Physiological and growth responses of several genotypes of common purslane (Portulaca oleracea L.) under mediterranean semi-arid conditions

Common purslane (Portulaca oleracea L.) is a drought-tolerant weed cultivated for its fresh leaves and stems. In the present study, a field experiment was conducted to determine plant development and photosynthesis of several common purslane genotypes in a high-density planting system. The experiment was carried out according to randomized complete block design with four replications per treatment. Four local populations and two commercial cultivars of common purslane were studied. During the experiment, plant biomass, plant height, leaf relative chlorophyll content (SPAD values), stomatal conductance (gs) and photosynthetic rate (A) were recorded. From the results of our study significant differences in plant height and biomass were observed among the studied genotypes. The lowest height and biomass were found in genotype 'Domokos' whose growth was prostrate to semi-prostrate, whereas all the other genotypes had erect growth. Differences were also observed in physiological parameters. In particular, the relative chlorophyll content (SPAD value) was the highest for genotype 'Domokos', whereas stomatal conductance and photosynthetic rates were the lowest for the same genotype. Biomass yield had also positive and significant correlation with photosynthetic rate and plant height. Our results indicate that the tested genotypes had significant differences in growth habit and physiological parameters. Comparing the tested genotypes, it could be suggested that apart from genotype 'Domokos' which had lower biomass yield due to its growth habit, the rest of the genotypes could be suitable for commercial purposes and proposed as an alternative crop in semi-arid regions of the Mediterranean basin

Halophytic herbs of the Mediterranean basin: An alternative approach to health

Wild native species are usually grown under severe and stressful conditions, while a special category includes halophytic species that are tolerant to high salinity levels. Native halophytes are valuable sources of bioactive molecules whose content is higher in saline than normal conditions, since the adaptation to salinity mechanisms involve apart from changes in physiological functions the biosynthesis of protectant molecules. These compounds include secondary metabolites with several beneficial health effects which have been known since ancient times and used for medicinal purposes. Recent trends in pharmaceutical industry suggest the use of natural compounds as alternative to synthetic ones, with native herbs being strong candidates for this purpose due to their increased and variable content in health promoting compounds. In this review, an introductory section about the importance of native herbs and halophyte species for traditional and modern medicine will be presented. A list of the most important halophytes of the Mediterranean basin will follow, with special focus on their chemical composition and their reported by clinical and ethnopharmacological studies health effects. The review concludes by suggesting future requirements and perspectives for further exploitation of these valuable species within the context of sustainability and climate change. © 2018 Elsevier Lt

A genetically optimized level set approach to segmentation of thyroid ultrasound images

This paper presents a novel framework for thyroid ultrasound image segmentation that aims to accurately delineate thyroid nodules. This framework, named GA-VBAC incorporates a level set approach named Variable Background Active Contour model (VBAC) that utilizes variable background regions, to reduce the effects of the intensity inhomogeneity in the thyroid ultrasound images. Moreover, a parameter tuning mechanism based on Genetic Algorithms (GA) has been considered to search for the optimal VBAC parameters automatically, without requiring technical skills. Experiments were conducted over a range of ultrasound images displaying thyroid nodules. The results show that the proposed GA-VBAC framework provides an efficient, effective and highly objective system for the delineation of thyroid nodules. © 2007 Springer Science+Business Media, LLC

Microarray-MD: A system for exploratory analysis of microarray gene expression data

In this paper, we present Microarray Medical Data explorer (Microarray-MD), a novel software system that is able to assist in the exploratory analysis of gene expression microarray data. It implements a combination scheme of multiple Support Vector Machines, which integrates a variety of gene selection criteria and allows for the discrimination of multiple diseases or subtypes of a disease. The system can be trained and automatically tune its parameters with the provision of pathologically characterized gene expression data to its input. Given a set of new, uncharacterized, patient's data as input, it outputs a decision on the type or the subtype of a disease. A graphical user interface provides easy access to the system operations and direct adjustment of its parameters. It has been tested on various publicly available datasets. The overall accuracy it achieves was estimated to exceed 90%. © 2006 Elsevier Ireland Ltd. All rights reserved

An active contour model guided by LBP distributions

The use of active contours for texture segmentation seems rather attractive in the recent research, indicating that such methodologies may provide more accurate results. In this paper, a novel model for texture segmentation is presented, combining advantages of the active contour approach with texture information acquired by the Local Binary Pattern (LBP) distribution. The proposed LBP scheme has been formulated in order to capture regional information extracted from distributions of LBP values, characterizing a neighborhood around each pixel, instead of using a single LBP value to characterize each pixel. The log-likelihood statistic is employed as a similarity measure between the LBP distributions, resulting to more detailed and accurate segmentation of texture images. © Springer-Verlag Berlin Heidelberg 2006