Crisp sets as classes of discontinuous fuzzy sets

AbstractThis paper aims to show how, by using a threshold-based approach, a path from imprecise information to a crisp ‘decision’ can be developed. It deals with the problem of the logical transformation of a fuzzy set into a crisp set. Such threshold arises from the ideas of contradiction and separation, and allows us to prove that crisp sets can be structurally considered as classes of discontinuous fuzzy sets. It is also shown that continuous fuzzy sets are computationally indistinguishable from some kind of discontinuous fuzzy sets

Efeito da fertilização mineral e orgânica e do uso de misturas simples e complexas de sementes na instalação de pastagens anuais ricas em leguminosas

No âmbito de um estudo de longo prazo de pastagens permanentes semeadas ricas em leguminosas estudou-se o efeito dos seguintes factores na flora pascícola de primeiro ano: 1) pastagem – mistura simples (MSIMP), mistura comercial complexa rica em leguminosas (MCOMP) e vegetação espontânea (ABAND); 2) fertilização de fundo – estrume de bovino (EST: 40 t/ha), fertilização mineral (FERT: 1000 kg calcário/ha, 53 kg P2O5/ha e 30 kg K2O /ha) e sem fertilização. Os dados experimentais revelaram: a percentagem de cobertura das plantas indígenas foi francamente mais elevada do que o das plantas semeadas; o tratamento ABAND foi o único que demonstrou um controlo significativo na estruturação dos dados florísticos numa RDA (Análise de redundância); FERT teve um efeito mais favorável do que EST na flora adventícia regional de cereais que colonizou as parcelas experimentais; as leguminosas semeadas – com 35,0% (EST) e 15,3% (FERT) de cobertura – foram beneficiadas pela aplicação de estrumes à sementeira; os estrumes provavelmente tiveram um efeito favorável no desenvolvimento de nichos de regeneração adequados às leguminosas, sobretudo num ano agrícola tão seco como foi o de 2008-2009; a percentagem de cobertura do L. perenne foi semelhante nos três tipos de fertilização; o tipo de mistura de sementes (MSIMP e MCOMP) teve um efeito irrelevante na flora pratense semeada.FCT-Fundação Para a Ciência e Tecnologia

Sistemas de recompensa: Uma analise empírica de antecedentes e consequências

O objectivo principal deste estudo consistiu em analisar os antecedentes e consequências da configuração do sistema de recompensas. O trabalho avaliou a influência da cultura dominante de uma organização nas características do sistema de recompensas, bem como os efeitos deste no desempenho dos sujeitos. A questão de partida era: qual o contributo da configuração do sistema de recompensas de uma organização para a explicação do nível do desempenho dos seus trabalhadores? Este problema de investigação pode por sua vez subdividir-se nas seguintes questões: que dimensões da cultura organizacional influenciam a configuração do sistema de remuneração? Quais os efeitos do sistema de recompensas de uma organização no desempenhodos seus trabalhadores?Os resultados sugerem que as características do sistema de recompensas de uma organização sofrem influências da cultura organizacional dominante, no que se refere nomeadamente ao nível da orientação competitiva ou orientação humanista. A cultura dominante e o nível de remuneração influem de forma significativa na percepção de equidade, ou seja, organizações com cultura orientada para a competição geram percepções de iniquidade enquanto que organizações de matiz cooperativo promovem percepções de equidade. Por último, as características do sistema de recompensas influenciam múltiplas dimensões do desempenho organizacional

Sistemas de recompensa: Uma analise empírica de antecedentes e consequências

O objectivo principal deste estudo consistiu em analisar os antecedentes e consequências da configuração do sistema de recompensas. O trabalho avaliou a influência da cultura dominante de uma organização nas características do sistema de recompensas, bem como os efeitos deste no desempenho dos sujeitos. A questão de partida era: qual o contributo da configuração do sistema de recompensas de uma organização para a explicação do nível do desempenho dos seus trabalhadores? Este problema de investigação pode por sua vez subdividir-se nas seguintes questões: que dimensões da cultura organizacional influenciam a configuração do sistema de remuneração? Quais os efeitos do sistema de recompensas de uma organização no desempenho dos seus trabalhadores? Os resultados sugerem que as características do sistema de recompensas de uma organização sofrem influências da cultura organizacional dominante, no que se refere nomeadamente ao nível da orientação competitiva ou orientação humanista. A cultura dominante e o nível de remuneração influem de forma significativa na percepção de equidade, ou seja, organizações com cultura orientada para a competição geram percepções de iniquidade enquanto que organizações de matiz cooperativo promovem percepções de equidade. Por último, as características do sistema de recompensas influenciam múltiplas dimensões do desempenho organizacional.ABSTRACT: This study analyzed some antecedents and consequences of an organization’s reward system. The study evaluated the influence of the dominant culture on the characteristics of the reward system, as well as the effects of this system on organizational behavior. The departing question was: what is the contribution of the reward system to the explanation of behavior in organizations? This research problem was subdivided in the following questions: what dimensions of the culture organizational do influence the compensation system? What are the effects of the reward system? Results suggest that the characteristics of rewards are influenced by the dominant cultural type, operationalized as competitive and humanist orientations. Culture and reward systems influence the perception of fairness, in the sense that organizations with competitive cultures tend to generate more perceptions of inequity, while cooperative organizations promote perceptions of equity.info:eu-repo/semantics/publishedVersio

