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Search Results: 1 - 10 of 22314 matches for " Joao Pereira-Correia "
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Searching for the Lost Ostium: A Morphometric Analysis of the Ureteral Ostia Distribution in Normal and Thickened Bladders and Its Applications in Endourology  [PDF]
Mariana Greco, Paula Marsillac, Julia Vieira, Mario Brito, Andre Saud, Rafael Prinz, Joao Pereira-Correia
Open Journal of Urology (OJU) , 2013, DOI: 10.4236/oju.2013.33028
Abstract:

Introduction: The ureteral ostia may not be easily identified in urological endoscopic procedures, leading to an incomplete diagnosis of urinary tract diseases or a predisposition to iatrogenic lesions. The purpose of our study is to evaluate the anatomical distribution of ureteralostia in normal bladders and those with thickened walls. Materials and Methods: We dissected 30 vesical-prostate blocks from human cadavers and identified the ostia of the bladder trigone. A computerized morphometric analysis was performed to measure the thickness of the detrusor muscle, the distances between the ureteral ostia themselves and the distances between each ureteral ostium (left—LUO and right—RUO) and the internal urethral ostium (IUO). The angle formed between the IUO and LUO/RUO was also recorded as well as the volume of the prostates. Results: Fifteen bladders with a non-thickened detrusor (<5 mm) as well as 15 bladders with muscular thickening (>6 mm) were identified. The average prostatic volume of the dissected blocks was 23.7 cm3. The distance between ureteral ostia, the distance from IUO to LUO, the distance from IUO to RUO and the angle formed between IUO and LUO/RUO in normal and thickened bladder were, respectively, 1.9 cm/2.2 cm (p = 0.09), 1.6 cm/1.6 cm (p = 0.82), 1.6 cm/1.7 cm (p = 0.79) and 77/91 (p = 0.17). Conclusions: Our study shows that there is no significant difference in the position of bladder ostia in healthy and thickened bladders. We believe that our findings may facilitate locating the ureteral orifices in situations where endoscopic identification is difficult.

Beta Function Constraints from Renormalization Groups Flows in Spin Systems
Joao D. Correia
Physics , 1998,
Abstract: Inspired by previous work on the constraints that duality imposes on beta functions of spin models, we propose a consistency condition between those functions and RG flows at different points in coupling constant space. We show that this consistency holds for a non self-dual model which admits an exact RG flow, but that it is violated when the RG flow is only approximate. We discuss the use of this deviation as a test for the ``goodness'' of proposed RG flows in complicated models, and the use of the proposed consistency in suggesting RG equations.
On QCD_2 from supergravity and mass gaps in QCD
Joao Correia,Troels Harmark
Physics , 1999, DOI: 10.1016/S0370-2693(99)00813-8
Abstract: As a test of the conjectured QCD/supergravity duality, we consider mass gaps in the supergravity construction of QCD_2. We find a mass gap in the dual field theory both when using non-rotating and rotating black D2-branes as backgrounds in the supergravity construction of QCD_2. So, since pure QCD_2 does not have a mass gap, the dual field theory of the supergravity construction of QCD_2 cannot be pure QCD_2. Considering the mass scales in the dual field theory of the supergravity construction of QCD_2, we find that this is explainable both in the case of the non-rotating background and of the rotating background. In particular, the mass gap in the case of the rotating background can be explained using results of the large angular momentum limit of euclidean rotating branes, obtained recently by Cvetic and Gubser. We furthermore remark on the possible implications for the mass gaps in the supergravity constructions of QCD_3 and QCD_4.
The spectral dimension of non-generic branched polymers
John F. Wheater,Joao Correia
Physics , 1998, DOI: 10.1016/S0920-5632(99)85202-5
Abstract: We show that the spectral dimension on non-generic branched polymers with positive susceptibility exponent is given by $d_s=2/(1+\gamma)$. For those models with $\gamma<0$ we find that $d_s=2$.
