425 research outputs found

    Journal Staff

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    This book constitutes the refereed proceedings of the 18th Scandinavian Conference on Image Analysis, SCIA 2013, held in Espoo, Finland, in June 2013. The 67 revised full papers presented were carefully reviewed and selected from 132 submissions. The papers are organized in topical sections on feature extraction and segmentation, pattern recognition and machine learning, medical and biomedical image analysis, faces and gestures, object and scene recognition, matching, registration, and alignment, 3D vision, color and multispectral image analysis, motion analysis, systems and applications, human-centered computing, and video and multimedia analysis

    Non-Fermi-liquid behavior in the Kondo lattices induced by peculiarities of magnetic ordering and spin dynamics

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    A scaling consideration of the Kondo lattices is performed with account of singularities in the spin excitation spectral function. It is shown that a non-Fermi-liquid (NFL) behavior between two critical values of the bare sfs-f coupling constant occurs naturally for complicated magnetic structures with several magnon branches. This may explain the fact that a NFL behavior takes place often in the heavy-fermion systems with peculiar spin dynamics. Another kind of a NFL-like state (with different critical exponents) can occur for simple antiferromagnets with account of magnon damping, and for paramagnets, especially with two-dimensional character of spin fluctuations. The mechanisms proposed lead to some predictions about behavior of specific heat, resistivity, magnetic susceptibility, and anisotropy parameter, which can be verified experimentally.Comment: 16 pages, RevTeX, 4 Postscript figures. Extended versio

    Combination therapy with an ACE inhibitor and an angiotensin receptor blocker for diabetic nephropathy - a meta-analysis

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    WSTĘP. Inhibitory konwertazy angiotensyny (ACEI) i blokery receptora angiotensyny (ARB) zapobiegają progresji nefropatii cukrzycowej (DN). Wyniki badań sugerują, że połączenie układu renina-angiotensyna-aldosteron (RAAS) i czynników hamujących działa addytywnie w procesie leczenia DN. Ponieważ badania te obejmowały niewielkie grupy chorych, autorzy niniejszej pracy przeprowadzili metaanalizę prób dotyczących leczenia skojarzonego DN. METODY. Badania do metaanalizy wybrano na podstawie baz danych MEDLINE, EMBASE, CINAHL i Cochrane. Włączono wszystkie próby dotyczące skojarzonego leczenia za pomocą ACEI i ARB. Głównym punktem końcowym było dobowe wydalanie białka z moczem, a dodatkowe punkty końcowe obejmowały: wartości ciśnienia tętniczego, stężenia potasu we krwi i współczynnika przesączania kłębuszkowego (GFR). WYNIKI. W 10 włączonych do analizy badaniach 156 chorych otrzymało ACEI i ARB, a 159 jedynie ACEI. Większość badań trwało 8-12 tygodni. U osób leczonych ACEI i ARB uzyskano zmniejszenie proteinurii (p = 0,01), co wiązało się ze znaczną statystyczną heterogenicznością (p = 0,005). Terapia ACEI i ARB była związana ze zmniejszeniem GFR [3,87 ml/min (7,32-0,42); p = 0,03] i tendencją do wzrostu stężenia kreatyniny w surowicy (6,86 umol/l 95% CI -0,76-13,73; p = 0,09). Stężenie potasu zwiększyło się o 0,2 (0,08-0,32) mmol/l (p < 0,01) u chorych leczonych ACEI i ARB. Skurczowe i rozkurczowe ciśnienie krwi obniżyło się odpowiednio o 5,2 mm Hg (2,1-8,4) (p < 0,01) i 5,3 mm Hg (2,2-8,4) (p < 0,01). WNIOSKI. Wyniki metaanalizy sugerują, że łączne stosowanie ACEI + ARB w większym stopniu zmniejsza 24-godzinne wydalanie białka z moczem niż przyjmowanie jedynie ACEI. Korzystne efekty terapii skojarzonej są wynikiem niewielkiego wpływu leków na GFR, stężenie kreatyniny i potasu w surowicy oraz ciśnienie tętnicze. Rezultaty te należy interpretować ostrożnie, ponieważ większość analizowanych badań charakteryzowała się krótkim czasem obserwacji, a w kilku długoterminowych próbach (12 miesięcy) nie wykazano korzystnego wpływu leczenia.AIMS. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) prevent the progression of diabetic nephropathy (DN). Studies suggest that combination renin-angiotensin-aldosterone system (RAAS)-inhibiting therapy provides additive benefit in DN. However, these studies are small in size. We performed a meta-analysis of studies investigating combination therapy for DN. METHODS. Studies were identified through a search of MEDLINE, EMBASE, CINAHL and the Cochrane Database. All trials involving combined ACEI and ARB for slowing progression of DN were included. The primary end point was 24- Blood pressure, serum potassium and glomerular filtration rate (GFR) were secondary end points. RESULTS. In the 10 included trials, 156 patients received ACEI + ARB and 159 received ACEI only. Most studies were 8&#8211;12 weeks in duration. Proteinuria was reduced with ACEI + ARB (p = 0.01). This was associated with significant statistical heterogeneity (p = 0.005). ACEI + ARB was associated with a reduction in GFR [3.87 ml/min (7.32-0.42); p = 0.03] and a trend towards an increase in serum creatinine (6.86 umol/l 95% CI: -0.76-13.73; p = 0.09). Potassium was increased by 0.2 (0.08-0.32) mmol/l (p < 0.01) with ACEI + ARB. Systolic and diastolic blood pressure were reduced by 5.2 (2.1-8.4) mm Hg (p < 0.01) and 5.3 (2.2-8.4) mm Hg (p < 0.01), respectively. CONCLUSIONS. This meta-analysis suggests that ACEI + + ARB reduces 24-h proteinuria to a greater extent than ACEI alone. This benefit is associated with small effects on GFR, serum creatinine, potassium and blood pressure. These results should be interpreted cautiously as most of the included studies were of short duration and the few long-term studies (12 months) have not demonstrated benefi

