Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14837

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Desarrollo larval de cichlasoma sp (pisces : cichlidae) cultivados en laboratorio
(Universidad Nacional de Costa Rica, 1988-09-29) Murillo Sánchez, Roger E.
Se describe el desarrollo embrionario y larvario de Cichlasoma sp. tras la fecundación natural de los huevos. Los huevos se obtuvieron de adultos capturados en la Hacienda Santiago, Heredia, Costa Rica. Se mantuvieron en acuarios a 24,5 ± 10,2 °C, 6,4 ppm de O₂ y un fotoperiodo de 12:12 horas. Los huevos son oblongos, de 2,1 mm de longitud y 1,6 mm de ancho. La eclosión ocurre entre las 48 y 52 horas posteriores a la fecundación. Al eclosionar, las larvas miden 4,6 ± 0,1 mm de longitud. El alimento se consume al noveno día después de la eclosión; la alimentación comienza al séptimo día. La fase juvenil comienza con una longitud de 15,5 ± 0,6 mm. La secuencia de desarrollo de las aletas es: pectorales, caudal, anal y pélvicas.
FRUTA DORADA (VIROLA KOSCHNYI WARB.) UNA ESPECIE PROMISORIA PARA LA REFORESTACION EN EL BOSQUE HUMEDO Y MUY HUMEDO TROPICAL
(Universidad Nacional de Costa Rica, 1990-04-30) Eladio, Chaves S; Rodríguez, Johnny; González, Eugenio
We present forestry experiences on the establishment and management of Virola koschyni Warb (Myristicaceae), a tree species from the tropical wet forest. In the nursery, plants were successfully produced by keeping soil brick and pruning the roots. Data from permanent thinning and yield plots showed that after six years, Virola koschyni reached an average 13.3 cm of DBH and 10.5 m of height. In addition, we include ecological and silvicultural information on this little known species.
NUEVAS ESPECIES DE INGA MILLER (MIMOSACEAE) PARA MESOAMERICA
(Universidad Nacional de Costa Rica, 1990-07-16) Zamora V, Nelson.
A partir de un estudio de las Mimosaceae de Costa Rica, se describen aquí nueve especies de Inga nuevas para la ciencia. Se incluye su distribución y afinidades taxonómicas.
Biological Activity of Extracts of Trichilia Species and the Limonoid Hirtin Against Lepidopteran Larvae
(Elsevier Science Ltd, 1994) Xie, Y. S.; Isman, M. B.; Gunning, P.; Mackinnon, S.; Arnason, J. T.; Taylor, D. R.; Sánchez. V, P.; Hasbun, C; Towers, G. H. N.
Crude extracts of several Trichilia species (Meliaceae) were evaluated for their behavioral and physiological effects on the polyphagous lepidopterans Peridroma saucia and Spodoptera litura. A majority of extracts of nine Trichilia species, collected primarily from Costa Rica, significantly deter larval growth of P. saucia. Extracts of wood and bark are generally more active than those of foliage. Effects of various tissue extracts from T. connaroides on P. saucia and S. litura were comparatively studied. Extracts of bark, the most active tissue compared to those of wood, seed, exocarp and leaf, reduced larval growth of P. saucia and S. litura by 50% at dietary concentrations of 29.1 and 185.1 ppm, respectively. The limonoid hirtin, a constituent of Trichilia hirta, significantly inhibited larval growth of P. saucia in a dose-dependent manner, with a dietary EC50 (effective concentration to inhibit growth by 50% relative to controls) of 13.0 ppm. Hirtin and various extracts from T. connaroides significantly reduced larval growth and consumption rates, as well as dietary utilization, indicating that these substances possess both behavioral effects and post-ingestive toxicity.
Resistance and resilience in a directly regenerating rainforest: Nicaraguan trees of the Vochysiaceae after Hurricane Joan
(Elsevier, 1994-10) Boucher, Douglas H.; Vandermeer, John H.; Mallona, María Antonia; Zamora, Nelson; Perfecto, Ivette
Two trees of the family Vochysiaceae, Vochysiaferruginea and Qualea paraensis, were abundant in a Nicaraguan rainforest which was heavily damaged by Hurricane Joan in 1988, and both had recovered their previous densities by 1993. However, their regeneration followed quite different paths. Vochysia suffered complete mortality of adult trees in the hurricane, but rapid growth and high survivorship of its abundant seedlings and sprouts of saplings, restored its population density (though not yet its mean diameter at breast height) and indeed led to spatial expansion. Qualea, however, showed 100% survival of trees during the hurricane but substantial mortality in the following years. Although seedlings and sprouts of Qualea are quite rare, ingrowth is sufficient to maintain the population so far. However, vine growth on Qualea (unlike Vochysia) is substantial. These two species are thus contrasting elements of the 'direct regeneration' which has been observed in this rainforest. The Vochysia pattern of death and recovery can be described as 'resilience', while the Qualea pattern of survival can be called 'resistance'. The regenerating Vochysia population is mostly seedlings and saplings, while that of Qualea is mostly adult trees. Depending on the pattern of regeneration, different management strategies will be appropriate for maintaining tree species subject to natural disturbances such as hurricanes and/or artificial ones such as logging.
