Browsing Facultad de Ciencias Exactas y Naturales by Title
Now showing items 1851-1870 of 2700
-
Muestreo de las Floraciones Algales Nocivas (FANs) en el Golfo de Nicoya, Puntarenas, Costa Rica
(2013-08-22)Las floraciones algales, conocidas como mareas rojas son cambios en la coloración del agua producidas por la proliferación de microorganismos pigmentados (Reguera 2002). Estos organismos presentan ciclos de crecimiento y ... -
Muestreo serológico de mamíferos menores capturados en un foco enzootico al virus estomatitis vesicular
(Universidad Nacional (Costa Rica), 1992)Se capturaron roedores menores en Grecia de Alajuela, un área enzoótica al virus Estomatitis Vesicular (VEV), con el objeto de analizar su posible papel en el ciclo de transmisión del virus. Durante un periodo de un año ... -
Mujeres en Ciberseguridad: Perspectiva desde el ámbito laboral costarricense
(Universidad Tecnológica de Panamá, 2019)Este trabajo analiza la participación de las mujeres como parte de la fuerza laboral en el área de ciberseguridad y la diferencia de género existente en dicho campo. Mediante entrevistas a profesionales y ... -
Multiparticle emission in the decay of Ar 31
(American Physical Society, 2014-06-25)A multihit capacity setup was used to study the decay of the dripline nucleus 31Ar, produced at the ISOLDE facility at CERN. A spectroscopic analysis of the β-delayed three-proton decay of 31Ar is presented for the first ... -
Multiplicación masiva de genotipos seleccionados de Tectona grandis en medio semisólido y en Sistemas de Inmersión Temporal, como una herramienta para programas de mejoramiento genético
(2021)La teca (Tectona grandis Linn) es una especie forestal reconocida como madera preciosa, de alto valor económico. Se propaga exitosamente por propagación vegetativa y por semilla, no obstante, estos procesos son lentos, ... -
Nanochitin: Chemistry, Structure, Assembly, and Applications
(ACS Publications, 2022)Chitin, a fascinating biopolymer found in living organisms, fulfills current demands of availability, sustainability, biocompatibility, biodegradability, functionality, and renewability. A feature of chitin is its ability ... -
Nanoestructuras de Silicio en Biomedicina y Biotecnología
(Universidad Nacional (Colombia), 2020)Actualmente ha crecido el interés por la fabricación y caracterización de nanoestructuras de silicio, entre las que se incluye nanohilos, pilares, tubos, conos, partículas, etc; existiendo diversos métodos para generar ... -
Nanofibrilación de celulosa extraída a partir del rastrojo de la piña (Ananas comosus)
(Universidad Nacional (Costa Rica), 2021)El sector agroindustrial ha tenido un crecimiento considerable en Costa Rica durante los últimos años alcanzando los primeros lugares en los productos de mayor exportación, ejemplos de esto son la piña y el banano, estas ... -
Nanopartículas de quitosano como sistema de liberación controlada principios activos
(Universidad Nacional (Costa Rica), 2011-02)Los fármacos constituyen una herramienta básica de la medicina para el tratamiento de enfermedades y afecciones en los organismos. Sin embargo, la dosificación muchos medicamentos de uso común acarrear desventajas como ... -
Natalidad de Chelydra serpentina (Testudines: Chelydridae) en Costa Rica
(Universidad de Costa Rica, 1996)Three Chelydra serpentina nests were monitored from September through October 1993. Maximum natality was 92% (mean 33.73%) and seemed to be associated with high temperature potasium and a moderate concentration of calcium ... -
National Inventory of Mercury Release into Different Environmental Sectors Estimated by United Nations Environment Programme (UNEP) Toolkit in Costa Rica
(United Nations Environment Programme (UNEP) Toolkit, 2017)This paper summarizes the national inventory of mercury released into all environmental sectors (air, water, land, impurity in products, general wastes and sector specific treatment/disposal) for the year 2008 in the country ... -
Nations work together to size up Caribbean tsunami hazards
(AGU.ORG, 2018-10-04)El Caribe es conocido por sus playas tropicales y centros de surf, pero no está exento de terremotos y tsunamis. Durante los últimos 500 años, esta región puede haber estado expuesta a aproximadamente 100 tsunamis, de los ... -
Near Surface Carbon Dioxide and Methane in Urban Areas of Costa Rica
(Scientific Research Publishing (China), 2015)Little information is available for Central America regarding methane and carbon dioxide mixing ratios in urban areas. This work reports a representative spatial and seasonal study of near surface carbon dioxide and ... -
Neighborhood structure influences the convergence in light capture efficiency and carbon gain: An architectural approach for cloud forest shrubs
(Tree Physiology vol.36 no.6 712-724 2016, 2016-03-24)Although plant competition is recognized as a fundamental factor that limits survival and species coexistence, its relative importance on light capture efficiency and carbon gain is not well understood. Here, we propose a ... -
Neighbourhood structure and light availability influence the variations in plant design of shrubs in two cloud forests of different successional status
(Annals of Botany, 2016-07)Background and Aims Plant design refers to the construction of the plant body or its constituent parts in terms of form and function. Although neighbourhood structure is recognized as a factor that limits plant survival ... -
Nematode assemblages in four ecosystems of Parque Nacional del Agua, Costa Rica
(Elsevier (Países Bajos), 2022)The soil nematode fauna of five locations situated in Parque Nacional del Agua (PNA) in Costa Rica is characterized and analyzed. Four ecosystems were sampled in each location: primary (undisturbed) forest, secondary (naturally ... -
Neotropical flowering epiphyte diversity: local composition and geographic affinities
(Universidad Nacional, Costa Rica, 2013)Worldwide, the highest diversity of vascular epiphytic plants resides in the Neotropics. The general pattern of taxonomic composition of the neotropical epiphytic flora has been described, but information regarding the ... -
Nesting ecology of East Pacific green turtles at Playa Cabuyal, Gulf of Papagayo, Costa Rica
(2014-07)East Pacific green turtles (Chelonia mydas), often referred to as black turtles, are smaller and exhibit a lower reproductive output than other populations of green turtles in the Atlantic, Indian and Western Pacific Oceans. ... -
Neutralización del efceto hemorrágico inducido por veneno Bothrops asper (Serpentes: Viperidae) por extractos de las plantas tropicales
(Universidad Nacional (Costa Rica), 1999)Organic extracts representing 48 species included in 30 families of Costa Rican tropical plants were evaluated for their hability to neutralize hemorrhagic acfivity lnduced by the venom of the snake Bothrops aspero Abioassay ... -
New advances in the method validation, extraction methods and measurement uncertainty for the determination of water-soluble hexavalent chromium in hydraulic cemen
(Elsevier, 2021)The quantification of Cr (VI) in the cement matrix is highly important, given the possibility of suffering illnesses including dermatitis, induced nasal carcinoma, and DNA damage produced by inhalation of and/or direct ...