895 resultados para Beltrán, Rafael


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Interview with Steve Larkin examining the architecture of House at Bogwest. Specifically in relation to use of zenithal light. Article text by Rafael Suriani. Includes photographs by Alice Clancy

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Quantum coherence between electron and ion dynamics, observed in organic semiconductors by means of ultrafast spectroscopy, is the object of recent theoretical and computational studies. To simulate this kind of quantum coherent dynamics, we have introduced in a previous article [L. Stella, M. Meister, A. J. Fisher, and A. P. Horsfield, J. Chem. Phys. 127, 214104 (2007)] an improved computational scheme based on Correlated Electron-Ion Dynamics (CEID). In this article, we provide a generalization of that scheme to model several ionic degrees of freedom and many-body electronic states. To illustrate the capability of this extended CEID, we study a model system which displays the electron-ion analog of the Rabi oscillations. Finally, we discuss convergence and scaling properties of the extended CEID along with its applicability to more realistic problems. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3589165]

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We consider a model of an on-line software market, where an intermediary distributes products from sellers to buyers. When products of sellers are vertically differentiated, an intermediary, earning a proportion of sales, has an incentive to hide the worse product on the second page, and only keep the better product on the front page: that weakens the competition, allowing the seller with the better product to charge a higher price. With heterogeneous visiting costs to the second page, the platform's revenue might improve, but the outcome will become socially suboptimal.

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Two models that can predict the voltage-dependent scattering from liquid crystal (LC)-based reflectarray cells are presented. The validity of both numerical techniques is demonstrated using measured results in the frequency range 94-110 GHz. The most rigorous approach models, for each voltage, the inhomogeneous and anisotropic permittivity of the LC as a stratified media in the direction of the biasing field. This accounts for the different tilt angles of the LC molecules inside the cell calculated from the solution of the elastic problem. The other model is based on an effective homogeneous permittivity tensor that corresponds to the average tilt angle along the longitudinal direction for each biasing voltage. In this model, convergence problems associated with the longitudinal inhomogeneity are avoided, and the computation efficiency is improved. Both models provide a correspondence between the reflection coefficient (losses and phase-shift) of the LC-based reflectarray cell and the value of biasing voltage, which can be used to design beam scanning reflectarrays. The accuracy and the efficiency of both models are also analyzed and discussed.

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Haematological malignancies (HM) represent over 6% of the total cancer incidence in Europe and affect all ages, ranging between 45% of all cancers in children and 7% in the elderly. Thirty per cent of childhood cancer deaths are due to HM, 8% in the elderly. Their registration presents specific challenges, mainly because HM may transform or progress in the course of the disease into other types of HM. In the context of cancer registration decisions have to be made about classifying subsequent notifications on the same patient as the same tumour (progression), a transformation or a new tumour registration. Allocation of incidence date and method of diagnosis must also be standardised. We developed European Network of Cancer Registries (ENCR) recommendations providing specific advice for cancer registries to use haematology and molecular laboratories as data sources, conserve the original date of incidence in case of change of diagnosis, make provision for recording both the original as well as transformed tumour and to apply precise rules for recording and counting multiple diagnoses. A reference table advising on codes which reflect a potential transformation or a new tumour is included. This work will help to improve comparability of data produced by population-based cancer registries, which are indispensable for aetiological research, health care planning and clinical research, an increasing important area with the application of targeted therapies.