Altitudinal zonation of montane Quercus forests along two transects in Chirripó National Park, Costa Rica
(Springer, 1995-08) Kappelle, Maarten; Van Uffelen, Jan-Gerrit; Cleef, Antoine
Abiotic and vegetation data were collected along two altitudinal transects through mature montane Quercus forests on the Pacific and Atlantic slopes of Costa Rica's Chirripó Massif. Between 2000 and 3200 m asl twenty-four 0.05 ha forest plots were selected at altitudinal intervals of 100 m, and eight soil profiles were described at intervals of 200 m. A TWINSPAN classification aided in the determination of eight zonal forest communities on the basis of their floristic composition. They are grouped in two sets of four: (i) the palm-rich lauraceous-fagaceous Lower Montane Mollinedia-Quercus Forests (2000-2600 m asl) and (ii) the bamboo-rich myrsinaceous-fagaceous Upper Montane Schefflera-Quercus Forests (2500-3200 m asl), respectively. Vegetation changes seem correlated with two major climatic gradients: (i) a temperature gradient (altitude), and (ii) a moisture gradient (wet Atlantic vs. moist Pacific slope). Most soils are Andepts, and residual, colluvial or derived from volcanic material. Humus layers are thicker on the wetter Atlantic slope. A total of 431 vascular plant species consisted of 86 pteridophytes, 1 gymnosperm, 296 dicots and 48 monocots. Species richness, canopy height and stem diameter decrease with increasing altitude, while the canopy surface becomes more flattend. A comparison with other studies shows that Chirripó's montane Quercus forests fit within the environmental ranges known from altitudinal zonations elsewhere in the Tropics. © 1995 Kluwer Academic Publishers.
Screening of Costa Rican Trichilia species for biological activity against the larvae of Spodoptera litura (Lepidoptera : Noctuidae)
(Elsevier Science Ltd, 2001-04) Wheeler, Deborah A.; Isman, Murray B.; Sanchez Vindas, Pablo; Arnason, John T.
Crude methanolic extracts made from the twigs of 39 plant samples from six species of Trichilia collected in Costa Rica, were incorporated into arti®cial diet and fed to neonate Spodoptera litura larvae. All six plant species tested signi®cantly reduced larval growth after 7 and 10 days. The most active species was T. americana, reducing growth, on average, to 3.9% of control at 1000 ppm fresh weight. The least active, on average, was T. glabra. A twig extract of T. americana proved to be more active than wood, bark or leaf extracts, with the twigextract reducing growth of S. litura larvae by 50% (EC50) at a dietary concentration of 17.2 ppm. When T. americana wood extract was incorporated into arti®cial diet (10, 25, 50 and 75 ppm) and fed to S. litura larvae throughout larval development, growth was slowed and the nal weight of pupae and adults was reduced. At higher extract concentrations (50 and 75 ppm) larvae entered one or two supernumerary instars before pupation occurred. This was shown to be due to both starvation and to post-ingestive activity of the extract.
Anti-inflammatory and antinociceptive activities of Loasa speciosa in rats and mice
(Elsevier, 2003) Badilla Baltodano, Beatriz; Arias, A. Y.; Arias, M.; Mora, G. A.; Poveda Alvarez, Luis
In the range of doses of 250–500 mgykg (given i.p.) the aqueous extract of Loasa speciosa leaves showed an inhibitory effect on leukocyte migration, and a reduction on the pleural exudate, as well as dose-dependent anti-inflammatory and peripheral antinociceptive activities.
Inhibition of human pathogenic fungi by ethnobotanically selected plant extracts
(Deutschsprachige Mykologische Gesellschaft, 2003-02-14) Ficker, Christine E.; Arnason, J. T.; Sanchez Vindas, Pablo; Álvarez, L. P.; akpagana, koffi; Gbéassor, M.; De Souza, C.; Smith, M. L.
