Light distribution on <i>citrus canopy</i> affects physiological parameters and fruiting pattern

Light interception by the orange tree canopy during flower bud differentiation and subsequent flowering and fruit setting has been monitored by continuous data recording from 48 silicon cells distributed in different canopy zones. Two experimental conditions have been tested: trees artificially shaded by a black nylon net cage, and non-shaded trees. Observations were made on the total radiation accumulated in the different canopy zones, and they were related to photosynthetic activity, stomatal conductance) flowering and fruiting pattern, and fruit quality. The different light distribution affected both photosyntesis and stomatal conductance: in fact, they were both drastically reduced in shaded trees, and a significant decrease was also found in both shaded and unshaded trees in relation to different canopy zones. A significant decrease of flowering and fruit setting was found from the top of the canopy to the bottom and from outside to inside, in relation to the different amount of radiant energy availability. Finally significant differences were found on fruit quality

Three-point checklist of dermoscopy: A new screening method for early detection of melanoma

Background: Dermoscopy used by experts has been demonstrated to improve the diagnostic accuracy for melanoma. However, little is known about the diagnostic validity of dermoscopy when used by nonexperts. Objective: To evaluate the diagnostic performance of nonexperts using a new 3-point checklist based on a simplified dermoscopic pattern analysis. Methods: Clinical and dermoscopic images of 231 clinically equivocal and histopathologically proven pigmented skin lesions were examined by 6 nonexperts and 1 expert in dermoscopy. For each lesion the nonexperts assessed 3 dermoscopic criteria (asymmetry, atypical network and blue-white structures) constituting the 3-point method. In addition, all examiners made an overall diagnosis by using standard pattern analysis of dermoscopy. Results: Asymmetry, atypical network and blue-white structures were shown to be reproducible dermoscopic criteria, with a kappa value ranging from 0.52 to 0.55. When making the overall diagnosis, the expert had 89.6% sensitivity for malignant lesions (tested on 68 melanomas and 9 pigmented basal cell carcinomas), compared to 69.7% sensitivity achieved by the nonexperts. Remarkably, the sensitivity of the nonexperts using the 3-point checklist reached 96.3%. The specificity of the expert using overall diagnosis was 94.2% compared to 82.8 and 32.8% achieved by the nonexperts using overall diagnosis and 3-point checklist, respectively. Conclusion: The 3-point checklist is a valid and reproducible dermoscopic algorithm with high sensitivity for the diagnosis of melanoma in the hands of non-experts. Thus it may be applied as a screening procedure for the early detection of melanoma. Copyright (C) 2004 S. Karger AG, Basel