Showing papers by "University of Costa Rica published in 1969"

Neutralización del efecto hemorrágico inducido por veneno de Bothrops asper (Serpentes: Viperidae) por extractos de plantas tropicales

Abstract: Organic extracts representing 48 species included in 30 families of Costa Rican tropicalp1ants were evaluated fortheir abiJity to neutralize hemorrhagic acfivity lnduc.ed by the venom of the snake Bothrops aspero Abioassay in mice was used, based ortintraderrnal injection of either venom orvenom-extract mixtiin:l.s followed py the rneasurement ofhemorrhagic areas: Total inhibition of henmrrhage wasobsetved with the ethanolic;ethyl and .aqueous extractsiofBur;w{i simaruba, Clusia torresii, C. pafmana, Croton·4ram, Persea qmericanq, Phoebebrenesu,Pimentadioica, . . Sapindussaponariai Smifax cuculmeco and Virola koschnyi; C:hemicalanalysis of these extracts identified catequines,flavones, anthocyanines

Anti-inflarnmatory activity of Urera baccifera (Urticaceae) in Sprague-Dawley rats

Abstract: On a preliminary test, anti-inflammatory and analgesic dose-related activities on rats were observed for the aqueous fraction of Urera baccifera; this extract was bioassay-guided fractionated and the final aqueous fraction was used according the ethnobotanical use. Carrageenan-induced edema (n=6), was used as an assay in the fractionating process. The anti-inflammatory and antinociceptive properties of the final aqueons fraction were studied using in vivo models. For the anti-inflammatory activity rat paw edema (n=6), pleurisy induced by carrageenan (n=6) and ear edema induced by topical croton oil (n=6) models were used, and tail-fIick test (n=6), abdominal constrictions induced by acetic acid (n=6), and formalin test (n=6), were used for the alltillociceptive activity. The tests perfonned showed an inhibition effeet on !eukocyte rnigration, and a reductioll on pleural exudate, as well as dose-dependant peripheral analgesic activity, al a range of 25-100 mglk:g i.p. The final aqueous fraction contains most of the anti-inflammatory activity of the plant U. baccifera. A possibJe mechanism of action is discussed and based on the results we conclude that this plant has a potential. for both anti-inflammalory and analgesic activity al the c1inical level.

Evaluación agronómica y nutricional del pasto estrella africana ("Cynodon nlemfuensis") en la zona de Monteverde, Puntarenas, Costa Rica. I. Disponibilidad de biomasa y fenología

Abstract: Se evaluo la disponibilidad de biomasa y la fenologia del pasto estrella africana (Cynodon nlemfuensis) a lo largo de 2 anos en muestreos bimensuales, en 4 fincas comerciales de ganado lechero ubicadas en los cantones de Tilaran y Central (latitud 10°20’ N, longitud 84°50’ O, altitud 800 a 1200 msnm) de las provincias de Guanacaste y Puntarenas, respectivamente. La disponibilidad de materia seca pre-pastoreo y la edad fenologica promedio fueron 4484 kg.ha-1. corte-1 y 7,36 hojas verdes por rebrote, respec- tivamente. La composicion botanica promedio de las pasturas fue 86,81% estrella, 2,52% otras gramineas, 1,39% leguminosas, 1,53% malezas y 7,75% material senescente. La disponibilidad de biomasa fue mayor en las fincas con influencia climatica del Oceano Pacifico y su produccion disminuyo en los meses de mayor precipitacion. La edad fenologica del pasto estrella africana se ubica entre 6 y 8 hojas verdes por rebrote, lo cual permite una adecuada recuperacion del pasto, y disminuyo en los meses con excesos de precipitacion.

Producción de biomasa y costos de producción de pastos Estrella Africana ( Cynodon nlemfuensis ), Kikuyo ( Kikuyuocloa clandestina ) y Ryegrass Perenne ( Lolium perenne ) en lecherías de Costa Rica

Abstract: Biomass production costs and dry matterkilogram cost were evaluated in kikuyu grass (Kikuyuocloa clandestina), perennial ryegrass (Lolium perenne) and African stargrass (Cynodon nlemfuensis), along one year, in 8 dairy farms located in Cartago (2), San Jose (2) and Alajuela (4) provinces. Average dry matter yield per cycle was 3395 kg.ha-1 DM for the three grasses. Annual yield is influenced by the regrowth period of each species, with values of 40 170, 38 731 and 28 995 kg.ha-1 DM for African stargrass, kikuyu grass and perennial ryegrass, respectively. Biomass production varies during the year, and the utilization by cattle has a less utilization of these fields during the months of highest yield. Since the stocking rate, the occupational period and the grazing area are not adjusted an the basis of dry matter availability, dairy cattle has a lower utilization rate in the paddocks. Average costs for labor, agricultural inputs and land were (in Costa Rican currency) 72.433, 505.515 and 18.760 colones.ha-1, respectively. Inputs had the highest impact in the costs structure in grazing dairy farms. Costs for dry matter kilogram produced and consumed were 16.6 and 44.4 colones, respectively, for all 3 pastures; the cost of dry matter-kilogram consumed was affected by the rate of utilization in the grazing paddocks. Dairy farms with higher investment in pastures had a higher return in kg.ha-1 milk as well.

