252 research outputs found

    SU(3) Quantum Interferometry with single-photon input pulses

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    We develop a framework for solving the action of a three-channel passive optical interferometer on single-photon pulse inputs to each channel using SU(3) group-theoretic methods, which can be readily generalized to higher-order photon-coincidence experiments. We show that features of the coincidence plots vs relative time delays of photons yield information about permanents, immanants, and determinants of the interferometer SU(3) matrix

    Lost and found: the radial quantum number of Laguerre-Gauss modes

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    We introduce an operator linked with the radial index in the Laguerre-Gauss modes of a two-dimensional harmonic oscillator in cylindrical coordinates. We discuss ladder operators for this variable, and confirm that they obey the commutation relations of the su(1,1) algebra. Using this fact, we examine how basic quantum optical concepts can be recast in terms of radial modes.Comment: Some minor typos fixed

    Generalized multi-photon quantum interference

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    Non-classical interference of photons lies at the heart of optical quantum information processing. This effect is exploited in universal quantum gates as well as in purpose-built quantum computers that solve the BosonSampling problem. Although non-classical interference is often associated with perfectly indistinguishable photons this only represents the degenerate case, hard to achieve under realistic experimental conditions. Here we exploit tunable distinguishability to reveal the full spectrum of multi-photon non-classical interference. This we investigate in theory and experiment by controlling the delay times of three photons injected into an integrated interferometric network. We derive the entire coincidence landscape and identify transition matrix immanants as ideally suited functions to describe the generalized case of input photons with arbitrary distinguishability. We introduce a compact description by utilizing a natural basis which decouples the input state from the interferometric network, thereby providing a useful tool for even larger photon numbers

    Fungal and Bacterial Loads: Noninvasive Inflammatory Bowel Disease Biomarkers for the Clinical Setting

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    Malaltia inflamatòria intestinal; Càrrega microbiana; PrediccióEnfermedad inflamatoria intestinal; Carga microbiana; PredicciónInflammatory bowel disease; Microbial load; PredictionMicrobiome sequence data have been used to characterize Crohn's disease (CD) and ulcerative colitis (UC). Based on these data, we have previously identified microbiomarkers at the genus level to predict CD and CD relapse. However, microbial load was underexplored as a potential biomarker in inflammatory bowel disease (IBD). Here, we sought to study the use of fungal and bacterial loads as biomarkers to detect both CD and UC and CD and UC relapse. We analyzed the fecal fungal and bacterial loads of 294 stool samples obtained from 206 participants using real-time PCR amplification of the ITS2 region and the 16S rRNA gene, respectively. We combined the microbial data with demographic and standard laboratory data to diagnose ileal or ileocolonic CD and UC and predict disease relapse using the random forest algorithm. Fungal and bacterial loads were significantly different between healthy relatives of IBD patients and nonrelated healthy controls, between CD and UC patients in endoscopic remission, and between UC patients in relapse and non-UC individuals. Microbial load data combined with demographic and standard laboratory data improved the performance of the random forest models by 18%, reaching an average area under the receiver operating characteristic curve (AUC) of 0.842 (95% confidence interval [CI], 0.65 to 0.98), for IBD diagnosis and enhanced CD and UC discrimination and CD and UC relapse prediction. Our findings show that fecal fungal and bacterial loads could provide physicians with a noninvasive tool to discriminate disease subtypes or to predict disease flare in the clinical setting. IMPORTANCE Next-generation sequence data analysis has allowed a better understanding of the pathophysiology of IBD, relating microbiome composition and functions to the disease. Microbiome composition profiling may provide efficient diagnosis and prognosis tools in IBD. However, the bacterial and fungal loads of the fecal microbiota are underexplored as potential biomarkers of IBD. Ulcerative colitis (UC) patients have higher fecal fungal and bacterial loads than patients with ileal or ileocolonic CD. CD patients who relapsed harbor more-unstable fungal and bacterial loads than those of relapsed UC patients. Fecal fungal and bacterial load data improved prediction performance by 18% for IBD diagnosis based solely on clinical data and enhanced CD and UC discrimination and prediction of CD and UC relapse. Combined with existing laboratory biomarkers such as fecal calprotectin and C-reactive protein (CRP), microbial loads may improve the diagnostic accuracy of IBD and of ileal CD and UC disease activity and prediction of UC and ileal CD clinical relapse.This work was funded by Instituto de Salud Carlos III, grant PI17/00614, cofinanced by the European Regional Development Fund (ERDF) and by the PERIS (SLT002/16). F. Casellas has received research funding from AbbVie, Ferring, MSD, Shire, and Zambon and speaker fees from AbbVie, Chiesi, Ferring, Gebro, MSD, Shire, Takeda, and Zambon. S. Vermeire has received grant support from AbbVie, MSD, Pfizer, J&J, and Takeda; received speaker fees from AbbVie, MSD, Takeda, Ferring, Dr. Falk Pharma, Hospira, Pfizer Inc., and Tillots; and served as a consultant for AbbVie, MSD, Takeda, Ferring, Genentech/Roche, Robarts clinical trials, Gilead, Celgene, Prometheus, Avaxia, Prodigest, Shire, Pfizer Inc, Galapagos, Mundipharma, Hospira, Celgene, Second Genome, and Janssen. C. Manichanh has received financial support for research from Danone

