190 research outputs found

    Aerodynamic characteristics of rotating wind-driven airfoils

    Get PDF
    Thesis (B.S.)-- Massachusetts Institute of Technology, Dept. of General Engineering, 1925.by John L. Hosch, Horace E. Weihmiller.B.S

    Dimension-six CP-conserving operators of the third-family quarks and their effects on collider observables

    Get PDF
    We list all possible dimension-six CP-conserving SUc(3)×SUL(2)×UY(1)SU_c(3)\times SU_L(2) \times U_Y(1) invariant operators involving the third-family quarks which could be generated by new physics at a higher scale. Expressions for these operators after electroweak gauge symmetry breaking and the induced effective couplings WtbˉWt\bar b, XbbˉXb\bar b and XttˉXt\bar t (X=Z,γ,g,H)( X=Z,\gamma,g,H) are presented. Analytic expressions for the tree level contributions of all these operators to the observables RbR_b and AFBbA^b_{FB} at LEP I, σ(e+ebbˉ)\sigma(e^+e^-\rightarrow b\bar b) and AFBbA^b_{FB} at LEP II, σ(e+ettˉ)\sigma(e^+e^-\rightarrow t\bar t) and AFBtA_{FB}^t at the NLC, as well as σ(ppˉtbˉ+X)\sigma(p\bar p\rightarrow t\bar b+X) at the Tevatron upgrade, are provided. The effects of these operators on different electroweak observables are discussed and numerical examples presented. Numerical analyses show that in the coupling region allowed by RbR_b and AFBbA^b_{FB} at LEP I, some of the new physics operators can still have significant contributions at LEP II, the Tevatron and the NLC.Comment: 25 page

    Probing Topcolor-Assisted Technicolor from Top-Charm Associated Production at LHC

    Get PDF
    We propose to probe the topcolor-assisted technicolor (TC2) model from the top-charm associated productions at the LHC, which are highly suppressed in the Standard Model. Due to the flavor-changing couplings of the top quark with the scalars (top-pions and top-Higgs) in TC2 model, the top-charm associated productions can occur via both the s-channel and t-channel parton processes by exchanging a scalar field at the LHC. We examined these processes through Monte Carlo simulation and found that they can reach the observable level at the LHC in quite a large part of the parameter space of the TC2 model.Comment: Version to appear in PRD (Rapid Communication

    Single Top Quark Production via FCNC Couplings at Hadron Colliders

    Get PDF
    We calculate single top-quark production at hadron colliders via the chromo-magnetic flavor-changing neutral current couplings tˉcg\bar tcg and tˉug\bar tug. We find that the strength for the anomalous tˉcg\bar tcg (tˉug\bar tug) coupling may be probed to κc/Λ=0.092TeV1\kappa_c / \Lambda = 0.092 {TeV}^{-1} (κu/Λ=0.026TeV1\kappa_u / \Lambda = 0.026 {TeV}^{-1}) at the Tevatron with 2fb12 {fb}^{-1} of data and κc/Λ=0.013TeV1\kappa_c / \Lambda = 0.013 {TeV}^{-1} (κu/Λ=0.0061TeV1\kappa_u / \Lambda = 0.0061 {TeV}^{-1}) at the LHC with 10fb110 {fb}^{-1} of data. The two couplings may be distinguished by a comparision of the single top signal with the direct top and top decay signals for these couplings.Comment: 18 pages, 6 figures, 3 table

    Homologous and heterologous desensitization of guanylyl cyclase-B signaling in GH3 somatolactotropes

    Get PDF
    The guanylyl cyclases, GC-A and GC-B, are selective receptors for atrial and C-type natriuretic peptides (ANP and CNP, respectively). In the anterior pituitary, CNP and GC-B are major regulators of cGMP production in gonadotropes and yet mouse models of disrupted CNP and GC-B indicate a potential role in growth hormone secretion. In the current study, we investigate the molecular and pharmacological properties of the CNP/GC-B system in somatotrope lineage cells. Primary rat pituitary and GH3 somatolactotropes expressed functional GC-A and GC-B receptors that had similar EC50 properties in terms of cGMP production. Interestingly, GC-B signaling underwent rapid homologous desensitization in a protein phosphatase 2A (PP2A)-dependent manner. Chronic exposure to either CNP or ANP caused a significant down-regulation of both GC-A- and GC-B-dependent cGMP accumulation in a ligand-specific manner. However, this down-regulation was not accompanied by alterations in the sub-cellular localization of these receptors. Heterologous desensitization of GC-B signaling occurred in GH3 cells following exposure to either sphingosine-1-phosphate or thyrotrophin-releasing hormone (TRH). This heterologous desensitization was protein kinase C (PKC)-dependent, as pre-treatment with GF109203X prevented the effect of TRH on CNP/GC-B signaling. Collectively, these data indicate common and distinct properties of particulate guanylyl cyclase receptors in somatotropes and reveal that independent mechanisms of homologous and heterologous desensitization occur involving either PP2A or PKC. Guanylyl cyclase receptors thus represent potential novel therapeutic targets for treating growth-hormone-associated disorders

