Anomalous coupling between topological defects and curvature

We investigate a counterintuitive geometric interaction between defects and curvature in thin layers of superfluids, superconductors and liquid crystals deposited on curved surfaces. Each defect feels a geometric potential whose functional form is determined only by the shape of the surface, but whose sign and strength depend on the transformation properties of the order parameter. For superfluids and superconductors, the strength of this interaction is proportional to the square of the charge and causes all defects to be repelled (attracted) by regions of positive (negative) Gaussian curvature. For liquid crystals in the one elastic constant approximation, charges between 0 and $4\pi$ are attracted by regions of positive curvature while all other charges are repelled.Comment: 5 pages, 4 figures, minor changes, accepted for publication in Phys. Rev. Let

T-Dualities and Courant Algebroid Relations

We develop a new approach to T-duality based on Courant algebroid relations which subsumes the usual T-duality as well as its various generalisations. Starting from a relational description for the reduction of exact Courant algebroids over foliated manifolds, we introduce a weakened notion of generalised isometries that captures the generalised geometry counterpart of Riemannian submersions when applied to transverse generalised metrics. This is used to construct T-dual backgrounds as generalised metrics on reduced Courant algebroids which are related by a generalised isometry. We prove an existence and uniqueness result for generalised isometric exact Courant algebroids coming from reductions. We demonstrate that our construction reproduces standard T-duality relations based on correspondence spaces. We also describe how it applies to generalised T-duality transformations of almost para-Hermitian manifolds.Comment: 68 page

Forcing scale invariance in multipolarization SAR change detection

This paper considers the problem of coherent (in the sense that both amplitudes and relative phases of the polarimetric returns are used to construct the decision statistic) multi-polarization SAR change detec- tion starting from the availability of image pairs exhibiting possible power mismatches/miscalibrations. The principle of invariance is used to characterize the class of scale-invariant decision rules which are insensitive to power mismatches and ensure the Constant False Alarm Rate (CFAR) property. A maximal invariant statistic is derived together with the induced maximal invariant in the parameter space which significantly compress the data/parameters domain. A Generalized Likelihood Ratio Test (GLRT) is synthesized both for the cases of two- and three-polarimetric channels. Interestingly, for the two-channel case, it is based on the comparison of the condition number of a data-dependent matrix with a suitable threshold. Some additional invariant decision rules are also proposed. The performance of the considered scale-invariant structures is compared to those from two non- invariant counterparts using both simulated and real radar data. The results highlight the robustness of the proposed method and the performance tradeoff involve

Influence des fluides sur le comportement différé de la craie

National audienceA preliminary experimental study was performed by means of loading stages oedometric tests to highlight the role played by the fluids in the compaction of chalks. Based on a preceding research, the analysis of the North Sea oil reservoir subsidence, the oedometer adaptation to multiphase chalks (air/water or oil/water) required particular precautions. The procedure was validated successfully by the first results which highlight an effect of the fluid saturating on one-dimensional creep. The fluid according to its wettability decreases the resistance and the viscous behaviour starts earlier. Depending on the relationship between the applied stress and the pre consolidation stress, creep is more important when the sample is saturated due to the decrease of the pre consolidation stress. These aspects of the mechanical behaviour of chalks should then be taken into account in an analysis of the long-term stability of underground quarry.Une étude expérimentale préliminaire a été menée au CERMES au moyen d'essais oedométriques par paliers pour mettre en évidence le rôle joué par les fluides lors de la compaction des craies. Fondée sur une recherche précédente, l'analyse de la subsidence des réservoirs pétroliers en Mer du Nord, l'adaptation de l'essai oedométrique aux craies multiphasiques (air/eau ou huile/eau) a nécessité des précautions particulières. La procédure a été validée avec succès par les premiers résultats qui mettent en évidence un effet du fluide saturant sur le fluage unidimensionnel du matériau. En effet, le fluide selon sa mouillabilité diminue la résistance du matériau et amorce un comportement visqueux précoce. Dépendant du rapport entre la contrainte appliquée et la limite élastique, le fluage est plus important quand l'échantillon est saturé du fait de la diminution de la limite élastique qui en suit. La prise en compte de ces aspects du comportement mécanique des craies s'avère indispensable dans l'analyse de la stabilité à long terme d'anciennes carrières souterraines

Functional hemispherical asymmetry with WISC analyses in children with partial epilepsy and normal IQ

