazo dificultades emocionales y conductuales, y síntomas de trauma, asociados a los malos tratos contra sus madres, ejercidos durante la relación de pareja y tras la finalización de la misma. Además, un porcentaje elevado de estos menores sufren también maltrato físico, psicológico y sexual. Se presentan las principales conclusiones, basadas en la investigación científica en lengua inglesa, acerca de las consecuencias de la exposición en los menores, de los maltratadores como padres, y de las mujeres maltratadas como madres. A partir de la evidencia existente sobre esta población, se plantea un marco para la intervención clínica, y se discute su estatus de víctimas secundarias/indirectas, la necesidad de estadísticas e intervenciones.

  12. Herramienta de Análisis y Diseño de Sistemas de Control Basada en Hojas de Cálculo Excel

    Directory of Open Access Journals (Sweden)

    Nourdine Aliane

    2009-10-01

    Full Text Available Resumen: Este artículo presenta una herramienta para el análisis y diseño de sistemas de control basada en hojas de cálculo Excel. Esta herramienta es un conjunto de subrutinas y funciones desarrolladas con el lenguaje VBA. En la actualidad, esta herramienta se limita al manejo de sistemas lineales representados mediante la función de transferencia. El usuario puede especificar modelos, obtener sus respuestas transitorias y en frecuencia, simular un sistema realimentado a través de un controlador, o ajustar los parámetros de un controlador de forma interactiva. Además, la herramienta permite al usuario mantener varias simulaciones en una misma hoja de cálculo, y su carácter interactivo hace posible observar el efecto de varios parámetros sobre el comportamiento de los sistemas de forma inmediata. Para ilustrar el alcance y algunas características de esta herramienta, se han incluido varios ejemplos. Palabras clave: Control, Sistemas lineales, Simulación, Hojas de Calculo

  13. ESTRATEGIAS DIDÁCTICAS BASADAS EN EL ENFOQUE POR COMPETENCIAS EMPLEADAS POR LOS DOCENTES EN LA ENSEÑANZA DE INGENIERÍA CIVIL

    Directory of Open Access Journals (Sweden)

    Días Z., E.

    2015-06-01

    Full Text Available El enfoque basado en competencias durante al acto didáctico, conlleva a tomar en consideración la labor del docente en relación a la planificación de las estrategias que contribuyan al desarrollo educativo. En este sentido, el presente estudio se desarrolló bajo el paradigma cuantitativo y su propósito consistió en determinar si los profesores del programa de ingeniería civil de la Universidad Centroccidental Lisandro Alvarado, reflejaban en sus planificaciones didácticas, estrategias basadas en el enfoque por competencias a fin de ajustar cada programa de las asignaturas bajo el perfil recomendado por la Comisión Central de Currículo. Para recabar esta información se utilizó como instrumento un cuestionario constituido por 23 ítems, aplicado a una muestra de 45 profesores, quienes representaron el 33% de la población objeto de estudio. En los resultados de este estudio se evidencia que los docentes a pesar de haber recibido orientaciones para el rediseño de los programas de las asignaturas que gestionan bajo el enfoque por competencias, presentan deficiencias en el uso de estrategias didácticas basadas en dicho enfoque, que garanticen la formación de un profesional integral, con sensibilidad social y ambiental, tal como se estipula en el nuevo diseño curricular impulsado por la institución. The competency-based approach during teaching, leads to consider the work of teachers in relation to planning strategies that contribute to educational development. In this sense, the present study was developed under the quantitative paradigm and its purpose was to determine whether program faculty of civil engineering at Lisandro Alvarado University, reflected in their teaching plans, strategies based on competence approach to adjust each program subjects to the recommended profile by the Central Commission for Curriculum. To collect this information a questionnaire consisting of 23 items, was applied to a sample of 45 teachers, who

  14. Retos y posibilidades de la enseñanza del inglés basada en contenidos en la educacion superior: visión de los docentes en una experiencia en Colombia

    OpenAIRE

    González Moncada, Adriana; Sierra Ospina, Nelly

    2008-01-01

    La enseñanza del inglés en la educación universitaria es una prioridad para la mayoría de los países. Las nuevas metodologías apuntan a la enseñanza del inglés para fines académicos y basadas en contenidos como formas de que el aprendizaje de la lengua no se separe del de competencias académicas. Este estudio de caso desarrollado en varios contextos muestra cómo dos grupos de docentes universitarios de idiomas y de otras ramas del conocimiento trabajaron de forma colaborativa para enseñar cur...

  15. Aplicación móvil basada en el contexto para promover el aprendizaje del idioma inglés

    Directory of Open Access Journals (Sweden)

    Osiris Montero Ríos

    2017-11-01

    Full Text Available La telefonía móvil que en un principio se comercializó como dispositivos de comunicación y entretenimiento, en la actualidad es empleada en sectores tan diversos como la educación. Dentro de los métodos de apoyo al proceso de aprendizaje destacan las aplicaciones móviles y en especial las relacionadas con los idiomas. En su mayoría, estas aplicaciones emplean estrategias de enseñanza universal que sugieren situaciones ajenas al entorno sociocultural del usuario, lo cual podría impactar en su aprendizaje. En este artículo se muestra el desarrollo de una aplicación Android para promover el aprendizaje del idioma inglés basada en información provista por el usuario que le resulta de su interés. Se presenta el diseño del contenido educativo y de la aplicación móvil que permiten al usuario generar su propio material didáctico en base a sus intereses. Como caso de estudio se considera la evaluación de la aplicación para el área de las ciencias computacionales.

  16. Una estrategia basada en modelos para el diagnóstico de fallas en el estator del motor de inducción

    Directory of Open Access Journals (Sweden)

    Cristian H. De Angelo

    2007-07-01

    Full Text Available Resumen: Se presenta una estrategia para el diagnóstico de fallas en el estator de los motores de inducción mediante la información contenida en las tensiones y corrientes de alimentación. La estrategia propuesta está basada en la generación de un vector de residuos específicos por medio de un observador de estados, el cual permite detectar la fase dañada y cuantificar el ńumero de espiras en cortocircuito. La estrategia de diagnóstico es muy poco sensible a los cambios de carga o perturbaciones de la red de alimentación tales como armónicos o desbalances. Palabras clave: Diagnóstico de fallas, fallas en el estator, motor de inducción

  17. ENTORNO DE PRUEBAS PARA SERVICIOS INTERACTIVOS DE TELEVISIÓN MÓVIL BASADA EN EL ESTÁNDAR DVB-H

    Directory of Open Access Journals (Sweden)

    GABRIEL CHANCHÍ GOLONDRINO

    2012-06-01

    Full Text Available La televisión móvil basada en el estándar DVB-H no ha tenido una aceptación semejante a la de la televisión convencional, lo anterior debido a dificultades propias del estándar y a características de despliegue del servicio. Las problemáticas de la televisión móvil se resumen en: necesidad de una red bidireccional alterna o canal de retorno para el consumo de servicios, el tiempo de salto de un canal a otro, elbajo tiempo promedio de uso diario de la televisión móvil, los pocos dispositivos que soportan el estándar y la no existencia de un middleware para el desarrollo de aplicaciones interactivas de televisión móvil. Elpresente artículo plantea un entorno de despliegue y pruebas para servicios interactivos de televisión móvil, que busca responder a los anteriores problemas.El entorno propuesto tiene en cuenta aspectos como la convergencia de servicios en redes WLAN, el uso falcsonomías para recomendación de contenidos y la red celular como canal de retorno o canal de consumode servicios

  18. El aprendizaje de las plantas como seres vivos: una metodología basada en el dibujo infantil

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    Xabier Villanueva

    2017-06-01

    Full Text Available Estudios previos han investigado el desarrollo del concepto de ser vivo en edades tempranas desde diferentes perspectivas metodológicas. Sin embargo, estos enfoques ponen excesivo énfasis en la comunicación verbal a la hora de llevar a cabo las tareas lo que puede llevar a limitaciones a la hora de medir este concepto biológico. Por ello, se presenta una aproximación desde una metodología no verbal basada en las producciones pictóricas del alumnado. La presente investigación tiene como objetivo analizar la relación entre la noción de ser vivo y el dibujo infantil en una muestra de 197 niños y niñas de entre 4 y 8 años de edad. Para ello, se realizan tareas de categorización de imágenes de seres vivos e inertes y la recogida de expresiones gráficas sobre el mundo vegetal. Los resultados de las tareas realizadas apuntan la consideración de que el alumnado con el conocimiento más preciso sobre si las plantas están vivas dibujan más frecuentemente elementos pictóricos relacionados con la vida como el sol, el agua, semillas, las nubes, y tienden a dibujar también más tipos de plantas.

  19. Diseño de estrategias digitales basadas en la Web 3.0 para difundir los lugares turísticos del Cantón Penipe provincia de Chimborazo. año 2016.

    OpenAIRE

    Vergara Zurita, Heidy Elizabeth

    2016-01-01

    El presente proyecto tuvo como objetivo diseñar estrategias digitales basadas en la Web 3.0 para la difusión de los lugares turísticos del Cantón Penipe, Provincia de Chimborazo, en función que las tendencias actuales se están trasladando a los mercados virtuales. Para lo cual se realizó una investigación trasversal de tipo no experimental observándose las reacciones del público objetivo ante las estrategias digitales de la Web 3.0, un diagnóstico determinándose la problemática del sector a p...

  20. Epistemografía y didáctica. La enseñanza basada en la investigación a través de artículos científicos

    OpenAIRE

    Gutiérrez Avendaño, Jairo; Institución Universitaria de Envigado

    2012-01-01

    Los artículos científicos como objeto de estudio constituyen una forma de acercarse a la práctica de los docentes investigadores y, a su vez, permiten identificar las características y el potencial epistémico-didáctico de artículos de investigación, para la enseñanza basada en la investigación, en este caso los publicados por docentes en las revistas de alto nivel A1 y A2 de Antioquia. Asimismo, se encontraron las tendencias discursivas relacionadas con el campo de la pedagogía y la didáctica...

  1. Plantas tóxicas para ruminantes e equídeos da microrregião do Cariri Cearense Plant poisonings in ruminants and horses in Southern Ceará, Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    Cícero Wanderlô Casimiro Bezerra

    2012-06-01

    Full Text Available Em um levantamento, feito no período de agosto de 2009 a novembro de 2010, sobre as plantas tóxicas para ruminantes e equídeos no Cariri Cearense (municípios de Juazeiro do Norte, Crato, Barbalha e Missão Velha, foram realizadas 21 entrevistas a produtores, médicos veterinários, engenheiros agrônomos e técnicos agropecuários. As intoxicações por Ipomoea asarifolia, mencionada por 38% e 19% dos entrevistados como tóxicas para bovinos e ovinos, respectivamente, e Enterolobium contotisiliquum, mencionada como tóxica para bovinos (47,6% dos entrevistados e ovinos (4,7% foram as mais frequentemente mencionadas. Ocorrem, também, na região, intoxicações por Mascagnia rigida (mencionada por 38% do entrevistados, Anadenanthera colubrina var. cebil (=A. macrocarpa (14%, Ricinus communis (14%, Thiloa glaucocarpa (9% e Sorghum halepense (4% em bovinos, Brachiaria decumbens em ovinos e bovinos (38%, Mimosa tenuiflora em ovinos, caprinos e bovinos (38%, Manihot spp. em bovinos e caprinos (28% e Leucaena leucocephala em ovinos e equinos (4%. Seis plantas não conhecidas anteriormente como tóxicas, mas mencionadas como causa de intoxicação pelos entrevistados, foram testadas experimentalmente em diferentes doses. Somente Casearia commersoniana resultou tóxica para caprinos na dose diária de 20g kg-1 de peso vivo por 2-4 dias. Os sinais clínicos, semelhantes aos descritos pelos produtores, foram de relutância em movimentar-se, meteorismo discreto, polaquiúria, vocalização, ingurgitamento da jugular e pulso jugular, andar cambaleante, quedas, espasticidade dos membros, movimentos de pedalagem, opistótono, taquicardia e taquipneia, seguidos de bradicardia e bradipnéia. A morte ocorreu 6 e 19 horas após o início dos sinais. Não foram encontradas lesões macroscópicas nem histológicas de significação. Conclui-se que as intoxicações por plantas são uma causa importante de perdas econômicas para a região, cuja população

  2. Avaliação de fontes de urease na amonização de fenos de Brachiaria brizantha com dois teores de umidade Evaluation of urease sources in the ammoniation of Brachiaria brizantha hays with two moisture levels

    Directory of Open Access Journals (Sweden)

