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24RNA-SEQ analysis in hiPSC-derived neurons from patients with schizophrenia
(2019-07-26) Stertz, Laura; Pei, Guangsheng; Jia, Peilin; Li, Shenglan; Raventós Vorst, Henriette; Liu, Ying; Zhao, Zhongming; Walss Bass, Consuelo
Background: Human induced pluripotent stem cells (hiPSC) have provided a new way of studying schizophrenia (SZ), by allowing the establishment of brain cellular models accounting for the patient genetic background. Here we conducted an exploratory RNA-sequencing profiling study of cell lines derived from hiPSCs generated from lymphoblastoid cell lines (LCL) of subjects from the population isolate of the Central Valley of Costa Rica (CVCR). Methods: Five cell lines (LCL, hiPSC, NPC, cortical neurons and astrocytes) derived from 6 healthy controls and 7 SZ patients from the CVCR were generated using standard methodology. RNA from these cells was sequenced using Illumina HiSeqTM2500. Normalization and differential expression (DE) analysis were performed using DESeq2 (|FC| > 1.5 e BH corrected p-value < 0.05). Functional enrichment analysis was performed using DAVID 6.8. Results: hiPSC-derived neurons were responsible for 94.4% of the variance seen on DE analyses. We found 454 genes differently expressed on neurons differentiated from SZ compared to HC. Noteworthy, one of these genes was ZNF804A (FDR = 0.032), a strong candidate gene for schizophrenia susceptibility, with solid evidence of association from GWAS. Discussion: ZNF804A is a zinc finger protein has been shown to regulate neurite outgrowth, dendritic spine maintenance and activity-dependent structural plasticity. It is expressed broadly throughout the brain, especially in the developing hippocampus and the cortex, as well as in the adult cerebellum. A great advantage of using iPS-derived cells is that the effect of outside environmental influences, such as use of medications, is removed and only the effects of genetic composition, which is unchanged by transformation, are left. The DE of ZNF804A only on hiPSC-neurons highlight the crucial role that this protein can have on SZ pathology during neuronal development. Functional studies will help us further characterize this mechanism.
507. Association of NRXN3 deletion with schizophrenia and bipolar disorder
(2017-05-17) Shavit, Ayal; Gonzalez, Jessica; Chavez, Maricela; Rodriguez, Marco; Camarillo, Cynthia; Ramirez, Mercedez; Zavala, Juan; Contreras Rojas, Javier; Raventós Vorst, Henriette; Flores, Deborah; Jerez, Alvaro; Ontiveros, Alfonso; Nicolini, Humberto; Escamilla, Michael; Gonzalez, Suzanne
Schizophrenia (SZ) and bipolar disorder (BD) are the most severe neuropsychiatric disorders affecting 1.2% and 4.4% of Americans, respectively. Certain genes coding for proteins involved in pre-synaptic machinery are thought to play a role in the pathophysiology of the disorder. Deficits in the calcium channel regulator gene NRXN3 have been associated with behaviors of impulsivity and alcohol and drug dependence, which are traits characteristic of BD and SZ.
846. Human-derived astrocytes from schizophrenia patients express lower levels of GFAP and S100B
(2017-04-29) Stertz, Laura; Raventós Vorst, Henriette; Walss Bass, Consuelo
Schizophrenia (SZ) is a debilitating psychiatric disorder with a worldwide prevalence of 1%; there is a strong genetic component, with an estimated heritability of 70-85%. Glial cells mediate crucial functions in the CNS and alterations in the function of these cells may be an underlying mechanism for SZ development. Here we use astrocytes derived from induced pluripotent stem cells (iPSCs) from subjects from the population isolate of the Central Valley of Costa Rica (CVCR) to explore a role for astrocytes in SZ pathogenesis.
