AFINET: agroforestry innovation thematic network

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Post-encoding stress does not enhance memory consolidation: The role of cortisol and testosterone reactivity

In contrast to the large body of research on the effects of stress-induced cortisol on memory consolidation in young people, far less attention has been devoted to understanding the effects of stress-induced testosterone on this memory phase. This study examined the psychobiological (i.e., anxiety, cortisol, and testosterone) response to the Maastricht Acute Stress Test and its impact on free recall and recognition for emotional and neutral material. Thirty-seven healthy young men and women were exposed to a stress (MAST) or control task post-encoding, and 24 h later, they had to recall the material previously learned. Results indicated that the MAST increased anxiety and cortisol levels, but it did not significantly change the testosterone levels. Post-encoding MAST did not affect memory consolidation for emotional and neutral pictures. Interestingly, however, cortisol reactivity was negatively related to free recall for negative low-arousal pictures, whereas testosterone reactivity was positively related to free recall for negative-high arousal and total pictures. This study provides preliminary evidence about a different reactivity of testosterone and cortisol to the MAST as well as on their effects on consolidation. Our results suggest a different pattern of relationships between these steroid hormones and the arousal of the negative images

Effects of sex and menstrual cycle phase on cardiac response and alpha- amylase levels in psychosocial stress

The impact of sex and the menstrual cycle phase on the autonomic response to psychosocial stress remains controversial. This study explored autonomic nervous system activity through salivary alpha-amylase, heart rate, and heart rate variability responses to the Trier Social Stress Test (TSST) in healthy young people. The sample was composed of 25 men, 26 women in the luteal phase, and 25 women in the follicular phase, from 18 to 25 years of age. Participants were exposed to the TSST or a control condition. The results indicate that women in their follicular phase showed a blunted alpha-amylase response to stress compared to men and women in the luteal phase. In addition, men showed higher sympatho-vagal activity in the stress condition compared to the two groups of women. These results confirm that sex and the menstrual cycle phase are potential modulators of autonomic nervous system reactivity to psychosocial stress

Differences between semantic profiles of the action tendencies linked to emotion words in achievement and unspecified general contexts, defined by Colombian spanish native speakers

Introduction. We investigated the meaning of sixteen achievement emotion words —anger, anxiety, boredom, contentment, despair, disappointment, frustration, guilt, hope, hopelessness, joy, pride, relief, sadness, shame, and surprise—, specifically in terms of their action tendencies component, through a modified version of the CoreGRID questionnaire. Our aim was to identify in which cases the achievement context modifies the semantic profiles of each emotion word, specifically in terms of their action tendencies component, as compared to an unspecified general context.Method. Forty-one participants (22 females; Mage = 21.8, SD = 3.5), and another group of thirty-six participants (21 females; Mage = 20.42, SD = 2.8), rated the likelihood of eighteen action tendencies to be part of the meaning of each emotion word in an achievement context condition and in a general context condition, respectively.Results. In both conditions, Cronbach’s Alpha ranged from 0.95 to 0.98. Data analysis revealed statistically significant differences for every emotion investigated, suggesting an influence of context in their semantic profile.Discussion. The discussion of these results is centered mainly around data from other studies that were interested in the motivational component of emotions, since there is a lacking of research on semantic profiles of achievement emotions. Finally, we make suggestions on directions for future research and inform of the limitations of our study.</jats:p

Use of rice husk for the removal of methylene blue in fixed-bed columns

Este trabajo muestra la utilización de la cascarilla de arroz para la remoción del colorante catiónico azul de metileno bajo sistema continuo. Un diseño factorial 23, con puntos centrales y distribución aleatoria, fue implementado para evaluar la correlación de los factores experimentales en el proceso de adsorción. Las variables consideradas fueron pH, tamaño de partícula, presencia salina, velocidad de entrada, concentración inicial del colorante y altura de columna. Las muestras fueron analizadas a intervalos definidos de tiempo. La cantidad del colorante removido fue cuantificado por medio de espectroscopia Ultravioleta - Visible. Los modelos de Adams-Bohart, Thomas y BDST (Bed-depht/service time analysis) fueron utilizados para predecir las curvas de ruptura usando regresión no lineal y establecer los parámetros característicos del proceso. Se encontró que la transferencia de colorante al material adsorbente se favorece a pH básico, menor tamaño de partícula, flujo y concentración baja y mayor altura. El diseño de experimentos estableció que la concentración inicial de colorante y la altura del lecho fueron los factores más significativos. Con respecto a los modelos, el de Thomas presentó el mejor ajuste para la descripción de las curvas de ruptura a las condiciones experimentales y el de Adams-Bohart resultó adecuado para el comportamiento dinámico limitado a la parte inicial. Finalmente, el modelo BDST mostró una buena correlación y permitió establecer que la altura es determinante para el escalado del proceso.This work shows the use of rice husk in the removal of cationic dye methylene blue on continuous system. A factorial design 23 with center points and random distribution was implemented to evaluate the correlation of the experimental factors in the adsorption process. The considered variables were pH, particle size, salt presence, flow rate, dye initial concentration, and bed depth. The samples were analyzed in defined time intervals. The amount of removed dye was quantified by UV spectroscopy - Visible. Adams-Bohart, Thomas and BDST (Bed-depht/service time analysis) models were used to predict the breakthrough curves using non-linear regression and establish the characteristic parameters of the process. It was found that the transference of dye toward the adsorbent is favored by a basic pH, a small particle size, low flow rate and dye concentration, and high bed depth. The design of experiments established that the initial dye concentration and the bed depth were the most significant factors. Regarding the models, the Thomas provided the best fit to describe the breakthrough curves in experimental conditions and Adams-Bohart was found suitable for dynamic behavior limited to the initial part. Finally, BDST model exhibited a good correlation and allowed to establish that bed depth is a determinant factor for scaling process

