The Analyticity of a Generalized Ruelle's Operator

In this work we propose a generalization of the concept of Ruelle operator for one dimensional lattices used in thermodynamic formalism and ergodic optimization, which we call generalized Ruelle operator, that generalizes both the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator defined in [Bowen]. We suppose the alphabet is given by a compact metric space, and consider a general a-priori measure to define the operator. We also consider the case where the set of symbols that can follow a given symbol of the alphabet depends on such symbol, which is an extension of the original concept of transition matrices from the theory of subshifts of finite type. We prove the analyticity of the Ruelle operator and present some examples

Prognostic and clinicopathological significance of tumor-stroma ratio in head and neck squamous cell carcinoma:a systematic review

Analysis of the tumor microenvironment has been proposed as a strategy for the treatment and prognosis of different neoplastic processes. A grading system based on the tumor-stroma ratio (TSR), which evaluates the proportion of stroma in relation to neoplastic parenchyma at the invasion front, has shown a strong prognostic value in different neoplastic processes. The aim of the present systematic review was to understand the role of the TSR in head and neck squamous cell carcinoma (HNSCC), evaluating its correlation with clinical and prognostic parameters. An electronic search was performed in PubMed/Medline, Web of Science, Science Direct, Scopus, Embase, and the Cochrane Collaboration Library. Publications assessing the relationship between TSR and prognosis in cases of HNSCC were eligible. The quality of the studies was assessed independently by four evaluators using the Newcastle-Ottawa scale. After application of the previously es+lished inclusion/exclusion criteria, nine articles were included in the qualitative synthesis. With regards to quality on the Newcastle-Ottawa scale, an overall value of 4.55 was obtained. This systematic review demonstrated a strong association between TSR and prognosis in esophageal and oral squamous cell carcinomas. Histopathological analysis of the TSR can optimize the analysis of the prognosis of cases diagnosed with HNSSC. In addition, the TSR is a reliable and simple parameter that can be evaluated in hematoxylin/eosin-stained slides during routine laboratory examinations, showing high inter- and intraobserver agreement

Impact of adhesive and photoactivation method on sealant integrity and polymer network formation

We evaluated the influence of photoactivation method and hydrophobic resin (HR) application on the marginal and internal adaptation, hardness (KHN), and crosslink density (CLD) of a resin-based fissure sealant. Model fissures were created in bovine enamel fragments (n = 10) and sealed using one of the following protocols: no adhesive system + photoactivation of the sealant using continuous light (CL), no adhesive system + photoactivation of the sealant using the soft-start method (SS), HR + CL, or HR + SS. Marginal and internal gaps and KHN were assessed after storage in water for 24 h. The CLD was indirectly assessed by repeating the KHN measurement after 24 h of immersion in 100% ethanol. There was no difference among the samples with regard to marginal or internal adaptation. The KHN and CLD were similar for samples cured using either photoactivation method. Use of a hydrophobic resin prior to placement of fissure sealants and curing the sealant using the soft-start method may not provide any positive influence on integrity or crosslink density

Comparative study on the use of specific and heterologous microsatellite primers in the stingless bees Melipona rufiventris and M. mondury (Hymenoptera, Apidae)

Due to their high degree of polymorphism, microsatellites are considered useful tools for studying population genetics. Nevertheless, studies of genetic diversity in stingless bees by means of these primers have revealed a low level of polymorphism, possibly the consequence of the heterologous primers used, since in most cases these were not specifically designed for the species under consideration. Herein we compared the number of polymorphic loci and alleles per locus, as well as observed heterozygosity in Melipona rufiventris and M. mondury populations, using specific and heterologous primers. The use of specific primers placed in evidence the greater frequency of polymorphic loci and alleles per locus, besides an expressive increase in observed heterozygosity in M. rufiventris and M. mondury, thereby reinforcing the idea that populational studies should be undertaken by preferably using species-specific microsatellite primers

