A Top Dog Tale with Preference Complementarities

The emergence of a winner-take-all (top dog) outcome is generally due to political or institutional constraints or to specific technological features which favour the performance of just one individual. In this paper we provide a different explanation for the occurrence of a top-dog equilibrium in exchange economies. We show that once heterogeneous complementarities (i.e. Scarf’s preferences) are analysed with general endowment distributions, a variety of equilibria different from the well-known symmetric outcome with full utilisation of resources can emerge. Specifically, we show that stable corner equilibria with a winner-take-all (top dog) individual arise that are Pareto optima although the remaining individuals are no better off than with zero consumption and resources can be unused. Because of heterogenous complementarities, market mechanisms are weak and cannot overcome the top dog’s power. Voting mechanisms or taxation policies can reduce the top dog’s privileged position

A Novel DC Therapy with Manipulation of MKK6 Gene on Nickel Allergy in Mice

BACKGROUND: Although the activation of dermal dendritic cells (DCs) or Langerhans cells (LCs) via p38 mitogen-activated protein kinase (MAPK) plays a crucial role in the pathogenesis of metal allergy, the in vivo molecular mechanisms have not been identified and a possible therapeutic strategy using the control of dermal DCs or LCs has not been established. In this study, we focused on dermal DCs to define the in vivo mechanisms of metal allergy pathogenesis in a mouse nickel (Ni) allergy model. The effects of DC therapy on Ni allergic responses were also investigated. METHODS AND FINDING: The activation of dermal DCs via p38 MAPK triggered a T cell-mediated allergic immune response in this model. In the MAPK signaling cascade in DCs, Ni potently phosphorylated MAP kinase kinase 6 (MKK6) following increased DC activation. Ni-stimulated DCs could prime T cell activation to induce Ni allergy. Interestingly, when MKK6 gene-transfected DCs were transferred into the model mice, a more pronounced allergic reaction was observed. In addition, injection of short interfering (si) RNA targeting the MKK6 gene protected against a hypersensitivity reaction after Ni immunization. The cooperative action between T cell activation and MKK6-mediated DC activation by Ni played an important role in the development of Ni allergy. CONCLUSIONS: DC activation by Ni played an important role in the development of Ni allergy. Manipulating the MKK6 gene in DCs may be a good therapeutic strategy for dermal Ni allergy

Alterations on phenolic compounds and antioxidant activity during sour grape juice concentrate processing

The alterations of phenolic compounds and antioxidant capacity of sour grape juice were investigated during the concentration process stages. Phenolics and antioxidant properties of the samples changed more at the vacuum evaporation stage than that of the other stages. After evaporation, the antioxidant capacity of the samples decreased approximately between 14.2 and 17.0 % for DPPH and ABTS methods, respectively. Besides, phenolic contents also decreased approximately as 14.8%. HPLC data on phenolics of sour grape juice during concentrate processing gave 12 polyphenols, including gallic acid, (+)-catechin, (-)-epigallocatechin, vanillic acid, (-)-epigallocatechin gallate, (-)-epicatechin, caftaric acid, caffeic acid and p-coumaric acid, which were determined as 1.05-1.83 mg/100 g, 5.40-7.83 mg/100 g, 6.35-9.21 mg/100 g, 3.01-5.18 mg/100 g, 0- 1.95 mg/100 g, 2.33-3.54 mg/100 g, 12.40-37.60 mg/100 g, 1.44-2.26 mg/100 g and 0.27-0.44 mg/100 g, respectively. Ferulic, sinapic acids and quercetin were only detected at concentrate step of the sour grape juice processing and were found as 0.18 mg/100 g, 0.28 mg/100 g and 0.76 mg/100 g, respectively. © 2018, Ciência Téc. Vitiv. As alterações dos compostos fenólicos e da capacidade antioxidante do sumo de uvas não amadurecidas foram investigadas durante as etapas do processo de concentração. Os compostos fenólicos e as propriedades antioxidantes das amostras sofreram maior alteração na fase de evaporação sob vácuo do que nas restantes fases. Após a evaporação, a capacidade antioxidante das amostras diminuiu aproximadamente entre 14.2 e 17.0% nas determinações efetuadas pelos métodos DPPH e ABTS, respetivamente. Por outro lado, os teores de compostos fenólicos também diminuiram aproximadamente 14.8%. Os resultados obtidos por HPLC revelaram a presença de 12 polifenóis, incluindo ácido gálhico, (+)-catequina, (-)- epigalhocatequina, ácido vanílico, (-)-epigalhocatequina galhato, (-)-epicatequina, ácido caftárico, ácido cafeico e ácido p-cumárico, com teores de 1.05-1.83 mg/100 g, 5.40-7.83 mg/100 g, 6.35-9.21 mg/100 g, 3.01-5.18 mg/100 g, 0-1.95 mg/100 g, 2.33-3.54 mg/100 g, 12.40-37.60 mg/100 g, 1.44-2.26 mg/100 g e 0.27-0.44 mg/100 g, respetivamente. Os ácidos ferúlico e sinápico e a quercetina foram detetados somente na etapa de concentração do sumo de uvas não amadurecidas, com teores de 0.18 mg/100 g, 0.28 mg/100 g e 0.76 mg/100 g, respetivamente. © 2018, Ciência Téc. Vitiv

