Search results for "Ley"
showing 10 items of 1218 documents
Coarse-Grained Barrier Trees of Fitness Landscapes
2016
Recent literature suggests that local optima in fitness landscapes are clustered, which offers an explanation of why perturbation-based metaheuristics often fail to find the global optimum: they become trapped in a sub-optimal cluster. We introduce a method to extract and visualize the global organization of these clusters in form of a barrier tree. Barrier trees have been used to visualize the barriers between local optima basins in fitness landscapes. Our method computes a more coarsely grained tree to reveal the barriers between clusters of local optima. The core element is a new variant of the flooding algorithm, applicable to local optima networks, a compressed representation of fitnes…
: Metonymy, Identification and Subjecthood in Stanley Kubrick's Lolita (1962)
2009
The author argues that, in order to bypass the Hays code, the eroticism in Kubrick's film is produced by metonymy, both verbal and non-verbal. Basing his study on the works of Christian Metz and Laura Mulvey, and more broadly on Lacanian psychoanalysis, the author analyzes how the film first constructs the character of Lolita as a “sexual object” subjected to the male gaze, then deconstructs its own construction by enabling Lolita to accede to the symbolic order, thus breaking out of the solipsistic imaginary the pedophile had confined her to. The film puts the spectator in the pervert's shoes by encouraging primary identification with the camera eye, secondary identification with Humbert H…
On the variations of the Betti numbers of regular levels of Morse flows
2011
Abstract We generalize results in Cruz and de Rezende (1999) [7] by completely describing how the Betti numbers of the boundary of an orientable manifold vary after attaching a handle, when the homology coefficients are in Z, Q, R or Z p Z with p prime. First we apply this result to the Conley index theory of Lyapunov graphs. Next we consider the Ogasa invariant associated with handle decompositions of manifolds. We make use of the above results in order to obtain upper bounds for the Ogasa invariant of product manifolds.
Lyapunov graphs for circle valued functions
2018
International audience; Conley index theory is used to obtain results for flows associated to circular Lyapunov functions defined on general compact smooth n-manifolds. This is done in terms of their underlying circular Lyapunov digraphs, which are generalizations of Morse digraphs, by extensively studying their combinatorics, invariants and realizability.
Effect of oxidative stress on UDP-glucuronosyltransferases in rat astrocytes.
2012
WOS:000309170300003; International audience; The present work reports data regarding effects of an induced oxidative stress on the mainly expressed isoforms of UDP-glucuronosyltransferases (UGTs) in the brain. UGT1A6 and UGT1A7 expression and enzymatic activities toward the 1-naphthol were analyzed in rat cultured astrocytes following the exposure for 48 h to redox-cycling xenobiotic compounds such as quinones and bipyridinium ions. The expression of NADPH:cytochrome P450 reductase and NAD(P)H:quinone oxidoreductase 1 (NQO1) was also investigated. Oxidative stress induced significant deleterious changes in astrocyte morphology, decreased cell viability and inhibited catalytic function of UG…
Synthesis and in vitro studies on a potential dopamine prodrug.
2008
Dopamine delivery to the central nervous system (CNS) undergoes the permeability limitations of blood-brain barrier (BBB) which is a selective interface that excludes most water-soluble molecules from entering the brain. Neutral amino acids permeate the BBB by specific transport systems. Conden- sation of dopamine with neutral amino acids could afford potential prodrugs able to interact with the BBB endogenous transporters and easily enter the brain. The synthesis and characterization of the dopamine derivative 2-amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (7) is de- scribed. The chemical and enzymatic stability of 7 was evaluated. The molecular weight (300 Da) and Log P …
Generalization of seizures parallels the formation of "dark" neurons in the hippocampus and pontine reticular formation after focal-cortical applicat…
2008
Abstract Distribution and time course of the occurrence of “dark” neurons were compared with the EEG activity and behavior of rats during 4-aminopyridine (4-AP) induced epileptic seizures. A crystal of the K + channel blocker 4-AP (0.5 mg/kg) was placed onto the exposed parieto-occipital cortex of Halothane-anesthetized rats for 40 min. Thereafter, the anesthesia was discontinued and the behavioral signs of the epileptic seizure activity were observed. The presence of “dark” neurons was demonstrated by the sensitive silver method of Gallyas in rats sacrificed at 0, 3 and 6 h after the end of the 4-AP crystal application. The EEG activity was recorded in the rats with longer survival times. …
Effects of tetrahydrocannabinol on glucose uptake in the rat brain
2017
Δ9-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain. The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain. 21 male Sprague Dawley rats (12-13 w) were examined and received five different doses of THC ranging from 0.01 to 1 mg/kg. For data acquisition a Focus 120 small animal PET scanner was used and 24.1-28.0 MBq of [18F]-fluoro-2-deoxy-d-glucose were injected. The data were acquired for 70 min and arterial blood samples were collected throughout the scan. THC, THC-OH and THC-COOH were determined at 55 min p.i. Nine volu…
Telmisartan cardioprotects from the ischaemic/hypoxic damage through a miR‐1‐dependent pathway
2019
The aim of this study was to investigate whether telmisartan protects the heart from the ischaemia/reperfusion damage through a local microRNA-1 modulation. Studies on the myocardial ischaemia/reperfusion injury in vivo and on the cardiomyocyte hypoxia/reoxygenation damage in vitro were done. In vivo, male Sprague-Dawley rats administered for 3 weeks with telmisartan 12 mg/kg/d by gastric gavage underwent ischaemia/reperfusion of the left descending coronary artery. In these rats, infarct size measurement, ELISA, immunohistochemistry (IHC) and reverse transcriptase real-time polymerase chain reaction showed that expressions of connexin 43, potassium voltage-gated channel subfamily Q member …
Early life stress is a risk factor for excessive alcohol drinking and impulsivity in adults and is mediated via a CRF/GABAA mechanism
2016
Childhood stress and trauma are associated with substance use disorders in adulthood, but the neurological changes that confer increased vulnerability are largely unknown. In this study, maternal separation (MS) stress, restricted to the pre-weaning period, was used as a model to study mechanisms of protracted effects of childhood stress/traumatic experiences on binge drinking and impulsivity. Using an operant self-administration model of binge drinking and a delay discounting assay to measure impulsive-like behavior, we report that early life stress due to MS facilitated acquisition of binge drinking and impulsivity during adulthood in rats. Previous studies have shown heightened levels of…