In this study, 36 extracts derived from 29 plant species selected using an ethnobotanical approach were tested for antifungal activity against a taxonomically diverse group of 13 human pathogenic fungi. We compared the inhibitory characteristics of these plant extracts with those of the commonly used antifungals, amphotericin B and ketoconazole, and the plant-derived antifungal, berberine. Several plant extracts, notably those from Zingiber officinale (ginger) and Juglans cinerea (butternut), had pronounced antifungal activity against a wide variety of fungi, including strains that were highly resistant to amphotericin B and ketoconazole. Further exploration of Z. officinale as an antifungal is warranted as this species is generally regarded as safe for human consumption.
Una nueva especie de Eugenia L. (Myrtaceae) de las selvas húmedas costarricenses
(Universidad de Costa Rica., 2004) Sánchez Vindas, Pablo
Se describe una nueva especie de Eugenia (Myrtaceae) de las veinte caribe de Costa Rica. Se distingue por las hojas con doble nervio marginal y los frutos acostillados y muy reticulado.
Heartwood, sapwood and bark contents of bombacopsis quinata in Costa Rica
(Instituto de Investigación Forestal de Malasia, 2004-07) Pérez, D.; Kanninen, M.; Matamoros, F.; Fonseca, W.; Chaves, E.
The Costa Rican government has promoted the establishment of high yielding plantations, expecting to produce high quality timber. Nowadays the management of some species have been uncertain, since wood quality and yield are becoming lower than expected. Heartwood content is a determinant characteristic for Bombacopsis quinata, a widely appreciated species in the country. The aim of this study was to evaluate the heartwood, sapwood and bark content of young and advanced aged B. quinata trees. The research was based on the hypothesis that heartwood content increases with increasing age. By means of stem analysis, the heartwood, sapwood, and bark volume was measured on trees of different ages (10 to 27 years). The highest heartwood proportion found in B. quinata was 13.6%, and the lowest 0.1%. The sapwood ranged between 70.0 and 87.2% while the bark, from 9.4 to 23% of the total stem volume. No clear differences in heartwood content could be observed between trees of similar age from dry and wet zones. Rotation periods for B. quinata in Costa Rica should be extended to produce high quality timber with increased heartwood content.
A regression analysis of Q'eqchi' Maya medicinal plants from southern Belize
(Universidad Nacional, Costa Rica, 2006) Sánchez Vindas, Pablo
Amiguet, V.T., Department of Biology, University of Ottawa, P.O. Box 450, Ottawa, Ont. K1N 6N5, Canada; Arnason, J.T., Department of Biology, University of Ottawa, P.O. Box 450, Ottawa, Ont. K1N 6N5, Canada; Maquin, P., Belize Indigenous Training Institute, Punta Gorda, Toledo District, Belize; Cal, V., Belize Indigenous Training Institute, Punta Gorda, Toledo District, Belize; Sänchez-Vindas, P., Herbario Juvenal, Universidad Nacional, Heredia, Costa Rica; Alvarez, L.P., Herbario Juvenal, Universidad Nacional, Heredia, Costa Rica
Cuatro compuestos nuevos del extracto no polar de la planta Amyris brenesii (Rutaceae) de Costa Rica
(Universidad de Costa Rica., 2008) Chavarría, Max; Castro, Victor; Poveda, Luis; Murillo, Renato
El estudio fitoquímico de las partes aéreas de Amyris brenesii (Rutaceae) recolectadas en Río Cuarto, Grecia, Alajuela (Costa Rica) mostró la presencia de cuatro nuevos compuestos: la 6-hidroxi-6-O-(3-hidroximetil-3-metilalil)- angelicina 1, el 6-(N-acetil-etanamin) -2,2-dimetil-2Hcromeno 2, el lignano 2,5-deshidrohinokinina 3 y la N-acetil-O-(geranil)-tiramina 4. Adicionalmente se aislaron los lignanos hinokinina 5, y justicidina E 6, las cumarinas escopoletina 7 y marmesina 8, el ácido 24-moretenoico 9 y el O-(3,3-dimetilalil)-halfordinol 10. Las separaciones se llevaron a cabo mediante la aplicación de técnicas cromatográficas y la elucidación de las estructuras se realizó con la ayuda de técnicas espectroscópicas de Resonancia Magnética Nuclear (RMN) de una y dos dimensiones.
Chemical composition of bulk precipitation in the metropolitan area of Costa Rica, Central America
(Universidad Nacional de Costa Rica, 2009-05-04) Herrera, M. J.; Rodríguez, R. S.; Báez, A. P.
