Search results for " Plastic"
showing 10 items of 3463 documents
Quando la malattia “rimette in forma”: la plasticità distruttrice e le figure del trauma
2019
Nowadays, philosophy must confront the emergence of new concepts of illness and “the new wounded”. Meaning with this term individuals who suffer from pathologies affecting their identity and upsetting their affective economy. In her works, Catherine Malabou, one of the most influential thinkers in the contemporary French debate, investigates the affective isolation of Alzheimer’s patients, the loneliness of those who suffer with depression, and the pain experienced by the “survivors” of identity destruction; she does so in constant dialogue with the European philosophical tradition (Spinoza in particular) and recent discoveries in neuroscience. These themes also imply the use of a new conce…
Ontologia dell’accidente. Saggio sulla plasticità distruttrice
2019
In conseguenza di gravi traumi, talvolta per un nonnulla, la storia di ognuno di noi può subire un radicale cambiamento: la vita che avevamo progettato per anni è costretta a una deviazione improvvisa e irreversibile. Dal trauma sorge una personalità nuova, senza precedenti. Una personalità nata da un incidente, nata per accidente. Il fortuito diviene così sostanziale e l’inaspettato s’inscrive nel nucleo più profondo del nostro essere. Affrontando con delicatezza il tema dell’impatto che i traumi psicofisici possono avere sulla nostra vita, Catherine Malabou intraprende un’avventura filosofica e letteraria in cui Spinoza, Deleuze e Freud incrociano Ovidio, Kafka, Proust e Duras, disegnando…
Carry-over effects of conditions at the wintering grounds on breeding plumage signals in a migratory bird : roles of phenotypic plasticity and select…
2016
To understand the consequences of ever-changing environment on the dynamics of phenotypic traits, distinguishing between selection processes and individual plasticity is crucial. We examined individual consistency/plasticity in several male secondary sexual traits expressed during the breeding season (white wing and forehead patch size, UV reflectance of white wing patch and dorsal melanin coloration) in a migratory pied flycatcher (Ficedula hypoleuca) population over an 11-year period. Furthermore, we studied carry-over effects of three environmental variables (NAO, a climatic index; NDVI, a vegetation index; and rainfall) at the wintering grounds (during prebreeding moult) on the expressi…
Sexual selection, phenotypic plasticity and female reproductive output
2019
In a rapidly changing environment, does sexual selection on males elevate a population's reproductive output? If so, does phenotypic plasticity enhance or diminish any such effect? We outline two routes by which sexual selection can influence the reproductive output of a population: a genetic correlation between male sexual competitiveness and female lifetime reproductive success; and direct effects of males on females' breeding success. We then discuss how phenotypic plasticity of sexually selected male traits and/or female responses (e.g. plasticity in mate choice), as the environment changes, might influence how sexual selection affects a population's reproductive output. Two key points…
Natural selection mediated by seasonal time constraints increases the alignment between evolvability and developmental plasticity
2021
Abstract Phenotypic plasticity can either hinder or promote adaptation to novel environments. Recent studies that have quantified alignments between plasticity, genetic variation, and divergence propose that such alignments may reflect constraints that bias future evolutionary trajectories. Here, we emphasize that such alignments may themselves be a result of natural selection and do not necessarily indicate constraints on adaptation. We estimated developmental plasticity and broad sense genetic covariance matrices (G) among damselfly populations situated along a latitudinal gradient in Europe. Damselflies were reared at photoperiod treatments that simulated the seasonal time constraints ex…
SIGNAL RELIABILITY COMPROMISED BY GENOTYPE-BY-ENVIRONMENT INTERACTION AND POTENTIAL MECHANISMS FOR ITS PRESERVATION
2007
Sexual selection based on signaling requires that signals used by females in mate choice are reliable indicators of a male's heritable total fitness. A signal and the preference for it are expected to be heritable, resulting in the maintenance of genetic covariance between these two traits. However, a recent article has proposed that signals may quickly become unreliable in the presence of both environmental variation and genotype-by-environment interaction (G x E) with crossing reaction norms, potentially compromising the mechanisms of sexual selection. Here we examine the heritability and plasticity of a male dominance advertisement in the bank vole, Clethrionomys glareolus, in stable and…
Sex Differences in the Neuroadaptations of Reward-related Circuits in Response to Subchronic Variable Stress
2018
Women are twice as likely to be diagnosed with major depressive disorder. However, fewer studies in rodent models of depression have used female animals, leading to a relative lack of understanding of the female brain’s response to stress, especially at a neural circuit level. In this study, we utilized a 6-day subchronic variable stress (SCVS) mouse model and measured novelty suppressed feeding as behavioral criteria to evaluate susceptibility to SCVS in male and female mice. First, we showed that SCVS induced a decrease in latency to eat (susceptible phenotype) in female mice, but not in males (resilient phenotype). After determining behavioral phenotypes, we investigated the firing activ…
Neuroprotective action of diazepam at very low and moderate doses in Alzheimer's disease model rats
2018
Abstract Early manifestations of Alzheimer's disease (AD) include neuroinflammation, disrupted neurotransmission and cognitive deficits. Impairment of the GABAergic system is essentially involved in the pathogenesis of AD. Traditionally, agonists of GABAA receptors at doses above 1 mg/kg are known to possess memory impairing effects. However, we have previously found that GABAA receptor GABA site ligand muscimol at very low doses acted contrary – enhanced spatial learning/memory, as well as prevented neuroinflammation and augmented neurotransmission in AD model rats. Therefore, in the present study we focused on the assessment of the effects of non-sedative – very low (0.05 mg/kg) and moder…
Functional Plasticity after Unilateral Vestibular Midbrain Infarction in Human Positron Emission Tomography.
2016
The aim of the study was to uncover mechanisms of central compensation of vestibular function at brainstem, cerebellar, and cortical levels in patients with acute unilateral midbrain infarctions presenting with an acute vestibular tone imbalance. Eight out of 17 patients with unilateral midbrain infarctions were selected on the basis of signs of a vestibular tone imbalance, e.g., graviceptive (tilts of perceived verticality) and oculomotor dysfunction (skew deviation, ocular torsion) in F18-fluordeoxyglucose (FDG)-PET at two time points: A) in the acute stage, and B) after recovery 6 months later. Lesion-behavior mapping analyses with MRI verified the exact structural lesion sites. Group su…
Absence of germline CDKN2A mutation in Sicilian Patients with Familial Malignant Melanoma: could it be a population-specific genetic signature?
2015
Germline CDKN2A mutations have been described in 25% to 40% of melanoma families from several countries. Sicilian population is genetically different from the people of Europe and Northern Italy because of its historical background, therefore familial melanoma could be due to genes different from high-penetrance CDKN2A gene. Four hundred patients with cutaneous melanoma were observed in a 6-years period at the Plastic Surgery Unit of the University of Palermo. Forty-eight patients have met the criteria of the Italian Society of Human Genetics (SIGU) for the diagnosis of familial melanoma and were screened for CDKN2A and CDK4 mutations. Mutation testing revealed that none of the families car…