Dispersive liquid–liquid microextraction for the determination of organochlorine pesticides residues in honey by gas chromatography-electron capture and ion trap mass spectrometric detection

A simple dispersive liquid–liquid microextraction (DLLME) protocol for the determination of 15 organochlorine pesticides residues in honey is proposed. The selected pesticides were separated using gas chromatography and detected by electron capture (ECD) or ion trap mass spectrometry (GC-IT/MS). Several parameters affecting the extraction efficiency namely type and volume of organic extraction solvent, type and volume of disperser solvent, sample pH, ionic strength, extraction time and centrifugation speed were systematically investigated. The final DLLME protocol involved the addition of 750 μL acetonitrile (disperser) and 50 μL chloroform (extraction solvent) into a 5 mL aqueous honey solution followed by centrifugation. The sedimented organic phase (chloroform) were analysed directly by GC-IT/MS or evaporated and reconstituted in acetonitrile prior to the GC-ECD analysis. The analytical performance of the GC-ECD and GC-IT/MS methods was compared and discussed. Under the selected experimental conditions, the enrichment factors varied between of 36 and 114. The limits of detection (LOD) were in the range of 0.02–0.15 μg L⁻¹ (0.4–3 ng g⁻¹) for GC-ECD and 0.01–0.2 μg L⁻¹ (0.2–4 ng g⁻¹) for GC-IT/MS which is adequate to verify compliance of products to legal tolerances. The proposed method was applied to the analysis of the selected organochlorine pesticides residues in various honey samples obtained from Greek region. Mean recoveries were ranged from 75% to 119% while the precision was better than 20% in both methodologies.     

The interplay of online shopping motivations and experiential factors on personalized e-commerce: A complexity theory approach

The present study aims to examine purchase behavior in personalized online shopping by employing complexity theory, based on customers’ online shopping experience and online shopping motivations. To address its objectives, a conceptual model is proposed along with research propositions. The research propositions are validated through a survey on 401 customers’ experience with online shopping, by using the data analysis tool fsQCA (fuzzy-set Qualitative Comparative Analysis). The results, indicate nine configurations of online shopping experience and online shopping motivations that lead to high purchase intentions. This study takes a step further the literature of online shopping and the theoretical ground of how customers’ online shopping experience combines with their online shopping motivations in order to predict and explain increased intention to purchase. The findings offer implications for both researchers and online retailers, regarding the development of new theories in personalized e-commerce and the provision of personalized services.     

Variation of the physicochemical properties diesel-biodiesel blends – range 0–100%

Recently biodiesel has become more attractive because it is made from renewable resources. In this study we demonstrate how the proportion of diesel/biodiesel blends determines the qualitative parameters and energy efficiency of the final product. The use of biodiesel in blends with conventional diesel is becoming more and more valuable, based on European directive for use up to 20% biodiesel by 2020. We came to the conclusion that mixtures up 30% Biodiesel gives product within diesel specification limits which is suitable for commercial use. This methodology can be a manual for the production line of mixtures for commercial use.     

Fiscal Policy Design in Greece in the Aftermath of the Crisis: An Algorithmic Approach

We present a computational approach to the design of fiscal policy that is based on algorithmic, linear feedback control methods. In particular, in the context of a linear, deterministic macro-model, we develop an algorithmic procedure which allows us to design fiscal policy rules for government expenditures so that desired target-levels for GDP are exactly met (that is, complete tracking is achieved). In order to examine the effectiveness of our method we estimate the model for the Greek economy and run some counterfactual policy experiments. These experiments indicate that, for the Greek economy in the beginning of the crisis in early 2010, expansionary fiscal policy would have been able to stimulate growth and reduce the debt-to-GDP ratio.     

Development of a fast,lean and agile direct pelletization process using experimental design techniques

A novel hot melt direct pelletization method was developed, characterized and optimized, using statistical thinking and experimental design tools. Mixtures of carnauba wax (CW) and HPMC K100M were spheronized using melted gelucire 50–13 as a binding material (BM). Experimentation was performed sequentially; a fractional factorial design was set up initially to screen the factors affecting the process, namely spray rate, quantity of BM, rotor speed, type of rotor disk, lubricant–glidant presence, additional spheronization time, powder feeding rate and quantity. From the eight factors assessed, three were further studied during process optimization (spray rate, quantity of BM and powder feeding rate), at different ratios of the solid mixture of CW and HPMC K100M. The study demonstrated that the novel hot melt process is fast, efficient, reproducible and predictable. Therefore, it can be adopted in a lean and agile manufacturing setting for the production of flexible pellet dosage forms with various release rates easily customized between immediate and modified delivery.     

