Are Topological Charge Fluctuations in QCD Instanton Dominated?

We consider a recent proposal by Horv\'ath {\em et al.} to address the question whether topological charge fluctuations in QCD are instanton dominated via the response of fermions using lattice fermions with exact chiral symmetry, the overlap fermions. Considering several volumes and lattice spacings we find strong evidence for chirality of a finite density of low-lying eigenvectors of the overlap-Dirac operator in the regions where these modes are peaked. This result suggests instanton dominance of topological charge fluctuations in quenched QCD.Comment: LaTeX, 15 pages, 8 postscript figures, minor improvements, version to appear in PR

Development and validation of the Xhosa translations of the Beck Inventories: 2. Item analysis, internal consistency and factor analysis

The Beck Depression Inventory-II (BDI-II), the Beck Anxiety Inventory (BAI), and the Beck Hopelessness Scale (BHS) were translated Into Xhosa, a language widely spoken in South Africa to yield translated scales referred to as the XBDI-I (Xhosa BDI-II), the XBAI (Xhosa BAI) and the XBHS (Xhosa BHS). These scales were administered to a sample of 122 Xhosa respondents which Included students and patients. The psychometric properties of the translated scales were comparable to those of the original English versions. Measures of Internal consistency were as high as those for the validation studies in the USA and good Item-scale correlations were obtained. This suggests that the translation yielded clinically useful scales which tap symptoms that are largely culturally universal

Development and validation of the Xhosa translations of the Beck Inventories: 3. Concurrent and convergent validity

This article provides data on the validity of the Xhosa versions of the Beck Depression Inventory-II (XBDHI), the Beck Hopelessness Scale (XBHS) and the Beck Anxiety Inventory (XBAQ based on a sample of 122 Xhosa respondents which Included students and patients. For patients, clinicians completed rating scales of Depression and Anxiety symptoms. In tests of concurrent validity, depressed patients had significantly higher scores on the XBDI-II and XBHS than students or patients who were not depressed. Similarly anxious patients had higher scores on the XBAI than students and patients who were not anxious. Correlations with clinicians' ratings were: 91 for XBDI-II scores and depression ratings, and 88 for XBAI scores and anxiety ratings. Correlations between the three translated scales were similar to those for the original scales. These analyses provide evidence that the translated scales have levels of concurrent and convergent validity comparable to the originals

Development and validation of the Xhosa translations of the Beck Inventories: 1. Challenges of the translation process

This article describes the translation of the Beck Depression Inventory-II, the Beck Hopeless Scale, and the Beck Anxiety Inventory, into Xhosa the language spoken in the Eastern Cape of South Africa. The processes of translation, back-translation and committee discussion failed to yield trustworthy translations because of practical difficulties in working with translators. Critical words and phrases were identified which gave rise to lack of agreement. For each, a range of options was generated and the advantages and disadvantages evaluated in terms of criteria such as conceptual and idiomatic equivalence, and extensiveness of usage. Examples are given of the problems encountered and the way in which final decisions were made. A pilot clinical trial demonstrated the acceptability of the translated Instruments. Two further articles report the psychometric evaluation of the translated scales

Selecting children for head CT following head injury

OBJECTIVE: Indicators for head CT scan defined by the 2007 National Institute for Health and Care Excellence (NICE) guidelines were analysed to identify CT uptake, influential variables and yield. DESIGN: Cross-sectional study. SETTING: Hospital inpatient units: England, Wales, Northern Ireland and the Channel Islands. PATIENTS: Children (3 years were much more likely to have CT than those <3 years (OR 2.35 (95% CI 2.08 to 2.65)). CONCLUSION: Compliance with guidelines and diagnostic yield was variable across age groups, the type of hospital and region where children were admitted. With this pattern of clinical practice the risks of both missing intracranial injury and overuse of CT are considerable

Baryon operators and spectroscopy in lattice QCD

The construction of the operators and correlators required to determine the excited baryon spectrum is presented, with the aim of exploring the spatial and spin structure of the states while minimizing the number of propagator inversions. The method used to construct operators that transform irreducibly under the symmetries of the lattice is detailed, and the properties of example operators are studied using domain-wall fermion valence propagators computed on MILC asqtad dynamical lattices.Comment: 7 pages, 2 figures, to appear in Proceedings of Workshop on Lattice Hadron Physics 2003, Cairns, Australia, July 22 - July 30, 200