Abstract The conservation of the soil resource represents a preventive measure in the adequate use for current and future populations, however, in recent years the impact of climate change is increasingly common; with damage are tangible and often difficult to overcome. Additionally, producers do not always have the tools and technical support to make a combined use of the productive practice with soil conservation and this prevents preventive actions in the face of accelerated soil erosion by water. In this article, two design proposals for soil conservation works are presented that seek to mitigate the damage present on a farm in San Pedro Tarrazú, Costa Rica, where the problem of gully-type soil erosion is found. Hydrological variables and characteristics of the soil under study were determined to calculate soil loss by means of the universal soil loss equation (RUSLE), resulting in an average soil loss of 20.54 tons per hectare per year. year. Hence, the implementation of the designed conservation works is the key to significantly reduce soil loss. These works consisted of the design of terraces, trap-type infiltration ditches, live barriers, contour crops and trees for shade and soil tying.

Resumen La conservación del recurso suelo, representa una medida de prevención en el aprovechamiento adecuado para las poblaciones actuales y futuras, sin embargo, en los últimos años es cada vez más común el impacto del cambio climático; con daños tangibles y muchas veces difíciles de superar. Adicionalmente, los productores no siempre cuentan con las herramientas y el soporte técnico para hacer un uso combinado de la práctica productiva con la conservación suelo y esto impide las acciones preventivas ante la acelerada erosión del suelo por el agua. En este artículo, se presentan dos propuestas de diseño de obras de conservación de suelo que buscan mitigar los daños presentes en una finca en San Pedro de Tarrazú, Costa Rica, donde se encuentra la problemática de erosión de suelo de tipo cárcava. Se determinaron variables hidrológicas y características del suelo en estudio para hacer el cálculo de pérdida de suelo por medio de la ecuación universal de pérdida de suelo (RUSLE), dando como resultado, una pérdida de suelo en promedio de 20,54 Toneladas por hectárea al año. De ahí que la implementación de las obras de conservación diseñadas son la clave para reducir la pérdida de suelo significativamente. Estas obras consistieron en el diseño de terrazas, zanjas de infiltración tipo trampa, barreras vivas, cultivos a contorno y árboles para sombra y amarre de suelo.

Resumen La eficiencia de las labores agrícolas mecanizadas incide en el rendimiento general de los cultivos y en la uniformidad de la producción, variables determinantes en la definición adecuada de las zonas de manejo diferenciado. Las pruebas de uniformidad de los implementos repercuten en la toma de decisiones para adquirir implementos y la administración de ellos. El objetivo de este trabajo es promover el uso eficiente de la maquinaria agrícola en el campo y evaluar las operaciones agrícolas para el uso adecuado de los recursos de producción. Se determinaron coeficientes de uniformidad del trabajo realizado con cada uno de los implementos probados, además otras variables operativas que influyen en el desempeño de ellas. Las labores más uniformes son las realizadas con implementos de labranza vertical (CU > 80%), aunque se conoce que demandan mayor potencia para romper la estructura del suelo, la sembradora volumétrica es más uniforme a velocidades de avance bajas (CU = 86,73%) y la pulverizadora presentó aplicaciones más homogéneas a bajas presiones de operación (CU = 98%). Las mediciones de uniformidad y actividades de calibración de los implementos permitieron identificar puntos críticos en la maquinaria, y fundamentar la importancia de determinarlos para la mejora continua de las operaciones agrícolas tendientes a lograr rendimientos del cultivo homogéneos.

Abstract The efficiency of mechanized agricultural work affects the general yield of crops and the uniformity of production, determining variables in the adequate definition of differentiated management areas. Implement consistency tests impact implement purchasing and implement management decisions. The objective of this work is to promote the efficient use of agricultural machinery in the field and to evaluate agricultural operations for the proper use of production resources. Uniformity coefficients of the work carried out with each of the implements tested were determined, as well as other operative variables that influence their performance. The most uniform tasks are those carried out with vertical tillage implements (CU > 80%), although they demand more power to break the soil structure, the volumetric seeder is more uniform at low speeds (CU = 86.73%) and the sprayer presented more homogeneous applications at low operating pressures (CU = 98%). The uniformity measurements and calibration activities of the implements allowed identifying critical points in the machinery, and substantiating the importance of determining them for the continuous improvement of agricultural operations aimed at achieving homogeneous crop yields.

