574 research outputs found

    Breakdown of the Fermi-liquid regime in the 2D Hubbard model from a two-loop field-theoretical renormalization group approach

    Full text link
    We analyze the particle-hole symmetric two-dimensional Hubbard model on a square lattice starting from weak-to-moderate couplings by means of the field-theoretical renormalization group (RG) approach up to two-loop order. This method is essential in order to evaluate the effect of the momentum-resolved anomalous dimension η(p)\eta(\textbf{p}) which arises in the normal phase of this model on the corresponding low-energy single-particle excitations. As a result, we find important indications pointing to the existence of a non-Fermi liquid (NFL) regime at temperature T0T\to 0 displaying a truncated Fermi surface (FS) for a doping range exactly in between the well-known antiferromagnetic insulating and the dx2y2d_{x^2-y^2}-wave singlet superconducting phases. This NFL evolves as a function of doping into a correlated metal with a large FS before the dx2y2d_{x^2-y^2}-wave pairing susceptibility finally produces the dominant instability in the low-energy limit.Comment: 9 pages, 9 figures; published in Phys. Rev.

    Ambulatory care, insurance, and avoidable emergency department utilization in North Carolina

    Get PDF
    Objective: To examine whether and how avoidable emergency department (ED) utilization is associated with ambulatory or primary care (APC) utilization, insurance, and interaction effects. Design and sample: A cross-sectional analysis of electronic health records from 70,870 adults residing in Mecklenburg County, North Carolina, who visited an ED within a large integrated healthcare system in 2017. Methods: APC utilization was measured as total visits, categorized as: 0, 1, and > 1. Insurance was defined as the method of payment for the ED visit as: Medicaid, Medicare, private, or uninsured. Avoidable ED utilization was quantified as a score (aED), calculated as the sum of New York University Algorithm probabilities multiplied by 100. Quantile regression models were used to predict the 25th, 50th, 75th, 95th, and 99th percentiles of avoidable ED scores with APC visits and insurance as predictors (Model 1) and with an interaction term (Model 2). Results: Having >1 APC visit was negatively associated with aED at the lower percentiles and positively associated at higher percentiles. A higher aED was associated with having Medicaid insurance and a lower aED was associated with having private insurance, compared to being uninsured. In stratified models, having >1 APC visit was negatively associated with aED at the 25th percentile for the uninsured and privately insured, but positively associated with aED at higher percentiles among the uninsured, Medicaid-insured, and privately insured. Conclusions: The association between APC utilization and avoidable ED utilization varied based on segments of the distribution of ED score and differed significantly by insurance type

    The utility of Google Trends data to examine interest in cancer screening

    Get PDF
    OBJECTIVES: We examined the utility of January 2004 to April 2014 Google Trends data from information searches for cancer screenings and preparations as a complement to population screening data, which are traditionally estimated through costly population-level surveys. SETTING: State-level data across the USA. PARTICIPANTS: Persons who searched for terms related to cancer screening using Google, and persons who participated in the Behavioral Risk Factor Surveillance System (BRFSS). PRIMARY AND SECONDARY OUTCOME MEASURES: (1) State-level Google Trends data, providing relative search volume (RSV) data scaled to the highest search proportion per week (RSV100) for search terms over time since 2004 and across different geographical locations. (2) RSV of new screening tests, free/low-cost screening for breast and colorectal cancer, and new preparations for colonoscopy (Prepopik). (3) State-level breast, cervical, colorectal and prostate cancer screening rates. RESULTS: Correlations between Google Trends and BRFSS data ranged from 0.55 for ever having had a colonoscopy to 0.14 for having a Pap smear within the past 3 years. Free/low-cost mammography and colonoscopy showed higher RSV during their respective cancer awareness months. RSV for Miralax remained stable, while interest in Prepopik increased over time. RSV for lung cancer screening, virtual colonoscopy and three-dimensional mammography was low. CONCLUSIONS: Google Trends data provides enormous scientific possibilities, but are not a suitable substitute for, but may complement, traditional data collection and analysis about cancer screening and related interests

    The postcranial skeleton of monolophosaurus jiangi (dinosauria: Theropoda) from the Middle Jurassic of Xinjiang, China, and a review of Middle Jurassic Chinese theropods

