166 research outputs found

    Anselm and Russell

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    In his paper “St. Anselm’s ontological argument succumbs to Russell’s paradox” Christopher Viger presents a critique of Anselm’s Argument from the second chapter of Proslogion. Viger claims there that he manages to show that the greater than relation that Anselm used in his proof leads to inconsistency. I argue firstly, that Viger does not show what he maintains to show, secondly, that the flaw is not in the nature of Anselm’s reasoning but in Viger’s (mis)understanding of Anselm as well as in Viger’s (mis)application of some set-theoretical notions. I also describe some features of Anselmian greater than relation, which indeed plays a crucial role in his Ontological Argument. Last but not least, I present the Argument itself

    Fabrication and characterization of a tubular solid oxide fuel cell with impregnated perovskite electrodes

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    The authors would like to acknowledge the EPSRC and the University of St Andrews for funding this work.The tubular cells were produced by a simple and inexpensive method, suitable for mass production. A porous YSZ backbone was co-cast with a thin layer of YSZ electrolyte over it. After rolling in tubular shape and co-sintering, the porous backbone was impregnated with functional perovskite materials, the nickel doped lanthanum calcium titanate LCNT (La0.43Ca0.37Ni0.06Ti0.94O3- γ) for the fuel side and the lanthanum strontium ferrite LSF (La0.8Sr0.2FeO3) for the air electrode. The LCNT perovskite was proposed as the alternative fuel electrode due to its mixed ionic and electronic conductivity (MIEC) properties and catalytical activity supplemented by exsolved Ni nanoparticles. The electrochemical poling at high potential, so-called 'switching', can increase the activity of LCNT due to facilitated reduction and exsolution. After switching at 2.1 V for 2 min, the tubular cell performance in fuel cell mode increased threefold. The impedance analysis indicated a reduction of ohmic and polarisation resistance on the whole frequency range and facilitated electrode kinetics under applied voltage.PostprintPeer reviewe

    A novel solid oxide electrochemical oxygen pump for oxygen therapy

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    The authors would like to acknowledge the Scottish Funding Council for support this work and EPSRC for the Scios and EM equipment (EP/L017008/1, EP/T019298/1).A solid oxide electrochemical oxygen pump was developed in tubular geometry with YSZ electrolyte and LSCF/CGO symmetrical air electrodes. The cells were manufactured based on green symmetrical porous YSZ electrode backbones cast on the green YSZ electrolyte tape, rolled into tubular geometry, co-sintered and impregnated with functional materials. The prepared cell had a thin 16 μm-electrolyte and supporting 76 μm-symmetric electrodes. At 700 °C, 2.8 A current (0.8 A cm−2) was obtained under 0.5 V in the single tubular cell infiltrated with 30% CGO and 45% LSCF. A four cell bundle produced theoretical 1.82 l hr−1 O2 with a power consumption of 2.18 W at 700 °C. Excellent stability of the cells was achieved during severe current and thermal cycling tests, indicating the successful fabrication of the tubular cells using the tape co-casting method.Publisher PDFPeer reviewe

    Nephrotic syndrome unfavorable course correlates with downregulation of podocyte vascular endothelial growth factor receptor (VEGFR)-2

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    Idiopathic nephrotic syndrome (INS) in children is most commonly caused by primary glomerulopathies. Morphological lesions observed in INS might be secondary to inflammatory factors of mainly extra-renal origin. The vascular endothelial growth factor (VEGF) family is regarded as playing a crucial role in this pathomechanism. The aim of the present work was to analyze the possible relation between VEGF-C and VEGF receptor (VEGFR)-2 expressions at electron microscopy level in different INS cases. The study group comprised 18 children with minimal change disease (MCD), 30 patients diagnosed with diffuse mesangial proliferation (DMP) and 11 subjects with focal segmental glomerulosclerosis (FSGS). An indirect immunohistochemical assay employing monoclonal anti-VEGF-C and anti-VEGFR-2 antibodies was applied in the study. The immunohistochemical expression of VEGF-C within podocyte cytoplasm was significantly increased in DMP subjects who were resistant to steroids and in all FSGS patients compared to MCD children and controls (p < 0.05). VEGF-C over-expression in these cases was followed by downregulation of VEGFR-2. Nephrotic syndrome progression correlates with the downregulation of podocyte VEGFR-2. For this reason, decreased VEGFR-2 expression in the podocyte processes of children with idiopathic nephrotic syndrome might be regarded as a potent factor of unfavorable prognosis. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 3, pp. 472&#8211;478

    Local populations of endangered Maculinea (Phengaris) butterflies are flood resistant

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    Semi-natural wet meadows are threatened by drainage, the abandonment of traditional management and climate change. The large blue butterflies Maculinea teleius and M. nausithous are flagship species associated with wet meadows and are the targets of many conservation programmes. However, there is little knowledge on the impact of natural catastrophes, such as floods, on the persistence of these butterflies. In our study we tested how a flood that resulted in the temporary inundation of meadows affected populations of M. teleius and M. nausithous. Studies were conducted in two consecutive seasons of 2009 (with ‘normal’ weather) and 2010 (with extreme rainfall and a consequent flood in May) in a wet meadow complex located in the Vistula River valley in southern Poland. In both years the abundance of adults was estimated for each local habitat patch (n = 55) within sympatric metapopulations of both species. Additionally, in June 2010, i.e. directly after the flood and shortly before the flight period, a total of 754 Myrmica ant nests in 10 habitat patches (6 inundated vs. 4 not inundated) were checked for the presence of Maculinea larvae and pupae. We found no impact of inundation on year-to-year changes in adult population sizes. The probability of occurrence of Maculinea larvae and pupae in ant nests was higher in temporarily inundated meadows. Our results indicate that temporary inundation occurring after long-term downpours does not negatively affect the investigated species even during the larval period in ant nests at ground level. This provides an argument against drainage works in wet meadows with Maculinea butterflies

    Oxidative/antioxidative status in patients after myocardial infarction and in those without cardiovascular event depending on anthropometric factors defining body weight

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    Obesity is one of the factors leading to the development of atherosclerosis. This metabolic disorder is associated with an increased production of reactive oxygen species, which affect the oxidative stress levels. The aim of this study was to evaluate oxidative/antioxidative status and to investigate the correlation between redox markers and anthropometric parameters and body composition in adult patients after myocardial infarction and in individuals without a cardiovascular event in the past. Descriptive data on socio-demographic, clinical, and anthropometric features and blood samples were collected and categorized into two equal groups: after myocardial infarction (study group (SG), n = 80) and without a cardiovascular event (control group (CG), n = 80). The oxidative/antioxidative status was assessed in plasma on the basis of total oxidative/capacitive status (PerOx), total antioxidative status/capacity (ImAnOx), and oxidized low-density lipoprotein (oxLDL). The oxLDL was significantly higher in the CG group compared to the SG group (p = 0.02). No significant differences were found with regard to PerOx and ImAnOx values between the groups studied. A significant positive correlation between PerOx and percentage of adipose tissue (FM%) and body adiposity index (BAI) was found in the two studied groups. ImAnOx significantly positively correlated with visceral adiposity indexes(VAIs) in SG and FM% in CG. OxLDL negatively correlated with body mass index and waist to hip circumference ratio in CG. The total oxidative/antioxidative status is related to the amount of adipose tissue and the BAIs of the subjects. It was observed that it correlates more frequently with the visceral distribution of body fat
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