    Exchange Gate on the Qudit Space and Fock Space

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    We construct the exchange gate with small elementary gates on the space of qudits, which consist of three controlled shift gates and three "reverse" gates. This is a natural extension of the qubit case. We also consider a similar subject on the Fock space, but in this case we meet with some different situation. However we can construct the exchange gate by making use of generalized coherent operator based on the Lie algebra su(2) which is a well--known method in Quantum Optics. We moreover make a brief comment on "imperfect clone".Comment: Latex File, 12 pages. I could solve the problems in Sec. 3 in the preceding manuscript, so many corrections including the title were mad

    Performance of cryptococcal antigen lateral flow assay in serum, cerebrospinal fluid, whole blood, and urine in HIV-infected patients with culture-proven cryptococcal meningitis admitted at a Brazilian referral center

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    Cryptococcal meningitis is the most common cause of opportunistic meningitis in HIV-infected patients in Brazil and causes unacceptable high mortality rates. In this study, HIV-infected patients with a first episode of culture-proven cryptococcal meningitis in cerebrospinal fluid (CSF) were prospectively included in order to evaluate sensitivity of cryptococcal antigen (CrAg) lateral flow assay (LFA) in serum, CSF, whole blood (fingerstick), and fresh urine. In addition, HIV-infected patients with other neurological confirmed diseases were included in order to evaluate the specificity of CrAg LFA in serum. Twenty patients with cryptococcal meningitis were included and in 19 of them, CrAg LFA in CSF, serum, and whole blood were positive (95% sensitivity). In 18 patients, India ink test was positive in CSF (90% sensitivity), and in 16 cases, CrAg LFA was positive in urine (80% sensitivity). Thirty-six HIV-infected patients with other neurological diseases had negative results of CrAg LFA in serum (100% specificity). In conclusion, CrAg LFA in serum, CSF, and whole blood showed high sensitivity and specificity. Whole blood CrAg LFA seems to be a good and reliable strategy to improve AIDS-related cryptococcal meningitis diagnosis in Brazil

    Cetacean <i>Morbillivirus</i>: Current knowledge and future directions

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    We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported

    The Benefits Conferred by Radial Access for Cardiac Catheterization Are Offset by a Paradoxical Increase in the Rate of Vascular Access Site Complications With Femoral Access The Campeau Radial Paradox

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    AbstractObjectivesThe purpose of this study was to assess whether the benefits conferred by radial access (RA) at an individual level are offset by a proportionally greater incidence of vascular access site complications (VASC) at a population level when femoral access (FA) is performed.BackgroundThe recent widespread adoption of RA for cardiac catheterization has been associated with increased rates of VASCs when FA is attempted.MethodsLogistic regression was used to calculate the adjusted VASC rate in a contemporary cohort of consecutive patients (2006 to 2008) where both RA and FA were used, and compared it with the adjusted VASC rate observed in a historical control cohort (1996 to 1998) where only FA was used. We calculated the adjusted attributable risk to estimate the proportion of VASC attributable to the introduction of RA in FA patients of the contemporary cohort.ResultsA total of 17,059 patients were included. At a population level, the VASC rate was higher in the overall contemporary cohort compared with the historical cohort (adjusted rates: 2.91% vs. 1.98%; odds ratio [OR]: 1.48, 95% confidence interval [CI]: 1.17 to 1.89; p = 0.001). In the contemporary cohort, RA patients experienced fewer VASC than FA patients (adjusted rates: 1.44% vs. 4.19%; OR: 0.33, 95% CI: 0.23 to 0.48; p < 0.001). We observed a higher VASC rate in FA patients in the contemporary cohort compared with the historical cohort (adjusted rates: 4.19% vs. 1.98%; OR: 2.16, 95% CI: 1.67 to 2.81; p < 0.001). This finding was consistent for both diagnostic and therapeutic catheterizations separately. The proportion of VASCs attributable to RA in the contemporary FA patients was estimated at 52.7%.ConclusionsIn a contemporary population where both RA and FA were used, the safety benefit associated with RA is offset by a paradoxical increase in VASCs among FA patients. The existence of this radial paradox should be taken into consideration, especially among trainees and default radial operators
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