Search results for "BOLD"
showing 10 items of 52 documents
Natural selection constrains personality and brain gene expression differences in Atlantic salmon (Salmo salar).
2015
ABSTRACT In stream-spawning salmonid fishes there is a considerable variation in the timing of when fry leave the spawning nests and establish a feeding territory. The timing of emergence from spawning nests appears to be related to behavioural and physiological traits, e.g. early emerging fish are bolder and more aggressive. In the present study, emerging Atlantic salmon (Salmo salar L.) alevins were sorted into three fractions: early, intermediate and late emerging. At the parr stage, behaviour, stress responses, hindbrain monoaminergic activity and forebrain gene expression were explored in fish from the early and late emerging fractions (first and last 25%). The results show that when s…
Resting state FMRI: A tool to investigate functional connectivity modulation induced by transcranial direct current stimulation of the motor network
2016
Introduction: Resting-state functional connectivity (fcMRI) represents a novel fMRI approach that allows detection of temporal correlations in spontaneous BOLD signal oscillations while subjects rest quietly in the scanner. Under resting conditions the brain is engaged in spontaneous activity that causes a low frequencies (<0.1 Hz) BOLD signal fluctuations. Functional connectivity (FC) can be defined as the synchrony of neural activity among spatially distant regions. Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that is known to modulate cortical activity and FC among brain regions, as measured by functional magnetic resonance imaging. This st…
Risk aversion connectedness in five European countries
2018
Abstract In this paper we compute an aggregate index of risk aversion and indices of vulnerability and the contribution to systemic risk aversion for five European countries. The variance risk premium proxies risk aversion. The contribution to the literature is twofold. First, this is the first study estimating not only the common component, but also indices of directional connectedness among variance risk premia. Second, it is the first to estimate the interconnections by means of a FIVAR model, in order to account for long memory. Our analysis indicates measures of total and directional connectedness unlike those that would be obtained with the use of a short memory VAR. These differences…
Shaping the antipredator strategy: flexibility, consistency, and behavioral correlations under varying predation threat
2014
9 pages; International audience; Recent ecological and evolutionary research emphasizes the importance of adaptive trait integration. For instance, antipredator defenses are built up of several morphological and behavioral components in many species, yet their functional relationships are still poorly documented. Using field-collected freshwater crustaceans Gammarus fossarum in a within-subject design, we investigated the flexibility and consistency of refuge use, photophobia, and exploration behavior as well as their associations, quantified both when predation risk was absent or artificially simulated. In agreement with the "threat-sensitivity" hypothesis, both refuge use and photophobia …
Caracterización de la actividad biológica y farmacológica del alcaloide boldina en la distrofia miotónica de tipo I
2016
La Distrofia Miotónica de tipo 1 (DM1), es una enfermedad rara sin un tratamiento efectivo. Los tratamientos disponibles en la actualidad se limitan a fármacos paliativos que alivian parcialmente los diferentes síntomas, sin parar o frenar la progresión de la enfermedad. Durante la última década, los avances en la comprensión de las alteraciones que suceden a nivel celular al inicio de la enfermedad han permitido abordar nuevas estrategias en la búsqueda de fármacos, tomándose como diana a los diferentes factores identificados e implicados en el mecanismo de patogénesis de la DM1. En este sentido, en Valentia Biopharma llevamos a cabo un rastreo in vivo de más de 15.000 moléculas químicas d…
Coloration reflects behavioural types in the convict cichlid, Amatitlania siquia.
2015
9 pages; International audience; Interindividual behavioural differences, consistent over time and across situations, are frequently related to differences in reproductive success, susceptibility to disease and competitive ability. The behavioural phenotype of a conspecific is likely to affect the outcome of a social interaction, so an individual must be able to accurately assess behavioural phenotypes in order to optimize behavioural responses during mate choice, cooperative relationships and agonistic interactions. However, behavioural assessment based on dyadic interactions in different contexts can be costly because it may require significant time, increase the risk of predation and oft…
Viatgers romàntics. Els viatges d’Alexander von Humboldt i de Charles Darwin
2013
Tot i pertànyer a generacions diferents i representar formes diferents d’aproximació a l’estudi de la natura, Humboldt i Darwin comparteixen el fet de tenir en l’aventura individual d’un gran viatge iniciàtic la fita determinant de la seva fructífera carrera científica.
Kielentutkimuksen klassikoita
2002
Different mechanism of relaxation induced by aporphine alkaloids in rat uterus.
1993
Abstract We have examined the uterine relaxant action of three aporphine molecules (S-glaucine, S-boldine and R-apomorphine) in two experimental conditions, with and without calcium in the bathing solution, and compared these effects with those obtained with the calcium antagonists verapamil and diltiazem. The present study shows that the alkaloids relax the uterine muscle but with different mechanisms of action. In Ca2+-containing solution all three alkaloids relaxed the uterus previously contracted by KCl or acetylcholine, but in Ca2+-free medium only R-apomorphine was able to relax oxytocin-induced contraction. The calcium antagonists, verapamil and diltiazem, relaxed KCl- or acetylcholi…