1,322 research outputs found
One-loop Beta Functions for the Orientable Non-commutative Gross-Neveu Model
We compute at the one-loop order the beta-functions for a renormalisable
non-commutative analog of the Gross Neveu model defined on the Moyal plane. The
calculation is performed within the so called x-space formalism. We find that
this non-commutative field theory exhibits asymptotic freedom for any number of
colors. The beta-function for the non-commutative counterpart of the Thirring
model is found to be non vanishing.Comment: 16 pages, 9 figure
Rationale for UV-filtered clover fermions
We study the contributions Sigma_0 and Sigma_1, proportional to a^0 and a^1,
to the fermion self-energy in Wilson's formulation of lattice QCD with
UV-filtering in the fermion action. We derive results for m_{crit} and the
renormalization factors Z_S, Z_P, Z_V, Z_A to 1-loop order in perturbation
theory for several filtering recipes (APE, HYP, EXP, HEX), both with and
without a clover term. The perturbative series is much better behaved with
filtering, in particular tadpole resummation proves irrelevant. Our
non-perturbative data for m_{crit} and Z_A/(Z_m*Z_P) show that the combination
of filtering and clover improvement efficiently reduces the amount of chiral
symmetry breaking -- we find residual masses am_{res}=O(10^{-2}).Comment: 25 pages, 4 figures; v2: typo in eqn. (37) fixed [agrees with
published version
Correlation functions of eigenvalues of multi-matrix models, and the limit of a time dependent matrix
We consider the correlation functions of eigenvalues of a unidimensional
chain of large random hermitian matrices. An asymptotic expression of the
orthogonal polynomials allows to find new results for the correlations of
eigenvalues of different matrices of the chain. Eventually, we consider the
limit of the infinite chain of matrices, which can be interpreted as a time
dependent one-matrix model, and give the correlation functions of eigenvalues
at different times.Comment: Tex-Harvmac, 27 pages, submitted to Journ. Phys.
Developments in the negative-U modelling of the cuprate HTSC systems
The paper deals with the many stands that go into creating the unique and
complex nature of the HTSC cuprates above Tc as below. Like its predecessors it
treats charge, not spin or lattice, as prime mover, but thus taken in the
context of the chemical bonding relevant to these copper oxides. The crucial
shell filling, negative-U, double-loading fluctuations possible there require
accessing at high valent local environment as prevails within the mixed valent,
inhomogeneous two sub-system circumstance of the HTSC materials. Close
attention is paid to the recent results from Corson, Demsar, Li, Johnson,
Norman, Varma, Gyorffy and colleagues.Comment: 44 pages:200+ references. Submitted to J.Phys.:Condensed Matter, Sept
7 200
Spot urinary 5-hydroxyindoleacetic acid is not an ideal diagnostic test for acute appendicitis
Background and purpose of the studyThere is growing evidence to suggest the use of urinary 5-hydroxyindoleacetic acid (5-HIAA) test to help with the diagnosis of appendicitis. The aim of our study was to establish whether urinary 5-HIAA could be used as an effective diagnostic test for acute appendicitis.Design and methodsA prospective double-blinded study was carried out from December 2014 to October 2015. Patients admitted to the emergency surgical ward of a teaching hospital with suspected appendicitis were included in the study. The diagnostic accuracy of the test was measured by receiver operating characteristic curve.ResultsNinety-seven patients were divided into 2 groups: acute appendicitis (n = 38) and other diagnosis (n = 59). The median value of urinary 5-HIAA was 24.19 μmol/L (range, 5.39-138.27) for acute appendicitis vs 18.87 μmol/L (range, 2.27-120.59) for other diagnosis group (P = .038). The sensitivity and specificity of urinary 5-HIAA at a cutoff value of 19 μmol/L were 71% and 50%, respectively. Receiver operating characteristic analysis showed that the area under curve was 0.64 (confidence interval [CI], 0.513-0.737) for urinary 5-HIAA, which was lower than white blood cell count (0.69; CI, 0.574-0.797), neutrophil count (0.68; CI, 0.565-0.792), and C-reactive protein (0.76; CI, 0.657-0.857). There was no significant difference in the median values of 5-HIAA between different grades of severity of appendicitis (P = .704).ConclusionUrinary 5-HIAA is not an ideal test for the diagnosis of acute appendicitis
Mediation in the Law Curriculum
Cited by Lord Neuberger in ‘Educating Future Mediators’ at the 4th Civil Mediation Council National Conference, May 201
Towards a Tetravalent Chemistry of Colloids
We propose coating spherical particles or droplets with anisotropic
nano-sized objects to allow micron-scale colloids to link or functionalize with
a four-fold valence, similar to the sp3 hybridized chemical bonds associated
with, e.g., carbon, silicon and germanium. Candidates for such coatings include
triblock copolymers, gemini lipids, metallic or semiconducting nanorods and
conventional liquid crystal compounds. We estimate the size of the relevant
nematic Frank constants, discuss how to obtain other valences and analyze the
thermal distortions of ground state configurations of defects on the sphere.Comment: Replaced to improve figures. 4 figures Nano Letter
Abnormal ECG Findings in Athletes: Clinical Evaluation and Considerations.
PURPOSE OF REVIEW: Pre-participation cardiovascular evaluation with electrocardiography is normal practice for most sporting bodies. Awareness about sudden cardiac death in athletes and recognizing how screening can help identify vulnerable athletes have empowered different sporting disciplines to invest in the wellbeing of their athletes. RECENT FINDINGS: Discerning physiological electrical alterations due to athletic training from those representing cardiac pathology may be challenging. The mode of investigation of affected athletes is dependent on the electrical anomaly and the disease(s) in question. This review will highlight specific pathological ECG patterns that warrant assessment and surveillance, together with an in-depth review of the recommended algorithm for evaluation
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