44 research outputs found
Model of macroeconomic evolution in stable regionally dependent economic fields
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 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
The magneto-thermoelectric power (TEP) of perovskite type
manganise oxide is found to exhibit a sharp peak
at some temperature . By approximating the true shape of the
measured magneto-TEP in the vicinity of by a linear triangle of the
form , we observe that . 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 and the "metal-insulator" (M-I) transition at
. The latter is characterized by the divergence of the field-dependent
charge carrier localization length at some characteristic field
. Calculating the average and fluctuation contributions to the total
magnetization and the transport entropy related magneto-TEP
within the GL theory, we obtain a simple relationship between and the
above two critical temperatures ( and ). The observed slope
ratio is found to be governed by the competition between
the electron-spin exchange and the induced magnetic energy . The
comparison of our data with the model predictions produce ,
, , , and 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
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
<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
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)
Active breathing control combined with high dose 3D conformal radiotherapy for non small cell lung cancer patients with severe respiratory insufficiency: experience of the Centre Léon Bérard
International audienc
Mitochondrial targeting of peroxiredoxin 5 is preserved from annelids to mammals but is absent in pig Sus scrofa domesticus.
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
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
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.
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