We determine 37 differential extinctions in 23 gravitational lens galaxies over the range 0 < ∼ z l < ∼ 1. Only 7 of the 23 systems have spectral differences consistent with no differential extinction. The median differential extinction for the optically-selected (radio-selected) subsample is ∆E(B − V) = 0.04 (0.06) mag. The extinction is patchy and shows no correlation with impact parameter. T...

Although conditioned fear can be effectively extinguished by unreinforced exposure to a threat cue, fear responses tend to return when the cue is encountered some time after extinction (spontaneous recovery), in a novel environment (renewal), or following presentation of an aversive stimulus (reinstatement). As extinction represents a context-dependent form of new learning, one possible strateg...

Many factors account for how well individuals extinguish conditioned fears, such as genetic variability, learning capacity and conditions under which extinction training is administered. We predicted that memory-based interventions would be more effective to reduce the reinstatement of fear in subjects genetically predisposed to display more extinction learning. We tested this hypothesis in rat...

It has been reported that stress-related activation of the noradrenergic system strengthens the formation of aversive memories and that beta-adrenergic receptors seem to be involved in this emotional memory processing. In this study, the effects of beta-adrenergic compounds on the extinction of contextual conditioned fear responses were evaluated. Rats were trained with footshock in a condition...

A reliable personal recognition based on ear biometrics is highly in demand due to its vast application in automated surveillance, law enforcement etc. In this paper a robust ear recognition system is proposed using gradient ordinal relationship pattern. A reference point based normalization is proposed along with a novel ear transformation over normalized ear, to obtain robust ear representati...

It is well known that for an isolated population, the probability of extinction is positively related to population size variation: more variation is associated with more extinction. What, then, is the relation of extinction to population size variation for a population embedded in a metapopulation and subjected to repeated extinction and recolonization? In this case, the extinction risk can be...

Understanding how plant life history affects species vulnerability to anthropogenic disturbances and environmental change is a major ecological challenge. We examined how vegetation type, growth form, and geographic range size relate to extinction risk throughout the Brazilian Atlantic Forest domain. We used a database containing species-level information of 6,929 angiosperms within 112 familie...

Extinction-based exposure therapy is used to treat anxiety- and trauma-related disorders; however, there is the need to improve its limited efficacy in individuals with impaired fear extinction learning and to promote greater protection against return-of-fear phenomena. Here, using 129S1/SvImJ mice, which display impaired fear extinction acquisition and extinction consolidation, we revealed tha...