ACALASIA NA DOENÇA DE CHAGAS É DIFERENTE DE ACALASIA IDIOPÁTICA? EXPERIÊNCIA DO HOSPITAL DE CLÍNICAS DE PORTO ALEGRE

Objetive: The objective of this study is to evaluate the differences between achalasia in Chagas’ disease and idiopathic achalasia in patients admitted to the Hospital de Clínicas de Porto Alegre, by analyzing epidemiologic, clinic, radiologic and manometric findings.Methods: Patients referred to the Hospital de Clinicas de Porto Alegre between November 1996 and December 2001 with suspicion of achalasia, later confirmed by esophageal manometry, were included in the study. In addition to manometric and radiologic findings, patients were assessed for age, sex, symptomsand symptomatic period.Results: Among 51 patients, nine (18%) presented positive serology for Chagas’ disease and 42 (82%) presented negative serology. The latter were considered carriers of idiopathic achalasia. The mean age of patients with achalasia in Chagas’ disease was 62 ± 15 years, while the mean age in the idiopathic group was 43 ± 18 years (P < 0.02). The symptomatic period for patients with achalasia in Chagas’ disease was 74 ± 47 months, and in the idiopathic group, 49 ± 35 months (P < 0.05). Dysphagia, regurgitation, thoracic pain and weight loss, values at the lower esophageal sphincter (basal pressure, post-deglutitive relaxation pressure/duration and total length) and at the esophageal body (amplitude and duration of the post-deglutitive waves) were similar in both groups.Conclusions: The only statistically significant differences found between the two groups were age and length of the symptomatic period, significantly greater in patients with achalasia in Chagas’ disease. These data suggest a greater resistance to the symptoms in older patients.Objetivo: O presente trabalho tem como objetivo avaliar as diferenças entre a acalasia chagásica e a idiopática em pacientes do Hospital de Clínicas de Porto Alegre, através da análise de achados epidemiológicos, clínicos, radiológicos e manométricos.Métodos: Foram estudados pacientes encaminhados ao Hospital de Clínicas de Porto Alegre, entre novembro de 1996 e dezembro de 2001, com suspeita de acalasia, posteriormente, confirmada por manometria esofágica. Além das características manométricas e radiológicas, os pacientes foram avaliados quanto a idade, sexo, sintomas e tempo de evolução.Resultados: Entre 51 pacientes, nove (18%) tiveram sorologia positiva para doença de Chagas e 42 (82%) sorologia negativa. Indivíduos com sorologia negativa foram considerados portadores de acalasia idiopática. Pacientes com acalasia chagásica tinham média de idade de 62 ± 15 anos e os com idiopática 43 ± 18 anos (P < 0,02). O período de evolução dos sintomas em pacientes com acalasia chagásica foi de 74 ± 47 meses e nos idiopáticos 49 ± 35 meses (P < 0,05). Disfagia, regurgitação, dor torácica e emagrecimento, valores do esfíncter esofágico inferior (pressão basal, pressão e duração de relaxamento pós-deglutição e comprimento total) e do corpo esofágico (amplitude e duração das ondas pós-deglutição) foram similares em ambos os grupos.Conclusões: As únicas diferenças estatisticamente significativas encontradas entre os dois grupos foram a média de idade e o período de evolução dos sintomas, maiores nos pacientes chagásicos. Esses dados permitem especular sobre uma maior tolerância aos sintomas nos pacientes com idade mais avançada

Genotype by environment interaction in Nelore cattle from five Brazilian states

Records from 75,941 Nelore cattle were used to determine the importance of genotype by environment interaction (GEI) in five Brazilian states. (Co)variance components were estimated by single-trait analysis (with yearling weight, W450, considered to be the same trait in all states) and multiple-trait analysis (with the record from each state considered to be a different trait). The direct heritability estimates for yearling weight were 0.51, 0.39, 0.44, 0.37 and 0.41 in the states of Goiás, Mato Grosso, São Paulo, Mato Grosso do Sul and Minas Gerais, respectively. The across-state genetic correlation estimates between Goiás and Mato Grosso, Goiás and Minas Gerais, São Paulo and Minas Gerais, and Mato Grosso do Sul and Minas Gerais ranged from 0.67 to 0.75. These estimates indicate that GEIs are biologically important. No interactions were observed between Goiás and São Paulo, Goiás and Mato Grosso do Sul, Mato Grosso and São Paulo, Mato Grosso and Mato Grosso do Sul, Mato Grosso and Minas Gerais, or São Paulo and Mato Grosso do Sul (0.82 to 0.97). Comparison of single and multiple-trait analyses showed that selection based on the former was less efficient in the presence of GEI, with substantial losses (up to 10%) during selection