Predicting the distribution of forest tree species using topographic variables and vegetation index in eastern Acre, Brazil

Species distribution modeling has relevant implications for the studies of biodiversity, decision making about conservation and knowledge about ecological requirements of the species. The aim of this study was to evaluate if the use of forest inventories can improve the estimation of occurrence probability, identify the limits of the potential distribution and habitat preference of a group of timber tree species. The environmental predictor variables were: elevation, slope, aspect, normalized difference vegetation index (NDVI) and height above the nearest drainage (HAND). To estimate the distribution of species we used the maximum entropy method (Maxent). In comparison with a random distribution, using topographic variables and vegetation index as features, the Maxent method predicted with an average accuracy of 86% the geographical distribution of studied species. The altitude and NDVI were the most important variables. There were limitations to the interpolation of the models for non-sampled locations and that are outside of the elevation gradient associated with the occurrence data in approximately 7% of the basin area. Ceiba pentandra (samaúma), Castilla ulei (caucho) and Hura crepitans (assacu) is more likely to occur in nearby water course areas. Clarisia racemosa (guariúba), Amburana acreana (cerejeira), Aspidosperma macrocarpon (pereiro), Apuleia leiocarpa (cumaru cetim), Aspidosperma parvifolium (amarelão) and Astronium lecointei (aroeira) can also occur in upland forest and well drained soils. This modeling approach has potential for application on other tropical species still less studied, especially those that are under pressure from logging.

Beyond the income inequality hypothesis and human health: a worldwide exploration

OBJECTIVE: To analyze whether the relationship between income inequality and human health is mediated through social capital, and whether political regime determines differences in income inequality and social capital among countries. METHODS: Path analysis of cross sectional ecological data from 110 countries. Life expectancy at birth was the outcome variable, and income inequality (measured by the Gini coefficient), social capital (measured by the Corruption Perceptions Index or generalized trust), and political regime (measured by the Index of Freedom) were the predictor variables. Corruption Perceptions Index (an indirect indicator of social capital) was used to include more developing countries in the analysis. The correlation between Gini coefficient and predictor variables was calculated using Spearman's coefficients. The path analysis was designed to assess the effect of income inequality, social capital proxies and political regime on life expectancy. RESULTS: The path coefficients suggest that income inequality has a greater direct effect on life expectancy at birth than through social capital. Political regime acts on life expectancy at birth through income inequality. CONCLUSIONS: Income inequality and social capital have direct effects on life expectancy at birth. The "class/welfare regime model" can be useful for understanding social and health inequalities between countries, whereas the "income inequality hypothesis" which is only a partial approach is especially useful for analyzing differences within countries.

Prognostic factors of rheumatic mitral stenosis during pregnancy and puerperium

OBJECTIVE: To identifity characteristics associated with complications during pregnancy and puerperium in patients with rheumatic mitral stenosis. METHODS: Forty-one pregnant women (forty-five pregnancies) with mitral stenosis, followed-up from 1991 to 1999 were retrospectively evaluated. Predictor variables: the mitral valve area (MVA), measured by echocardiogram, and functional class (FC) before pregnancy (NYHA criteria).Maternal events: progression of heart failure, need for cardiac surgery or balloon mitral valvulotomy, death, and thromboembolism. Fetal/neonatal events: abortion, fetal or neonatal death, prematurity or low birth weight (<2,500g), and extended stay in the nursery or hospitalization in newborn ICU. RESULTS: The mean ± SD of age of the patients was 28.8±4.6 years. The eventful and uneventful patients were similar in age and percentage of first pregnancies. As compared with the level 1 MVA, the relative risk (RR) of maternal events was 5.5 (95% confidence interval (CI) =0.8-39.7) for level 2 MVA and 11.4 (95% CI=1.7-74.5) for level 3 MVA. The prepregnancy FC (FC > or = II and III versus I) was also associated with a risk for maternal events (RR=2.7; 95% CI=1.4-5.3).MVA and FC were not importantly associated with these events, although a smaller frequency of fetal/neonatal events was observed in patients who had undergone balloon valvulotomy. CONCLUSION: In pregnant women with mitral stenosis, the MVA and the FC are strongly associated with maternal complications but are not associated with fetal/neonatal events. Balloon mitral valvulotomy could have contributed to reducing the risks of fetal/neonatal events in the more symptomatic patients who had to undergo this procedure during pregnancy.