Disparity, decimation and the Cambrian "explosion": comparison of early Cambrian and Present faunal communities with emphasis on velvet worms (Onychophora)

Abstract: The controversy about a Cambrian " explosion" of morphological disparity (followed by decimation), eladogenesis and fossilization is of central importanee for the history of life. This p aper revisits the controversy (with emphasis in onychophorans, which inelude emblematic organisms such as Hallucigenia), presents new data about the Chengjiang (Cambrian of China) faunal community and compares it and Ihe Burgess Shale (Cambrian of Canada) with an ecologically similar bul modern tropical marine site where onychophorans are absent, and with a modern neo tropical terrestrial onychophoran community. B i ovolume was estimated from material collected in Costa Rica and morphometric measurements were made on enlarged images of fossils. CaJTlbrian tropical mudflats were characterized by the adaptive radiation of two contrasting groups: the vagile arthropods and the sessile poriferans. Arthropods were later replaced as the dominant benthic laxon by polychaetes. Vagility and the exoskeleton may explain the success of arthropods from the Cambrian to the modern marine and terrestrial communities, both in population and biovolume. Food ecological displacement was apparen t i n the B. Shale, but not in Chengjiang or the terrestrial community. When only hard parts were preserved, marine and terrestrial fossil deposits of tropical origin are even less representative than deposits produced by temperate taxa, Chengjiang being an exception. Nutrient limitations might explain why deposit feeding is less important in terrestrial onychophoran communities, where carnivory, scavenging and omnivory (associated with high motility and life over the substrate) became moreimportant. Fossil morphometry supports the interpretation of "lobopod animal s" as onychophorans, whose abundance in Chengjiang was equal lo their abundance in modern communities. The extinction of marine onychophorans may reflect domination of the infaunal habitat by polychaetes. We conclude tha! ( 1 ) a mature ecological community structure was generalized during the Cambrian, and even biodiversity and equitability indices were surprisingly elose lo modern values; (2) the morphological diversity and geographic distribution of onychophorans indicate a significant pre-Cambrian evolutionary history which does no! support the "explosion" hypothesis; (3) disparity among phyla was not as important as the explosion-decimation model predicIs, bu! in the case of onychophorans, disparity wIlhin the phylum was greater than it is today and its reduction may have been associated with migration into the sedi ment when large predators evolved.

Arcillas identificadas en suelos de Costa Rica a nivel generalizado durante el período 1931-2014: I. historia, metodología de análisis y mineralogía de arcillas en suelos derivados de cenizas volcánicas

Abstract: Se resume la informacion disponible sobre caracterizacion de arcillas en suelos de Costa Rica desde 1931 hasta el presente, descrita en 84 trabajos con 520 observaciones hasta el 2014. La discusion se basa principalmente en la mineralo- gia de arcilla de los horizontes superficiales del suelo, aunque se menciona la mineralogia de los horizontes B cuando esta es diferente a la de los horizontes A de manera relevante. Despues de ubicar los datos puntuales en un mapa del pais, se encontro que algunas areas cuentan con poca o ninguna informacion (peninsula de Nicoya, Zona Norte y region este de la Cordillera de Talamanca). Para el area restante la informacion disponible se agrupo por mineralogias de “arcilla dominante”, identificandose las mineralogias: (1) vidrio-amorfo-halloysitica (Andisoles y otros suelos con caracteristicas andicas); (2) esmectitica y de arcillas interestratificadas (Vertisoles y otros suelos con caracteristicas verticas); (3) oxidos-hidroxidos-oxihidroxidos-caolinita-gibbsita (Alfisoles, Ultisoles y Oxisoles); ademas de una serie importante de mineralogias mixtas en suelos de poco o ningun desarrollo edafico (Entisoles e Inceptisoles). En el texto se discute la genesis (procesos de formacion) de los principales tipos de arcilla del pais, cuando se conto con suficiente informacion para ello.

