628 research outputs found

    Electromechanical Reliability Testing of Three-Axial Silicon Force Sensors

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    This paper reports on the systematic electromechanical characterization of a new three-axial force sensor used in dimensional metrology of micro components. The siliconbased sensor system consists of piezoresistive mechanicalstress transducers integrated in thin membrane hinges supporting a suspended flexible cross structure. The mechanical behavior of the fragile micromechanical structure isanalyzed for both static and dynamic load cases. This work demonstrates that the silicon microstructure withstands static forces of 1.16N applied orthogonally to the front-side of the structure. A statistical Weibull analysis of the measured data shows that these values are significantly reduced if the normal force is applied to the back of the sensor. Improvements of the sensor system design for future development cycles are derived from the measurement results.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

    Testing the Mechanism for the LSP Stability at the LHC

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    The lightest supersymmetric particle (LSP) is a natural candidate for the cold dark matter of the universe. In this Letter we discuss how to test the mechanism responsible for the LSP stability at the LHC. We note that if R-parity is conserved dynamically one should expect a Higgs boson which decays mainly into two right-handed neutrinos (a "leptonic" Higgs) or into two sfermions. The first case could exhibit spectacular lepton number violating signals with four secondary vertices due to the long-lived nature of right-handed neutrinos. These signals, together with the standard channels for the discovery of SUSY, could help to establish the underlying theory at the TeV scale.Comment: 4 pages, 3 figures, 1 table, minor corrections, published in Physics Letters

    The physical determinants of the thickness of lamellar polymer crystals

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    Based upon kinetic Monte Carlo simulations of crystallization in a simple polymer model we present a new picture of the mechanism by which the thickness of lamellar polymer crystals is constrained to a value close to the minimum thermodynamically stable thickness. This description contrasts with those given by the two dominant theoretical approaches.Comment: 4 pages, 4 figures, revte

    When Anomaly Mediation is UV Sensitive

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    Despite its successes---such as solving the supersymmetric flavor problem---anomaly mediated supersymmetry breaking is untenable because of its prediction of tachyonic sleptons. An appealing solution to this problem was proposed by Pomarol and Rattazzi where a threshold controlled by a light field deflects the anomaly mediated supersymmetry breaking trajectory, thus evading tachyonic sleptons. In this paper we examine an alternate class of deflection models where the non-supersymmetric threshold is accompanied by a heavy, instead of light, singlet. The low energy form of this model is the so-called extended anomaly mediation proposed by Nelson and Weiner, but with potential for a much higher deflection threshold. The existence of this high deflection threshold implies that the space of anomaly mediated supersymmetry breaking deflecting models is larger than previously thought.Comment: 14 pages, 1 figure (version to appear in JHEP

    Increasing HPV Vaccination in a Network of Pediatric Clinics using a Multi-component Approach

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    Background: Despite continued public health efforts to increase human papillomavirus (HPV) vaccination among adolescents, initiation remains below the level needed to reach the Healthy People 2020 goal of 80% series completion by age 13. Methods: We developed, implemented, and evaluated a multi-component program that used evidence-based strategies to increase HPV vaccine initiation in a network of 51 pediatric clinics in Houston, Texas. Our target populations were the clinic network, healthcare providers, male and female patients ages 11-17, and their parents. The program, called the Adolescent Vaccination Program (AVP), was conducted from March 2016 through March 2019 and contained strategies to increase vaccination including: HPV immunization champions; provider assessment and feedback; provider continuing education; provider reminders; and patient reminders. We used a single group pre/post design with an external comparison – NIS-Teen. Our primary outcome was initiation of the HPV vaccine based on the electronic health record. We used interrupted time series analysis (ITSA) to measure change in initiation over time. We calculated monthly, quarterly, and annual rates of initiation for each physician, clinic, and the network. We examined patterns of initiation by patient age, sex, race/ethnicity, and type of insurance. Results: By the end of the project, the 51 clinics averaged 77.4% initiation. Rates increased annually from September 2015 through March 2019. ITSA analysis over 75 months showed an increase in vaccine initiation of 0.396% per month from the introduction of the program in March 2016. Average individual clinic improvement was 0.37% per month ranging from -0.04% to 0.68% through March 2019. Data for the 11-12 year olds, the target age group for initiating the vaccine, showed a greater percentage increase (54.2%) compared with the 13-17 year olds (29.6%). Hispanics and African Americans had the highest initiation rates in all years while non-Hispanic whites had the lowest. Families without insurance had the lowest rates while those with Medicaid/Medicare had the highest. Conclusions: We observed a secular trend upward in both the network and NIS-Teen data; however, the network showed a steeper increase. The AVP is a promising program of strategies to increase HPV vaccination in a clinic setting

    Presence and Persistence of Ebola or Marburg Virus in Patients and Survivors: A Rapid Systematic Review

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    Background: The 2013-15 Ebola outbreak was unprecedented due to sustainedtransmission within urban environments and thousands of survivors. In 2014 the World Health Organization stated that there was insufficient evidence to give definitive guidance about which body fluids are infectious and when they pose a risk to humans. We report a rapid systematic review of published evidence on the presence of filoviruses in body fluids of infected people and survivors. Methods: Scientific articles were screened for information about filovirus in human body fluids. The aim was to find primary data that suggested high likelihood of actively infectious filovirus in human body fluids (viral RNA). Eligible infections were from Marburg virus (MARV or RAVV) and Zaire, Sudan, Taï Forest and Bundibugyo species of Ebola. [1] Cause of infection had to be laboratory confirmed (in practice either tissue culture or RT-PCR tests), or evidenced by compatible clinical history with subsequent positivity for filovirus antibodies or inflammatory factors. Data were extracted and summarized narratively. Results: 6831 unique articles were found, and after screening, 33 studies were eligible. For most body fluid types there were insufficient patients to draw strong conclusions, and prevalence of positivity was highly variable. Body fluids taken >16 days after onset were usually negative. In the six studies that used both assay methods RT-PCR tests for filovirus RNA gave positive results about 4 times more often than tissue culture. Conclusions: Filovirus was reported in most types of body fluid, but not in every sample from every otherwise confirmed patient. Apart from semen, most non-blood, RT-PCR positive samples are likely to be culture negative and so possibly of low infectious risk. Nevertheless, it is not apparent how relatively infectious many body fluids are during or after illness, even when culture-positive, not least because most test results come from more severe cases. Contact with blood and blood-stained body fluids remains the major risk for disease transmission because of the known high viral loads in blood
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