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Background: More effective treatments have become available for haematological malignancies from the early 2000s, but few large-scale population-based studies have investigated their effect on survival. Using EUROCARE data, and HAEMACARE morphological groupings, we aimed to estimate time trends in population-based survival for 11 lymphoid and myeloid malignancies in 20 European countries, by region and age. Methods: In this retrospective observational study, we included patients (aged 15 years and older) diagnosed with haematological malignancies, diagnosed up to Dec 31, 2007, and followed up to Dec 31, 2008. We used data from the 30 cancer registries (across 20 countries) that provided continuous incidence and good quality data from 1992 to 2007. We used a hybrid approach to estimate age-standardised and age-specific 5-year relative survival, for each malignancy, overall and for five regions (UK, and northern, central, southern, and eastern Europe), and four 3-year periods (1997–99, 2000–02, 2003–05, 2006–08). For each malignancy, we also estimated the relative excess risk of death during the 5 years after diagnosis, by period, age, and region. Findings: We analysed 560 444 cases. From 1997–99 to 2006–08 survival increased for most malignancies: the largest increases were for diffuse large B-cell lymphoma (42·0% [95% CI 40·7–43·4] to 55·4% [54·6–56·2], p<0·0001), follicular lymphoma (58·9% [57·3–60·6] to 74·3% [72·9–75·5], p<0·0001), chronic myeloid leukaemia (32·3% [30·6–33·9] to 54·4% [52·5–56·2], p<0·0001), and acute promyelocytic leukaemia (50·1% [43·7–56·2] to 61·9% [57·0–66·4], p=0·0038, estimate not age-standardised). Other survival increases were seen for Hodgkin's lymphoma (75·1% [74·1–76·0] to 79·3% [78·4–80·1], p<0·0001), chronic lymphocytic leukaemia/small lymphocytic lymphoma (66·1% [65·1–67·1] to 69·0% [68·1–69·8], p<0·0001), multiple myeloma/plasmacytoma (29·8% [29·0–30·6] to 39·6% [38·8–40·3], p<0·0001), precursor lymphoblastic leukaemia/lymphoma (29·8% [27·7–32·0] to 41·1% [39·0–43·1], p<0·0001), acute myeloid leukaemia (excluding acute promyelocytic leukaemia, 12·6% [11·9–13·3] to 14·8% [14·2–15·4], p<0·0001), and other myeloproliferative neoplasms (excluding chronic myeloid leukaemia, 70·3% [68·7–71·8] to 74·9% [73·8–75·9], p<0·0001). Survival increased slightly in southern Europe, more in the UK, and conspicuously in northern, central, and eastern Europe. However, eastern European survival was lower than that for other regions. Survival decreased with advancing age, and increased with time only slightly in patients aged 75 years or older, although a 10% increase in survival occurred in elderly patients with follicular lymphoma, diffuse large B-cell lymphoma, and chronic myeloid leukaemia. Interpretation: These trends are encouraging. Widespread use of new and more effective treatment probably explains much of the increased survival. However, the persistent differences in survival across Europe suggest variations in the quality of care and availability of the new treatments. High-resolution studies that collect data about stage at diagnosis and treatments for representative samples of cases could provide further evidence of treatment effectiveness and explain geographic variations in survival.

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The rock/atmosphere interface is inhabited by a complex microbial community including bacteria, algae and fungi. These communities are prominent biodeterioration agents and remarkably influence the status of stone monuments and buildings. Deeper comprehension of natural biodeterioration processes on stone surfaces has brought about a concept of complex microbial communities referred to as "subaerial biofilms". The practical implications of biofilm formation are that control strategies must be devised both for testing the susceptibility of the organisms within the biofilm and treating the established biofilm. Model multi-species biofilms associated with mineral surfaces that are frequently refractory to conventional treatment have been used as test targets. A combination of scanning microscopy with image analysis was applied along with traditional cultivation methods and fluorescent activity stains. Such a polyphasic approach allowed a comprehensive quantitative evaluation of the biofilm status and development. Effective treatment strategies incorporating chemical and physical agents have been demonstrated to prevent biofilm growth in vitro. Model biofilm growth on inorganic support was significantly reduced by a combination of PDT and biocides

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The peculiar object P/2010A2 was discovered in January 2010 and given a cometary designation because of the presence of a trail of material, although there was no central condensation or coma. The appearance of this object, in an asteroidal orbit (small eccentricity and inclination) in the inner main asteroid belt attracted attention as a potential new member of the recently recognized class of main-belt comets. If confirmed, this new object would expand the range in heliocentric distance over which main-belt comets are found. Here we report observations of P/2010A2 by the Rosetta spacecraft. We conclude that the trail arose from a single event, rather than a period of cometary activity, in agreement with independent results. The trail is made up of relatively large particles of millimetre to centimetre size that remain close to the parent asteroid. The shape of the trail can be explained by an initial impact ejecting large clumps of debris that disintegrated and dispersed almost immediately. We determine that this was an asteroid collision that occurred around 10 February 2009.

