Advanced alignment of the ATLAS tracking system Pedraza-Lopez, Sebastian
2012 IEEE Nuclear Science Symposium and Medical Imaging Conference Record (NSS/MIC),
2012-Oct.
Conference Proceeding
Odprti dostop
In order to reconstruct trajectories of charged particles, ATLAS is equipped with a tracking system built using different technologies embedded in a 2T solenoidal magnetic field. ATLAS physics goals ...require high resolution and unbiased measurement of all charged particle kinematic parameters. These critically depend on the systematic effects related to the alignment of the tracking system. In order to eliminate malicious systematic deformations, various advanced tools and techniques have been put in place. These include information from known mass resonances, energy of electrons and positrons measured by the electromagnetic calorimeters, etc. Despite being stable under normal running conditions, ATLAS tracking system responses to sudden environmental changes (temperature, magnetic field) by small collective deformations. These have to be identified and corrected in order to assure uniform, highest quality tracking performance throughout the whole data taking. We will present an outline of the track based alignment approaches and special attention will be paid to techniques allowing to identify and eliminate tracking systematics.
The current management of acute diverticulitis of the left colon (ADLC) requires tests with high prognostic value. This paper analyzes the usefulness of ultrasonography (US) in the initial diagnosis ...of ADLC and the validity of current classifications schemes for ADLC.
This retrospective observational study included patients with ADLC scheduled to undergo US or computed tomography (CT) following a clinical algorithm. According to the imaging findings, ADLC was classified as mild, locally complicated, or complicated. We analyzed the efficacy of US in the initial diagnosis and the reasons why CT was used as the first-line technique. We compared the findings with published classifications schemes for ADLC.
A total of 311 patients were diagnosed with acute diverticulitis; 183 had ADLC, classified at imaging as mild in 104, locally complicated in 60, and complicated in 19. The diagnosis was reached by US alone in 98 patients, by CT alone in 77, and by combined US and CT in 8. The main reasons for using CT as the first-line technique were the radiologist’s lack of experience in abdominal US and the unavailability of a radiologists on call. Six patients diagnosed by US were reexamined by CT, but the classification changed in only three. None of the published classification schemes included all the imaging findings.
US should be the first-line imaging technique in patients with suspected ADLC. Various laboratory and imaging findings are useful in establishing the prognosis of ADLC. New schemes to classify the severity of ADLC are necessary to ensure optimal clinical decision making.
El manejo actual de la diverticulitis aguda de colon izquierdo requiere pruebas con alto valor pronóstico. Los objetivos del estudio son analizar la utilidad de la ecografía como método diagnóstico inicial y evaluar la validez de las clasificaciones actuales de gravedad de dicha enfermedad.
Estudio observacional retrospectivo de pacientes con diverticulitis aguda de colon izquierdo. Se solicitó ecografía o tomografía computarizada (TC) siguiendo un algoritmo clínico. Tras los hallazgos de imagen, se clasificó la enfermedad como leve, localmente complicada y complicada. Se evaluaron la eficacia de la ecografía como herramienta diagnóstica inicial y las razones por las que se realizó una TC como técnica inicial. Se compararon los hallazgos con las clasificaciones de diverticulitis publicadas.
De 311 pacientes con diverticulitis aguda, se seleccionaron 183 con diverticulitis aguda de colon izquierdo, que fueron clasificadas por imagen como leves (104), localmente complicadas (60) y complicadas (19). En 98 pacientes, el diagnóstico se realizó por ecografía, en 77 por TC y en 8 mediante ambas. Las principales razones de utilización inicial de TC fueron falta de experiencia del radiólogo en ecografía abdominal y falta de disponibilidad de un radiólogo de guardia. A 6 pacientes diagnosticados por ecografía se les realizó una nueva evaluación por TC, pero solo en 3 cambió la clasificación. Ninguna de las clasificaciones publicadas recoge todos los hallazgos en imagen.
La ecografía debería ser la primera técnica a utilizar para el diagnóstico de diverticulitis aguda de colon izquierdo. Para establecer el pronóstico de la enfermedad, son útiles diversos parámetros analíticos y hallazgos de imagen. Para una apropiada toma de decisión terapéutica se necesitarían nuevas clasificaciones de gravedad.
