46 research outputs found

    A complex sinusoids estimation method based on the deconvolution of the periodogram : "expulse"

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    EXPULSEmethod lifts the main drawback of the classical high resolution spectral analysis methods (MUSIC, MINORM, . . .) which have a poor robustness with respect to an unreliable knowledge of the number of sources . Its novelty stems from the modeling of the periodogram of complex sinusoids embedded in an additive noise, as the convolution of a perfectly known kernel (depending upon the window) and a compound Bernoulli-Gaussian process, plus a noise . The discrete frequencies where the Bernoulli process takes 1 values locate the sinusoids ; the gaussian process describes the amplitudes .La méthode EXPULSE pallie l'une des principales limitations des techniques traditionnelles d'Analyse Spectrale à Haute Résolution ASHR (MUSIC, Norme minimale, etc.) à savoir la faible robustesse vis-à-vis d'une méconnaissance de leur nombre. Son originalité repose sur l'interprétation d'un périodogramme mis en oeuvre sur un processus de raies pures noyées dans un bruit additif, comme la convolution, à un bruit près, d'un processus composite Bernoulli-Gaussien avec une fonction spectrale parfaitement connue qui dépend de la calibration retenue du périodogramme (type de fenêtre d' apodisation, lissage temporel ou fréquentiel, etc.). Les fréquences discrètes où le processus de Bemoulli prend la valeur 1 sont des raies potentielles de l'espace signal ; le processus gaussien caractérise quant à lui l'amplitude des raies

    HIV infection and severe malnutrition: a clinical and epidemiological study in Burkina Faso.

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    OBJECTIVE: To define a clinical profile indicative of HIV infection in a population of severely malnourished children in Burkina Faso. A total of 433 children (average age, 19 months) were recruited at the Sanou Souro National Hospital, Bobo Dioulasso, Burkina Faso. RESULTS: Sixty-three per cent presented with marasmus, 13% with kwashiorkor and 24% with both forms of malnutrition. The prevalence of HIV infection in children aged over 12 months was 13.8%, with a marked predominance of HIV-1 (95.8%). Mother-to-child transmission was proven in 77% of the cases; in 10% of the observed paediatric AIDS cases, transmission may have occurred through multi-injections with contaminated equipment. Marasmus was the form of malnutrition most frequently associated with HIV (P < 0.001); its severity was exacerbated by HIV infection. Adenopathy (P < 0.0001), oral candidiasis (P < 0.0006), skin disorders (P < 0.01) and hepatomegaly (P = 0.01) appeared to be significantly related to HIV infection. Discriminant analysis revealed that the presence of adenopathies was the strongest indicator symptom of HIV infection. Multivariate analysis revealed that a clinical profile of marasmus, adenopathies and oral candidiasis (specificity, 82%) was indicative of HIV infection in this population. The short-term clinical prognosis was poor and usually led to the death of the child when seropositive (P < 0.001). CONCLUSIONS: Among children exhibiting severe malnutrition, HIV-positive children are distinguished by a high horizontal transmission rate, a high specific clinical profile and a very poor prognosis

    Towards third generation matrix metalloproteinase inhibitors for cancer therapy

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    The failure of matrix metalloproteinase (MMP) inhibitor drug clinical trials in cancer was partly due to the inadvertent inhibition of MMP antitargets that counterbalanced the benefits of MMP target inhibition. We explore how MMP inhibitor drugs might be developed to achieve potent selectivity for validated MMP targets yet therapeutically spare MMP antitargets that are critical in host protection

    Evaluation of bacteriophage as an adjunct therapy for treatment of peri-prosthetic joint infection caused by Staphylococcus aureus