Food packaging-interactions: migration

Foodstuffs quality and safety are important issues involving packaging behavior in food preparing and storing processes. In this context, food legislation compliance increasingly demanding, concerns the knowledge of several key aspects of food-packaging systems. This article presents a review about main packaging materials currently used in the food in­dustry, their interactions with the packaged product, mainly migration of macro and microelements from packaging to food, analytical techniques and mathematical models used in elements migrants identification, the national and international regulations established.La calidad e inocuidad de los productos alimenticios es un tema relevante que involucra el comportamiento de los empaques en los procesos de preparación y almacenamiento de alimentos. En este contexto, el cum­plimiento de la legislación alimentaria, cada día más exigente, requiere el conocimiento de varios aspectos clave en los sistemas empaque-alimento. Este artículo presenta una revisión acerca de los principales materiales de empaque actualmente usados en la industria alimentaria, sus interaccio­nes con el producto empacado principalmente la migración de macro y microelementos desde el empaque hacia el alimento, abordando técnicas analíticas y modelos matemáticos usados en la identificación de elemen­tos migrantes, así como también aspectos relacionados con la normativa establecida nacional e internacionalmente

Phenomenology of a three-family model with gauge symmetry SU(3)_c X SU(4)_L X U(1)_X

We study an extension of the gauge group SU(3)_c X SU(2)_L X U(1)_Y of the standard model to the symmetry group SU(3)_c X SU(4)_L X U(1)_X (3-4-1 for short). This extension provides an interesting attempt to answer the question of family replication in the sense that models for the electroweak interaction can be constructed so that anomaly cancellation is achieved by an interplay between generations, all of them under the condition that the number of families must be divisible by the number of colours of SU(3)_c. This method of anomaly cancellation requires a family of quarks transforming differently from the other two, thus leading to tree-level flavour changing neutral currents (FCNC) transmitted by the two extra neutral gauge bosons $Z'$ and $Z''$ predicted by the model. In a version of the 3-4-1 extension, which does not contain particles with exotic electric charges, we study the fermion mass spectrum and some aspects of the phenomenology of the neutral gauge boson sector. In particular, we impose limits on the $Z-Z'$ mixing angle and on the mass scale of the corresponding physical new neutral gauge boson $Z_2$, and establish a lower bound on the mass of the additional new neutral gauge boson $Z'' \equiv Z_3$. For the analysis we use updated precision electroweak data at the Z-pole from the CERN LEP and SLAC Linear Collider, and atomic parity violation data. The mass scale of the additional new neutral gauge boson $Z_3$ is constrained by using updated experimental inputs from neutral meson mixing in the analysis of the sources of FCNC in the model. The data constrain the $Z-Z'$ mixing angle to a very small value of O(0.001), and the lower bounds on $M_{Z_2}$ and on $M_{Z_3}$ are found to be of O(1 TeV) and of O(7 TeV), repectively.Comment: 22 pages, 6 tables, 1 figure. To appear in J. Phys. G: Nuclear and Particle Physic

Population structure of two species of Dichotomius Hope, 1838 (COLEOPTERA: SCARABAEINAE) in a coffee landscape of the western andes of Colombia, Risaralda

