Ciencias básicas
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Recent Submissions
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Pollinia as "pseudopalpi" on Archisepsis in Costa Rica: accidental or opportunistic?
(2022-11)Male sepsids carrying pollinia as pseudopalpi were observed at three separate bait stations (small dung baits set out to attract other flies) about 500m apart along a side trail in the Peninsula Sector of Parque Nacional ... -
Exact phase space functional for two-body systems
(2010-11-21)The determination of the two-body density functional from its one-body density is achieved for Moshinsky's harmonium model, using a phase-space formulation, thereby resolving its phase dilemma. The corresponding sign rules ... -
Quantum gauge models without classical Higgs mechanism
(2010-09-15)We examine the status of massive gauge theories, such as those usually obtained by spontaneous symmetry breakdown, from the viewpoint of causal (Epstein-Glaser) renormalization. The BRST formulation of gauge invariance in ... -
Condensación de Cetonas Alifáticas con la Fenantrenoquinona en Hidróxido de Amonio
(1971)A study on the synthesis and structure of the products of condensation of phenanthrenequinone with acetone and methyl-ethyl-ketone in presence of ammonia was made. The structures were established by spectroscopic methods. ... -
Residuos de insecticidas organofosforados en repollo (Brassica oleracea var. capitata)
(1976)Pesticide residues from organophosphorus insecticides were determined colorimetrically in cabbage (Brassica oleracea var. capitata) var. "Golden Acre", ready for shipment to the market. The cabbage studied came from Palmira ... -
Kinetik und Thermodynamik einer thermischen Umlagerung in der λ5-Phosphorinreihe. Die Umlagerung von 1-Acetoxy-λ5-phosphorin* in 6-Acetyl-1-oxo-1λ5-phospha-2,,4-cyclohexadien
(1974-03)Beim Erhitzen von 1-Acetoxy-1-isopropoxy-2,4,6-triphenyl-λ5-phosphorin (1c) in 1,4-Dioxan entsteht 6c-Acetyl-1-isopropoxy-1r-oxo-2,4,6-triphenyl-1λ5-phospha-2,4-cyclohexadien (2c), das durch säurekatalysierte Epimerisierung ... -
Thermische und Photochemische Umlagerungen an λ5-Phosphorinen
(1973-05-22)Durch Zweistufenoxydation der λ5-Phosphorine 4 und 5 wurden die neuen λ5-Phosphorine 7, 21 und 23 - 28 synthetisiert. Das 2,4-Diphenyl-6-t-butyl- λ5-phosphorin (5), das 2,4-Diphenyl-6-t-butyl-pyrylium-tetrafluoroborat (2) ... -
Efecto de la disponibilidad de refugios en la distribución espacial del murciélago de ventosas, Thyroptera tricolor
(2023)La disponibilidad de recursos puede influenciar los patrones de uso del espacio y comportamiento de las especies. Para especies especialistas en un recurso, la distribución y abundancia de este puede llevar a la competencia ... -
Caracterización molecular de bacterias simbióticas provenientes de especies forestales leguminosas y evaluación de la respuesta de inoculación
(2023-05-26)La diversidad de bacterias fijadoras de nitrógeno asociada con especies forestales tropicales ha sido relativamente poco estudiada. En este estudio se aislaron bacterias simbiontes en nódulos de ocho especies forestales ... -
Agresividad y competencia por refugios en el murciélago Kerivoula hardwickii
(2022)En la competencia por recursos, generalmente se ha pensado que los animales con mayor tamaño y masa corporal tienen más probabilidades de ganar batallas. Sin embargo, recientemente se ha descubierto que las diferencias de ... -
Aristolochia hondurensis (Aristolochiaceae), a new species from Honduras
(2023-02-23)Aristolochia hondurensis, a new species of Aristolochia series Hexandrae subseries Hexandrae, endemic to Honduras, is described and illustrated. It is a species morphologically similar to Aristolochia anguicida, from which ... -
Converging science and literature cultures: learning physics via The Little Prince novella
(2018)Primary level education follows a pedagogy model where literature and science have been historically separated. Natural children processes are disrupted, as learning based on play curiosity is completely transformed by a ... -
Sensitivity of precipitation and atmospheric low-level circulation patterns to domain size and choice of parameterization schemes in RegCM4.4 over Central America
(2022-12)The sensitivity of regional climate model simulations to domain size and position is becoming increasingly important for generating reliable climate scenarios. In this study, the Central America CORDEX domain (CCA) at 50 ... -
Probability of induced extreme precipitation events in Central America due to tropical cyclone positions in the surrounding oceans
(2022-12-29)The preparedness of national and local authorities for extreme hydrometeorological events could alleviate the impacts in many socioeconomical sectors. A statistical tool for the prediction or assessment of extreme ... -
Assessing dengue fever risk in Costa Rica by using climate variables and machine learning techniques
(2023-02-13)Dengue fever is a vector-borne disease affecting millions yearly, mostly in tropical and subtropical countries. Driven mainly by social and environmental factors, dengue incidence and geographical expansion have increased ... -
Demystifying Orchid Pollination
(2023)Demystifying Orchid Pollination explores the fascinating natural history of orchids and the extraordinary means by which they reproduce. Author Adam P. Karremans reveals their hidden secrets, from the cruel obsession of ... -
Beyond the various contrivances by which orchids are pollinated: global patterns in orchid pollination biology
(2023)Orchidaceae show remarkable diversity in pollination strategies, but how these strategies vary globally is not entirely clear. To identify regions and taxa that are data-rich and lend themselves to rigorous analyses or are ... -
Two new cauliflorous species of Aristolochia subseries Anthocaulicae (Aristolochiaceae) from southern Central America
(2022)Two new cauliflorous species of Aristolochia subseries Anthocaulicae from southern Central America are described and illustrated. Aristolochia guanacastensis from northwestern Costa Rica resembles A. ruiziana, from which ... -
Evaluación de la Dosis Efectiva por la Incorporación de Flúor 18 en el Personal Ocupacionalmente Expuesto del Laboratorio Ciclotrón-PET/CT
(2023)La incorporación de radionúclidos es uno de los riesgos asociados a las prácticas de producción y manipulación de radiofármacos, por lo que, esta investigación tiene como objetivo general desarrollar una metodología para ... -
Evaluación de prácticas agrícolas sobre la comunidad de aves en un paisaje cafetalero con distintos tipos de manejo
(2023)Entre los varios métodos de producción agrícola extensiva existentes, se producen distintos impactos ambientales y sociales. Uno de los más grandes constituye la pérdida de hábitat para la vida silvestre. La agricultura ...
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