The false positive effect of residue of sulphur sources on dithiocarbamate analysis based on CS2 measurement

Turkey plays an important role in the international trade of apricots as it has the largest production rate in the world. Since the sulphurisation process is allowed to be used for different products, the effect of residual sulphur and its compounds (which can be found in products as pesticide residues or additive residues) on the positive detection of carbon disulphide (CS₂) still creates a big challenge in international trade. Therefore, the main objective of the present study was to investigate the effects of residues of sulphur or sulphur compounds on dithiocarbamate analysis methods based on CS₂ measurement. In this study, apricots were chosen since they contain sulphur residues as a result of the sulphurisation process. Sulphur dioxide and dithiocarbamate analyses were conducted on dried apricots prepared with the sulphurisation process (SA) and without the sulphurisation process (NSA); analysis was by two different accredited laboratories. No of pesticide was applied to either SA or NSA samples. Although some of the NSA samples had <LOQ values, approximately 70 ± 32 mg/kg SO₂ and 0.061 ± 0.021 mg/kg dithiocarbamate were detected for NSA samples. On the other hand, for the SA sample group, 927–2915 mg/kg of SO₂ and 0.265–0.825 mg/kg of dithiocarbamate were detected. Furthermore, a strong correlation between residual sulphur and dithiocarbamate values was observed. This study showed that the analysis method based on CS₂ measurement may lead to false positive results for dithiocarbamates when residues of sulphur or sulphur compounds are found in products as pesticide or additive residues. Therefore, residual sulphur compounds as a result of the sulphurisation process (which is not considered during the evaluation of products) must be taken into account during the evaluation of products for dithiocarbamates.     

Dry eye and Meibomian gland dysfunction with meibography in patients with lamellar ichthyosis

Purpose

To evaluate the dry eye findings and Meibomian gland dysfunction as demonstrated with meibography in patients with lamellar ichthyosis.

Pilot study on lower nitrosamine smokeless tobacco products compared with medicinal nicotine.

Smokeless tobacco (ST) products have the potential to be used as a harm reduction method for cigarette smokers. These products can deliver significantly less toxicants than cigarettes, although they are not toxicant free nor harmless. It is important to examine potential health risks and benefits of these products. These two small pilot studies examined the effects of two different ST products (Exalt and Ariva) compared with medicinal nicotine, another potential harm reduction product. Dependent, healthy adult cigarette smokers, who were motivated to quit smoking, underwent 1 week of baseline smoking measurement. They were then asked to quit smoking and were randomly assigned to use either an ST product or a medicinal nicotine lozenge (MNL, Commit) for 2 weeks, then crossed over to use the other product for 2 weeks. In the last week, following the sampling phase, subjects could choose the product they wished to use. Assessments were made repeatedly during baseline cigarette use and throughout the 5 weeks of treatment. Outcome measures included biomarkers for tobacco exposure and subjective, physiological, and behavioral responses. Tobacco-specific carcinogen uptake was greater from Exalt than from the MNL, and was comparable between the MNL and Ariva. Physiological effects and subjective effects on withdrawal and craving were comparable among Exalt, Ariva, and the MNL. Ariva was preferred over the MNL, which was preferred over Exalt. With the exception of medicinal nicotine products, low-nitrosamine ST products have the greatest potential to result in reduced toxicant exposure compared with other combustible reduced exposure products and have promise for reducing individual risk for disease. However, the population effect of marketing of such products as reduced exposure/reduced risk is unknown. The need for further research in this area and regulation of tobacco products is evident.     

Polymeric nanopore membranes for hydrophobicity-based separations by conformal initiated chemical vapor deposition

High-aspect ratio hydrophobic, cylindrical nanopores having diameters as low as 5 nm are rapidly fabricated using conformal vapor deposition of fluorinated polymeric layers into porous track-etched polycarbonate membranes. The resultant selectivity of these membranes for pairs of small molecules of similar size, but of different hydrophobicity, arises from solute-pore wall interactions emphasized by confinement. Increasing selectivity was observed as pore diameter decreased and as the surface of the pore became more hydrophobic. Cylindrical pores provided higher selectivity than bottleneck-shaped pores having the same minimum diameter. A maximum selectivity of 234 was achieved between mesitylene and phloroglucinol by the best performing membrane. Membranes with small fluorinated pores exhibited an effective cutoff based on the polar surface area of the molecules, with limited correlation with solute size. This technology could lead to a new generation of membrane separations based on specific interactions.     

