GHZ extraction yield for multipartite stabilizer states

Let $|\Psi>$ be an arbitrary stabilizer state distributed between three remote parties, such that each party holds several qubits. Let $S$ be a stabilizer group of $|\Psi>$. We show that $|\Psi>$ can be converted by local unitaries into a collection of singlets, GHZ states, and local one-qubit states. The numbers of singlets and GHZs are determined by dimensions of certain subgroups of $S$. For an arbitrary number of parties $m$ we find a formula for the maximal number of $m$-partite GHZ states that can be extracted from $|\Psi>$ by local unitaries. A connection with earlier introduced measures of multipartite correlations is made. An example of an undecomposable four-party stabilizer state with more than one qubit per party is given. These results are derived from a general theoretical framework that allows one to study interconversion of multipartite stabilizer states by local Clifford group operators. As a simple application, we study three-party entanglement in two-dimensional lattice models that can be exactly solved by the stabilizer formalism.Comment: 12 pages, 1 figur

Les lésions médullaires traumatiques : épidémiologie et perspectives

AbstractObjectiveSpecify the epidemiological data on the acute spinal cord injuries and define a group of patients that could benefit from cellular transplantation therapy designed with the aim of repair and regeneration of damaged spinal cord tissues.Material and methodsFive years monocentric (Gui-de-Chauliac Hospital, Montpellier, France) retrospective analysis of patients suffering from spinal cord injury (SCI). Spinal cord injured-patients, defined as sensory-motor complete, underwent a clinical evaluation following American Spinal Injury Association (ASIA) and functional type 2 Spinal Cord Independence Measure (SCIM2) scorings as well as radiological evaluation through spinal cord magnetic resonance imaging (MRI).ResultsOne hundred and fifty-seven medical records were reviewed and we selected and re-examined 20 patients with complete thoracic spinal cord lesion. Clinical and radiological evaluations of these patients demonstrated, in 75 % of the cases, an absence of clinical progression after a mean of 49months. Radiological abnormalities were constantly present in the initial (at the admission to hospital) and control (re-evaluation) MRI and no reliable predictive criteria of prognosis had been found.Discussion/ConclusionWe compare our results to the literature and discuss advantages and limits of cellular transplantation strategies for these patients.RésuméObjectifsConnaître les données épidémiologiques de notre région sanitaire sur les traumatismes médullaires. Au sein de cette population, sélectionner les patients susceptibles de bénéficier de thérapie cellulaire dans la moelle épinière lésée dans l’objectif de régénérer le tissu nerveux. Évaluer à distance ces patients.Patients et méthodeAnalyse rétrospective de tous les patients pris en charge pour un traumatisme vertébro-médullaire. Réévaluation clinique et radiologique des patients présentant une atteinte médullaire thoracique sensitivomotrice complète. Réévaluation réalisée par le score de l’American Spinal Injury Association (ASIA), le score fonctionnel Type 2 Spinal Cord Independence Measure (SCIM2) et contrôle radiologique par une IRM médullaire.RésultatsCent cinquante-sept dossiers de patients ont été analysés et 28 patients présentaient une lésion médullaire complète. Une évaluation clinique et radiologique réalisée chez 20 patients sur 28 (71 %) a montré l’absence d’évolution clinique dans 75 % des cas dans un délai moyen de 49 mois. Les anomalies radiologiques étaient présentes dans 100 % des cas sur l’IRM initiale et de contrôle sans qu’aucun critère fiable prédictif de bon pronostic n’est retrouvé.Discussion/conclusionNous présentons ces résultats comparativement à ceux de la littérature et nous discutons chez ces malades les stratégies de transplantation cellulaire, leurs limites actuelles et les progrès nécessaires pour obtenir des résultats

Protection against Clostridium difficile infection in a hamster model by oral vaccination using flagellin FliC-loaded pectin beads