Evaluación agronómica y nutricional del pasto Estrella africana (Cynodon nlemfuensis) En la zona de Monteverde, Puntarenas, Costa Rica. II. Valor nutricional

Abstract: Se analizo el valor nutricional del pasto estrella africana (Cynodon nlemfuensis) a lo largo de 2 anos en muestreos bimensuales, en 4 fincas comerciales de ganado lechero ubicadas en los cantones de Tilaran y Central (latitud 10°20’ N, longitud 84°50’, altitud 800 a 1200 msnm) de las provincias de Guanacaste y Puntarenas, respectivamente. Las muestras se recolectaron en el aparto siguiente a ser pastoreado y se utilizo una altura de cosecha de 10 cm, para simular el pastoreo que hacen los animales. La composicion nutricional promedio para los 2 anos de evaluacion fue de 23,57% MS, 20,27% PC, 2,67% EE, 10,97% cenizas, 64,21% FDN, 34,95% FDA, 4,06% lignina y 68,02% DIVMS y su contenido energetico para las variables de TND, ED, EM, EN L (3X) y EN G fue 61,37%; 2,71; 2,05; 1,25 y 0,78 Mcal.kg -1 de MS, respectivamente. El valor nutricional del pasto estrella africana vario a lo largo del ano como resultado de la climatologia de la zona de Monteverde, siendo las fincas con influencia de la vertiente del Pacifico las de menor afectacion en la calidad del forraje. El pasto estrella africana mostro un contenido de PC superior a lo reportado para dicha especie y, en general, para pastos tropicales, por lo cual no es limitante para la produccion lactea, y la suplementacion del ganado lechero en la zona debe utilizar fuentes que permitan una utilizacion eficiente del N soluble a nivel ruminal. La rotacion del pasto estrella cada 25 dias debe ser flexible para permitir, en conjunto con programas de fertilizacion, optimizar la productividad de las pasturas y su persistencia.

Incremento de áreas impermeables por cambios de usos de la tierra en la microcuenca del río burío

Abstract: La investigacion se realizo en la microcuenca del rio Burio, Heredia, Costa Rica. Se analizaron tres escenarios de impermeabilizacion de suelos por cambios de uso de la tierra en los anos 1960, 1990 y 2010. Los resultados demostraron una sustitucion de coberturas agroforestales por urbanas; es decir, impermeables. El conjunto de superficies impermeables han alterado la respuesta hidrologica del area de estudio, respecto a la capacidad de la superficie de favorecer o dificultar el escurrimiento directo, la infiltracion o la interceptacion del agua. Esto ha repercutido en aumento de caudales pico en una microcuenca constituida por espacios naturales o poco alterados.

Curvas de absorción de nutrientes en papaya ( Carica papaya L.) cv. “Pococí” en las fases de crecimiento vegetativo, floración e inicio de cosecha

Abstract: In a commercial papaya farm located at Guacimo, Costa Rica, the requirements of nutrients, and the nutrient absorption curves for the Costa Rican high-yielding papaya hybrid “Pococi”, were established. The experiment was carried out in 2010 collecting complete plants, approximately monthly through the phenological cycle of the crop, from transplant until 9 months after wards. It was estimated that the “Pococi” hybrid (1600 plants per hectare) required approximately 354 kg.ha -1 N, 101 kg.ha -1 P 2 O 5 , 498 kg.ha -1 K 2 O, 174 kg.ha -1 CaO, 106 kg.ha -1 MgO and 40 kg.ha -1 S; these required quantities are mostly higher than those that are normally being applied by present fertilization programs in Costa Rica.

Actividad enzimática del suelo -Deshidrogenasa, β-Glucosidasa, Fosfatasa y Ureasa- bajo diferentes cultivos

Abstract: The activity of 4 soil enzymes in farms under different agronomic managements and in different soil types was analyzed The enzymes tested were phosphatase, β-glucosidase, dehydrogenase and urease Soil samples were taken from the first 20 cm in depth, in order to determine the activity of the 4 enzymes and analyze them chemically It was found that Dehydrogenase enzyme activity ranged from 013 to 446 with an average of 117 (μg INTFg - 1 h -1 ); β-glucosidase enzyme ranged from 319 to 2081 with an average of 1081 (μg PNPg -1 h -1 ) Furthermore, phosphatase had values between 4134 and 30436 with an average of 15215 μg PNPg -1 h -1 , while Urease ranged from 125 to 528 with an average of 383 μg N-NH4g -1 h -1 Phosphatase correlated with the percentage of organic matter and carbon in the soil (075 and 076 respectively, p<001); an inverse relationship was found between the activity of this enzyme and the content of available P (-053r, significant at p<010) Urease correlated with phosphatase (r=061 p<005) and with dehydrogenase (r-077 p<001) Multivariate cluster analysis based on the enzymatic activity allowed to make similar groups according to the type of crop, which shows the potential of usage that this property has for undertaking more detailed studies

