21 resultados para Direct digital detector

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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The aim of this study was to simulate direct-digital cephalometric procedures and to record the head movements of probands. This study was prompted by the Committee for Insurance Matters of the Swiss National Invalidity Insurance which does not accept scanned digital cephalometric radiographs as a basis for its decisions. The reason for this is the required scanning time of several seconds during which even slight head movements can lead to kinetic blurring and landmark displacement. Incorrect angular measurements may result. By means of a Sirognathograph and a cephalostat of non-ferromagnetic material, the head movements of a total of 264 subjects were recorded in three dimensions, with a scanning time of up to 25 seconds. In a second series, the influence of a chin support to reduce head movements was also tested. The results of the first series of tests showed that, with an increasing scan time, movements became greater, mostly in the sagittal plane, and that maximum displacements could occur already at the start of the recording. With a scan time of 10 seconds the median movement amplitude in the vertical dimension was 2.14 mm. The second series of tests revealed a significant reduction in head movements in all dimensions owing to an additional stabilizing chin support. To minimize head movements, scanning times must be reduced and additional head stabilizing elements together with existing ones are necessary.

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A search for direct chargino production in anomaly-mediated supersymmetry breaking scenarios is performed in p p collisions at root s = 7 TeV using 4.7 fb(-1) of data collected with the ATLAS experiment at the LHC. In these models, the lightest chargino is predicted to have a lifetime long enough to be detected in the tracking detectors of collider experiments. This analysis explores such models by searching for chargino decays that result in tracks with few associated hits in the outer region of the tracking system. The transverse-momentum spectrum of candidate tracks is found to be consistent with the expectation from the Standard Model background processes and constraints on chargino properties are obtained.

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A search for the electroweak pair production of charged sleptons and weak gauginos decaying into final states with two leptons is performed using 4.7 fb(-1) of proton-proton collision data at root s = 7 TeV recorded with the ATLAS experiment at the Large Hadron Collider. No significant excesses are observed with respect to the prediction from Standard Model processes. In the scenario of direct slepton production, if the sleptons decay directly into the lightest neutralino, left-handed slepton masses between 85 and 195 GeV are excluded at 95% confidence level for a 20 GeV neutralino. Chargino masses between 110 and 340 GeV are excluded in the scenario of direct production of wino-like chargino pairs decaying into the lightest neutralino via an intermediate on-shell charged slepton for a 10 GeV neutralino. The results are also interpreted in the framework of the phenomenological minimal supersymmetric Standard Model.

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The results of a search for pair production of supersymmetric partners of the Standard Model third-generation quarks are reported. This search uses 20.1 fb(-1) of pp collisions at root s = 8 TeV collected by the ATLAS experiment at the Large Hadron Collider. The lightest bottom and top squarks ((b) over tilde (1) and (t) over tilde (1) respectively) are searched for in a final state with large missing transverse momentum and two jets identified as originating from b-quarks. No excess of events above the expected level of Standard Model background is found. The results are used to set upper limits on the visible cross section for processes beyond the Standard Model. Exclusion limits at the 95% confidence level on the masses of the third-generation squarks are derived in phenomenological supersymmetric R-parity-conserving models in which either the bottom or the top squark is the lightest squark. The (b) over tilde (1) is assumed to decay via (b) over tilde (1) -> b (chi) over tilde (0)(1) and the (t) over tilde (1) via (t) over tilde (1) b (chi) over tilde (+/-)(1), with undetectable products of the subsequent decay of the (chi) over tilde (+/-)(1) due to the small mass splitting between the (chi) over tilde (+/-)(1) and the (chi) over tilde (0)(1)

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The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton-proton collision data at s√=8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t~→tχ~01 or t~→bχ~±1→bW(∗)χ~01, where χ~01 (χ~±1) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t~→tχ~01. For a branching fraction of 100%, top squark masses in the range 270-645 GeV are excluded for χ~01 masses below 30 GeV. For a branching fraction of 50% to either t~→tχ~01 or t~→bχ~±1, and assuming the χ~±1 mass to be twice the χ~01 mass, top squark masses in the range 250-550 GeV are excluded for χ~01 masses below 60 GeV.