Actas del V Congreso ISUF-H Costa Rica 2021: Ciudades espontáneas versus ciudades planificadas: distintos retos, distintas realidades
(2021-12) Acosta Schnell, Sabrine; García González, María Cristina; Guerrero López, Salvador; Cedeño Zambrano, Héctor Gonzalo; Cedeño Delgado, Tatiana Gabriela; Córdoba Hernández, Rafael; Martí Guitera, Lucas; Ribeiro Botechia, Flavia; Fornaciari Ferreira, Amanda; Vieira Leal, Lina; Ramos Vieira, Gabrielly Salatiel; Margotto Barroca, Vitoria; Galdeano Pérez, Iñigo; Pizarro Rosado, Marina Isabel; López Narváez, María Fernanda; Zárate García, Claudia Verónica; Montiel Cerna, Sofía Franchesca; Naranjo Serrano, Gabriela; Masís Morales, Adriana; Mínguez Martínez, Enrique; López Garre, Andrea; Mínguez Ros, Enrique; Solans Ibáñez, Indibil; Zaguirre Fernández, Juan Manuel; van Lidth de Jeude, Marije; Schütte, Oliver; Schroeder, Stella; Sagüés Silva, Alicia Fernanda; Chacón Gutiérrez, Diego Pablo; Mara Nespolo, Juliana; de Lourdes Bernartt, Maria; Longhi de Oliveira, Suelyn Maria; Bordin, Rodrigo; González López, Jorge Leonardo; Pedraza Gómez, Luis Francisco; Salazar Martínez, Bertha Lilia; Vázquez Honorato, Luis Arturo; Caldas Torres, Patricia; Chavarría Núñez, Dania María; Brettas Baptista, Izabela; de Toledo Magalhães, Carlos Henrique; Sosa Espinosa, Asenet; Casar Furió, María Emilia; Monclús Fraga, Francisco Javier; Díez Medina, Carmen; González García, Isabel; Santiago Rodríguez, Eduardo de; Hernández Partal, Sonia; Lacilla Larrodé, Elena; Bergasa Pascual, José Ramón; Flores Trávez, Carla; Naranjo Serrano, Gabriela; Solís Trapero, Eloy; Ruiz Apilánez, Borja; Calvo Sánchez, Violeta; Chacón Coronado, Edward; Sardá Ferran, Jordi; López Frasca, Stella; Peláez Sánchez, Ronald Mynor; Rivera Gonzalez, Oscar Daniel; Pinargote Pico, Luis Angel; Acosta, Jorge; Mazón, Johny; Espinoza Macías, Marcelo; Vallejo, Sebastián; Wong Lent, Cristina; Durán Segura, Luis Armando; Jiménez Corrales, Andrés; von Breymann Miranda, Helga
En el año 2021 celebramos en Costa Rica la V edición del Congreso ISUF-H, los días 1, 2 y 3 de diciembre, con la Escuela de Arquitectura de la Universidad de Costa Rica como anfitriona del evento. El congreso “Ciudades espontáneas versus ciudades planificadas: distintos retos, distintas realidades” propuso como eje central una reflexión crítica sobre los procesos de urbanización planificada y urbanización espontánea, en el cual se fomente un abordaje de las ciudades como expresión de organización social, económica, ambiental y cultural, enfatizando el carácter ideológico de la urbanización y subrayando su continua construcción como resultado de construcciones complejas. La celebración de un nuevo congreso en América Latina, permitió reforzar la tradición crítica en el abordaje de las ciudades, y reforzar también la necesidad de plantear una perspectiva latinoamericana de los estudios urbanos, y por consiguiente de una teoría urbana latinoamericana. En esta ocasión el congreso se centró en ahondar en la temática de la forma urbana, desde perspectivas transversales que involucren las amplias disciplinas que asumen como objeto de discusión las problemáticas de la ciudad contemporánea y cuestionan la dicotomía planteada entre lo espontáneo y lo planificado. Para la Escuela de Arquitectura de la Universidad de Costa Rica y su Laboratorio de Ciudad y Territorio es un honor haber podido llevar a cabo esta nueva edición del congreso de la Asociación ISUF-H como segunda sede en un país latinoamericano. Relevante para fortalecer la temática de la forma urbana en la región, reforzando alianzas y estableciendo nuevas redes que permitan compartir conocimientos a partir de las experiencias de esas diversidades urbanas. Auspiciar el debate en torno a la morfología urbana y las diferencias entre esas ciudades espontáneas y las planificadas, fue una oportunidad para reunir a expertos de las distintas latitudes hispánicas.
