44 research outputs found

    Model of macroeconomic evolution in stable regionally dependent economic fields

    Full text link
    We develop a model for the evolution of economic entities within a geographical type of framework. On a square symmetry lattice made of three (economic) regions, firms, described by a scalar fitness, are allowed to move, adapt, merge or create spin-offs under predetermined rules, in a space and time dependent economic environment. We only consider here one timely variation of the ''external economic field condition''. For the firm fitness evolution we take into account a constraint such that the disappearance of a firm modifies the fitness of nearest neighboring ones, as in Bak-Sneppen population fitness evolution model. The concentration of firms, the averaged fitness, the regional distribution of firms, and fitness for different time moments, the number of collapsed, merged and new firms as a function of time have been recorded and are discussed. Also the asymptotic values of the number of firms present in the three regions together with their average fitness, as well as the number of respective births and collapses in the three regions are examined. It appears that a sort of criticalcritical selection pressure exists. A power law dependence, signature of self-critical organization is seen in the birth and collapse asymptotic values for a high selection pressure only. A lack of self-organization is also seen at region borders.Comment: 11 figures double columns on 7 page

    Estimation of the charge carrier localization length from Gaussian fluctuations in the magneto-thermopower of La_{0.6}Y_{0.1}Ca_{0.3}MnO_3

    Full text link
    The magneto-thermoelectric power (TEP) ΔS(T,H)\Delta S(T,H) of perovskite type manganise oxide La0.6Y0.1Ca0.3MnO3La_{0.6}Y_{0.1}Ca_{0.3}MnO_3 is found to exhibit a sharp peak at some temperature T=170KT^{*}=170K. By approximating the true shape of the measured magneto-TEP in the vicinity of TT^{*} by a linear triangle of the form ΔS(T,H)Sp(H)±B±(H)(TT)\Delta S(T,H)\simeq S_p(H)\pm B^{\pm}(H)(T^{*}-T), we observe that B(H)2B+(H)B ^{-}(H)\simeq 2B ^{+}(H). We adopt the electron localization scenario and introduce a Ginzburg-Landau (GL) type theory which incorporates the two concurrent phase transitions, viz., the paramagnetic-ferromagnetic transition at the Curie point TCT_C and the "metal-insulator" (M-I) transition at TMIT_{MI}. The latter is characterized by the divergence of the field-dependent charge carrier localization length ξ(T,H)\xi (T,H) at some characteristic field H0H_0. Calculating the average and fluctuation contributions to the total magnetization and the transport entropy related magneto-TEP ΔS(T,H)\Delta S(T,H) within the GL theory, we obtain a simple relationship between TT^{*} and the above two critical temperatures (TCT_{C} and TMIT_{MI}). The observed slope ratio B(H)/B+(H)B ^{-}(H)/B ^{+}(H) is found to be governed by the competition between the electron-spin exchange JSJS and the induced magnetic energy MsH0M_sH_0. The comparison of our data with the model predictions produce TC=195KT_{C}=195K, JS=40meVJS=40meV, M0=0.4MsM_0=0.4M_s, ξ0=10A˚\xi_0=10\AA, and ne/ni=2/3n_e/n_i=2/3 for the estimates of the Curie temperature, the exchange coupling constant, the critical magnetization, the localization length, and the free-to-localized carrier number density ratio, respectively.Comment: 6 pages (REVTEX), 2 PS figures (epsf.sty); submitted to Phys.Rev.

    Benford's law predicted digit distribution of aggregated income taxes: the surprising conformity of Italian cities and regions

    Full text link
    The yearly aggregated tax income data of all, more than 8000, Italian municipalities are analyzed for a period of five years, from 2007 to 2011, to search for conformity or not with Benford's law, a counter-intuitive phenomenon observed in large tabulated data where the occurrence of numbers having smaller initial digits is more favored than those with larger digits. This is done in anticipation that large deviations from Benford's law will be found in view of tax evasion supposedly being widespread across Italy. Contrary to expectations, we show that the overall tax income data for all these years is in excellent agreement with Benford's law. Furthermore, we also analyze the data of Calabria, Campania and Sicily, the three Italian regions known for strong presence of mafia, to see if there are any marked deviations from Benford's law. Again, we find that all yearly data sets for Calabria and Sicily agree with Benford's law whereas only the 2007 and 2008 yearly data show departures from the law for Campania. These results are again surprising in view of underground and illegal nature of economic activities of mafia which significantly contribute to tax evasion. Some hypothesis for the found conformity is presented.Comment: 18 pages, 5 tables, 4 figures, 61 references, To appear in European Physical Journal

    Permanent 125I-seed prostate brachytherapy: early prostate specific antigen value as a predictor of PSA bounce occurrence

