192 research outputs found
A systematic review and meta-analysis of the prevalence of human cytomegalovirus shedding in seropositive pregnant women.
The detection of human cytomegalovirus (HCMV) in an individual's bodily fluid by culture techniques or through HCMV DNA detection by polymerase chain reaction, is known as HCMV shedding. Human cytomegalovirus shedding has the potential to transmit HCMV infection, where an individual can become infected with HCMV through contact with the bodily fluid of another individual containing HCMV. Human cytomegalovirus shedding can occur in primary infection and in non-primary infection for individuals with prior infection (HCMV seropositive). Human cytomegalovirus infection causes few or no symptoms in a pregnant woman, but can cause significant harm to her foetus if congenital CMV (cCMV) infection occurs. The association between HCMV shedding in HCMV seropositive pregnant women and the vertical transmission of HCMV to result in cCMV infection is poorly investigated, challenged by a limited understanding of the distribution of HCMV shedding in HCMV seropositive pregnant women. We systematically reviewed the published literature to describe the prevalence of HCMV shedding in HCMV seropositive women during pregnancy up to delivery. This analysis identified nine studies that met our eligibility criteria. In these studies, the prevalence of HCMV shedding in any bodily fluid of HCMV seropositive women during pregnancy and at delivery ranged from 0% to 42.5%. A meta-analysis, performed on six of the nine studies with suitable sample sizes, estimated a pooled prevalence of 21.5% [95% CI 12.7%,30.3%]. To our knowledge, this is the first review to systematically search the literature to summarise the prevalence of HCMV shedding in HCMV seropositive pregnant women. These estimates can help in the development of disease burden models and therapeutic or preventative strategies against cCMV infection in the context of non-primary maternal HCMV infection
Integer Least-squares Theory for the GNSS Compass
Global navigation satellite system (GNSS) carrier phase integer ambiguity resolution is the key to high-precision positioning and attitude determination. In this contribution, we develop new integer least-squares (ILS) theory for the GNSS compass model, together with efficient integer search strategies. It extends current unconstrained ILS theory to the nonlinearly constrained case, an extension that is particularly suited for precise attitude determination. As opposed to current practice, our method does proper justice to the a priori given information. The nonlinear baseline constraint is fully integrated into the ambiguity objective function, thereby receiving a proper weighting in its minimization and providing guidance for the integer search. Different search strategies are developed to compute exact and approximate solutions of the nonlinear constrained ILS problem. Their applicability depends on the strength of the GNSS model and on the length of the baseline. Two of the presented search strategies, a global and a local one, are based on the use of an ellipsoidal search space. This has the advantage that standard methods can be applied. The global ellipsoidal search strategy is applicable to GNSS models of sufficient strength, while the local ellipsoidal search strategy is applicable to models for which the baseline lengths are not too small. We also develop search strategies for the most challenging case, namely when the curvature of the non-ellipsoidal ambiguity search space needs to be taken into account. Two such strategies are presented, an approximate one and a rigorous, somewhat more complex, one. The approximate one is applicable when the fixed baseline variance matrix is close to diagonal. Both methods make use of a search and shrink strategy. The rigorous solution is efficiently obtained by means of a search and shrink strategy that uses non-quadratic, but easy-to-evaluate, bounding functions of the ambiguity objective function. The theory presented is generally valid and it is not restricted to any particular GNSS or combination of GNSSs. Its general applicability also applies to the measurement scenarios (e.g. single-epoch vs. multi-epoch, or single-frequency vs. multi-frequency). In particular it is applicable to the most challenging case of unaided, single frequency, single epoch GNSS attitude determination. The success rate performance of the different methods is also illustrated
Ratio of the Isolated Photon Cross Sections at \sqrt{s} = 630 and 1800 GeV
The inclusive cross section for production of isolated photons has been
measured in \pbarp collisions at GeV with the \D0 detector at
the Fermilab Tevatron Collider. The photons span a transverse energy ()
range from 7-49 GeV and have pseudorapidity . This measurement is
combined with to previous \D0 result at GeV to form a ratio
of the cross sections. Comparison of next-to-leading order QCD with the
measured cross section at 630 GeV and ratio of cross sections show satisfactory
agreement in most of the range.Comment: 7 pages. Published in Phys. Rev. Lett. 87, 251805, (2001
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
The role of power in financial statement fraud schemes
In this paper, we investigate a large-scale financial statement fraud to better understand the process by which individuals are recruited to participate in financial statement fraud schemes. The case reveals that perpetrators often use power to recruit others to participate in fraudulent acts. To illustrate how power is used, we propose a model, based upon the classical French and Raven taxonomy of power, that explains how one individual influences another individual to participate in financial statement fraud. We also provide propositions for future research
CD4+ Regulatory and Effector/Memory T Cell Subsets Profile Motor Dysfunction in Parkinsonâs Disease
Animal models and clinical studies have linked the innate and adaptive immune system to the pathology of Parkinsonâs disease (PD). Despite such progress, the specific immune responses that influence disease progression have eluded investigators. Herein, we assessed relationships between T cell phenotype and function with PD progression. Peripheral blood lymphocytes from two separate cohorts, a discovery cohort and a validation cohort, totaling 113 PD patients and 96 age- and environment-matched caregivers were examined by flow cytometric analysis and T cell proliferation assays. Increased effector/memory T cells (Tem), defined as CD45RO+ and FAS+ CD4+ T cells and decreased CD31+ and Îą4β7+ CD4+ T cells were associated with progressive Unified Parkinsonâs Disease Rating Scale III scores. However, no associations were seen between immune biomarkers and increased age or disease duration. Impaired abilities of regulatory T cells (Treg) from PD patients to suppress effector T cell function was observed. These data support the concept that chronic immune stimulation, notably Tem activation and Treg dysfunction is linked to PD pathobiology and disease severity, but not disease duration. The association of T cell phenotypes with motor symptoms provides fresh avenues for novel biomarkers and therapeutic designs
Combined Tevatron upper limit on gg->H->W+W- and constraints on the Higgs boson mass in fourth-generation fermion models
Report number: FERMILAB-PUB-10-125-EWe combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg->H->W+W- in p=pbar collisions at the Fermilab Tevatron Collider at sqrt{s}=1.96 TeV. With 4.8 fb-1 of integrated luminosity analyzed at CDF and 5.4 fb-1 at D0, the 95% Confidence Level upper limit on \sigma(gg->H) x B(H->W+W-) is 1.75 pb at m_H=120 GeV, 0.38 pb at m_H=165 GeV, and 0.83 pb at m_H=200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.We combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process ggâHâW+W- in ppĚ
collisions at the Fermilab Tevatron Collider at âs=1.96ââTeV. With 4.8ââfb-1 of integrated luminosity analyzed at CDF and 5.4ââfb-1 at D0, the 95% confidence level upper limit on Ď(ggâH)ĂB(HâW+W-) is 1.75 pb at mH=120ââGeV, 0.38 pb at mH=165ââGeV, and 0.83 pb at mH=200ââGeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% confidence level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.Peer reviewe
Aligning the CMS Muon Chambers with the Muon Alignment System during an Extended Cosmic Ray Run
Peer reviewe
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