Search results for "Conducta"
showing 10 items of 611 documents
Does short-term potassium fertilization improve recovery from drought stress in laurel?
2014
Xylem hydraulic conductance varies in response to changes in sap solute content, and in particular of potassium (K(+)) ion concentration. This phenomenon, known as the 'ionic effect', is enhanced in embolized stems, where it can compensate for cavitation-induced loss of hydraulic conductance. Previous studies have shown that in well-watered laurel plants (Laurus nobilis L.), potassium concentration of the xylem sap and plant hydraulic conductance increased 24 h after fertilization with KCl. The aim of this work was to test whether water-stressed laurel plants, grown under low potassium availability, could recover earlier from stress when irrigated with a KCl solution instead of potassium-fr…
Dominància i ocupació de l'espai en grups de primats no-humans: un model basat en conducta adaptativa
2007
L'estructura jeràrquica és una de les característiques fonamentals de les societats de primats, que condiciona en gran mesura el comportament dels individus que conviuen al grup. Quines lleis regeixen la formació i l'estructura d'aquestes jerarquies? Per què en determinats grups els subjectes més dominants se situen al centre del grup i en uns altres de la mateixa espècie no? En el camp de la conducta animal s'han proposat múltiples hipòtesis, però no n'hi ha cap que siga totalment satisfactòria, ja que a causa de les múltiples variables que hi infl ueixen, és difícil desplegar una teoria que explique tota la complexitat que s'observa empíricament. La nostra proposta d'estudi es basa en l'e…
Sexism and romantic love myths in adolescents living in residential care
2021
La investigación explora la relación entre sexismo y la distorsión en mitos del amor romántico en adolescentes que residen en Centros de Acogida de Menores en Valencia (España). El diseño de investigación fue descriptivo transversal con una muestra de 147 adolescentes. Los resultados reflejan una relación estadísticamente significativa que indica que, a mayor sexismo en los y las adolescentes, mayores son las distorsiones románticas. Se identificaron mayores niveles de sexismo hacia las mujeres y mitos del amor romántico en chicos, mientras que las mujeres mostraron mayores puntuaciones en las actitudes sexistas hacia los hombres. Se concluye que la vivencia de situaciones de violencia fami…
La conducta prosocial como factor protector de los problemas de adicción al juego en universitarios
2020
espanolEsta investigacion busca analizar las variables implicadas en la conducta prosocial y la capacidad de esta para actuar como un factor protector frente a los problemas de adiccion al juego. Este estudio es de tipo cuantitativo, descriptivo, transversal y correlacional. La muestra se compuso por 258 adultos jovenes universitarios (59.5% mujeres) con una edad media de 20.95 anos (DE= 2.19). Se aplicaron cuestionarios (Brief Resilient Coping Scale, cuestionario de apoyo social, Escala de Prosocialidad y South Oaks Gambling Screen) para medir las variables implicadas y realizo un modelo de ecuaciones estructurales. Los resultados mostraron buenos indices de ajuste (X2(41)= 59.31, p= .06; …
Transpiration rates and hydraulic conductance of two olive genotypes with different sensitivity to drought
2019
Although some mechanisms of leaf dehydration tolerance are known in olive (Olea europaea L.), insights on adjustments in stem and root hydraulic conductance (K) in response to drought are yet to be explored. This work investigated transpiration mechanisms and K regulations in two olive genotypes showing different sensitivity to drought stress. In 2017, one-year-old potted ‘Nocellara del Belice’ (NB) and ‘Cerasuola’ (CE) plants were set in a greenhouse and double-bagged to avoid evaporation from soil surface. Half of the plants were drought-stressed (DS, no irrigation) for more than 30 days and the remaining plants were well-watered (WW). At the end of the drought period, stem and root porti…
Resistance simulations for junctions of SW and MW carbon nanotubes with various metal substrates
2011
Abstract This theoretical study focuses on junctions between the carbon nanotubes (CNTs) and contacting metallic elements of a nanocircuit. Numerical simulations on the conductance and resistance of these contacts have been performed using the multiple scattering theory and the effective media cluster approach. Two models for CNT-metal contacts have been considered in this paper: a) first principles “liquid metal” model and b) semi-empirical model of “effective bonds” based on Landauer notions on ballistic conductivity. Within the latter, which is a more adequate description of chirality effects, we have simulated both single-wall (SW) and multi-wall (MW) CNTs with different morphology. Res…
Management of dental anxiety via distraction technique
2021
Background The purpose of this study was to evaluate the use of a stress ball as a distraction technique on stress levels of patients undergoing a dental procedure. Material and methods A randomized, split-mouth design was conducted using 20 adult subjects requiring scaling and root planing (Sc/RP) in all four quadrants. Each side of the mouth (maxillary/mandibular) received Sc/RP with local anesthetic with or without the use of a stress-ball distraction over two separate sessions. Subjects completed two pre-procedural questionnaires (Spielberger State-Trait Anxiety Inventory, STAI; Modified Dental Anxiety Scale, MDAS) before and after each treatment session. A Galvanic Skin Response (GSR) …
a1D-Adrenoceptors are responsible for the high sensitivity and the slow time-course of noradrenaline-mediated contraction in conductance arteries.
2013
The objective of this study was to determine whether the different time-course characteristics of α1-adrenoceptor-mediated contraction in arteries can be related to the subtypes involved. Contractile responses to noradrenaline (NA) were compared with inositol phosphate accumulation and extracellular signal-regulated kinase (ERK)1/2 phosphorylation after α1-agonist stimuli in the same vessels in the presence or absence of α1-antagonists in rat or in α1-subtype knockout (KO) mice. Aorta, where α1D-AR is the main functional subtype, had higher sensitivity to NA (in respect of inositol phosphate [IP], pERK1/2, and contractile response) than tail artery, where the α1A-adrenoceptor subtype is pre…
Changes in the proton-motive force in Escherichia coli in response to external oxidoreduction potential.
1999
International audience; The pH homeostasis and proton-motive force (Deltap) of Escherichia coli are dependent on the surrounding oxidoreduction potential (ORP). Only the internal pH value and, thus, the membrane pH gradient (DeltapH) component of the Deltap is modified, while the membrane potential (DeltaPsi) does not change in a significant way. Under reducing conditions (Eh < 50 mV at pH 7.0), E. coli decreases its Deltap especially in acidic media (21% decrease at pH 7.0 and 48% at pH 5.0 for a 850-mV ORP decrease). Measurements of ATPase activity and membrane proton conductance (CH+m) depending on ORP and pH have shown that the internal pH decrease is due to an increase in membrane prot…
La evaluación del perfeccionismo: utilidad de la Escala Multidimensional de Perfeccionismo en población española
2009
La Escala Multidimensional de Perfeccionismo (MPS) de Frost et al. (1990) es uno de los instrumentos con más tradición empírica y mayor influencia en el estudio del perfeccionismo. El objetivo de este trabajo es traducir y validar la MPS para su uso en población española. Para ello, 434 participantes (77% mujeres; edad media: 23,38 años), completaron la versión española de la MPS junto con cuestionarios de obsesividad, trastornos alimentarios, y preocupaciones ansiosas, para evaluar la validez convergente de la MPS. El análisis de componentes principales (varianza explicada: 56%), reveló una estructura de 4 factores en lugar de los 6 originales: Miedo a los errores, Influencias paternas, Ex…