Model to predict the chloride penetration in concrete with profile forming peak: verification of its precision

Chloride attack in marine environments or in structures where deicing salts are used will not always show profiles with concentrations that decrease from the external surface to the interior of the concrete. Some profiles show an increase in chloride concentrations from when a peak is formed. This type of profile must be analyzed in a different way from the traditional model of Fick`s second law to generate more precise service life models. A model for forecasting the penetration of chloride ions as a function of time for profiles having formed a peak. To confirm the efficiency of this model, it is necessary to observe the behavior of a chloride profile with peak in a specific structure over a period of time. To achieve this, two chloride profiles with different ages (22 and 27 years) were extracted from the same structure. The profile obtained from the 22-year sample was used to estimate the chloride profile at 27 years using three models: a) the traditional model using Fick`s second law and extrapolating the value of C(S)-external surface chloride concentration; b) the traditional model using Fick`s second law and shifting the x-axis to the peak depth; c) the previously proposed model. The results from these models were compared with the actual profile measured in the 27-year sample and the results were analyzed. The model was presented with good precision for this study of case, requiring to be tested with other structures in use.

The generalized log-gamma mixture model with covariates: local influence and residual analysis

In a sample of censored survival times, the presence of an immune proportion of individuals who are not subject to death, failure or relapse, may be indicated by a relatively high number of individuals with large censored survival times. In this paper the generalized log-gamma model is modified for the possibility that long-term survivors may be present in the data. The model attempts to separately estimate the effects of covariates on the surviving fraction, that is, the proportion of the population for which the event never occurs. The logistic function is used for the regression model of the surviving fraction. Inference for the model parameters is considered via maximum likelihood. Some influence methods, such as the local influence and total local influence of an individual are derived, analyzed and discussed. Finally, a data set from the medical area is analyzed under the log-gamma generalized mixture model. A residual analysis is performed in order to select an appropriate model.

Erectile Dysfunction and Correlated Factors in Brazilian Men Aged 18-40 years

Introduction. Few population-based studies in erectile dysfunction (ED) included subjects less than 40 years old and analyzed the several factors and consequences potentially associated with this condition. Aim. Evaluation of the prevalence of erectile dysfunction (ED) and associated factors in a sample of Brazilian men aged 18 to 40 years old. Methods. Cross-sectional study in which subjects were contacted in public places of 18 major Brazilian cities and interviewed using an anonymous questionnaire. Survey data were submitted to chi-squared, student`s t-test and logistic regression analyses. Main Outcome Measures. The data were collected by means of a self-administered questionnaire with 87 questions about sociodemographic variables, general health, habits and lifestyle-related factors, sexual behavior and sexual difficulties, including ED which was assessed by a single question. Results. Prevalence of ED in 1,947 men was 35.0% (73.7% mild, 26.3% moderate/complete). Greater frequency of ED was seen in subjects that never had information about sex, experienced difficulties in the beginning of sexual life and have never masturbated. ED was associated to lower level of education, but not to race, sexual orientation, employment or marital status. Also, no association was found between ED and smoking, alcoholism, obesity, sedentary life, diabetes, hypertension, cardiovascular disease, hyperlipidemia, depression or anxiety. ED caused negative impact in men`s self-esteem, interpersonal relationships, work and leisure activities, and in sexual life satisfaction. Less than 10% of men with ED had received medical treatment for this problem. Conclusions. Prevalence of ED in this young population was high, mostly of mild severity. Low education and psychosocial problems were associated to ED and, due probably to the sample subjects` young age, no association was found with organic problems. Measures in the fields of education and psychosocial difficulties prevention would have a positive impact in the control of erectile dysfunction in the young population. Martins FG, and Abdo CHN. Erectile dysfunction and correlated factors in Brazilian men aged 18-40 years. J Sex Med 2010;7:2166-2173.

Sexual satisfaction among patients with erectile dysfunction treated with counseling, sildenafil, or both

