The phase diagram of twisted mass lattice QCD

We use the effective chiral Lagrangian to analyze the phase diagram of two-flavor twisted mass lattice QCD as a function of the normal and twisted masses, generalizing previous work for the untwisted theory. We first determine the chiral Lagrangian including discretization effects up to next-to-leading order (NLO) in a combined expansion in which m_\pi^2/(4\pi f_\pi)^2 ~ a \Lambda (a being the lattice spacing, and \Lambda = \Lambda_{QCD}). We then focus on the region where m_\pi^2/(4\pi f_\pi)^2 ~ (a \Lambda)^2, in which case competition between leading and NLO terms can lead to phase transitions. As for untwisted Wilson fermions, we find two possible phase diagrams, depending on the sign of a coefficient in the chiral Lagrangian. For one sign, there is an Aoki phase for pure Wilson fermions, with flavor and parity broken, but this is washed out into a crossover if the twisted mass is non-vanishing. For the other sign, there is a first order transition for pure Wilson fermions, and we find that this transition extends into the twisted mass plane, ending with two symmetrical second order points at which the mass of the neutral pion vanishes. We provide graphs of the condensate and pion masses for both scenarios, and note a simple mathematical relation between them. These results may be of importance to numerical simulations.Comment: 13 pages, 5 figures, small clarifying comments added in introduction, minor typos fixed. Version to be published in Phys. Rev.

Differentiating Climatic And Successional Influences On Long-Term Development Of A Marsh

Comparison of long-term records of local wetland vegetation dynamics with regional, climate-forced terrestrial vegetation changes can be used to differentiate the rates and effects of autogenic successional processes and allogenic environmental change on wetland vegetation dynamics. We studied Holocene plant macrofossil and pollen sequences from Portage Marsh, a shallow, 18-ha marsh in northeastern Indiana. Between 10 000 and 5700 yr BP the basin was occupied by a shallow, open lake, while upland vegetation consisted of mesic forests of Pinus, Quercus, Ulmus, and Carya. At 5700 yr BP the open lake was replaced rapidly by a shallow marsh, while simultaneously Quercus savanna developed on the surrounding uplands. The marsh was characterized by periodic drawdowns, and the uplands by periodic fires. Species composition of the marsh underwent further changes between 3000 and 2000 yr BP. Upland pollen spectra at Portage Marsh and other sites in the region shifted towards more mesic vegetation during that period. The consistency and temporal correspondence between the changes in upland vegetation and marsh vegetation indicate that the major vegetational changes in the marsh during the Holocene resulted from hydrologic changes forced by regional climate change. Progressive shallowing of the basin by autogenic accumulation of organic sediment constrained vegetational responses to climate change but did not serve as the direct mechanism of change

Improving Medication Management after a Hospitalization with Pharmacist Home Visits and Electronic Personal Health Records: An Observational Study

Background: Substantial opportunity exists to improve medication management in the period following a hospital discharge. The objective of this study was to assess and improve medication management during care transitions through pharmacist home visits and the use of an electronic personal health record (ePHR) system. Methods: Recently discharged patients aged 50 years or older and having a chronic medical condition were offered the opportunity to meet with a pharmacist in the home setting to review medication instructions and receive a demonstration of an ePHR system. Patients agreeable to using the ePHR system were offered pharmacist support with setting up the ePHR system, having emphasis on documenting and reviewing medication regimens. Medication-related problems identified by the pharmacist during the visit were categorized according to ePHR use and by other characteristics. Results: Thirty recently discharged patients with chronic disease were visited by a pharmacist over a 6-month period. The percentage of medication-related problems identified by the pharmacist was greater among those patients who agreed to use the ePHR system, as compared with patients whose visit did not include use of the ePHR (75% versus 40%, respectively; P=0.06). Differing types of medication-related problems were identified, including therapy duplications, lack of use of clinically important therapies, and patient nonadherence. Conclusion: For some patients, the home setting can be a suitable venue for medication review and education after discharge from hospital. Assisting patients with setting up the ePHR system may enhance pharmacists’ ability to identify and resolve medication-related problems that may lead to rehospitalization

On Your MARK, Get SET(D2), Go! H3K36me3 Primes DNA Mismatch Repair

Trimethylation of histone H3 on Lys36 (H3K36me3) by SETD2 is linked to actively transcribed regions. Li et al. identify a novel role for H3K36me3 that facilitates DNA mismatch repair (MMR) in cells by targeting the MMR machinery to chromatin during the cell cycle, thereby explaining certain cases of MMR-defective cancers

