81 research outputs found

    Relativistic Quantum Thermodynamics of Ideal Gases in 2 Dimensions

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    In this work we study the behavior of relativistic ideal Bose and Fermi gases in two space dimensions. Making use of polylogarithm functions we derive a closed and unified expression for their densities. It is shown that both type of gases are essentially inequivalent, and only in the non-relativistic limit the spinless and equal mass Bose and Fermi gases are equivalent as known in the literature.Comment: 6 pages, 1 figur

    Energy-momentum tensor in thermal strong-field QED with unstable vacuum

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    The mean value of the one-loop energy-momentum tensor in thermal QED with electric-like background that creates particles from vacuum is calculated. The problem differes essentially from calculations of effective actions (similar to that of Heisenberg--Euler) in backgrounds that do not violate the stability of vacuum. The role of a constant electric background in the violation of both the stability of vacuum and the thermal character of particle distribution is investigated. Restrictions on the electric field and its duration under which one can neglect the back-reaction of created particles are established.Comment: 7 pages, Talk presented at Workshop "Quantum Field Theory under the Influence of External Conditions", Leipzig, September 17-21, 2007; introduction extended, version accepted for publication in J.Phys.

    Frequência e fatores associados ao atraso para o tratamento do câncer de mama no Brasil segundo dados do PAINEL-Oncologia, 2019-2020

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    Objective: To analyze the delay in treatment and the flow of care for women with breast cancer in Brazil in 2019 and 2020. Method: Follow-up study of breast cancer cases available in the Oncology Panel. To analyze the explanatory variables associated with the delay (greater than 60 days) to start treatment, a chi-square test and multilevel logistic regression were performed. Results: 22,956 cases (54.5%) were identified in 2019 and 17,722 (48.7%) in 2020 with delay in treatment. The Southeast region (54.6%) had a higher proportion of delay, which was higher when carried out outside the municipality of residence and lower in 2020 compared to 2019. residence. Conclusion: Strategies that reduce the time interval until the beginning of cancer treatment and optimize health care networks in the states should be prioritized.Objetivo: Analizar la demora en el tratamiento y el flujo de atención de mujeres con cáncer de mama en Brasil en 2019 y 2020. Método: Estudio de seguimiento de los casos de cáncer de mama disponibles en el Panel de Oncología. Para analizar las variables explicativas asociadas al retraso (mayor de 60 días) en el inicio del tratamiento se realizó la prueba de chi-cuadrado y regresión logística multinivel. Resultados: se identificaron 22.956 casos (54,5%) en 2019 y 17.722 (48,7%) en 2020 con retraso en el tratamiento. La región Sudeste (54,6%) tuvo mayor proporción de atraso, siendo mayor cuando se realiza fuera del municipio de residencia y menor en 2020 en relación a 2019. de residencia. Conclusión: Se deben priorizar estrategias que reduzcan el intervalo de tiempo hasta el inicio del tratamiento del cáncer y optimicen las redes de atención de salud en los estados.Objetivo: analisar o atraso para o tratamento e o fluxo assistencial de mulheres com câncer de mama no Brasil em 2019 e 2020. Métodos: estudo de seguimento de casos de câncer de mama disponibilizados no PAINEL-Oncologia; para analisar as variáveis explicativas associadas ao atraso (maior que 60 dias) no início do tratamento, realizou-se teste qui-quadrado e regressão logística multinível. Resultados: identificaram-se 22.956 casos (54,5%) em 2019 e 17.722 (48,7%) em 2020, com atraso para o tratamento; a região Sudeste (54,6%) teve maior proporção de atraso, que foi maior quando o tratamento foi realizado fora do município de residência, e menor em 2020, comparando-se a 2019; os fluxos externos, em sua maioria, ocorreram para as capitas das mesmas Unidades da Federação (UFs) de residência. Conclusão: estratégias que diminuam o intervalo de tempo até o início do tratamento oncológico e otimizem as redes de atenção em saúde nas UFs devem ser priorizadas

    [Access to early breast cancer diagnosis in the Brazilian Unified National Health System: an analysis of data from the Health Information System].

