306 research outputs found
O estudo de produtos notáveis através da investigação matemática
Este artigo se propõe a abordar como o ensino de álgebra tem sido proposto pelos autores nas séries finais do Ensino Fundamental, na perspectiva da investigação Matemática, ou seja, deixando de lado a reprodução mecânica e tradicional de algoritmos. Acreditando em uma abordagem diferenciada dentro do ensino da Matemática, uma atividade investigativa referente ao caso "Quadrado da soma de dois termos" de produtos notáveis foi aplicada a alunos que concluÃram o 7º ano do Ensino Fundamental em 2017. Constatou-se que, mesmo sem conhecimentos de álgebra, os alunos conseguiram, por meio da observação, chegar ao algoritmo de uma forma mais significativa, sem recorrer a fórmulas prontas e memorizadas
Integration of Data Mining Classification Techniques and Ensemble Learning for Predicting the Type of Breast Cancer Recurrence
Conservative surgery plus radiotherapy is an alternative to radical mastectomy in the early stages of breast cancer, presenting equivalent survival rates. Data mining facilitates to manage the data and provide the useful medical progression and treatment of cancerous conditions as these methods can help to reduce the number of false positive and false negative decisions. Various machine learning techniques can be used to support the doctors in effective and accurate decision making. In this paper, various classifiers have been tested for the prediction of type of breast cancer recurrence and the results show that neural networks outperform others
High expression of Lewis(y/b )antigens is associated with decreased survival in lymph node negative breast carcinomas
INTRODUCTION: There is sufficient evidence that blood group related Lewis antigens are tumour-associated molecules. The Lewis(y )and Lewis(b )antigens are complex carbohydrates that are over-expressed by breast, lung, colon and ovarian cancers. The SC101 mAb is a unique Lewis(y/b )binding antibody that binds to native and extended Lewis(y )and Lewis(b )haptens, displaying no cross reactivity with H type 1, H type 2, Lewis(x )or normal blood group antigens. METHODS: Immunohistochemical detection of Lewis(y/b )was performed on 660 formalin-fixed, paraffin embedded breast tumour specimens using a streptavidin-biotin peroxidase technique. Tissue from these patients had previously been included in tissue microarrays. This cohort comprises a well characterized series of patients with primary operable breast cancer diagnosed between 1987 and 1992, obtained from the Nottingham Tenovus Primary Breast Carcinoma Series. This includes patients 70 years of age or less, with a mean follow up of 7 years. RESULTS: Of the breast carcinomas, 370 of 660 (56%) were negative for Lewis(y/b )expression, 110 (17%) cases showed a low level of expression (<25% of positive cells) and only 54 cases (8%) showed extensive expression of Lewis(y/b )(>75% of positive cells). We found significant positive associations between histological grade (p < 0.001), Nottingham Prognostic Index (p = 0.016), tumour type (p = 0.007) and the level of Lewis (y/b )expression. There was a significant correlation between the proportion of Lewis(y/b )positive tumour cells and survival in lymph-node negative patients (p = 0.006). CONCLUSION: The unique epitope recognised by SC101 mAb on Lewis(y/b )hapten is over-expressed on breast tumour tissue compared with normal breast. In this large series of invasive breast cancers, higher expression of Lewis(y/b )was more often found in high grade and poor prognosis tumours compared to good prognosis cancers. Moreover, in lymph node negative breast carcinomas, over-expression of Lewis(y/b )hapten was associated with significantly decreased patient survival
Vulnerability of Brazilian municipalities to hantavirus infections based on multi‑criteria decision analysis
Background: Hantavirus infection is an emerging zoonosis transmitted by wild rodents. In Brazil, high case-fatality rates among humans infected with hantavirus are of serious concern to public health authorities. Appropriate preventive measures partly depend on reliable knowledge about the geographical distribution of this disease. Methods: Incidence of hantavirus infections in Brazil (1993–2013) was analyzed. Epidemiological, socioeconomic, and demographic indicators were also used to classify cities’ vulnerability to disease by means of multi-criteria decision analysis (MCDA). Results: From 1993 to 2013, 1752 cases of hantavirus were registered in 16 Brazilian states. The highest incidence of hantavirus was observed in the states of Mato Grosso (0.57/100,000) and Santa Catarina (0.13/100,000). Based on MCDA analysis, municipalities in the southern, southeastern, and midwestern regions of Brazil can be classified as highly vulnerable. Most municipalities in northern and northeastern Brazil were classified as having low vulnerability to hantavirus cardiopulmonary syndrome. Conclusions: Although most human infections by hantavirus registered in Brazil occurred in the southern region of the country, a greater vulnerability to hantavirus was found in the Brazilian Midwest. This result reflects the need to strengthen surveillance where the disease has thus far gone unreported
Numerical modeling of the thermal contact in metal forming processes
Heat flow across the interface of solid bodies in
contact is an important aspect in several engineering applications.
