Improved Epstein-Glaser Renormalization II. Lorentz invariant framework

The Epstein--Glaser type T-subtraction introduced by one of the authors in a previous paper is extended to the Lorentz invariant framework. The advantage of using our subtraction instead of Epstein and Glaser's standard W-subtraction method is especially important when working in Minkowski space, as then the counterterms necessary to keep Lorentz invariance are simplified. We show how T-renormalization of primitive diagrams in the Lorentz invariant framework directly relates to causal Riesz distributions. A covariant subtraction rule in momentum space is found, sharply improving upon the BPHZL method for massless theories.Comment: LaTeX, 15 pages, no figure. Version to be published in J. Math. Phys. (Section 7 on the Massive Case and some references have been withdrawn). To the Memory of Laurent Schwart

W-algebras from symplectomorphisms

It is shown how $W$-algebras emerge from very peculiar canonical transformations with respect to the canonical symplectic structure on a compact Riemann surface. The action of smooth diffeomorphisms of the cotangent bundle on suitable generating functions is written in the BRS framework while a $W$-symmetry is exhibited. Subsequently, the complex structure of the symmetry spaces is studied and the related BRS properties are discussed. The specific example of the so-called $W_3$-algebra is treated in relation to some other different approaches.Comment: LaTex, 25 pages, no figures, to appear in Journ. Math. Phy

The Polyakov action on the supertorus

A consistent method for obtaining a well-defined Polyakov action on the supertorus is presented. This method uses the covariantization of derivative operators and enables us to construct a Polyakov action which is globally defined.Comment: 15 pages LaTe

Spectral Line Removal in the LIGO Data Analysis System (LDAS)

High power in narrow frequency bands, spectral lines, are a feature of an interferometric gravitational wave detector's output. Some lines are coherent between interferometers, in particular, the 2 km and 4 km LIGO Hanford instruments. This is of concern to data analysis techniques, such as the stochastic background search, that use correlations between instruments to detect gravitational radiation. Several techniques of `line removal' have been proposed. Where a line is attributable to a measurable environmental disturbance, a simple linear model may be fitted to predict, and subsequently subtract away, that line. This technique has been implemented (as the command oelslr) in the LIGO Data Analysis System (LDAS). We demonstrate its application to LIGO S1 data.Comment: 11 pages, 5 figures, to be published in CQG GWDAW02 proceeding

Support immersion endoscopy in post-extraction alveolar bone chambers: a new window for microscopic bone imaging in Vivo

Using an endoscopic approach, small intraoral bone chambers, which are routinely obtained during tooth extraction and implantation, provide visual in vivo access to internal bone structures. The aim of the present paper is to present a new method to quantify bone microstructure and vascularisation in vivo. Ten extraction sockets and 6 implant sites in 14 patients (6 men / 8 women) were examined by support immersion endoscopy (SIE). After tooth extraction or implant site preparation, microscopic bone analysis (MBA) was performed using short distance SIE video sequences of representative bone areas for off-line analysis with ImageJ. Quantitative assessment of the microstructure and vascularisation of the bone in dental extraction and implant sites in vivo was performed using ImageJ. MBA revealed bone morphology details such as unmineralised and mineralised areas, vascular canals and the presence of bleeding through vascular canals. Morphometric examination revealed that there was more unmineralised bone and less vascular canal area in the implant sites than in the extraction sockets

Work-related stress mediate the relationship between safety climate and safety performance.

During the last few years the approach to prevention of injury has focused more on the human factor, highlighting the important role that work-related stress, safety climate and safety culture play in preventing work accidents (Fogarty, 2004). The main aim of the present study was to test Fogarty\u2019s (2004) proposition that the link between safety climate and errors is mediated by psychological health and that psychological stress has an important role as being among the immediate causes of accidents. For these reasons safety climate, safety performance and work-related stress were assessed in 98 metal and mechanical workers employed in two different companies in the north-east of Italy. The validated Integrated Organizational Safety Climate Questionnaire was used to assess three safety climate measures (Organizational, Supervisor and Co-worker). Each item on each measure has a 7-point scale that ranges from 1 = never to 7 = always. The Italian version of the HSE Management Standards Indicator Tool was used to asses work related stress. Each item has a 5-point scale that ranges from 1 = never to 5 = always. A Structural equation model showed that work related stress seemed to mediate the relationship between safety climate and safety performance. More data must to be collected to confirm the model. The results suggest the importance for management to monitor both safety climate and individual health variables to avoid accidents and errors

Induced Polyakov supergravity on Riemann surfaces of higher genus

An effective action is obtained for the $N=1$, $2D-$induced supergravity on a compact super Riemann surface (without boundary) $\hat\Sigma$ of genus $g>1$, as the general solution of the corresponding superconformal Ward identity. This is accomplished by defining a new super integration theory on $\hat\Sigma$ which includes a new formulation of the super Stokes theorem and residue calculus in the superfield formalism. Another crucial ingredient is the notion of polydromic fields. The resulting action is shown to be well-defined and free of singularities on \sig. As a by-product, we point out a morphism between the diffeomorphism symmetry and holomorphic properties.Comment: LPTB 93-10, Latex file 20 page