9 research outputs found
Diagnosis of pigmented skin lesions by dermoscopy: web-based training improves diagnostic performance of non-experts
Summary Background Dermoscopy has been shown to enhance the diagnosis of melanoma. However, use of dermoscopy requires training and expertise to be effective. Objectives To determine whether an Internet-based course is a suitable tool in teaching dermoscopy, and to evaluate the diagnostic value of pattern analysis and diagnostic algorithms in colleagues not yet familiar with this technique. Methods Sixteen colleagues who were not experts in dermoscopy were asked to evaluate the dermoscopic images of 20 pigmented skin lesions using different diagnostic methods (i.e. pattern analysis, ABCD rule, seven-point checklist and Menzies' method), before and after an Internet-based training course on dermoscopy. Mean ± SEM sensitivity, specificity and diagnostic accuracy, and kappa (Îș) intraobserver agreement were evaluated for each diagnostic method before and after training for the 16 participants. Differences between mean values were assessed by means of two-tailed Wilcoxon rank-sum tests. Results There was a considerable improvement in the dermoscopic melanoma diagnosis after the Web-based training vs. before. Improvements in sensitivity and diagnostic accuracy were significant for the ABCD rule and Menzies' method. Improvements in sensitivity were also significant for pattern analysis, whereas the sensitivity values were high for the seven-point checklist in evaluations both before and after training. No significant difference was found for specificity before and after training for any method. There was a significant improvement in the Îș intraobserver agreement after training for pattern analysis and the ABCD rule. For the seven-point checklist and Menzies' method there was already good agreement before training, with no significant improvement after training. Conclusions We demonstrated that Web-based training is an effective tool for teaching dermoscopy
Landscape structure in the northern coast of ParanĂĄ state, a hotspot for the brazilian Atlantic Forest conservation
The "Serra do Mar" region comprises the largest remnant of the Brazilian Atlantic Forest. The coast of the Paranå State is part of the core area of the "Serra do Mar" corridor and where actions for biodiversity conservation must be planned. In this study we aimed at characterizing the landscape structure in the APA-Guaraqueçaba, the largest protected area in this region, in order to assist environmental policies of this region. Based on a supervised classification of a mosaic of LANDSAT-5-TM satellite images (from March 2009), we developed a map (1:75,000 scale) with seven classes of land use and land cover and analyzed the relative quantities of forests and modified areas in slopes and lowlands. The APA-Guaraqueçaba is comprised mainly by the Dense Ombrophilous Forest (68.6% of total area) and secondary forests (9.1%), indicating a forested landscape matrix; anthropogenic and bare soil areas (0.8%) and the Pasture/Grasslands class (4.2%) were less representative. Slopes were less fragmented and more preserved (96.3% of Dense Ombrophilous Forest and secondary forest) than lowlands (71.3%), suggesting that restoration initiatives in the lowlands must be stimulated in this region. We concluded that most of the region sustains well-conserved ecosystems, highlighting the importance of Paranå northern coast for the biodiversity maintenance of the Atlantic Forest
Large-Scale Spatial Distribution Patterns of Echinoderms in Nearshore Rocky Habitats
This study examined echinoderm assemblages from nearshore rocky habitats for large-scale distribution patterns with specific emphasis on identifying latitudinal trends and large regional hotspots. Echinoderms were sampled from 76 globally-distributed sites within 12 ecoregions, following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org). Sample-based species richness was overall low (<1â5 species per site), with a total of 32 asteroid, 18 echinoid, 21 ophiuroid, and 15 holothuroid species. Abundance and species richness in intertidal assemblages sampled with visual methods (organisms >2 cm in 1 m(2) quadrats) was highest in the Caribbean ecoregions and echinoids dominated these assemblages with an average of 5 ind m(â2). In contrast, intertidal echinoderm assemblages collected from clearings of 0.0625 m(2) quadrats had the highest abundance and richness in the Northeast Pacific ecoregions where asteroids and holothurians dominated with an average of 14 ind 0.0625 m(â2). Distinct latitudinal trends existed for abundance and richness in intertidal assemblages with declines from peaks at high northern latitudes. No latitudinal trends were found for subtidal echinoderm assemblages with either sampling technique. Latitudinal gradients appear to be superseded by regional diversity hotspots. In these hotspots echinoderm assemblages may be driven by local and regional processes, such as overall productivity and evolutionary history. We also tested a set of 14 environmental variables (six natural and eight anthropogenic) as potential drivers of echinoderm assemblages by ecoregions. The natural variables of salinity, sea-surface temperature, chlorophyll a, and primary productivity were strongly correlated with echinoderm assemblages; the anthropogenic variables of inorganic pollution and nutrient contamination also contributed to correlations. Our results indicate that nearshore echinoderm assemblages appear to be shaped by a network of environmental and ecological processes, and by the differing responses of various echinoderm taxa, making generalizations about the patterns of nearshore rocky habitat echinoderm assemblages difficult