Factores que determinan la colonización de insectos acuáticos en pequeños estanques

Factors determining insect colonization of small artificial ponds. Insect colonization was studied in a set of ten small experimental ponds of same size, subjected to different environmental conditions. Correspondence Analysis was employed to analyze the effect of some environmental and life history variables on settlement of insect taxa. The analysis distinguished two groups of species: 1) generalist species that colonized all the ponds studied (except pond X), independently of environmental conditions, and 2) selective species that colonized only some ponds. Among the environmental variables studied, vegetation, substrate, salinity and insolation degree, were important determinants of habitat selection by species. Taxa showed differences in colonization ability based mainly on feeding strategies more than on flight capacity.Se estudió la colonización por insectos de una serie de diez pequeños estanques experimentales de igual tamaño, sometido a distintas condiciones ambientales. Se empleó un análisis de correspondencias para analizar el efecto de algunas variables ambientales y del ciclo biológico sobre la instalación de los táxones de insectos. El análisis distinguió dos grupos de especies: 1) especies generalistas que colonizaron todos los estanques estudiados (excepto el X), con independencia de las condiciones ambientales, y 2) especies selectivas que sólo colonizaron algunos estanques. Entre las variables ambientales estudiadas, las que resultaron importantes para la selección del hábitat por parte de las especies fueron: vegetación, sustrato, salinidad y grado de insolación. Los distintos táxones mostraron diferencias en la capacidad de colonización basadas principalmente en las estrategias alimentarias más que en la capacidad de vuelo

EL CLIMA DE LA CUENCA DEL RIO SEGURA (S.E. DE ESPANA): FACTORES QUE LO CONTROLAN

The termopluviometrical data of 65 meteorological stations located in the Basin of the Segura River (S.E. of Spain) have been used to characterize homogeneus climatic sectors. The statistical analysis of the information was carried out in different phases and on separate matrices. To detect the possible effects of two different environmental factors (the altitude above the sea level and the proximity to the sea) on the basin climate, we have employed a step by step multiple linear regression analysis. The results suggest the existence of termopluviometrical gradients where ten different climatic sectors can be identified. A few of these sectors seem to function as «islands».Se han empleado los datos termopluviométricos de 65 estaciones meteorológicas localizadas en la Cuenca del Segura (S.E. de España), para caracterizar sectores climáticos homogéneos en la misma. El análisis de la información se llevó a cabo en varias fases y sobre distintos tipos de matrices, aplicando técnicas estadísticas de ordenación. Para detectar las posibles influencias que, sobre el clima de la cuenca, ejercen dos factores del medio físico: altitud y proximidad al mar, se aplicó un análisis de regresión lineal múltiple paso a paso («stepwise multiple linear regression»). Los resultados obtenidos permiten definir diez tipos de sectores climáticos, a modo de gradientes termopluviométricos, donde destacan algunos que funcionan como «islas», de notable peculiaridad e interés ambiental

Genotyping and differential bacterial inhibition of Batrachochytrium dendrobatidis in threatened amphibians in Costa Rica

Amphibians have declined around the world in recent years, in parallel with the emergence of an epidermal disease called chytridiomycosis, caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd). This disease has been associated with mass mortality in amphibians worldwide, including in Costa Rica, and Bd is considered an important contributor to the disappearance of this group of vertebrates. While many species are susceptible to the disease, others show tolerance and manage to survive infection with the pathogen. We evaluated the pathogen Bd circulating in Costa Rica and the capacity of amphibian skin bacteria to inhibit the growth of the pathogen in vitro. We isolated and characterized – genetically and morphologically – several Bd isolates from areas with declining populations of amphibians. We determined that the circulating chytrid fungus in Costa Rica belongs to the virulent strain Bd-GPL- 2, which has been related to massive amphibian deaths worldwide; however, the isolates obtained showed genetic and morphological variation. Furthermore, we isolated epidermal bacteria from 12 amphibian species of surviving populations, some in danger of extinction, and evaluated their inhibitory activity against the collection of chytrid isolates. Through bioassays we confirmed the presence of chytrid-inhibitory bacterial genera in Costa Rican amphibians. However, we observed that the inhibition varied between different isolates of the same bacterial genus, and each bacterial isolation inhibited fungal isolation differently. In total, 14 bacterial isolates belonging to the genera Stenotrophomonas, Streptomyces, Enterobacter, Pseudomonas and Klebsiella showed inhibitory activity against all Bd isolates. Given the observed variation both in the pathogen and in the bacterial inhibition capacity, it is highly relevant to include local isolates and to consider the origin of the microorganisms when performing in vivo infection tests aimed at developing and implementing mitigation strategies for chytridiomycosis.United States Fish and Wildlife Service/[46-6003541]/USFWS/Estados UnidosUniversidad de Costa Rica/[801-B2-029]/UCR/Costa RicaUniversidad de Costa Rica/[810-B7-A46]/UCR/Costa RicaMinisterio de Ciencia, Tecnología y Telecomunicaciones/[849-PINN-2015-I]/MICITT/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM

Antioxidant activity and characterization of whey protein-based beverages: Effect of shelf life and gastrointestinal transit on bioactivity

