Stratified Sampling System Research Articles

Preeklamptik Anne Bebeklerinde Ortalama Platelet Hacmi (MPV) ve Neonatal Sonuçlar

Aim
 Preeclampsia may cause both maternal and neonatal complications. Uteroplacental dysfunction is one of the reasons of fetal and neonatal complications in preeclampsia. Recent findings about the etiology and pathogenesis of the disease shows that inflammation is one of the factors responsible for maternal complications, thus neonatal complications should be associated with the same inflammatory process. We considered evaluating mean platelet volume (MPV) of infants born to mothers with preeclampsia, based on the findings of elevated MPV values in pregnant women with preeclampsia. 
 
 Materials and methods
 This study was carried out at the Neonatal Intensive Care Unit of Hacettepe University Ihsan Dogramacı Children’s Hospital and consisted of 148 infants born to mothers with preeclampsia and 147 infants as a control group which were selected by stratified sampling system. Hematological parameters (mean platelet volume, hemoglobin values, white blood cell and platelet counts) and common neonatal morbidities (small for gestational age, respiratory distress syndrome, necrotizing enterocolitis, intraventricular hemorrhage and patent ductus arteriosus) were evaluated between groups. 
 
 Results
 The infants of mothers with preeclampsia had significantly elevated MPV and hemoglobin values (p

Woody species composition, structure, and diversity of homegarden agroforestry systems in southern Tigray, Northern Ethiopia

Nowadays, the conservation of biodiversity is a major environmental challenge globally. Homegarden agroforestry systems (HGAFs) have a large potential for biodiversity conservation. However, little attention has been given to the relative importance of HGAFs in terms of biodiversity conservation. The present study, therefore, aimed to estimate and compare the woody species diversity and structure of HGAFs and adjacent natural forest (NF) in Northern Ethiopia. Three sites were purposively selected based on the presence of HGAFs and NF adjacent to each other. A stratified sampling system was used to select representative homegardens from different wealth categories. In NF, a systematic transect sampling technique was employed. A total of 90 sample plots (10 m × 20 m) were used to collect vegetation data. A total of 32 species representing 26 genera and 20 families were identified from the studied HGAFs and NF. Thirty woody species belonging to 24 genera and 20 families were recorded in the HGAFs whereas, 11 species, belonging to 9 genera and 8 families were recorded in the NF. Native woody species accounted for 66% of all woody species recorded in both HGAFs and NF. Stem density, richness, and diversities of woody species were significantly higher in HGAFs than in NF (p ≤ 0.05). Trees and shrubs in the HGAFs had significantly lower stem diameters, height, and basal area than the adjacent NF (p ≤ 0.05). The results show that HGAFs complements the NF for biodiversity conservation and supports in counteracting the loss of woody species from the natural ecosystem. Hence, promoting HGAFs habitats in human-dominated landscapes should be part of the biodiversity conservation strategy.

Estimating soil erosion intensity in susceptible areas based on a comprehensive stratified sampling system associated with the geographical information system

An error-free and fast approach for the identification of the area dynamics of soil erosion intensity (SEI) is essential for local governments. In this study, a simple method combination of the vegetation cover, gradient slope, and land use coupling index (vegetation and slope coupling index) model with field sampling unit schemes was explored to estimate the area variations of SEI between the years 1998 and 2009. The obtained results show that the minimum average prediction accuracy (PA) for sampling units was 94% among different land use types, whereas the maximum PA was 98.5%. Although PAs for different land use types showed discrepancies, the trend clearly depicted higher rates of sampling units and lower relative errors. The average fitting accuracies (FAs) of the sampling units were 98.84%, 97.92%, and 97.26%, respectively, based on different proposed strategies, whereas the FAs of the extrapolation results were 94.77%, 87.57%, and 92.41%, respectively. In addition, the extrapolation results were found to be less efficient than the sampling units. However, this is acceptable, considering the field observation workloads and time consumption. Therefore, this study provides a promising scheme for the rapid estimation of the area dynamics of SEI, which will be useful for estimating the SEI in other areas.