    Multi-Channel Kondo Necklace

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    A multi--channel generalization of Doniach's Kondo necklace model is formulated, and its phase diagram studied in the mean--field approximation. Our intention is to introduce the possible simplest model which displays some of the features expected from the overscreened Kondo lattice. The NN conduction electron channels are represented by NN sets of pseudospins \vt_{j}, j=1,...,Nj=1, ... , N, which are all antiferromagnetically coupled to a periodic array of |\vs|=1/2 spins. Exploiting permutation symmetry in the channel index jj allows us to write down the self--consistency equation for general NN. For N>2N>2, we find that the critical temperature is rising with increasing Kondo interaction; we interpret this effect by pointing out that the Kondo coupling creates the composite pseudospin objects which undergo an ordering transition. The relevance of our findings to the underlying fermionic multi--channel problem is discussed.Comment: 29 pages (2 figures upon request from [email protected]), LATEX, submitted for publicatio

    Genetic Homogeneity of the Invasive Lionfish Across the Northwestern Atlantic and the Gulf of Mexico Based On Single Nucleotide Polymorphisms

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    Despite the devastating impact of the lionfish (Pterois volitans) invasion on NW Atlantic ecosystems, little genetic information about the invasion process is available. We applied Genotyping by Sequencing techniques to identify 1,220 single nucleotide polymorphic sites (SNPs) from 162 lionfish samples collected between 2013 and 2015 from two areas chronologically identified as the first and last invaded areas in US waters: the east coast of Florida and the Gulf of Mexico. We used population genomic analyses, including phylogenetic reconstruction, Bayesian clustering, genetic distances, Discriminant Analyses of Principal Components, and coalescence simulations for detection of outlier SNPs, to understand genetic trends relevant to the lionfish’s long-term persistence. We found no significant differences in genetic structure or diversity between the two areas (FST p-values \u3e 0.01, and t-test p-values \u3e 0.05). In fact, our genomic analyses showed genetic homogeneity, with enough gene flow between the east coast of Florida and Gulf of Mexico to erase previous signals of genetic divergence detected between these areas, secondary spreading, and bottlenecks in the Gulf of Mexico. These findings suggest rapid genetic changes over space and time during the invasion, resulting in one panmictic population with no signs of divergence between areas due to local adaptation

    Quantum phase transitions in the Bose-Fermi Kondo model

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    We study quantum phase transitions in the Bose-Fermi Kondo problem, where a local spin is coupled to independent bosonic and fermionic degrees of freedom. Applying a second order expansion in the anomalous dimension of the Bose field we analyze the various non-trivial fixed points of this model. We show that anisotropy in the couplings is relevant at the SU(2) invariant non Fermi liquid fixed points studied earlier and thus the quantum phase transition is usually governed by XY or Ising-type fixed points. We furthermore derive an exact result that relates the anomalous exponent of the Bose field to that of the susceptibility at any finite coupling fixed point. Implications on the dynamical mean field approach to locally quantum critical phase transitions are also discussed.Comment: 13 pages, 9 figures, some references added/correcte