PRESENCIA DE Colletotrichum acutatum y Colletotrichum gloeosporioides EN HELECHO HOJA DE CUERO, LIMÓN CRIOLLO, PAPAYA, CARAMBOLA Y MANGO EN COSTA RICA Y FLORIDA (ESTADOS UNIDOS)

Abstract: La antracnosis es una enfermedad causada por varias especies del genero Colletotrichum en diferentes hospederos. C. acutatum y C. gloeosporioides son especies morfologicamente similares, que pueden causar sintomas similares en el mismo hospedero. Se colectaron 220 aislamientos de Colletotrichum de muestras con sintomas tipicos de antracnosis en helecho hoja de cuero (Rumohra adiantiformis), limon criollo (Citrus aurantifolia), carambola (Averrhoa carambola), papaya (Carica papaya) y mango (Mangifera indica) en Costa Rica y Florida, Estados Unidos. Los aislamientos se caracterizaron por morfologia de colonia, sensibilidad al benomil, y PCR con los iniciadores especificos para C. acutatum y C. gloeosporioides CaInt2 y Cg/fInt1, respectivamente; tambien se analizo la morfologia de las colonias de ambas especies. De los 85 aislamientos obtenidos de mango, todos los aislamientos de Florida fueron identificados como C. acutatum, mientras que todos los aislamientos de Costa Rica fueron C. gloeosporioides. De los 60 aislamientos de carambola, 3 provenientes de Costa Rica fueron C. acutatum (primer informe) y el resto fueron C. gloeosporioides. Todos los aislamientos de helecho hoja de cuero (25 aislamientos) y de limon criollo (25 aislamientos) se identificaron como C. acutatum. Los demas aislamientos de carambola y mango asi como todos los aislamientos de papaya, se identificaron como C. gloeosporioides. No se encontro diferenciacion de sintomas entre ambas especies sobre los hospederos donde se encontraron.

Organismos de un arrecife-fósil (Oligoceno Superior-Mioccno Inferior),del Caribe de Costa Rica

Abstract: Tbis paper describes tbe fossils, materials and paleoenviromnental conditions found in some outcrops near tbe town of Jesus Maria, Turrialba, Costa Rica. Tbe rock materials (reefal limestone, sandstones and conglomerates) are associated to tbe Punta Pelada Forrnation of Upper Oligocene tu Lower Miocene age. Outcrops are of reduced extent and are unevenly distributed, hence tbey are considered as patch reefs developed by enviromnental energy fluctuations, sea level changes and clastic sedimentation from sources on small islands acting togetber in narrow platforrns. Tbe structural and enviromnental characteristics where fossil communities developed were derived from tbe analysis of 460 samples containing 36 species. Tbe reefs represent low diversity communities comprising four coral species (three of tbem reef builders), 31 mollusks species (21 gastropods: a new species, 14 camivores, three herbivores and three of uncertain feeding habits; 10 bivalves species: five endobentbic and five epibentbic); algae ( at least three groups represented); sea urchins; foraminifers; crabs. Tbe eveuness index is low, mainly regarding tbe Scleractinian corals, where Antiguastrea cellulosa predominates (80% of tbe recognized forrns). Tbe fossil assemblage suggests tbat tbe comm\lnities developed in shallow marine enviromnents (50-80 m deptb), affected by sea level changes, strung marine currents and clastic imput from nearby small islands.

Infection of white rat peritoneal macrophages with Toxoplasma gondii, (Coccidia: Sarcocystidae) after Trypanosoma lewisi (Kinetoplastida: Trypanosomatidae) infection

Abstract: Peritoneal macrophages from Wistar rat's inoculated and non- inoculated with 10 T lewisi trypomastigotes , were cultured and infected with 10 T gondii tachyziodes.

Interpolación de variables de fertilidad de suelo mediante el análisis kriging y su validación

Abstract: The goal of this study was to make and validate interpolated maps of 6 soil fertility variables. The maps were made from the results of Ca, pH, soil acidity, K, P and saturation of soil acidity of 138 soil samples that were taken from 1011 ha at Atirro, Costa Rica. The data were interpolated through ordinary Kriging. The validation was carried out using “field validation” and “cross validation” methods. Correlation coefficient (r) was estimated for both techniques between real and prediction values, and the prediction efficiency (E) as well. Other validation criteria used were the percent success by overlapping between real and estimated values, according to the uncertainty of soil analysis and to the success rate of overlap according to agronomic category. The r values using field validation varied from 0.09 to 0.87; and for cross validation were from 0.52 to 0.84. The variables Ca and pH had the highest prediction efficiency in both validation methods. The overlap criterium due to the uncertainty of analysis was 27 to 93% success, while the overlapping range that was due to agronomic category had 47 to 93% of success. In both cases, pH had the better values of success. It was concluded that the interpolated maps at a regional scale are a useful tool for to carrying out a good prediction on soil fertility properties, although it is important to perform a verification process in order to confirm these approximations, because this could change according to the type of variables.