Effect of alkali metal hydroxides on the morphological development and optical properties of ceria nanocubes under hydrothermal conditions

Nanocrystalline cerium(LV) oxide (CeO2, ceria) particles were produced via the hydrothermal treatment of cerium nitrate hexahydrate with various alkali metal hydroxides (MOH: M = Li, Na, K). Experimental conditions such as [MOH], reaction temperature, and reaction time were studied. Particle morphology as well as size of crystallites was precisely controlled by choice of experimental conditions. While rod-shaped particles were obtained at 120 degrees C, well-defined nanocubes were formed at higher temperatures regardless of the choice of MOH. Examination of particle growth kinetics, in the final stages of crystallization, showed that particle growth rate is controlled by two different mechanisms. Grain boundary diffusion controls the particle growth in the presence of NaOH with an activation energy of 113.8 kj/mol and surface diffusion for LiOH ad KOH with the activation energy of 43.0-150.9 kj/mol, respectively. In addition, the particles exhibit strong violet and blue emissions at 400 nm and 370 nm. The former emission originates from excitation of a wide band gap of CeO2. The latter one is attributed to the trivalency of the cerium ion and appears to be sensitive to all the experimental conditions studied. Both extending reaction time and increasing temperature reduce the intensity of the 370 nm emission and increase the intensity of the 400 nm emission.     

Turing Test: 50 Years Later

The Turing Test is one of the most disputed topics in artificial intelligence, philosophy of mind, and cognitive science. This paper is a review of the past 50 years of the Turing Test. Philosophical debates, practical developments and repercussions in related disciplines are all covered. We discuss Turing's ideas in detail and present the important comments that have been made on them. Within this context, behaviorism, consciousness, the `other minds' problem, and similar topics in philosophy of mind are discussed. We also cover the sociological and psychological aspects of the Turing Test. Finally, we look at the current situation and analyze programs that have been developed with the aim of passing the Turing Test. We conclude that the Turing Test has been, and will continue to be, an influential and controversial topic.     

Values of k for Slab on Winkler Foundation

Using nondimensional parameters for the analysis of a slab on a layered soil medium, a method is developed to evaluate an equivalent modulus of subgrade reaction k to be used in the Winkler model. Here, a constant value of Poisson's ratio for the soil, νs = 0.25 is used. Graphs are provided from which an equivalent value of k can be computed as soon as the complete geometry and the properties of the overall system are known. Numerical examples are given to show the comparisons of results from the equivalent Winkler k parameter with those from a modified Vlasov model and by using the value of k suggested by Biot and Vesic.     

Regulating the interpersonal self: Strategic self-regulation for coping with rejection sensitivity.

People high in rejection sensitivity (RS) anxiously expect rejection and are at risk for interpersonal and personal distress. Two studies examined the role of self-regulation through strategic attention deployment in moderating the link between RS and maladaptive outcomes. Self-regulation was assessed by the delay of gratification (DG) paradigm in childhood. In Study 1, preschoolers from the Stanford University community who participated in the DG paradigm were assessed 20 years later. Study 2 assessed low-income, minority middle school children on comparable measures. DG ability buffered high-RS people from interpersonal difficulties (aggression, peer rejection) and diminished well-being (e.g., low self-worth, higher drug use). The protective effect of DG ability on high-RS children's self-worth is explained by reduced interpersonal problems. Attentional mechanisms underlying the interaction between RS and strategic self-regulation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Robert B. Horn (illustrator), Jeff Yoshimi,Mark Deering,Russ McBride,David Fleischman (illustrator), Thierry DiDonna (illustrator), Jennifer Wedel (Editor), Mapping Great Debates. Can Computers Think?: 7 Maps and a Handbook.

Minds and Machines -