Introduction. Sexual satisfaction is linked to life satisfaction, and erectile dysfunction (ED) may lead to an impaired quality of life (QOL). Aim. Our goal was to evaluate the QOL among Brazilian patients with ED, before and after three kinds of treatment. Methods. Men aged 25-55 years, with a diagnosis of psychogenic or mixed ED, according to the Classification of Mental and Behavioral Disorders of the International Classification of Diseases, 10th edition, and the Standard Practice in Sexual Medicine, were randomly assigned to three treatment groups: counseling, sildenafil, and sildenafil plus counseling. At baseline each group had 40 patients. Sildenafil was provided in 50 mg that could be adjusted to 100 mg. The patients could initially take one to two tablets per week and the entire treatment lasted for 3 months. Counseling was provided in group sessions that took place once a week. They were evaluated at baseline and after 3 months of treatment with the Male Sexual Quotient (MSQ) and the Sexual Health Inventory for Men (SHIM). Main Outcome Measures. The correlation between the patients` MSQ score and scores on the SHIM. Results. One hundred seventeen patients were enrolled. The three groups were similar according to age, marital status, mean time of ED, and ED severity and etiology. At baseline, MSQ and SHIM total scores were not different among the three groups. MSQ scores increased from 41.2 +/- 15.3, 38.7 +/- 18.0, and 46.8 +/- 17.0 to 48.5 +/- 15.3, 63.8 +/- 21.6, and 70.0 +/- 17.3 after counseling, sildenafil, and sildenafil plus counseling, respectively (P < 0.05). SHIM scores also increased significantly (9.6 +/- 4.1, 9.7 +/- 4.1, and 10.2 +/- 3.9 to 12.1 +/- 3.9, 16.7 +/- 5.6, and 17.7 +/- 4.5 after counseling, sildenafil, and sildenafil plus counseling, respectively) (P < 0.05). There were no serious adverse events related to sildenafil, and no patient was withdrawn from the study because of an adverse event. Conclusions. The three treatments were significantly efficient, and the best treatment was sildenafil associated with counseling.

Prediction in Multilevel Logistic Regression

The purpose of this article is to present a new method to predict the response variable of an observation in a new cluster for a multilevel logistic regression. The central idea is based on the empirical best estimator for the random effect. Two estimation methods for multilevel model are compared: penalized quasi-likelihood and Gauss-Hermite quadrature. The performance measures for the prediction of the probability for a new cluster observation of the multilevel logistic model in comparison with the usual logistic model are examined through simulations and an application.

Treadmill exercise testing of asymptomatic men and women without evidence of heart disease

The aim of this study was to test the hypothesis of differences in performance including differences in ST-T wave changes between healthy men and women submitted to an exercise stress test. Two hundred (45.4%) men and 241 (54.6%) women (mean age: 38.7 ± 11.0 years) were submitted to an exercise stress test. Physiologic and electrocardiographic variables were compared by the Student t-test and the chi-square test. To test the hypothesis of differences in ST-segment changes, data were ranked with functional models based on weighted least squares. To evaluate the influence of gender and age on the diagnosis of ST-segment abnormality, a logistic model was adjusted; P < 0.05 was considered to be significant. Rate-pressure product, duration of exercise and estimated functional capacity were higher in men (P < 0.05). Sixteen (6.7%) women and 9 (4.5%) men demonstrated ST-segment upslope ≥0.15 mV or downslope ≥0.10 mV; the difference was not statistically significant. Age increase of one year added 4% to the chance of upsloping of segment ST ≥0.15 mV or downsloping of segment ST ≥0.1 mV (P = 0.03; risk ratio = 1.040, 95% confidence interval (CI) = 1.002-1.080). Heart rate recovery was higher in women (P < 0.05). The chance of women showing an increase of systolic blood pressure ≤30 mmHg was 85% higher (P = 0.01; risk ratio = 1.85, 95%CI = 1.1-3.05). No significant difference in the frequency of ST-T wave changes was observed between men and women. Other differences may be related to different physical conditioning.

Dignified death: Concept development involving nurses and doctors in Pediatric Intensive Care Units

The aim of this study was to develop the concept of the dignified death of children in Brazilian pediatric intensive care units (PICUs). The Hybrid Model for Concept Development was used to develop a conceptual structure of dignified death in PICUs in an attempt to define the concept. The fieldwork study was carried out by means of in-depth interviews with nine nurses and seven physicians working in PICUs. Not unexpectedly, the concept of dignified death was found to be a complex phenomenon involving aspects related to decisions made by the multidisciplinary team as well as those related to care of the child and the family. Knowledge of the concept`s dimensions can promote reflection on the part of healthcare professionals regarding the values and beliefs underlying their conduct in end-of-life situations. Our hope is that this study may contribute to theoretic and methodological development in the area of end-of-life care.

Annual and polyetic progression of citrus canker on trees protected with copper sprays

The effects of copper sprays on annual and polyetic progress of citrus canker, caused by Xanthomonas citri subsp. citri, in the presence of the Asian citrus leafminer (Phyllocnistis citrella), were evaluated in a study conducted in a commercial orchard in northwest Parana state, Brazil, where citrus canker is endemic. Nonlinear monomolecular, logistic and Gompertz models were fitted to monthly disease incidence data (proportion of leaves with symptoms) for each treatment for three seasons. The logistic model provided the best estimate of disease progress for all years and treatments evaluated and logistic parameter estimates were used to describe polyetic disease dynamics. Although citrus canker incidence increased during each of the seasons studied, it decreased over the whole study period, more so in copper-treated trees than in water-sprayed controls. Copper treatment reduced disease incidence compared with controls in every year, especially 2004-2005, when incidence was ca. 10-fold higher in controls than in treated plots (estimated asymptote values 0 center dot 82 and 0 center dot 07, respectively). Copper treatment also reduced estimated initial disease incidence and epidemic growth rates every year.

