On the resistivity at low temperatures in electron-doped cuprate superconductors

We measured the magnetoresistance as a function of temperature down to 20mK and magnetic field for a set of underdoped PrCeCuO (x=0.12) thin films with controlled oxygen content. This allows us to access the edge of the superconducting dome on the underdoped side. The sheet resistance increases with increasing oxygen content whereas the superconducting transition temperature is steadily decreasing down to zero. Upon applying various magnetic fields to suppress superconductivity we found that the sheet resistance increases when the temperature is lowered. It saturates at very low temperatures. These results, along with the magnetoresistance, cannot be described in the context of zero temperature two dimensional superconductor-to-insulator transition nor as a simple Kondo effect due to scattering off spins in the copper-oxide planes. We conjecture that due to the proximity to an antiferromagnetic phase magnetic droplets are induced. This results in negative magnetoresistance and in an upturn in the resistivity.Comment: Accepted in Phys. Rev.

Notes on Contributions to the Science of Rare Earth Element Enrichment in Coal and Coal Combustion Byproducts

Coal and coal combustion byproducts can have significant concentrations of lanthanides (rare earth elements). Rare earths are vital in the production of modern electronics and optics, among other uses. Enrichment in coals may have been a function of a number of processes, with contributions from volcanic ash falls being among the most significant mechanisms. In this paper, we discuss some of the important coal-based deposits in China and the US and critique classification systems used to evaluate the relative value of the rare earth concentrations and the distribution of the elements within the coals and coal combustion byproducts

Development of Short-Form Versions of the Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R):A Proof-of-Principle Study

BACKGROUND: The Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R) is a 24-item questionnaire designed to assess risk of aberrant medication-related behaviors in chronic pain patients. The introduction of short forms of the SOAPP-R may save time and increase utilization by practitioners. OBJECTIVE: To develop and evaluate candidate SOAPP-R short forms. DESIGN: Retrospective study. SETTING: Pain centers. SUBJECTS: Four hundred and twenty-eight patients with chronic noncancer pain. METHODS: Subjects had previously been administered the full-length version of the SOAPP-R and been categorized as positive or negative for aberrant medication-related behaviors via the Aberrant Drug Behavior Index (ADBI). Short forms of the SOAPP-R were developed using lasso logistic regression. Sensitivity, specificity, and area under the curve (AUC) of all forms were calculated with respect to the ADBI using the complete data set, training-test analysis, and 10-fold cross-validation. The coefficient alpha of each form was also calculated. An external set of 12 pain practitioners reviewed the forms for content. RESULTS: In the complete data set analysis, a form of 12 items exhibited sensitivity, specificity, and AUC greater than or equal to those of the full-length SOAPP-R (which were 0.74, 0.67, and 0.76, respectively). The short form had a coefficient alpha of 0.76. In the training-test analysis and 10-fold cross-validation, it exhibited an AUC value within 0.01 of that of the full-length SOAPP-R. The majority of external practitioners reported a preference for this short form. CONCLUSIONS: The 12-item version of the SOAPP-R has potential as a short risk screener and should be tested prospectively

Sequential solvent extraction for the modes of occurrence of selenium in coals of different ranks from the Huaibei Coalfield, China

Forms of selenium in bituminous coal, anthracite, and cokeite (natural coke) from Huaibei Coalfield, Anhui, China, have been determined by sequential solvent extraction. The selenium content in bulk samples is 4.0, 2.4, and 2.0 μg/g in bituminous coal, anthracite, and cokeite, respectively. The six forms of selenium determined by six-step solvent extraction are water-leachable, ion-exchangeable, organic matter-associated, carbonate-associated, silicate-associated, and sulfide-associated. The predominant forms of selenium in bituminous coal are organic matter-associated (39.0%), sulfide-associated (21.1%), and silicate bound (31.8%); these three forms account for 92% of the total. The organic matter bound-selenium decrease dramatically from bituminous coal (39.0%) to anthracite (11.6%) and to cokeite (0%), indicating that organic matter bound selenium is converted to other forms during metamorphism of the coal, most likely sulfide-form. The sulfide-associated form increased remarkably from bituminous coal (21.1%) to anthracite (50.4%) and cokeite (54.5%), indicating the formation of selenium sulfide, possibly in pyrite during the transformation of bituminous coal to anthracite and cokeite. The silicate-associated selenium in bituminous coal (31.8%) is much higher than that in anthracite (16.4%) and cokeite (15.8%), indicating that silicate-associated selenium is partly converted to sulfide during metamorphism