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Searches for the electroweak production of charginos, neutralinos and sleptons in final states characterized by the presence of two leptons (electrons and muons) and missing transverse momentum are performed using 20.3 fb−1 of proton-proton collision data at ps = 8TeV recorded with the ATLAS experiment at the Large Hadron Collider. No significant excess beyond Standard Model expectations is observed. Limits are set on the masses of the lightest chargino, next-to-lightest neutralino and sleptons for different lightest-neutralino mass hypotheses in simplified models. Results are also interpreted in various scenarios of the phenomenological Minimal Supersymmetric Standard Model.

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A search is presented for direct top squark pair production using events with at least two leptons including a same-flavour opposite-sign pair with invariant mass consistent with the Z boson mass, jets tagged as originating from b-quarks and missing transverse momentum. The analysis is performed with proton–proton collision data at √ s = 8 TeV collected with the ATLAS detector at the LHC in 2012 corresponding to an integrated luminosity of 20.3 fb−1. No excess beyond the Standard Model expectation is observed. Interpretations of the results are provided in models based on the direct pair production of the heavier top squark state (˜t2) followed by the decay to the lighter top squark state (˜t1) via ˜t2 → Z ˜t1, and for ˜t1 pair production in natural gaugemediated supersymmetry breaking scenarios where the neutralino (˜χ 01 ) is the next-to-lightest supersymmetric particle and decays producing a Z boson and a gravitino ( ˜G ) via the ˜χ 01→ Z ˜G process.

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A search is presented for direct top-squark pair production in final states with two leptons (electrons or muons) of opposite charge using 20.3 fb−1 of pp collision data at ps = 8TeV, collected by the ATLAS experiment at the Large Hadron Collider in 2012. No excess over the Standard Model expectation is found. The results are interpreted under the separate assumptions (i) that the top squark decays to a b-quark in addition to an on-shell chargino whose decay occurs via a real or virtual W boson, or (ii) that the top squark decays to a t-quark and the lightest neutralino. A top squark with a mass between 150 GeV and 445 GeV decaying to a b-quark and an on-shell chargino is excluded at 95% confidence level for a top squark mass equal to the chargino mass plus 10 GeV, in the case of a 1 GeV lightest neutralino. Top squarks with masses between 215 (90) GeV and 530 (170) GeV decaying to an on-shell (off-shell) t-quark and a neutralino are excluded at 95% confidence level for a 1 GeV neutralino.

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A search for the direct production of charginos and neutralinos in final states with three leptons and missing transverse momentum is presented. The analysis is based on 20.3 fb−1 of √s = 8TeV proton-proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with the Standard Model expectations and limits are set in R-parity-conserving phenomenological Minimal Supersymmetric Standard Models and in simplified supersymmetric models, significantly extending previous results. For simplified supersymmetric models of direct chargino (˜χ±1 ) and next-to-lightest neutralino (˜χ02) production with decays to lightest neutralino(˜χ01) via either all three generations of sleptons, staus only, gauge bosons, or Higgs bosons, ˜χ±1 and ˜χ02 masses are excluded up to 700GeV, 380GeV, 345GeV, or 148GeV respectively, for a massless ˜χ01.

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The effect of copper (Cu) filtration on image quality and dose in different digital X-ray systems was investigated. Two computed radiography systems and one digital radiography detector were used. Three different polymethylmethacrylate blocks simulated the pediatric body. The effect of Cu filters of 0.1, 0.2, and 0.3 mm thickness on the entrance surface dose (ESD) and the corresponding effective doses (EDs) were measured at tube voltages of 60, 66, and 73 kV. Image quality was evaluated in a contrast-detail phantom with an automated analyzer software. Cu filters of 0.1, 0.2, and 0.3 mm thickness decreased the ESD by 25-32%, 32-39%, and 40-44%, respectively, the ranges depending on the respective tube voltages. There was no consistent decline in image quality due to increasing Cu filtration. The estimated ED of anterior-posterior (AP) chest projections was reduced by up to 23%. No relevant reduction in the ED was noted in AP radiographs of the abdomen and pelvis or in posterior-anterior radiographs of the chest. Cu filtration reduces the ESD, but generally does not reduce the effective dose. Cu filters can help protect radiosensitive superficial organs, such as the mammary glands in AP chest projections.