    Get PDF
    The Middle Jurassic was a critical time in the evolution of theropod dinosaurs, highlighted by the origination and radiation of the large-bodied and morphologically diverse Tetanurae. Middle Jurassic tetanurans are rare but have been described from Europe, South America and China. In particular, China has yielded a number of potential basal tetanurans, but these have received little detailed treatment in the literature. Here we redescribe the postcranial skeleton of one of the most complete Chinese Middle Jurassic theropods, Monolophosaurus. Several features confirmthe tetanuran affinities of Monolophosaurus, but the possession of ‘primitive’ traits such as a double-faceted pubic peduncle of the ilium and a hood-like supracetabular crest suggest a basal position within Tetanurae. This conflicts with most published cladistic analyses that place Monolophosaurus in a more derived position within Allosauroidea.We review the Middle Jurassic record of Chinese theropods and compare Monolophosaurus to other Middle Jurassic theropods globally. These comparisons suggest that Monolophosaurus and Chuandongocoelurus formed an endemic theropod clade limited to the Middle Jurassic of Asia. Other Middle Jurassic Chinese theropods deserve further study

    A one-dimensional lattice model for a quantum mechanical free particle

    Get PDF
    Two types of particles, A and B with their corresponding antiparticles, are defined in a one dimensional cyclic lattice with an odd number of sites. In each step of time evolution, each particle acts as a source for the polarization field of the other type of particle with nonlocal action but with an effect decreasing with the distance: A -->...\bar{B} B \bar{B} B \bar{B} ... ; B --> A \bar{A} A \bar{A} A ... . It is shown that the combined distribution of these particles obeys the time evolution of a free particle as given by quantum mechanics.Comment: 8 pages. Revte

    AGATA, Technical Proposal for an Advanced Gamma Tracking Array for the European Gamma Spectroscopy Community

    Get PDF
    International audienceAn Advanced GAmma-ray Tracking Array, AGATA, is proposed for high-resolution γ-ray spectroscopy with exotic beams. AGATA will employ highly segmented Ge detectors as well as fully digital electronics and relies on newly developed pulse-shape analysis and tracking methods. The array is being designed in a way that it provides optimal properties for nuclear structure experiments in a wide range of beam velocities (from stopped to v/c ≈ 50%), almost independent of beam quality and background conditions. Selectivity and sensitivity of AGATA will be superior to any existing γ-array by several orders of magnitude. Hence, it will be for a long time a rich source for nuclear structure physics providing the means for new discoveries and opening challenging new perspectives. This document is the initial proposal sent to the European Commission to obtain the necessary funds for the project

    Using an Accessible Room Multisensory Stimulation Environment to Reduce Dementia Associated Behaviors

    Get PDF
    Objectives: To reveal whether an accessible open floorplan Multisensory Stimulation Environment (MSSE) room design has a positive impact as a nonpharmacologic intervention for episodes of Behavioral and Psychological Symptoms of Dementia (BPSD) in older adults living in a Memory Care Assisted Living (MCAL) facility as well as reducing the need for direct care supervision. Methods: Retrospective pre/post cohort design of 24 residents living in a Midwest MCAL facility in the United States with a diagnosis of dementia and over 65 years of age, analyzed by secondary medical chart review for 12 months to assess impact of an accessible open floorplan MSSE room design. The pre/post design analyzed secondary data over two periods of time; 6 months prior to the MSSE installation and 6 months following the MSSE installation. Results: Following the installation of an open floorplan MSSE, the number of observed BPSD episodes changed from 367 (17%) pre-test to 298 (10%) post-test over a 12-month time period. The Comparison of Proportions test determined that the difference in the proportion of BPSD episodes documented was statistically significant with clinical implications. Conclusions: The accessible open floorplan MSSE room design, located within a single-site MCAL facility, utilized as a nonpharmacological intervention for BPSD, was found in this explorative study to be effective and potentially clinically meaningful in improving behavioral episodes for older adults diagnosed with dementia in MCAL settings

    Performance of HPGe Detectors in High Magnetic Fields

    Full text link
    A new generation of high-resolution hypernuclear gamma$-spectroscopy experiments with high-purity germanium detectors (HPGe) are presently designed at the FINUDA spectrometer at DAPhiNE, the Frascati phi-factory, and at PANDA, the antiproton proton hadron spectrometer at the future FAIR facility. Both, the FINUDA and PANDA spectrometers are built around the target region covering a large solid angle. To maximise the detection efficiency the HPGe detectors have to be located near the target, and therefore they have to be operated in strong magnetic fields B ~ 1 T. The performance of HPGe detectors in such an environment has not been well investigated so far. In the present work VEGA and EUROBALL Cluster HPGe detectors were tested in the field provided by the ALADiN magnet at GSI. No significant degradation of the energy resolution was found, and a change in the rise time distribution of the pulses from preamplifiers was observed. A correlation between rise time and pulse height was observed and is used to correct the measured energy, recovering the energy resolution almost completely. Moreover, no problems in the electronics due to the magnetic field were observed.Comment: submitted to Nucl. Instrum. Meth. Phys. Res. A, LaTeX, 19 pages, 9 figure

