Browsing Facultad de Ciencias Exactas y Naturales by Title
Now showing items 2606-2625 of 2712
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Two New Species of Edible Berries, One in Gaultheria L. and Other in Vaccinium L. (Ericaceae) from Costa Rica and Panama
(Universidad Nacional (Costa Rica), 2021-11-30)Estudios recientes sobre la flora de los páramos en Costa Rica, revelan dos nuevas especies endémicas taxones descritos aquí como Gaultheria paramicola A. Rojas y Vaccinium reptans A. Rojas, ambos conocidos sólo de Costa ... -
Two ways to be a velvet worm
(Universidad de Costa Rica (Costa Rica), 2019)There are two ways to be a velvet worm. One is to mate vaginally at a young age, give birth in any month and have small, scarce males. The other is to periodically inseminate through the body wall, with sexual equality in ... -
Ultraestructura de la glándula androgénica, espermatogénesisy oogénesis de camarones marinos (Decapoda: Penaeidae)
(Universidad de Costa Rica (Costa Rica), 1994-08-01)Se describe la glándula androgénica de Penaeus vannamei y P. Stylirostris (camarones thelycum abiertos). La glándula es una hebra celular que aparece asociada a los conductos deferentes desde la región proximal de la ampolla ... -
Ultrastructural demonstration of the model of Litopenaeus vannamei (Crustacea, Penaeidae) male sexual maturation and spermatozoal capacitation
(Invertebrate Reproduction and Development Vol.61 No.1, 2016-10-13)The present study demonstrates ultrastructurally the model of Litopenaeus vannamei male sexual maturation and spermatozoal capacitation. The results show that phase 1 of the model occurred in the seminiferous tubules and ... -
Understanding failures through the lifetime of a top-level supercomputer
(Academic Press Inc., 2021-04-20)High performance computing systems are required to solve grand challenges in many scientific disciplines. These systems assemble many components to be powerful enough for solving extremely complex problems. An inherent ... -
Understanding Space Weather: Solar Cycles and Magnetic Rossby Waves
(Universidad Nacional de Costa Rica, 2019-07-31)El objetivo de esta investigación es explorar si existe una relación entre las ondas magnéticas de Rossby rápidas o lentas y ciertas observaciones de la actividad solar de largo y muy largo plazo (meses, ... -
Understory bat roosts, availability and occupation patterns in a Neotropical rainforest of Costa Rica
(Revista de Biología Tropical, 2016-07-03)The strong link between bats and their roosts is widely recognized as being particularly significant. Despite this, roosting ecology of bats is poorly understood and much of the basic information is still unknown. In this ... -
Unexplored Character Diversity in Onychophora (Velvet Worms): A Comparative Study of Three Peripatid Species
(Sars International Centre for Marine Molecular Biology, Norway, 2012-12-17)Low character variation among onychophoran species has been an obstacle for taxonomic and phylogenetic studies in the past, however we have identified a number of new and informative characters using morphological, molecular, ... -
Uniciencia journal adopts the continuous publication model
(Universidad Nacional (Costa Rica), 2021) -
Unión interuniversitaria para el fortalecimiento de las Olimpiadas Costarricenses de Ciencias Biológicas como proceso de formación de los futuros profesionales en el área de las ciencias y la actualización de los conocimientos de los y las docentes de secundaria sobre biología
(Universidad Estatal a Distancia (UNED) (Costa Rica), 2015-04-28)Las Olimpiadas Costarricenses de Ciencias Biológicas promueven el estudio activo, participativo y significativo de las ciencias biológicas a nivel de la enseñanza media y preuniversitaria y potencian el nivel cognitivo ... -
La unión y formación de poros de las actinoporinas están determinadas por las propiedades fisicoquímicas de la membrana
(Academia de Ciencias de Cuba (Cuba), 2022)Introducción. Las actinoporinas (AP) son proteínas formadoras de poro (PFP) que se asocian a membranas conduciendo a la muerte celular. Sticholysinas I y II (St, StI/II) se encuentran entre las AP más potentes descritas ... -
Unveiling the hidden bat diversity of a neotropical montane forest
(PLOS ONE Vol.11 No.10, 2016-10-05)Mountain environments, characterized by high levels of endemism, are at risk of experiencing significant biodiversity loss due to current trends in global warming. While many acknowledge their importance and vulnerability, ... -
Usage and limitations of free and open-source software in Costa Rican local governments
(IEEE Explore, 2013-10-07)This paper presents results about the use and barriers that face free and open source software in the local governments in Costa Rica. Through an electronic survey, information was gathered from such governments, allowing ... -
Usando la red de estaciones SIRGAS de Costa Rica para la cuantificación de las discrepancias respecto de un procesamiento PPP en línea
(Universidad Nacional (Costa Rica), 2017-02)Se cuantificaron las discrepancias en las coordenadas geocéntricas [X,Y,Z] obtenidas entre soluciones GPS procesadas en línea con el software del Canadian Space Reference System (CSRS) bajo la modalidad de Posicionamiento ... -
Use and perception of open source by students of the national university in non IT careers
(Institute of Electrical and Electronics Engineers Inc., 2019-08-20)This paper discloses some initiatives that have been carried out by the National University with open source and an exploratory study of the use and perception of a part of the students of the National University that are ... -
Use and Perception of Open Source by Students of the National University in non IT Careers
(Instituto of Electrical and Electronica Engineers (IEEE), 2019)This paper discloses some initiatives that have been carried out by the National University with open source and an exploratory study of the use and perception of a part of the students of the National University that are ... -
Use of food and spatial resources by two frogs of the genus Dendropsophus (anura: Hylidae) from La Selva, Costa Rica
(Universidade de Sao Paulo, 2012-06)Differences in the use of resources by similar species have been related to a reduction in the interspecific competition that allows coexistence. Also, other factors, such as high availability of resources in the environment, ... -
Using Flashcards as a Didactic Resource for Teaching Statistics: The Experience in a Particular Didactics Course
(Universidad Estatal a Distancia, 2024-01-01)The aim of the systematization was to create a collection of cards by a group of students. These cards would serve as a didactic resource in teaching statistical or probabilistic concepts in the Costa Rican secondary education ... -
Using Flashcards as a Didactic Resource for Teaching Statistics: The Experience in a Particular Didactics Course
(Universidad Estatal a Distancia, 2024)The aim of the systematization was to create a collection of cards by a group of students. These cards would serve as a didactic resource in teaching statistical or probabilistic concepts in the Costa Rican secondary education ... -
Using Sniffer4D and SnifferV portable gas detectors for UAS monitoring of degassing at the Turrialba Volcano Costa Rica
(Advanced UAV, 2023)Since the completion of the first Sniffer UAS payload research article titled; Using UAS with Sniffer4D Payload to Document Volcanic Gas Emissions for Volcanic Surveillance: In this study the UAS system deployed carried ...