    Get PDF
    <p>Abstract</p> <p>Purpose</p> <p>To evaluate predictive factors for PSA bounce after <sup>125</sup>I permanent seed prostate brachytherapy and identify criteria that distinguish between benign bounces and biochemical relapses.</p> <p>Materials and methods</p> <p>Men treated with exclusive permanent <sup>125</sup>I seed brachytherapy from November 1999, with at least a 36 months follow-up were included. Bounce was defined as an increase ≥ 0.2 ng/ml above the nadir, followed by a spontaneous return to the nadir. Biochemical failure (BF) was defined using the criteria of the Phoenix conference: nadir +2 ng/ml.</p> <p>Results</p> <p>198 men were included. After a median follow-up of 63.9 months, 21 patients experienced a BF, and 35.9% had at least one bounce which occurred after a median period of 17 months after implantation (4-50). Bounce amplitude was 0.6 ng/ml (0.2-5.1), and duration was 13.6 months (4.0-44.9). In 12.5%, bounce magnitude exceeded the threshold defining BF. Age at the time of treatment and high PSA level assessed at 6 weeks were significantly correlated with bounce but not with BF. Bounce patients had a higher BF free survival than the others (100% versus 92%, p = 0,007). In case of PSA increase, PSA doubling time and velocity were not significantly different between bounce and BF patients. Bounces occurred significantly earlier than relapses and than nadir + 0.2 ng/ml in BF patients (17 vs 27.8 months, p < 0.0001).</p> <p>Conclusion</p> <p>High PSA value assessed 6 weeks after brachytherapy and young age were significantly associated to a higher risk of bounces but not to BF. Long delays between brachytherapy and PSA increase are more indicative of BF.</p

    LOW-DIMENSIONAL THERMOELECTRIC-POWER OF HIGH-TEMPERATURE SUPERCONDUCTORS IN THE FLUCTUATION REGIME

    No full text
    We calculate the Aslamazov-Larkin direct contribution to the thermoelectric power of high-critical-temperature superconductors in one (1D) and two (2D) dimensions, using a kinetic formalism. This extends the results of Howson et al. limited to 3D (and that of Maki and of Varlamov and Livanov). The singular fluctuation contribution vanishes in 2D though it was expected to behave like epsilon–1 where epsilon = (T-T(c))/T(c). In 1D the superconductivity fluctuation contribution diverges like (-e-epsilon–3/2)

    Mitochondrial targeting of peroxiredoxin 5 is preserved from annelids to mammals but is absent in pig Sus scrofa domesticus.

    No full text
    Peroxiredoxin 5 (PRDX5) is a thioredoxin peroxidase able to reduce hydrogen peroxide, alkyl hydroperoxides and peroxynitrite. In human, PRDX5 was reported to be localized in the cytosol, the mitochondria, the peroxisomes and the nucleus. Mitochondrial localization results from the presence of an N-terminal mitochondrial targeting sequence (MTS). Here, we examined the conservation of mitochondrial localization of PRDX5 in animal species. We found that PRDX5 MTS is present and functional in the annelid lugworm Arenicola marina. Surprisingly, although mitochondrial targeting is well conserved among animals, PRDX5 is missing in mitochondria of domestic pig. Thus, it appears that mitochondrial targeting of PRDX5 may have been lost throughout evolution in animal species, including pig, with unknown functional consequences

    Critical behaviour of transport coefficients at a structural-ferromagnetic transition

    No full text
    Accurate measurements of the electrical resistivity, the thermoelectric power and the thermal conductivity of TbZn are reported at the ferromagnetic-structural transition. The temperature derivative of the coefficients is examined. The critical behaviours are understood in terms of conduction electron scattering on spin correlated fluctuations and the presence of structural and magnetic domains

    Critical behaviour of transport coefficients at a structural-ferromagnetic transition

    No full text
    On rapporte des mesures précises de la résistivité électrique, du pouvoir thermoélectrique, et de la conductivité thermique de TbZn. La dérivée des coefficients par rapport à la température est examinée. Le comportement critique est expliqué par la diffusion électronique sur les fluctuations de spin corrélées et par la présence de domaines magnétiques et structuraux.Accurate measurements of the electrical resistivity, the thermoelectric power and the thermal conductivity of TbZn are reported at the ferromagnetic-structural transition. The temperature derivative of the coefficients is examined. The critical behaviours are understood in terms of conduction electron scattering on spin correlated fluctuations and the presence of structural and magnetic domains

    Cloning and characterization of AOEB166, a novel mammalian antioxidant enzyme of the peroxiredoxin family.

    No full text
    Using two-dimensional electrophoresis, we have recently identified in human bronchoalveolar lavage fluid a novel protein, termed B166, with a molecular mass of 17 kDa. Here, we report the cloning of human and rat cDNAs encoding B166, which has been renamed AOEB166 for antioxidant enzyme B166. Indeed, the deduced amino acid sequence reveals that AOEB166 represents a new mammalian subfamily of AhpC/TSA peroxiredoxin antioxidant enzymes. Human AOEB166 shares 63% similarity with Escherichia coli AhpC22 alkyl hydroperoxide reductase and 66% similarity with a recently identified Saccharomyces cerevisiae alkyl hydroperoxide reductase/thioredoxin peroxidase. Moreover, recombinant AOEB166 expressed in E. coli exhibits a peroxidase activity, and an antioxidant activity comparable with that of catalase was demonstrated with the glutamine synthetase protection assay against dithiothreitol/Fe3+/O(2) oxidation. The analysis of AOEB166 mRNA distribution in 30 different human tissues and in 10 cell lines shows that the gene is widely expressed in the body. Of interest, the analysis of N- and C-terminal domains of both human and rat AOEB166 reveals amino acid sequences presenting features of mitochondrial and peroxisomal targeting sequences. Furthermore, human AOEB166 expressed as a fusion protein with GFP in HepG2 cell line is sorted to these organelles. Finally, acute inflammation induced in rat lung by lipopolysaccharide is associated with an increase of AOEB166 mRNA levels in lung, suggesting a protective role for AOEB166 in oxidative and inflammatory processes
    corecore