Control of allergic rhinitis and asthma test – a formal approach to the development of a measuring tool
Luis Nogueira-Silva, Sonia V Martins, Ricardo Cruz-Correia, Luis F Azevedo, Mario Morais-Almeida, António Bugalho-Almeida, Marianela Vaz, Altamiro Costa-Pereira, Joao A Fonseca
Respiratory Research , 2009, DOI: 10.1186/1465-9921-10-52
Abstract: To describe the studies conducted to design the control of ARA test (CARAT) questionnaire.We performed a literature review to generate a list of potentially important items for the assessment of control of ARA. A formal consensus development process, that used an innovative web-based application, was designed – 111 experts in ARA and 60 patients participated. At the final consensus meeting, 25 primary and secondary care physicians formulated the questions and response options. A qualitative feasibility study (n = 31 patients) was conducted to evaluate the comprehensibility of the questionnaire while testing two different designs.Thirty-four potentially important items were identified. All the steps of the consensus process were completed in 2.5 months. The opinions of experts and patients lead to the formulation of 17 questions. At the feasibility study the instructions and wording problems were corrected and a semi-tabular format was chosen.A tool to measure the control of allergic rhinitis and asthma was developed using a comprehensive set of methodological steps ensuring the design quality and the face and content validity. Additional validation studies to assess the psychometric properties of the questionnaire have started.Allergic rhinitis and asthma (ARA) are inflammatory diseases and are often associated. The lack of control of these diseases is responsible for a significant loss in patient's quality of life and an important socioeconomic burden [1,2]. According to international guidelines, achievement of disease control is the primary goal for the treatment of allergic respiratory diseases [1,3]. Allergic Rhinitis and its Impact on Asthma (ARIA) [1] guidelines have recently emphasized in the importance of a combined approach for both evaluation and management of ARA. Thus, measurement of disease control should consider, concurrently, the pathologies of upper and lower airways [4].Based on the definition of asthma control of the Global Initiative for Asthma [
Three-State Complex Valued Spins Coupled to Binary Branched Polymers in Two-Dimensional Quantum Gravity
Joao D. Correia,John F. Wheater
Physics , 1997, DOI: 10.1016/S0920-5632(97)00894-3
Abstract: A model of complex spins (corresponding to a non-minimal model in the language of CFT) coupled to the binary branched polymer sector of quantum gravity is considered. We show that this leads to new behaviour.
The Spectral Dimension of Non-generic Branched Polymer Ensembles
Joao D. Correia,John F. Wheater
Physics , 1997, DOI: 10.1016/S0370-2693(98)00055-0
Abstract: We show that the spectral dimension on non-generic branched polymer models with susceptibility exponent $\gamma$ is given by $2/(1+\gamma)$. For those models with negative $\gamma$ we find that the spectral dimension is 2.
A Practical and Automated Hall Magnetometer for Characterization of Magnetic Materials  [PDF]
Jefferson F. D. F. Araujo, Joao M. B. Pereira
Modern Instrumentation (MI) , 2015, DOI: 10.4236/mi.2015.44005
Abstract: A versatile Hall magnetometer has been developed, manufactured, calibrated, and turned operational for measurements of the magnetic properties of bulk materials and magnetic micro- and nanoparticles. The magnetometer was constructed from the combination of various equipments, which was usually available in most laboratories, such as a Hall effect sensor, an electromagnet, a current source, and a linear actuator. The achieved sensitivity to the magnetic moment was approximately 10-8 Am2. The results were compared to measurements performed with commercial vibrating-sample magnetometers and superconductor quantum interference devices (SQUID) and showed errors of around 1.7% and a standard deviation of 1.2% in relation to measures themselves. The constructed Hall magnetometer records a magnetic hysteresis loop of up to 1.2 T at room temperature. This magnetometer is cost-effective, versatile, and suitable for research.
Video Object Relevance Metrics for Overall Segmentation Quality Evaluation
Correia Paulo,Pereira Fernando
EURASIP Journal on Advances in Signal Processing , 2006,
Abstract: Video object segmentation is a task that humans perform efficiently and effectively, but which is difficult for a computer to perform. Since video segmentation plays an important role for many emerging applications, as those enabled by the MPEG-4 and MPEG-7 standards, the ability to assess the segmentation quality in view of the application targets is a relevant task for which a standard, or even a consensual, solution is not available. This paper considers the evaluation of overall segmentation partitions quality, highlighting one of its major components: the contextual relevance of the segmented objects. Video object relevance metrics are presented taking into account the behaviour of the human visual system and the visual attention mechanisms. In particular, contextual relevance evaluation takes into account the context where an object is found, exploiting, for instance, the contrast to neighbours or the position in the image. Most of the relevance metrics proposed in this paper can also be used in contexts other than segmentation quality evaluation, such as object-based rate control algorithms, description creation, or image and video quality evaluation.
Geographic Concentration in Portugal and Regional Specific Factors
Vitor Joao Pereira Domingues Martinho
Quantitative Finance , 2011,
Abstract: This paper pretends to analyze the importance which the natural advantages and local resources are in the manufacturing industry location, in relation with the "spillovers" effects and industrial policies. To this, we estimate the Rybczynski equation matrix for the various manufacturing industries in Portugal, at regional level (NUTS II) and for the period 1980 to 1999. Estimations are displayed with the model mentioned and for four different periods, namely 1980 to 1985, from 1986 to 1994, from 1980 to 1994 and from 1995 to 1999. The consideration of the various periods until 1994, aims to capture the effects of our entrance at the, in that time, EEC (European Economic Community) and the consideration of a period from 1995 is because the change in methodology for compiling statistical data taken from this time in Portugal. As a summary conclusion, noted that the location of manufacturing in Portugal is still mostly explained by specific factors, with a tendency to increase in some cases the explanation by these factors, having the effect "spillovers" and industrial policies little importance in this context.
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