    Ep-CAM expression in squamous cell carcinoma of the esophagus: a potential therapeutic target and prognostic marker

    Get PDF
    BACKGROUND: To evaluate the expression and test the clinical significance of the epithelial cellular adhesion molecule (Ep-CAM) in esophageal squamous cell carcinoma (SCC) to check the suitability of esophageal SCC patients for Ep-CAM directed targeted therapies. METHODS: The Ep-CAM expression was immunohistochemically investigated in 70 primary esophageal SCCs using the monoclonal antibody Ber-EP4. For the interpretation of the staining results, we used a standardized scoring system ranging from 0 to 3+. The survival analysis was calculated from 53 patients without distant metastasis, with R0 resection and at least 2 months of clinical follow-up. RESULTS: Ep-CAM neo-expression was observed in 79% of the tumors with three expression levels, 1+ (26%), 2+ (11%) and 3+ (41%). Heterogeneous expression was observed at all expression levels. Interestingly, tumors with 3+ Ep-CAM expression conferred a significantly decreased median relapse-free survival period (log rank, p = 0.0001) and median overall survival (log rank, p = 0.0003). Multivariate survival analysis disclosed Ep-CAM 3+ expression as independent prognostic factor. CONCLUSION: Our results suggest Ep-CAM as an attractive molecule for targeted therapy in esophageal SCC. Considering the discontenting results of the current adjuvant concepts for esophageal SCC patients, Ep-CAM might provide a promising target for an adjuvant immunotherapeutic intervention

    First International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions).

    Get PDF
    The purpose of this study is to obtain a consensus for the therapy of B3 lesions. The first International Consensus Conference on lesions of uncertain malignant potential in the breast (B3 lesions) including atypical ductal hyperplasia (ADH), flat epithelial atypia (FEA), classical lobular neoplasia (LN), papillary lesions (PL), benign phyllodes tumors (PT), and radial scars (RS) took place in January 2016 in Zurich, Switzerland organized by the International Breast Ultrasound School and the Swiss Minimally Invasive Breast Biopsy group-a subgroup of the Swiss Society of Senology. Consensus recommendations for the management and follow-up surveillance of these B3 lesions were developed and areas of research priorities were identified. The consensus recommendation for FEA, LN, PL, and RS diagnosed on core needle biopsy or vacuum-assisted biopsy (VAB) is to therapeutically excise the lesion seen on imaging by VAB and no longer by open surgery, with follow-up surveillance imaging for 5 years. The consensus recommendation for ADH and PT is, with some exceptions, therapeutic first-line open surgical excision. Minimally invasive management of selected B3 lesions with therapeutic VAB is acceptable as an alternative to first-line surgical excision

    Stop and Sbottom Searches in Run II of the Fermilab Tevatron

    Get PDF
    We estimate the Tevatron Run II potential for top and bottom squark searches. We find an impressive reach in several of the possible discovery channels. We also study some new channels which may arise in non-conventional supersymmetry models. In each case we rely on a detailed Monte Carlo simulation of the collider events and the CDF detector performance in Run I.Comment: 30 pages, LaTeX, 10 figure

    Single top production at the LHC as a probe of R parity violation

    Full text link
    We investigate the potential of the LHC to probe the R parity violating couplings involving the third generation by considering single top production. This study is based on particle level event generation for both signal and background, interfaced to a simplified simulation of the ATLAS detector.Comment: 11 pages, 5 figures, 5 tables (LaTeX, style revtex), few references adde

    Cystic Echinococcosis: Chronic, Complex, and Still Neglected

    Get PDF
    Cystic echinococcosis is a most clinically neglected parasitic disease that urgently needs attention. A valuable tool for diagnosing, staging, and following up patients, ultrasound, is readily available. Four management procedures, surgery, percutaneous sterilization techniques, anti-parasitic treatment, and watch & wait, have ‘‘evolved’’ over decades, and been recently summarized, but without adequate comparative evaluation of efficacy, effectiveness, rate of adverse events, relapse rates, and cost. Clinical decision making is on even shakier ground for extrahepatic and extrapulmonary locations, which are rarer and numbers needed to build comparative trials hard to come by. There is an obligation to put at least what we have on an appropriate evidence base by conducting comparative clinical trials at the scale and quality that allow answering these important questions. As one of the expected results, clear criteria for the watch & wait option alone might already save a substantial proportion of patients from unnecessary interventions and save health services money. Difficult chronic diseases clustering in poor rural areas need intelligent, creative approaches, and this one urgently needs operational research incorporating the particularities of resource- poor settings into consideration
    corecore