• El Uso de Plaguicidas en América Latina: Tendencias e implicaciones ambientales (Memoria Encargada) 

  Constenla Umaña, Manuel Arturo (1988)

  The current demand for pesticides in Latin America exceeds US $ 2000 million in value. Up to 1990, consumption is expected to rise by 7 to 12%. The use of pesticides has been fully accepted in Lati America as a readily ...

• Chapter 6: Founder variations in isolated populations 

  Chavarría Soley, Gabriela; Contreras Rojas, Javier; Raventós Vorst, Henriette (2020)

  Isolated populations, also called population isolates and genetic isolates, present several characteristic features that make them useful in the study of the genetic basis of both Mendelian and complex disorders. The ...

• Evaluación de los efectos de la contaminación atmosférica y el ángulo de exposición sobre la corrosión del acero de bajo carbono y acero galvanizado en la región del Valle Central Occidental (VCO) de Costa Rica 

  Rodríguez Yáñez, Javier E. (2023-05)

  Costa Rica is a country that imports its metallic materials, this makes the evaluation of its corrosion losses of special interest, since they represent an average of 3% of the GDP. In particular, atmospheric corrosion is ...

• Reacciones del 2,2´-Tio-benzimidazol con Sulfato de Dimetilo 

  Constenla Umaña, Manuel Arturo; Arias, Douglas (1979)

  Se efectuó la reacción del 2,2´-tiobis-benzimidazol con el sulfato de dimetilo por pasos. Se comprobó la formación de: 1,1´-dimetil-2,2´-tiobis-benzimidazol (2) y del diperclorato del 1,1´,3,3´-tetrametil-2,2´-tiobisbenz ...

• Estudio Químico de la Solanacea Markea Megalandra D'Arcy, Aislamiento de escopoletina de sus flores 

  Hasbun, Carlos; Calvo Pineda, Marco Antonio; Constenla Umaña, Manuel Arturo (1981)

  La solanacea Markea megalandra (Dun) D´Arcy se extiende desde Chiapas (México) hasta Venezuela, creciendo en las tierras altas (1900 metros sobre el nivel del mar). El material estudiado se recolectó en las faldas del ...

• Nota sobre la Preparación de un Dicatión Cuaternario de Azufre Divalente 

  Arias, Douglas; Constenla Umaña, Manuel Arturo (1979)

  A synthesis has been developed for the previously unreported salts of S,S-di-(1-methylbenzimidazol-2-yl)-S,S-dimethylsulfonium dication [3] derived from the sulfide [2] and dimethyl-sulfate.

• Cinética y Mecanismo de la Transposición Fotoquímica de Benzoiloxifosforinas 

  Constenla Umaña, Manuel Arturo (1980)

  Al irradiar los compuestos organofosforados del tipo benzoiloxifosforinas con luz visible de 380 nm hasta 760 nm en ciclohexano y en ausencia de oxígeno, se obtienen con buenos rendimientos los fosfaciclohexadienos (2) ...

• Pollinia as "pseudopalpi" on Archisepsis in Costa Rica: accidental or opportunistic? 

  Marshall, Stephen A.; Pupulin, Franco (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 

  Gracia Bondía, José M.; Várilly Boyle, Joseph C. (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 

  Dütsch, Michael; Gracia Bondía, José M.; Scheck, Florian; Várilly Boyle, Joseph C. (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 

  Constenla Umaña, Manuel Arturo; Chaverri Rodríguez, Adrián (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) 

  Carazo Rojas, Elizabeth; Fuentes González, Gilbert; Constenla Umaña, Manuel Arturo (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 

  Constenla Umaña, Manuel Arturo; Dimroth, Karl (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 

  Constenla Umaña, Manuel Arturo (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 

  Chaves Ramírez, Silvia Elena (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 

  Zúñiga Orozco, Andrés (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 

  Castillo Salazar, Christian Angelo (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 

  Jiménez Vargas, José Esteban; Oyuela Andino, Olvin; Bonilla, Josué H.; Blanco Coto, Mario Alberto (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 

  Godínez Sandí, Alejandro; Fallas Padilla, Diego Alonso; España Tapia, Sebastián; Zúñiga Villegas, Andrea; Castro Mora, Milena; Herrera Sancho, Óscar Andrey (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 

  Rivera Fernández, Erick; Amador Astúa, Jorge Alberto; Sáenz Soto, Ferrán (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 ...

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