International audienceClostridium difficile flagellin FliC is a highly immunogenic pathogen-associated molecular pattern playing a key role in C. difficile pathogenesis and gut colonization. Here, we designed an oral vaccine against C. difficile with FliC encapsulated into pectin beads for colonic release. Bead stability and FliC retention was confirmed in vitro using simulated intestinal media (SIM), while bead degradation and FliC release was observed upon incubation in simulated colonic media (SCM). The importance of FliC encapsulation into pectin beads for protection against C. difficile was assessed in a vaccination assay using a lethal ham-ster model of C. difficile infection. Three groups of hamsters orally received either FliC-loaded beads or unloaded beads in gastro-resistant capsule to limit gastric degradation or free FliC. Two other groups were immunized with free FliC, one intra-rectally and the other intra-peritoneally. Hamsters were then challenged with a lethal dose of C. difficile VPI 10463. Fifty percent of hamsters orally immunized with FliC-loaded beads survived whereas all hamsters orally immunized with free FliC died within 7 days post challenge. No significant protection was observed in the other groups. Only intra-peritoneally immunized hamsters presented anti-FliC IgG antibodies in sera after immunizations. These results suggest that an oral immunization with FliC-loaded beads probably induced a mucosal immune response, therefore providing a protective effect. This study confirms the importance of FliC encapsulation into pectin beads for a protective oral vaccine against C. difficile

Photoluminescence of single colour defects in 50 nm diamond nanocrystals

We used optical confocal microscopy to study optical properties of diamond 50 nm nanocrystals first irradiated with an electron beam, then dispersed as a colloidal solution and finally deposited on a silica slide. At room temperature, under CW laser excitation at a wavelength of 514.5 nm we observed perfectly photostable single Nitrogen-Vacancy (NV) colour defects embedded in the nanocrystals. From the zero-phonon line around 575 nm in the spectrum of emitted light, we infer a neutral NV0 type of defect. Such nanoparticle with intrinsic fluorescence are highly promising for applications in biology where long-term emitting fluorescent bio-compatible nanoprobes are still missing.Comment: proceedings of ICDS 23 conference (23rd International Conference on Defects in Semiconductors, July 24 - July 29, 2005, Awaji Island, Hyogo, Japan); to appear in "Physica B

A imigração e a língua de acolhimento em Portugal: questões de identidade e integração

A imigração, a diversidade e a multiculturalidade estão cada vez mais presentes nas sociedades modernas e a gestão desta realidade representa um enorme desafio, tanto para as sociedades de acolhimento como para os próprios imigrantes. Esse desafio implica um processo de adaptação e integração que apenas pode funcionar havendo vontade e esforço de ambas as partes envolvidas. O país (sociedade) de acolhimento deve trabalhar no sentido de promover um ambiente onde nativos e imigrantes possam conviver pacificamente garantindo a todos o respeito por direitos e deveres, bem como pelas suas identidades. Quanto aos imigrantes, têm que se adaptar a uma nova vida e uma nova realidade longe dos seus países de origem, devendo também eles respeitar o meio em que se encontram e do qual passam a fazer parte, ao mesmo tempo que tentam preservar as suas identidades e os laços com o seu país de origem. É um processo que envolve muitas mudanças, particularmente para os imigrantes. O país, a sociedade, os costumes, a cultura, o clima, as crenças, a língua, etc, fazem parte de um conjunto de novas experiências e novas aprendizagens para o imigrante. Essas novas experiências trazidas pela imigração têm a potencialidade de gerar mudança identitária. Através de um estudo que pretendeu dar voz aos próprios imigrantes, procurei neste trabalho perceber se há realmente mudanças ao nível da identidade provocadas pelo processo de imigração e de que modo atuam alguns elementos nessa mudança e no processo de integração, nomeadamente a língua – língua materna e língua de acolhimento.Abstract: Immigration, diversity and multiculturalism are every day more present in the modern society and dealing with this reality represents a big challenge for both, host society and the immigrants. It requires a process of adaptation and integration that can only work if both parts are involved and willing to make things work. The host society must promote an environment where natives and immigrants can live together peacefully and also guarantee that all legal rights and obligations are respected as well as people’s identities. When it comes to the immigrants, they have to adapt to a new culture and environment, making sure they respect the society which they are now part of, and also try to preserve their identities and the bound with their own country and people. It's a process that involves many changes, more so to the immigrants. The nation, society, habits, culture, weather, beliefs, language, etc., are all new experiences to them. These integration and experiences could have the potential to generate identity changes. Through a study that wanted to listen to the immigrants opinions and experiences, I’ve tried to understand if there are actually changes in immigrants identities as a result of the migration process and how do some elements take place in that change, particularly the language - language from the host society and language from the origin country