A common missense variant in BRCA2 predisposes to early onset breast cancer

INTRODUCTION: Mutations in the BRCA2 gene are one of the two major causes of hereditary breast cancer. Protein-truncating mutations of BRCA2 are usually deleterious and increase the risk of breast cancer up to 80% over a lifetime. A few missense mutations in BRCA2 are believed to have a similarly high penetrance, apart from more common neutral polymorphisms. It is often difficult to classify a particular sequence variant as a mutation or a polymorphism. For a deleterious variant, one would expect a greater allele frequency in breast cancer cases than in ethnic-matched controls. In contrast, neutral polymorphic variants should be equally frequent in the two groups. METHODS: We genotyped 3,241 cases of breast cancer diagnosed at under 51 years of age, unselected for family history, from 18 hospitals throughout Poland and 2,791 ethnic-matched controls for a single BRCA2 C5972T variant. RESULTS: The variant was present in approximately 6% of the Polish population. In the study, 13 women (11 cases and two controls (OR = 4.7; p = 0.02)) were homozygous for the variant allele. The overall odds ratio for breast cancer in women with a single copy of the BRCA2 C5972T variant was 1.1 (p = 0.7); however, the effect was significant for patients diagnosed at or before age 40 (OR = 1.4; p = 0.04). We reviewed the association between the BRCA2 variant in different histologic subgroups and found the effect most pronounced in women who had ductal carcinoma in situ (DCIS) with micro-invasion (OR = 2.8; p < 0.0001). CONCLUSION: The BRCA2 C5972T allele is a common variant in Poland that increases the risk of DCIS with micro-invasion. The homozygous state is rare but increases the risk of breast cancer five-fold

Immunization in pregnancy clinical research in low- and middle-income countries - Study design, regulatory and safety considerations.

Immunization of pregnant women is a promising public health strategy to reduce morbidity and mortality among both the mothers and their infants. Establishing safety and efficacy of vaccines generally uses a hybrid design between a conventional interventional study and an observational study that requires enrolling thousands of study participants to detect an unknown number of uncommon events. Historically, enrollment of pregnant women in clinical research studies encountered many barriers based on risk aversion, lack of knowledge, and regulatory ambiguity. Conducting research enrolling pregnant women in low- and middle-income countries can have additional factors to address such as limited availability of baseline epidemiologic data on disease burden and maternal and neonatal outcomes during and after pregnancy; challenges in recruiting and retaining pregnant women in research studies, variability in applying and interpreting assessment methods, and variability in locally acceptable and available infrastructure. Some measures to address these challenges include adjustment of study design, tailoring recruitment, consent process, retention strategies, operational and logistical processes, and the use of definitions and data collection methods that will align with efforts globally

Lympho-vascular invasion in BRCA related breast cancer compared to sporadic controls

<p>Abstract</p> <p>Background</p> <p>Germline mutations in the BRCA1 gene predispose to the development of breast cancer, exhibiting a specific histological phenotype. Identification of possible hallmarks of these tumors is important for selecting patients for genetic screening and provides inside in carcinogenetic pathways.</p> <p>Since BRCA1-associated breast cancers have pushing borders that prevent them from easily reaching vessels and are often of the medullary (like) type that is known to have a low rate of lympho-vascular invasion (LVI), we hypothesized that absence of LVI could characterize BRCA1 related breast cancer.</p> <p>Methods</p> <p>A population of 68 BRCA1 related invasive breast cancers was evaluated for LVI by an experienced breast pathologist blinded to mutation status, and compared to a control group matched for age, grade and tumor type.</p> <p>Results</p> <p>LVI was present in 25.0% of BRCA1 related cases, compared to 20.6% of controls (P = 0.54, OR = 1.29, CI 0.58-2.78).</p> <p>Conclusion</p> <p>LVI is frequent in BRCA1 germline mutation related breast cancers, but seems to occur as often in sporadic controls matched for age, grade and tumor type. Apparently, these hereditary cancers find their way to the blood and lymph vessels despite their well demarcation and often medullary differentiation.</p

Expression of the stem cell marker ALDH1 in BRCA1 related breast cancer

Introduction The BRCA1 protein makes mammary stem cells differentiate into mature luminal and myoepithelial cells. If a BRCA1 mutation results in a differentiation block, an enlarged stem cell component might be present in the benign tissue of BRCA1 mutation carriers, and these mammary stem cells could be the origin of BRCA1 related breast cancer. Since ALDH1 is a marker of both mammary stem cells and breast cancer stem cells, we compared ALDH1 expression in malignant tissue of BRCA1 mutation carriers to non-carriers. Methods Forty-one BRCA1 related breast cancers and 41 age-matched sporadic breast cancers were immunohistochemically stained for ALDH1. Expression in epithelium and stroma was scored and compared. Results Epithelial (P=0.001) and peritumoral (P=0.001) ALDH1 expression was significantly higher in invasive BRCA1 related carcinomas compared to sporadic carcinomas. Intratumoral stromal ALDH1 expression was similarly high in both groups. ALDH1 tumor cell expression was an independent predictor of BRCA1 mutation status. Conclusion BRCA1 related breast cancers showed significantly more frequent epithelial ALDH1 expression, indicating that these hereditary tumors have an enlarged cancer stem cell component. Besides, (peritumoral) stromal ALDH1 expression was also more frequent in BRCA1 mutation carriers. ALDH1 may therefore be a diagnostic marker and a therapeutic target of BRCA1 related breast cancer