Abstract The proximity of urban and extensive agricultural areas to the rivers of the Atlantic watershed in Costa Rica contrasts with its unstable morphology. Additionally, changes on the rain regime have increased the frequency of natural disasters affecting regularly the nearby populations and the economy of the country. Detailed studies demonstrating the impact of rivers in urban areas and high agricultural activity are necessary to establish adequate flood mitigation and control measures. The present study shows a case study of the impact of a 25-year flood event on the flood plain of the Matina River in Costa Rica, by means of a bi-dimensional hydraulic modelling with the aim to contribute to the adequate management of land use and the establishment of protection measures in the study vregion. A digital elevation model, of the topography of the study area, obtained with a LIDAR device, and the estimation of the instantaneous peak flow was obtained with the statistical Weibull distribution for a return period of 25 years, allowed to provide satisfactory information for the flood analysis of complex combinations for surface drainage management. Two scenarios for flood management were analyzed: 1) increasing the dike height, and 2) early opening of an additional mouth at the river outlet during the flood events. The study demonstrated that none of the options were technically feasible and that decision makers should explore other flood mitigation alternatives.

Resumen La proximidad de las áreas urbanas y de agricultura extensiva a los ríos de la vertientes del Atlántico en Costa Rica, contrasta con su morfología inestable. Adicionalmente, los cambios en el régimen de lluvias han incrementado la frecuencia de desastres naturales afectando regularmente a las población cercanas y la economía del país. Se necesitan estudios detallados que demuestren el impacto de los ríos en áreas urbanas y alta actividad agrícola para establecer medidas adecuadas de mitigación y control de inundaciones. El presente estudio muestra un caso del impacto de un evento de inundación de 25 años en la planicie de inundación del Río Matina en Costa Rica, mediante una modelación hidaúlica bidimensional con el objetivo de contribuir a un adecuado manejo del uso del suelo y establecer medidas de protección en la zona de estudio. Un modelo de elevación digital, de la topografía del área de estudio, obtenido con un dispositivo LIDAR, y la estimación del caudal pico instantáneo se obtuvo con la distribución estadística de Weibull para un periodo de retorno de 25 años, permitiendo brindar información satisfactoria para para el análisis de inundaciones de combinaciones complejas para la gestión del drenaje superficial. Se analizaron dos escenarios para el manejo de inundaciones: 1) aumento de la altura del dique y 2) apertura anticipada de una desembocadura adicional en la desembocadura del río durante los eventos de inundación. El estudio demostró que ninguna de las opciones era técnicamente factible y que los tomadores de decisiones deberían explorar otras alternativas de mitigación de inundaciones.

Resumen En Costa Rica el caudal ambiental se calcula como un 10% del aforo caudal medio del río. Este porcentaje ha carecido de fundamento científico en relación con las condiciones fluviales aptas para preservar los ecosistemas presentes en los cauces. Las concesiones de agua para los diferentes usos han provocado un impacto ambiental que se ve reflejado en las condiciones de disponibilidad del recurso hídrico y en las condiciones fisicoquímicas y ecológicas de los cauces. Este estudio responde a la ruta de investigación que busca la selección y validación en campo de diferentes metodologías para obtener el caudal ambiental requerido en una fuente de agua superficial. En este caso, el estudio está centrado en la adaptación y validación de una metodología hidrobiológica de cálculo del régimen de caudal ambiental en la cuenca del río Pejibaye en Jiménez de Cartago. Se utilizaron series de datos históricas de variables hidrológicas para analizar la condición actual y proyectada a futuro, se seleccionaron especies de macroinvertebrados y peces que permitieran evaluar la calidad de los ecosistemas asociados, finalmente se establecieron los parámetros hidráulicos de preferencia de hábitat para definir el régimen de caudal ambiental actual, cuyos resultados revelan un comportamiento de estacionalidad, el cual se acentúa en la proyección a futuro. Se determinó que el género de insecto Anacroneuria y la especie de pez G. nudus, son los mejores para determinar caudales ambientales.