Some predictors of cardiovascular mortality among the elderly population of Botucatu (SP)

OBJECTIVE: To detect factors associated with cardiovascular mortality in the elderly of Botucatu. METHODS: We evaluated 29 variables of interest in a cohort of patients aged ³60 using data from a survey conducted between 1983/84. The elderly cohort was analyzed in 1992 to detect the occurrence of cardiovascular deaths. Survival analysis was performed using the Kaplan-Meier method, the log-rank test, and Cox regression analysis. Three models were adapted for each group of variables, and a final model was chosen from those variables selected from each group. RESULTS: We identified predictor for cardiovascular death according to age for elderly males not supporting the family, not possessing a vehicle, and previous cardiovascular disease. In elderly females, the predictor variables were previous cardiovascular disease and diabetes mellitus. CONCLUSION: Socioeconomic indicators (family heading and vehicle ownerrship) may be added to well stabilished medical factors (diabete mellitus and hypertension to select target groups for programs intended to reduce deaths due to cardiovascular diseases in elderly people.

Remaining phosphorus estimated by pedotransfer function

Although the determination of remaining phosphorus (Prem) is simple, accurate values could also be estimated with a pedotransfer function (PTF) aiming at the additional use of soil analysis data and/or Prem replacement by an even simpler determination. The purpose of this paper was to develop a pedotransfer function to estimate Prem values of soils of the State of São Paulo based on properties with easier or routine laboratory determination. A pedotransfer function was developed by artificial neural networks (ANN) from a database of Prem values, pH values measured in 1 mol L-1 NaF solution (pH NaF) and soil chemical and physical properties of samples collected during soil classification activities carried out in the State of São Paulo by the Agronomic Institute of Campinas (IAC). Furthermore, a pedotransfer function was developed by regressing Prem values against the same predictor variables of the ANN-based PTF. Results showed that Prem values can be calculated more accurately with the ANN-based pedotransfer function with the input variables pH NaF values along with the sum of exchangeable bases (SB) and the exchangeable aluminum (Al3+) soil content. In addition, the accuracy of the Prem estimates by ANN-based PTF were more sensitive to increases in the experimental database size. Although the database used in this study was not comprehensive enough for the establishment of a definitive pedotrasnfer function for Prem estimation, results indicated the inclusion of Prem and pH NaF measurements among the soil testing evaluations as promising ind order to provide a greater database for the development of an ANN-based pedotransfer function for accurate Prem estimates from pH NaF, SB, and Al3+ values.

Prediction of soil orders with high spatial resolution: response of different classifiers to sampling density

The objective of this work was to evaluate sampling density on the prediction accuracy of soil orders, with high spatial resolution, in a viticultural zone of Serra Gaúcha, Southern Brazil. A digital elevation model (DEM), a cartographic base, a conventional soil map, and the Idrisi software were used. Seven predictor variables were calculated and read along with soil classes in randomly distributed points, with sampling densities of 0.5, 1, 1.5, 2, and 4 points per hectare. Data were used to train a decision tree (Gini) and three artificial neural networks: adaptive resonance theory, fuzzy ARTMap; self‑organizing map, SOM; and multi‑layer perceptron, MLP. Estimated maps were compared with the conventional soil map to calculate omission and commission errors, overall accuracy, and quantity and allocation disagreement. The decision tree was less sensitive to sampling density and had the highest accuracy and consistence. The SOM was the less sensitive and most consistent network. The MLP had a critical minimum and showed high inconsistency, whereas fuzzy ARTMap was more sensitive and less accurate. Results indicate that sampling densities used in conventional soil surveys can serve as a reference to predict soil orders in Serra Gaúcha.