Tracemetals and inorganic ionswere measured in bulk precipitation sampled at eleven sites in the metropolitan area of Costa Rica. The ions were analyzed by ion chromatography, and the trace metals by atomic absorption spectrometer with a graphite furnace attachment. The results indicated that Na+ and SO4 2− were the most abundant ions, and of the metals, that Al and Fe had the highest concentrations. Spearman's correlation applied to all data showed a high correlation among SO4 2−, NO3− and NH4+, indicating a common anthropogenic origin. In addition, the correlation found between Na+, K+ and Cl−indicated a sea aerosol contribution. High positive correlations between tracemetalswere found for Al–Mn, Ni–Mn, Ni–Al, Cu–Ni, Pb–Cu, Pb–Ni and Pb–Mn.
Q’eqchi’ Maya healers’ traditional knowledge in prioritizing conservation of medicinal plants: culturally relative conservation in sustaining traditional holistic health promotion
(Springer Nature, 2009-07-30) Pesek, Todd; Abramiuk, Marc; Fini, Nick; Otarola Rojas, Marco; Collins, Sean; Cal, Víctor; Sánchez Vindas, Pablo; Poveda Álvarez, Luis; Arnason, John T.
This ethnobotanical study in the spirit of transdisciplinarity, and in collaboration with Q’eqchi’ Maya traditional healers, compares traditional Q’eqchi’ Maya ecosystem constructs or environmental zones with scientific ecosystems. To determine which categorization method better accommodates Q’eqchi’ Maya medicinal plant diversity, we analized 26 transects representing 160 medicinal plant occurrences. Our transect array encompasses a representative sampling of Q’eqchi’ Maya medicinal plant repertoire with use values broadly distributed over 17 usage categories. With a cumulative frequency of 2,235 medicinal plants through ecological zones, we conducted one-way ANOVA on the mean number of medicinal plant species identified in transects of the two conceptual schemes being contested. Our analysis reveals the Q’eqchi Maya environmental zones are the most salient. That is, knowledge of the Q’eqchi’ Maya environmental zones improves one’s ability to predict whether there will be a high or low abundance of Q’eqchi’ Maya medicinal plant species in a particular region, whereas knowledge of scientific ecosystems does not accomplish this feat as well. This is a notable finding as it suggests that if indeed Q’eqchi’ Maya medicinal plant diversity is better accounted for by the zones as envisioned by the Q’eqchi’ Maya, then it should be this mode of conceptualization that should be adopted by scientists and conservationists when trying to locate and protect regional Q’eqchi’ Maya medicinal plant diversity. These efforts serve as a model internationally in the conservation of medicinal plant biodiversity supportive of culturally relative holistic health promotion.
Sulfate, nitrate and chloride in PM10 in the city of San Jose, Costa Rica: 2004-2006
(Escuela de Ciencias Ambientales, 2009-11-23) Herrera, M. J.; Rojas, M, J. F.; Rodríguez, R. S.; García-Martínez, R.
Se realizó la determinación de los niveles de PM10 en dos sitios de la ciudad de San José (Catedral Metropolitana y Junta de Educación) durante un período de 2.5 años (abril 2004–octubre 2006) obteniendo una mediana de 39 ± 8 y 27 ± 8 µg m–3, respectivamente. En forma adicional, se midieron las concentraciones de SO42–, NO3– y Cl– registrando promedios que no son significativamente diferentes para ambos sitios de medición. Al aplicar el análisis de componentes principales a los datos, se obtuvieron dos factores que explican un 65% del total de la varianza. El factor PC1 incluye a la concentración de Cl– y la velocidad del viento sugiriendo la posible contribución marina de este anión. El factor PC2 muestra una relación entre las concentraciones de SO42–, NO3– y PM10, demostrando su origen antropogénico.
Concentration of PM10 in the Metropolitan Area of Costa Rica, Central America: chemical composition and potential sources
(Universidad Nacional, Costa Rica, 2010) Herrera-Murillo, Jorge; Rojas Marín, José Félix; Rodríguez Román, Susana; Báez Pedrajo, Armando
Measurements of metals and inorganic ions were carried out on PM10. Sampling was made in five sites distributed in San José, Heredia and Belén cities. Samples were collected using Thermo Andersen PM10 high volume samplers with glass fiber and quartz filters. The ions SO4 2- , NO3- , Cl- , F- , PO43- , NH4 + , K+ , Na+ , Ca2+, Mg2+ were analyzed by ion chromatography and in the case of metals V, Cu, Cr, Pb, Ni, Mn, Fe, Al using an atomic absorption spectrometer with a graphite furnace attachment. The results indicated that SO42- was the most abundant ion, and with respect to metals, Al and Fe had the highest concentration. Spearman correlation, applied to all data, showed a high correlation between SO42- , NO3- and NH4+ indicating a common anthropogenic origin. From the metal species that were assessed only Pb and Cu presented enrichment factors higher than 10, indicating an anthropogenic contribution. Particles collected in the industrial zone of Belén showed the highest level of acidity and metal content.
