Odd-parity perturbations of self-similar Vaidya spacetime

We carry out an analytic study of odd-parity perturbations of the self-similar Vaidya space-times that admit a naked singularity. It is found that an initially finite perturbation remains finite at the Cauchy horizon. This holds not only for the gauge invariant metric and matter perturbation, but also for all the gauge invariant perturbed Weyl curvature scalars, including the gravitational radiation scalars. In each case, `finiteness' refers to Sobolev norms of scalar quantities on naturally occurring spacelike hypersurfaces, as well as pointwise values of these quantities.Comment: 28 page

Chrysotile biopersistence in the lungs of persons in the general population and exposed workers.

Lung burden analysis was performed on 126 autopsy cases of persons who died in New York City from 1966 through 1968. Of the 126 cases, 107 were probably non-occupationally exposed, judging by occupational history and asbestos body content of lung. Fifty-three of the 107 cases contained short chrysotile fibers/fibrils, < 5 microns in length, present in 3-fold greater amounts than were found in laboratory background controls. The fiber concentrations ranged from 1.8 to 15.7 x 10(6) f/gm/dry lung tissue, and the proportion of fibers > or = 5 microns in length was only 0.34% of the total chrysotile population found. Other inorganic particles present included fragments of amphiboles. In contrast to these data, the lung parenchyma of persons occupationally exposed to asbestos commonly showed the presence of other fiber types, especially amosite and crocidolite, at very much higher concentrations and greater fiber length. Any chrysotile present would usually be in fiber bundle form, with both fibers and fibrils > 5 microns in length. Comparison of the lung fiber content of occupationally exposed persons with that of the general population showed marked qualitative and quantitative differences. Fibers are durable, and are retained in a range of concentrations. Their length and dose, among other factors, which control their biological potential are different in the two populations; the risk factors for chrysotile-induced disease are not the same

A process-based approach to health-related quality of life as a “way of living”

Introduction There is an historical initiative to establish common theoretical ground to support a framework for assessing health-related quality of life (HRQL). Our aim was to add to this effort with an analysis of theoretical/philosophical themes embedded in HRQL questionnaires and patient reports. Methods and Results We reviewed recent developments in HRQL assessment. This included analyzing a representative sample of psychometric measures of HRQL to schematically summarize core theoretical/philosophical themes that are embedded in questionnaire items. This analysis indicated a state-based framework for HRQL that was characterized by themes of hedonic and eudaimonic well-being, and desire-satisfaction. In contrast, a review of patient reports of HRQL indicated a process-based framework where goal-directed activities aimed to secure aspirational life goals while striving to accept the reality of declining health. Given this difference in HRQL themes we used a meta-philosophical approach, based on Hadot’s idea of philosophy as a way of living, to identify a process-based theoretical framework for HRQL assessment that addressed patient-reported themes. The Stoic modification of eudaimonic well-being was examined where HRQL and well-being are viewed as a process (vs. state) aimed at transforming the experience of loss or grief in response to adversity through goal-directed activities/exercises (euroia biou, good flow in life). We then introduced a complementary research agenda for HRQL assessment that incorporates self-reported, goal-directed activities that are initiated or maintained to promote HRQL. Conclusion A process-based approach to HRQL assessment may increase the spectrum of clinically relevant features that currently comprise operational measures of this patient-reported appraisal

A note on behaviour at an isotropic singularity

The behaviour of Jacobi fields along a time-like geodesic running into an isotropic singularity is studied. It is shown that the Jacobi fields are crushed to zero length at a rate which is the same in every direction orthogonal to the geodesic. We show by means of a counter-example that this crushing effect depends crucially on a technicality of the definition of isotropic singularities, and not just on the uniform degeneracy of the metric at the singularity.Comment: 13 pp. plain latex. To appear in Classical and Quantum Gravit

Primary Xanthoma of the Mandible: Report of a Rare Case

Xanthoma is a lesion most commonly seen in soft tissues such as the skin, subcutis, or tendon sheaths. Xanthoma formation is often associated with primary or secondary hyperlipidemia. Primary bone xanthomas are extremely rare benign bone lesions not associated with hyperlipidemia, histopathologically characterized by histiocytes, abundant lipid containing macrophages (foam cells), and multinucleated giant cells. Cholesterol clefts can be found in the medullary bone. Less than ten cases of xanthoma in the mandible have been reported. We present a rare primary intrabony xanthoma in a normolipidemic patient