Magnetic order in the SeffS_{\mathrm{eff}} = 1/2 triangular-lattice compound NdCd3_3P3_3

We present and characterize a new member of the $R$Cd$_3$P$_3$ ($R$= rare earth) family of materials, NdCd$_3$P$_3$, which possesses Nd$^{3+}$ cations arranged on well-separated triangular lattice layers. Magnetic susceptibility and heat capacity measurements demonstrate a likely $S_{\mathrm{eff}}$ = 1/2 ground state, and also reveal the formation of long-range antiferromagnetic order at $T_{N} = 0.34$ K. Via measurements of magnetization, heat capacity, and electrical resistivity, we characterize the electronic properties of NdCd$_3$P$_3$ and compare results to density functional theory calculations.Comment: Accepted for publication at Physical Review Material

Fundamental Behavior of Electric Field Enhancements in the Gaps Between Closely Spaced Nanostructures

We demonstrate that the electric field enhancement that occurs in a gap between two closely spaced nanostructures, such as metallic nanoparticles, is the result of a transverse electromagnetic waveguide mode. We derive an explicit semianalytic equation for the enhancement as a function of gap size, which we show has a universal qualitative behavior in that it applies irrespective of the material or geometry of the nanostructures and even in the presence of surface plasmons. Examples of perfect electrically conducting and Ag thin-wire antennas and a dimer of Ag spheres are presented and discussed.Comment: 9 pages and 4 figure

Harmonization - Towards A Standardized River Geometry Format

RiverML is a proposed language for conveying a description of river channel and floodplain geometry and flow characteristics through the internet in a standardized way, which is currently in the early stages of development. RiverML is a joint effort between the CUAHSI HydroShare development team, the World Meteorological Organization (WMO) / Open Geospatial Consortium (OGC) Hydrology Domain Working Group, and an international community of data providers, data users, and software developers. In order to create a standard that will serve the needs of the international hydrologic community, a harmonization effort of three forms of data is presented. First, relevant initiatives from public and private agencies around the world at the international, national, and regional levels are identified. Second, the input requirements and naming conventions for a collection of both design and research-oriented hydraulic software packages are compared. Third, the advantages and limitations of existing transfer formats are investigated. From these data, the goals of an international standard for river geometry are formulated as a set of use cases. The commonalities between existing workflows are used to establish the key information content which a standard format should convey. Finally, recommendations for the functional form and anticipated challenges to development are described

A General Tool for Engineering the NAD/NADP Cofactor Preference of Oxidoreductases

The ability to control enzymatic nicotinamide cofactor utilization is critical for engineering efficient metabolic pathways. However, the complex interactions that determine cofactor-binding preference render this engineering particularly challenging. Physics-based models have been insufficiently accurate and blind directed evolution methods too inefficient to be widely adopted. Building on a comprehensive survey of previous studies and our own prior engineering successes, we present a structure-guided, semirational strategy for reversing enzymatic nicotinamide cofactor specificity. This heuristic-based approach leverages the diversity and sensitivity of catalytically productive cofactor binding geometries to limit the problem to an experimentally tractable scale. We demonstrate the efficacy of this strategy by inverting the cofactor specificity of four structurally diverse NADP-dependent enzymes: glyoxylate reductase, cinnamyl alcohol dehydrogenase, xylose reductase, and iron-containing alcohol dehydrogenase. The analytical components of this approach have been fully automated and are available in the form of an easy-to-use web tool: Cofactor Specificity Reversal–Structural Analysis and Library Design (CSR-SALAD)

Genetic Diversity of PCR-Positive, Culture-Negative and Culture-Positive Mycobacterium ulcerans Isolated from Buruli Ulcer Patients in Ghana.

Culture of Mycobacterium ulcerans from Buruli ulcer patients has very low sensitivity. Thus confirmation of M. ulcerans infection is primarily based on PCR directed against IS2404. In this study we compare the genotypes obtained by variable number of tandem repeat analysis of DNA from IS2404-PCR positive cultures with that obtained from IS2404 positive, culture-negative tissue. A significantly greater genetic heterogeneity was found among culture-negative samples compared with that found in cultured strains but a single genotype is over-represented in both sample sets. This study provides evidence that both the focal location of bacteria in a lesion as well as differences in the ability to culture a particular genotype may underlie the low sensitivity of culture. Though preliminary, data from this work also suggests that mycobacteria previously associated with fish disease (M. pseudoshottsii) may be pathogenic for humans