617 research outputs found
Adaptive estimation of the density matrix in quantum homodyne tomography with noisy data
In the framework of noisy quantum homodyne tomography with efficiency
parameter , we propose a novel estimator of a quantum state
whose density matrix elements decrease like ,
for fixed , and . On the contrary to previous works,
we focus on the case where , and are unknown. The procedure
estimates the matrix coefficients by a projection method on the pattern
functions, and then by soft-thresholding the estimated coefficients.
We prove that under the -loss our procedure is adaptive
rate-optimal, in the sense that it achieves the same rate of conversgence as
the best possible procedure relying on the knowledge of . Finite
sample behaviour of our adaptive procedure are explored through numerical
experiments
State estimation in quantum homodyne tomography with noisy data
In the framework of noisy quantum homodyne tomography with efficiency
parameter , we propose two estimators of a quantum state whose
density matrix elements decrease like , for
fixed known and . The first procedure estimates the matrix
coefficients by a projection method on the pattern functions (that we introduce
here for ), the second procedure is a kernel estimator of the
associated Wigner function. We compute the convergence rates of these
estimators, in risk
Assessment of the main stone fruit viruses and viroids in Algeria
In order to improve the sanitary status of the propagating material of stone fruits, a field survey was conducted to assess the main viruses and viroids affecting stone fruits in selected growing areas and their distribution on the collected material by using serological and molecular detection methods.Serological assays were carried out to detect Plum pox virus (PPV), Prunus necrotic ring spot virus (PNRSV), Prune dwarf virus (PDV), Apple mosaic virus (ApMV) and Apple chlorotic leaf spot virus (ACLSV). Moreover, tissue-print hybridization was performed to detect Peach latent mosaic viroid (PLMVd) and Hop stunt viroid (HSVd).Among nearly 2000 trees tested, no PPV infection was detected, while 14% of them positively reacted to at least one virus. The highest infection rate (18%) was reported in both nurseries and commercial orchards. PNRSV was the most detected virus (9%), followed by ApMV (3%) and PDV (1.5%). Cherry was the most infected species (20%). As for viroids, a high infection rate was recorded for PLMVd (9%) and HSVd (5%); the highest infection rate was reported in mother blocks and varietal collections.Keywords: Algeria, Prunus, virus, viroids, ELISA, tissue-print hybridization, sanitary statu
Circulating microparticles as biomarkers of stroke: A focus on the value of endothelial- and platelet-derived microparticles.
Stroke is one of the leading causes of mortality and disability worldwide. Numerous pathophysiological mechanisms involving blood vessels, coagulation and inflammation contribute to the vascular occlusion. Perturbations in these pathways can be detected by numerous methods including changes in endoplasmic membrane remodeling and rearrangement leading to the shedding of microparticles (MPs) from various cellular origins in the blood. MPs are small membrane-derived vesicles that are shed from nearly all cells in the body in resting state or upon stimulation. MPs act as biological messengers to transfer information to adjacent and distant cells thus regulating various biological processes. MPs may be important biomarkers and tools for the identification of the risk and diagnosis of cerebrovascular diseases. Endothelial activation and dysfunction and altered thrombotic responses are two of the main features predisposing to stroke. Endothelial MPs (EMPs) have been recognized as both biomarkers and effectors of endothelial cell activation and injury while platelet-derived MPs (PMPs) carry a strong procoagulant potential and are activated in thrombotic states. Therefore, we reviewed here the role of EMPs and PMPs as biomarkers of stroke. Most studies reported high circulating levels of EMPs and PMPs in addition to other cell origins in stroke patients and have been linked to stroke severity, the size of infarction, and prognosis. The identification and quantification of EMPs and PMPs may thus be useful for the diagnosis and management of stroke.NPRP award (NPRP8-1750-3-360) from Qatar National Research Fund (a member of Qatar Foundation) and a Qatar University high collaborative grant (QUCG-CPH-2018\2019-2
Exploring the properties of the phases of QCD matter - research opportunities and priorities for the next decade
This document provides a summary of the discussions during the recent joint
QCD Town Meeting at Temple University of the status of and future plans for the
research program of the relativistic heavy-ion community. A list of compelling
questions is formulated, and a number of recommendations outlining the greatest
research opportunities and detailing the research priorities of the heavy-ion
community, voted on and unanimously approved at the Town Meeting, are
presented. They are supported by a broad discussion of the underlying physics
and its relation to other subfields. Areas of overlapping interests with the
"QCD and Hadron Structure" ("cold QCD") subcommunity, in particular the
recommendation for the future construction of an Electron-Ion Collider, are
emphasized. The agenda of activities of the "hot QCD" subcommunity at the Town
Meeting is attached.Comment: 34 pages of text, 254 references,16 figure
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