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    Phage therapy offers a potential alternate strategy for the treatment of peri-prosthetic joint infection (PJI), particularly where limited effective antibiotics are available. We undertook preclinical trials to investigate the therapeutic efficacy of a phage cocktail, alone and in combination with vancomycin, to reduce bacterial numbers within the infected joint using a clinically-relevant model of Staphylococcus aureus-induced PJI. Infected animals were randomised to 4 treatment groups, with treatment commencing 21-days post-surgery: bacteriophage alone, vancomycin alone, bacteriophage and vancomycin, and sham. At day 28 post-surgery, animals were euthanised for microbiological and immunological assessment of implanted joints. Treatment with phage alone or vancomycin alone, led to 5-fold and 6.2-fold reductions, respectively in bacterial load within peri-implant tissue compared to shamtreated animals. Compared to sham-treated animals, a 22.5-fold reduction in S. aureus burden was observed within joint tissue of animals that were administered phage in combination with vancomycin, corresponding with decreased swelling in the implanted knee. Microbiological data were supported by evidence of decreased inflammation within the joints of animals administered phage in combination with vancomycin, compared to sham-treated animals. Our findings provide further support for phage therapy as a tolerable and effective adjunct treatment for PJI

    Mechanisms of action of systemic antibiotics used in periodontal treatment and mechanisms of bacterial resistance to these drugs

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    Fault’s hydraulic diffusivity enhancement during injection induced fault reactivation: application of pore pressure diffusion inversions to laboratory injection experiments

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    International audienceIn situ observations of fluid induced fault slip reactivation, as well as the analysis of induced seismicity have demonstrated the complexity of fluid–fault interactions under geological conditions. If fluid flow commonly reactivates faults in the form of aseismic slip or earthquakes, the resulting shear deformation causes strong modifications of the hydraulic properties. In this context, the relationship between slip front and fluid front on deep faults remains not fully understood. In this study, we investigate shear induced fluid flow and hydraulic diffusivity enhancement during fracture shearing in the laboratory. We use a series of injection reactivation tests, conducted under triaxial conditions, at different confining pressures (30, 60 and 95 MPa). The evolution of the fluid pressure along the saw-cut Andesite rock sample was monitored by two pressure sensors, at two opposite locations of the experimental fault. We estimate the history of the effective hydraulic diffusivity (and its associated uncertainties) governing the experimental fault, using the pressure history at two points on the fault. For this, we develop a deterministic and a probabilistic inversion procedure, which is able to reproduce the experimental data for a wide time range of the different experiments. In this study, the hydraulic diffusivity increases by one order of magnitude through the injection experiment. Hydraulic diffusivity changes are mainly governed by the reduction of the effective normal stress acting on the fault plane, with a second-order effect of the shear slip

    Self-assembly of long chain fatty acids: Effect of a methyl branch

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    The morphology and molecular conformation of monolayers of straight chain and methyl-branched fatty acids have been investigated by VSFS and AFM, revealing domains in the latter case, due to inverse micellar packing constraints.</p

    Characteristics and outcomes of reversed patients admitted to an emergency department for VKA-related intramuscular hematoma

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    Background According to the International Society on Thrombosis and Haemostasis (ISTH), intramuscular hematoma without other severity criteria is not considered a major bleeding. Objectives: In a large cohort of reversed vitamin K antagonist (VKA) patients admitted to the emergency unit for muscular hematoma, we assess frequency, severity, and anticoagulation management based on whether ISTH criteria were met or not. Materials and methods We performed a retrospective single-center study involving patients admitted to an emergency unit for VKA-induced intramuscular hematoma whose bleeding was reversed with prothrombin complex concentrates. Results During the study period, 631 VKA-induced bleeding events occurred in our emergency unit, of which 73 (11.6%) were intramuscular hematomas and half met ISTH criteria. The mean age was 75.5 years (95% CI = 72.6–78.3). Admission blood tests showed that patients with ISTH criteria had higher international normalized ratio (7.0 ± 4.6 vs. 4.1 ± 3.0, p = 0.002) and lower hemoglobin (8.1 ± 1.8 vs. 11.9 ± 2.2, p < 0.001) than those without. Patients with ISTH criteria were more likely to have intramuscular hematoma in the iliopsoas, gluteal, and pectoral muscles than those without. Interestingly, two-thirds of rectus sheath hematomas involved patients without ISTH criteria. However, patients with or without ISTH criteria exhibited a similar hospitalization duration and rate of re-bleeding. Conclusion We showed that half of the patients admitted with intramuscular hematoma could not be qualified as having ISTH-criteria major bleeding. Interestingly, these patients displayed a similar hospitalization duration and rate of re-bleeding to those with ISTH-criteria major bleeding
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