Densidad crítica de "Meloidogyne exigua" en plantas de almácigo de café variedad caturra

Abstract: The purpose of this study was to evaluate the effect of increasing density of Meloidogyne exigua on the development of nursery plants. Coffee plantlets of the Caturra variety were transplanted into polyethylene bags with 1335 cm3 of disinfected substrate, to establish a trial with a randomized complete block design, with 8 replicates. The treatments applied included initial populations (Pi) of 0; 0,125; 0,25; 0,5; 1; 2; 4; 8; 16; 32 and 64 eggs + J2/cm3 substrate applied one month after transplant. The model y=m+(1-m) ZP-T applied 234 days after transplant to the height, diameter, number of nodes and aerial fresh weight, indicated that the tolerance limit (T) was 0,66; 0,06; 0,13 and 0,88 eggs + J2/cm3, respectively; the relative minimum production (m) was 0,79; 0,79; 0,33 and 0,54 respectively, at Pi equal to or higher than 64 eggs + J2/cm3. The gall index reached its maximum from a Pi of 2; the maximum peak of nematodes on the soil and roots was reached with a Pi between 2 and 4 while, the maximum rate of reproduction rate was 114 with a Pi of 0,125. It was concluded that the critical density was close to zero eggs/cm3 of substrate as initial population, and the nursery plants should develop free of nematodes since, even with a low Pi; it could reach the maximum population in a short time.

VERIFICACIÓN DEL CONTENIDO DE MATERIA SECA COMO INDICADOR DE COSECHA PARA AGUACATE (persea americana) CULTIVAR HASS EN ZONA INTERMEDIA DE PRODUCCIÓN DE LOS SANTOS, COSTA RICA

Abstract: El objetivo de esta investigacion fue estudiar si el contenido de materia seca (CMS) de aguacate podria ser utilizado como un indice de cosecha adecuado en sustitucion del contenido de aceite (CA) en aguacate Hass, cultivado en una zona de altitud intermedia (1750 msnm), en Los Santos, Costa Rica Se marcaron 100 arboles y un total de 2000 flores polinizadas; se evaluaron 35 frutos cada semana, de la semana 31 a la 44 Se encontro que ambos, CA y CMS, mostraron un aumento rapido y significativo despues de la semana 39 (p≥0,05), con un coeficiente de correlacion entre ellos de 0,92 Otros cambios observados simultaneamente, y relacionados con la maduracion de la fruta, fueron el desarrollo del color morado en la cascara (74% de la superficie), la reduccion de la adherencia de la cubierta de la semilla a la pulpa de la fruta, y de esta a la cascara y a la semilla, asi como la disminucion de la firmeza del fruto, de 118 N durante la semana 31 hasta 57 N en la semana 40 y despues de esta Se recomienda usar el 23% de CMS en el fruto de aguacate Hass como un indice de cosecha para el aguacate cultivado a 1750 msnm en la zona de Los Santos, como una alternativa al contenido de aceite de la fruta (CA)

Ausencia de detección de enterovirus en bivalvos Anadara tuberculosa (Bivalvia: Arcidae) p

Abstract: Anadara tuberculosa is one of the most abundant mollusks of cornmercial importance in Costa Rica. Its habitat water is a potential source of fecal and chemical contamination to humans. We wanted to aSSeS enterovirus, 'mainIy poliovirus and hepatitis A virus and chemicals such as sulphates and nitrates in meat and body fluids. Thirteen samples were taken from four sites in Nicoya Gulf, three sites in the Sierpe Terraba mangrove (Pacific of Costa Rica) and from five fish markets in San Jose, the capital of Costa Rica. Sanrpllis were tested for 1) fecal coliforrns (Most Probable Number/100 rul), 2) isolation of enterovirus in cell culture (Hep"2, FrhK-4), 3) cell cytotoxicity in Vero cells and 4) the ability to inactivate 10 ID50% of poliovirus in cell cJllture. The Most Probable Number/100 rulin surrounding water was higher than j:he accepted standard for recreational waters, although the number of fecal coliforrns in meats and body fluids was lower than in the external water. No cytopathogenic agents were isolated, but we found nitrate and sulphate concentrations that exceeded JlUIJd

Nuevos hospederos y registros de ácaros fitófagos para Costa Rica: período 2008-2012