This work presents a finite element model for the
analysis of thermal contact, which takes into account the
effect of contact pressure and gap dimension in the heat
flow across the interface between two bodies. Additionally,
the frictional heat generation is also addressed, which
is dictated by the contact forces predicted by the mechanical
problem. The frictional contact problem and thermal
problem are formulated in the frame of the finite element
method. A new law is proposed to define the interfacial heat
transfer coefficient (IHTC) as a function of the contact pressure
and gap distance, enabling a smooth transition between
two contact status (gap and contact). The staggered scheme
used as coupling strategy to solve the thermomechanical
problem is briefly presented. Four numerical examples are presented to validate the finite element model and highlight
the importance of the proposed law on the predicted
temperature.The authors gratefully acknowledge the financial
support of the Portuguese Foundation for Science and Technology
(FCT) under the project PTDC/EMS-TEC/1805/2012 and by
FEDER funds through the program COMPETE Programa Operacional
Factores de Competitividade, under the project CENTRO-07-0224-
FEDER-002001 (MT4MOBI). The second author is also grateful to the
FCT for the postdoctoral grant SFRH/BPD/101334/2014. The authors
would like to thank Prof. A. Andrade-Campos for helpful contributions
on the development of the finite element code presented in this work.info:eu-repo/semantics/publishedVersio
Family History and Breast Cancer Hormone Receptor Status in a Spanish Cohort
Breast cancer is a heterogenous disease that impacts racial/ethnic groups differently. Differences in genetic composition, lifestyles, reproductive factors, or environmental exposures may contribute to the differential presentation of breast cancer among Hispanic women.A population-based study was conducted in the city of Santiago de Compostela, Spain. A total of 645 women diagnosed with operable invasive breast cancer between 1992 and 2005 participated in the study. Data on demographics, breast cancer risk factors, and clinico-pathological characteristics of the tumors were collected. Hormone receptor negative tumors were compared with hormone receptor postive tumors on their clinico-pathological characteristics as well as risk factor profiles.Among the 645 breast cancer patients, 78% were estrogen receptor-positive (ER+) or progesterone receptor-positive (PR+), and 22% were ER−&PR−. Women with a family history of breast cancer were more likely to have ER−&PR− tumors than women without a family history (Odds ratio, 1.43; 95% confidence interval, 0.91–2.26). This association was limited to cancers diagnosed before age 50 (Odds ratio, 2.79; 95% confidence interval, 1.34–5.81).An increased proportion of ER−&PR− breast cancer was observed among younger Spanish women with a family history of the disease
Estudo das habilidades auditivas de resolução temporal e figura-fundo em dançarinos
Resumo:OBJETIVO:avaliar a habilidade auditiva de resolução temporal e de identificação de sentenças com mensagem competitiva em dançarinos.MÉTODOS:trata-se de um estudo prospectivo em que foram avaliados 40 indivÃduos distribuÃdos em dois grupos: grupo 1 (dançarinos) e grupo 2 (não-dançarinos). Os instrumentos de avaliação do processamento auditivo utilizados foram: teste Gaps-in-noise (GIN) e teste de reconhecimento de sentenças na presença de mensagem competitiva (SSI).RESULTADOS:os limiares de gap de ambos os grupos variaram de 3 a 6 ms e não demostraram diferença estatisticamente significante na comparação entre os grupos. Houve diferença estatisticamente significante ao comparar a porcentagem de identificação de gaps entre os dois grupos, sendo que o grupo de dançarinos apresentou média maior que o grupo de não dançarinos.O teste de reconhecimento de frases em escuta monótica (rel -10dB) mostrou resultados que variaram de 50% até 100% para o grupo de dançarinos e de 40% até 100% para o de não - dançarinos. A idade de inÃcio da dança (antes ou depois dos sete anos) não influenciou no desempenho dos testes estudados. Não houve correlação entre as variáveis dos achados obtidos nos testes estudados no grupo de dançarinos considerando o tempo de dança.CONCLUSÃO:a dança influenciou positivamente a habilidade auditiva de resolução temporal, pois o grupo de dançarinos apresentou desempenho melhor do que o grupo de não-dançarinos. A dança parece não ter influenciado a habilidade auditiva de figura-fundo
Breast cancer prognostic classification in the molecular era: the role of histological grade
Breast cancer is a heterogeneous disease with varied morphological appearances, molecular features, behavior, and response to therapy. Current routine clinical management of breast cancer relies on the availability of robust clinical and pathological prognostic and predictive factors to support clinical and patient decision making in which potentially suitable treatment options are increasingly available. One of the best-established prognostic factors in breast cancer is histological grade, which represents the morphological assessment of tumor biological characteristics and has been shown to be able to generate important information related to the clinical behavior of breast cancers. Genome-wide microarray-based expression profiling studies have unraveled several characteristics of breast cancer biology and have provided further evidence that the biological features captured by histological grade are important in determining tumor behavior. Also, expression profiling studies have generated clinically useful data that have significantly improved our understanding of the biology of breast cancer, and these studies are undergoing evaluation as improved prognostic and predictive tools in clinical practice. Clinical acceptance of these molecular assays will require them to be more than expensive surrogates of established traditional factors such as histological grade. It is essential that they provide additional prognostic or predictive information above and beyond that offered by current parameters. Here, we present an analysis of the validity of histological grade as a prognostic factor and a consensus view on the significance of histological grade and its role in breast cancer classification and staging systems in this era of emerging clinical use of molecular classifiers. © 2010 BioMed Central Lt
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