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    The recent reduction in breast cancer mortality in high-income countries resulted from improvements in early detection and treatment. Breast cancer is the most common cancer in Brazilian women. Since 2004, the government has recommended annual clinical breast examination for women aged ≥ 40 years and biannual mammograms for those aged 50-69. This article investigates the degree of implementation of these guidelines using data from the Brazilian Unified National Health System for 2010 according to major geographic region and age group. The findings showed low national mammogram coverage in the target population (32% in the 50-59-year group; 25% from 60 to 69 years). The percentage of women with abnormal radiological findings who underwent biopsy was also low (27% for 50-59 years; 63% for 60-69 years). The number of breast cancer surgeries exceeded the number of cases detected by mammography but was well below the estimated number of incident breast cancer cases in 2010. There are striking regional inequalities in access to early detection and surgery, being the lowest access in the North Region and the highest in the South Region

    Tendência Temporal da Cobertura de Mamografias no Sistema Único de Saúde, Brasil, 2010-2019

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    Introdução: O câncer de mama no Brasil apresenta elevadas taxas de incidência e mortalidade apesar da tendência de redução da mortalidade em algumas Regiões. Objetivo: Descrever a tendência da cobertura de mamografias de rastreamento nas Macrorregiões e Estados brasileiros e identificar a influência de Políticas Nacionais voltadas ao controle do câncer de mama entre 2010-2019. Método: Foi calculada a razão entre mamografias de rastreamento na faixa etária de 50-69 anos por local de residência e subtraída a população das residentes com plano de saúde na faixa etária e no período referidos. A tendência foi avaliada pelo modelo de regressão Joinpoint. Resultados: A cobertura aumentou no Brasil de 2010-2014 e apresentou queda de 2014-2019, com aumento na proporção de exames realizados na população-alvo. Esse padrão foi observado nas demais Regiões, exceto na Centro-Oeste, porém com ano de mudança da tendência diferente. Foram identificados dois pontos de mudança no país: de 2010-2014, com tendência crescente (APC 8,7, IC 95% 6,2; 11,3), e de 2014-2019, com tendência decrescente (APC -4,2, IC 95% -5,7; -2,7), ambos significantes. A Região Nordeste foi a única com três pontos de mudança de tendência: 2010-2012 (APC 30,3, IC 95% 22,9; 38,2), 2012-2017 (APC 4,7, IC 95% 3,0; 6,4) e 2017-2019 (APC -14,9, IC 95% -19,7; - 9,8). Não foi identificada tendência para a Região Centro-Oeste. Conclusão: Houve crescimento na proporção de mamografias de rastreamento realizadas na população-alvo no período, para Brasil e Regiões, e tendência de redução na cobertura da mamografia a partir de 2014. Esses resultados indicam priorização da população-alvo do programa nas ações de rastreamento

    Emisión acumulada de óxido nitroso (N20) en sistemas pastoriles de la Sierra Catarinense - Brasil.

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    En este trabajo se evaluaron y compararon la emisión de N2O generados por los sistemas pastoriles más empleados en Santa Catarina, Brasil.Suplemento 1. Edição do 43º Congreso Argentino de Producción Animal

    Interobserver reliability in the classification of pairs of records formed by probabilistic linkage of SISMAMA databases.

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    INTRODUCTION: The study assessed interobserver reliability in the classification of record pairs formed during probabilistic linkage of health-related databases, a key step in the methodology validation to be used in a larger on-going study on inequalities in the access to breast and cervical cancer control activities in Brazil (DAAC-SIS). METHODOLOGY: The RecLink software was used to link two databases of the Breast Cancer Control Information System (SISMAMA) in the state of Minas Gerais, Brazil: a reference database, which included 301 screening mammograms with probable benign diagnosis (BI-RADS 3 category) recorded in October 2010, and a database comprising 158,517 mammograms registered in 2011. Subsequently, the 215 pairs of records that were not assigned the maximum RecLink score were independently classified as being true or false by ten independent evaluators from four participating centers. RESULTS: The Kappa coefficient ranged from 0.87 to 1.00. Six evaluators were in perfect agreement with one or more evaluators from the other centers. The global Kappa was 0.96 (95% confidence interval - 95%CI 0.94 - 0.99). DISCUSSION: Assessment of interobserver reliability is key to ensuring the quality of the record linkage, and it should be routine practice in studies of this nature. The disclosure of such results contributes to transparency in the conduct of such studies and in the reporting of their findings. CONCLUSION: Interobserver reliability in this study was excellent, indicating satisfactory team consistency in the classification of record pairs

    Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

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    Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV
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