Algunos elementos en torno al desarrollo artesanal indígena y el marco institucional
(1984) Chang Vargas, Giselle
Analysis of single nucleotide polymorphisms in miRNA genes and their role in schizophrenia etiology
(2014-02-15) Bolaños Palmieri, Patricia; Raventós Vorst, Henriette
Schizophrenia is a severe neuropsychiatric disease that in spite of having a clear genetic component in its etiology, the genes involved have not yet been unequivocally identified and only explain a small percentage of the cases. Within the complex scenario of gene expression regulation, microRNAs have been implicated in the post-transcriptional regulation of mRNA. This mechanism of protein synthesis regulation has been linked to the correct formation of synapses, which translates in the ability to learn and other higher cognitive functions. Methods: miRNA candidate genes were established according to their genomic location and previous reports of differential expression in schizophrenic brains. Further in silico analysis was carried out in order to establish the targets for miRNA regulation and their relationship to the pathology. SNP genotyping analyses were performed in a sample of schizophrenic probands and their nuclear family members from Costa Rica, in order to establish an association to disease status. Results: A search of the available literature revealed a total of 60 miRNA differentially expressed in brains of schizophrenic patients, of which 12 were located in genomic regions of interest. Amongst the targets of posttranscriptional regulation are the Neurotrophin signaling pathways that have been implicated in important synaptic and neuronal processes. This result strengthens the hypothesis that these miRNA can be involved in disease etiology. Of the 4 SNPs genotyped only rs41283391 on miR-195 was polymorphic in our sample, however the association to Schizophrenia diagnosis was not significant (n = 317, Z = 0.797, p = 0.42). Conclusion: This research project adds further information to the hypothesis of the involvement of the miRNA regulation pathway in neuropsychiatric diseases. Even though the analysis of these particular SNPs gave no evidence of association, it is plausible that further sequence analysis could reveal more information about variants that could influence disease etiology. Another important outcome of this project is the establishment of further hypothesis for future research projects, some of which are already underway.
Cellular-level characterization of Dengue and Zika virus infection using multiagent simulation
(2018-09-13) Alvarado, Andreína; Corrales Barquero, Ricardo; Leal, María José; de la Ossa Osagueda, Álvaro; Mora Rodríguez, Rodrigo Mora; Arroyo Portilla, Manuel Francisco; Gómez Montero, Andrea; Calderón Castro, Alan; Arias Arias, Jorge Luis
In this paper we present a computational model aimed at characterizing the Zika viral infection at a cellular level based on measurements done on viral Dulbecco plaques over time, and describe our current state of progress in the modeling task. So far we have developed an agent-based simulation model of the dispersion of the virus on the cells conforming the viral plaque. The growth rate of the viral plaques and the number of cells counted on each plaque were used to characterize the viral infection in terms of parameters related to the fate of infected cells, such as the probability of a cell infecting its neighboring cells and the probability of an infected cell of dying at any given moment. The model can be used to predict viral plaque growth patterns similar to those observed in the laboratory. Our current efforts focus on optimizing the model parameters to fit the experimental data. Further development of the model includes the description of viral infection kinetics of specific viral strains. Our model has been developed using the agent-based modeling language Netlogo.