    Histopathology, vitellogenin and chemical body burden in mosquitofish (Gambusia holbrooki) sampled from six river sites receiving a gradient of stressors

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    There are over 40,000 chemical compounds registered for use in Australia, and only a handful are monitored in the aquatic receiving environments. Their effects on fish species in Australia are largely unknown. Mosquitofish (Gambusia holbrooki) were sampled from six river sites in Southeast Queensland identified as at risk from a range of pollutants. The sites selected were downstream of a wastewater treatment plant discharge, a landfill, two agricultural areas, and two sites in undeveloped reaches within or downstream of protected lands (national parks). Vitellogenin analysis, histopathology of liver, kidney and gonads, morphology of the gonopodium, and chemical body burden were measured to characterize fish health. Concentrations of trace organic contaminants (TrOCs) in water were analyzed by in vitro bioassays and chemical analysis. Estrogenic, anti-estrogenic, anti-androgenic, progestagenic and anti-progestagenic activities and TrOCs were detected in multiple water samples. Several active pharmaceutical ingredients (APIs), industrial compounds, pesticides and other endocrine active compounds were detected in fish carcasses at all sites, ranging from < 4–4700 ng/g wet weight, including the two undeveloped sites. While vitellogenin protein was slightly increased in fish from two of the six sites, the presence of micropollutants did not cause overt sexual endocrine disruption in mosquitofish (i.e., no abnormal gonads or gonopodia). A correlation between lipid accumulation in the liver with total body burden warrants further investigation to determine if exposure to low concentrations of TrOCs can affect fish health and increase stress on organs such as the liver and kidneys via other mechanisms, including disruption of non-sexual endocrine axes involved in lipid regulation and metabolism

    On Traversable Lorentzian Wormholes in the Vacuum Low Energy Effective String Theory in Einstein and Jordan Frames

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    Three new classes (II-IV) of solutions of the vacuum low energy effective string theory in four dimensions are derived. Wormhole solutions are investigated in those solutions including the class I case both in the Einstein and in the Jordan (string) frame. It turns out that, of the eight classes of solutions investigated (four in the Einstein frame and four in the corresponding string frame), massive Lorentzian traversable wormholes exist in five classes. Nontrivial massless limit exists only in class I Einstein frame solution while none at all exists in the string frame. An investigation of test scalar charge motion in the class I solution in the two frames is carried out by using the Plebanski-Sawicki theorem. A curious consequence is that the motion around the extremal zero (Keplerian) mass configuration leads, as a result of scalar-scalar interaction, to a new hypothetical "mass" that confines test scalar charges in bound orbits, but does not interact with neutral test particles.Comment: 18 page

    Superconductivity in the SU(N) Anderson Lattice at U=\infty

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    We present a mean-field study of superconductivity in a generalized N-channel cubic Anderson lattice at U=\infty taking into account the effect of a nearest-neighbor attraction J. The condition U=\infty is implemented within the slave-boson formalism considering the slave bosons to be condensed. We consider the ff-level occupancy ranging from the mixed valence regime to the Kondo limit and study the dependence of the critical temperature on the various model parameters for each of three possible Cooper pairing symmetries (extended s, d-wave and p-wave pairing) and find interesting crossovers. It is found that the d- and p- wave order parameters have, in general, very similar critical temperatures. The extended s-wave pairing seems to be relatively more stable for electronic densities per channel close to one and for large values of the superconducting interaction J.Comment: Seven Figures; one appendix. Accepted for publication in Phys. Rev.

    Auxiliary particle theory of threshold singularities in photoemission and X-ray absorption spectra: Test of a conserving T-matrix approximation

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    We calculate the exponents of the threshold singularities in the photoemission spectrum of a deep core hole and its X-ray absorption spectrum in the framework of a systematic many-body theory of slave bosons and pseudofermions (for the empty and occupied core level). In this representation, photoemission and X-ray absorption can be understood on the same footing; no distinction between orthogonality catastrophe and excitonic effects is necessary. We apply the conserving slave particle T-matrix approximation (CTMA), recently developed to describe both Fermi and non-Fermi liquid behavior systems with strong local correlations, to the X-ray problem as a test case. The numerical results for both photoemission and X-ray absorption are found to be in agreement with the exact infrared powerlaw behavior in the weak as well as in the strong coupling regions. We point out a close relation of the CTMA with the parquet equation approach of Nozi{\`e}res et al.Comment: 10 pages, 9 figures, published versio
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