The effects of growing conditions on oil content, fatty acid composition and tocopherol content of some sunflower varieties produced in Turkey

The properties of some extensively cultivated sunflower seed varieties in Turkey and their oils were investigated. 1991-1992 crop year sunflower varieties harvested from Trakya University, Tekirdag Agricultural Faculty, Experiment field of Crop Science Department were used as research materials. The oil content, fatty acid composition and tocopherol content of sunflower seeds in 1991 and 1992 crop years were determined as 44.2-51.2% (on dry weight basis), 43.0-51.5% (on dry weight basis); oleic acid 14.8-18.5%, 32.9-40.1%; linoleic acid 69.5-74.5%, 49.7-55.7% and tocopherol content (as alpha-tocopherol) 648-860 mg/kg, 524-880 mg/kg, respectively. It was determined that the growing conditions significantly affected the fatty acid compositions of sunflower varieties studied. While the oleic acid content of the 1992 crop increased, the linoleic acid content of the same crop decreased compared to the 1991 crop.     

In vitro Action of Pancreatic Lipase on Complex Glycerides from Thermally Oxidized Oils

The action of pancreatic lipase on complex glyceridic molecules originating during thermal oxidation of fats is defined. Four samples of increasing level of alteration compounds – 4.5, 37.1, 67.2 and 100% respectively – have been analyzed by means of a combination of chromatographic techniques, which allows quantification of the most representative groups of degradation compounds – oxidized triacylglycerol monomers, triacylglycerol dimers and polymers, diacylglycerols and fatty acids. The samples have been subjected to in vitro hydrolysis by pancreatic lipase at different reaction times and modifications originated have been defined by means of high performance size exclusion chromatography (HPSEC) as well as by titration of fatty acids released. The results clearly demonstrate that enzymatic hydrolysis depends on the molecular weight of the glycerides being slower as alteration compound weight increases. Moreover, by direct quantitation of complex glycerides remaining after the action of the enzyme, the influence of different variables (reaction time, alteration level, etc) can be deduced.     

Learning differential diagnosis of erythemato-squamous diseases using voting feature intervals

A new classification algorithm, called VFI5 (for Voting Feature Intervals), is developed and applied to problem of differential diagnosis of erythemato-squamous diseases. The domain contains records of patients with known diagnosis. Given a training set of such records, the VFI5 classifier learns how to differentiate a new case in the domain. VFI5 represents a concept in the form of feature intervals on each feature dimension separately. classification in the VFI5 algorithm is based on a real-valued voting. Each feature equally participates in the voting process and the class that receives the maximum amount of votes is declared to be the predicted class. The performance of the VFI5 classifier is evaluated empirically in terms of classification accuracy and running time.     

Varix of the vortex vein ampulla simulating choroidal melanoma: report of four cases

Increasing evidence demonstrates that ultraviolet A radiation (UVA) contributes to photoaging, which results in the accumulation of massive amounts of abnormal elastic material in the dermis of photoaged skin. To study UVA-induced photoaging in an in vivo system, we utilized a line of transgenic mice containing the human elastin promoter linked to a chloramphenicol acetyl transferase reporter gene. Our prior work demonstrates promoter activation in response to ultraviolet B radiation (UVB), UVA, and psoralen plus ultraviolet A radiation in the skin of these mice. The addition of psoralen (8-MOP) prior to administration of UVA results in substantial increases in promoter activation, as compared with UVA alone. To demonstrate the utility of these mice as a model of UVA-induced photodamage, we administered four lotions to the skin of our transgenic mice that included: a sunscreen containing octyl methoxycinnamate and benzophenone-3 with a sun protection factor (SPF) of 15, the UVA filter butyl methoxydibenzoylmethane, the SPF 15 sunscreen and the UVA filter together, and the lotion vehicle alone. Following sunscreen administration, mice received a single psoralen plus ultraviolet A radiation treatment. All sunscreens decreased chloramphenicol acetyl transferase activity with the SPF 15 sunscreen, the UVA filter, and the combination SPF 15 sunscreen and UVA filter, resulting in increasing degrees of protection against psoralen plus ultraviolet A radiation. These results demonstrate that this model functions as a rapid and sensitive model of UVA photodamage for the identification and comparison of compounds that protect against UVA-induced photoaging.     