γδ T cells affect IL-4 production and B-cell tolerance

γδ T cells can influence specific antibody responses. Here, we report that mice deficient in individual γδ T-cell subsets have altered levels of serum antibodies, including all major subclasses, sometimes regardless of the presence of αβ T cells. One strain with a partial γδ deficiency that increases IgE antibodies also displayed increases in IL-4–producing T cells (both residual γδ T cells and αβ T cells) and in systemic IL-4 levels. Its B cells expressed IL-4–regulated inhibitory receptors (CD5, CD22, and CD32) at diminished levels, whereas IL-4–inducible IL-4 receptor α and MHCII were increased. They also showed signs of activation and spontaneously formed germinal centers. These mice displayed IgE-dependent features found in hyper-IgE syndrome and developed antichromatin, antinuclear, and anticytoplasmic autoantibodies. In contrast, mice deficient in all γδ T cells had nearly unchanged Ig levels and did not develop autoantibodies. Removing IL-4 abrogated the increases in IgE, antichromatin antibodies, and autoantibodies in the partially γδ-deficient mice. Our data suggest that γδ T cells, controlled by their own cross-talk, affect IL-4 production, B-cell activation, and B-cell tolerance

Lenticular galaxies with UV-rings

By using the public UV imaging data obtained by the GALEX (Galaxy Ultraviolet Explorer) for nearby galaxies, we have compiled a list of lenticular galaxies possessing ultraviolet rings - starforming regions tightly confined to particular radial distances from galactic centers. We have studied large-scale structure of these galaxies in the optical bands by using the data of the SDSS (Sloan Digital Sky Survey): we have decomposed the galactic images into large-scale disks and bulges, have measured the ring optical colours from the residual images after subtracting model disks and bulges, and have compared the sizes of the rings in the optical light and in the UV-band. The probable origin of the outer starforming ring appearances in unbarred galaxies demonstrating otherwise the regular structure and homogeneously old stellar population beyond the rings is discussed.Comment: 9 pages plus one big colour figure in the Appendix; the slightly expanded version of the paper accepted to Astronomy Letter

Correction: Delayed Goblet Cell Hyperplasia, Acetylcholine Receptor Expression, and Worm Expulsion in SMC-Specific IL-4Rα–Deficient Mice

Interleukin 4 receptor alpha (IL-4Ralpha) is essential for effective clearance of gastrointestinal nematode infections. Smooth muscle cells are considered to play a role in the type 2 immune response-driven expulsion of gastrointestinal nematodes. Previous studies have shown in vitro that signal transducer and activator of transcription 6 signaling in response to parasitic nematode infection significantly increases smooth muscle cell contractility. Inhibition of the IL-4Ralpha pathway inhibits this response. How this response manifests itself in vivo is unknown. In this study, smooth muscle cell IL-4Ralpha-deficient mice (SM-MHC(Cre)IL-4Ralpha(-/lox)) were generated and characterized to uncover any role for IL-4/IL-13 in this non-immune cell type in response to Nippostrongylus brasiliensis infection. IL-4Ralpha was absent from alpha-actin-positive smooth muscle cells, while other cell types showed normal IL-4Ralpha expression, thus demonstrating efficient cell-type-specific deletion of the IL-4Ralpha gene. N. brasiliensis-infected SM-MHC(Cre)IL-4Ralpha(-/lox) mice showed delayed ability to resolve infection with significantly prolonged fecal egg recovery and delayed worm expulsion. The delayed expulsion was related to a delayed intestinal goblet cell hyperplasia, reduced T helper 2 cytokine production in the mesenteric lymph node, and reduced M3 muscarinic receptor expression during infection. Together, these results demonstrate that in vivo IL-4Ralpha-responsive smooth muscle cells are beneficial for N. brasiliensis expulsion by coordinating T helper 2 cytokine responses, goblet hyperplasia, and acetylcholine responsiveness, which drive smooth muscle cell contractions