Comparison of Quantitative T-Wave Alternans Profiles of Healthy Subjects and ICD Patients

Background: Current relevance of T-wave alternans is based on its association with electrical disorder and elevated cardiac risk. Quantitative reports would improve understanding on TWA augmentation mechanisms during mental stress or prior to tachyarrhythmias. However, little information is available about quantitative TWA values in clinical populations. This study aims to create and compare TWA profiles of healthy subjects and ICD patients, evaluated on treadmill stress protocols. Methods: Apparently healthy subjects, not in use of any medication were recruited. All eligible ICD patients were capable of performing an attenuated stress test. TWA analysis was performed during a 15-lead treadmill test. The derived comparative profile consisted of TWA amplitude and its associated heart rate, at rest (baseline) and at peak TWA value. Chi-square or Mann-Whitney tests were used with p values <= 0.05. Discriminatory performance was evaluated by a binary logistic regression model. Results: 31 healthy subjects (8F, 23M) and 32 ICD patients (10F, 22M) were different on baseline TWA (1 +/- 2 mu V; 8 +/- 9 mu V; p < 0.001) and peak TWA values (26 +/- 13 mu V; 37 +/- 20 mu V; p = 0,009) as well as on baseline TWA heart rate (79 +/- 10 bpm; 67 +/- 15 bpm; p < 0.001) and peak TWA heart rate (118 +/- 8 bpm; 90 +/- 17 bpm; p < 0.001). The logistic model yielded sensitivity and specificity values of 88.9% and 92.9%, respectively. Conclusions: Healthy subjects and ICD patients have distinct TWA profiles. The new TWA profile representation (in amplitude-heart rate pairs) may help comparison among different research protocols. Ann Noninvasive Electrocardiol 2009;14(2):108-118.

Self-rated oral health and associated factors in Brazilian elders

Objective: Self-rating provides a simple direct way of capturing perceptions of health. The objective of this study was to estimate the prevalence and associated factors of poor self-rated oral health among elders. Methods: National data from a cross-sectional population-based study with a multistage random sample of 4786 Brazilian older adults (aged 65-74) in 250 towns were analysed. Data collection included oral examinations (WHO 1997) and struct-ured interviews at elderly households. The outcome was measured by a single five-point-response-scale question dichotomized into `poor` (fair/poor/very poor) and `good` (good/very good) self-rated oral health. Data analyses used Poisson regression models stratified by sex. Results: The prevalence of poor self-rated oral health was 46.6% (95% CI: 45.2-48%) in the whole sample, 50.3% (48-52.5) in men and 44.2% (42.4-46) in women. Higher prevalence ratios (PR) were found in elders reporting unfavourable dental appearance (PR = 2.31; 95% CI: 2.02-2.65), poor chewing ability (PR = 1.64; CI: 1.48-1.8) and dental pain (PR = 1.44; CI: 1.04-1.23) in adjusted analysis. Poor self-perception was also associated with being men, black, unfavourable socioeconomic circumstances, unfavourable clinical oral health and with not using or needing a dental prosthesis. Conclusion: Assessment and understanding of self-rated oral health should take into account social factors, subjective and clinical oral symptoms.

Coupled reliability and boundary element model for probabilistic fatigue life assessment in mixed mode crack propagation

Fatigue and crack propagation are phenomena affected by high uncertainties, where deterministic methods fail to predict accurately the structural life. The present work aims at coupling reliability analysis with boundary element method. The latter has been recognized as an accurate and efficient numerical technique to deal with mixed mode propagation, which is very interesting for reliability analysis. The coupled procedure allows us to consider uncertainties during the crack growth process. In addition, it computes the probability of fatigue failure for complex structural geometry and loading. Two coupling procedures are considered: direct coupling of reliability and mechanical solvers and indirect coupling by the response surface method. Numerical applications show the performance of the proposed models in lifetime assessment under uncertainties, where the direct method has shown faster convergence than response surface method. (C) 2010 Elsevier Ltd. All rights reserved.