Factors associated with the onset of hypertension in women of 50 years of age or more in a city in Southeastern Brazil

PURPOSE:To evaluate factors associated with hypertension in Brazilian women of 50 years of age or more.METHODS:A cross-sectional population based study using self-reports. A total of 622 women were included. The association between sociodemographic, clinical and behavioral factors and the woman's age at the onset of hypertension was evaluated. Data were analyzed according to cumulative continuation rates without hypertension, using the life-table method and considering annual intervals. Next, a Cox multiple regression analysis model was adjusted to analyze the occurrence rates of hypertension according to various predictor variables. Significance level was pre-established at 5% (95% confidence level) and the sampling plan (primary sampling unit) was taken into consideration.RESULTS:Median age at onset of hypertension was 64.3 years. Cumulative continuation rate without hypertension at 90 years was 20%. Higher body mass index (BMI) at 20–30 years of age was associated with a higher cumulative occurrence rate of hypertension over time (coefficient=0.078; p<0.001). Being white was associated with a lower cumulative occurrence rate of hypertension over time (coefficient= -0.439; p=0.003), while smoking >15 cigarettes/day was associated with a higher rate over time (coefficient=0.485; p=0.004).CONCLUSION:The results of the present study highlight the importance of weight control in young adulthood and of avoiding smoking in preventing hypertension in women aged ≥50 years.

Biomass and mineralmass estimates in a "cerrado" ecosystem

This work aimed to develop allometric equations for tree biomass estimation, and to determine the site biomass in different "cerrado" ecosystems. Destructive sampling in a "campo cerrado" (open savanna) was carried out at the Biological Reserve of Moji-Guaçu, State of São Paulo, southeastern Brazil. This "campo cerrado" (open savanna) grows under a tropical climate and on acid, low nutrient soils. Sixty wood plants were cut to ground level and measurements of diameter, height and weight of leaves and stems were taken. We selected the best equations among the most commonly used mathematical relations according to R² values, significance, and standard error. Both diameter (D) and height (H) showed good relationship with plant biomass, but the use of these two parameters together (DH and D²H) provided the best predictor variables. The best equations were linear, but power and exponential equations also showed high R² and significance. The applicability of these equations is discussed and biomass estimates are compared with other types of tropical savannas. Mineralmass was also estimated. "Cerrados" proved to have very important carbon reservoirs due to their great extent. In addition, high land-use change that takes place nowadays in the "cerrado" biome may significantly affect the global carbon cycle.

El estrato socioeconómico como factor predictor del uso constante de condón en adolescentes

OBJETIVO: El estrato socioeconómico juega un rol importante en las desigualdades en salud. En México, la prevalencia más alta de casos de SIDA se encuentra en población de estratos más bajos. El propósito de lo estudio fue describir el estrato socioeconómico (ajustado por variables psicosociales, situacionales y demográficas) como un factor predictor del uso consistente del condón, en adolescentes. MÉTODOS: Se incluyó en el estudio una muestra de una encuesta previa aplicada a 1.410 adolescentes de 15 a 19 años y estratificada por edad, género y estrato socioeconómico de Guadalajara, México. El análisis fue aplicado sobre los 251 adolescentes que reportaron actividad sexual. El análisis estadístico se realizó mediante Ji Cuadrada, t-test, ANOVA y regresión logística. RESULTADOS: La frecuencia de uso consistente de condón fue 30,7% y hubo una prevalencia de uso irregular. El estrato socioeconómico alto fue el principal predictor (OR= 11,1, CI95%= 2,6-47,6). Otros predictores significativos fueron el género masculino, el soporte de los pares y el nivel alto de conocimientos sobre VIH/SIDA. CONCLUSIÓN: El estrato socioeconómico es un importante factor predictor del uso consistente del condón.

Predictive value of clinical and electrophysiological variables in patients with chronic chagasic cardiomyopathy and nonsustained ventricular tachycardia

OBJECTIVE: Risk stratification of patients with nonsustained ventricular tachycardia (NSVT) and chronic chagasic cardiomyopathy (CCC). METHODS: Seventy eight patients with CCC and NSVT were consecutively and prospectively studied. All patients underwent to 24-hour Holter monitoring, radioisotopic ventriculography, left ventricular angiography, and electrophysiologic study. With programmed ventricular stimulation. RESULTS: Sustained monomorphic ventricular tachycardia (SMVT) was induced in 25 patients (32%), NSVT in 20 (25.6%) and ventricular fibrillation in 4 (5.1%). In 29 patients (37.2%) no arrhythmia was inducible. During a 55.7-month-follow-up, 22 (28.2%) patients died, 16 due to sudden death, 2 due to nonsudden cardiac death and 4 due to noncardiac death. Logistic regression analysis showed that induction was the independent and main variable that predicted the occurrence of subsequent events and cardiac death (probability of 2.56 and 2.17, respectively). The Mantel-Haenszel chi-square test showed that survival probability was significantly lower in the inducible group than in the noninductible group. The percentage of patients free of events was significantly higher in the noninducible group. CONCLUSION: Induction of SMVT during programmed ventricular stimulation was a predictor of arrhythmia occurrence cardiac death and general mortality in patients with CCC and NSVT.