    Equine Arteritis Virus Uses Equine CXCL16 as an Entry Receptor

    Get PDF
    Previous studies in our laboratory have identified equine CXCL16 (EqCXCL16) to be a candidate molecule and possible cell entry receptor for equine arteritis virus (EAV). In horses, the CXCL16 gene is located on equine chromosome 11 (ECA11) and encodes a glycosylated, type I transmembrane protein with 247 amino acids. Stable transfection of HEK-293T cells with plasmid DNA carrying EqCXCL16 (HEK-EqCXCL16 cells) increased the proportion of the cell population permissive to EAV infection from \u3c 3% to almost 100%. The increase in permissiveness was blocked either by transfection of HEK-EqCXCL16 cells with small interfering RNAs (siRNAs) directed against EqCXCL16 or by pretreatment with guinea pig polyclonal antibody against EqCXCL16 protein (Gp anti-EqCXCL16 pAb). Furthermore, using a virus overlay protein-binding assay (VOPBA) in combination with far-Western blotting, gradient-purified EAV particles were shown to bind directly to the EqCXCL16 protein in vitro. The binding of biotinylated virulent EAV strain Bucyrus at 4°C was significantly higher in HEK-EqCXCL16 cells than nontransfected HEK-293T cells. Finally, the results demonstrated that EAV preferentially infects subpopulations of horse CD14+ monocytes expressing EqCXCL16 and that infection of these cells is significantly reduced by pretreatment with Gp anti-EqCXCL16 pAb. The collective data from this study provide confirmatory evidence that the transmembrane form of EqCXCL16 likely plays a major role in EAV host cell entry processes, possibly acting as a primary receptor molecule for this virus

    Allelic Variation in \u3cem\u3eCXCL16\u3c/em\u3e Determines CD3\u3csup\u3e+\u3c/sup\u3e T Lymphocyte Susceptibility to Equine Arteritis Virus Infection and Establishment of Long-Term Carrier State in the Stallion

    Get PDF
    Equine arteritis virus (EAV) is the causative agent of equine viral arteritis (EVA), a respiratory, systemic, and reproductive disease of horses and other equid species. Following natural infection, 10–70% of the infected stallions can become persistently infected and continue to shed EAV in their semen for periods ranging from several months to life. Recently, we reported that some stallions possess a subpopulation(s) of CD3+ T lymphocytes that are susceptible to in vitro EAV infection and that this phenotypic trait is associated with long-term carrier status following exposure to the virus. In contrast, stallions not possessing the CD3+ T lymphocyte susceptible phenotype are at less risk of becoming long-term virus carriers. A genome wide association study (GWAS) using the Illumina Equine SNP50 chip revealed that the ability of EAV to infect CD3+ T lymphocytes and establish long-term carrier status in stallions correlated with a region within equine chromosome 11. Here we identified the gene and mutations responsible for these phenotypes. Specifically, the work implicated three allelic variants of the equine orthologue of CXCL16 (EqCXCL16) that differ by four non-synonymous nucleotide substitutions (XM_00154756; c.715 A → T, c.801 G → C, c.804 T → A/G, c.810 G → A) within exon 1. This resulted in four amino acid changes with EqCXCL16S (XP_001504806.1) having Phe, His, Ile and Lys as compared to EqCXL16R having Tyr, Asp, Phe, and Glu at 40, 49, 50, and 52, respectively. Two alleles (EqCXCL16Sa, EqCXCL16Sb) encoded identical protein products that correlated strongly with long-term EAV persistence in stallions (P \u3c 0.000001) and are required for in vitro CD3+ T lymphocyte susceptibility to EAV infection. The third (EqCXCL16R) was associated with in vitro CD3+ T lymphocyte resistance to EAV infection and a significantly lower probability for establishment of the long-term carrier state (viral persistence) in the male reproductive tract. EqCXCL16Sa and EqCXCL16Sb exert a dominant mode of inheritance. Most importantly, the protein isoform EqCXCL16S but not EqCXCL16R can function as an EAV cellular receptor. Although both molecules have equal chemoattractant potential, EqCXCL16S has significantly higher scavenger receptor and adhesion properties compared to EqCXCL16R
    corecore