Dislocation etch pits and growth of arsenic-antimony single crystals

Single crystals of an arsenic-antimony solid solution have been grown at the minimum melting point (612‡C) composition (25.5 at.% arsenic) where the solidus and liquidus touch. Pyramidal etch pits produced on (111) cleavage faces mark the sites of emergence of dislocations; dislocation densities are low, ranging between 10³ and 10⁵ per cm². The relationship between an unambiguous, right handed axial set and etch pit orientation on the (111) surface is established. The permissible Burgers vectors and dislocation reactions are detailed and are related to the observed etch pit types. In general, the results obtained also apply to the A7 structure elements themselves and amend previous findings of the crystallographic relationships between dislocation directions and etch pits.     

Strays-insensitive switched-capacitor network realisation for nth-order voltage transfer functions

A general synthesis method is given for the realisation of nth-order voltage transfer functions in the z-domain by active SC (switched-capacitor) networks using only biphased switches, capacitors and ideal operational amplifiers. The method presented is based on signal-flow graphs and the resulting networks are completely insensitive to stray capacitances.     

Experimental activation energies for evolution of oxygen and chlorine on oxide electrodes

The chlorine and oxygen overpotential in dependence on the current density i (A cm^?2) and on the temperature in the range of 15–75°C was measured at γ-MnO₂ and β-PbO₂ electrodes in concentrated water solutions of sodium chloride and perchlorate. From the measured values the experimental activation energy in dependence on overpotential was calculated and, for the temperature of 25°C, the constants of Tafel's equation (a,b) (α, i_o respectively) were evaluated.     

Characterization of Candida albicans orthologue of the Saccharomyces cerevisiae signal-peptidase-subunit encoding gene SPC3

The Candida albicans orthologue of the SPC3 gene, which encodes one of the subunits essential for the activity of the signal peptidase complex in Saccharomyces cerevisiae, was isolated by complementation of a thermosensitive mutation in the S. cerevisiae SEC61 gene. The cloned gene (CaSPC3) encodes a putative protein of 192 amino acids that contains one potential membrane-spanning region and shares significant homology with the corresponding products from mammalian (Spc22/23p) and yeast (Spc3p) cells. CaSPC3 is essential for cell viability, since a hemizygous strain containing a single copy of CaSPC3 under control of the methionine-repressible MET3 promoter did not grow in the presence of methionine and cysteine. The cloned gene could rescue the phenotype associated with a spc3 mutation in S. cerevisiae, indicating that it is the true C. albicans orthologue of SPC3. However, in contrast with results previously described for its S. cerevisiae orthologue, CaSPC3 was not able to complement the thermosensitive growth associated with a mutation in the SEC11 gene. The heterologous complementation of the sec61 mutant suggests that Spc3p could play a role in the interaction that it is known to occur between the translocon (Sec61 complex) and the signal peptidase complex, at the endoplasmic reticulum membrane.     

Aflatoxins in pozol, a nixtamalized, maize-based food

To determine whether pozol, a nixtamalized maize-based food was contaminated with aflatoxins, samples of non-fermented pozol were collected during the period November 2002 to April 2003 from local markets at Comitan in Chiapas, Mexico. The samples were analyzed for the presence of aflatoxins. Nineteen out of one hundred and eleven samples were contaminated with aflatoxin B2 (AFB2) and traces of aflatoxin B1 (AFB1). The percentage of samples contaminated with AFB2 in pozol prepared with white maize was 5.4%. Pozol mixed with toasted cacao paste had a contamination rate of 41.5%. No aflatoxins were detected in pozol prepared with yellow maize. It was found that only 1 of 19 contaminated samples had aflatoxin concentrations above 20 ppb.