842 research outputs found

    Possible background reductions in double beta decay experiments

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    The background induced by radioactive impurities of 208Tl^{208}\rm Tl and 214Bi^{214}\rm Bi in the source of the double beta experiment NEMO-3 has been investigated. New methods of data analysis which decrease the background from the above mentioned contamination are identified. The techniques can also be applied to other double beta decay experiments capable of measuring independently the energies of the two electrons.Comment: 15 pages, 13 figures, accepted in the Nuclear Instruments and Methods

    Saturation physics and angular correlations at RHIC and LHC

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    We investigate the angular correlation between pions and photons produced in deuteron-gold collisions at RHIC and proton-lead collisions at LHC using the Color Glass Condensate formalism and make predictions for the dependence of the production cross section on the angle between the pion and photon at different rapidities and transverse momenta. Measuring this dependence would shed further light on the role of high gluon density and saturation dynamics at RHIC and LHC.Comment: 2-column EPJ C format, requires svjour.cls and svepj.clo; 4 pages, 4 figure

    Heavy-quark energy loss in pQCD and SYM plasmas

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    We consider heavy-quark energy loss and pT-broadening in a strongly-coupled N=4 Super Yang Mills (SYM) plasma, and the problem of finite-extend matter is addressed. When expressed in terms of the appropriate saturation momentum, one finds identical parametric forms for the energy loss in pQCD and SYM theory, while pT-broadening is radiation dominated in SYM theory and multiple scattering dominated in pQCD.Comment: 5 pages, 2 figures, Proceedings of the IIIrd Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions (HotQuarks08), Estes Park, USA, August 18-23 200

    Effects of Crime Type and Location on Park Use Behavior

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    Crime and the fear of crime can be a barrier to park use, and locations of crimes can have varied effects. Unsafe areas in or around the park, around the residence, or along the route to the park can alter park use behavior. Our study aimed to examine associations between objective measures of types and location of crimes and park use behaviors. In 2013 we surveyed a sample (N = 230) of residents in Greensboro, North Carolina, about park use, with responses matched to objective crime and spatial measures. We measured all crimes and violent crimes near home, near the closest park, and along the shortest route between home and park. By using ordered and binary logistic modeling, we examined the relationships between the locations of crime and park use and duration of park visit, park rating, and never visiting parks. Additional models included distance to the closest park. Increased crime in parks and near home was associated with fewer park visits. Greater violent crime in all locations was related to fewer park visits. Park ratings were lower for parks with high violent crime rates. Given the importance of parks as settings for outdoor recreation and physical activity, crime may have a detrimental effect on physical activity and, therefore, public health

    Reduction of peritoneal trauma by using nonsurgical gauze leads to less implantation metastasis of spilled tumor cells

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    OBJECTIVES: To evaluate whether infliction of peritoneal trauma would promote tumor cell adherence to damaged peritoneal surfaces; to investigate whether peritoneal damage could promote tumor growth of extraperitoneal tumors; and to evaluate whether the amount of trauma correlated with the degree of tumor cell adherence and local and distant tumor growth. BACKGROUND DATA: After potentially curative resection of colorectal carcinoma, the most common site for recurrence is locoregional. We previously demonstrated that surgical trauma induces a cascade of events leading to adhesion formation. The same mechanisms may be responsible for improved tumor cell adherence and growth facilitation in early local recurrence. METHODS: A reproducible rat model was used in which peritoneal damage was inflicted by standardized rubbing of the peritoneum with surgical gauzes of different texture. In the first experiment, tumor cell adherence and growth at traumatized and nontraumatized peritoneal sites were assessed semiquantitatively 3 weeks after perioperative intra-abdominal injection of CC-531 tumor cells. In the second experiment, the effect of peritoneal trauma on ectopic tumor growth was investigated (CC-531 implanted under the renal capsule). In the final experiment, we evaluated how soon after peritoneal traumatization tumor cell adhesion and growth-promoting factors were active and whether they could be passively transferred to naive nontraumatized abdominal cavities. RESULTS: A significant correlation between the amount of peritoneal trauma and the degree of tumor take at damaged peritoneal surfaces was found (p < or = 0.018). Tumor take at remote peritoneal sites not directly traumatized was also significantly higher after severe trauma than after moderate trauma of the peritoneum (p < or = 0.005). In addition, a significant correlation between the degree of peritoneal trauma and the growth of ectopic tumors under the renal capsule was observed (p < or = 0.009). The final experiment demonstrated that within a few hours after infliction of peritoneal trauma, tumor growth-promoting effects could be passively transferred to naive recipients. CONCLUSIONS: Surgical trauma is an important factor in the promotion of local recurrence. The enhancing effect of trauma is not restricted to the inflicted site but rather has a generalized character. Avoidance of unnecessary surgical trauma by using gentle techniques and materials is therefore indicated

    The next-to-leading order forward jet vertex in the small-cone approximation

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    We consider within QCD collinear factorization the process p+p to jet + jet +X, where two forward high-pTp_T jets are produced with a large separation in rapidity Δy\Delta y (Mueller-Navelet jets). In this case the (calculable) hard part of the reaction receives large higher-order corrections αsn(Δy)n\sim \alpha^n_s (\Delta y)^n, which can be accounted for in the BFKL approach. In particular, we calculate in the next-to-leading order the impact factor (vertex) for the production of a forward high-pTp_T jet, in the approximation of small aperture of the jet cone in the pseudorapidity-azimuthal angle plane. The final expression for the vertex turns out to be simple and easy to implement in numerical calculations.Comment: 32 pages, 4 figures; a few comments and one reference added; a few inessential misprints removed; version to appear on JHE

    Scavenging of reactive oxygen species leads to diminished peritoneal tumor recurrence

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    Previously, we demonstrated that RBCs inhibit the recurrence of perioperatively spilled tumor cells. The aim of this study was to identify on which RBC component(s) the inhibitory effect is based. By using a cell-seeding model in rats, the effect of RBC-related antioxidant scavengers [hemoglobin, catalase, and superoxide dismutase (SOD)] on peritoneal tumor recurrence was investigated. i.p. injection of hemoglobin caused 45% more tumor load (P < 0.0001). At least 40% inhibition of tumor recurrence was achieved with the use of catalase or SOD (P < 0.05). Combining SOD and catalase did not lead to additional inhibition of tumor recurrence. Inhibition of the overwhelmin

    Technical design and performance of the NEMO3 detector

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    The development of the NEMO3 detector, which is now running in the Frejus Underground Laboratory (L.S.M. Laboratoire Souterrain de Modane), was begun more than ten years ago. The NEMO3 detector uses a tracking-calorimeter technique in order to investigate double beta decay processes for several isotopes. The technical description of the detector is followed by the presentation of its performance.Comment: Preprint submitted to Nucl. Instrum. Methods A Corresponding author: Corinne Augier ([email protected]
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