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Introduction: Because a dose–response relationship is characteristic of conventional chemotherapy, this concept is widely used for the development of novel cytotoxic (CTX) drugs. However, the need to reach the MTD to obtain optimal benefit with molecularly targeted agents (MTA) is controversial. In this study, we evaluated the relationship between dose and efficacy in a large cohort of phase I patients with solid tumors.

Experimental Design: We collected data on 1,182 consecutive patients treated in phase I trials in 14 European institutions in 2005–2007. Inclusion criteria were: (i) patients treated within completed single-agent studies in which a maximum-administered dose was defined and (ii) RECIST/survival data available.

Results: Seventy-two percent of patients were included in trials with MTA (N = 854) and 28% in trials with CTX (N = 328). The objective response (OR) rate was 3% and disease control at 6 months was 11%. OR for CTX was associated with higher doses (median 92% of MTD); this was not the case for MTA, where patients achieving OR received a median of 50% of MTD. For trials with MTA, patients treated at intermediate doses (40%–80%) had better survival compared with those receiving low or high doses (P = 0.038). On the contrary, there was a direct association between higher dose and better OS for CTX agents (P = 0.003).

Conclusion: Although these results support the development of novel CTX based on MTD, we found no direct relationship between higher doses and response with MTA in unselected patients. However, the longest OS was seen in patients treated with MTA at intermediate doses (40%–80% of MTD)

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OBJECTIVES: The International Cancer Benchmarking Partnership (ICBP) is a collaboration between 6 countries and 12 jurisdictions with similar primary care-led health services. This study investigates primary care physician (PCP) behaviour and systems that may contribute to the timeliness of investigating for cancer and subsequently, international survival differences.

DESIGN: A validated survey administered to PCPs via the internet set out in two parts: direct questions on primary care structure and practice relating to cancer diagnosis, and clinical vignettes, assessing management of scenarios relating to the diagnosis of lung, colorectal or ovarian cancer.

PARTICIPANTS: 2795 PCPs in 11 jurisdictions: New South Wales and Victoria (Australia), British Columbia, Manitoba, Ontario (Canada), England, Northern Ireland, Wales (UK), Denmark, Norway and Sweden.

PRIMARY AND SECONDARY OUTCOME MEASURES: Analysis compared the cumulative proportion of PCPs in each jurisdiction opting to investigate or refer at each phase for each vignette with 1-year survival, and conditional 5-year survival rates for the relevant cancer and jurisdiction. Logistic regression was used to explore whether PCP characteristics or system differences in each jurisdiction affected the readiness to investigate.

RESULTS: 4 of 5 vignettes showed a statistically significant correlation (p<0.05 or better) between readiness to investigate or refer to secondary care at the first phase of each vignette and cancer survival rates for that jurisdiction. No consistent associations were found between readiness to investigate and selected PCP demographics, practice or health system variables.

CONCLUSIONS: We demonstrate a correlation between the readiness of PCPs to investigate symptoms indicative of cancer and cancer survival rates, one of the first possible explanations for the variation in cancer survival between ICBP countries. No specific health system features consistently explained these findings. Some jurisdictions may consider lowering thresholds for PCPs to investigate for cancer-either directly, or by specialist referral, to improve outcomes.

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In most countries, diabetic retinopathy is the most frequently occurring complication of diabetes mellitus and remains a leading cause of vision loss globally. Its etiology and pathology have been extensively studied for half a century, yet there are disappointingly few therapeutic options. Although some new treatments have been introduced for diabetic macular edema (DME) (e.g. intravitreal vascular endothelial growth factor inhibitors ('anti-VEGFs') and new steroids), up to 50% of patients fail to respond. Furthermore, for people with proliferative diabetic retinopathy (PDR), laser photocoagulation remains a mainstay therapy, even though it is inherently a destructive procedure. This review summarizes the clinical features of diabetic retinopathy and its risk factors. It describes details of retinal pathology and the cell culture approaches and animal models that are used to mimic its key components, advance understanding of its pathogenesis, and enable identification of new therapeutic targets. We emphasise that although there have been significant advances, there is still a pressing need for a better understanding basic mechanisms to enable development of reliable and robust means to identify patients at highest risk, and to intervene effectively before vision loss occurs.