In this paper we present an integral solution for law-compliance privacy-protection into trust models for agent systems. Several privacy issues are concerned into trust relationships. Specifically, ...we define which privacy rights must legally be guaranteed in trusting communities of agents. From them, we describe additional interaction protocols that are required to implement such guarantees. Next, we apply additional message exchanges into a specific application domain (the Agent Trust and Reputation testbed) using JADE agent platform. The decisions about how to apply these control mechanisms (about when to launch the corresponding JADE protocol) has been efficiently carried out by neural computing. It uses past behavior of agents to decide (classify) which agents are worthy to share privacy with, considering which number of past interactions we should take into account. Furthermore, we also enumerate the corresponding privacy violations that would have taken place if these control mechanisms (in form of interaction protocols) were ignored or misused. From the possible existence of privacy violations, a regulatory structure is required to address (prevent and fix) the corresponding harmful consequences. We use Islander (an electronic institution editor) to formally define the scenes where privacy violation may be produced, attached to the ways to repair it: the defeasible actions that could voluntarily reduce or eliminate the privacy damage, and the obligations that the electronic institution would impose as penalties.
Abstract Blunt cardiac trauma (BCT) includes a number of diseases ranging from clinically silent arrhythmias to lethal cardiac wall rupture. The most common form is “cardiac contusion”, which is ...currently under debate. The absence of a clear definition and the lack of diagnostic tests of choice make diagnosing cardiac contusion difficult. We present the case report of a healthy young patient who went to the emergency department with electrocardiogram changes following blunt chest trauma, and review the current literature on the subject.
Background
Plasma cell neoplasms are characterized by the proliferation of a single clone of plasma cells with production of a monoclonal immunoglobulin. They can manifest as a single lesion ...(plasmacytoma) or as multiple lesions (multiple myeloma).
Methods
Paraffin‐embedded tissue blocks of patients microscopically diagnosed with plasma cell neoplasms in the jaws were retrieved from five pathology files. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed and follow‐up status were retrieved from the pathology reports.
Results
Fifty‐two cases were retrieved (mean age: 59.4 years) without sex predilection. The mandible was the most affected site (67.3%), usually associated with pain and/or paresthesia (53.8%). Lesions in other bones besides the jaws were reported for 24 patients (46.2%). Radiographically, tumours usually presented as poorly defined osteolytic lesions with unilocular or multilocular images, while microscopy revealed diffuse proliferation of neoplastic plasma cells with nuclear displacement and abundant eosinophilic cytoplasm. Two cases were classified as anaplastic, and amyloid deposits were found in two other cases. Immunohistochemistry was positive for plasma cell markers and negative for CD20 and CD3, and monoclonality for kappa light chain predominated. The overall survival rate after 5 years of follow‐up was 26.6%.
Conclusion
Plasma cell neoplasms are aggressive tumours with a poor prognosis and involvement of the jaws may be the first complaint of the patient. Thus, oral pathologists, head and neck surgeons and dentists should be aware of their clinical, radiographic and microscopic manifestations.
Neurogenesis persists in certain regions of the adult brain including the subgranular zone of the hippocampal dentate gyrus wherein its regulation is essential, particularly in relation to learning, ...stress and modulation of mood. Lysophosphatidic acid (LPA) is an extracellular signaling phospholipid with important neural regulatory properties mediated by specific G protein-coupled receptors, LPA(1-5). LPA(1) is highly expressed in the developing neurogenic ventricular zone wherein it is required for normal embryonic neurogenesis, and, by extension may play a role in adult neurogenesis as well. By means of the analyses of a variant of the original LPA(1)-null mutant mouse, termed the Malaga variant or "maLPA(1)-null," which has recently been reported to have defective neurogenesis within the embryonic cerebral cortex, we report here a role for LPA(1) in adult hippocampal neurogenesis. Proliferation, differentiation and survival of newly formed neurons are defective in the absence of LPA(1) under normal conditions and following exposure to enriched environment and voluntary exercise. Furthermore, analysis of trophic factors in maLPA(1)-null mice demonstrated alterations in brain-derived neurotrophic factor and insulin growth factor 1 levels after enrichment and exercise. Morphological analyses of doublecortin positive cells revealed the anomalous prevalence of bipolar cells in the subgranular zone, supporting the operation of LPA(1) signaling pathways in normal proliferation, maturation and differentiation of neuronal precursors.
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