667 research outputs found

    Design and implementation of synchrotron radiation masks for LEP2

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    Estimates of photon flux for LEP2 have predicted unacceptable background levels within the detectors of the four LEP experiments. As part of the solution to this problem, synchrotron radiation masks have been installed within the experimental vacuum Chambers close to the interaction points. The photon flux calculations and specification for the masks have been laid-out by von Holtey et.al. [1]. This paper describes the design of the masks and outlines the principal technical issues overcome for their installation and alignment

    Is Individually-Targeted Food Assistance Shared among Family Members?

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    The Supplemental Nutrition Assistance Program (SNAP), the National School Lunch Program (NSLP), the School Breakfast Program (SBP), and the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) share a common goal of helping people with limited financial means obtain better diets than they could otherwise afford, but the programs differ in terms of the groups that they target and the types of assistance they provide. While the pro-grams appear to increase food consumption among households generally and among their intended beneficiaries, we know much less about whether they help other people. This investigation uses 2002-2003 data from the second Child Development Supplement of the Panel Study of Income Dynamics to examine the relationship between households’ participation in the SNAP, SBP, NLSP, and WIC and individual 10 - 17 year-old children’s consumption of particular food items. Our analyses indicate that WIC participation by others in the household is associated with a 22 percent in-crease in breakfast consumption of milk and a 16 percent increase in breakfast consumption of cereal for the children in our sample, while WIC is associated with a 13 percent decrease in toast consumption. Participation in school meals is also associated with increased consumption of some foods, particularly juice, fruit, and sweet snacks. Household SNAP participation is estimated to have positive associations with some foods but negative associations with others

    Beam Vacuum Interconnects for the LHC Cold Arcs

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    The design of the beam vacuum interconnect is described in this paper. Features include a novel RF bridge design to maximise lateral flexibility during cryostat Cold arcs of the LHC will consist of twin aperture dipole, quadrupole and corrector magnets in cryostats, operating at 1.9 K. Beam vacuum chambers, along with all connecting elements require flexible 'interconnects' between adjacent cryostats to allow for thermal and mechanical offsets foreseen during machine operation and alignment. In addition, the beam vacuum chambers contain perforated beam screens to intercept beam induced heat loads at an intermediate temperature. These must also be connected with low impedance RF bridges in the interconnect zones.alignment and so-called 'nested' bellows to minimise the required length of the assembly

    Incidence of severe retinopathy of prematurity before and after a modest reduction in target oxygen saturation levels

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    Previous studies suggest that reducing target oxygen saturation levels to 85–93% decreases the incidence of severe retinopathy of prematurity (ROP). Our aim was to determine if a more modest reduction in target oxygen saturation levels also reduces ROP incidence

    Merkel-cell carcinoma: ESMO-EURACAN Clinical Practice Guideline for diagnosis, treatment and follow-up

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    : • This ESMO Clinical Practice Guideline provides key recommendations for managing Merkel-cell carcinoma (MCC). • Recommendations are based on available scientific data and the multidisciplinary group of experts’ collective opinion. • The guideline covers clinical and pathological diagnosis, staging and risk assessment, treatment and follow-up. • Algorithms for the management of locoregional and inoperable/metastatic disease are provided. • A multidisciplinary team with a high level of expertise in MCC should diagnose and make decisions about therapy

    Mechanical Design Aspects of The LHC Beam screen

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    Forty-four kilometers of the LHC beam vacuum system [1,2] will be equipped with a perforated co-axial liner, the so-called beam screen. Operating between 5 K and 20 K, the beam screen reduces heat loads to the 1.9 K helium bath of the superconducting magnets and minimises dynamic vacuum effects. Constructed from low magnetic permeability stainless steel with a 50 mm inner layer of high purity copper, the beam screen must provide a maximum aperture for the beam whilst resisting the induced forces due to eddy currents at magnet quench. The mechanical engineering challenges are numerous, and include stringent requirements on geometry, material selection, manufacturing techniques and cleanliness. The industrial fabrication of these 16 metre long UHV components is now in its prototyping phase. A description of the beam screen is given, together with details of the experimental programme aimed at validating the design choices, and results of the first industrial prototypes

    Postoperative Concurrent Chemoradiotherapy Versus Postoperative Radiotherapy in High-Risk Cutaneous Squamous Cell Carcinoma of the Head and Neck: The Randomized Phase III TROG 05.01 Trial

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    © 2018 by American Society of Clinical Oncology Purpose To report the results of the Trans Tasman Radiation Oncology Group randomized phase III trial designed to determine whether the addition of concurrent chemotherapy to postoperative radiotherapy (CRT) improved locoregional control in patients with high-risk cutaneous squamous cell carcinoma of the head and neck. Patients and Methods The primary objective was to determine whether there was a difference in freedom from locoregional relapse (FFLRR) between 60 or 66 Gy (6 to 6.5 weeks) with or without weekly carboplatin (area under the curve 2) after resection of gross disease. Secondary efficacy objectives were to compare disease-free survival and overall survival. Results Three hundred twenty-one patients were randomly assigned, with 310 patients commencing allocated treatment (radiotherapy [RT] alone, n = 157; CRT, n = 153). Two hundred thirty-eight patients (77%) had high-risk nodal disease, 59 (19%) had high-risk primary or in-transit disease, and 13 (4%) had both. Median follow-up was 60 months. Median RT dose was 60 Gy, with 84% of patients randomly assigned to CRT completing six cycles of carboplatin. The 2- and 5-year FFLRR rates were 88% (95% CI, 83% to 93%) and 83% (95% CI, 77% to 90%), respectively, for RT and 89% (95% CI, 84% to 94%) and 87% (95% CI, 81% to 93%; hazard ratio, 0.84; 95% CI, 0.46 to 1.55; P = .58), respectively, for CRT. There were no significant differences in disease-free or overall survival. Locoregional failure was the most common site of first treatment failure, with isolated distant metastases as the first site of failure seen in 7% of both arms. Treatment was well tolerated in both arms, with no observed enhancement of RT toxicity with carboplatin. Grade 3 or 4 late toxicities were infrequent. Conclusion Although surgery and postoperative RT provided excellent FFLRR, there was no observed benefit with the addition of weekly carboplatin
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