2,760 research outputs found

    Chern-Simons Solitons, Chiral Model, and (affine) Toda Model on Noncommutative Space

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    We consider the Dunne-Jackiw-Pi-Trugenberger model of a U(N) Chern-Simons gauge theory coupled to a nonrelativistic complex adjoint matter on noncommutative space. Soliton configurations of this model are related the solutions of the chiral model on noncommutative plane. A generalized Uhlenbeck's uniton method for the chiral model on noncommutative space provides explicit Chern-Simons solitons. Fundamental solitons in the U(1) gauge theory are shaped as rings of charge `n' and spin `n' where the Chern-Simons level `n' should be an integer upon quantization. Toda and Liouville models are generalized to noncommutative plane and the solutions are provided by the uniton method. We also define affine Toda and sine-Gordon models on noncommutative plane. Finally the first order moduli space dynamics of Chern-Simons solitons is shown to be trivial.Comment: latex, JHEP style, 23 pages, no figur

    The Electric Dipole Moment of the Nucleons in Holographic QCD

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    We introduce the strong CP-violation in the framework of AdS/QCD model and calculate the electric dipole moments of nucleons as well as the CP-violating pion-nucleon coupling. Our holographic estimate of the electric dipole moments gives for the neutron d_n=1.08 X 10^{-16} theta (e cm), which is comparable with previous estimates. We also predict that the electric dipole moment of the proton should be precisely the minus of the neutron electric dipole moment, thus leading to a new sum rule on the electric dipole moments of baryons.Comment: 22 pages, no figures. v2: A reference and an acknowledgment added. v3: One more reference, to appear in JHE

    NS1 Specific CD8(+) T-Cells with Effector Function and TRBV11 Dominance in a Patient with Parvovirus B19 Associated Inflammatory Cardiomyopathy

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    Background: Parvovirus B19 (B19V) is the most commonly detected virus in endomyocardial biopsies (EMBs) from patients with inflammatory cardiomyopathy (DCMi). Despite the importance of T-cells in antiviral defense, little is known about the role of B19V specific T-cells in this entity. Methodology and Principal Findings: An exceptionally high B19V viral load in EMBs (115,091 viral copies/mg nucleic acids), peripheral blood mononuclear cells (PBMCs) and serum was measured in a DCMi patient at initial presentation, suggesting B19V viremia. The B19V viral load in EMBs had decreased substantially 6 and 12 months afterwards, and was not traceable in PBMCs and the serum at these times. Using pools of overlapping peptides spanning the whole B19V proteome, strong CD8(+) T-cell responses were elicited to the 10-amico-acid peptides SALKLAIYKA (19.7% of all CD8(+) cells) and QSALKLAIYK (10%) and additional weaker responses to GLCPHCINVG (0.71%) and LLHTDFEQVM (0.06%). Real-time RT-PCR of IFN gamma secretion-assay-enriched T-cells responding to the peptides, SALKLAIYKA and GLCPHCINVG, revealed a disproportionately high T-cell receptor Vbeta (TRBV) 11 expression in this population. Furthermore, dominant expression of type-1 (IFN gamma, IL2, IL27 and Tbet) and of cytotoxic T-cell markers (Perforin and Granzyme B) was found, whereas gene expression indicating type-2 (IL4, GATA3) and regulatory T-cells (FoxP3) was low. Conclusions: Our results indicate that B19V Ag-specific CD8(+) T-cells with effector function are involved in B19V associated DCMi. In particular, a dominant role of TRBV11 and type-1/CTL effector cells in the T-cell mediated antiviral immune response is suggested. The persistence of B19V in the endomyocardium is a likely antigen source for the maintenance of CD8(+) T-cell responses to the identified epitopes

    Obstetric and Perinatal Outcomes in Type 1 Diabetic Pregnancies: A large, population-based study

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    The aim of this epidemiological study was to elucidate whether in recent years, obstetric and perinatal outcomes in pregnancies complicated by type 1 diabetes (T1DM) have improved or not. The objective was also to identify possible risk factors for adverse outcome for the mother, fetus and the newborn. All studies (Ι-ΙV) included in this thesis were based on national data from the Swedish Medical Birth Registry, during the time period 1991-2007. In 5,089 type 1 diabetic pregnancies and 1.2 million controls we found significantly increased risks of all adverse outcomes in women with T1DM: adjusted odds ratios: severe preeclampsia: 4.47 (3.77-5.31), Caesarean delivery: 5.31 (4.97-5.69), stillbirth: 3.34 (2.46- 4.55), perinatal mortality: 3.29 (2.50-4.33), major malformations: 2.50 (2.13-2.94) and large for gestational age: LGA (birth weight ≥ +2 SD): 11.45 (10.61-12.36) (study Ι). The markedly elevated odds of an LGA outcome inspired us to characterize in more detail the distribution of birth size in a large national cohort of T1DM offspring (study ΙΙ n=3,705) and to investigate if disproportionate body composition was associated with increased risk of perinatal complications (study ΙΙΙ n=3,517). Percentiles for birth weight (BW), birth length (BL) and head circumference (HC) were formed based on data from non-diabetic pregnancies and standard deviation scores (SDS) were calculated for BW, BL and HC. The ponderal index (PI: BW in grams/(BL in cm) ³ was used as a proxy for body proportionality and fat mass and we defined disproportionate/overweight LGA as infants with a BW and PI ≥90th percentile for gestational age and gender. The distributions of BW, BL and HC were all unimodal but significantly shifted to the right of the normal reference. The distribution for BW was most markedly shifted to the right. 47% were LGA with a BW ≥90th adjusted percentile. The mean ponderal index (PI) was significantly increased and 46% of LGA infants were disproportionate with a PI ≥90th percentile and thus overweight at birth. A novel and unexpected finding was that fetal macrosomia was more pronounced in preterm and female infants (study ΙΙ). Surprisingly, neonatal outcome was independent of body proportionality in appropriate for gestational age (AGA) and LGA infants. The risk of adverse outcome was significantly increased in LGA compared with AGA infants born at term (study ΙΙΙ). There was a significant interaction between gestational age and body weight with prematurity overriding LGA as a risk factor for neonatal morbidity in moderately preterm infants. In study ΙV, we examined the risk of adverse outcome in relation to pre-pregnancy body mass index in a national cohort of 3,457 T1DM pregnancies compared to 764,498 non-diabetic pregnancies. Maternal overweight/obesity increases the risk of adverse outcome in both women with and without T1DM. Within the T1DM cohort, obesity was associated with increased odds of major malformations adjusted OR: 1.77 (1.18-2.65) and preeclampsia adjusted OR: 1.74 (1.35-2.25). T1DM was a significant effect modifier of the association between BMI and major malformations, preeclampsia, LGA and neonatal overweight. Conclusion: In spite of major improvements in the management of type 1 diabetic pregnancies over the years, the present findings clearly demonstrate that T1DM pregnancies still are associated with significantly increased risk of adverse outcomes. An important observation is the rising incidence of LGA infants, which partly can be attributed to a concomitant increase in maternal BMI. This development is worrying as LGA infants face an excess risk of both perinatal and future complications as compared to normal sized infants. The novel and unexpected finding of a gender difference in fetal macrosomia requires further investigations