Abstract The environmental flow, in Costa Rica, is calculated as 10% of the average flow of the river. This percentage has lacked scientific basis in relation to the river conditions suitable for preserving the ecosystems present in the rivers. The water concessions for the different uses have caused an environmental impact that is reflected in the conditions of availability of the water resource in some vulnerable points of the country, as well as in the physicochemical and ecological conditions of the channels. The proposed project responds to the research route that seeks the selection and field validation of different methodologies to obtain the required environmental flow in a surface water source. In this particular case, the project is focused on the adaptation and validation of a hydrobiological methodology for calculating the environmental flow regime in Pejibaye river basin, Jiménez de Cartago. Historical hydrological data variables were used to analyze the current and projected future condition, the species of macroinvertebrates and fish that allowed evaluating the quality of the associated ecosystems were selected, finally, the hydraulic parameters of habitat preference were established to define the current environmental flow regime, whose results reveal a seasonality behavior, which is accentuated in the future projection. The insect genus Anacroneuria and the fish species G. nudus were determined to be the best for determining environmental flows.

RESUMO Introdução: A síndrome congênita do zika envolve alterações estruturais do cérebro, incluindo ventriculomegalia, córtices finos do cérebro, padrão giral anormal, malformações corticais, hipoplasia do corpo caloso, atraso de mielinização, calcificações difusas subcorticais, hipoplasia do tronco cerebral e microcefalia em recém-nascidos. Objetivo: Este estudo teve como objetivo descrever as características clínicas de crianças com síndrome congênita do zika; comparar os resultados de bebês infectados no primeiro (1T, n=20) e no segundo trimestres da gravidez (2T, n=11); investigar correlações entre peso ao nascer, perímetro cefálico ao nascer e acompanhamento, idade gestacional ao nascer e escores motores brutos. Método: Os participantes foram avaliados com a Escala Motora Infantil de Alberta (Alberta Infant Motor Scale - AIMS) e a parte A da Medida da Função Motora Grossa (Gross Motor Function Measure - GMFM-A). A ANOVA comparou a circunferência da cabeça, a idade gestacional ao nascer, o peso ao nascer e o desempenho motor bruto de 1T e 2T. As correlações foram investigadas pelos coeficientes de correlação de Pearson. A ANOVA mostrou diferenças no perímetro cefálico ao nascimento e acompanhamento. A circunferência da cabeça foi menor no 1T, em comparação ao 2T. Resultados: O desempenho motor foi classificado como abaixo do quinto percentil na AIMS para todas as crianças e o 1T apresentou escores mais baixos na posição de bruços, sentado e no escore total da AIMS, em comparação ao 2T. As crianças variaram de 8 a 78% no GMFM-A e houve um desempenho motor pior de 1T. Dezenove crianças apresentaram hipertonia, seis apresentaram tônus normal e seis apresentaram hipotonia. A circunferência da cabeça no nascimento foi correlacionada com o controle postural em posição de bruços à AIMS. Discussão: O perímetro cefálico de acompanhamento foi correlacionado aos escores AIMS em posição de bruços, em supino e no escore total. Menor perímetro cefálico ao nascimento e acompanhamento indicaram pior controle postural. Crianças com síndrome congênita do zika apresentaram microcefalia ao nascimento e acompanhamento. Circunferências da cabeça menores e piores resultados motores foram observados no 1T. Os bebês apresentaram maus resultados visuais e motores. Foram encontradas correlações moderadas positivas entre o nascimento e a circunferência da cabeça de acompanhamento, e a função motora grossa.

ABSTRACT Background: The congenital Zika syndrome involves structural brain changes, including ventriculomegaly, thin cerebral cortices, abnormal gyral pattern, cortical malformations, hypoplasia of the corpus callosum, myelination delay, subcortical diffuse calcifications, brainstem hypoplasia, and microcephaly in newborns. Objective: This study aimed to describe the clinical characteristics of children with congenital Zika syndrome; to compare the outcomes of infants infected in the first (1T, n=20) and second trimesters of pregnancy (2T, n=11); to investigate correlations between birth weight, birth and follow-up head circumference, birth gestational age, and gross motor scores. Methods: Participants were evaluated with Alberta Infant Motor Scale (AIMS) and part A of the Gross Motor Function Measure (GMFM-A). ANOVA compared head circumference, birth gestational age, birth weight, and gross motor performance of 1T and 2T. Results: The correlations were investigated by Pearson correlation coefficients. ANOVA showed differences in birth and follow-up head circumferences. Head circumference was smaller in 1T, compared to 2T. Motor performance was classified as below the fifth percentile in AIMS in all children and 1T showed lower scores in prone, sitting, and total AIMS score, compared to 2T. Children ranged from 8 to 78% on GMFM-A and there was a poorer motor performance of 1T. Nineteen children showed hypertonia, six showed normal tone and six showed hypotonia. Birth head circumference was correlated with AIMS prone postural control. Follow-up head circumference was correlated to prone, supine and total AIMS scores. Smaller head circumference at birth and follow-up denoted poorer postural control. Discussion: Children with congenital Zika syndrome showed microcephaly at birth and follow-up. Smaller head circumferences and poorer motor outcomes were observed in 1T. Infants showed poor visual and motor outcomes. Moderate positive correlations between birth and follow-up head circumference and gross motor function were found.