    Liandra Maria Abaker Bertipaglia

    2005-04-01

    Full Text Available O efeito da amonização com uréia (5,0% matéria seca do feno de Brachiaria brizantha, com dois teores de umidade (15 ou 30% de umidade, associado a três fontes de urease (feno de capim Brachiaria decumbens, capim-elefante [Pennisetum purpureum] e leucena [Leucaena leucocephala], foi avaliado. Foram determinados os teores de proteína bruta (PB, fração solúvel (A, frações de proteína verdadeira solúvel e insolúvel em borato fosfato (B1 e B2, fração de proteína potencialmente degradável (B3 e fração da proteína insolúvel em detergente ácido (C. Avaliaram-se os teores de fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, celulose (CEL, hemicelulose (HEM e lignina (LIG e digestibilidade in vitro da matéria seca (DIVMS. O delineamento experimental foi o de blocos inteiramente casualizados, com 10 tratamentos (dois controles, 15 e 30% umidade, sem uréia e sem urease; dois controles, 15 e 30% umidade, com uréia e sem urease; seis combinações de fontes de urease e conteúdo de umidade e três repetições. A amonização dos fenos com diferentes conteúdos de umidade, associados a fontes de urease, aumentou os teores de PB e da fração A, mas não afetou B1 e B2. Contudo, as frações B3 e C diminuíram em reposta à amonização. A aplicação de uréia nos fenos de 30% de umidade, associados ou não a fontes de urease, diminuiu os teores de FDN. A adição de fontes de urease não alterou os teores dos constituintes da parede celular, quando comparada aos tratamentos amonizados com uréia. Os tratamentos aplicados não proporcionaram efeitos consistentes sobre os teores de FDA e de CEL dos fenos e não afetaram os teores de LIG. A aplicação de uréia associada a 15 ou 30% de umidade foi favorável para aumentar o nitrogênio solúvel do feno de Brachiaria brizantha e diminuir o nitrogênio indisponível para o ruminante.The urea ammoniation (5.0% dry matter effects in Brachiaria brizanta hay baled with two

  3. Fabricación y estudio de las propiedades físicas de nanopartículas de aleación, núcleo@corteza y núcleo@corteza@corteza basadas en Co, Au y Ag

    OpenAIRE

    Llamosa Pérez, Daniel

    2014-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física Aplicada. Fecha de lectura: 18-11-2014 En este trabajo de tesis se presenta un estudio sobre la fabricación y caracterización de nanopartículas (NPs) basadas en Co, Au y Ag. Todas las nanopartículas fueron fabricadas utilizando la técnica de agregación de gas pero en diferentes dispositivos experimentales. En la primera parte se presentan NPs CoAu producidas por...

  4. El reconocimiento del estatuto de refugiado por motivo de violencia basada en el género durante situaciones de conflicto armado

    Directory of Open Access Journals (Sweden)

    Sabrina Paula Vecchioni

    2017-07-01

    Full Text Available La definición clásica de refugiado ha sido puesta a prueba por los eventos de un mundo en constante cambio frente a la necesidad de protección internacional cuando aquella proporcionada por el Estado de nacionalidad o de residencia habitual no resulta efectiva. Los desplazamientos masivos de población originados por conflictos armados, pusieron a prueba el estatuto de refugiado a partir de interpretaciones regionales que amplían los supuestos de protección internacional. Sumado a ello, encontramos el desarrollo sobre violencia basada en el género de las teorías feministas en dichos contextos. En este trabajo analizamos la complementariedad del Derecho Internacional de los Derechos Humanos y el Derecho Internacional Humanitario a la luz del Derecho Internacional de los Refugiados, estableciendo la plena e irrestricta vigencia de la protección internacional en los casos de mujeres forzadas a desplazarse de sus países de origen, como consecuencia de una situación de conflicto armado.

  5. ¿SE PUEDE MEDIR LA NEGOCIACIÓN INFORMADA?: UNA REVISIÓN DE LA METODOLOGÍA BASADA EN LAS COVARIANZAS DE LAS SERIES DE PRECIOS

    Directory of Open Access Journals (Sweden)

    García Martín, C.J.

    2009-01-01

    Full Text Available El desarrollo en los modelos teóricos de microestructura ha motivado la aparición de un grupo de trabajos encaminado al estudio empírico de los costes de transacción y sus componentes dada la importancia que han tenido los mismos en el estudio del funcionamiento de los mercados y la comparación entre éstos así como sus numerosas aplicaciones en campos afines (finanzas corporativas, eficiencia de los mercados, etc.. Por otra parte, la contrastación empírica de los distintos modelos establecidos muestra resultados claramente dispares. Por ello, el objetivo de nuestro trabajo es analizar con detalle y en conjunto dichos modelos centrándonos en un grupo con características muy similares. Concretamente desarrollaremos aquellos modelos cuyas estimaciones están basadas en las autocovarianzas de las series de precios y/o rendimientos.

  6. Formación de Profesores de Ciencias: Una Perspectiva basada en la Historia y Filosofía de la Ciencia

    Directory of Open Access Journals (Sweden)

    Mansoor Niaz

    2012-04-01

    Full Text Available El objetivo de este artículo es de reseñar algunos de los experimentos más importantes de los últimos cien años, dentro de una perspectiva crítica de la historia y filosofía de la ciencia. El análisis de los experimentos muestra que el desarrollo científico es muy complejo e involucra interpretaciones alternativas de los datos experimentales, lo que inevitablemente produce conflictos y controversias entre los científicos. Muchos de estos conflictos requieren la intervención de la comunidad científica para su resolución y a veces tardan largos periodos de tiempo. Una revisión bibliográfica de la enseñanza de la ciencia muestra que la mayoría de las/los profesoras(es de ciencia y textos ignoran estos aspectos del desarrollo científico. Se sugiere que la inclusión de una perspectiva basada en la historia y filosofía de la ciencia puede facilitar una mejor comprensión de la ciencia y asimismo motivar a los estudiantes y los profesores de ciencia, para seguir haciendo la ciencia.

  7. El papel de las variables sociodemográficas en el uso de las aplicaciones basadas en Internet por los Mayores

    Directory of Open Access Journals (Sweden)

    Begoña Peral Peral

    2013-06-01

    Full Text Available La población mundial está envejeciendo progresivamente. Se prevé que en 2050 el número de personas mayores de 60 años alcance los dos mil millones en el mundo. El empleo de las Tecnologías de la Información y Comunicación (TIC puede suponer para la población de mayor edad un impacto significativo en su calidad de vida, contribuyendo a conseguir mayores activos, disminuyendo la marginalización y el aislamiento social. Aunque existen diferencias importantes en el uso que los Mayores hacen de Internet y sus aplicaciones respecto al resto de la población, hay que considerar que este segmento no constituye un grupo homogéneo. Este trabajo busca comprobar si dentro del grupo de los Mayores existen diferencias en la frecuencia de uso de distintas aplicaciones basadas en Internet, en función de la edad, el sexo, el nivel de estudios alcanzados y la actividad laboral desarrollada en el pasado. Los resultados demuestran que existen diferencias significativas en el empleo de algunas aplicaciones en función de las variables sociodemográficas analizadas.

  8. Application of Technology on Improving Beef Cattle Productivity in East Nusa Tenggara

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    Wirdahayati R B

    2010-03-01

    Full Text Available The Province of East Nusa Tenggara (NTT had been one of the major beef cattle suppliers under traditional management system in Indonesia. The beef cattle farming that based on grazing native pasture and the introduction of shrub legumes (Leucaena leucocephala may contribute to around 15 – 50% of the farmers’ household income. In the last few years, supply of beef cattle tended to decline due to the decrease in cattle population in NTT. Some basic improvements in management and feeding toward increasing beef cattle productivities had been carried out in Nusa Tenggara, such as a baseline survey on Cattle Health and Productivity Survey (CHAPS conducted in 1990 – 1992. The objective of the program was to identify the existing beef cattle productivity and health condition throughout Nusa Tenggara. A collaborative research with the Ministry of Research and Technology (Integrated Prime Research had also been carried out and the result showed that early weaning in Bali calves that can be practised as early as 3 – 6 months to prevent calves losses during the dry season. A program of the Assessment on Beef Cattle Base Farming Activities had also been conducted to improve fattening and breeding practices through the improvement in beef cattle management and feeding systems. At the latest development, fattening scheme has been introduced under a partnership approach involving private sectors and cooperatives. This needs to be facilitated by the government to accelerate the program such as access to capital and intensive extension services to build farmers awareness toward profit oriented beef cattle farming. Optimalization of the available potential resources and technology in NTT, will be an opportunity to enhance beef cattle production and gains back the reputation as one of the major producing beef cattle in the past. This will also support the national livestock program nowadays, called Beef Cattle Self Sufficiency Program 2014.

  9. Isolation and Characterization of Alfalfa-Nodulating Rhizobia Present in Acidic Soils of Central Argentina and Uruguay

    Science.gov (United States)

    del Papa, María F.; Balagué, Laura J.; Sowinski, Susana Castro; Wegener, Caren; Segundo, Eduardo; Abarca, Francisco Martínez; Toro, Nicolás; Niehaus, Karsten; Pühler, Alfred; Aguilar, O. Mario; Martínez-Drets, Gloria; Lagares, Antonio

    1999-01-01

    We describe the isolation and characterization of alfalfa-nodulating rhizobia from acid soils of different locations in Central Argentina and Uruguay. A collection of 465 isolates was assembled, and the rhizobia were characterized for acid tolerance. Growth tests revealed the existence of 15 acid-tolerant (AT) isolates which were able to grow at pH 5.0 and formed nodules in alfalfa with a low rate of nitrogen fixation. Analysis of those isolates, including partial sequencing of the genes encoding 16S rRNA and genomic PCR-fingerprinting with MBOREP1 and BOXC1 primers, demonstrated that the new isolates share a genetic background closely related to that of the previously reported Rhizobium sp. Or191 recovered from an acid soil in Oregon (B. D. Eardly, J. P. Young, and R. K. Selander, Appl. Environ. Microbiol. 58:1809–1815, 1992). Growth curves, melanin production, temperature tolerance, and megaplasmid profiles of the AT isolates were all coincident with these characteristics in strain Or191. In addition to the ability of all of these strains to nodulate alfalfa (Medicago sativa) inefficiently, the AT isolates also nodulated the common bean and Leucaena leucocephala, showing an extended host range for nodulation of legumes. In alfalfa, the time course of nodule formation by the AT isolate LPU 83 showed a continued nodulation restricted to the emerging secondary roots, which was probably related to the low rate of nitrogen fixation by the largely ineffective nodules. Results demonstrate the complexity of the rhizobial populations present in the acidic soils represented by a main group of N2-fixing rhizobia and a second group of ineffective and less-predominant isolates related to the AT strain Or191. PMID:10103231

  10. Production of high quality adsorbent charcoal from Phil. Wood II. Granulated activated carbon

    International Nuclear Information System (INIS)

    Arida, V.P.; Atienza, O.G.; Quilao, T.A.; Caballero, A.R.; Laxamana, J.S.; Pugal, D.L.; Guce, C.P.

    1992-01-01

    Two Philippine wood species out of twelve earlier studied in part I namely ''ipil-ipil'' Leucaena leucocephala (Lann) de Wit and coconut coir dust were selected for the production of good quality granulated activated carbon. Fluidization method was used in the study. The conditions for the granulation of the carbonized chars using molasses were established. An optimum ratio of 1:0.5 and 1:0.8 (char:binder) was used in the granulation process for ''ipil-ipil'' and coir dust, respectively. Carbonization was done at gradually increasing temperature of 3 0 C/min at 600 0 C. Carbonized granules with particle sizes ranging from 0.5-2.0 mm were used for the activation study. The produced granules were activated in an external heat type stainless steel reactor as mentioned in Part I using steam as activating agent. The physical properties and adsorptive capacity of the activated granular products obtained at varying activation were determined and correlated. Methylene blue adsorption and internal surface area obtained at varying conditions were determined and correlated. Maximum values obtained for methylene blue adsorption and internal surface area are 290 mg/g AC and 1,200m 2 /g AC at 900 0 C, respectively for ''ipil-ipil'' and 390 mg/g AC and 1,000m 2 g AC at 850 0 C respectively for coir dust. Gas adsorption tests done using benzene acetone and carbon tetrachloride for both ''ipil-ipil'' and coir dust activated granular char products showed that both exhibited maximum absorbability at 900 0 C. Results of the study have shown that good quality granulated activated carbon can be produced from ''ipil-ipil'' and coir dust which find suitable applications in various adsorption processes such as organic solvent adsorption, gas adsorption, water purification, oil and sugar refining, among others. (auth.). 3 refs.; 4 tabs.; 14 figs

  11. Prácticas de conservación de suelos en sistemas de cultivo maíz-frijol en Cuba

    Directory of Open Access Journals (Sweden)

    Alfonso Claro A.

