41 research outputs found

    Precision and accuracy of sampling methods in thinned Pinus taeda L. stands

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    Different sampling methods can be used in forest surveys. It is important to know the precision and accuracy of these sampling methods, and which one is the most appropriate in specific conditions of the forest population. The aim of this study was to compare estimates of a forest inventory performed by different sampling methods with forest census results. The sampling methods evaluated were the fixed-area method and the variable-area methods of Bitterlich, Prodan, and Strand. The data were obtained in a 15-year-old thinned stand of Pinus taeda L., located in the municipality of Teixeira Soares, southern Brazil, with a total area of 12.80 ha. Initially, the forest census was carried out, and subsequently, the sample units for each sampling method were distributed in the stand, with a common starting point. The variables used to compare the sample results with the census means were quadratic diameter, number of trees, basal area, and volume, per hectare. Precision and accuracy were evaluated by sampling error and whether the confidence intervals covered the population means, respectively. The fixed-area and Bitterlich methods stood out in precision for all variables analysed. The fixed-area, Bitterlich and Strand methods with proportion to height provided more accurate estimates. The Prodan method provided inaccurate and imprecise estimates for the variables under analysis, except for the quadratic diameter

    Influence of center-based child care on development of two-year-olds in a Brazilian cohort

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    OBJECTIVE To investigate the association between child care attendance since birth and development in two-years-old Brazilian children. METHODS The study used longitudinal data from the 2015 Pelotas Birth Cohort. The childhood development (cognitive, fine and gross motor skills, and language) at two-years-old children was assessed using INTER-NDA (INTERGROWTH-21st Neurodevelopment Assessment). The child care attendance was measured at ages one and two years and categorized as: a) never attended child care; b) attended some child care (one or two years); and c) always attended child care (one and two years). Demographic, socioeconomic, health, and child stimulation variables were considered as confounders. Crude and adjusted analyses of child care attendance and development were carried out using linear regression. RESULTS Out of the 3,870 infants included in the analyses, around 1/3 attended center-based child care. In crude analyses, attending center-based child care was associated with positive developmental outcomes, except in motor domains. In adjusted analyses, compared to those children that have never attended child care, children who did attend presented higher scores for cognitive development (always in child care: β: 2.44, 95%CI: 0.83–4.05; some child care: β: 1.35, 95%CI: 0.17–2.53). CONCLUSIONS This study suggests that center-based child care may help improve child cognitive development in the Brazilian context. Furthermore, the association was higher for early and continued attendance. Considering the low prevalence of children in external care, it is recommended to improve child care opportunities in early childhood

    Modeling of growth and yield by pluviometric precipitation classes for Eucalyptus sp.

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    Uma das etapas fundamentais na modelagem do crescimento e produção é a identificação dos sítios, geralmente determinados pela relação entre altura dominante e idade. Porém há situações em que se torna interessante o uso de outras variáveis, como a precipitação pluviométrica, devido à grande correlação com a produtividade do povoamento. O objetivo deste estudo foi verificar a influência da estratificação por classes de precipitação pluviométrica no crescimento e produção volumétrica de Eucalyptus sp. Os dados provêm de plantios de híbridos de Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake, do estado da Bahia, distribuídos em sete classes de precipitação, consideradas como estratos conforme o teste de Dette e Neumeyer (2001). Foram determinados os índices de sítio a cada classe de precipitação, sendo utilizada a área basal inicial média em cada um desses sítios. O modelo de Clutter foi empregado para a modelagem e as estimativas de produção foram comparadas pelo teste F de Graybill. A precipitação média influenciou no crescimento em altura dominante. A modelagem realizada por classe de precipitação gerou resultados similares àqueles obtidos pela modelagem sem estratificação, porém com maior precisão, sendo considerada adequada para estimar a produção para povoamentos clonais de eucalipto.Palavras-chave: Eucalipto; ANCOVA não paramétrica; modelo de Clutter. AbstractModeling of growth and yield by pluviometric precipitation classes for Eucalyptus sp. One of the key steps in modeling of growth and yield is the identification of different sites, which are generally determined by the relation of dominant height and age. However, there are situations in which it becomes interesting to use other variables, such as pluviometric precipitation, due to the high correlation with the productivity of the stand. This research aims to investigate influence of stratification by classes of precipitation in volumetric growth and yield of Eucalyptus sp. We collected data in hybrid stands of Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake, from the state of Bahia, Brazil; such stands were distributed in seven classes of precipitation, each considered a site accordingly to Dette and Neumeyer (2001) test. We determined the site index for each class of precipitation, using the initial average basal area in each site. The Clutter model was used for modeling, and production estimates compared by Graybill F test. The average precipitation influenced the dominant height growth. The modeling performed by precipitation classes generated similar results to those obtained by modeling without stratification, but more accurately; we can consider it appropriate to estimate production to clonal eucalyptus stands.Keywords: Eucalypt; nonparametric ANCOVA; Clutter model.AbstractOne of the key steps in modeling of growth and yield is the identification of different sites, which are generally determined by the relation of dominant height and age. However, there are situations in which it becomes interesting to use other variables, such as pluviometric precipitation, due to the high correlation with the productivity of the stand. This research aims to investigate influence of stratification by classes of precipitation in volumetric growth and yield of Eucalyptus sp. We collected data in hybrid stands of Eucalyptus grandis W. Hill ex Maiden x Eucalyptus urophylla S. T. Blake, from the state of Bahia, Brazil; such stands were distributed in seven classes of precipitation, each considered a site accordingly to Dette and Neumeyer (2001) test. We determined the site index for each class of precipitation, using the initial average basal area in each site. The Clutter model was used for modeling, and production estimates compared by Graybill F test. The average precipitation influenced the dominant height growth. The modeling performed by precipitation classes generated similar results to those obtained by modeling without stratification, but more accurately; we can consider it appropriate to estimate production to clonal eucalyptus stands.Keywords: Eucalypt; nonparametric ANCOVA; Clutter model