Abstract: Se actualizan las especies de acaros fitofagos identificadas para Costa Rica entre 2008 y 2012. Se proceso el material vegetal provisto por productores, tecnicos, estudiantes e interesados en general, asi como el recolectado por personal del Laboratorio de Acarologia de la Universidad de Costa Rica, y se identifico. Se mencionan 63 nuevas especies en 29 familias de plantas hospedantes, para 5 familias de acaros fitofagos. Tetranychus urticae, familia Tetranychidae, fue la segunda especie en cuanto a numero de hospederos, encontrandose en 12 nuevas plantas. Tambien se hallaron otras especies de la familia, como Eutetranychus banksi, Mononychellus planki, Oligonychus peronis, O.pratensis, O. punicae, O. ununguis, O. yothersi, Paraponychus corderoi, Tetranychus cinnabarinus, T. ludeni, T. mexicanus y 3 especies de este genero que no fueron identificadas. Se registran 4 especies de la familia Tenuipalpidae: Brevipalpus californi cus, B. gliricidiae, B. obovatus y B. phoenicis. Dentro de la familia Tarsonemidae, se informa de Phytonemus pallidus, Polyphagotarsonemus latus, con 15 nuevos registros, especie con mayor aporte en asociacion con plantas para este nuevo periodo; se informa tambien de Steneotarsonemus ananas, asociada con pina. De la familia Eriophyidae, se indica de Abacarus doctus, descrita recientemente como nueva especie para la ciencia y asociada con cana de azucar en el pais y de Calepitrimerus muesebecki, relacionada con aguacate; ademas 2 especies de eriofidos expuestos, no descritas aun. Retracrus johnstoni, familia Phytoptidae, recolectado de Heliconia latispatha, de la familia Heliconiaceae y primer registro de un acaro de este genero asociado con una planta ajena a la familia Arecaceae. Por ultimo, se expone la descripcion del reconocimiento de campo para algunas especies escogidas dentro de las 5 familias estudiadas.

Consumo, calidad nutricional y digestibilidad aparente de morera ( Morus alba ) y pasto estrella ( Cynodon nlemfuensis ) en cabras

Abstract: Se evaluo la calidad, seleccion y digestibilidad aparente en cabras, del consumo de morera y estrella africana ofrecidos de forma fresca y parcialmente deshidratada. El experimento se llevo a cabo en la Estacion Experimental “Alfredo Volio Mata” de la Universidad de Costa Rica. El forraje cosechado fue suministrado a 12 cabras de las razas Saanen, Toggenburg y La Mancha no lactantes y no gestantes, distribuidas en un diseno irrestricto al azar con un arreglo factorial 2x2 y con un peso vivo promedio de 37±5 kg. Los tratamientos experimentales fueron: a) estrella fresca, b) estrella parcialmente deshidratada, c) morera fresca y d) morera parcialmente deshidratada. El forraje se ofrecio a los animales en forma picada. Se observo un consumo promedio de materia seca de: 0,93; 0,76; 1,17 y 1,12 kg.animal-1.dia-1 de MS (±0,09), para los tratamientos estrella fresca, estrella parcialmente deshidratada, morera fresca y morera parcialmente deshidratada, respectivamente. Esto represento 2,62; 2,09; 3,17 y 3,13% (±0,24) del peso vivo. El consumo de proteina cruda fue menor con la estrella parcialmente deshidratada y mayor con la morera fresca (75,2 vs. 135,4 g.animal-1.d-1). El porcentaje de digestibilidad aparente no fue estadisticamente diferente entre tratamientos; presento un promedio de 49,18% para la MS, 59,82% para la PC, 57,83% para la FDN y 55,30% para la FDA. Este estudio demuestra que la especie de forraje influye significativamente sobre el consumo voluntario de materia seca en cabras; sin embargo, el contenido de materia seca en los forrajes utilizados no afecto dicho consumo.

Essential oil of Lepechinia schiedeana (Lamiaceae) from Costa Rica

Abstract: The composition of the essentiai oil isolated by steam distillation from aerial parts of the Costa Rican herb Lepechinia schiedeana (Schlecht) Vatke (Lamiaceae) collected in El Empalme, Costa Rica, was determined by capillary gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GCMS) analyses. Fifty-one components were identified corresponding ca. 93% of the oi!. The major components were -pinene (26.6%), cis -pinocamphone (25.1 %), &-3-carene (6.1 %), trans -pinocamphone (4.0%), camphor (3.8%) and

Evaluación agronómica de trece genotipos de camote ( Ipomoea batatas L)

