2,158 research outputs found

    Z' studies at the LHC: an update

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    We reanalyse the potential of the LHC to discover new ZZ' gauge bosons and to discriminate between various theoretical models. Using a fast LHC detector simulation, we have investigated how well the characteristics of ZZ' bosons from different models can be measured. For this analysis we have combined the information coming from the cross section measurement, which provides also the ZZ' mass and total width, the forward-backward charge asymmetries on- and off-peak, and the ZZ' rapidity distribution, which is sensitive to its uuˉu \bar{u} and ddˉd \bar{d} couplings. We confirm that new ZZ' bosons can be observed in the process ppZl+lpp \to Z' \to l^+ l^-, up to masses of about 5 TeV for an integrated luminosity of 100 fb1^{-1}. The off- and on-resonance peak forward-backward charge asymmetries AFBlA_{\rm FB}^{l} show that interesting statistical accuracies can be obtained up to ZZ' masses of the order of 2 TeV. We then show how the different experimental observables allow for a diagnosis of the ZZ' boson and the distinction between the various considered models.Comment: 14 pages, latex, 6 figure

    Histone deacetylase inhibition sensitizes osteosarcoma to heavy ion radiotherapy

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    Background: Minimal improvements in treatment or survival of patients with osteosarcoma have been achieved during the last three decades. Especially in the case of incomplete tumor resection, prognosis remains poor. Heavy ion radiotherapy (HIT) and modern anticancer drugs like histone deacetylase inhibitors (HDACi) have shown promising effects in osteosarcoma in vitro. In this study, we tested the effect of HIT and the combination of HIT and the HDACi suberoylanilide hydroxamic acid (SAHA) in a xenograft mouse model. Methods: Osteosarcoma xenografts were established by subcutaneous injection of KHOS-24OS cells and treated with either vehicle (DMSO), SAHA, HIT or HIT and SAHA. Tumor growth was determined and tumor necrosis, proliferation rate, apoptotic rate as well as vessel density were evaluated. Results: Here, we show that the combination of HIT and SAHA induced a significant delay of tumor growth through increased rate of apoptosis, increased expression of p53 and p21Waf1/Cip1, inhibition of proliferation and angiogenesis compared to tumors treated with HIT only. Conclusion: HIT and in particular the combination of HIT and histone deacetylase inhibition is a promising treatment strategy in OS and may be tested in clinical trials

    Establishment of a patient-derived orthotopic osteosarcoma mouse model

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    Background: Osteosarcoma (OS) is the most common pediatric primary malignant bone tumor. As the prognosis for patients following standard treatment did not improve for almost three decades, functional preclinical models that closely reflect important clinical cancer characteristics are urgently needed to develop and evaluate new treatment strategies. The objective of this study was to establish an orthotopic xenotransplanted mouse model using patient-derived tumor tissue. Methods: Fresh tumor tissue from an adolescent female patient with osteosarcoma after relapse was surgically xenografted into the right tibia of 6 immunodeficient BALB/c Nu/Nu mice as well as cultured into medium. Tumor growth was serially assessed by palpation and with magnetic resonance imaging (MRI). In parallel, a primary cell line of the same tumor was established. Histology and high-resolution array-based comparative genomic hybridization (aCGH) were used to investigate both phenotypic and genotypic characteristics of different passages of human xenografts and the cell line compared to the tissue of origin. Results: A primary OS cell line and a primary patient-derived orthotopic xenotranplanted mouse model were established. MRI analyses and histopathology demonstrated an identical architecture in the primary tumor and in the xenografts. Array-CGH analyses of the cell line and all xenografts showed highly comparable patterns of genomic progression. So far, three further primary patient-derived orthotopic xenotranplanted mouse models could be established. Conclusion: We report the first orthotopic OS mouse model generated by transplantation of tumor fragments directly harvested from the patient. This model represents the morphologic and genomic identity of the primary tumor and provides a preclinical platform to evaluate new treatment strategies in OS

    Enzymatic activity of glycosyltransferase GLT8D1 promotes human glioblastoma cell migration.

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    peer reviewedGlioblastoma (GBM) is the most aggressive primary brain tumor characterized by infiltrative growth of malignant glioma cells into the surrounding brain parenchyma. In this study, our analysis of GBM patient cohorts revealed a significantly higher expression of Glycosyltransferase 8 domain containing 1 (GLT8D1) compared to normal brain tissue and could be associated with impaired patient survival. Increased in vitro expression of GLT8D1 significantly enhanced migration of two different sphere-forming GBM cell lines. By in silico analysis we predicted the 3D-structure as well as the active site residues of GLT8D1. The introduction of point mutations in the predicted active site reduced its glycosyltransferase activity in vitro and consequently impaired GBM tumor cell migration. Examination of GLT8D1 interaction partners by LC-MS/MS implied proteins associated with cytoskeleton and intracellular transport as potential substrates. In conclusion, we demonstrated that the enzymatic activity of glycosyltransferase GLT8D1 promotes GBM cell migration

    Wirkungen des SGB II auf Personen mit Migrationshintergrund: Projekt IIa1 - 04/06 ; Jahresbericht zum 31.12.2008 - Hauptband

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    Auf Grundlage von Geschäftsdaten, von repräsentativen telefonischen Befragungen und von qualitativen Interviews mit Betroffenen und Fallmanagern wurden die Wirkungen der "Grundsicherung für Arbeitsuchende" auf Migrant/innen untersucht. Ihr Anteil an allen ALG-II Beziehenden beträgt im bundesweiten Durchschnitt 28 Prozent. Im Vergleich zu denjenigen ohne Migrationshintergrund sind sie im Durchschnitt jünger und haben häufiger keinen, aber auch häufiger höhere (Aus-)Bildungsabschlüsse. Die häufig fehlende Anerkennung ausländischer Abschlüsse wirkt sich auf die Arbeitsmarktchancen ebenso negativ aus wie das Fehlen jeglicher Ausbildung. Migrant/innen erhalten bei den Grundsicherungsstellen im Vergleich zu Deutschen ohne Migrationshintergrund mehr Beratungsgespräche, schließen jedoch seltener Eingliederungsvereinbarungen ab und nehmen seltener an Maßnahmen teil. Einige Herkunftsgruppen werden deutlich häufiger mit Sanktionen belegt, andere Herkunftsgruppen deutlich seltener

    Energy Resolution Performance of the CMS Electromagnetic Calorimeter

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    The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals

    Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

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    Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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