    The Ingestion and Perspective of Magnesium Consumption by Medicine Students: An Observational Brazilian Study

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    Magnesium is an important nutrient for the organism present in several enzymatic reactions. The reduced daily intake of this mineral (below 310 to 320 mg, for women, and 400 to 420 mg, for men) is associated with several chronic diseases. Thus, based on the hypothesis that medical students have a deficient intake of the mineral, this study sought to examine the intake of macronutrients by medical students at a college in the northwest of São Paulo and their thinking about the importance of the presence of the mineral of the diet. This research is a cross-sectional quali-quantitative study. The data used were obtained through a virtual questionnaire that contained several questions to identify gender, the notion of the importance of correct magnesium intake and the frequency of food consumption. The questionnaire was made available to academics between July and August 2020. The responses to the questionnaire were validated only after acceptance of the informed consent form. Thus, 147 responses were validated, with 92 responses from women and 55 from men. Then, from the amounts of magnesium present in food and the minimum and maximum frequencies of magnesium intake by students, the minimum (male 133.2 mg and female 128.5 mg) and maximum (male 232, 8 and female 229.5) of the daily magnesium intake by the students analyzed and their respective standard deviations, using these data, the Figure of the normal distribution for each type of daily average intake was plotted. Also, an opinion was obtained about the importance of magnesium intake on a scale of 1 to 5 (1 being irrelevant and 5 essential) and, from these data, it was observed that those who considered magnesium intake to be irrelevant (3 responses) presented a minimum and a maximum average (57.03 mg / day and 149.4 mg/day, respectively) of daily mineral intake below the 64 that considered it essential (140.06 mg/day and 238 mg / day) day, respectively). Finally, it is noted that the consumption of both sexes of the interviewees is close and both the maximum mean daily magnesium intake resides below the recommended amounts for daily consumption - mainly individuals of the sex but culino, who have a recommended intake value higher daily dose (400 to 420 mg/day) than females (300 to 310 mg). Thus, this data supports the initial hypothesis of the existence of a deficient daily consumption of magnesium by medical students, also, it can be related to a lower importance attributed to the presence of magnesium in the diet to a lower average daily intake

    Perceived usability of a store and forward telehealth platform for diagnosis and management of oral mucosal lesions : a cross-sectional study

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    EstomatoNet was created in the south of Brazil to provides specialist support over a webbased platform to primary care dentists for diagnosis of oral lesions. To evaluate the usability of EstomatoNet and to identify user perceptions regarding their expectations and difficulties with the system; and to compare the perceptions of regular users of the service to those of first-time users. Sixteen dentists were selected for the study: 8 were frequent users of EstomatoNet and 8 were residents who had never used the Platform. To assess usability, participants were required to request telediagnosis support for a fictional case provided by the research team. During the process of uploading the information and sending the request, users were asked to “think out loud,” expressing their perceptions. The session was observed by an examiner with remote access to the user’s screen (via Skype). After the simulation, users completed the System Usability Scale (SyUS), a validated tool with scores ranging from 0 to 100. The mean SyUS score assigned by frequent users was 84.7±6.6, vs. 82.2±9.3 for residents (satisfactory usability: score above 68). The difference between the groups was not statistically significant (Student t test, P = .55). The residents group took longer (347.1±101.1s) to complete the task than frequent users (252.8±80.3s); however, the difference between the groups was not statistically significant (Student t test, P = .06). In their subjective evaluation, users suggested the inclusion of a field to add further information on outcomes and resolution of the case and changes in the position of the “Send” button to improve workflow. The present results indicate satisfactory usability of EstomatoNet. The Platform seems to meet the needs of users regardless of how experienced they are; nevertheless, a few minor changes in some steps would improve the tool
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