Severe Mg-deficiency is not associated with endothelial cell activation in mouse lung

Abstract. Several experimental and clinical studies suggest that the lungs are a specific target of Mg-hypomagnesemia, which is a common side effect of cyclosporin A therapy. Due to the possible effect of hypomagnesemia on lung allograft function, the aim of this study was to evaluate endothelial cell (EC) activation and tissue remodelling (apoptosis) in the lungs from mice fed Mg-deficient diets. Immunocytochemical examinations did not reveal any inflammatory process in Mg-deficient mice, infiltration of leukocytes (CD45 + cells), expression of I-A b class II molecules, E-selectin or ICAM-1 on ECs, and apoptotic cells. Quantification of mRNAs for E-selectin, ICAM-1 and VCAM-1, which are the most pertinent adhesins expressed by ECs, and for the cytokines TNFa and IL-2, demonstrated that severe Mg-deficiency does not result in EC activation. The balance between the up-regulation of G-CSF-R and CCL4 genes, and the down-regulation of the OPN gene shown by the cDNA microarray technique might be responsible for the absence of development of an inflammatory response, lung EC activation, and lung remodelling. However, we can hypothesize that severe Mg deficiency results in a latent inflammatory status of the lungs, which might be expressed following immune stresses, like transplantation conditions

Aberration-free ultra-thin flat lenses and axicons at telecom wavelengths based on plasmonic metasurfaces

The concept of optical phase discontinuities is applied to the design and demonstration of aberration-free planar lenses and axicons, comprising a phased array of ultrathin subwavelength spaced optical antennas. The lenses and axicons consist of radial distributions of V-shaped nanoantennas that generate respectively spherical wavefronts and non-diffracting Bessel beams at telecom wavelengths. Simulations are also presented to show that our aberration-free designs are applicable to high numerical aperture lenses such as flat microscope objectives

Quality and Safety Aspects of Infant Nutrition

Quality and safety aspects of infant nutrition are of key importance for child health, but oftentimes they do not get much attention by health care professionals whose interest tends to focus on functional benefits of early nutrition. Unbalanced diets and harmful food components induce particularly high risks for untoward effects in infants because of their rapid growth, high nutrient needs, and their typical dependence on only one or few foods during the first months of life. The concepts, standards and practices that relate to infant food quality and safety were discussed at a scientific workshop organized by the Child Health Foundation and the Early Nutrition Academy jointly with the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, and a summary is provided here. The participants reviewed past and current issues on quality and safety, the role of different stakeholders, and recommendations to avert future issues. It was concluded that a high level of quality and safety is currently achieved, but this is no reason for complacency. The food industry carries the primary responsibility for the safety and suitability of their products, including the quality of composition, raw materials and production processes. Introduction of new or modified products should be preceded by a thorough science based review of suitability and safety by an independent authority. Food safety events should be managed on an international basis. Global collaboration of food producers, food-safety authorities, paediatricians and scientists is needed to efficiently exchange information and to best protect public health. Copyright (C) 2012 S. Karger AG, Base

A framework for digital sunken relief generation based on 3D geometric models

Sunken relief is a special art form of sculpture whereby the depicted shapes are sunk into a given surface. This is traditionally created by laboriously carving materials such as stone. Sunken reliefs often utilize the engraved lines or strokes to strengthen the impressions of a 3D presence and to highlight the features which otherwise are unrevealed. In other types of reliefs, smooth surfaces and their shadows convey such information in a coherent manner. Existing methods for relief generation are focused on forming a smooth surface with a shallow depth which provides the presence of 3D figures. Such methods unfortunately do not help the art form of sunken reliefs as they omit the presence of feature lines. We propose a framework to produce sunken reliefs from a known 3D geometry, which transforms the 3D objects into three layers of input to incorporate the contour lines seamlessly with the smooth surfaces. The three input layers take the advantages of the geometric information and the visual cues to assist the relief generation. This framework alters existing techniques in line drawings and relief generation, and then combines them organically for this particular purpose