Climate scenarios and impacts of droughts and other hydrometeorological events in the Central American dry corridor
(2019) Alfaro Martínez, Eric J.; Pérez Briceño, Paula Marcela
Predicting rainfall during April-May-June (AMJ), as the first peak of the rainy season in the Central American isthmus, is very important since it has been observed that more or less humid conditions during AMJ tend to be preceded by early or late starts of the rainy season. A late onset of rainfall, for example, followed by drier than normal conditions during MJ and by a subsequent period of intense summer or heatwave, can significantly affect key socioeconomic sectors in the isthmus such as hydropower generation, drinking water supply or agriculture. In this presentation, data from 162 rainfall stations were used to construct predictive models for MJ as the first peak of the rainy season, using Canonical Correlation Analysis (CCA). The aspects to predict during MJ are rainfall accumulation and the Normalized Precipitation Index (NPI) in Central America. The sea surface temperature (SST) anomalies observed in the 63°N - 10°S and 152° E - 15°W domain were used as predictors. The CCA models, using the SST anomalies in February, show a good predictive ability of the accumulations and the NPI during MJ, in an important region of Central America. The results showed that warmer (cold) conditions in the eastern equatorial Pacific SST anomalies, along with colder (warmer) conditions in the North Tropical Atlantic during February, tend to be correlated with drier (wet) periods during the next MJ bimester in virtually the entire isthmus. This suggests that the SST could modulate rainfall during MJ in Central America by influencing the position of the Inter-Tropical Convergence Zone and the magnitude of trade winds.
El contexto en el aprendizaje de las ciencias, ¿de quién y para qué?
(2021-05-01) Lorca Marín, Antonio Alejandro; Retana Alvarado, Diego Armando
El siglo XXI ha traído aparejado una serie de cambios sociales, tecnológicos e incluso laborales que hacen que nos planteemos nuestro paradigma educativo y, por ende, sus perspectivas a nivel ontológico, epistemológico y metodológico. En esta comunicación, se expone la experiencia llevada a cabo bajo una metodología por indagación y en la que un taller cuestionando la Homeopatía, sirve como foco de reflexión para ejemplificar nuevas perspectivas en el aula. El realizar un acercamiento a los contenidos propios de las asignaturas de física y química a través de la experimentación, donde las afirmaciones en ciencias se hagan a través de los datos y no como dogmas de fe, se plantean como metodologías necesarias para una ciudadanía continuamente inmersa en un mar de opiniones. El cuestionar los medios de comunicación (foco de información para muchos) nos acerca al pensamiento crítico y escepticismo que tanto se reclama en nuestras aulas.
Contribuciones del Dr. Michael J. Snarskis a la Arqueología costarricense
(2015) Bozzoli Vargas, María Eugenia; Sánchez Pereira, Maureen; Corrales Ulloa, Francisco; Montero Villalobos, Mavis Lili; Conejo Barboza, Geraldine; Fernández Esquivel, Patricia; Drolet, Robert P.; Arrea Siermann, Floria; Ibarra Rojas, Eugenia; Salgado González, Silvia; Vicente Guerrero, Juan; Lange, Frederick W.; Araya Jiménez, María del Carmen; Salgado González, Silvia
Libro que compila las ponencias presentadas por personas arqueólogas durante el simposio "Contribuciones del Dr. Michael J. Snarkis a la arqueología costarricense", realizado el jueves 9 y viernes 10 de agosto del 2013, en honor del arqueólogo norteamericano, luego de su partida el 24 de enero del 2011. La actividad fue convocada por el Posgrado en Antropología y la Escuela de Antropología, ambas de la Universidad de Costa Rica y participaron arqueólogos y arqueólogas que trabajaron de cerca con Snarskis como colegas, asistentes de investigación o estudiantes. Luego del simposio diez de las ponencias fueron reelaboradas como artículos por sus respectivos autores o autoras. Así, María Eugenia Bozzoli reconstruye el contexto histórico en el cual se desenvolvió Snarskis; Maureen Sánchez precisa los aportes en el ámbito del análisis lítico; Francisco Corrales, Mavis Montero y Geraldine Conejo revisan las contribuciones que hizo al período formativo en Costa Rica (2000-300 a.c.); Patricia Fernández indica que Snarskis retomó la idea de la procedencia de los objetos de oro de Colombia planteado por otras personas arqueólogas, lo cual lo condujo a establecer rasgos cronológicos para las primeras piezas de oro; Roberto Drolet narra la experiencia de ambos en la investigación arqueológica desarrollada durante la construcción de la Represa Hidroeléctrica de Boruca en el Sur de Costa Rica, en 1980; Floria Arrea destaca la labor docente del arqueólogo; Eugenia Ibarra analiza el papel que jugó la etnohistoria en la labor de él; Silvia Salgado aborda los elementos que integran el modelo de evolución social planteado en la tesis doctoral del arqueólogo de 1978; Juan Vicente Guerrero se refiere al último trabajo de Miguel en el sitio Loma Corral en Bahía Culebra, Guanacaste, en el 2006 y Frederick Lange escribe acerca de las ideas de Snarskis sobre la presencia de la influencia Mesoamericana en Costa Rica. Por todo ello, el libro es una referencia necesaria en el conocimiento del trabajo del arqueólogo Michael J. Snarskis.