Abstract: The goal of this study was to determine the agronomic performance of 13 sweet potato genotypes for their cultivation in Costa Rica. Ten were introduced from North Carolina State University’s Micropropagation and Repository Unit, and were grown for the first time in Costa Rica. Two (Exportacion and Zanahoria) were more recent introductions into the country, having been cultivated here for at least 5 years, and the one remaining (Criollo) is the most widely used locally. The field experiment was conducted at the Fabio Baudrit Experiment Station, of the University of Costa Rica, located in Alajuela province. The treatments were laid out in a randomized complete block design, with 13 genotypes and 4 repetitions. The analysis of variance showed significant differences (p=0.0001) among genotypes for all evaluated variables: fresh and dry foliar weight; storage root fresh and dry weight; number of storage roots, storage root weight/plant, dry matter content and yield (t.ha -1 ). The root yield of all genotypes evaluated was higher than that of the local variety Criollo (6 t.ha -1 ) as well as the national average (5 to 7.8 t.ha -1 ), ranging from 12 to 48 t.ha -1 . These results indicate that some varieties are promising for release in Costa Rica, not only because of their good performance in terms of yield, but also due to quality traits such as orange or yellow flesh, associated with high carotene content.

Identificación molecular del hongo Colletotrichum spp ., aislado de banano ( Musa spp ) de altura en la zona de Turrialba y determinación de su sensibilidad a fungicidas poscosecha

Abstract: La antracnosis, causada por el hongo Colletotrichum spp., es una de las principales enfermedades poscosecha que afectan el fruto del banano. En el presente experimento, 25 aislamientos de Colletotrichum spp., obtenidos de frutos de banano provenientes de 5 zonas del canton de Turrialba, Costa Rica, fueron utilizados para caracterizar molecularmente al hongo y evaluar su sensibilidad in vitro a 3 fungicidas poscosecha: tiabendazol, imazalil y miclobutanil. La identificacion molecular de cada uno de los aislamientos se realizo mediante la tecnica PCR con los imprimadores especie-especificos de la region ITS (CgInt/ITS5) y de una region del gen de la s-tubulina (TBCG/ TB5). Para las pruebas de sensibilidad in vitro a los 3 fungicidas, se utilizaron las siguientes concentraciones: 0,1; 1,0; 10,0 y 100,0 μg.ml-1. El analisis de la region ITS y de la region del gen de la β-tubulina, indico que los aislamientos analizados corresponden a la especie Colletotrichum gloeosporioides. En cuanto a las pruebas de sensibilidad in vitro, todos los aislamientos fueron sensibles al tiabendazol, mientras que existe una marcada insensibilidad al imazalil y al miclobutanil.

Ictioplancton en la zona portuaria de Limón, Costa Rica

Abstract: Four sampling stations were set 200-500m off Limon Port, Costa Rica, at an average depth of 20 m. From October 1996 to May 1997 horizontal subsuperficial trawls were done for 12 minutes at a speed of about 2KmIh, with a 1 OOOi.tm plancton neto A total of 28 samples were processed and 104 physieal-chemistry parameter measurements were taken. Average salinity was 30.1 ± 3.7 and dissolved oxygen 6.9 ± 0.6 mg 1-1 reflecting good aeration throughout the sampling period. This suggests good mixture and a highly dynamic hydrography. Temperature showed no drastic variations (28.0 ± 1.7 OC), possibly because of the constant mixing with shallow water. The highest larval counts were for November and early January and inelude families common to reefs and estuaries (BaJistidae, Lutjanidae) and to coastal areas (Centropomidae, Gerreidae, Haemulidae, Carangidae, Engraulidae, Hemiramphidae, and representative Pleuronectiforrnes) existing in a common area.

Arcillas identificadas en suelos de Costa Rica a nivel generalizado durante el período 1931-2014: II. mineralogía de arcillas en suelos con características vérticas y oxídico caoliníticas

Abstract: Se resume la informacion disponible sobre la mineralogia de arcilla de los horizontes superficiales del suelo, aunque se menciona la mineralogia de los horizontes B cuando esta es diferente a la de los horizontes A, de manera relevante, en suelos de Costa Rica desde 1931 hasta el presente. Se enfatiza en la informacion disponible para (1) esmectiticas y de arcillas interestratificadas en Vertisoles y otros suelos con caracteristicas verticas y (2) oxidos-hidroxidos- oxihidroxidos-caolinita-gibbsita en Alfisoles, Ultisoles y Oxisoles. En el texto se discute la genesis (procesos de formacion) de estos grupos dominantes de arcilla cuando se dispone de suficiente informacion.