    2000-01-01

    Full Text Available Se realizaron dos ensayos en segmentos de microcuencas en condiciones de producción de la Provincia de Pinar del Río: uno en Campo Hermoso y el otro en La Comunidad La Leña, Cuba. En ambas localidades se rotó el frijol variedad Bat 304 y Tomeguin 93, seguidos de maíz asociado con Mucuna deeringianum y se establecieron bordes de desagüe protegidos con barreras vivas de Leucaena leucocephala y Gliricidia sepium. Las pérdidas de suelos se estimaron en piscinas de sedimentación y limnígrafos Valday en Campo Hermoso y en el caso de La Leña sólo se determinaron las variaciones de la pendiente y el espesor máximo de sedimentos (EMS al final de cada ciclo. El suelo fue un Ferralítico Cuarcítico (Ultisol, la fertilización se realizó de acuerdo a sus reservas, la preparación y labores culturales con tracción animal. Los resultados al cabo de cinco años mostraron una reducción en las pérdidas de suelos por debajo del umbral permisible (5 t/ha, aumento de la altura de las terrazas debido a los sedimentos acumulados, mayor disponibilidad de agua en la sección receptora, mayor cobertura en el período lluvioso, disminución del efecto erosivo de la lluvia, reciclaje de nutrimentos a través de los abonos verdes e incremento de los rendimientos respecto a las áreas donde no se realizaron prácticas de manejo. Se concluyó que el manejo integrado de los diferentes factores en laderas con pendientes mayores de 5%, es necesario para la conservación de suelos y agua

  12. Methane Production of Different Forages in Ruminal Fermentation

    Directory of Open Access Journals (Sweden)

    S. J. Meale

    2012-01-01

    Full Text Available An in vitro rumen batch culture study was completed to compare effects of common grasses, leguminous shrubs and non-leguminous shrubs used for livestock grazing in Australia and Ghana on CH4 production and fermentation characteristics. Grass species included Andropodon gayanus, Brachiaria ruziziensis and Pennisetum purpureum. Leguminous shrub species included Cajanus cajan, Cratylia argentea, Gliricidia sepium, Leucaena leucocephala and Stylosanthes guianensis and non-leguminous shrub species included Annona senegalensis, Moringa oleifera, Securinega virosa and Vitellaria paradoxa. Leaves were harvested, dried at 55°C and ground through a 1 mm screen. Serum bottles containing 500 mg of forage, modified McDougall’s buffer and rumen fluid were incubated under anaerobic conditions at 39°C for 24 h. Samples of each forage type were removed after 0, 2, 6, 12 and 24 h of incubation for determination of cumulative gas production. Methane production, ammonia concentration and proportions of VFA were measured at 24 h. Concentration of aNDF (g/kg DM ranged from 671 to 713 (grasses, 377 to 590 (leguminous shrubs and 288 to 517 (non-leguminous shrubs. After 24 h of in vitro incubation, cumulative gas, CH4 production, ammonia concentration, proportion of propionate in VFA and IVDMD differed (p<0.05 within each forage type. B. ruziziensis and G. sepium produced the highest cumulative gas, IVDMD, total VFA, proportion of propionate in VFA and the lowest A:P ratios within their forage types. Consequently, these two species produced moderate CH4 emissions without compromising digestion. Grazing of these two species may be a strategy to reduce CH4 emissions however further assessment in in vivo trials and at different stages of maturity is recommended.

  13. Effects of Calf Rearing Package Introduced to Smallholder Dairy Farms in Bahati Division, Nakuru District, Kenya

    International Nuclear Information System (INIS)

    Lanyasunya, T.P.; Wekesa, F.W.; Sinkeet, S.N.O.; Jong, R.; Udo, H.; Mukisira, E.A.

    1999-01-01

    A Calf rearing package of Individual (mobile) pens , milk and fodder feeding was introduced on smallholder farms of Bahati Division, Nakuru District, Kenya. The study investigated the effects of changes in Calf rearing practices on calf performance and the responses of the production systems to the investigations. 46 farmers were selected on the basis of their willingness to participate in the study and were allocated to Control (23 and Test (23). both types of farmers were trained but only test farms received building materials and forage seeds. Socio-economic and calf performance data were collected. Calves were supplemented with sweet potato vines (SPV) + Green leaf desmodium (DES) and/or fodder shrubs (FOD) Leucaena leucocephala and Sesbania sesban. Analysis of variance (ANOVA) models and Chi-square test were applied on the data collected. The study revealed that there were variations in off-farm, livestock and crop incomes. The gross Margins (GM) were higher (P < 0.01) for the test than the Control farmers. Calves raised in Test farms Demonstrated higher (P < 0.05) growth rates than those in Control farms (370 versus 307 g/d). Female calves gained (P < 0.05) 57 g/d more than mal calves.Those with assorted farm grown legumes (SPV + FOD) performed better (375 and 417 g/d, respectively) compared to those supplemented with SPV alone or not supplemented (345 and 321 g/d, respectively). Improved calf performance in Test farms suggests that, farm grown forage legumes, could be used as a cheap alternative protein supplement by resource-poor farmers. Calf mortality rates for Control farms (33%) were higher (P < 0.05) than those for Test farms (12.5%). The study concluded that the interventions/measures taken improve the overall performance of calves on-farm

  14. Estimating Apparent Nutrient Digestibility of Diets Containing or Leaf Meals for Growing Rabbits by Two Methods

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    A. M. Safwat

    2015-08-01

    Full Text Available This study aimed to evaluate the nutrient digestibility of growing rabbits fed diets with different levels of either Leucaena leucocephala (LLM or Moringa oleifera (MOLM leaf meals and also to compare total collection and TiO2 marker methods for estimating digestibility. A total of 30 California growing rabbits (1.81±0.19 kg live weight on average were randomly distributed into five experimental groups of six rabbits each and were housed in individual cages. The groups were control, 30% LLM, 40% LLM, 30% MOLM, and 40% MOLM. All groups received pelleted diets for two weeks; diets also contained 4 g/kg titanium dioxide as dietary marker. Daily feed intake was recorded during the whole experimental period and total feces were collected daily and weighed individually during four days. The results showed that there were no difference (p>0.05 in feed, dry matter (DM, organic matter (OM, crude protein (CP, digestible energy, and crude fiber (CF intake between the control group and the other experimental groups. The apparent digestibility values of DM, OM, CP, CF, acid detergent fiber, and gross energy were the highest for control group (p = 0.001, meanwhile MOLM diets had generally higher nutrient digestibility coefficients than LLM diets. Increasing the inclusion level of leaf meal in the diet from 30% to 40% improved the digestibility of CF from 45.02% to 51.69% for LLM and from 48.11% to 55.89% for MOLM. Similar results for apparent nutrient digestibility coefficients were obtained when either total collection or indigestible marker method was used. In conclusion, the digestibility of MOLM containing diets were better than LLM diets, furthermore TiO2 as an external marker could be used as a simple, practical and reliable method to estimate nutrients digestibility in rabbit diets.

  15. Qualitative and anatomical characteristics of tree-shrub legumes in the Forest Zone in Pernambuco state, Brazil

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    Mônica Alixandrina da Silva

    2012-12-01

    Full Text Available The objective of this study was to characterize the nutritional value of forage legumes Mimosa caesalpiniifolia (Benth., Bauhinia cheilantha (Bong. and Leucaena leucocephala (Lan. and evaluate the anatomy of plants incubated and not incubated in the rumen. The experiment was conducted from September 2007 to November 2008. The experimental plot consisted of three useful plants, totaling three plots per block, and four repetitions. Plants were cut at 1 m height at intervals of 70 days; samples of leaf plus stem with a diameter smaller than 4 mm were collected for determination of dry matter, crude protein, neutral detergent fiber, acid detergent fiber, insoluble protein bound to acid detergent fiber and in vitro dry matter digestibility. The anatomical characterization occurred through the analysis of the proportion of plant tissue nonincubated and incubated in the rumen for a period of 48 hours. The legumes had high crude protein, with an average of 26.1% to Leucena, 22.4% to Sabiá and 18.5% to Mororó, and low levels of in vitro digestibility of dry matter, with an average of 47.3% to Leucena, 42.8% to Mororó and 37.2% to Sabiá. In the leaf blade of Sabiá plants, much lignified tissues that differed from plants of Leucena and Mororó were observed. The degradation process was more visible in the leaves of the Leucena, Sabiá and Mororó plants. The degradation was more pronounced in the spongy parenchyma, leaving the incubated material intact. The average proportion of the epidermis in the incubated and not incubated leaves was 15.8 and 16.4% in Leucena, 16.8 and 19.2% in Mororó and 27.2 and 25.5% in Sabiá, respectively. There are differences in the digestion and nutritional value of leaf tissues of the evaluated legumes.

  16. Genotypic Characterization of Bradyrhizobium Strains Nodulating Endemic Woody Legumes of the Canary Islands by PCR-Restriction Fragment Length Polymorphism Analysis of Genes Encoding 16S rRNA (16S rDNA) and 16S-23S rDNA Intergenic Spacers, Repetitive Extragenic Palindromic PCR Genomic Fingerprinting, and Partial 16S rDNA Sequencing

    Science.gov (United States)

    Vinuesa, Pablo; Rademaker, Jan L. W.; de Bruijn, Frans J.; Werner, Dietrich

    1998-01-01

    We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphisms (PCR-RFLPs), 16S-23S rDNA intergenic spacer (IGS) RFLPs, and repetitive extragenic palindromic PCR (rep-PCR) genomic fingerprints with BOX, ERIC, and REP primers. Cluster analysis of 16S rDNA restriction patterns with four tetrameric endonucleases grouped the Canarian isolates with the two reference strains, Bradyrhizobium japonicum USDA 110spc4 and Bradyrhizobium sp. strain (Centrosema) CIAT 3101, resolving three genotypes within these bradyrhizobia. In the analysis of IGS RFLPs with three enzymes, six groups were found, whereas rep-PCR fingerprinting revealed an even greater genotypic diversity, with only two of the Canarian strains having similar fingerprints. Furthermore, we show that IGS RFLPs and even very dissimilar rep-PCR fingerprints can be clustered into phylogenetically sound groupings by combining them with 16S rDNA RFLPs in computer-assisted cluster analysis of electrophoretic patterns. The DNA sequence analysis of a highly variable 264-bp segment of the 16S rRNA genes of these strains was found to be consistent with the fingerprint-based classification. Three different DNA sequences were obtained, one of which was not previously described, and all belonged to the B. japonicum/Rhodopseudomonas rDNA cluster. Nodulation assays revealed that none of the Canarian isolates nodulated Glycine max or Leucaena leucocephala, but all nodulated Acacia pendula, C. proliferus, Macroptilium atropurpureum, and Vigna unguiculata. PMID:9603820

  17. Influencia del probiótico Sorbifauna en la producción y calidad de la leche de vacas mestizas en pastoreo

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    Tania Sánchez

    Full Text Available El objetivo de la investigación fue evaluar la inclusión del probiótico Sorbifauna en la producción y calidad de la leche de vacas Holstein × Cebú que pastoreaban en una asociación de Leucaena leucocephala cv. Cunningham y Megathyrsus maximus cv. Likoni; el estudio se realizó en el periodo mayo-junio de 2013, en la Estación Experimental de Pastos y Forrajes Indio Hatuey. Se utilizaron 12 vacas (clínicamente sanas en un diseño Switch Back, con tres tratamientos: A: pastoreo en la asociación + 60 g de aditivo, B: pastoreo en la asociación + 90 g de aditivo, y C: pastoreo en la asociación + 120 g de aditivo. Se estimó la disponibilidad de pasto y se midió la producción de leche durante el experimento, para lo que se tuvo en cuenta la producción promedio inicial (10,0 ± 2,2 kg, en 84 ± 54 días de lactancia. Además, se determinaron los porcentajes de grasa, proteína, lactosa y sólidos totales. La producción de leche fue de 11,9; 12,1 y 12,2 kg/vaca/día, sin diferencias significativas entre los tratamientos, al igual que para la grasa (3,8; 4,0 y 3,9 % y la proteína (3,3; 3,4 y 3,4 %; en la lactosa y los sólidos totales se obtuvo un comportamiento similar. Se concluye que no hubo diferencias significativas en la producción y calidad de la leche en vacas de mediano potencial al incluir el probiótico Sorbifauna cuando estas pastan en un sistema silvopastoril, por lo que se recomienda evaluarlo en sistemas de gramíneas sin fertilizar.

  18. Gestión de la calidad de los cuidados de enfermería hospitalaria basada en la evidencia científica

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    Jesús Molina Mula

    Full Text Available La aplicación de los resultados de la investigación garantizará una gestión de la calidad de los cuidados de excelencia. El objetivo fue el de evaluar la calidad de atención de enfermería identificando los obstáculos para implementar la Práctica Clínica Basada en la Evidencia mediante el cuestionario Nursing Work Index. Se desarrolló un estudio observacional descriptivo transversal de los Hospitales del Ministerio de Salud Pública de Imbabura (Ecuador en la que participaron 120 enfermeras. Los resultados reflejan que existe poca participación de la enfermera en los asuntos del hospital, poco apoyo por parte de los gestores e inadecuada dotación de plantilla. Se han observado asociaciones entre estas categorías y los años de edad, profesión y años en la unidad. Se concluye que los gestores deben ser conscientes de cómo estos factores están impactando de forma directa en la calidad de los cuidados y establecer estrategias que vayan dirigidas a mejorar los indicadores de calidad.