Los escarabajos coprófagos son un grupo de insectos ampliamente reconocido como indicador ecológico de perturbación antrópica, por lo cual cuentan con una gran cantidad de información a nivel de los ensamblajes. En contraste, aún son escasos los estudios a nivel poblacional y apenas se ha empezado a entender cómo la fragmentación y transformación de sus hábitats afecta la estructura y dinámica de las poblaciones de Scarabaeinae. En este trabajo se examinaron algunos aspectos sobre la estructura poblacional de dos especies de Scarabaeinae típicas del paisaje cafetero en los Andes occidentales de Colombia (Dichotomius&amp;nbsp;cf.&amp;nbsp;satanas&amp;nbsp;y&amp;nbsp;D. cf.&amp;nbsp;alyattes). Entre agosto de 2010 y febrero de 2011, en dos localidades cafeteras de Risaralda, se instalaron seis transectos de ecotono cada uno compuesto por 15 trampas de caída no letales cebadas con una mezcla de excremento humano y cerdo. Cada mes las trampas estuvieron activas durante 48 horas, con revisión cada 24 horas. En cada revisión los especímenes de ambas especies se marcaron con el método de perforaciones en los élitros. Se marcaron 1723 individuos, de los cuales 73 fueron recapturados (43 de&amp;nbsp;D. cf.&amp;nbsp;alyattes&amp;nbsp;y 30 de&amp;nbsp;D. cf.&amp;nbsp;satanas). El tamaño poblacional estimado fue diferente entre especies y localidades, así como la densidad promedio osciló entre 26,4 y 172,2 ind/km². Ambas especies presentaron una proporción de los sexos similar (∼1:1) y mostraron diferencias en sus preferencias de hábitat:&amp;nbsp;D. cf.&amp;nbsp;satanas&amp;nbsp;tendió a mantenerse en el interior del bosque; mientras que&amp;nbsp;D. cf.&amp;nbsp;alyattes&amp;nbsp;usa de forma extensiva el ecotono bosque – café de sol.Dung beetles are a group of insects widely recognized as ecological indicators of anthropic disturbance, reason why they count with a lot of information at the level of the assemblies. In contrast, population-based studies are still scarce and little has been understood on how fragmentation and transformation of their habitats affect the structure and dynamics of Scarabaeinae populations. Some aspects of the population structure of two typical Scarabaeinae species (Dichotomius&amp;nbsp;cf.&amp;nbsp;satanas&amp;nbsp;and&amp;nbsp;D. cf.&amp;nbsp;alyattes) of the coffee landscape in the Western Andes of Colombia are examined in this paper. Between August 2010 and February 2011, six ecotone transects, each one consisting of 15 non-lethal pitfall traps, primed with a mixture of human and pig excrement, were installed in two coffee growing locations of Risaralda. Each month the traps were active for 48 hours and were inspected every 24 hours. Specimens of both species were labeled with the elytron drilling method in each inspection. A total of 1723 individuals were marked of which 73 were recaptured (43&amp;nbsp;D. cf.&amp;nbsp;alyattes&amp;nbsp;and 30&amp;nbsp;D. cf.&amp;nbsp;satanas). The estimated population size differed between species and locations, and the average density ranged between 26.4 and 172.2 ind/km². Both species had similar gender ratio (∼1:1) and showed differences in their habitat preferences:&amp;nbsp;D. cf.&amp;nbsp;satanas&amp;nbsp;tended to stay inside the forest, while&amp;nbsp;D. cf.&amp;nbsp;alyattes&amp;nbsp;used extensively ecotone forest – sun coffee

Investigación y desarrollo tecnológico en la Unión Europea

Se trata la función que ha de tener la Documentación en el ámbito de la Publicidad y las Relaciones Poeblicas ante la generalización del uso de Internet, especialmente en lo que se refiere a las páginas Web. Se entiende que, dados el flujo de información y los nuevos avances tecnológicos, es necesaria una revisión teórica sobre el particular

Kinetics for the biodiesel production from lauric acid over Keggin heteropolyacid loaded in silica framework

Kinetic models were developed to describe the esterification reaction of lauric acid and ethanol over heterogeneous catalysts, which is a reaction of special interest in the biodiesel production. Vanadium Keggin heteropolyacid was included on a silica framework by sol–gel procedure, using different loadings. The synthesized materials were characterized by FT-IR, XRD, SEM, nitrogen adsorption/desorption isotherms, and potentiometric titration, and tested as solid catalysts in the esterification of lauric acid. Best performance was achieved with SiO2@20PMoV, which was used in the esterification of others fatty acid and alcohols. The reuse was successfully tested in five consecutive runs. Kinetic data using SiO2@20PMoV were obtained at different temperatures (48–78 °C), fatty acid:alcohol molar ratios (4 mmol of lauric acid and 2.5, 5, 10 and 15 mL of ethanol), and catalyst amounts (12.5, 25 and 50 mg). The best heterogeneous models were LH3 (surface reaction as rate-limiting step) and ER3 (desorption of ethyl laurate as rate-limiting step when the adsorbed reactant is lauric acid). The activation energies were 56.1 kJ mol−1 and 64.8 kJ mol−1, and the reaction rate constants at 78 °C were 0.2791 mol g−1 h−1 and 0.0768 mol g−1 h−1 for LH3 and ER3, respectively.Fil: Gallego Villada, Luis A.. Universidad de Antioquia; ColombiaFil: Alarcón Durango, Edwin Alexis. Universidad de Antioquia; ColombiaFil: Palermo, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Vazquez, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin