Dynamic training using multistage clustering for face recognition

A novel face recognition algorithm that uses dynamic training in a multistage clustering scheme is presented and evaluated. This algorithm uses discriminant analysis to project the face classes and a clustering algorithm to partition the projected face data, thus forming a set of discriminant clusters. Then, an iterative process creates subsets, whose cardinality is defined by an entropy-based measure, that contain the most useful clusters. The best match to the test face is found when only a single face class is retained. This method was tested on the ORL, XM2VTS and FERET face databases, whereas the UMIST database was used in order to train the proposed algorithm. Experimental results indicate that the proposed framework provides a promising solution to the face recognition problem.     

Banana: cultivars,biotechnological approaches and genetic transformation

Genetic modification of banana has been considered as a path towards increasing the value of this crop according to health and nutrition in developing countries. Banana as a crop is one of the most important and widely consumed fruits as a weaning food by children and as a starchy staple for all other consumers. As well as providing a low cost and easily produced source of energy, bananas are also rich in certain minerals and in vitamins A, C and B6. Growing urbanisation in many developing countries upgraded the crop importance as a source of revenue, occasionally providing the main source of income for rural communities. Genetically modified organism bananas have been advocated as carrier for vaccines and as a source of carotenoids that can counteract debilitating vitamin A deficiency. The rather high vulnerability of banana to pests and diseases triggered biotechnological applications in an attempt to produce new, more resistant banana cultivars. However, the potential biosafety of genetically modified banana and its applications should be taken into account prior to its extensive usage. The current survey summarises the most important biotechnological techniques (in vitro culture, DNA fingerprinting, somatic emrbyogenesis, DNA flow cytometry, etc.) and applications (micropropagation, in vitro selection, somaclonal variation, protoplast fusion, haploid production, etc.) in banana and emphasises on genetic transformation in conjunction with the expressed gene and modified trait aiming at a further improvement of this crop.     

Inhibition of the decrease of volatile esters and terpenes during storage of a white wine and a model wine medium by glutathione and N-acetylcysteine

Glutathione and N‐acetylcysteine, each at 20 mg L^?1, were tested as inhibitors of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by glutathione and N‐acetylcysteine, each at 0–20 mg L^?1, was also tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. Glutathione or N‐acetylcysteine significantly restricted the decrease of these volatiles. In the model medium, each thiol inhibited the decrease of the three volatiles in a dose‐dependent manner. N‐acetylcysteine inhibited the decrease of all three volatiles at 2.5 mg L^?1 while glutathione at 2.5 or 5.0 mg L^?1. The present results indicate that glutathione and N‐acetylcysteine may be taken into account as potent inhibitors of the disappearance of aromatic esters and terpenes in wines.     

Physico‐chemical and sensory attributes in conjunction with multivariate analysis of two potato (Solanum tuberosum L.) cultivars after 90 days of storage: an exploratory authentication study

Two cultivars of potato (Spunta and Agria), were studied in terms of their physico‐chemical and sensory characteristics. These cultivars were cultivated in three geographical regions of Greece (Macedonia, North Greece; Thessaly, Central Greece; Peloponnese, South Greece) and were stored for 90 days after harvesting. The physico‐chemical characteristics of the tubers determined, were pH, total acidity, firmness, dry matter and content in Ν, in Κ, P, Cu, Mn, Zn and Fe. The sensory characteristics measured for raw tubers of potato after storage, were skin colour, skin brightness, internal colour, surface roughness, odour intensity, moistness, surface wrinkling and stains while the sensory characteristics measured for the boiled tubers of potato were odour intensity, moistness, special taste, sweet taste, aftertaste persistence, metal taste, pastiness, mastication, flavour intensity, elasticity and overall acceptability. The application of multivariate analysis (principal component analysis, cluster analysis and discriminant analysis), revealed a variety of relations between the various parameters and resulted in satisfactory grouping either per geographical region or per cultivar.     

Impact of hot water treatment on sprouting,membrane permeability,sugar content and chip colour of reconditioned potato tubers following long‐term cold storage

BACKGROUND: The efficacy of hot water treatment in facilitating successful reconditioning of processing potato (Solanum tuberosum L.) cultivar Hermes following 6 months cold storage at 4.5 °C was examined. Tubers were subjected to hot water treatments (HWTs) at 52.5, 55.0, 57.5 and 60.0 °C for 0–60, 0–50, 0–40 and 0–20 min, respectively, and then reconditioned for 20 days at 16 °C before evaluated for sprouting, fresh weight loss, membrane permeability, sugar content and processing quality. RESULTS: The study demonstrates that in order to achieve complete inhibition of sprouting during potato reconditioning HWTs must exceed the thermal tolerance threshold of the tubers. Short‐duration HWT was effective in retarding sprout growth and tuber dehydration without significantly affecting storage parenchyma membrane permeability, tuber sugar content or processing quality. On the contrary, prolonged HWT caused extensive heat damage, loss of membrane integrity and induced an increase in tuber sucrose and reducing sugar content resulting in deterioration of chip colour in proportion to treatment duration. CONCLUSION: Although HWT at 52.5–60 °C following long‐term cold storage did not improve the processing quality of potato tubers after 20 days of reconditioning, future work is needed to evaluate the effect of short‐duration HWT on the permissible extent of reconditioning and subsequent processing quality. Copyright © 2008 Society of Chemical Industry     

Sulphate resistance of lime-based barium mortars

This work studies the effect of barium hydroxide on the sulphate-resistance of lime-based mortars when used as an additive material to the lime binder. The overall aim of the work is to study the potential of barium hydroxide in producing a mixed binder with lime, which is able to fix the sulphate ions, block the diffusion of sulphate solutions and therefore, reduce the degradation rate of mixtures.The durability of different mixtures was studied through sulphate salt crystallisation and acid rain simulation tests, along with the characterisation of their pore-space properties. X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) were used for materials characterisation. Experimental results proved that barium hydroxide increases the durability of hardened mixtures against sulphate attack, without affecting the microstructure characteristics.     

Antibacterial and anti-PAF activity of lipid extracts from sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata)

The anti-PAF and the antibacterial activities of lipid extracts obtained from cultured sea bass (Dicentrarchus labrax) and cultured gilthead sea bream (Sparus aurata) were evaluated. Total lipids of sea bass and gilthead sea bream exerted PAF-like activity while, in higher amounts they inhibited this PAF activity. Neutral lipids of both sea bass and gilthead sea bream contained only PAF antagonists while the polar lipid fractions contained both PAF antagonists and agonists. Total lipids of sea bass exhibited stronger PAF-like activity than did those of gilthead sea bream; however, neutral lipids of sea bass contained stronger PAF antagonists than did gilthead sea bream.     

In Vitro Assessment of Probiotic Properties of Lactobacillus Strains from Infant Gut Microflora

Lactobacillus isolates from infant feces were identified and investigated in vitro for their probiotic properties. The isolates belonged to the species L. acidophilus, L. rhamnosus, L. paracasei subsp. paracasei, L. fermentum, L. delbrueckii subsp. delbrueckii, L. cellobiosus, L. plantarum, L. brevis and L. crispatus. The strains were examined for acid and bile tolerance, adhesion to Caco-2 cells, antibiotic susceptibility and antimicrobial activity against selected enteric pathogens. According to the obtained results, a L. deblueckii subsp. delbrueckii strain was found to exhibit probiotic properties. Other strains from L. paracasei subsp. paracasei and L. fermentum group also could be further investigated as potential probiotic candidates.