  19. Diez claves pedagógicas para promover buenas prácticas en la formación médica basada en competencias en el grado y en la especialización

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    Pilar Ruiz de Gauna

    2015-01-01

    Full Text Available Durante la pasada década, la formación basada en competencias ha sido un término muy utilizado en Educación Médica. Los autores de este artículo argumentan que aunque se han desarrollado cambios relevantes en algunas facultades y centros sanitarios de formación de especialistas, en muchos otros lo único que ha cambiado es el nombre de las cosas para continuar haciendo lo mismo y no producir ninguna modificación en el perfil competencial de los estudiantes y los residentes. También se da el caso de instituciones que ni siquiera se plantean algún tipo de movimiento. Sin embargo, la situación social actual requiere pensar en una educación basada en competencias y establecer perfiles competenciales que respondan a las nuevas necesidades sociosanitarias. Por ello, el paso de una formación tradicional a una formación mediante competencias tiene que generalizarse y consolidarse en las instituciones educativas y sanitarias. Los autores del artículo argumentan que el cambio de la formación tradicional a otra apoyada en competencias tiene que liderarse desde las direcciones, los gestores y los docentes/tutores, y que las decisiones que ellos adopten han de estar fundamentadas en un marco pedagógico que concretan en 10 claves pedagógicas. Finalmente, concluyen que los currículos y programas de formación asentados en estas claves pedagógicas garantizan tanto el desarrollo de un perfil competencial de estudiantes y residentes comprometidos con un mundo más humano y más justo como el desarrollo de una buena práctica de formación en Educación Médica.

  20. Efecto de la poda en el rendimiento de biomasa de 20 accesiones de especies arbóreas Effect of pruning on the biomass yield of 20 accessions of tree species

    Directory of Open Access Journals (Sweden)

    Odalys C Toral

    2007-09-01

    Full Text Available Se evaluó el comportamiento de 20 accesiones de arbóreas ante la poda, durante cinco años, para lo cual se utilizó un diseño de bloques al azar con ocho repeticiones. Se determinó la biomasa comestible, la biomasa leñosa y la biomasa total, así como la composición bromatológica y el número de rebrotes. En el período lluvioso manifestaron un mejor comportamiento, en cuanto al rendimiento de biomasa, L. macrophylla CIAT-17240 y L. leucocephala CIAT-17498 (3,02 y 3,15 kg de MS/árbol como promedio. El número de rebrotes osciló entre 7 y 24 y la de mejor resultado fue L. leucocephala CIAT-17498 (24 rebrotes por planta. Sin embargo, en el período poco lluvioso la producción de biomasa comestible fluctuó entre 0,10 y 1,25 kg de MS/árbol, y se destacó de nuevo L. leucocephala CIAT-17498. Un comportamiento similar al del período lluvioso se constató en los indicadores restantes. Se concluye que los mejores resultados en cuanto a la producción de biomasa comestible se encontraron en el período lluvioso; se destacó L. leucocephala CIAT-17498 en este indicador y en el número de rebrotes para ambas épocas del año. Los contenidos de materia seca, fibra bruta y proteína bruta de la biomasa comestible de las plantas, tuvieron poca variación por el efecto de la época dentro de la misma especie, tendencia que se comprobó también para los minerales. Las accesiones demostraron ser una importante alternativa para la alimentación de los rumiantes, por sus altos contenidos de proteína bruta.The performance of 20 tree accessions when pruned was evaluated during five years, for which a randomized block design with eight repetitions was used. The edible, ligneous and total biomass, as well as the bromatological composition and number of regrowths were determined. In the rainy season L. macrophylla CIAT-17240 and L. leucocephala CIAT-17498 showed a better performance, regarding biomass yield (3,02 and 3,15 kg DM/tree as average. The

  1. Prácticas psicológicas basadas en la evidencia: beneficios y retos para Latinoamérica

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    Alfonso Martínez-Taboas

    2015-04-01

    Full Text Available Este artículo presenta las características medulares de las prácticas psicológicas basadas en la evidencia (PPBE. Enfatiza en que las PPBE son un movimiento internacional, que se ha integrado al abordaje de la salud por gobiernos y una amplia plétora de organizaciones profesionales. La investigación actualizada apunta al hecho que las PPBE usualmente maximizan resultados positivos en muchas poblaciones. Las PPBE plantean la integración de tres variables al momento de realizar una intervención psicológica: (a la utilización de la mejor evidencia disponible, que provee la Psicología para la toma de decisiones, (b considerar las preferencias y características culturales de la población a la cual se dirige la intervención y (c integrar el peritaje y la experiencia profesional del psicólogo. El artículo evalúa las adaptaciones culturales de diferentes PPBE y presenta evidencia que estas intervenciones producen mejores resultados comparados con intervenciones no adaptados. Revisa asuntos fundamentales como la internacionalización del fenómeno de las PPBE, su aplicabilidad y la efectividad en diferentes escenarios y su adaptabilidad con diferentes etnias y razas. Finalmente, se discuten posibles beneficios y barreras de transportar las PPBE a países latinoamericanos. Se utiliza el ejemplo de Puerto Rico para documentar cómo la Psicología puertorriqueña paulatinamente se ha movido por esta línea.

  2. La información científica de calidad, aliada esencial de la Medicina Basada en la Evidencia

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    Jorgelina Jiménez Miranda

    2003-02-01

    Full Text Available La Medicina Basada en la Evidencia (MBE se ha convertido en una nueva orientación de la práctica médica y en un paradigma científico actual, en el cual la investigación clínica desempeña un papel preponderante y pretende modificar la forma de ejercer la actividad asistencial, por lo que se considera un instrumento para la gestión del conocimiento clínico. En el artículo se define su concepto, antecedentes e historia, así como el papel que ha jugado la Colaboración Cochrane en su desarrollo y el rol que desempeña la información en este proyecto. Se recogen una serie de fuentes de información de calidad, especializadas en MBE, organizadas en bases de datos, Centros Cochrane, publicaciones y sitios Web.Evidence-based medicine has become a new orientation of medical practice and a current scientific paradigm where the clinical research plays a preponderant role and aims at changing the way in which assistance activity is carried out, therefore, evidence-based medicine is considered a clinical knowledge management tool. The article defines its concept, antecedents and history as well as the role of Cochrane Collaboration in its development and also the role of information in this project. A number of quality information sources specialized in evidence-based medicine and organized in databases, Cochrane centers, publications and Web sites are gathered.

  3. Aula virtual basada en la teoria costructivista empleada como apoyo para la enseñanza de los sistemas operativos a nivel universitario

    Directory of Open Access Journals (Sweden)

    Karla Cecilia Reyes Burgos

    2008-01-01

    Full Text Available La presente investigación propone el diseño e implementación de un aula virtual basada en la teoría constructivista, empleada como apoyo para la enseñanza de los sistemas operativos con los estudiantes durante el ciclo 2006-1 de la Universidad Católica Santo Toribio de Mogrovejo. Ello además nos impulsó a conocer las características que presentan las plataformas de gestión de aprendizaje, especialmente la utilizada para ésta investigación, Moodle y valorar el desempeño del aula virtual respecto al aspecto visual, de navegabilidad, contenidos y diseño instruccional. La metodología empleada fue de tipo descriptiva y en la organización de las tareas a llevar a cabo se emplearon técnicas del pensamiento sistémico. Finalmente el desempeño del aula virtual fue calificado de muy bueno en los aspectos visual, de navegabilidad, contenidos y diseño instruccional. Recomendando el posible uso de aulas virtuales como apoyo en asignaturas de nivel universitario y de formación contínua.

  4. Diseño y contrucción de una herramienta tecnológica basada en técnicas de procesamiento de lenguaje natural y aprendizaje automático para clasificación de correos de una entidad bancaria

    OpenAIRE

    González Herrero, Daniela

    2017-01-01

    El objetivo del proyecto es diseñar una aplicación tecnológica basada en el Procesamiento de Lenguaje Natural y algoritmos estadísticos de Aprendizaje Automático para clasificar de forma automatizada correos de clientes corporativos en una Entidad Bancaria. Actualmente el proceso de clasificación de los correos que envían los clientes corporativos es realizado por 14 operarios, y diariamente se reciben alrededor de 7000 correos, el equipo de operarios debe leer cada correo y en función de su ...

  5. Medidas para el fomento del derecho de las mujeres a una vida libre de violencias basadas en género (V.B.G) a partir de las causas del feminicidio del 2013 en la Comuna 10 de Cali

    OpenAIRE

    Jordán Camacho, Óscar Eduardo; Ortiz Ramírez, Juan Pablo

    2016-01-01

    El estudio sobre las medidas para el fomento del derecho de las mujeres a una vida libre de violencias basadas en género (V.B.G) a partir de las causas del feminicidio en la comuna 10 de Cali no ha sido objeto de investigaciones. No obstante, se han realizado estudios sobre el tema de la violencia contra la mujer, entre los cuales se destacan los siguientes: Ruiz (2000), “La violencia contra la mujer en la sociedad actual: análisis y propuestas de prevención”, en este estudio se reflexiona...

  6. La valoración de inversiones productivas: Una aproximación metodológica basada en la creación de valor financiero e intelectual

    Directory of Open Access Journals (Sweden)

    M. Dolores Guerrero-Baena

    2013-12-01

    Full Text Available Objeto: El objetivo de este artículo es presentar una novedosa metodología de valoración de inversiones productivas basada en la estimación del valor total creado con cada proyecto de inversión, considerando para ello sus dos componentes: el valor financiero y el valor del capital no financiero, este último derivado del capital intelectual corporativo. Diseño/metodología: Se propone una metodología basada en la técnica multicriterio del proceso analítico jerárquico (AHP, por sus siglas en inglés. En este modelo, se definen cuatro criterios principales (capital financiero, capital humano, capital estructural, y capital relacional, varios subcriterios y las alternativas de inversión. Para determinar el valor total de cada alternativa, se requieren juicios de valor por parte de los directores generales de las empresas, información obtenida a través de un cuestionario basado en comparaciones pareadas, cuyos resultados alimentan una función de utilidad multiatributo. Un caso de estudio del sector agroalimentario ilustra la aplicabilidad práctica del modelo. Aportaciones y resultados: La aplicación empírica evidencia la necesidad de considerar el impacto de las inversiones productivas en el capital intelectual de la empresa, pues este impacto influye en la selección de la alternativa de inversión óptima. Limitaciones: Las conclusiones alcanzadas se consideran aún provisionales, dado que se trata de un estudio pionero con una aplicación empírica reducida a sólo cinco empresas. Implicaciones prácticas: Mediante el modelo teórico propuesto, los directores generales pueden valorar las inversiones productivas incorporando en el análisis, de manera formalizada, la creación de valor del capital no financiero. Este procedimiento permite tomar decisiones más adecuadas, contribuyendo de manera efectiva a seleccionar la alternativa de inversión que maximice el valor de mercado de la compañía. Valor añadido: Como principal

  7. Revisión sistemática sobre la efectividad de intervenciones basadas en la comunidad en la disminución de la mortalidad neonatal

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    Adrián V Hernández

    Full Text Available Se evalúa la eficacia/efectividad de las intervenciones basadas en la comunidad, destinadas a disminuir la mortalidad neonatal. Se realizó una revisión sistemática de ensayos controlados aleatorizados, ensayos aleatorizados de comunidad y estudios de cohortes de intervenciones dirigidas a la mujer gestante, al neonato (hasta 28 días de nacido o a ambos. Se evaluaron 34 estudios (n=844,989: 20 en mujeres gestantes (n=406,172; 6 en neonatos (n=24,994, y 8 en ambos grupos (n=413,823. El riesgo de sesgo fue generalmente bajo. Hubo heterogeneidad entre los tipos de intervenciones. Las intervenciones educación materna en salud y cuidado en casa de madres y neonatos estuvieron asociadas con disminución de mortalidad neonatal en la mitad de los seis estudios de cada grupo. La suplementación materna con multimicronutrientes, el cuidado de madre canguro y la suplementación materna prenatal con vitamina A no disminuyeron la mortalidad neonatal. Pocas intervenciones comunitarias heterogéneas han demostrado disminuir la mortalidad neonatal.

  8. Enfermagem baseada em evidências: princípios e aplicabilidades Enfermería basada en evidencia: princípios y aplicabilidad Evidence based nursing: principles and applicability

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    Edvane Birelo Lopes De Domenico

    2003-02-01

    Full Text Available O trabalho discorre sobre a enfermagem baseada em evidências, como um novo modelo operacional integralizador da competência clínica individual, com os achados clínicos gerados pelas pesquisas científicas, e analisa a inserção dessa prática no modelo profissional vigente na enfermagem.El presente trabajo trae la práctica basada en evidencias como un nuevo modelo operacional integralizador de la competencia clínica individual con los avances clínicos generadas por las investigaciones científicas y analiza la inclusión de esta practica en el modelo profesional vigente en enfermería.The work considers the evidence based nursing as a new operational model that integrates individual clinical competencies, through clinical finding generated by scientific research and analyzes the inclusion of this practice to the actual nursing professional model.