Neospora caninum seropositivity in cattle breeds in the South Fluminense Paraíba Valley, state of Rio de Janeiro

The infection by Neospora caninum of different cattle breeds in dairy properties in two municipalities of the South Fluminense Paraíba Valley, state of Rio de Janeiro, was evaluated. Considering a sampling universe of 2,491 cows, blood samples were collected from 563 dairy cows in 57 farms, which were randomically selected in proportion to the number of animals, using a random stratified sampling system. For each property the number of selected cows was proportional to the herd size. Abortion or other reproductive disorders were not considered as criteria for selecting the animals, and seropositivity was determined by indirect enzyme-linked immunosorbent assay (ELISA). A high association (p=0.006) between seropositivity and racial patterns was found. The analysis revealed that in comparison of pure black-and-white Holstein cows versus Zebu (p=0.0028), Holstein cows showed 2.65 times greater odds for seropositivity. In the same way, by comparing black-and-white Holstein versus Zebu + crossbreed Zebu/Holstein (p=0.01), it was noted that there is 2.23 times more chance for seropositivity in Holstein cattle. There were no significant differences concerning the comparison of Holstein cattle versus crossbreed Zebu/Holstein (p=0.08) or Zebu versus crossbreed Zebu/Holstein (p=0.11). This study supports the hypothesis that there is a close association between cattle breeds and the frequency of infection by N. caninum.

Painel amostral para estimativa de áreas agrícolas

O objetivo deste trabalho foi desenvolver metodologia que integre sensoriamento remoto e sistema de informações geográficas (SIG) para criar um painel amostral e alocar segmentos regulares por meio de um sistema de amostragem aleatória estratificada. Diferentes estratos foram obtidos por meio da classificação de imagens de satélite. Em cada estrato foi realizado sorteio para a seleção dos segmentos amostrais, os quais foram visitados para delimitar as diversas culturas e estimar a área. Na estimativa da área plantada por cultura, para toda a região, utilizou-se o estimador por expansão direta por meio de um procedimento semi-automático. A metodologia reduziu tanto a subjetividade do percentual da área agrícola estimada no estrato, quanto o tempo de construção do painel amostral.

Distribution patterns of plant communities on Santiago Island, Cape Verde

Abstract. Question: What is the composition, ecology and distribution of the main plant communities on Santiago Island?Location: Santiago Island (Cape Verde archipelago).Methods: 308 plots were established using a stratified sampling system according to habitat type; random sampling was employed in each habitat type. Floristic and ecological (topographic, edaphic, climatic and land use) data were collected and analysed using classification and ordination methods and regression analysis.Results: The classification results led to the recognition often plant communities. Ordination pointed to the importance of altitudinal gradient, slope angle and soil moisture in vegetation variation, as well as some categories of land use, land form or soil type. Regression analysis of sample distributions in ordination space and altitude, according to the two main types of slope aspect — leeward vs. windward — produced altitude differences of ca. 100 m. Variation in rainfall proved more effective at lower altitudes, resulting in the differentiation of more vegetation belts. Slope angle proved to be more important for vegetation differentiation when values exceeded 40°, particularly at medium and higher altitudes. Plant communities are mainly dominated by herbaceous annual species, many of which are exotic.Conclusions: Two main phyto‐ecological zones can be distinguished: a xerophilous zone (up to 300/400 m) and a mesophilous zone (above 300/400 m). The zonal communities (four mesophilous and three xerophilous) were distributed in altitudinal belts (mainly reflected in a precipitation gradient); different altitudinal ranges were estimated for these communities according to aspect. The two hygrophilous and one psammophilous communities presented an azonal distribution.