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The aim of this study was to describe the tenovaginoscopic approach to the bovine common digital flexor tendon sheath (CDFTS). A comparative anatomical, ultrasonographic and endoscopic study was undertaken using 26 healthy cadaver feet from adult dairy cows. Tenovaginoscopy was performed using a rigid, 30 degrees arthroscope (length 18 cm; outer diameter 4mm) enabling a direct view of the synovial cavity and the following structures: digital flexor tendons, digital annular ligaments, lateral and medial pouches, three mesotendons, the vinculum of the superficial digital flexor tendon, and a slot-shaped opening in the manicaflexoria of the hind feet. Additionally, four clinical cases of septic tenosynovitis treated with lavage under tenovaginoscopic control were examined. Tenovaginoscopy represents a feasible, minimally invasive method for the diagnosis and treatment of septic tenosynovitis of the CDFTS, which allows the degree of alterations of the normal structures to be evaluated.

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The purpose of the study was to evaluate observer performance in the detection of pneumothorax with cesium iodide and amorphous silicon flat-panel detector radiography (CsI/a-Si FDR) presented as 1K and 3K soft-copy images. Forty patients with and 40 patients without pneumothorax diagnosed on previous and subsequent digital storage phosphor radiography (SPR, gold standard) had follow-up chest radiographs with CsI/a-Si FDR. Four observers confirmed or excluded the diagnosis of pneumothorax according to a five-point scale first on the 1K soft-copy image and then with help of 3K zoom function (1K monitor). Receiver operating characteristic (ROC) analysis was performed for each modality (1K and 3K). The area under the curve (AUC) values for each observer were 0.7815, 0.7779, 0.7946 and 0.7066 with 1K-matrix soft copies and 0.8123, 0.7997, 0.8078 and 0.7522 with 3K zoom. Overall detection of pneumothorax was better with 3K zoom. Differences between the two display methods were not statistically significant in 3 of 4 observers (p-values between 0.13 and 0.44; observer 4: p = 0.02). The detection of pneumothorax with 3K zoom is better than with 1K soft copy but not at a statistically significant level. Differences between both display methods may be subtle. Still, our results indicate that 3K zoom should be employed in clinical practice.

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Background: Monitoring alcohol use is important in numerous situations. Direct ethanol metabolites, such as ethyl glucuronide (EtG), have been shown to be useful tools in detecting alcohol use and documenting abstinence. For very frequent or continuous control of abstinence, they lack practicability. Therefore, devices measuring ethanol itself might be of interest. This pilot study aims at elucidating the usability and accuracy of the cellular photo digital breathalyzer (CPDB) compared to self-reports in a naturalistic setting. Method: 12 social drinkers were included. Subjects used a CPDB 4 times daily, kept diaries of alcohol use and submitted urine for EtG testing over a period of 5 weeks. Results: In total, the 12 subjects reported 84 drinking episodes. 1,609 breath tests were performed and 55 urine EtG tests were collected. Of 84 drinking episodes, CPDB detected 98.8%. The compliance rate for breath testing was 96%. Of the 55 EtG tests submitted, 1 (1.8%) was positive. Conclusions: The data suggest that the CPDB device holds promise in detecting high, moderate, and low alcohol intake. It seems to have advantages compared to biomarkers and other Monitoring devices. The preference for CPDB by the participants might explain the high compliance. Further studies including comparison with biomarkers and transdermal devices are needed.

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Shaped by factors like global outreach and immediacy, particularly the internet represents the multi-layered nature of contemporary globalization (cf Held et al. 2002). How have digital newspapers, social media and other internet platforms altered the situation of smaller music microcultues, especially in regions that have been on the fringes of global networks? This paper analyses the situation of the Latvian postfolklore band Ilgi between 2001 and 2008. Focusing on the group’s label UPE, the paper highlights how the internet became a significant means of existence during this specific period. Having established a local niche with a sound studio and CD shops, UPE combined this physical basis with outreach strategies, such as marketing and direct internet sales, which guaranteed the survival of the independent label. This strategy was also taken up by the band itself who started to develop a strong presence on social media like MySpace. At the same time, Ilgi has been using the internet as a central means of communicating with diasporic communities in the U.S. and Canada – hereby creating structures that were described as « intercultures » by Slobin (1993). This indicates that the local-global dichotomy can no longer be sufficiently addressed by a horizontal or vertical two-dimensional perception. Falling also back on the fieldwork experiences gained in Latvia, the paper finally addresses the question of how internet representation relates to the actual local situation – and how this has been altering the fieldwork perception. With regard to this situation – how useful are the approaches that have been developed within the context of « Media Anthropology » that investigates mass media items as multi-layered, densified symbolic objects?