  9. OneWeb: plataforma de adaptación de contenidos web basada en las recomendaciones del W3C Mobile Web Initiative

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    Francisco O. Martínez P.

    2011-01-01

    Full Text Available Las limitaciones con respecto a la experiencia de navegabilidad y facilidad de uso constituyen los principales obstáculos que enfrenta la web móvil para lograr una amplia aceptación mundial. Recientemente el W3C ha desarrollado una iniciativa conocida como Mobile Web Initiative (MWI, la cual define un conjunto de directrices para el diseño y presentación adecuada de interfaces web dirigidas a dispositivos móviles. El presente artículo describe las principales características y los módulos funcionales de OneWeb, una plataforma de adaptación de contenidos basada en las recomendaciones de MWI, desarrollada por el Grupo de Interés en el Desarrollo de Aplicaciones Móviles para Dispositivos Móviles - W@PColombia, adscrito al Grupo de Ingeniería Telemática de la Universidad del Cauca. Adicionalmente se presentan medidas de rendimiento y una comparación con sistemas de adaptación de contenido que operan actualmente. De manera experimental se obtuvieron tiempos de respuesta satisfactorios para entornos web móviles y se logró el cumplimiento de las recomendaciones de MWI sobre un conjunto de veinte páginas de prueba.

  10. Evaluación económica de proyectos de inversión basada en la teoría de opciones reales

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    Ignacio Andres Garrido Concha

    2003-07-01

    Full Text Available En la presente investigación se analiza un nuevo enfoque, basado en la aplicación de la Teoría de Opciones Reales para realizar la evaluación económica de proyectos de inversión. El mismo, posee el potencial de entregar una aproximación del valor de la flexibilidad que posee un proyecto, permitiendo al evaluador capturar numéricamente el valor de la estrategia. El objetivo fundamental de la presente investigación fue proponer una “Metodología de Evaluación Económica de proyectos de inversión a partir de la Teoría de Opciones Reales”, con el fin de presentarla como una herramienta de evaluación alternativa a los métodos tradicionales. A modo de aplicación de esta metodología, basada en el Método Binomial con Transformada Logarítmica, se realizó la evaluación económica de distintos proyectos reales los cuales corresponden a distintas variaciones del proyecto “Implementación de un Sistema de Información Geográfica (SIG para controlar la cartografía de las plantaciones pertenecientes a Forestal Mininco S.A” estudiadas previamente por Julio Becker.  

  11. Soil-root Shear Strength Properties of Some Slope Plants

    International Nuclear Information System (INIS)

    Normaniza Osman; Mohamad Nordin Abdullah; Faisal Haji Ali

    2011-01-01

    Rapid development in hilly areas in Malaysia has become a trend that put a stress to the sloping area. It reduces the factor of safety by reducing the resistant force and therefore leads to slope failure. Vegetation plays a big role in reinforcement functions via anchoring the soils and forms a binding network within the soil layer that tied the soil masses together. In this research, three plant species namely Acacia mangium, Dillenia suffruticosa and Leucaena leucocaphala were assessed in term of their soil-root shear strength properties. Our results showed that Acacia mangium had the highest shear strength values, 30.4 kPa and 50.2 kPa at loads 13.3 kPa and 24.3 kPa, respectively. Leucaena leucocaphala showed the highest in cohesion factor, which was almost double the value in those of Dillenia suffruticosa and Acacia mangium. The root profile analysis indicated Dillenia suffruticosa exhibited the highest values in both root length density and root volume, whilst Leucaena leucocaphala had the highest average of root diameter. (author)

  12. Mecanismos neurocognitivos de la terapia basada en mindfulness / Neurocognitive mechanisms of the mindfulness based therapy

    Directory of Open Access Journals (Sweden)

    Manolete S. Moscoso

    2015-12-01

    Full Text Available RESUMEN Presentamos un resumen y una breve historia del creciente campo de Intervenciones Basadas en mindfulness o conciencia plena. En los últimos tiempos, existe un gran interés en este modelo terapéutico para reducir la vulnerabilidad al estrés crónico y distrés emocional. Mindfulness requiere intencionalmente enfocar nuestra atención a las experiencias que ocurren en el momento presente. A medida que la investigación avanza en esta temática, es vital definir cuidadosamente la estructura de mindfulness y comprender mejor sus mecanismos de acción neurocognitiva. Este informe presenta un marco conceptual que enfatiza el papel central de control atencional y mecanismos de sostenibilidad para desarrollar las habilidades de conciencia plena. También, repasamos la estructura de mindfulness y la autorregulación de las emociones; luego describimos brevemente nuestra investigación relacionada con nuestro programa de Reducción del Estrés en Cáncer de Mama basado en Mindfulness (MBSR-AC en la University of South Florida. Se presenta, a partir de esta premisa, un modelo propuesto que explica nuestros mecanismos cognitivos basados en la lógica del modelo de biocomportamental. ABSTRACT We are presenting an overview and a brief history of the growing field of Mindfulness Based Interventions. There has been a significant interest in this therapeutic model to reduce vulnerability to chronic stress and emotional distress in recent times. Mindfulness requires intentionally bringing our attention to the experiences that occur in the present moment. As the research advances in this line of inquiry, it is vital to carefully define the construct of Mindfulness and better understand its neurocognitive mechanisms of action. This review presents conceptual framework that emphasizes the central role of attentional control and sustainability mechanisms to build mindfulness skills. We also review the construct of Mindfulness and self-regulation of

  13. A teoria fundamentada nos dados como abordagem da pesquisa interpretativa La teoría basada en datos como abordaje de la investigación interpretativa Grounded theory as an approach of interpretative research

    Directory of Open Access Journals (Sweden)

    Silvia Helena De Bortoli Cassiani

    1996-12-01

    Full Text Available Pesquisa interpretativa envolve os estudos da linha qualitativa e a pesquisa indutiva. Na classificação apresentada por LOWENBERG (1994 a teoria fundamentada nos dados é um tipo de pesquisa interpretativa situada como uma variante dentro do interacionismo simbólico. Face à pouca utilização desta metodologia nos estudos nacionais, este estudo teve por objetivo tratar da teoria fundamentada nos dados, enquanto referencial metodológico, apresentando e indicando seu método. As seguintes etapas foram apresentadas: coleta dos dados empíricos, os procedimentos de codificação ou análise dos dados; codificação aberta, codificação axial ou formação e desenvolvimento do conceito; codificação seletiva ou modificação e integração do conceito e delimitação da teoria. Os estudos de CALIRI (1994 e de CASSIANI (1994 exemplificaram a utilização deste referencial metodológico. Finalmente visualizou-se a metodologia da teoria fundamentada os dados como um referencial de análise que fornece caminhos e orienta, através de suas etapas, o investigador que pretende utilizá-la.La investigación interpretativa envolve estudios de la línea cualitativa y la investigación inductiva. En la clasificación presentada por LOWENBERG (1994 la teoría basada en datos es un tipo de investigación interpretativa situada como una variante del interaccionismo simbólico. El propósito de la presente investigación fue estudiar la teoría basada en datos, como un referencial metodológico, presentando y indicando su método. Las siguientes etapas fueron presentadas: colecta de datos empíricos, los procedimientos de codificación o análisis de datos; codificación abierta, codificación axial o formación y desarrollo del concepto; codificación selectiva o modificación y integración del concepto y delimitación de la teoría. Los estudios de CALIRI (1994 y de CASSIANI (1994 pusieron por ejemplo la utilización de esta referencia metodológica. En

  14. Mineral analysis of the forages as ruminant feed using x-ray fluorescent spectrometry (XRF)

    International Nuclear Information System (INIS)

    Sasangka, B.H.; Tjiptosumirat, T.; Suharyono

    1998-01-01

    An experiment was conducted to evaluate mineral contents of forages as feed. Samples used in this experiment were maize straw, cassava leaf, leucaena leaf, king grass, teki grass, Imperata cyliandria and field grass. These samples were collected from several locations of ranches in Mataram, Lombok island samples were measured for dry matter content, and then were formed into pellet in the size of diameter 3 cm and 0,1 cm thick, as required by the XRF analysis. Excitation of 1 0 9 Cd and 5F e radioisotopes were used as the initial energy for XRF analysis. Result of the analysis of macro elements show that P content was below the detection limit of XRF for Imperata cycliandrica and field grass, while for other samples were between 0.80 % In all samples S content were between 0.12 and 0.33% Potassium content in leucaena and cassava leaves were low ; i.e. 2.49 and 1.28% respectively, however, the concentration of Ca was high in these samples, i.e. 2.13 and 0.74%, respectively. Except leucaena leaves, which was found to be the lowest, result of micro elements analysis showed that Si ranged between 0.34 and 3.24%. On the other hand, Cr content in leucaena leaves was the highest, i.e. 104 ppm, as compared to the other foragers which were undetectable. Manganese was also found undetectable in maize straw and grass, while on other forages ranged between 65.50 and 178 ppm. Cobalt was only detected in maize straw, which is 27.6 ppm. All forage samples contained Cu and Zn with an average range 4.10 - 6.84 ppm and 43.30 - 73.50 ppm, respectively. (author)

  15. Mineral analysis of the forages as ruminant feed using x-ray fluorescent spectrometry (XRF); Analisis kandungan mineral dalam hijauan pakan ternak dengan menggunakan spektrometri pedar sinar-x

    Energy Technology Data Exchange (ETDEWEB)

    Sasangka, B H; Tjiptosumirat, T; Suharyono, [Center for Application of Isotopes and Radiation National Atomic Energy Agency Indonesia(Indonesia)

    1998-07-01

    An experiment was conducted to evaluate mineral contents of forages as feed. Samples used in this experiment were maize straw, cassava leaf, leucaena leaf, king grass, teki grass, Imperata cyliandria and field grass. These samples were collected from several locations of ranches in Mataram, Lombok island samples were measured for dry matter content, and then were formed into pellet in the size of diameter 3 cm and 0,1 cm thick, as required by the XRF analysis. Excitation of {sup 109}Cd and {sup 5}Fe radioisotopes were used as the initial energy for XRF analysis. Result of the analysis of macro elements show that P content was below the detection limit of XRF for Imperata cycliandrica and field grass, while for other samples were between 0.80 % In all samples S content were between 0.12 and 0.33% Potassium content in leucaena and cassava leaves were low ; i.e. 2.49 and 1.28% respectively, however, the concentration of Ca was high in these samples, i.e. 2.13 and 0.74%, respectively. Except leucaena leaves, which was found to be the lowest, result of micro elements analysis showed that Si ranged between 0.34 and 3.24%. On the other hand, Cr content in leucaena leaves was the highest, i.e. 104 ppm, as compared to the other foragers which were undetectable. Manganese was also found undetectable in maize straw and grass, while on other forages ranged between 65.50 and 178 ppm. Cobalt was only detected in maize straw, which is 27.6 ppm. All forage samples contained Cu and Zn with an average range 4.10 - 6.84 ppm and 43.30 - 73.50 ppm, respectively. (author)

  16. Estudio cualitativo sobre la enseñanza de las medidas de tendencia central usando una estrategia didáctica basada en e-learning, en grado décimo de educación secundaria en la Institución Educativa Luis Eduardo Calvo Cano

    OpenAIRE

    Mateus, Eduar

    2012-01-01

    Esta investigación tiene como propósito implementar una estrategia didáctica basada en el e-learning para determinar el nivel de adquisición de los conceptos de media, mediana y moda, en los alumnos de un curso de grado décimo de Educación Secundaria. El proyecto está basado en el enfoque ontosemiótico propuesto por Godino, Batanero y Font (2007). Al finalizar la investigación se espera que los alumnos tengan mejor desempeño en la solución de situaciones problema que involucren el concepto de...