A practical approach to assess depression risk and to guide risk reduction strategies in later life

Background: Many factors have been associated with the onset and maintenance of depressive symptoms in later life, although this knowledge is yet to be translated into significant health gains for the population. This study gathered information about common modifiable and non-modifiable risk factors for depression with the aim of developing a practical probabilistic model of depression that can be used to guide risk reduction strategies. \Methods: A cross-sectional study was undertaken of 20,677 community-dwelling Australians aged 60 years or over in contact with their general practitioner during the preceding 12 months. Prevalent depression (minor or major) according to the Patient Health Questionnaire (PHQ-9) assessment was the main outcome of interest. Other measured exposures included self-reported age, gender, education, loss of mother or father before age 15 years, physical or sexual abuse before age 15 years, marital status, financial stress, social support, smoking and alcohol use, physical activity, obesity, diabetes, hypertension, and prevalent cardiovascular diseases, chronic respiratory diseases and cancer. Results: The mean age of participants was 71.7 +/- 7.6 years and 57.9% were women. Depression was present in 1665 (8.0%) of our subjects. Multivariate logistic regression showed depression was independently associated with age older than 75 years, childhood adverse experiences, adverse lifestyle practices (smoking, risk alcohol use, physical inactivity), intermediate health hazards (obesity, diabetes and hypertension), comorbid medical conditions (clinical history of coronary heart disease, stroke, asthma, chronic obstructive pulmonary disease, emphysema or cancers), and social or financial strain. We stratified the exposures to build a matrix that showed that the probability of depression increased progressively with the accumulation of risk factors, from less than 3% for those with no adverse factors to more than 80% for people reporting the maximum number of risk factors. Conclusions: Our probabilistic matrix can be used to estimate depression risk and to guide the introduction of risk reduction strategies. Future studies should now aim to clarify whether interventions designed to mitigate the impact of risk factors can change the prevalence and incidence of depression in later life.

Quality of life before surgery is a predictive factor for satisfaction among patients undergoing sympathectomy to treat hyperhidrosis

Purpose: The objective of this study was to evaluate the postoperative quality of life (QOL) experienced among a group of 1167 patients who underwent video-assisted thoracoscopic sympathectomy (VATS) to treat primary hyperhidrosis, as compared with the presurgical QOL. Methods: Between February 2002 and June 2007, 1167 patients who had undergone VATS were surveyed. The majority had presented with palmar hyperhidrosis (794 patients; 68%), while 340 (29%) had presented with axillary hyperhidrosis. Based on data obtained from the QOL protocol applied to all of the patients preoperatively, the patients were divided into two groups according to the level of their QOL: group 1 consisted of 312 patients (27%) with poor QOL and group 2 of 855 patients (73%) with very poor QOL. The same protocol was applied postoperatively, and five different levels of satisfaction were obtained. The same parameters were evaluated for both the palmar and the axillary hyperhidrosis subgroups. Results: The patients with very poor QOL had much better results in terms of improvement in QOL than did those with poor QOL ( P < .05). The same result was observed for both the palmar and. axillary hyperhidrosis subgroups (P < .05). Conclusion: The worse the preoperative QOL among patients undergoing sympathectomy to treat primary hyperhidrosis is, the better the postoperative improvement in QOL will be. (J Vase Surg 2010;51:1190-4.)

Metastatic melanoma positively influences pregnancy outcome in a mouse model: could a deadly tumor support embryo life?

The incidence of melanoma is increasing worldwide. It is one of the leading cancers in pregnancy and the most common malignancy to metastasize to placenta and fetus. There are no publications about experimental models of melanoma and pregnancy. We propose a new experimental murine model to study the effects of melanoma on pregnancy and its metastatic process. We tested several doses of melanoma cells until we arrived at the optimal dose, which produced tumor growth and allowed animal survival to the end of pregnancy. Two control groups were used: control (C) and stress control (SC) and three different routes of inoculation: intravenous (IV), intraperitoneal (IP) and subcutaneous (SC). All the fetuses and placentas were examined macroscopically and microscopically. The results suggest that melanoma is a risk factor for intrauterine growth restriction but does not affect placental weight. When inoculated by the SC route, the tumor grew only in the site of implantation. The IP route produced peritoneal tumoral growth and also ovarian and uterine metastases in 60% of the cases. The IV route produced pulmonary tumors. No placental or fetal metastases were obtained, regardless of the inoculation route. The injection of melanoma cells by any route did not increase the rate of fetal resorptions. Surprisingly, animals in the IV groups had no resorptions and a significantly higher number of fetuses. This finding may indicate that tumoral factors released in the host organism to favor tumor survival may also have a pro-gestational action and consequently improve the reproductive performance of these animals.

Bayesian Estimation of the Logistic Positive Exponent IRT Model

A Bayesian inference approach using Markov Chain Monte Carlo (MCMC) is developed for the logistic positive exponent (LPE) model proposed by Samejima and for a new skewed Logistic Item Response Theory (IRT) model, named Reflection LPE model. Both models lead to asymmetric item characteristic curves (ICC) and can be appropriate because a symmetric ICC treats both correct and incorrect answers symmetrically, which results in a logical contradiction in ordering examinees on the ability scale. A data set corresponding to a mathematical test applied in Peruvian public schools is analyzed, where comparisons with other parametric IRT models also are conducted. Several model comparison criteria are discussed and implemented. The main conclusion is that the LPE and RLPE IRT models are easy to implement and seem to provide the best fit to the data set considered.