Costa Rica Aerospace Camp 2015: Experiences and Results
(2016-09) de Lemos Medina, Leonora; Mora Vargas, Andrés
The first Costa Rican Aerospace Camp 2015 was an outreach and education activity where participants had active contact with the entire process of constructing and operating sounding rockets. It included lectures on theoretical concepts, simulation, instrumentation, and hands-on construction of the rockets, culminating with their launch. In this paper, we present the lessons learned during the organization, development, and follow-up of over 50 participating students from several technical and socio-economic backgrounds. A first of its kind in Costa Rica, the camp was organized by the Department of Mechanical Engineering of the University of Costa Rica (UCR) and it was held from July 20th-22nd, 2015 in the campus of the UCR located in the province of Guanacaste. The main objective of the camp was to engage students in the classroom and inspire them to continue their undergraduate studies in the Science, Technology, Engineering and Mathematics (STEM) fields as well as propel them to integrate the growing cluster of aerospace companies in Costa Rica. There were over 90 participants including staff, invited lecturers, organizers, and students. The camp attracted a large amount of national media coverage since it was the first time senior high school and freshmen university students, both female and male, from all over the country came to work together to, at the end of the camp, launch their sounding rockets with an altimeter as payload. The rockets reach up to 400 meters and after recovery their data was analyzed by the students. In this paper, we will present the application process the students went through, the teaching methodologies applied during the camp, the data representing the background of the participating students, the outcome of the camp, a follow up on the students and the conclusions we have drawn from this initial experience and how we expect to improve it during the upcoming 2016 edition of the camp.
Differences in BADL, IADL and Cognitive Status in a Costa Rican Sample of older adults
(2011) Johnson, David K.; Salazar Villanea, Mónica; Garnier Villareal, Mauricio
Diseño y validación de una escala para el análisis de las emociones de maestros en formación inicial hacia la metodología de indagación
(2021-11-30) Retana Alvarado, Diego Armando; Vázquez Bernal, Bartolomé; De las Heras Pérez, María Ángeles; Jiménez Pérez, Roque
En este estudio se diseñó una escala para valorar el grado de intensidad de las emociones que maestros en formación inicial experimentan hacia la metodología indagatoria. La muestra estuvo formada por 57 estudiantes de la asignatura Didáctica de Ciencias de la Naturaleza I correspondiente al Grado de Maestro en Educación Primaria de la Universidad de Huelva (España). El instrumento mide la intensidad de siete emociones negativas y siete emociones positivas. Los datos se sometieron a análisis descriptivo y análisis factorial exploratorio. Los resultados obtenidos muestran que la escala es un instrumento válido para estimar el grado de intensidad de las emociones. Predomina la manifestación de emociones positivas como interés y aceptación. Las emociones negativas más intensas son temor, susto y tensión. El temor correlaciona positivamente con susto, enojo, tensión, frustración y rechazo. El interés correlaciona con aceptación.
Effects of Celmanax supplementation to prepartum dairy cows on colostrum quality and the subsequent growth and health of their calves
(2014) Campos Granados, Carlos Mario; Rojas Bourrillón, Augusto; Elrod, Charles C.