An investigation of former land-use activity through the physical and chemical analysis of soils from the Isle of Lewis, Outer Hebrides

In this study, the impact of human activity on the pedological environment of an agriculturally marginal site is investigated and the use of soils for analysing the site's land-use history is discussed. For townships such as Knockaird (Isle of Lewis), for which detailed layout/location prior to crofting is not recoverable through plans, such analyses can offer a prospective approach. The nature of traditional Hebridean farming provides an essential background to this prospective or diagnostic approach using soil analysis. Arable farming, at least by the eighteenth century, was characterized by labour-intensive techniques of husbandry with vast inputs of labour required to help transfer manurial supplements such as manure, seaweed, peat and turf. These practices had a considerable impact on the soil environment. A stratified sampling system was undertaken over the township of Knockaird and 335 topsoil samples were collected along predetermined transect lines. Of the seven soil properties investigated (topsoil depth, pH, loss-on-ignition, K, P, Ca, Mg), enrichments of K and P clearly identify the suspected location of the pre-crofting settlement of Knockaird. Sites enriched only in P are a less reliable indicator of human habitation, possibly because P enrichment may result from additions of animal manure as well as by human habitation of an area. Enrichments of K and Ca respectively, observed running the length of two individual crofts, do not appear related to any pre-crofting use of the land but to recent crofting activity. The Ca anomaly suggests liming, whereas the enhanced K levels suggest additions of K-rich fertilizer. This study highlights the importance of identifying the spatial covariance of elements and the need for several lines of geoarchaeological evidence when interpreting former land-use activity through the prospective analysis of soils. Copyright © 2000 John Wiley & Sons, Ltd.

Climatic responses of plant species on Tenerife, The Canary Islands

Abstract. The distribution of 44 common vascular plant species on Tenerife, The Canary Islands, has been related to the variation in temperature and precipitation. Frequency values for these speceis were obtained using a stratified sampling system with 200 10 m x 10 m plots distributed all over the island. A model is proposed relating variation in vegetation to altitude according to two main climatic gradients occurring between the 3718 m summit and the coastline of Tenerife. The vascular plants have been classified into guilds according to their presumed tolerance to cold and drought; one remainder group includes species which are randomly distributed without any relation to climatic variation. Differences between the guild structure suggested here and common knowledge of plant species occurrence in the well‐known vegetation belts of Tenerife are explained by assuming disturbance and local ground‐water availability as additional decisive factors.

Ultrastructural analysis of regional type II cell development within fetal and neonatal lungs

Type II cells within guinea pig lungs were studied beginning when lamellar bodies (LB) were first identifiable, to determine the pattern of their ultrastructural maturation through parturition and to search for regional differences suggested for other species in their numbers or maturity within the same lung. Fetuses were examined at gestational ages of 55, 60, and 65 days, as were newborn within 2 h of birth at 68 days. The stratified sampling system divided left lungs into nine blocks from each cranial and caudal lobe for electron-microscopic morphometry. Type II cells were compared among blocks within lobes, between lobes within age groups, and among ages for volume densities [VV(ep2, t)], numerical densities [NV(ep2, t)], and surface densities [SV(ep2, t)] per block; total tissue volumes [V(ep2)], numbers [N(ep2)], and cumulative surface areas [S(ep2)] per lung; and the VV(lb, ep2) and V(lb) of their LB. Within lobes, there were no significant differences among blocks for any parameter. Within age groups, significant interlobar differences were limited only to NV(ep2, t) (cranial greater than caudal at day 55, P less than 0.001). In age-by-age comparisons, the V(ep2), NV(ep2), and S(ep2) each increased dramatically from day 55 to 60 (P less than 0.001) but then remained unchanged through parturition. However, both VV(lb, ep2) and V(lb) increased linearly with fetal age (day 55 less than 60 less than 65 less than newborn), with VV(lb, ep2) achieving 18% type II cell volume in the postpartum group.(ABSTRACT TRUNCATED AT 250 WORDS)

The dispersion of brood galleries of Xyleborus fornicatus Eichh. (Coleoptera, Scolytidae) in tea plants

AbstractThe dispersion and density of brood galleries of the wood-boring ambrosia beetle, Xyleborus fornicatus Eichh., in the tea plant depends on the type of branch (primary, secondary and tertiary) and not on the total available length of branch nor on branch thickness. Within the different branch types, branch lengths and the numbers of galleries contained in them are directly related. Significantly more galleries are formed in the primary branches than in the secondaries, which themselves carry more than the tertiaries. For precise estimation of Xyleborus population density, a stratified sampling system, representing the different branch classes, will be required.