  17. Efecto de la aplicación de prácticas sostenibles en las características físicas, químicas y microbiológicas de suelos degradados

    Directory of Open Access Journals (Sweden)

    J. Murillo

    Full Text Available El objetivo del estudio fue evaluar el efecto de la aplicación de prácticas sostenibles en la evolución de las propiedades del suelo, en áreas deterioradas del departamento del Cesar. El diseño experimental fue de bloques completos al azar y se aplicó análisis de varianza. Se evaluaron dos tratamientos: testigo, basado en el manejo tradicional del productor, sin aplicación de prácticas de mejoramiento del suelo (sistema predominante en la zona; y experimental, que consistió en la aplicación de enmiendas inorgánicas y prácticas sostenibles al suelo: labranza apropiada, incorporación de abono verde (Vigna unguiculata y establecimiento de cobertura vegetal con gramíneas y leguminosas asociadas (Bothriochloa pertusa, Leucaena leucocephala y Clitoria ternatea. Se realizó una evaluación comparativa de las características físicas, químicas y microbiológicas del suelo, durante tres años. Existió tendencia al mejoramiento de las características físicas y químicas del suelo, debido al descenso de la densidad aparente (de 1,68 a 1,53 g cm-3 en los primeros 30 cm de profundidad, así como al aumento de la porosidad del suelo (de 33,28 a 41,2 %, la infiltración básica (de 0,5 a 1,3 mm h-1, la materia orgánica (de 0,97 a 1,40 % y el azufre (de 8,57 a 40,35 mg kg-1. Asimismo, no se incrementó la concentración de sodio ni la conductividad eléctrica. Los tratamientos no generaron alteraciones considerables en las poblaciones microbianas (bacterias, actinomicetos y hongos, lo que permite inferir que las prácticas aplicadas no causaron impactos negativos en la microbiota del suelo.

  18. Phenotypic, Molecular and Symbiotic Characterization of the Rhizobial Symbionts of Desmanthus paspalaceus (Lindm.) Burkart That Grow in the Province of Santa Fe, Argentina

    Science.gov (United States)

    Fornasero, Laura Viviana; Del Papa, María Florencia; López, José Luis; Albicoro, Francisco Javier; Zabala, Juan Marcelo; Toniutti, María Antonieta; Pensiero, José Francisco; Lagares, Antonio

    2014-01-01

    Desmanthus paspalaceus (Lindm.) Burkart belongs to the D. virgatus complex, subfamily Mimosoidae. The known potential as livestock fodder of several of these legumes prompted us to undertake a phenotypic, molecular, and symbiotic characterization of the D. paspalaceus symbionts in the Santa Fe province, Argentina. The rhizobia collected—containing isolates with different abiotic-stress tolerances—showed a remarkable genetic diversity by PCR fingerprinting, with 11 different amplification profiles present among 20 isolates. In selected isolates 16S-rDNA sequencing detected mesorhizobia (60%) and rhizobia (40%) within the collection, in contrast to the genus of the original inoculant strain CB3126—previously isolated from Leucaena leucocephala—that we typified here through its 16S rDNA as Sinorhizobium terangae. The results revealed the establishment by diverse bacterial genera -rhizobia, sinorhizobia, and mesorhizobia- of full N2-fixing symbiotic associations with D. paspalaceus. This diversity was paralleled by the presence of at least two different nodC allelic variants. The identical nodC alleles of the Mesorhizobia sp. 10.L.4.2 and 10.L.5.3 notably failed to group within any of the currently described rhizo-/brady-/azorhizobial nodC clades. Interestingly, the nodC from S. terangae CB3126 clustered close to homologs from common bean nodulating rhizobia, but not with the nodC from S. terangae WSM1721 that nodulates Acacia. No previous data were available on nod-gene phylogeny for Desmanthus symbionts. A field assay indicated that inoculation of D. paspalaceus with the local Rhizobium sp. 10L.11.4 produced higher aerial-plant dry weights compared to S. teranga CB3126–inoculated plants. Neither the mesorhizobia 10.L.4.2 or 10.L.5.3 nor the rhizobium 10L.11.4 induced root nodules in L. leucocephala or P. vulgaris. The results show that some of the local isolates have remarkable tolerances to several abiotic stresses including acidity, salt, and temperature

  19. The Use of Plant Bioactive Compounds to Mitigate Enteric Methane in Ruminants and its Application in Indonesia

    Directory of Open Access Journals (Sweden)

    Elizabeth Wina

    2012-03-01

    Full Text Available Worldwide, increasing greenhouse gas (GHG emissions have become a major concern as they are now considered to be the cause of global warming. Several strategies have been planned and taken by different countries including Indonesia to mitigate this situation. Agriculture is considered to be one of major contributors to GHG, especially methane coming from ruminant digestive processes. More than 85% of the methane produced by ruminants comes from enteric fermentation. Several options have been proposed to lower this enteric methane production. This paper describes a review on diet manipulation using feed additives, especially plant bioactive compounds, to mitigate the GHG emission from ruminant livestock. Plant bioactive compounds have been found with various chemical structures. Some of them such as saponin, tannin, essential oils, organosulphur compounds, have been reported to have ability to reduce enteric methane production. Indonesia has many plant resources that have potential as methane reducing agents. Sapindus rarak fruit especially its methanol extract contain saponins which reduce the activity of methanogens in the rumen in vitro, hence reduce methane production (11%. Feeding S. rarak to sheep increased daily weight gain but not that of local cattle. Shrub legumes such as Calliandra calothyrsus and Leucaena leucocephala contain tannins which can reduce methanogenesis (3 – 21% methane reduction. Besides tannin, these shrub legumes are a good source of protein. Feeding shrub legumes can be beneficial as a protein source and a methane reducer. Other sources of methane reducing agents have been tested in other countries and some can be applied for Indonesian situation. The strategy to reduce methane by plant bioactive compounds should be developed to be simple and relatively cheap so it will benefit the local farmers. Extraction of these compounds may be expensive, therefore, costs should be considered carefully when proposing to use the

  20. Estoque de serapilheira e fertilidade do solo em pastagem degradada de Brachiaria decumbens após implantação de leguminosas arbustivas e arbóreas forrageiras

    Directory of Open Access Journals (Sweden)

    André Barbosa Silva

    2013-04-01

    Full Text Available As pastagens formam a base da pecuária brasileira; essas sofrem degradação em larga escala por deficiência de nitrogênio (N. O consórcio com leguminosas, além de fixar N, pode apresentar outros efeitos na fertilidade do solo como acidificação ou retirada de nutrientes de camadas mais profundas para as mais superficiais. Este trabalho objetivou avaliar o estoque de serapilheira e a fertilidade do solo em pastagens degradadas de braquiária (Brachiaria decumbens, após implantar leguminosas arbustivas e arbóreas forrageiras. Para isso, uma amostragem foi realizada em março de 2010 em um experimento no campo, introduzindo pastagem degradada de Brachiaria decumbens, em julho de 2008, com sabiá (Mimosa caesalpiniifolia, leucena (Leucaena leucocephala, mororó (Bauhinia cheilantha e gliricídia (Gliricidia sepium, além de braquiária adubada e não adubada com N. As amostras de solo e serapilheira foram coletadas aos 0-10, 10-20 e 20-40 cm de profundidade, em três transectos, alternando pontos cobertos por gramíneas e leguminosas, totalizando sete amostras compostas por parcela para determinar pH, P, K, Ca, Mg e Al no solo, enquanto SB, t e m foram calculados. A serapilheira foi separada visualmente em leguminosas, gramíneas e materiais não identificados, em que foram utilizados para quantificação de matéria seca, matéria orgânica, N, P, C, fibra detergente ácido e lignina. A introdução das leguminosas aumentou os teores de N total na serapilheira e reduziu as relações C:N, com destaque para gliricídia e sabiá; entretanto, essa última apresentou elevados teores de lignina. Houve efeito significativo da cobertura por leguminosas, sem diferenças entre essas, para pH e K, na profundidade de 0-10 cm, e para Al e m, aos 10-20 cm de profundidade.

  1. Exo-oligosaccharides of Rhizobium sp. strain NGR234 are required for symbiosis with various legumes.

    Science.gov (United States)

    Staehelin, Christian; Forsberg, Lennart S; D'Haeze, Wim; Gao, Mu-Yun; Carlson, Russell W; Xie, Zhi-Ping; Pellock, Brett J; Jones, Kathryn M; Walker, Graham C; Streit, Wolfgang R; Broughton, William J

    2006-09-01

    Rhizobia are nitrogen-fixing bacteria that establish endosymbiotic associations with legumes. Nodule formation depends on various bacterial carbohydrates, including lipopolysaccharides, K-antigens, and exopolysaccharides (EPS). An acidic EPS from Rhizobium sp. strain NGR234 consists of glucosyl (Glc), galactosyl (Gal), glucuronosyl (GlcA), and 4,6-pyruvylated galactosyl (PvGal) residues with beta-1,3, beta-1,4, beta-1,6, alpha-1,3, and alpha-1,4 glycoside linkages. Here we examined the role of NGR234 genes in the synthesis of EPS. Deletions within the exoF, exoL, exoP, exoQ, and exoY genes suppressed accumulation of EPS in bacterial supernatants, a finding that was confirmed by chemical analyses. The data suggest that the repeating subunits of EPS are assembled by an ExoQ/ExoP/ExoF-dependent mechanism, which is related to the Wzy polymerization system of group 1 capsular polysaccharides in Escherichia coli. Mutation of exoK (NGROmegaexoK), which encodes a putative glycanase, resulted in the absence of low-molecular-weight forms of EPS. Analysis of the extracellular carbohydrates revealed that NGROmegaexoK is unable to accumulate exo-oligosaccharides (EOSs), which are O-acetylated nonasaccharide subunits of EPS having the formula Gal(Glc)5(GlcA)2PvGal. When used as inoculants, both the exo-deficient mutants and NGROmegaexoK were unable to form nitrogen-fixing nodules on some hosts (e.g., Albizia lebbeck and Leucaena leucocephala), but they were able to form nitrogen-fixing nodules on other hosts (e.g., Vigna unguiculata). EOSs of the parent strain were biologically active at very low levels (yield in culture supernatants, approximately 50 microg per liter). Thus, NGR234 produces symbiotically active EOSs by enzymatic degradation of EPS, using the extracellular endo-beta-1,4-glycanase encoded by exoK (glycoside hydrolase family 16). We propose that the derived EOSs (and not EPS) are bacterial components that play a crucial role in nodule formation in various legumes.

  2. Identification of Potential Plants Producing Tannin-protein Complex for a-amylase as Botanical Pesticide

    Directory of Open Access Journals (Sweden)

    Asriyah Firdausi

    2013-05-01

    Full Text Available Research  on  the  development  of  botanical  pesticides  should  be developed  through  new  methods,  such  as  by  inhibiting the  activity  of  digestive enzymes  by  secondary  metabolites.  The  aim  of  this  study  was  to  identify some  of  potential  plants  as  a  source  of  tannin-protein  complexes  to  inhibitthe  activity  of  - amylase.  The  study  of  identification  of  potential  plants producing  the  active  ingredient  tannin-protein  complex  was  divided  into  three stages,  1  identification  of  potential  plants  producing  tannin,  2  isolation  of tannin-protein  complexes,  and  3  in  vitro  test  of  tannin-protein  complexes effect  of  the  -amylase activity.  Some  of  the observed  plants  were  sidaguri  leaf (Sida rhombifolia, melinjo leaf (Gnetum gnemon, gamal leaf (Gliricidia sepium,lamtoro  leaf  (Leucaena  leucocephala ,  betel  nut  (Areca  catechu ,  and  crude gambier  (Uncaria  gambir a s  a  source of  tannins  and  melinjo  seed was  used  asprotein  source.  Betel  nut  and  melinjo  seed  were  the  best  source  of  tannin-protein  complex,  tannin  content  1.77  mg  TAE/mL  with  antioxidant  activity  of  90%,the  ability  to  inhibit  the  activity  of  -amylase by  95%  with  IC 50  values  of 10 mg/mL.Key words: Tannin, protein, -amylase, botanical pesticides,Areca catechu, Gnetum gnemon.

  3. Seguridad basada en parámetros SIM para entornos de comercio electrónico móvil

    Directory of Open Access Journals (Sweden)

    Francisco Orlando Martínez Pabón

    2007-05-01

    Full Text Available Los requerimientos de seguridad son los más exigentes en el dominio del comercio electrónico. Cuando se ha-bla de comercio electrónico móvil los requisitos a nivel de seguridad no solo conservan su nivel de exigencia, sino que se debe mantener un equilibrio entre el grado de seguridad que se requiere y las capacidades de los dispositivos, tanto a nivel hardware como de usabilidad. Estas características exigen el diseño de modelos con un esquema simple de autenticación y autorización transparente para los usuarios, que además garantice la integridad de la información que se intercambia durante cualquier transacción electrónica. Como respuesta a esta necesidad, el Grupo de Interés en el Desarrollo de Aplicaciones Móviles e Inalámbricas W@PColombia, ha desarrollado la plataforma P3SIM con el objeto de brindar las facilidades necesarias para la construcción de aplicaciones móviles seguras basadas en parámetros SIM; a través de un framework, un ambiente de compilación y de simulación como sus principales componentes, la plataforma P3SIM combina las ventajas de identificación que proporciona el módulo SIM con las capacidades que en materia de seguridad ofrecen API como SATSA y JavaCard en el entorno Java ME, una de las plataformas más utilizadas en el desarrollo de aplicaciones para dispositivos móviles. Igualmente, a través del desarrollo de un prototipo aplicado al contexto del comercio elec-trónico móvil, no solo se demuestran las facultades de la plataforma para operar en ambientes seguros sino también su capacidad de adaptación a los requerimientos de seguridad fijados por el entorno.

