Constrained MaxLik reconstruction of multimode photon distributions

We address the reconstruction of the full photon distribution of multimode fields generated by seeded parametric down-conversion (PDC). Our scheme is based on on/off avalanche photodetection assisted by maximum-likelihood (MaxLik) estimation and does not involve photon counting. We present a novel constrained MaxLik method that incorporates the request of finite energy to improve the rate of convergence and, in turn, the overall accuracy of the reconstruction

Involvement of long non-coding RNAs in beta cell failure at the onset of type 1 diabetes in NOD mice.

AIMS/HYPOTHESIS: Exposure of pancreatic beta cells to cytokines released by islet-infiltrating immune cells induces alterations in gene expression, leading to impaired insulin secretion and apoptosis in the initial phases of type 1 diabetes. Long non-coding RNAs (lncRNAs) are a new class of transcripts participating in the development of many diseases. As little is known about their role in insulin-secreting cells, this study aimed to evaluate their contribution to beta cell dysfunction. METHODS: The expression of lncRNAs was determined by microarray in the MIN6 beta cell line exposed to proinflammatory cytokines. The changes induced by cytokines were further assessed by real-time PCR in islets of control and NOD mice. The involvement of selected lncRNAs modified by cytokines was assessed after their overexpression in MIN6 cells and primary islet cells. RESULTS: MIN6 cells were found to express a large number of lncRNAs, many of which were modified by cytokine treatment. The changes in the level of selected lncRNAs were confirmed in mouse islets and an increase in these lncRNAs was also seen in prediabetic NOD mice. Overexpression of these lncRNAs in MIN6 and mouse islet cells, either alone or in combination with cytokines, favoured beta cell apoptosis without affecting insulin production or secretion. Furthermore, overexpression of lncRNA-1 promoted nuclear translocation of nuclear factor of κ light polypeptide gene enhancer in B cells 1 (NF-κB). CONCLUSIONS/INTERPRETATION: Our study shows that lncRNAs are modulated during the development of type 1 diabetes in NOD mice, and that their overexpression sensitises beta cells to apoptosis, probably contributing to their failure during the initial phases of the disease

A Comprehensive Framework for the Security Risk Management of Cyber-Physical Systems

Cyber Physical Systems are facing huge and diverse set of security risks, especially cyber-attacks that can cause disruption to physical services or create a national disaster. Information and communication technology (ICT) has made a remarkable impact on the society. A Cyber Physical System (CPS) relies basically on information and communication technology, which puts the system\u2019s assets under certain risks especially cyber ones, and hence they must be kept under control by means of security countermeasures that generate confidence in the use of these assets. And so there is a critical need to give a great attention on the cybersecurity of these systems, which consequently leads to the safety of the physical world. This goal is achieved by adopting a solution that applies processes, plans and actions to prevent or reduce the effects of threats. Traditional IT risk assessment methods can do the job, however, and because of the characteristics of a CPS, it is more efficient to adopt a solution that is wider than a method, and addresses the type, functionalities and complexity of a CPS. This chapter proposes a framework that breaks the restriction to a traditional risk assessment method and encompasses wider set of procedures to achieve a high level strategy that could be adopted in the risk management process, in particular the cybersecurity of cyber-physical systems

Acute toxicity and antioxydant property of Striga hermonthica (Del.) Benth (Scrophulariaceae)

Plants containing flavonoids have been reported to possess strong antioxidant properties. The aqueous acetone extract of Striga hermonthica was further separated into aqueous and ethyl acetate fractions and assayed for their in vitro antioxidant properties using 2,2-diphenyl-1-picrylhydrazyl (DPPH). Thecrude extract exhibits a weak antioxidant activity (IC50 of 95.27±2.30 ìg/ml) and an insignificant acute toxicity on mice (LD50: 1753±44 mg/kg). Luteolin was isolated and identified by mean of its spectral data as the main DPPH radical scavenger of the ethyl acetate fraction, exhibiting an IC50 value of 6.80±1.46 ìg/ml. These results suggest an antioxidant potential for S. hermonthica

La grille au service du développement médical en Afrique

PCSV, présenté par F. Jacq, pas de proceedingsObjectives: Telemedicine networks allow to train local physicians and to improve diagnosis by exchanging medical data. But the set-up of multipoint dynamic telemedicine requires moving towards GRID technologies. The objective is to develop telemedicine services for physicians from Burkina Faso and France with the perspective of setting up a grid infrastructure between the participating medical sites. Methods: A web site to exchange diagnosis on diabetic retinopathy was developed in PHP. Another application using web services was developed to exchange patient information on ophthalmology between two databases. Results: The main difficulty comes from limited resources in developing countries including staff skills, bandwidth and funding. But the collaboration with dispensaries opened a door to enhanced collaboration between physicians of France and Burkina Faso Conclusions: These applications are designed with the aim of their use on grids which opens the perspective of multipoint dynamic telemedicine. We are developing a new generation of telemedicine service using experience acquired in the last two years

Biphoton compression in standard optical fiber: exact numerical calculation

Generation of two-photon wavepackets, produced by spontaneous parametric down conversion in crystals with linearly chirped quasi-phase matching grating, is analyzed. Although being spectrally broad, two-photon wavepackets produced this way are not Fourier transform limited. In the paper we discuss the temporal compression of the wavepackets, exploiting the insertion of a standard optical fiber in the path of one of the two photons. The effect is analyzed by means of full numerical calculation and the exact dispersion dependencies in both the crystal and the fiber are considered. The study opens the way to the practical realization of this idea.Comment: 10 pages, 16 figure

Acceptability of interventions to reduce mother-to-child transmission of HIV-1 in West Africa

Would HIV-1-positive African women use interventions of AIDS testing, medication (oral and vaginal), and vaginal disinfection to reduce the likelihood of HIV-1 transmission to their child ? In this pilot study in two west African cities (Abidjan, Côte d'Ivoire, and Bobo-Dioulasso, Burkina Faso), social workers gave a native-language questionnaire to 607 pregnant women at four Maternal and Child Health Centers. The women were asked about their perception of the HIV test ; consequences of testing and counseling ; choice of medical intervention to protect the future child ; and feelings about being in a randomized, placebo-controlled, clinical trial. Most accepted the principle of an AIDS test, said they wanted the agreement of their regular partner before being tested, and would use interventions to reduce the risk of vertical transmission. The researchers concluded that although concepts of informed consent, randomization, and placebo are difficult to understand, the study results are promising and encourage the evaluation of clinical trials to reduce mother-to-child transmission. (Résumé d'auteur

Measurement of sub-shot-noise spatial correlations without subtraction of background

In this paper we present the first measurement of sub-shot-noise spatial correlations without any subtraction of background, a result opening the way to realize sub-shot-noise imaging of weak objectsComment: 4 pages, 4 figure