We studied 87 normal IQ children, 26 partial epileptic (epileptic group) and 61 non-epileptic children (control group) with mean age of 9 years in relation to cognitive performance in Wechsler Infant Scale for Children (WISC) battery. The epileptic group showed lower score in IQ performance and in three verbal subtests (Information, Digit span, Arithmetic) and three performance subtests (Block Design, Object Assembly and Coding). Patients with right hemisphere EEG focus showed low score in subtests related to spatial ability and non-verbal attention, whereas patients with left hemisphere EEG focus showed low score only in Digit span subtest (related to immediate memory and verbal attention). The authors suggest that cognitive deficits in partial non-lesional epileptic children is related to the side of EEG interictal abnormalities, even in children with normal IQ.Foram avaliadas 26 crianças, sem deficiência mental, com média de idade de 9±2 anos, com epilepsia parcial sem lesão cerebral evidenciável à TCC e com atividade paroxistica no EEG intercrítico localizada apenas em um hemisfério cerebral. Essas crianças foram submetidas à Escala de Inteligência Wechsler para Crianças (WISC) e à análise dos vários subtestes verbais e execução em relação à localização hemisférica da descarga no EEG. Os dados foram comparados ao desempenho no WISC de um grupo de 61 crianças sem epilepsia na mesma faixa etária (Grupo Controle). As crianças epilépticas apresentaram desempenho inferior no QI execução, em três subtestes verbais (Informação, Dígitos e Aritmética) e em três subtestes execução (Cubos, Armar Objetos e Código). Os pacientes com foco eletrencefalográfico no hemisfério direito apresentaram desempenho inferior ao Grupo Controle nos subtestes relacionados à habilidade espacial e atenção não-verbal (Cubos, Armar Objetos e Código), enquanto as crianças com foco no hemisfério esquerdo apresentaram desempenho inferior apenas no subteste de Dígitos (relacionado à memória imediata e atenção verbal). Os autores sugerem que a localização hemisférica do foco no EEG intercrítico tem relação com o tipo de déficit cognitivo associado à epilepsia parcial não-lesional, mesmo em crianças com QI normal.Escola Paulista de MedicinaUNIFESP, EPMSciEL

Real Estate Investment Choices and Decision Support Systems

The evaluation of real estate assets is currently one of the main focal points addressed by territorial marketing strategies, with the view of developing high-performing or competitive cities. Given the complexity of the driving forces that determine the behavior of actors in a real estate market, it is necessary to identify a priori the factors that determine the competitive capacity of a city, to attract investments. The decision support system allows taking into account the key factors that determine the "attractiveness" of real estate investments in competitive urban contexts. This study proposes an integrated complex evaluation model that is able to map out and encapsulate the multidimensional spectrum of factors that shape the attractiveness of alternative real estate options. The conceptual–methodological approach is illustrated by an application of the model to a real-world case study of investment choice in the residential sector of Naples

Pharmacological targets in the ubiquitin system offer new ways of treating cancer, neurodegenerative disorders and infectious diseases

Recent advances in the development and discovery of pharmacological interventions within the ubiquitin–proteasome system (UPS) have uncovered an enormous potential for possible novel treatments of neurodegenerative disease, cancer, immunological disorder and microbial infection. Interference with proteasome activity, although initially considered unlikely to be exploitable clinically, has already proved to be very effective against haematological malignancies, and more specific derivatives that target subsets of proteasomes are emerging. Recent small-molecule screens have revealed inhibitors against ubiquitin-conjugating and -deconjugating enzymes, many of which have been evaluated for their potential use as therapeutics, either as single agents or in synergy with other drugs. Here, we discuss recent advances in the characterisation of novel UPS modulators (in particular, inhibitors of ubiquitin-conjugating and -deconjugating enzymes) and how they pave the way towards new therapeutic approaches for the treatment of proteotoxic disease, cancer and microbial infection

Orexin in the chicken hypothalamus: immunocytochemical localisation and comparison of mRNA concentrations during the day and night, and after chronic food restriction

In mammals Orexin-A and -B are neuropeptides involved in the hypothalamic regulation of diverse physiological functions including food intake and the sleep-wake cycle. This generalisation was investigated in meat-(broiler) and layer-type juvenile domestic chickens by immunocytochemical localisation of orexin A/B in the hypothalamus, and by measurements of hypothalamic hypocretin mRNA which encodes for orexin A/B after chronic food restriction, and during the sleep-wake cycle. Orexin immunoreactive fibres were observed throughout the hypothalamus with cell bodies in and around the paraventricular nucleus. No differences were observed in the pattern of immunoreactivity using anti- human orexin-A, or -B antisera. The amount of hypothalamic hypocretin mRNA in food -restricted broilers was higher than in broilers fed ad libitum, but the same as in layer- type hens fed ad libitum. Hypothalamic hypocretin mRNA was increased (Po0.01) in 12-week-old broilers fed 25% of their ad libitum intake between 6–12 weeks of age. No difference in hypothalamic hypocretin mRNA was seen in 12-week-old layer- type hens when they were awake (1–2 h after lights on) or sleeping (1–2 h after lights off). It is concluded that in the chicken, we could not find evidence that hypothalamic orexin plays a role in the sleep-wake cycle and it may be involved in aspects of energy balance

Lighting up stars in chemical evolution models : the CMD of Sculptor

This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society. ©: 2016 The Author(s). Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.We present a novel approach to draw the synthetic colour–magnitude diagram (CMD) of galaxies, which can provide – in principle – a deeper insight in the interpretation and understanding of current observations. In particular, we ‘light up’ the stars of chemical evolution models, according to their initial mass, metallicity and age, to eventually understand how the assumed underlying galaxy formation and evolution scenario affects the final configuration of the synthetic CMD. In this way, we obtain a new set of observational constraints for chemical evolution models beyond the usual photospheric chemical abundances. The strength of our method resides in the very fine grid of metallicities and ages of the assumed data base of stellar isochrones. In this work, we apply our photochemical model to reproduce the observed CMD of the Sculptor dSph and find that we can reproduce the main features of the observed CMD. The main discrepancies are found at fainter magnitudes in the main sequence turn-off and sub-giant branch, where the observed CMD extends towards bluer colours than the synthetic one; we suggest that this is a signature of metal-poor stellar populations in the data, which cannot be captured by our assumed one-zone chemical evolution model.Peer reviewedFinal Published versio