Extraction of Bioactive Compounds from Milled Grape Canes (Vitis vinifera) Using a Pressurized Low-Polarity Water Extractor

Trans-resveratrol and trans-epsilon-viniferin were extracted from milled grape canes using pressurized low-polarity water. The effects of temperature were significant for both compounds (p a parts per thousand currency signaEuro parts per thousand 0.05): extraction at 160 A degrees C resulted in a 40% loss of trans-resveratrol compared to 95 A degrees C while reduction of trans-epsilon-viniferin at both temperatures remained at 30%. Increasing ethanol concentration from 0% to 25% increased the extraction of total phenolics and trans-epsilon-viniferin by 44% and 489%, respectively. Solvent flow rate also influenced trans-epsilon-viniferin extraction. Antioxidant activity showed a strong correlation with total phenolic content of the extracts, and the two target phenolic compounds. Except for the modifier concentration, the extraction parameters studied were not statistically significant with respect to the antioxidant activity of extracts (p > 0.05). Effective diffusivities of trans-resveratrol multiplied from 3.3 x 10(-11) to 10.4 x 10(-11) m(2)/s by three times with increasing temperature. The modified Gompertz equation satisfactorily explained the extraction of the stilbenes investigated

MODELING SOLID-LIQUID EXTRACTION KINETICS OF TRANS-RESVERATROL AND TRANS-e-VINIFERIN FROM GRAPE CANE

Solidliquid extraction of resveratrol and viniferin from grape cane samples was described by using first-order kinetic model, Peleg's model, two-site kinetic model and modified Gompertz equation. Goodness of fits of the models were evaluated by comparing the adjusted determination coefficient and root mean square error and mean percentage error values. Although the two-site kinetic model with four parameters described the data better, Peleg's model, with only two parameters, could explain the data with a slight loss of goodness of fit. The modified Gompertz equation showed the worst performance for describing the solidliquid extraction of stilbenes. PRACTICAL APPLICATIONS The present study introduces the comparison of well-known models applied to explain extraction kinetic of stilbene compounds of grape cane and to determine the best model with its justifications. Mathematical models provide information about the system and/or process to which they are applied. In design and/or process application stages, any information about that process and/or system has crucial importance because in the decision stages, this know-how helps the designers and researchers find the best design parameters and the most effective process conditions to optimize purposes. Mathematical models are accepted as the most economical ways for these purposes

Towards a Leadless Cardiac Multisite Pacemaker System

Introduction Recently, leadless pacemakers have been introduced to overcome the drawbacks associated with pacemaker leads. However, these leadless pacemakers are single-chamber systems, although dual-chamber or even multisite pacing would provide a more physiologic myocardial excitation. We aim at developing a leadless multisite pacemaker system, featuring several single leadless pacemakers (e.g. one in the right atrium and one in the right ventricle) that communicate wirelessly with each other. To retain the pacemakers’ longevity, it is crucial that the communication method is power efficient (modern pacemakers consume only 5-10 µW of power). Method We implemented conductive intra body communication (IBC) into a leadless multisite pacemaker system. IBC makes use of the electrical conductivity of tissue, i.e. uses the myocardium as signal carrier. In a first step, we electrically characterized the myocardium of porcine hearts by performing in-vivo and in-vitro impedance measurements in the frequency range from 10 kHz to 18 MHz. Based on the resulting transfer function, we developed prototypes of communication modules that are optimized for communication via the myocardial tissue. Results The developed leadless communication modules feature multisite pacing and are capable of performing continuous bidirectional communication between the atrium and the ventricle. The functionality of the modules was tested in-vitro and in-vivo on porcine hearts. The lowest damping of the communication signal (15-25 dB) was obtained at frequencies between 500 kHz and 2 MHz. Less than 1 µW of average power was dissipated into the tissue for synchronization. Conclusion We showed the potential of a low-power leadless communication method suitable for leadless pacemakers. By integrating this technique into leadless pacemakers, it may be possible to build a leadless multisite pacemaker system