Is female sex an independent predictor of in-hospital mortality in acute myocardial infarction?

OBJECTIVE: To assess whether female sex is a factor independently related to in-hospital mortality in acute myocardial infarction. METHODS: Of 600 consecutive patients (435 males and 165 females) with acute myocardial infarction, we studied 13 demographic and clinical variables obtained at the time of hospital admission through uni- and multivariate analysis, and analyzed their relation to in-hospital death. RESULTS: Females were older (p<0.001) and had a higher incidence of hypertension (p<0.001). Males were more frequently smokers (p<0.001). The remaining risk factors had a similar incidence among both sexes. All variables underwent uni- and multivariate analysis. Through univariate analysis, the following variables were found to be associated with in-hospital death: female sex (p<0.001), age >70 years (p<0.001), the presence of previous coronary artery disease (p=0.0004), previous myocardial infarction (p<0.001), infarction in the anterior wall (p=0.007), presence of left ventricular dysfunction (p<0.001), and the absence of thrombolytic therapy (p=0.04). Through the multivariate analysis of logistic regression, the following variables were associated with in-hospital mortality: female sex (p=0.001), age (p=0.008), the presence of previous myocardial infarction (p=0.02), and left ventricular dysfunction (p<0.001). CONCLUSION: After adjusting for all risk variables, female sex proved to be a variable independently related to in-hospital mortality in acute myocardial infarction.

High-Sensitivity C-Reactive Protein as a Predictor of Cardiovascular Events after ST-Elevation Myocardial Infarction

Background: The association between high-sensitivity C-reactive protein and recurrent major adverse cardiovascular events (MACE) in patients with ST-elevation myocardial infarction who undergo primary percutaneous coronary intervention remains controversial. Objective: To investigate the potential association between high-sensitivity C-reactive protein and an increased risk of MACE such as death, heart failure, reinfarction, and new revascularization in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention. Methods: This prospective cohort study included 300 individuals aged >18 years who were diagnosed with ST-elevation myocardial infarction and underwent primary percutaneous coronary intervention at a tertiary health center. An instrument evaluating clinical variables and the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores was used. High-sensitivity C-reactive protein was determined by nephelometry. The patients were followed-up during hospitalization and up to 30 days after infarction for the occurrence of MACE. Student's t, Mann-Whitney, chi-square, and logistic regression tests were used for statistical analyses. P values of ≤0.05 were considered statistically significant. Results: The mean age was 59.76 years, and 69.3% of patients were male. No statistically significant association was observed between high-sensitivity C-reactive protein and recurrent MACE (p = 0.11). However, high-sensitivity C-reactive protein was independently associated with 30-day mortality when adjusted for TIMI [odds ratio (OR), 1.27; 95% confidence interval (CI), 1.07-1.51; p = 0.005] and GRACE (OR, 1.26; 95% CI, 1.06-1.49; p = 0.007) risk scores. Conclusion: Although high-sensitivity C-reactive protein was not predictive of combined major cardiovascular events within 30 days after ST-elevation myocardial infarction in patients who underwent primary angioplasty and stent implantation, it was an independent predictor of 30-day mortality.