The objective of this study was to assess the effects of supplementing prepartum dairy cows with a product derived from yeast culture and enzymatically hydrolyzed yeast cell wall (Celmanax (CEL), Vi-COR, Mason City, IA) on colostrum quality and the subsequent health and performance of their calves. Thirty prepartum multiparous Jersey cows were blocked by parity, body condition 21 days before expected calving date and productive and reproductive performance, and randomly assigned within block to 1 of 2 treatments (n=15) from 21 days before expected calving date until calving. Rations were top-dressed with CEL at the rate of 0 or 40 g/d throughout the experiment. Calves were fed 3 L of colostrum from their dam within two hours of birth and then 4 L of whole milk daily through week 8. Total Ig in colostrum from each cow was evaluated at 25oC from the first milking with a Colostrometer™ and a sample was taken for determination of IgG by ELISA. Approximately 48 hours after birth, a blood sample was drawn by venipuncture from each calf for the determination of serum protein by refractometer and IgG by ELISA. Daily feed intake, weekly weight and hip height and the incidence of pneumonia and scours were recorded. Data were analyzed using mixed models with repeated measures over time. Total Ig in colostrum was significantly increased by CEL treatment (P<0.05; 90.06±23.74 vs. 105.94±17.59 mg/mL for 0 and 40 g/d, respectively) but there was no effect on colostrum yield or IgG content (P>0.05). There was no effect of treatment on birth weight, serum protein or serum IgG (P>0.05). Average daily gain (382.86±61.20 vs. 410.94±51.22 g/day for 0 and 40 g/day, respectively), hip height increase (1.45±0.33 vs. 1.70±0.31 cm/week for 0 and 40 g/d, respectively) and feed consumption (446.67±9.92 vs. 439.01±6.12 g/day for 0 and 40 g/d, respectively) were not affected by treatment (P>0.05). Odds ratios were calculated and the odds of a calf presenting with scours or pneumonia were 3.5 and 5.0, respectively, times more likely in the calves whose dams did not consume CEL prepartum. CEL supplementation prepartum improved colostrum quality and calf health.
Expresiones literarias de la cultura popular y el análisis de contenido
(1986) Cuevas Molina, Rafael; Chang Vargas, Giselle
Frecuencia de contaminación y resistencia a antibióticos en Salmonella aislada de carne de res en la región central de México
(2022-11) Campos Granados, Carlos Mario; Rubio Lozano, María Salud; Delgado Suárez, Enrique Jesús; Sánchez Zamorano, Luisa María
La salmonelosis transmitida por alimentos es un problema de salud pública a nivel global; con cerca de 80.3 millones de casos anuales. Se ha establecido que la carne de diferentes especies, entre ellas la de bovino, funciona como reservorio de su principal agente causal: Salmonella enterica subsp. enterica (SE). En México, la incidencia de salmonelosis en la última década (> 60 casos / 100 mil habitantes) es al menos tres veces superior a la de países desarrollados, lo que resalta la importancia epidemiológica de este patógeno en el país. Lo anterior cobra mayor relevancia ante el incremento de la resistencia a antimicrobianos (RAM) que se observa en varios agentes infecciosos, incluso en SE (Delgado-Suárez et al., 2021). Las cepas multirresistentes (MDR, por sus siglas en inglés) causan infecciones que son difíciles de tratar, por lo que pueden aumentar la carga de morbilidad, la cual es bastante alta en humanos. Debido al riesgo que representa el consumo de alimentos de origen animal, específicamente de carne de res, contaminados con SE resistente a antibióticos en México, en el presente trabajo se presentan datos sobre el perfil de resistencia fenotípica en cepas de SE aislada de carne de res en las capitales estatales de la zona centro de México. Esta información es de utilidad para identificar las clases de antibióticos que están perdiendo su efectividad contra SE, así como para el planteamiento de nuevas hipótesis de investigación encaminadas a identificar los factores genéticos involucrados en la RAM, su potencial de diseminación y las alternativas de control a tomar para contener el fenómeno de la RAM en patógenos transmitidos por alimentos.