Whey proteins can exhibit antioxidant activity. The objectives of this study were to formulate model whey based beverages with well-established antioxidants (plant polyphenols, vitamins and astaxanthin) to investigate (1) the antioxidant shelf life over a 24-week period and (2) the antioxidant activity after upper gastrointestinal transit. Pilot scale processing (pasteurization, ultra-high temperature or spray drying) was used to prepare beverages which were representative of current product formats. In vitro gastrointestinal digestion of test samples was performed using the standardised INFOGEST method and antioxidant activity of samples was determined using ABTS, FRAP and ORAC. Results from the antioxidant shelf life study provided evidence that powder products functionality was preserved. Whey beverages (pasteurised or spray dried) increased or maintained antioxidant activity during gastrointestinal transit. Combination of whey with additional antioxidant ingredients increased the bioactivity of formulated products; however, this greater bioactivity was altered after gastrointestinal transit, depending on processing type and antioxidant methodology. Industrial relevance: Whey protein-based antioxidant beverages could benefit the elderly consumer to meet their increased protein requirements and boost their antioxidant status. Consumer's acceptance for whey protein-based beverages often improves with clear formulations. This work generated whey protein-based UHT beverages with greater stability and clarity than pasteurised formulations. A novel combination of plant and marine antioxidants increased antioxidant activity of whey protein-based formulations. Furthermore, to suit export markets this work generated spray dried whey protein formulations that did not alter antioxidant potentialThis work was funded by the Irish Department of Agriculture, Food and the Marine, FIRM 13F354-WheyGSH and 15F604-TOMI). A. R. Corrochano was in receipt of a Teagasc Walsh Fellowship. E. Arranz also received funding from Enterprise Ireland (MF2018-0151) and the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 71365

Análisis del compromiso deportivo de jóvenes waterpolistas: Un estudio basado en la Teoría de la AutoDeterminación

Fundamentado en la Teoría de la Autodeterminación (TAD), el objetivo del estudio fue analizar la relación entre la percepción de jóvenes waterpolistas sobre el estilo interpersonal del entrenador, la satisfacción y frustración de sus necesidades psicológicas básicas (NPB), la motivación autodeterminada y su compromiso deportivo. Participaron 77 jugadores de waterpolo con una edad comprendida entre los 13 y los 20 años (M = 15.00, DT = 1.70). Los resultados mostraron que la percepción de los jugadores de un estilo de apoyo a la autonomía del entrenador, la satisfacción de las NPB, la motivación intrínseca y el compromiso deportivo se relacionaba positiva y significativamente, siguiendo la secuencia establecida en la TAD. En sentido contrario, el estilo controlador percibido por los jugadores se relacionaba positiva y significativamente con la frustración de las NPB y la desmotivación y negativamente con el compromiso deportivo. Los resultados destacan la importancia del estilo interpersonal del entrenador sobre los procesos motivacionales y el compromiso deportivo de los jóvenes waterpolistas. Grounded in Self-Determination Theory (SDT), the aim of this study was to analyze the relationship between waterpolo players perception on coach interpersonal style, satisfaction and frustration of their basic psychological needs (BPN), self-determined motivation and sport commitment. 77 male water polo players, with ages between 13 and 20 years old (M = 15.00, SD = 1.70), took part in the study. Results showed that players' perception of autonomy support coaching style was related positively and significantly with the satisfaction of BPN, intrinsic motivation and sport commitment, following established sequence in SDT. However, controlling coaching style was related positively and significantly with the frustration of BPN, amotivation and negatively with sport commitment. The results highlight the importance of coach interpersonal style on motivational processes and the sports commitment of young water polo players

Analysis of the Yield of Radish (Raphanus Sativus L.) Fertilized with Compost Based on Organic Waste from Markets and its Relationship with its Stomatal Density

For higher yields in vegetable cultivation, the availability of soil nutrients must be improved. Therefore, the aim of this research was to establish the relationship between stomatal density and the yield of the radish crop fertilized with compost made from organic market waste. A completely randomized block design was used, which consisted of 3 blocks and 5 treatments, which were T1, T2, T3, T4 and T5 with 00, 10, 15, 15, 20 and 25 g compost/plant respectively. The physical characteristics of the plants were evaluated from sowing to harvest and the data obtained were processed by analysis of variance and Duncan's test. Chemical analysis of the compost and soil was carried out, as well as a foliar analysis to determine the nutrient concentration by treatment. The results determined that the treatment (T4) stood out in plant length with 28.96 cm, plant weight with 43.33 g, yield of 10.82 t/ha and bulb diameter of 3.92 cm; likewise, in the concentration of nutrients in the leaves, the treatment (T5) highlighted in N with 5.94%, Ca 4.84%, Mg 1.29%, Zn 64.58 ppm and a stomatal density of 642 stomas/mm2. It is concluded that, at an adequate dose of compost, the concentration of nutrients increases, as well as the stomatal density, resulting in higher yields

DIGESTIÓN RUMINAL E INTESTINAL DEL MAÍZ (Zea mays) Y SORGO (Sorghum bicolor L. MOENCH) UTILIZANDO DIFERENTES TÉCNICAS DE DIGESTIBILIDAD (IN VIVO, IN VITRO E IN SACCO)

El conocimiento de la digestibilidad de los alimentos es básico para establecer su valor nutritivo y biodisponibilidad de los nutrientes para ello se han utilizado numerosos análisis de laboratorio para estimar la digestión ruminal e intestinal del alimento como son in vitro (Produccion de gas y Daisy ) e in sacco, para ser comparadas con el método in vivo. El sorgo presenta el mayor (P0.05) entre cereales. Con lo que respecta a los métodos de digestibilidad, la MSd fue menor (P0.01) para los métodos in sacco e in vitro (Daisy). La producción de AGV S fue similar para ambos cereales. Las técnicas in situ e in vitro (DaisyII ® ) permiten determinar la digestibilidad de forma rápida y sencilla comparado con los métodos convencionales. El molido del sorgo mejora su valor alimenticio aumentando su digestibilidad, lo que representa una alternativa ante el maíz para la alimentación de terneros en engorda