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BACKGROUND: Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control.

METHODS: Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights.

FINDINGS: 5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease.

INTERPRETATION: International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems.


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O presente relatório de conclusão do curso de Mestrado Integrado em Medicina Veterinária da Universidade de Évora, refere-se ao período de estágio curricular obrigatório que decorreu na Clínica Equifort, em Fortaleza, Brasil, na área Patologia e Clínica de Equinos. Numa primeira fase é feita uma descrição das atividades desenvolvidas onde se apresenta a casuística acompanhada durante o estágio, que inclui atividades em diversas áreas como medicina desportiva, clínica médica, clínica reprodutiva, clínica cirúrgica e clínica hospitalar. Numa segunda fase desenvolve-se uma monografia onde se caracterizam as lesões radiográficas de membros anteriores de cavalos de desporto, e por fim são apresentados cinco casos clínicos; ABSTRACT: EQUINE PATHOLOGY AND CLINICAL The present report refers to curricular internship, integrated on the master degree in veterinary medicine at the University of Évora, that took place at the Clinic Equifort in Fortaleza, Brazil, in the área of Equine Pathology and Clinical. Initially a description of the activities accompanied during the internship is given which includes activities in areas such as sports medicine, internal medicine, reprodution and surgery. In a second part a monograph is developd with the characterization of radiographic injuries in forelimbs of sport’s horses, and finally five clinical cases are presented.

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No actual cenário de perda acelerada de biodiversidade, o nosso conhecimento dos ecossistemas marinhos, apesar da sua extensão e complexidade, continua muito inferior ao dos ecossistemas terrestres. A classe Malacostraca (Arthropoda, Crustacea), um grupo dos mais representativos nos ecossistemas marinhos, apresenta um elevado nível de diversidade morfológica e ecológica, mas difícil sua identificação ao nível de espécie requer frequentemente a ajuda de especialistas em taxonomia. A utilização recente do “barcoding” (código de barras do ADN), revelou ser um método rápido e eficaz para a identificação de espécies em diversos grupos de metazoários, incluindo os Malacostraca. No âmbito desta tese foi construída uma base de dados de código de barras de ADN envolvendo 132 espécies de Malacostraca vários locais de amostragem no Atlântico Nordeste e Mediterrâneo. As sequências de ADN mitocondrial provenientes de 601 espécimes formaram, em 95% dos casos, grupos congruentes com as identificações baseadas em características morfológicas. No entanto, foi detectado polimorfismo em seis casos e a divergência intra-específica foi elevada em exemplares pertencentes a duas espécies morfológicas, sugerindo, neste caso, a ocorrência de especiação críptica. Este estudo confirma a utilidade do código de barras de ADN para a identificação de Malacostraca marinhos. Apesar do sucesso obtido, este método apresenta alguns problemas, como por exemplo a possível amplificação de pseudogenes. A ocorrência de pseudogenes e as possíveisabordagens para a detecção e resolução deste tipo de problemas são discutidas com base em casos de estudo: análises dos códigos de barras ADN na espécie Goneplax rhomboides (Crustacea, Decapoda). A análise dos códigos de barras ADN revelou ainda grupos prioritários de decápodes para estudos taxonómicos e sistemáticos, nomeadamente os decápodes dos géneros Plesionika e Pagurus. Neste âmbito são discutidas as relações filogenéticas entre espécies seleccionadas dos géneros Plesionika e Pagurus. Este trabalho aponta para várias questões no âmbito da biodiversidade e evolução molecular da classe Malacostraca que carecem de um maior esclarecimento, podendo ser considerado como a base para estudo futuros. Análises filogenéticas adicionais integrando dados morfológicos e moleculares de um maior número de espécies e de famílias deverão certamente conduzir a uma melhor avaliação da biodiversidade e da evolução dentro da classe.