How many species of Pleurothallidinae are there?
(2019) Pupulin, Franco; Bogarín Chaves, Diego Gerardo; Karremans Lok, Adam Philip
Subtribe Pleurothallidinae is possibly the most species-rich of all orchid groups. Nevertheless, they are a young group of plants in terms of scientific learning. The last three decades have been the most active with respect to taxonomic and systematic studies within the group, contributing an increasing rate of new taxa in the subtribe. Can a reasonable estimation of the real diversity of Pleurothallidinae be made at this time? We addressed the question through an analysis of the partial results of a 15-year study of the pleurothallid flora of Costa Rica. We summarized the main historical stages of the discovery of Pleurothallidinae richness and show how much it has changed our understanding of diversity as a consequence of more focused research. In 15 years the number of Pleurothallidinae increased from 433 species to 561 species (+30%). New taxa have been described in most of the pleurothallid genera recorded from Costa Rica, including Acianthera, Anathallis, Brachionidium, Dracula, Dresslerella, Echinosepala, Lepanthes, Masdevallia, Myoxanthus, Octomeria, Pabstiella, Platystele, Pleurothallis, Restrepiella, Trichosalpinx, Trisetella, Specklinia, and Stelis. The largest pleurothallid genera in Costa Rica are Lepanthes (with 150 species so far), Stelis (106 species), and Pleurothallis s.s. (51 species), three genera that we have not yet fully monographed. Projecting the trend observed in the genera and groups studied in more detail and mapping the collection effort carried out in Costa Rica, a further 300 new species of Pleurothallidinae could be expected. We can now estimate with some confidence that the total number of Pleurothallidinae for the flora of Costa Rica would exceed 800 species, and this means that roughly 2 of every 5 orchid species recorded in the country will be a pleurothallid. An updated checklist of Pleurothallidinae accepted for the flora of Costa Rica is presented, including 561 species in 30 genera. A new name and two new combinations are proposed in Stelis.
Improved pitch trajectory estimation for polyphonic single channel audio mixtures
(2016-12-20) Delgado Castro, Alejandro; Szymanski, John Edward
Estimating pitch trajectories for harmonic sources in single-channel polyphonic mixtures is a difficult task, especially when significant changes in volume and background instrumentation are present. A novel strategy is proposed to extract an improved and reliable dominant source pitch trajectory, based on one existing multipitch estimator, high-pass filtering, salience measurement and continuity.
Influencia de la campaña electoral 2014 presentada por Teletica sobre la intención de voto de la audiencia residente en la cabecera del cantón central de limón.
(2015) Araya Jiménez, Lisbeth; Elizondo Chaves, Noelia; Trejos Sánchez, Catalina; Trejos Vargas, Gabriel
Esta investigación pretendió hacer un aporte debido al vacío existente en el análisis reciente de la influencia mediática en materia electoral, su relación con la comunicación política y la importancia de ésta para de poblaciones fuera de la Gran Área Metropolitana, específicamente en el cantón central de Limón. Las y los investigadores están conscientes de la dificultad de aislar otra serie de influencias múltiples y diversas que inciden al mismo tiempo en la elección del voto, en consecuencia las preguntas del cuestionario se dirigen de manera directa a la opinión que al respecto tienen las y los encuestados. Para ello el estudio realizado se centró en lo presentado por la televisora Teletica en adelante denominado Contenido. Teletica junto con Repretel son los canales con mayor audiencia en el país (Sandoval, 2007). Adicionalmente se escoge Teletica por considerarlo uno de los mayores transmisores de propaganda política, debates y entrevistas.
Informe Biredial-SIBD 2013
(2013) Garro Acón, Meilyn
Informe ejecutivo de la conferencia Biredial-SIBD 2013. Contiene un resumen de los principales puntos organizativos de la conferencia, así como el programa de actividades.

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