Interpretation of the in-plane infrared response of the high-Tc cuprate superconductors involving spin fluctuations revisited

The in-plane infrared response of the high-Tc cuprate superconductors was studied using the spin-fermion model, where charged quasiparticles of the copper-oxygen planes are coupled to spin fluctuations. First, we analyzed structures of the superconducting-state conductivity reflecting the coupling of the quasiparticles to the resonance mode observed by neutron scattering. The conductivity computed with the input spin susceptibility in the simple form of the mode exhibits two prominent features: an onset of the real part of the conductivity starting around the frequency of the mode omega_{0} and a maximum of a related function W(omega), roughly proportional to the second derivative of the scattering rate, centered approximately at omega=omega_{0}+Delta_{0}/hbar, where Delta_{0} is the maximum value of the superconducting gap. The two structures are well known from earlier studies. Their physical meaning, however, has not been sufficiently elucidated thus far. Our analysis involving quasiparticle spectral functions provides a clear interpretation. Second, we explored the role played by the spin-fluctuation continuum. Third, we investigated the temperature dependence of the conductivity, of the intraband spectral weight, and of the effective kinetic energy. The changes of the latter two quantities below Tc are determined by the formation of the gap, by a feedback effect of the spin fluctuations on the quasiparticles, and by a significant shift of the chemical potential.Comment: 20 pages, 18 figures, submitted to Physical Review

Forecasting temporal dynamics of cutaneous leishmaniasis in Northeast Brazil.

IntroductionCutaneous leishmaniasis (CL) is a vector-borne disease of increasing importance in northeastern Brazil. It is known that sandflies, which spread the causative parasites, have weather-dependent population dynamics. Routinely-gathered weather data may be useful for anticipating disease risk and planning interventions.Methodology/principal findingsWe fit time series models using meteorological covariates to predict CL cases in a rural region of Bahía, Brazil from 1994 to 2004. We used the models to forecast CL cases for the period 2005 to 2008. Models accounting for meteorological predictors reduced mean squared error in one, two, and three month-ahead forecasts by up to 16% relative to forecasts from a null model accounting only for temporal autocorrelation.SignificanceThese outcomes suggest CL risk in northeastern Brazil might be partially dependent on weather. Responses to forecasted CL epidemics may include bolstering clinical capacity and disease surveillance in at-risk areas. Ecological mechanisms by which weather influences CL risk merit future research attention as public health intervention targets

Endocarditis with aortic root pseudoaneurysm rupture

We report a case of aortic valve endocarditis complicated by aortic root pseudoaneurysm and rupture. (Cardiol J 2007; 14: 202-204

Geographic Clustering of Leishmaniasis in Northeastern Brazil1

Different forms of this disease are spreading rapidly in distinct geographic clusters in this region

Geographic Association of Rickettsia felis-Infected Opossums with Human Murine Typhus, Texas

Application of molecular diagnostic technology in the past 10 years has resulted in the discovery of several new species of pathogenic rickettsiae, including Rickettsia felis. As more sequence information for rickettsial genes has become available, the data have been used to reclassify rickettsial species and to develop new diagnostic tools for analysis of mixed rickettsial pathogens. R. felis has been associated with opossums and their fleas in Texas and California. Because R. felis can cause human illness, we investigated the distribution dynamics in the murine typhus–endemic areas of these two states. The geographic distribution of R. felis-infected opossum populations in two well-established endemic foci overlaps with that of the reported human cases of murine typhus. Descriptive epidemiologic analysis of 1998 human cases in Corpus Christi, Texas, identified disease patterns consistent with studies done in the 1980s. A close geographic association of seropositive opossums (22% R. felis; 8% R. typhi) with human murine typhus cases was also observed

Miltefosine in the Treatment of Cutaneous Leishmaniasis Caused by Leishmania braziliensis in Brazil: A Randomized and Controlled Trial

Cutaneous leishmaniasis (CL) is characterized by skin ulcerations and occurs in rural poor areas of developing countries. It is treated with daily injections of antimony for 20 days, which is associated with irregular use and increasingly lower cure rates. Miltefosine is an oral medication with activity against the agent of CL (Leishmania). We have studied the efficacy and safety of miltefosine compared with antimony in patients with CL caused by Leishmania braziliensis in Bahia, Brazil. A total of 90 patients participated; 60 received miltefosine and 30 were treated with antimony. Six months after treatment, 75% of patients treated with miltefosine were cured, compared with 53% of the patients in the antimony group, a difference considered significant (p = 0.04). We also found that miltefosine was more effective than antimony in adults than in children. The incidence of side effects was similar with both drugs (76.7% vs. 78.3%), but all patients were able to finish the treatments. Our study shows that miltefosine is more effective than antimony for the treatment of CL in Bahia, Brazil and can contribute to the control of this disease due to its activity and easier administration