Gross proteinuria is a strong risk predictor for cardiovascular mortality in Brazilian type 2 diabetic patients

Increased proteinuria is recognized as a risk predictor for all-cause and cardiovascular mortality in diabetic patients; however, no study has evaluated these relationships in Brazilian patients. The aim of this study was to investigate the prognostic value of gross proteinuria for all-cause and cardiovascular mortalities and for cardiovascular morbidity in a cohort study of 471 type 2 diabetic individuals followed for up to 7 years. Several clinical, laboratory and electrocardiographic variables were obtained at baseline. The relative risks for all-cause, cardiovascular and cardiac mortalities and for cardiovascular and cardiac events associated with the presence of overt proteinuria (>0.5 g/24 h) were assessed by Kaplan-Meier survival curves and by multivariate Cox regression model. During a median follow-up of 57 months (range 2-84 months), 121 patients (25.7%) died, 44 from cardiovascular and 30 from cardiac causes, and 106 fatal or non-fatal cardiovascular events occurred. Gross proteinuria was an independent risk predictor of all-cause, cardiovascular and cardiac mortalities and of cardiovascular morbidity with adjusted relative risks ranging from 1.96 to 4.38 for the different endpoints. This increased risk remained significant after exclusion of patients with prior cardiovascular disease at baseline from the multivariate analysis. In conclusion, gross proteinuria was a strong predictor of all-cause, cardiovascular and cardiac mortalities and also of cardiovascular morbidity in a Brazilian cohort of type 2 diabetic patients. Intervention studies are necessary to determine whether the reduction of proteinuria can decrease morbidity and mortality of type 2 diabetes in Brazil.

Glomerular damage as a predictor of renal allograft loss

Interstitial fibrosis and tubular atrophy (IF/TA) are the most common cause of renal graft failure. Chronic transplant glomerulopathy (CTG) is present in approximately 1.5-3.0% of all renal grafts. We retrospectively studied the contribution of CTG and recurrent post-transplant glomerulopathies (RGN) to graft loss. We analyzed 123 patients with chronic renal allograft dysfunction and divided them into three groups: CTG (N = 37), RGN (N = 21), and IF/TA (N = 65). Demographic data were analyzed and the variables related to graft function identified by statistical methods. CTG had a significantly lower allograft survival than IF/TA. In a multivariate analysis, protective factors for allograft outcomes were: use of angiotensin-converting enzyme inhibitor (ACEI; hazard ratio (HR) = 0.12, P = 0.001), mycophenolate mofetil (MMF; HR = 0.17, P = 0.026), hepatitis C virus (HR = 7.29, P = 0.003), delayed graft function (HR = 5.32, P = 0.016), serum creatinine ≥1.5 mg/dL at the 1st year post-transplant (HR = 0.20, P = 0.011), and proteinuria ≥0.5 g/24 h at the 1st year post-transplant (HR = 0.14, P = 0.004). The presence of glomerular damage is a risk factor for allograft loss (HR = 4.55, P = 0.015). The presence of some degree of chronic glomerular damage in addition to the diagnosis of IF/TA was the most important risk factor associated with allograft loss since it could indicate chronic active antibody-mediated rejection. ACEI and MMF were associated with better outcomes, indicating that they might improve graft survival.

Effects of growth reducer and nitrogen fertilization on morphological variables, SPAD index, interception of radiation and productivity of wheat

ABSTRACT The objective of this study was to evaluate the effect of growth reducer and nitrogen fertilization on morphological variables, SPAD index, radiation interception, and grain yield of three cultivars of wheat. The experimental design was a randomized block in factorial scheme 3x5x2, with three cultivars (Mestre, Iguaçú and Itaipú), five nitrogen doses (0, 40, 80, 120, 160 Kg ha-1), and application or no application of a growth reducer, with three replications. The following characteristics were evaluated: plant height, SPAD index, leaf area index (LAI), Global Radiation Interception (GRI) and grain yield. The Tukey test (p < 0.05) was used for the comparison between the means of cultivar and growth reducer factors, and for a regression analysis to evaluate N levels. Increasing the dose of nitrogen promotes an increase in LAI of plants of wheat crops differently among cultivars, which leads to a greater degree of global radiation interception. At doses higher or equal to 120 Kg ha-1 of nitrogen, there are significant differences in grain yield between treatments with and without the application of the growth reducer. The significant interaction between growth reducer and nitrogen dose, showed that applications of growth reducer increase the GRI at doses above and below 80 Kg ha-1 of nitrogen. Nitrogen rates of 138 and 109 Kg ha-1 are responsible for maximum grain yields of wheat, which is 4235 and 3787 Kg ha-1 with and without the use of growth reducer, respectively.