3,730 research outputs found
On Useful Conformal Tranformations In General Relativity
Local conformal transformations are known as a useful tool in various
applications of the gravitational theory, especially in cosmology. We describe
some new aspects of these transformations, in particular using them for
derivation of Einstein equations for the cosmological and Schwarzschild
metrics. Furthermore, the conformal transformation is applied for the
dimensional reduction of the Gauss-Bonnet topological invariant in to the
spaces of lower dimensions.Comment: 17 pages, LaTeX. The paper is intended mainly for pedagogical
purposes and represents a collection of exercises concerning local conformal
transformations and dimensional reduction. To be published in "Gravitation
and Cosmology
Long‐Term Survival After Choriocarcinoma Transmitted by Liver Graft: A Successful Report in Pediatric Transplantation
Background: LT is the standard of care for many pediatric liver disorders. Although long-term outcomes have improved, some rare complications such as transmission of occult donor tumors have been reported.
Case report: An adolescent diagnosed with tyrosinemia was submitted to LT from a previous healthy donor due to HCC. Almost 8 months after LT, the patient presented a nodular hepatic lesion. Clinically, he had mild weight loss, lower limb edema, and gynecomastia. Thorax CT found lesions in the left lung parenchyma, which showed no increased uptake in PET SCAN. Liver biopsy revealed a carcinoma with desmoplastic stroma. ISS was withdrawn, and palliative chemotherapy was started for presumptive HCC relapse. AFP remained normal, but HCG had reached unexpected values of 1984 IU/L. As we requested detailed information about the other organ recipients from the same donor, we found that one of them passed away due to disseminated tumor. Five months after the beginning of chemotherapy, the patient underwent resection of liver segments V and VI. Histological examination confirmed liver metastatic choriocarcinoma. At the time of writing, with 11 years of follow-up, the patient had sustained remission with no signs of relapse.
Discussion: This case reports a diagnostic challenge in an adolescent with a particular unique background and a very rare pattern of tumor transmission. The authors aim to highlight the risk of cancer-bearing organs reveled post-LT and to testimony the experience of the successful outcome after a choriocarcinoma transmitted by liver graft.info:eu-repo/semantics/publishedVersio
Cerenkov angle and charge reconstruction with the RICH detector of the AMS experiment
The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the
International Space Station (ISS) will be equipped with a proximity focusing
Ring Imaging Cerenkov (RICH) detector, for measurements of particle electric
charge and velocity. In this note, two possible methods for reconstructing the
Cerenkov angle and the electric charge with the RICH, are discussed. A
Likelihood method for the Cerenkov angle reconstruction was applied leading to
a velocity determination for protons with a resolution of around 0.1%. The
existence of a large fraction of background photons which can vary from event
to event, implied a charge reconstruction method based on an overall efficiency
estimation on an event-by-event basis.Comment: Proceedings submitted to RICH 2002 (Pylos-Greece
High-risk pulmonary embolism with right heart thrombi
Accuracy is essential to surface quality control when a range sensor is applied to measure the 3D shape of an automotive body part. A sensor's viewing pose, including location and orientation, is related to measurement accuracy. It is usually difficult to find an optimal solution by manual control of sensor viewpoints. A CAD-guided robot view planner developed previously can automatically generate viewpoints. Measurement accuracy can be satisfied in a certain range. However, the unpredictable image noises, especially in regions with low intensity contrast, cannot be compensated by the CADguided robot view planner. In another aspect, measurement accuracy is evaluated all over the part surface. The local accuracy of a small patch may exceed the measurement tolerance. In this paper, feedback design is applied to the CADguided robot sensor planning system. The feedback controller can evaluate the accuracy of obtained point clouds, identify problem regions, and generate new viewpoints. This process is recursively executed until the measurement accuracy reaches to a tolerant value. This feedback-based inspection system had been implemented in previous work to fill holes of a point cloud, which are caused by shadows and light reflections. In this paper, the feedback controller is specifically designed to improve the measurement accuracy. Experimental results show the success of applying this feedback system for dimensional inspection of an automotive body part. © 2007 IEEE.Link_to_subscribed_fulltex