Whole genome single nucleotide polymorphism based phylogeny of Francisella tularensis and its application to the development of a strain typing assay

<p>Abstract</p> <p>Background</p> <p>A low genetic diversity in <it>Francisella tularensis </it>has been documented. Current DNA based genotyping methods for typing <it>F. tularensis </it>offer a limited and varying degree of subspecies, clade and strain level discrimination power. Whole genome sequencing is the most accurate and reliable method to identify, type and determine phylogenetic relationships among strains of a species. However, lower cost typing schemes are necessary in order to enable typing of hundreds or even thousands of isolates.</p> <p>Results</p> <p>We have generated a high-resolution phylogenetic tree from 40 <it>Francisella </it>isolates, including 13 <it>F. tularensis </it>subspecies <it>holarctica </it>(type B) strains, 26 <it>F. tularensis </it>subsp. <it>tularensis </it>(type A) strains and a single <it>F. novicida </it>strain. The tree was generated from global multi-strain single nucleotide polymorphism (SNP) data collected using a set of six Affymetrix GeneChip^®resequencing arrays with the non-repetitive portion of LVS (type B) as the reference sequence complemented with unique sequences of SCHU S4 (type A). Global SNP based phylogenetic clustering was able to resolve all non-related strains. The phylogenetic tree was used to guide the selection of informative SNPs specific to major nodes in the tree for development of a genotyping assay for identification of <it>F. tularensis </it>subspecies and clades. We designed and validated an assay that uses these SNPs to accurately genotype 39 additional <it>F. tularensis </it>strains as type A (A1, A2, A1a or A1b) or type B (B1 or B2).</p> <p>Conclusion</p> <p>Whole-genome SNP based clustering was shown to accurately identify SNPs for differentiation of <it>F. tularensis </it>subspecies and clades, emphasizing the potential power and utility of this methodology for selecting SNPs for typing of <it>F. tularensis </it>to the strain level. Additionally, whole genome sequence based SNP information gained from a representative population of strains may be used to perform evolutionary or phylogenetic comparisons of strains, or selection of unique strains for whole-genome sequencing projects.</p

Infekcyjne zapalenie wsierdzia z pęknięciem tętniaka rzekomego opuszki aorty

W niniejszej pracy opisano przypadek infekcyjnego zapalenie wsierdzia zastawki aortalnej, powikłanego powstaniem tętniaka rzekomego opuszki aorty z jego następowym pęknięciem. (Folia Cardiologica Excerpta 2007; 2: 207-210

Microbiota-produced indole metabolites disrupt mitochondrial function and inhibit Cryptosporidium parvum growth

Cryptosporidiosis is a leading cause of life-threatening diarrhea in young children in resource-poor settings. To explore microbial influences on susceptibility, we screened 85 microbiota-associated metabolites for their effects on Cryptosporidium parvum growth in vitro. We identify eight inhibitory metabolites in three main classes: secondary bile salts/acids, a vitamin

Transferrable protection by gut microbes against STING-associated lung disease

STING modulates immunity by responding to bacterial and endogenous cyclic dinucleotides (CDNs). Humans and mice with STING gain-of-function mutations develop a syndrome known as STING-associated vasculopathy with onset in infancy (SAVI), which is characterized by inflammatory or fibrosing lung disease. We hypothesized that hyperresponsiveness of gain-of-function STING to bacterial CDNs might explain autoinflammatory lung disease in SAVI mice. We report that depletion of gut microbes with oral antibiotics (vancomycin, neomycin, and ampicillin [VNA]) nearly eliminates lung disease in SAVI mice, implying that gut microbes might promote STING-associated autoinflammation. However, we show that germ-free SAVI mice still develop severe autoinflammatory disease and that transferring gut microbiota from antibiotics-treated mice to germ-free animals eliminates lung inflammation. Depletion of anaerobes with metronidazole abolishes the protective effect of the VNA antibiotics cocktail, and recolonization with the metronidazole-sensitive anaerobe Bacteroides thetaiotaomicron prevents disease, confirming a protective role of a metronidazole-sensitive microbe in a model of SAVI