Citogenética y cito química de pacientes con leucemia en dos hospitales neotropicales

Abstract: A cytogenetic andlor cytochemical study was perforrned in 166 individuals with leukemia or related disorders, in two major Costa Rican hospitals. In thosepatJ.entstreated at an adult's hospital (14 years oId and over),aeute leukemias represented 66% of aH cases. In that hospital the mostfrequent types of disorde , rs were, in decreasing order: ANLL (>Ml), ALL, CML(aIl of them showed the Ph chromosome) and MDS. Inthe cases from a childrens'hospital «14 years(jld) acute leukemias were98%. Amongthem the o

La narrativa costarricense del último tercio de siglo

Abstract: Se aborda el estudio de la narrativa costarricense de las últimas décadas del siglo XX.

Concentración foliar de nutrimentos en plantaciones de teca en la cuenca del Canal de Panamá

Abstract: Foliar nutrient concentration in teak plantations at the Panama Canal watershed. Foliar concentration of macro- and micronutrients in teak plantations at the Panama Canal Watershed was measured on sites classed as high, medium, and low in growth (volume.ha -1 ). For the same purpose, plantations where grouped by age as young (3-4 years), medium (5-6 years) and late (7-8 years). Foliar macro-nutrients concentration followed the order N (1,9%), Ca (1.1%), K (0.7%), S (0.2%) and P (0.1%), while micro-nutrients concentrations decreased in the order Mn (50), Fe (43), Al (36), B (29), Zn (28), Cu (8), and Mo (0.4) mg.kg -1 . The K, P and Fe concentrations were clearly identified as low, while N, Ca, Mg and Mn values can be considered as marginal to slightly low. The Ca, Mg, N, K, Mn, Zn, Fe and Al concentrations varied statistically with plantation age in different ways; foliar concentrations of Ca, Mg, Mn, Fe and Al tend to increase with age, while those of N, K and Zn tend to diminish with age. Concentrations of Ca and Mn in the leaves of trees of sites with high and low growth differed statistically (p<0.01), with Ca values of 1.18% and 0.99%, in the high and low growth categories, respectively, and with Mn values of 41 and 65 mg.kg -1 in sites of high and low growth rates, respectively.

Fenología, producción y valor nutritivo del pasto alpiste ("Phalaris arundinacea") en la zona alta lechera de Costa Rica

Abstract: Se evaluo la produccion de biomasa, el valor nutricional y la fenologia del pasto alpiste (Phalaris arundinacea) con 3 edades de cosecha (49, 70 y 91 dias), a lo largo de ano y medio, en una finca comercial de ganado lechero ubicada en Santa Rosa de Oreamuno, provincia de Cartago. La produccion de biomasa promedio para el pasto alpiste fue 3101 kg.ha-1.corte-1 de MS. La composicion nutricional promedio fue de 17,77% PC, 55,89% FDN, 35,93% FDA, 4,14% lignina y 66,87% DIVMS y su contenido energetico expresado como TND, ED, EM, ENL (3X) y ENG fue 63,07%, 2,76; 2,13; 1,31 y 0,81 Mcal. kg-1 de MS, respectivamente. Se comparo el fraccionamiento de la PC de los pastos estrella africana (Cynodon nlemfuensis) y ryegrass perenne (Lolium perenne) con la del pasto alpiste, con el que las especies de clima templado presentan un aporte principalmente de la fraccion insoluble degradable (B2+B3), mientras el estrella africana lo hace a nivel de la fraccion degradable (A+B1). La edad fenologica promedio del pasto alpiste fue 5,96 hojas verdes por rebrote y su edad debe encontrarse entre 5 y 6 hojas para optimizar su produccion de biomasa y valor nutricional. El pasto alpiste se ha utilizado en diversas fincas de ganado de leche y ha adquirido importancia como una opcion que puede soportar las condiciones climatologicas de las regiones altas de Costa Rica; asimismo, ya hay empresas que importan semilla sexual de dicha especie.

Enfermedad de Lafora y efecto fundador en una pequeña localidad neotropical

Abstract: The Lafora disease is an uncommon genetic condition. Four cases (two families) were detected in Zarcero, a small town in Costa Rica (population under 2000). They belonged 10 two separate consanguineous marriages but both families had common ancestors. The. diagnosis ·of Lafora disease was confrrmed by liver. biopsy' in one of the patients. The ages of onset .were 13, 14, 16 and 17 years. Patients died after four, nine, six and fi ve years of severe progressive physical and mental deterioration, respectively. The gene for Lafora disease arrive to Zarcero from one of its founders. There are no other cases reported from Co.sta Rica: this is an exampie of genetic drift, or more specifically; founder effect.

Antigenic Characteristics of Five Species of Human Bacteroides

Abstract: The antigenic characteristics of five species of Bacteroides were determined by agglutination tests. No cross-reactivity among the species was observed.