  4. Diseño de estrategias de marketing, comunicación y comercialización basadas en modelos de marketing digital business to business B2B y business to consumers B2C para las pymes de calzado de la provincia de tungurahua agremiadas a la CALTU

    OpenAIRE

    León Naranjo, Mario Andrés

    2015-01-01

    1. Introducción.-- 2.Planteamiento de la propuesta de trabajo.-- 3.Marco teórico.-- 4.Metodología.-- 5.Resultados.-- 6.Concluisones y recomendaciones La presente investigación académica tiene como objetivo principal diseñar estrategias de marketing, comunicación y comercialización basadas en modelos de marketing digital Business to Business B2B y Business to Consumers B2C para las pymes de calzado de la provincia de Tungurahua agremiadas a ala CALTU. Este trabajo investigativo se basa en e...

  5. METODOLOGÍA BASADA EN LOS ALGORITMOS VEGA Y MOGA PARA SOLUCIONAR UN PROBLEMA MULTIOBJETIVO EN UN SISTEMA DE PRODUCCIÓN JOB SHOP

    Directory of Open Access Journals (Sweden)

    Germán Augusto Coca Ortegón

    Full Text Available En este artículo se presenta una metodología que pretende minimizar de forma simultánea, en un ambiente de producción tipo "job shop" correspondiente a una empresa metalmecánica, las siguientes variables: tiempo de proceso, costo de mano de obra directa y, asimismo la fracción defectuosa generada por la fatiga del operario. Con este propósito se fusionan elementos de los algoritmos genéticos Vega y Moga, desarrollando para el efecto las siguientes etapas: generar la población inicial, conformar la nueva población, realizar análisis de varianza y por último, comparar con un método híbrido entre sumas ponderadas y algoritmos genéticos. De acuerdo con lo anterior, al evaluar el individuo de menor tiempo de proceso proveniente de la metodología basada en los algoritmos Vega y Moga, respecto al individuo de menor tiempo de desarrollo proveniente del método híbrido entre sumas ponderadas y algoritmos genéticos, se encuentra que el primero supera en desempeño al segundo así: en cuanto a la variable tiempo de proceso (en horas en 27,86%; en cuanto a la variable tiempo de proceso (en semanas en 1,25%; en cuanto a la variable costo de mano de obra directa (MOD en 6,73% y, en cuanto a la variable fracción defectuosa en 25,85%.

  6. Herramientas y propuestas de innovación basadas en la tecnología de realidad aumentada aplicadas a la literatura infantil y juvenil / Tools and proposals for innovation based on augmented reality technology applied children's literature

    Directory of Open Access Journals (Sweden)

    Noelia Margarita Moreno Martínez

    2017-01-01

    Full Text Available Resumen En la sociedad de la información en la que nos encontramos inmersos la proliferación y el auge que están teniendo hoy en día dispositivos como smartphone, tablet, phablet se manifiesta en la asunción de nuevos modelos de aprendizaje, formas de vida, de comunicación, relaciones y entretenimiento por parte del ciudadano de la nueva era digital. Así pues, el desarrollo de estrategias para implantar estas nuevas herramientas tecnológicas en el aula supone una oportunidad para replantearnos la práctica educativa acorde con las nuevas características, demandas y necesidades del alumnado diverso al que se atiende, aprovechando así las posibilidades que nos ofrecen las tecnologías emergentes como la realidad aumentada (RA bajo una nueva modalidad de aprendizaje basada en Mobile Learning. En el presente trabajo realizaremos una revisión y análisis de aplicaciones móviles basadas en la tecnología de realidad aumentada para entornos Android e iOs y, posteriormente, presentaremos propuestas de actividades para la implementación de dicha tecnología en el abordaje de la literatura infantil y juvenil. Abstract In our society´s information where we are immersed there is a boom about devices such as smartphone, tablet, phablet. They are reflected in the assumption of new learning models, lifestyles, communication, relationships and entertainment by citizens of the new digital era. Thus, the development of strategies to implement these new technological tools in the classroom is an opportunity to rethink the line educational practice with new features, demands and needs of diverse student. They are attending and take advantage of the possibilities offered by emerging technologies as augmented reality in a new mode of learning based on Mobile Learning. In this paper, we review and analysis of mobile applications based on augmented reality technology developed for Android and iOS environments, and we will present activities for the

  7. Clasificación de la variación conceptual de los términos basada en la modulación semántica discursiva

    Directory of Open Access Journals (Sweden)

    Irina Kostina

    2011-04-01

    Full Text Available En este artículo se describe una propuesta de clasificación de la variación conceptual proyectada en procesos polisémicos regulares e irregulares a los que están sometidos los términos como unidades léxicas en el discurso. Se sigue la metodología basada en corpus especializado para recuperar los contextos definitorios y explicativos por medio de los patrones metalingüísticos. Los datos se analizan cuantitativa y cualitativamente. Se aplica el eje de la equivalencia conceptual como instrumento metodológico para el análisis semántico de comportamiento de los términos en contextos de uso. El 81% de la muestra corresponde a la variación conceptual proyectada en los procesos polisémicos regulares, mientras que el 14% de la misma corresponde a la variación proyectada en procesos polisémicos irregulares. Los casos mixtos de variación comprenden a un 5%. Por otro lado, se proponen los criterios para distinguir los sentidos de un mismo concepto denominado por un término o sus variantes léxico-semánticas. Se espera que el presente estudio tenga un impacto en las investigaciones sobre desambiguación de significados de términos en contexto.

  8. DiagWeb: Una experiencia de enseñanza basada en proyectos tutorados en Educación Superior mediante una WebQuest alojada en Moodle

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Gómez Ruiz

    2010-01-01

    Full Text Available Nos encontramos en un momento de cambios en la Educación Superior que favorece la indagación sobre la utilización de los recursos virtuales como mediadores del proceso de aprendizaje. En este contexto hemos diseñado e implementado la DiagWeb, una Página Web basada en la estructura y filosofía de la WebQuest, pero en vez de estar orientada a la resolución de un interrogante, posee el objetivo de guiar, orientar y organizar la creación autónoma de proyectos tutorados en el contexto universitario. Se han subido los archivos HTML que componían la Web a un directorio de Moodle (Campus Virtual de la asignatura, haciendo las veces de servidor y ofreciendo la posibilidad de añadir aplicaciones para la comunicación, para ofrecer proalimentación y para centralizar los recursos ofrecidos gracias a este Sistema de Gestión de Aprendizaje. En este escrito describimos la base teórica de la DiagWeb, su composición y puesta en práctica con 130 estudiantes del último curso de una licenciatura de educación. Por último, se ofrecen los resultados de un cuestionario dirigido a recoger la percepción y valoraciones de los participantes implicados en la experiencia.

  9. Evaluation of phospherus uptake from Minjingu phosphate rock, growth and nodulation of agroforestry tree species on an acid soil from Kenya

    International Nuclear Information System (INIS)

    Karanja, N.K.; Mwendwa, K.A.

    2002-01-01

    A series of studies were carried out to study the effect of P application on fast growing multi-purpose trees. A greenhouse experiment was conducted to evaluate availability and uptake of phosphorus (P) from Minjingu phosphate rock (MPR). An acid soil and six agroforestry tree species namely Leucena leuco-cephala, Gliricidia sepium, Sesbania sesban, Grevillea robusta, Cassia siamea and Eucalyptus grandis were used. Phosphorus was applied at 25.8 mg P/ kg soil as Minjingu phosphate rock (MPR) or Triple Superphosphate (TSP). Pregerminated seedlings were transplanted and divided into two sequential harvests at 3 and 6 MAT (months after transplanting). 32 P isotope carrier free solution was added to transplanted seedlings at the beginning and when they were 3 months old. The soil was tested for isotopically exchangeable P by incubating the soil with the MPR and TSP. The soil was high in P-fixing capacity. At 3 MAT all the species except G. robusta gave a 150-250% significantly higher stem dry weights where P was added and L. leuco-cephala, S. sesban and C. siamea maintained this up to 6 MAT. The legumes and E. grandis where P was applied differed significantly from controls in root dry weight with Minjingu PR being superior with G.sepium and E. grandis. The legumes and E. grandis had significantly higher P uptake where P was applied at 3 MAT. The relative availability of MPR at 3 MAT showed that L.leucocephala and G. sepium derived 2.93 and 1.06 times more P from Minjingu PR than from TSP respectively. Data obtained from G. robusta P uptake showed that this species preferred soil P to externally supplied P in the three sampling periods. Tree species and fertilizer P interactions at 6 MAT were highly significant (P=0.01). Vesicular arbuscular mycorrhiza (VAM) inoculation improved growth, P uptake from MPR and nodulation of G. sepium seedlings. Inoculating L. leucocephala seedlings with VAM increased availability of P from MPR. (author)

  10. Status and conservation of parrots and parakeets in the Greater Antilles, Bahama Islands, and Cayman Islands

    Science.gov (United States)

    Wiley, J.W.

    1991-01-01

    In the 1490s a minimum of 28 species of psittacines occurred in the West Indies. Today, only 43% (12) of the species survive. All macaws and most parakeet species have been lost. Although the surviving parrot fauna of the Greater Antilles, Cayman Islands, and Bahama Islands has fared somewhat better than that of the Lesser Antilles, every species has undergone extensive reductions of populations and all but two have undergone extensive reductions in range, mostly as a result of habitat loss, but also from persecution as agricultural pests, conflicts with exotic species, harvesting for pets, and natural disasters. The Cayman Brac Parrot Amazona leucocephala hesterna with its tiny population (less than 150 individuals in the wild) and range, and the Puerto Rican Parrot A. vittata, with about 22-23 birds in the wild and 56 individuals in captivity, must be considered on the verge of extinction and in need of (in the latter's case, continuing) aggressive programmes of research and management. Other populations declining in numbers and range include the Yellow-billed Amazona collaria, and Black-billed A. agilis Parrots of Jamaica, Hispaniolan Parakeet Aratinga chloroptera, Hispaniolan Parrot Amazona ventralis, Cuban Parrot A. leucocephala leucocephala and, most seriously, Cuban Parakeet Aratinga euops. The population of the Grand Cayman Parrot (Amazona leucocephala caymanensis), although numbering only about 1,000 birds, appears stable and the current conservation programme gives hope for the survival of the race. An active conservation and public education programme has begun for the Bahama Parrot A. l. bahamensis, which still occurs in good numbers on Great Inagua Island, but is threatened on Abaco Island. Recommendations for conservation of parrots and parakeets in the region include (1) instituting long-term programmes of research to determine distribution, status, and ecology of each species; (2) developing conservation programmes through education and management

  11. Discapacidad, pobreza y sus abordajes: Revisión de la estrategia de rehabilitación basada en la comunidad (RBC Aproaches in disability and poverty: Review of community based rehabilitation strategy (CBR

    Directory of Open Access Journals (Sweden)

    Mariela Nabergoi

    2007-12-01

    Full Text Available El artículo presenta los resultados de una revisión bibliográfica sobre la estrategia de Rehabilitación Basada en la Comunidad (RBC. El mismo fue elaborado en el marco de los proyectos de Beca de Doctorado UBACyT "Desempeño ocupacional y salud en personas con discapacidad motriz en situación de pobreza" y Proyecto UBACyT "Praxis Psicosocial Comunitaria en Salud". Se describen antecedentes, características de la propuesta original, su evolución y algunas experiencias relevadas en América Latina.The article presents the results of a literature review on Community Based Rehabilitation (CBR. It was written within the framework of the Doctorate UBACyT Scholarship Project "Occupational Performance and Health in Motor Disabled People in Poverty Situation" and the UBACyT Project "Psychosocial Community Praxis in Health". Background, characteristics, evolution and some experiences in Latin America are described.

  12. Medicina basada en la evidencia: Aportes a la práctica médica actual y dificultades para su implementación

    Directory of Open Access Journals (Sweden)

    Germán Málaga Rodríguez

    2009-04-01

    Full Text Available Medicina basada en la evidencia (MBE es actualmente sinónimo de práctica médica moderna e innovadora. Sin embargo, poco se sabe de su real dimensión y principios. Su relación con la investigación y la "evidencia" es entendida como la interpretación de la literatura medica, la realización de mega ensayos clínicos o meta-análisis. MBE implica el uso juicioso de la mejor evidencia disponible, gracias a la evaluación rigurosa de la calidad metodológica de la información científica, así como de su aplicabilidad. La MBE rescata la experiencia y pericia clínica del médico. Adicionalmente, incorpora como tercer elemento fundamental las preferencias y valores de los pacientes acerca del cuidado de su salud. La intersección de estos tres aspectos constituye la esencia de la MBE. La práctica así entendida de la MBE ubica al paciente y sus circunstancias en el centro mismo del acto médico y lo revaloriza como "ciencia y arte". En esta revisión buscamos destacar como la práctica de la MBE guía hacia una toma de decisiones correcta y democrática. Así mismo, se revisa los diversos aportes en la práctica medica actual, las distorsiones creadas alrededor de ella y las limitaciones para su aplicación en nuestra realidad.(Rev Med Hered 2009;20:191-197.

