Slave-Boson Three-Band Model with O-O Hopping for High-Tc Superconductors

Slave boson mean-field approximation is carried out analytically for weakly doped CuO_2 conduction planes, characterized by Cu-O charge transfer energy \Delta_{pd}, Cu-O hopping t_0, O-O hopping t' and repulsion U_d between holes on Cu site taken as infinite. At zero doping \delta, finite negative t',|t'|<t_0/2, expands the range of stability of the covalent, conducting state on the expense of the insulating state which, however, remains stable at larger \Delta_{pd}. For sufficiently large \Delta_{pd} the renormalized charge transfer energy saturates at 4|t'| instead of decreasing to zero, as at t'=0 case. In contrast to t', finite \delta suppresses the insulating state nearly symmetrically with respect to the sign of \delta. The regime with charge transfer energy renormalized close to 4|t'| fits remarkably well the ARPES spectra of Bi2212 and LSCO, and, in the latter case, explains the observed strong doping dependence of the Cu-O hopping.Comment: 4 pages, 2 figure

Microbial key players involved in P turnover differ in artificial soil mixtures depending on clay mineral composition.

Nutrient turnover in soils is strongly driven by soil properties, including clay mineral composition. One main nutrient is phosphorus (P), which is known to be easily immobilized in soil. Therefore, the specific surface characteristics of clay minerals might substantially influence P availability in soil and thus the microbial strategies for accessing P pools. We used a metagenomic approach to analyze the microbial potential to access P after 842 days of incubation in artificial soils with a clay mineral composition of either non-expandable illite (IL) or expandable montmorillonite (MT), which differ in their surface characteristics like soil surface area and surface charge. Our data indicate that microorganisms of the two soils developed different strategies to overcome P depletion, resulting in similar total P concentrations. Genes predicted to encode inorganic pyrophosphatase (ppa), exopolyphosphatase (ppx), and the pstSCAB transport system were higher in MT, suggesting effective P uptake and the use of internal poly-P stores. Genes predicted to encode enzymes involved in organic P turnover like alkaline phosphatases (phoA, phoD) and glycerophosphoryl diester phosphodiesterase were detected in both soils in comparable numbers. In addition, P-o concentrations did not differ significantly. Most identified genes were assigned to microbial lineages generally abundant in agricultural fields, but some were assigned to lineages known to include oligotrophic specialists, such as Bacillaceae and Microchaetaceae

Bacterial diversity of naturally fermented game meat sausages: Sources of new starter cultures.

Bacterial communities associated with the ripening process in artisanal wild boar and deer meat sausages were investigated by molecular barcoding using the 16S rRNA gene as a marker. A core microbiota shared by 83.54% of the samples indicated remarkable level of Lactobacillus sake/and Lactobacillus curvatus, accounting for 20.55% in initial and 70.48% in final products as well as spoilage-associated bacteria including Stenotrophomonas, Bacillus, Pseudomonas, Carnobacterium and Brochothrbc, with an average abundance 44.15% at the beginning and 13.98% at the end of the production. Of selected LAB isolates (n = 555), 43.83% were not suitable for food application due to the antibiotic resistance or the presence of the tric gene. Most of the strains designated as safe were able to grow at 25 degrees C even in the presence of 3.0 and 6.0% of NaCl or pH 4.5, but exposure to the same stressors resulted in growth reduction at 12 degrees C. Acidification and antimicrobial activity were found in 65.62% and 37.50% of strains, respectively. Most of the strains showed lipolytic and proteolytic activity, but only 9.37% were able to degrade sarcoplasmic proteins. These results give important information for the development of new starter formulation for the production of high quality game meat sausages

Specific Variants in the MLH1 Gene Region May Drive DNA Methylation, Loss of Protein Expression, and MSI-H Colorectal Cancer

Background: We previously identified an association between a mismatch repair gene, MLH1, promoter SNP (rs1800734) and microsatellite unstable (MSI-H) colorectal cancers (CRCs) in two samples. The current study expanded on this finding as we explored the genetic basis of DNA methylation in this region of chromosome 3. We hypothesized that specific polymorphisms in the MLH1 gene region predispose it to DNA methylation, resulting in the loss of MLH1 gene expression, mismatch-repair function, and consequently to genome-wide microsatellite instability. Methodology/Principal Findings: We first tested our hypothesis in one sample from Ontario (901 cases, 1,097 controls) and replicated major findings in two additional samples from Newfoundland and Labrador (479 cases, 336 controls) and from Seattle (591 cases, 629 controls). Logistic regression was used to test for association between SNPs in the region of MLH1 and CRC, MSI-H CRC, MLH1 gene expression in CRC, and DNA methylation in CRC. The association between rs1800734 and MSI-H CRCs, previously reported in Ontario and Newfoundland, was replicated in the Seattle sample. Two additional SNPs, in strong linkage disequilibrium with rs1800734, showed strong associations with MLH1 promoter methylation, loss of MLH1 protein, and MSI-H CRC in all three samples. The logistic regression model of MSI-H CRC that included MLH1-promotermethylation status and MLH1 immunohisotchemistry status fit most parsimoniously in all three samples combined. When rs1800734 was added to this model, its effect was not statistically significant (P-value = 0.72 vs. 2.361024 when the SNP was examined alone). Conclusions/Significance: The observed association of rs1800734 with MSI-H CRC occurs through its effect on the MLH1 promoter methylation, MLH1 IHC deficiency, or both

A rationalist perspective on the autonomy of international sport governing bodies : towards a pragmatic autonomy in the steering of sports

International sport governing bodies (ISGBs) are built on the foundations of freedom of association and traditionally enjoy a large degree of autonomy in their decision-making. Their autonomy is increasingly confined, however, and their hierarchical self-governance is giving way to a more networked governance, in which different stakeholders exert power in different ways and in different contexts in a complex web of interrelationships. Taking a rationalist perspective on the autonomy of ISGBs, this article demonstrates that ISGBs are deploying strategies to safeguard their waning governing monopoly over international sport. Opting for an inductive approach, the authors present four possible conceptualizations of autonomy as applied to ISGBs, namely political autonomy, legal autonomy, financial autonomy and pyramidal autonomy. For each dimension, they describe the different strategies ISGBs wield in order to safeguard different dimensions of their autonomy. This article uses governance theories to hypothesize that the autonomy of ISGBs can be understood as 'pragmatic autonomy' since ISGBs only cede certain aspects of their autonomy under particular circumstances and when being subject to specific threats. Acting in a rationalist manner, they are able to keep control over governance developments in sport by using indirect and more subtle forms of governance