Listar Ciencias básicas por título
Mostrando ítems 1038-1057 de 3130
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Effects of management and landscape composition on the diversity and structure of tree species assemblages in coffee agroforests
(2014-09-07)Understanding the processes that influence tree species composition in agricultural landscapes is essential for conservation of tropical biodiversity outside of protected areas. We analyzed the effects of landscape composition ... -
Effects of roost specialization on extinction risk in bats
(2015)Understanding causes and consequences of ecological specialization is of major concern in conservation. Specialist species are particularly vulnerable to human activities. If their food or habitats are depleted or lost, ... -
Effects of Seasonal Upwelling on Inorganic and Organic Matter Dynamics in the Water Column of Eastern Pacific Coral Reefs
(2015-11)The Gulf of Papagayo at the northern Pacific coast of Costa Rica experiences pronounced seasonal changes in water parameters caused by wind-driven coastal upwelling. While remote sensing and open water sampling already ... -
Effects of selective logging on the abundance, regeneration and short-term survival of Caryocar costaricense (Caryocaceae) and Peltogyne purpurea (Caesalpinaceae), two endemic timber species of southern Central America
(2007)In this study, we determined the effects of selective logging on the abundance of the last remnant populations of two tropical timber species with a restricted distribution, Caryocar costaricense and Peltogyne purpurea. ... -
Effects of simulated overfishing on the succession of benthic algae and invertebrates in an upwelling-influenced coral reef of Pacific Costa Rica
(2015)Overfishing and nutrient enrichment are among the major local stressors to coral reefs worldwide, as they can alter the benthic reef community by promoting fast growing algae and bioeroders. The Northern coast of Pacific ... -
Effects of temperature on the embryonic development and hatchling size of Betaeus emarginatus (Decapoda: Caridea: Alpheidae)
(2003)Betaeus emarginatus is an alpheid shrimp inhabiting rock pool environments characterized by strong fluctuations of ambient factors. Here we describe the embryonic development of B. emarginatus, and analyse the effects of ... -
Efficient syntheses of streptocarpone and (±)-a-dunnione
(2007)An efficient divergent synthesis of both streptocarpone and racemic α-dunnione from lawsone are described. A one-pot, formal [3+2] cyclization to form a furanonaphthoquinone directly provided a common intermediate. -
Egg clutch survival under prolonged paternal care in a Glass Frog, Hyalinobatrachyum talamancae
(2020-04-11)Previous studies have reported egg attendance as the most common protective behavior among the Neotropical frog family Centrolenidae. However, research on the effect of parental care and other factors thought to affect ... -
Egg sac construction by folding dead leaves in Pozonia nigroventris and Micrathena sp. (Araneae: Araneidae)
(2010)Published descriptions of egg sac construction behavior in araneids are scarce. We describe egg sac construction and oviposition in one individual of the poorly known araneid Pozonia nigroventris (Bryant 1936) and two ... -
Un ejemplo de intercambio científico entre Europa y América Latina: las investigaciónes de la expedición científica Austriaca en Costa Rica (1930)
(2008)En 1930, un grupo de científicos austriacos visitó Costa Rica y realizó una serie de investigaciones en distintas ramas de las ciencias naturales en diferentes puntos de este país centroamericano. El análisis de la ... -
El inflatón complejo
(1999) -
Elaboración de un lubricante potencialmente biodegradable de uso industrial a partir de quitosano, aceite de ricino y aditivos antioxidantes de origen natural
(2023-09-07)En la actualidad, la tecnología de los lubricantes se enfoca hacia la protección del medio ambiente. Sin embargo, la mayoría de los actuales lubricantes de uso industrial están conformados por aceites minerales como matriz ... -
Elasmobranch bycatch associated with the shrimp trawl fishery off the Pacific coast of Costa Rica, Central America
(2015)Demersal sharks and rays are common yet vulnerable components of the bycatch in tropical bottom-trawl fisheries. Little is known about the elasmobranch assemblages associated with most of these fisheries, particularly ... -
Electric-field control of single-molecule tautomerization
(2020)The electric field is an important parameter to vary in a single-molecule experiment, because it can directly affect the charge distribution around the molecule. Yet, performing such an experiment with a well-defined ... -
Electroactive copper (II) bimetallic self-assembled multilayers on Si (100)
(2012)Silicon (100) surfaces were modified by reacting 4-aminopyridine and Si–Cl bond. These surfaces were further used for tethering copper bimetallic complexes and growing monolayers and multilayers by changing the axial ... -
Electrochemical biosensor for quantitative determination of fentanyl based on immobilized cytochrome c on multi-walled carbon nanotubes modified screen-printed carbon electrodes
(2022)Fentanyl is a powerful synthetic opioid used to treat severe pain. New administration routes toward its illegal consumption for recreational purposes pose a growing threat to public health, either due to misuse or abuse ... -
Electrochemical determination of novel psychoactive substances by differential pulse voltammetry using a microcell for boron-doped diamond electrode and screen-printed electrodes based on carbon and platinum
(2021)25B-NBOMe, benzylpiperazine (BZP), 1-(3-chlorophenyl)piperazine (mCPP), and N,N-dimethyltryptamine (DMT) are potent hallucinogenic and stimulant drugs which have emerged as novel psychoactive substances (NPS). The ... -
Electronic structure of silicon-based nanostructures
(2007-08-30)We have developed a unifying tight-binding Hamiltonian that can account for the electronic properties of recently proposed Si-based nanostructures, namely, Si graphene-like sheets and Si nanotubes. We considered the sp3s∗ ...