Objectives: To define the prevalence of high blood pressure in a representative sample of children and adolescents from the city of Maceió, state of Alagoas, Brazil, and to investigate the association of high blood pressure with age, sex and nutritional status.Methods: This cross-sectional study was carried out from May 2000 to September 2002. Individuals between 7 and 17 years of age were selected among all the 185,702 students from public and private schools. The size of the sample was defined based on the expected prevalence of hypertension for the age group. After randomization, data were collected through a questionnaire. Blood pressure was measured twice. Weight and height were also measured. High blood pressure was defined as systolic and/or diastolic blood pressure over the 95 th percentile in one or in both measures.Results: The final sample included 1,253 students (706 females). One hundred and eighteen students had high blood pressure (mean age 13 years; 44% males). Risk of being overweight and excess weight were identified, respectively, in 9.3 and 4.5% of the students. These variables were significantly associated with high blood pressure. Conclusions:The prevalence of high blood pressure was 9.4%. High blood pressure was significantly more frequent among overweight students and among those at risk for being overweight.
The relation among basal area, light and functional characteristics variation is still an unexplored issue, especially in rainforests with different disturbance regimes. The following hypotheses were tested: 1) basal area of arboreal plants and light availability is a good predictor of the functional characteristics, once it is believed that in forest environments with a lower basal area and much light, functional characteristics values linked to the fast light resources utilization are found in leaves, stem and roots; 2) environments where there is greater light availability, the standard deviation values of the leaf characteristics will be greater. The functional characteristics values were not influenced by the geographic distance (spatial autocorrelation) neither by the species phylogeny. The prediction that in the areas with the lower basal area, values of characteristics associated with the rapid use of the light resource were confirmed for five characteristics: dry leaf matter (LMDC), stem (SDMC) and root (RDMC), the density of wood stem (WDC) and root (WDR). Significant investment was not found in structural carbon (greater dry matter values of leaf and wood) in environments with the greater basal area. It is considered that in urban fragments the disturbances are frequent, it is possible to suppose that plants with lower values of LDMC, DWC, DWR, SDMC, and RDMC have also "established" in the two areas with a greater basal area. It is concluded that in fragments in urban rainforest studied, perturbations may change the succession path due to population dynamics, especially in the area with more abundant light availability and lesser basal area (A4<AB). the study suggests that this greater light input in the A4<AB environment, due to the greater perturbations, would lead plants with the strategy of using a slow resource, favoring those with fast use of the resource, and as a result, there would be less variability of the leaf characteristics in A4<AB. The basal area and light intensity are not good predictors of variations of functional characteristics in the urban fragments studied.
The functional characteristics of plants can be used to understand the changes of vegetation under different environmental pressures, since during the process of succession, the species deal with variations of luminosity, an important resource for the regeneration and growth of plants in humid tropical forests. From the perspective that along the succession there is variation of light availability and that leaf characteristics such as specific leaf area, chlorophyll content and leaf dry matter content are more plastic in groups linked to the rapid acquisition of the resource at the beginning of the succession, it was tested the hypothesis that at the beginning of the succession, where there is greater availability of light, leaf characteristics would be more plastic for the acquisitive group. It was initially found that the geographic distances did not influence the values of the variability indices of the groups, which allows to infer that the distance between the areas does not interfere in the variability of the leaf characteristics. To answer the hypothesis that at the beginning of the succession, in which there is greater light availability, the leaf characteristics would be more plastic for the purchasing group than for the conservative ones, a simple linear regression analysis (ARLS) was performed in the indices of variability for the groups (acquisitive and conservative) and abiotic factor (light) in each area of occurrence. However, the hypothesis that at the beginning of the succession, where there is greater light availability, the characteristics of the leaf would be more plastic for the species was rejected for the species acquisitive, since all indices were reduced for the purchasing group. It is important to take into account that the variation of leaf characteristics as a function of the light availability in an urban tropical fragment is different from what occurs in the classic succession commonly reported, pointing out that possible disturbances caused by the surroundings are the main agents of the functional structure of the community.
Secondary forests play an important role in tropical landscapes and have important ecological functions such as the ability to accumulate biomass. Although the literature points to the convergence between primary and secondary forests, however there are few studies in Atlantic Rainforest in a chronosequence to show it. This study aimed to characterize the changes of floristic composition in a chronosequence (5, 16, 24, 30 years of regeneration and mature forest) in the Atlantic Rainforest. In each forest 30 plots of 10 × 10 m were installed for canopy sampling, and within these 100 m2 were installed plots of 5 × 5 m for sampling the woody sub-forest at the lower left corner. The growth habits analyzed were arboreal (diameter at breast height, DBH ≥ 5 cm), shrubs (DBH < 5 cm and stem diameter at ground level > 1 cm), herbs, epiphytes and climbing plants. The results suggest that from 16 young forests tended to converge with the mature forest in terms of the proportion of growth forms.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.