Sharp Phylogeographic Breaks and Patterns of Genealogical Concordance in the Brine Shrimp Artemia franciscana

Genealogical concordance is a critical overlay of all phylogenetic analyses, irrespective of taxonomic level. To assess such patterns of congruence we have compiled and derived sequence data for two mitochondrial (16S rRNA, COI) and two nuclear (ITS1, p26) markers in 14 American populations of the hypersaline branchiopod Artemia franciscana. Cladistic analysis revealed three reciprocally monophyletic mitochondrial clades. For nuclear DNA, incomplete lineage sorting was evident presumably as a result of slower coalescence or male-mediated dispersal. Our findings capture the genealogical interval between gene splitting and population divergence. In this sense, strong indications are provided in favour of a superspecies status and ongoing speciation in A. franciscana.     

Distribution of plasminogen activator forms in different fractions of buffalo milk

Neuronal growth cones, the sensory-motile structures at the tips of developing axons, navigate to their targets over distances that can be many times greater than their diameter. They may accomplish this impressive task by following spatial gradients of axon guidance molecules in their environment (Bonhoeffer & Gierer, 1984; Tessier-Lavigne & Placzek, 1991; Baier & Bonhoeffer, 1994). We calculate the optimal shape of a gradient and the distance over which it can be detected by a growth cone for two competing mechanistic models of axon guidance. The results are surprisingly simple: Regardless of the mechanism, the maximum distance is about 1 cm. Since gradients and growth cones have coevolved, we suggest that the shape of the gradient in situ will predict the mechanism of gradient detection. In addition, we show that the experimentally determined dissociation constants for receptor-ligand complexes implicated in axon guidance are about optimal with respect to maximizing guidance distance. The relevance of these results to the retinotectal system is discussed.     

Effects of Chios mastic gum and exercise on physical characteristics,blood lipid markers,insulin resistance,and hepatic function in healthy Japanese men

The effects of Chios mastic gum (Pistacia lentiscus var. Chia) and exercise on physical characteristics, blood lipid markers, insulin resistance, and hepatic function were investigated in healthy, non-smoking Japanese men aged ≥ 40 years. Participants were allocated to control (C, 5 g/day placebo powder, n = 7), mastic (M, 5 g/day mastic powder, n = 7), or mastic plus physical activity groups (M + PA, 5 g/day mastic powder and 30-min exercise three times/week, n = 7), and measurements were taken at baseline, 3 and 6 months. Serum triglycerides were significantly reduced at 3 months in M and M + PA compared with C (P < 0.05). Serum insulin and homeostatic model assessment of insulin resistance values were significantly reduced at 3 and 6 months in M + PA, and at 6 months in M, compared with C (P < 0.05). These results indicate that Chios mastic gum intake for 6 months reduced serum triglyceride and insulin concentrations, and additional exercise enhanced the effect on insulin.     

The effect of hydrocooling on ripening related quality attributes and cell wall physicochemical properties of sweet cherry fruit (Prunus avium L.)

The aim of this study was to evaluate the effect of hydrocooling, as a precooling treatment, on ripening related parameters of two sweet cherry cultivars (Prunus avium L. cvs. ‘Tragana Edessis’, ‘Mpakirtzeika’) after 1-week cold storage (0 °C, 95% R.H.). Results indicated that hydrocooling delayed the deterioration and senescence of cherry fruit, maintaining a higher quality, as indicated by reduced stem browning and surface shrivelling. In particular, hydrocooled ‘Tragana Edessis’ fruit showed considerably less stem browning (14.6–29.6%), while the benefits of hydrocooling were less pronounced in ‘Mpakirtzeika’ fruit. Other quality attributes, such as cracking, decay, external color and soluble solids content were not affected by hydrocooling. Furthermore cell wall properties, as indicated by uronic acid and neutral sugars content in cell wall material extracted from the cherry fruits, were slightly or not affected by the hydrocooling process. Overall, the present study showed that cherry fruit subjected to hydrocooling followed by 1 week's storage at 0 °C and 95% R.H. retained their quality for a further 3 days at room temperature, but after 5 days at room temperature many of the fruit were of unacceptable quality.