Listar Ciencias básicas por título
Mostrando ítems 21-40 de 3121
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A Constrained 3D Density Model of the Upper Crust from Gravity Data Interpretation for Central Costa Rica
(2010-01-05)The map of complete Bouguer anomaly of Costa Rica shows an elongated NW-SE trending gravity low in the central region. This gravity low coincides with the geographical region known as the Cordillera Volcánica Central. It ... -
A correction to the Lepanthes guatemalensis group (Orchidaceae: Pleurothallidinae) in Costa Rica, with a new species
(2021)The true Lepanthes edwardsii is first recorded for the flora of Costa Rica, described and illustrated on the basis of a Costa Rican voucher. The taxon previously recorded under that name is described as new to science as ... -
A distinctive oral phenotype points to FAM20A mutations not identified by Sanger sequencing
(2015-10-04)Biallelic FAM20A mutations cause two conditions where Amelogenesis Imperfecta (AI) is the presenting feature: Amelogenesis Imperfecta and Gingival Fibromatosis Syndrome; and Enamel Renal Syndrome. A distinctive oral phenotype ... -
A facile method for the preparation of bishomopropargylic alcohols from acyl chlorides
(2014)Controlled dilithiation of propargyl bromide with two equivalents of n-butyllithium, in the presence of TMEDA, produces the operational equivalent of the dianion 1,3-dilithiopropyne. The latter reacts efficiently with ... -
A Facile Method for the Titration of Organolithium Reagents using Naphtylamine or Naphtylmethylamine as Indicators
(2019)A simple method for the titration of alkyllithiums with sec-butanol, using naphtylamine or naphtylmethylamine as color indicator, is reported. Both amines gave sharp-end points, easily determined by color changes from ... -
A genome‐wide quantitative trait locus (QTL) linkage scan of NEO personality factors in Latino families segregating bipolar disorder
(2017)Personality traits have been suggested as potential endophenotypes for Bipolar Disorder (BP), as they can be quantitatively measured and show correlations with BP. The present study utilized data from 2,745 individuals ... -
A Geometric Splitting Theorem
(2019)Let G = G1...Gl be a connected noncompact semisimple Lie group with Lie algebra g = g_1+g_2+....+ g_l acting topologically transitive on a manifold M. We obtain a geometric splitting of the metric on M that consider ... -
A High-Throughput Screen Identifies a New Natural Product with Broad-Spectrum Antibacterial Activity
(2012)Due to the inexorable invasion of our hospitals and communities by drug-resistant bacteria, there is a pressing need for novel antibacterial agents. Here we report the development of a sensitive and robust but low-tech and ... -
A highly threatened new species of Vanilla from Costa Rica
(2018)A new species of Vanilla is described and illustrated from the southeastern tip of Costa Rica, close to the border with Panama. Vanilla karenchristianae was found in a region of the country that has no protected areas and ... -
A just overtime discovery: another new species of Echinosepala (Orchidaceae) from Costa Rica
(2022-08-13)Echinosepala truncata is described as new to science and illustrated from the holotype. It is compared with E. tomentosa, from which it differs by the sparsely lanate ovary, the narrowly obovate, apically rounded synsepal, ... -
A mathematical model with nonlinear relapse: conditions for a forward-backward bifurcation
(2023)We constructed a Susceptible-Addicted-Reformed model and explored the dynamics of nonlinear relapse in the Reformed population. The transition from susceptible considered at-risk is modeled using a strictly decreasing ... -
A melt-focusing zone in the lithospheric mantle preserved in the Santa Elena Ophiolite, Costa Rica
(2015-08-01)The Santa Elena Ophiolite in Costa Rica is composed of a well-preserved fragment of the lithospheric mantle that formed along a paleo-spreading center. Within its exposed architecture, this ophiolite records a deep section ... -
A Mesoamerican origin of cherimoya (Annona cherimola Mill.): Implications for the conservation of plant genetic resources
(2017)Knowledge on the structure and distribution of genetic diversity is a key aspect to plan and execute an efficient conservation and utilization of the genetic resources of any crop as well as for determining historical ... -
A Metabolic Widget Adjusts the Phosphoenolpyruvate-Dependent Fructose Influx in Pseudomonas putida
(2016)Fructose uptake in the soil bacterium Pseudomonas putida occurs through a canonical phosphoenolpyruvate (PEP)-dependent sugar transport system (PTSFru). The logic of the genetic circuit that rules its functioning is puzzling: ... -
A methane sink in the Central American high elevation páramo: Topographic, soil moisture and vegetation effects
(2020)Methane (CH4) is a strong greenhouse gas with a global warming potential 23 times larger than that of carbon dioxide. Characterizing ecosystems as either sources or sinks for methane and their magnitudes informs on biosphere ... -
A method for prediction of California summer air surface temperature
(2004-12-21)While significant progress has been made in seasonal climate prediction in recent years, summertime mid-latitude climate prediction remains problematic [e.g., Gershunov and Cayan, 2003]. Several previous studies have ... -
A microbial consortium from a biomixture swiftly degrades high concentrations of carbofuran in fluidized-bed reactors
(2016)An on-farm biopurification system (BPS) biomixture, with proven capacity to degrade carbofuran (CBF) was used as inoculum for a selective-enrichment process to obtain a bacterial consortium capable of using CBF as a sole ... -
A mixed-primal finite element approximation of a sedimentation–consolidation system
(2016)This paper is devoted to the mathematical and numerical analysis of a strongly cou- pled flow and transport system typically encountered in continuum-based models of sedimentation–consolidation processes. The model focuses ... -
A mixed-primal finite element method for the coupling of Brinkman-Darcy flow and nonlinear transport.
(2021-01)This paper is devoted to the mathematical and numerical analysis of a model describing the interfacial flow-transport interaction in a porous-fluidic domain. The medium consists of a highly permeable material, where the ... -
A molecular study of Neophyllaphis varicolor (Hemiptera, Aphididae) in Costa Rica
(2019-07)The genus Neophyllaphis (Takahashi) (Aphididae: Neophyllaphidinae) is composed of 18 species; however, in the Americas only nine species have been reported previously. A new species, Neophyllaphis varicolor Miller & ...