Resumen En la cuenca del río La Estrella la deforestación en las partes altas y bajas del río, han debilitado la capacidad de retención de material de la cuenca, aumentando la frecuencia y capacidad destructiva de las descargas extremas. Adicionalmente, el terremoto de Limón en el año 1991, provocó una alteración geológica especialmente en el Valle La Estrella, modificando la dinámica tradicional y estabilidad de su cauce. Específicamente, el sector de río objeto de este estudio presenta dos agravantes: un asentamiento y la única vía de acceso terrestre muy cerca del cauce, lo que significa mayor riesgo para el poblado y en consecuencia es necesario realizar obras de protección. Para esto, se han comparado los resultados de los modelos hidráulicos en 1D y 2D con el fin de evidenciar la importancia de la información y su análisis para la toma de decisiones en lo referente al diseño de obras en el río.

Abstract In the basin of La Estrella River, deforestation in the upper and lower parts of the river has weakened the capacity for material retention of the basin, increasing the frequency and destructive capacity of extreme discharges. Additionally, the Limon earthquake of 1991 caused geological disturbance, especially in La Estrella Valley, modifying the traditional dynamics and stability of its river channel. Specifically, one river section which is the object of this study shows two aggravating circumstances: a human settlement and the location of the only access road to that settlement very near the river channel, implying higher risk for the settlement and the need to implement protection works. We have therefore compared the results of hydraulic 1D and 2D models to demonstrate the importance of information and its analysis for making decisions about the design of these protection and mitigation works in the river.

Resumen En Costa Rica el caudal ambiental se calcula como un 10% del aforo caudal medio del río. Este porcentaje ha carecido de fundamento científico en relación con las condiciones fluviales aptas para preservar los ecosistemas presentes en los cauces. Las concesiones de agua para los diferentes usos han provocado un impacto en disponibilidad de agua para algunos lugares y épocas del año y en la calidad del recurso transformando las condiciones fisicoquímicas y ecológicas de los cauces. Del sistema fluvial del río Birrís, se concesiona un 20% para uso consuntivo como producción agrícola, humano y riego, y el restante se utiliza para la generación hidroeléctrica. Debido a la baja calidad de sus aguas a la fecha no existen especies indicadoras lo que imposibilita el uso de enfoques que tomen en cuenta los ecosistemas para generar curvas de preferencia. El presente trabajo utilizó un enfoque hidrológico para determinar el caudal ambiental del río Birrís usando la metodología de curva de duración de caudales. Se basó en el análisis de series de datos de clima obtenidas por 10 años y series de caudales diarios de un periodo de tres años. Se realizaron tres aforos de biota y flujo en tres puntos distribuidos a lo largo del cauce principal distribuidos en un periodo de un año. Finalmente, se determinó el caudal ambiental para un régimen de flujo basado en valores medios mensuales.

Abstract In Costa Rica, the environmental flow corresponds to 10% of the average river flow. This percentage has lacked of scientific basis in relation to the fluvial conditions suitable for preserving the ecosystems present in the river. Water concessions for the main uses (human, agricultural and hydroelectric) have caused environmental damages, transforming the physical and chemical conditions of the channels. Of the water flow of the Birrís River, 20% is granted for consumptive use as agricultural, human and irrigation production, and the rest is used for hydroelectric generation. Due to the low quality of its waters to date there are no indicator species that makes it impossible to use approaches that take into account ecosystems to generate preference curves. The present work used a hydrological approach to determine the environmental flow of the Birrís River using the flow duration curve methodology. It is based on the analysis of series of climate data obtained for 10 years and series of daily flows from a period of three years. Three outflows of biota and flow were made in three points distributed along the main channel distributed over a period of one year. Finally, the environmental flow was determined based on the flow regime of the average monthly values.