    Global organization of metabolic fluxes in the bacterium, Escherichia coli

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    Cellular metabolism, the integrated interconversion of thousands of metabolic substrates through enzyme-catalyzed biochemical reactions, is the most investigated complex intercellular web of molecular interactions. While the topological organization of individual reactions into metabolic networks is increasingly well understood, the principles governing their global functional utilization under different growth conditions pose many open questions. We implement a flux balance analysis of the E. coli MG1655 metabolism, finding that the network utilization is highly uneven: while most metabolic reactions have small fluxes, the metabolism's activity is dominated by several reactions with very high fluxes. E. coli responds to changes in growth conditions by reorganizing the rates of selected fluxes predominantly within this high flux backbone. The identified behavior likely represents a universal feature of metabolic activity in all cells, with potential implications to metabolic engineering.Comment: 15 pages 4 figure

    Introduction to the functional RG and applications to gauge theories

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    These lectures contain an introduction to modern renormalization group (RG) methods as well as functional RG approaches to gauge theories. In the first lecture, the functional renormalization group is introduced with a focus on the flow equation for the effective average action. The second lecture is devoted to a discussion of flow equations and symmetries in general, and flow equations and gauge symmetries in particular. The third lecture deals with the flow equation in the background formalism which is particularly convenient for analytical computations of truncated flows. The fourth lecture concentrates on the transition from microscopic to macroscopic degrees of freedom; even though this is discussed here in the language and the context of QCD, the developed formalism is much more general and will be useful also for other systems.Comment: 60 pages, 14 figures, Lectures held at the 2006 ECT* School "Renormalization Group and Effective Field Theory Approaches to Many-Body Systems", Trento, Ital

    Icebergs in the North Atlantic: Modelling circulation changes and glacio-marine deposition

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    In order to investigate meltwater events in the North Atlantic, a simple iceberg generation, drift, and melting routine was implemented in a high-resolution OGCM. Starting from the modelled last glacial state, every 25th day cylindrical model icebergs 300 meters high were released at 32 specific points along the coasts. Icebergs launched at the Barents Shelf margin spread a light meltwater lid over the Norwegian and Greenland Seas, shutting down the deep convection and the anti-clockwise circulation in this area. Due to the constraining ocean circulation, the icebergs produce a tongue of relatively cold and fresh water extending eastward from Hudson Strait that must develop at this location, regardless of iceberg origin. From the total amount of freshwater inferred by the icebergs, the thickness of the deposited IRD could be calculated in dependance of iceberg sediment concentration. In this way, typical extent and thickness of Heinrich layers could be reproduced, running the model for 250 years of steady state with constant iceberg meltwater inflow

    Higgs Portal to Visible Supersymmetry Breaking

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    We propose a supersymmetric extension of the standard model whose Higgs sector induces a spontaneous supersymmetry breaking by itself. Unlike the minimal extension, the current Higgs mass bound can be evaded even at the tree-level without the help of the soft breaking terms due to the usual hidden sector, as is reminiscent of the next to minimal case. We also have a possibly light pseudo-goldstino in our visible sector in addition to extra Higgs particles, both of which stem from supersymmetry breaking dynamics. In such a setup of visible supersymmetry breaking, we may see a part of supersymmetry breaking dynamics rather directly in future experiments.Comment: 23 pages, 6 figures, references adde

    A model to determine staff levels, cost, and productivity of hospital units

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    A methodology is presented with examples of the productivity, the staffing required, the resultant productivity, and costs that can be obtained for hospital units that are subject to random work demands such as laboratory, radiology, physical therapy, and nuclear medicine. The methodology assumes that the hospital has a labor productivity system that produces the RVUs or earned hours of work accomplished daily by shift. Factors considered are the distribution of the capabilities of the work force, the fatigue and delay allowances of the work standards, the quality of the work standards, the maximum amount of overtime that people will be asked to work, staffing policies such as constant or different staffing levels for each day of the week, and worker selection processes. Predicted results are compared with present practice, which indicates that substantial cost reductions can occur with the use of the methodology.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44987/1/10916_2004_Article_BF00996347.pd
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