  13. Recomendaciones para la fotoprotección en la edad pediátrica, una propuesta basada en evidencias científicas

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    Pilar María Acuña Aguilarte

    Full Text Available Introducción: el incremento mundial del cáncer de piel y otras afecciones relacionadas con las radiaciones ultravioletas ha sido reconocido por la Organización Mundial de la Salud, que ha llamado a trazar estrategias de prevención. En el mundo existen diferentes posturas relacionadas con la fotoprotección, y la Organización Mundial de la Salud, entre sus recomendaciones, enfatiza en no exponer a las radiaciones ultravioletas de forma directa a los niños menores de 1 año, pero las recomendaciones varían entre países y organismos internacionales. Objetivo: elaborar recomendaciones basadas en evidencias científicas para la fotoprotección de niños y adolescentes cubanos. Desarrollo: se empleó un diseño cualitativo, con un acercamiento de investigación documental. Se emplearon motores de búsqueda y bases de datos disponibles en la Biblioteca Virtual de Salud, y se buscaron descriptores relacionados con el tema de fotoprotección, publicados en inglés y español entre 2002 y el 2012. Se obtuvieron evidencias científicas sobre el incremento de las radiaciones ultravioletas y su influencia en el ser humano. Se realizaron recomendaciones que fueron evaluadas por un grupo de expertos en el tema. Conclusiones: los puericultores pueden disponer de recomendaciones actualizadas para la fotoprotección de niños y adolescentes sanos cubanos, entre las cuales se incluyen, evitar la exposición directa del recién nacido a las radiaciones solares hasta los 6 meses de vida, clasificar el fototipo cutáneo de cada niño o adolescente y ofrecer indicaciones diferenciadas, así como dirigir la educación en las medidas de fotoprotección a toda la familia y la comunidad.

  14. Mejoramiento de la comprensión lectora basada en el aprendizaje colaborativo en la enseñanza media básica

    Directory of Open Access Journals (Sweden)

    Manuel Arroyo Sarabia

    2010-10-01

    Full Text Available Ésta innovación educativa basada en evidencia, tuvo como objeto la lectura de comprensión a través de un proceso de transversalidad en las asignaturas de Ciencias, Español y Educación tecnológica, en segundo y tercer año de secundaria. Se utilizó la estrategia de aprendizaje colaborativo con la pretensión de facilitar la comprensión y motivar al alumno. El objetivo de la implementación fue que el alumno obtuviera el hábito de la lectura, motivado intrínsecamente con el recurso de la computadora e Internet. Se aplicó en cuatro entornos, variando la ubicación y el contexto económico-cultural y social, obteniendo así información para determinar los factores que influyen en el aprendizaje; se diagnosticó el problema, se indagó en libros electrónicos e impresos, se eligieron y aplicaron los instrumentos; y se validaron los resultados triangulando información. Para medir la efectividad del proyecto se utilizaron técnicas de análisis cualitativo antes, durante y después de la aplicación a los alumnos de baja comprensión lectora, verificándose una mejora en la comprensión e interés en la indagación de información. Finalmente, se concluyó que tanto la estrategia como los recursos utilizados ayudaron a la mejora de la comprensión lectora en alumnos de bajo nivel, lográndose los objetivos y en congruencia con los conceptos teóricos.

  15. Una representación basada en Semat y RUP para el Método de Desarrollo SIG del Instituto Geográfico Agustín Codazzi

    Directory of Open Access Journals (Sweden)

    Claudia Elena Durango Vanegas

    2015-06-01

    Full Text Available Los Sistemas de Información Geográfica (SIG constituyen un apoyo importante para el análisis y solución de problemas en áreas, como: salud, hidrología, ingeniería y gestión territorial, entre otras. El desarrollo metodológico de los SIG no incluye especificaciones propias; por el contrario, son propuestas modificadas de otros métodos, que contienen los mismos productos de trabajo, actividades y recursos de los métodos tradicionales de desarrollo, tales como el Rational Unified Process (RUP. Uno de esos métodos es del Instituto Geográfico Agustín Codazzi (IGAC. Semat (Teoría y Métodos de la Ingeniería de Software es una iniciativa que ayuda a capturar elementos esenciales y comunes, universales a todos los esfuerzos de desarrollo de software. En busca de las especificaciones propias de los métodos de desarrollo de SIGs, en este artículo se propone una representación basada en el núcleo de Semat del método IGAC para identificar la relación con el método tradicional Proceso Unificado de Racional (RUP. Con esta representación es posible determinar las prácticas asociadas con el método IGAC que se heredan de los métodos tradicionales.

  16. Retos del manejo de información sobre violencia basada en género (VBG en el marco del conflicto armado. El caso de Medellín

    Directory of Open Access Journals (Sweden)

    Paula Andrea Valencia Londoño

    2014-10-01

    Full Text Available El manejo de información sobre Violencia Basada en Género -VBG- en el marco de los conflictos armados, es un imperativo que encuentra sus orígenes en el trabajo constante del movimiento feminista desde la década del 70, que a su vez se tradujo en un cuerpo normativo que incluye exigencias sobre el seguimiento sistemático de la VBG como una de las consecuencias humanitarias del conflicto armado. No obstante, su puesta en marcha representa una serie de retos derivados, por un lado de las limitaciones en el rastreo del problema, y por otro, en el tratamiento de las fases de procesamiento y reporte de información, los cuales han sido evidenciados por el escaso constructo teórico existente alrededor del tema. La investigación de la cual deriva este texto analiza estos retos para el caso de algunas iniciativas en materia de manejo de información sobre consecuencias humanitarias y VBG existentes en Colombia, y en particular en Medellín, con el fin de dar claves para su potenciación y orientar ejercicios futuros a partir de la solución a los obstáculos presentes en los procesos actuales.

  17. Comparación de la prevalencia de discapacidades basada en auto-reportes en países de América Latina

    Directory of Open Access Journals (Sweden)

    Malena Monteverde-Verdenelli

    2014-01-01

    Full Text Available En general, la medición de prevalencias de discapacidades a nivel de población o de grandes muestras se basa en auto-reportes. Resulta de interés evaluar en qué medida dichos auto-reportes permiten realizar comparaciones entre grupos de población. El objetivo del presente trabajo es medir, comparar y analizar la consistencia de las comparaciones de la prevalencia de discapacidades en actividades de la vida diaria (AVD entre poblaciones de América Latina. El análisis incluye las poblaciones de Buenos Aires, Santiago de Chile, Sao Pablo, Ciudad de México, Montevideo y La Habana. Para evaluar la consistencia de las comparaciones basadas en auto-reportes, se estiman prevalencias de discapacidades en AVD y prevalencias de enfermedades crónicas relacionadas con la discapacidad. Luego se comparan los patrones observados en países con ambas condiciones. Las poblaciones de 60 años y más de Buenos Aires y Montevideo reportan menores dificultades para la realización de AVD y menores prevalencias de condiciones crónicas discapacitantes como diabetes, enfermedades pulmonares, enfermedades cerebrovasculares y problemas cognitivos. Sin bien ello sugiere que al menos parte de las diferencias de auto-reporte de discapacidades podrían deberse a diferencias de morbilidad, no se descarta la existencia de efectos por diferencias en factores contextuales o en las propensiones a reportar discapacidades, entre otros. En este sentido, sería de utilidad llevar a cabo estudios ad- hoc que permitan medir simultáneamente diagnósticos y auto-reportes, la implementar instrumentos como viñetas e incluir información sobre factores contextuales (al menos para sub- muestras, y así poder evaluar la existencia de sesgos sistemáticos y la importancia de factores contextuales en los auto-reportes de discapacidades.

  18. Comparación de la prevalencia de discapacidades basada en auto-reportes en países de América Latina

    Directory of Open Access Journals (Sweden)

    Malena Monteverde-Verdenelli

    2016-07-01

    Full Text Available En general, la medición de prevalencias de discapacidades a nivel de población o de grandes muestras se basa en auto-reportes. Resulta de interés evaluar en qué medida dichos auto-reportes permiten realizar comparaciones entre grupos de población. El objetivo del presente trabajo es medir, comparar y analizar la consistencia de las comparaciones de la prevalencia de discapacidades en actividades de la vida diaria (AVD entre poblaciones de América Latina. El análisis incluye las poblaciones de Buenos Aires, Santiago de Chile, Sao Pablo, Ciudad de México, Montevideo y La Habana. Para evaluar la consistencia de las comparaciones basadas en auto-reportes, se estiman prevalencias de discapacidades en AVD y prevalencias de enfermedades crónicas relacionadas con la discapacidad. Luego se comparan los patrones observados en países con ambas condiciones. Las poblaciones de 60 años y más de Buenos Aires y Montevideo reportan menores dificultades para la realización de AVD y menores prevalencias de condiciones crónicas discapacitantes como diabetes, enfermedades pulmonares, enfermedades cerebrovasculares y problemas cognitivos. Sin bien ello sugiere que al menos parte de las diferencias de auto-reporte de discapacidades podrían deberse a diferencias de morbilidad, no se descarta la existencia de efectos por diferencias en factores contextuales o en las propensiones a reportar discapacidades, entre otros. En este sentido, sería de utilidad llevar a cabo estudios ad-hoc que permitan medir simultáneamente diagnósticos y auto-reportes, la implementar instrumentos como viñetas e incluir información sobre factores contextuales (al menos para sub-muestras, y así poder evaluar la existencia de sesgos sistemáticos y la importancia de factores contextuales en los auto-reportes de discapacidades.

  19. ESTIMACIÓN DE CALIDAD DE OBJETOS DE APRENDIZAJE EN REPOSITORIOS DE RECURSOS EDUCATIVOS ABIERTOS BASADA EN LAS INTERACCIONES DE LOS ESTUDIANTES

    Directory of Open Access Journals (Sweden)

    Aldo Gordillo Méndez

    2018-01-01

    Full Text Available Los recursos educativos abiertos se han erigido como uno de los pilares fundamentales de la educación abierta. Una de las principales barreras que está obstaculizando su uso y adopción es la carencia de mecanismos de control de calidad efectivos y sostenibles en los repositorios. Estrategias de evaluación como la revisión por pares no han resultado lo su®cientemente escalables para afrontar el ritmo de creación de materiales abiertos por parte de la comunidad. El presente estudio muestra una nueva estrategia basada en analíticas de aprendizaje para estimar la calidad de los objetos de aprendizaje en base a las interacciones que los estudiantes tienen con ellos en entornos abiertos. Se analizaron 146.291 sesiones de interacción de estudiantes con 256 objetos de aprendizaje distribuidos a través de un repositorio abierto. Un total de 11 interacciones estudiante-objeto de aprendizaje fueron consi- deradas en el estudio. La calidad de los recursos fue medida empleando el instrumento estándar de evaluación LORI (Learning Object Review Instru- ment. Para estudiar las relaciones entre las interacciones de los estudiantes con los objetos de aprendizaje y la calidad de los mismos y para construir una métrica de predicción se utilizaron análisis de regresión lineal. Los resulta- dos muestran que existe relación entre las interacciones y la calidad, y que es posible estimar con un error moderado la calidad de los objetos de apren- dizaje en base a las interacciones que los estudiantes tienen con ellos. Los resultados obtenidos señalan que la analítica de aprendizaje propuesta puede ser utilizada en repositorios de objetos de aprendizaje abiertos para detectar automáticamente recursos con ̄ictivos o de baja calidad.

  20. Ecosistema Emprendedor para las Empresas de Base Tecnológica: Visión Basada en los Recursos (Entrepreneurial ecosystem for the TBFs: a resource-based view

    Directory of Open Access Journals (Sweden)

    Antonia Mercedes García Cabrera

    2012-12-01

    Full Text Available Partiendo de la Teoría basada en los recursos , en el presente trabajo se analizan los diferentes activos tangibles e intangibles que afectan la creación de EBT en un territorio particular. La investigación, centrada en la búsqueda de explicaciones causales, utiliza información de carácter secundario para hallar los principales recursos críticos necesarios en cada una de las fases a través de las que evoluciona el ecosistema emprendedor en el que proliferan estas empresas. Como resultado, se aporta un modelo en el que los recursos humanos, sociales, tecnológicos, financieros y físicos, así como su interacción, constituyen los activos críticos que explican la creación diferencial de EBT en un territorio. ABSTRACT This article analyzes different tangible and intangible assets that affect the creation of EBTs in a particular territory, starting from the resource based theory. The research, centered in a search for causal explanations, uses secondary information to find the main critical resources necessary in each evolutionary phase that the entrepreneurial eco system undergoes. As a result, a model involving human, social, technological, financial and physical resources, as well as their interaction, that comprises the critical assets explaining the creation of EBTs in a territory, is presented.