Detailed structure of the tropical upper troposphere and lower stratosphere as revealed by balloon sonde observations of water vapor, ozone, temperature, and winds during the NASA TCSP and TC4 campaigns
(Advancing Earth and Space Sciences, 2010-09-21) Selkirk, Henry B.; Vömel, Holger; Valverde Canossa, Jéssica María; Pfister, Leonhard; Diaz, Jorge Andrés; Fernández, Walter; Amador, Jorge; Stolz, Werner; Peng, Grace S.
We report on balloon sonde measurements of water vapor and ozone using the cryogenic frost point hygrometer and electrochemical concentration cell ozonesondes made at Alajuela, Costa Rica (10.0°N, 84.2°W) during two NASA airborne campaigns: the Tropical Convective Systems and Processes (TCSP) mission in July 2005 and the Tropical Composition, Clouds, and Climate Coupling Experiment (TC4), July–August 2007. In both campaigns we found an upper troposphere that was frequently supersaturated but no evidence that deep convection had reached the tropopause. The balloon sondes were complemented by campaigns of 4 times daily high‐resolution radiosondes from mid‐June through mid‐August in both years. The radiosonde data reveal vertically propagating equatorial waves that caused a large increase in the variability of temperature in the tropical tropopause layer (TTL). These waves episodically produced cold point tropopauses (CPTs) above 18 km, yet in neither campaign was saturation observed above ∼380 K or 17 km. The averages of the water vapor minima below this level were 5.2 ppmv in TCSP and 4.8 ppmv in TC4, and the individual profile minima all lay at or above ∼360 K. The average minima in this 360–380 K layer provide a better estimate of the effective stratospheric entry value than the average mixing ratio at the CPT. We refer to this upper portion of the TTL as the tropopause saturation layer and consider it to be the locus of the final dehydration of nascent stratospheric air. As such, it is the local equivalent to the tape head of the water vapor tape recorder.
Hypoglycemic and antihyperglycemic effect of Witheringia solanacea in normal and alloxan-induced hyperglycemic rats
(Elsevier, 2011) Herrera, Cristina; García Barrantes, Pedro M.; Binns, Franklin; Vargas, Marianela; Poveda, Luis Jorge; Badilla, Sandra
Witheringia solanacea is a small shrub that belongs to the Solanaceae family. The plant is used as an antidiabetic in Costa Rican herbal medicine. The aim of this study was to evaluate the hypoglycemic and antihyperglycemic activity of the aqueous extract of W. solanacea leaves in rodent models. About the materials and methods, a crude extract of W. solanacea leaves was prepared in boiling water and the aqueous filtrate was lyophilized. A single oral dose of 250, 500 and 1000 mg/kg of the extract was evaluated for hypoglycemic activity in a glucose tolerance test in normal rats and for antihyperglycemic activity in alloxan-induced (140 mg/kg) diabetic rats. The blood glucose level was determined at different times by the glucose oxidase method. It Result in a Dosage of 500 and 1000 mg/kg of the extract significantly decreased (p < 0.05) blood glucose levels in the glucose tolerance test in normal rats after 1 h, there was no significant difference observed at 250 mg/kg. Dose of 500 mg/kg of the extract significantly reduced (p < 0.05) blood glucose levels in alloxan induced hyperglycemic rats at 4 and 5 h. In Conclusion, in the present study, the hypoglycemic and antihyperglycemic potential of the W. solanacea was demonstrated in rats. These results give support to the traditional use of W. solanacea as antidiabetic herbal medicine.
Evolución de la contaminación del aire en la ciudad de San José, Costa Rica: 2004-2008
(Tecnología en Marcha, 2011) Herrera Murillo Jorge; Rodríguez Román Susana; Rojas Marín José Félix
Se evaluaron los promedios mensuales de dos contaminantes criterio, medidos en la ciudad de San José, durante el periodo 2004-2008: partículas PM10 y dióxido de nitrógeno. Al analizar las tendencias, se puede observar que en el caso de las partículas, la tasa de crecimiento anual se encuentra por debajo del 3%, o negativa en el caso de la Catedral Metropolitana, esto puede deberse al efecto positivo por la revisión técnica vehicular y la mejora en la calidad de los combustibles. Sin embargo, en el caso del dióxido de nitrógeno, se presentan tasas de crecimiento anual cercanas al 10% para zonas comerciales e industriales de la ciudad.

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