Abstract Soil salinity is one of the most devastating problems which reduces crop production and increases desertification. New approaches to overcome the negative effect of salinity on plants include the use of plant biostimulants, such as Xyloglucan oligosaccharides (XGOs) derived from the breakdown of xyloglucans from plant cell walls. The present study aimed at verifying the influence of exogenous XGOs derived from Tamarindus indica L. cell walls, on Arabidopsis thaliana’s tolerance to salt stress by understanding the gene expression, enzymatic and metabolic changes resulting from its application. A. thaliana plants were grown in liquid media and after 15 days they were treated by a salt shock with 100 mM of sodium chloride, with or without XGOs at 0.1 mg L-1. Gene expression of four oxidative stress markers as well as catalase and peroxidase activities and content of glutathione, total carbonyl, polyphenolics and chlorophyll were quantified. Bioinformatic models were used to obtain the co-expression network of the four oxidative stress response gene markers from microarray data of Arabidopsis under salt stress. Results showed that in saline conditions, XGOs dramatically increased catalase gene expression and enzymatic activity, peroxidase activity, and chlorophyll a/b ratio, while reducing protein oxidation and total polyphenols. Thus, XGOs may act to counteract negative effects of oxidative stress under saline conditions.

RESUMO Terapias regenerativas vem sendo amplamente desenvolvidas na odontologia e o conhecimento destas novas terapias por parte dos dentistas é importante para que elas sejam incorporadas na rotina clínica odontológica. Assim, este estudo revisou a literatura acerca das terapias regenerativas e suas aplicações clínicas. A engenharia tecidual tem contribuído na mudança do paradigma restaurador das ciências da saúde. Seus pilares embasam as técnicas de regeneração de tecidos e órgãos. Apesar da grande maioria dos estudos neste campo ser in vitro, uma gama de metodologias pré-clínicas foi consolidada e estudos utilizando estes princípios já estão sendo empregados em humanos. A utilização de plasma rico em plaquetas e plasma rico em fibrina como scaffolds naturais em cirurgias para reestabelecimento de tecido ósseo e periodontal são frequentemente relatadas na literatura e ensaios clínicos utilizando esta abordagem demonstram resultados promissores. Células-tronco da polpa dental autólogas já foram aplicadas com sucesso na regeneração de tecido ósseo utilizando scaffold naturais de colágeno em humanos. Além disto, a revascularização do canal radicular já aparece na literatura como uma alternativa promissora frente a opção de apecificação do canal radicular. Esta terapia utiliza como princípio o coágulo sanguíneo como scaffold e a migração das células-tronco da papila apical para regenerar o órgão pulpar. Considerações finais: Apesar de incipientes, as terapias regenerativas já podem ser utilizadas na prática clínica odontológica. O conhecimento dos princípios que regem estas terapias deve ser compreendido pelo dentista para que sejam utilizadas na prática clínica.

ABSTRACT Regenerative therapies have been widely developed in dentistry and it is important to incorporate dentists’ knowledge of these new therapies into the dental clinic routine. This study reviewed the literature on regenerative therapies and clinical applications. Tissue engineering has contributed to changes in the paradigm of restorative health sciences. Its pillars underpin the techniques of tissue and organ regeneration. Despite the majority of studies in this field being in vitro, a range of preclinical studies and methodologies has been formed using these principles and they are already being used on humans. The use of platelet-rich plasma and platelet-rich fibrin in surgery as natural scaffolds for the reestablishment of bone and periodontal tissue are often reported in the literature and clinical trials using this approach have shown promising results. Stem cells from autologous dental pulp have been successfully applied in bone tissue regeneration using natural collagen scaffold in humans. In addition, revascularization of the root canal already appears in the literature as a promising alternative to apexification. The principle behind this therapy is the use of the blood clot as a scaffold and the migration of stem cells of the apical papilla to regenerate the dental pulp organ. Final considerations: Although still in the early stages, regenerative therapies can now be used in dental practice. Knowledge of the principles governing these therapies should be understood by the dentist for use in clinical practice.