Browsing Facultad de Ciencias Exactas y Naturales by Title
Now showing items 1441-1460 of 2567
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Historical Tsunamis at the Costa Rican Caribbean Coast
(Universidad de Costa Rica, 2021-04-22)Aún cuando los tsunamis son poco frecuentes en el Caribe de Costa Rica, pueden llegar a ser destructivos. En Costa Rica existe la creencia errónea de que no hemos tenido tsunamis. Sin embargo, los autores encontraron ... -
Los híbridos de Pleopeltis (Polypodiaceae, Polypodiophyta) en México: novedades y precisiones
(Universidad Nacional (Costa Rica), 2017)Antecedentes y Objetivos: En México, hasta el momento, se conocen cuatro híbridos de Pleopeltis. Estos híbridos naturales forman parte de los procesos de especiación y contribuyen a aumentar la diversidad taxonómica del ... -
Holistically Managing Pathogens and Nutrients in Urbanizing Tropical Towns: Can Sanitation Technologies Create Safer Conditions for Beach Recreation?
(ACS Publications, 2021-03-02)Rapidly urbanizing coastal communities are prone to overpopulation and unrestrained growth that result in pathogen and nutrient emissions, which impair beach water quality and jeopardize human and environmental health. ... -
Horizontal transport and seasonal distribution of nutrients, dissolved oxygen and chlorophyll-a in the Gulf of Nicoya, Costa Rica: a tropical estuary
(Elsevier, 2002)The distributions of salinity, temperature, nutrients, dissolved oxygen and chlorophyll-a (chl-a) concentrations in the Gulf of Nicoya, Costa Rica, during the rainy and dry seasons are presented. In the rainy season, the ... -
Hormone-induced spawning of wild and captive-grown spotted rose snapper Lutjanus guttatus using carp pituitary suspension and human chorionic gonadotropin
(Universidad Autónoma de Baja California, México, 2011)Hormone-induced spawning of the spotted rose snapper Lutjanus guttatus was studied using wild and cage-grown fish. Carp pituitary suspension (CPS) and human chorionic gonadotropin (hCG) were assessed. Wild females (0.7–2.1 ... -
Human resources in computer sciences in Costa Rica: The elusive gap between supply and demand
(International Conference on Information Society, 2017-07-17)We analyze in this paper the supply and demand of human resources in computer sciences in Costa Rica. This is done with the aim of validating claims made by the local media about a large deficit of professionals for ICT ... -
Hydroclimatic and ecohydrological resistance/resilience conditions across tropical biomes of Costa Rica
(John Wiley & Sons (Estados Unidos), 2017)Water resources management in the tropics is challenged by climate variability and unregulated land use change and their impacts on the complex interactions between vegetation, soil, and atmosphere. This study focuses ... -
Hydrogeochemical baseline in a human altered landscape of the Central Pacific coast of Costa Rica
(Springer Nature, 2020)Abstract Groundwater pollution in tropical and human-altered coastal landscapes is receiving novel attention due to decreasing in annual recharge as a consequence of recurrent droughts and overexploitation, whereby saline ... -
Hydrogeological responses in tropical mountainous springs
(Taylor and Francis Ltd., 2018)This study presents a hydrogeochemical analysis of spring responses (2013–2017) in the tropical mountainous region of the Central Valley of Costa Rica. The isotopic distribution of δ18O and δ2 H in rainfall resulted ... -
Hydrological dataset of a sub-humid continental plain basin (Buenos Aires, Argentina)
(Elsevier, 2020)The Chaco-Pampean Plain (Argentina) is the strongest eco- nomic region and the most inhabited in the country, comprising approximately 66% of the country’s population (26,500 million) [1] . In this region, surface slopes ... -
Hydrometeorological Factors Controlling the Stable Isotopic Composition of Precipitation in the Highlands of South Ecuador
(American Meteorological Society (Estados Unidos), 2022-07)Knowledge about precipitation generation remains limited in the tropical Andes due to the lack of water stable isotope (WSI) data. Therefore, we investigated the key factors controlling the isotopic composition of precipitation ... -
Hydrostatic limit for the symmetric exclusion process with lonh jumps: supper-diffusive case
(Universidad de Costa Rica, 2020-12-17)Hydrostatic behavior for the one dimensional exclusion process withlong jumps in contact with infinite reservoirs at different densities are de-rived. The jump rate is described by a transition probabilitypwhich isproportional ... -
ICT Adoption and Use in Costa Rican Export Companies
(Infonomics Society, 2015)We study the ICT adoption and use in Costa Rican export companies based on the results of a field survey. The e-commerce readiness/intensity/ impact model, developed by the Organisation for Economic Cooperation and Development ... -
ICT professional's training programs certification. Synonymous of professional quality, continuous improvement and development
(38th Latin America Conference on Informatics, CLEI 2012 - Conference Proceedings, 2013)This article presents a summary of the experience in the accreditation process of the informatics engineering careers, from the concepts definition, documents and from the topic evaluation instruments. The article pretends ... -
Ictiofauna asociada al manglar de Isla Palo Seco, Puntarenas, Costa Rica
(Universidad Nacional (Costa Rica), 2015)Los manglares son un tipo de vegetación dominante en los estuarios tropicales y subtropicales (Blaber,2007. Estos ecosistemas se caracterizan por su gran variación estructural y por sus exclusivas condiciones fisicoquímicas ... -
Identificación de cuatro especies de Clupeiformes (Actinopterygii) mediante análisis de secuencias de ADN mitocondrial en áreas de explotación pesquera del Golfo de Nicoya, Costa Rica
(Universidad Nacional, Costa Rica, 2021-01)Las sardinas junto con las anchovetas constituyen unos de los grupos de mayor importancia en la pesquería del golfo de Nicoya. Son alimento para peces de mayor tamaño y aves marinas, por tanto, no solo sufren explotación ... -
Identificación de especies de Meloidogyne asociadas a plantas ornamentales de altura en Costa Rica
(Universidad de Costa Rica, 2015)Identificación de especies de Meloidogyne asociadas a plantas ornamentales de altura en Costa Rica. El objetivo del presente trabajo fue identificar especies de nematodos del género Meloidogyne asociadas a plantas ornamentales ... -
Identificación de explosivos Orgánicos en Indicios Post-Explosión mediante GC-MS y GC-NPD
(Tecnológico de Costa Rica, 2020-07)Se implementó y validó un método para la identificación de explosivos por medio de cromatografía de gases acoplada a un detector de espectrometría de masa (GC-MS) y por cromatografía de gases de doble columna acoplada a ... -
Identificación de lignanas en hojas de Rollinia mucosa (JACQ) bail. Annonaceae
(Universidad Nacional (Costa Rica), 2001)El extracto etanólico obtenido por maceración de las hojas de Rollinia mucosa fue extraído sucesivamente con los siguientes disolventes de polaridad creciente: hexano, cloroformo y acetato de etilo. Diluciones alcohólicas ... -
Identificación de metabolitos secundarios con actividad antimicrobiana y capacidad antioxidante presentes en mieles de abejas sin aguijón procedentes de Costa Rica
(Universidad Nacional (Costa Rica), 2012-11)Valora mediante cromatografía en capa fina (CCF) la presencia de metabolitos secundarios con capacidad antioxidante y actividad antimicrobiana en 63 extractos en fase orgánica de mieles de abejas sin aguijón procedentes ...