Abordagem Multidisciplinar do Primeiro Caso Autóctone de Tularémia Notificado em Portugal
Case ReportFrancisella tularensis, a Gram-negative coccobacillus, is a highly virulent pathogen responsible for several zoonotic outbreaks in Europe
in the last few decades. The authors report the case of a 46-year-old male who developed fever, myalgias and headache a week
after having contact with animal feed contaminated by rodents. Serological tests were positive for Francisella tularensis. This first case
of autochthonous tularemia in Portugal led to an intensive investigation involving several healthcare services and national governmental
authorities. The authors address the possible underdiagnosis of this infection in the country.Francisella tularensis, um cocobacilo Gram-negativo, é um microrganismo infecioso altamente virulento, responsável por vários surtos
de doença na Europa nas últimas décadas. Os autores apresentam o caso de um homem de 46 anos com febre, mialgias e cefa-
leias cerca de uma semana após contacto com ração de animais contaminada por roedores. O estudo serológico foi positivo para
Francisella tularensis. Este caso, o primeiro caso de tularémia autóctone notificado em Portugal, originou uma intensa investigação
envolvendo diversas autoridades de saúde e governamentais portuguesas. Os autores alertam para a possibilidade de subdiagnóstico
desta doença no país.info:eu-repo/semantics/publishedVersio
Prosodic, syntactic, semantic guidelines for topic structures across domains and corpora
This paper presents the annotation guidelines applied to naturally occurring speech, aiming at an integrated account of contrast and parallel structures in European Portuguese. These guidelines were defined to allow for the empirical study of interactions among intonation and syntax-discourse patterns in selected sets of different corpora (monologues and dialogues, by adults and teenagers). In this paper we focus on the multilayer annotation process of left periphery structures by using a small sample of highly spontaneous speech in which the distinct types of topic structures are displayed. The analysis of this sample provides fundamental training and testing material for further application in a wider range of domains and corpora. The annotation process comprises the following time-linked levels (manual and automatic): phone, syllable and word level transcriptions (including co-articulation effects); tonal events and break levels; part-of-speech tagging; syntactic-discourse patterns (construction type; construction position; syntactic function; discourse function), and disfluency events as well. Speech corpora with such a multi-level annotation are a valuable resource to look into grammar module relations in language use from an integrated viewpoint. Such viewpoint is innovative in our language, and has not been often assumed by studies for other languages.info:eu-repo/semantics/acceptedVersio
Predictive analysis in healthcare: emergency wait time prediction
Emergency departments are an important area of a hospital, being the major entry point to the healthcare system. One of the most important issues regarding patient experience are the emergency department waiting times. In order to help hospitals improving their patient experience, the authors will perform a study where the Random Forest algorithm will be applied to predict emergency department waiting times. Using data from a Portuguese hospital from 2013 to 2017, the authors discretized the emergency waiting time in 5 different categories: “Really Low”, “Low”, “Average”, “High”, “Really High”. Plus, the authors considered as waiting time, the time from triage to observation. The authors expect to correctly evaluate the proposed classification algorithm efficiency and accuracy in order to be able to conclude if it is valuable when trying to predict ED waiting times.info:eu-repo/semantics/acceptedVersio
Emergency waiting times data analysis
The Emergency Departments (ED) are a complex and important area of a hospital. With limited resources, it is mandatory to focus on efficiency. When hospitals are unable to deal with high demand, problems may
rise leading to longer waiting times and more dissatisfaction. In this research, the authors extracted knowledge from a hospital ED, through data analysis and data mining, applying Random Forest and Naïve Bayes to study the ED patient waiting time and diseases.info:eu-repo/semantics/publishedVersio
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