Ten Years» Experience of Aortic Aneurysm Associated with Systemic Lupus Erythematosus

AbstractBackground: aortic aneurysm is a rare but life-threatening cardiovascular complication in patients with systemic lupus erythematosus (SLE). The purpose of this study was to clarify the characteristic clinical features and the pathological mechanism of aneurysmal formation in these patients. Methods: among 429 patients operated on for abdominal aortic aneurysm (AAA) during the past 10 years, five cases with SLE were treated surgically. Their clinical data were reviewed, and the resected aneurysmal wall of the five patients was also examined histologically. Results: the mean age of the patients with SLE was 55 years, which was statistically younger than that of the other patients (mean 77 years, s.d. 7.9, p <0.05). They had received long-term corticosteroid therapy for the treatment of SLE for a mean of 23 years. Histologically, destruction of the medial elastic lamina was characteristic. Four patients had no complications in the postoperative follow-up period (mean 4 years), while the remaining patient died of rupture of a dissecting aneurysm two years after operation.Conclusion : prolonged steroid therapy may play a major role in accelerating atherosclerosis, which can result in aortic aneurysmal enlargement, possibly together with primary aortic wall involvement and/or vasculitic damage in patients with SLE

Self-Similar Collapse of Scalar Field in Higher Dimensions

This paper constructs continuously self-similar solution of a spherically symmetric gravitational collapse of a scalar field in n dimensions. The qualitative behavior of these solutions is explained, and closed-form answers are provided where possible. Equivalence of scalar field couplings is used to show a way to generalize minimally coupled scalar field solutions to the model with general coupling.Comment: RevTex 3.1, 15 pages, 3 figures; references adde

Surface gravity in dynamical spherically symmetric spacetimes

A definition of surface gravity at the apparent horizon of dynamical spherically symmetric spacetimes is proposed. It is based on a unique foliation by ingoing null hypersurfaces. The function parametrizing the hypersurfaces can be interpreted as the phase of a light wave uniformly emitted by some far-away static observer. The definition gives back the accepted value of surface gravity in the static case by virtue of its nonlocal character. Although the definition is motivated by the behavior of outgoing null rays, it turns out that there is a simple connection between the generalized surface gravity, the acceleration of any radially moving observer, and the observed frequency change of the infalling light signal. In particular, this gives a practical and simple method of how any geodesic observer can determine surface gravity by measuring only the redshift of the infalling light wave. The surface gravity can be expressed as an integral of matter field quantities along an ingoing null line, which shows that it is a continuous function along the apparent horizon. A formula for the area change of the apparent horizon is presented, and the possibility of thermodynamical interpretation is discussed. Finally, concrete expressions of surface gravity are given for a number of four-dimensional and two-dimensional dynamical black hole solutions.Comment: 35 pages, revtex, 3 figures included using eps

Self-Similar Collapse of Conformally Coupled Scalar Fields

A massless scalar field minimally coupled to the gravitational field in a simplified spherical symmetry is discussed. It is shown that, in this case, the solution found by Roberts, describing a scalar field collapse, is in fact the most general one. Taking that solution as departure point, a study of the gravitational collapse for the self-similar conformal case is presented.Comment: 9 pages, accepted for publication, Classical and Quantum Gravity. Available at http://dft.if.uerj.br/preprint/e-17.tex or at ftp://dft.if.uerj.br/preprint/e-17.tex . Figures can be obtained on request at [email protected]

Perturbations and Critical Behavior in the Self-Similar Gravitational Collapse of a Massless Scalar Field

This paper studies the perturbations of the continuously self-similar critical solution of the gravitational collapse of a massless scalar field (Roberts solution). The perturbation equations are derived and solved exactly. The perturbation spectrum is found to be not discrete, but occupying continuous region of the complex plane. The renormalization group calculation gives the value of the mass-scaling exponent equal to 1.Comment: 12 pages, RevTeX 3.1, 1 figur

Countable and Full Exchange Rings

We show that a suitable ring with a ``nice'' topology, in which convergent limits of units are units, is an \aleph_0-exchange ring. We generalize the argument to show that a semi-regular ring, R, with a ``nice'' topology, is a full exchange ring. Putting these results in the language of modules, we show that a cohopfian module with finite exchange has countable exchange. Also, all modules with Dedekind-finite, semi-regular endomorphism rings are full exchange modules.Comment: 15 page

Global tropical forest cover change assessment with medium spatial stellite imagery using a systematic sample grid - data, methods and first results.

At the Joint Research Centre (JRC) of the European Commission, a methodology has been developed to monitor the pan-tropical forest cover with remote sensing data for the years 1990-2000-2005 in Latin America, Southeast Asia and Africa on the basis of over 4000 sample units sample units with a dimension of 20 km by 20 km located at every full latitude and longitude degree confluence. From the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) instruments, images with low cloud impact from the epochs around the years 1990, 2000 and 2005 were selected and subsets covering the sample units were cut-out, pre-processed, segmented and classified in five different land cover classes in order to build global and regional statistics on tropical forest cover change. The data was validated in three steps, internal correction of wrongly classified objects, external (national or regional) expert validation and internal harmonization of the data. In this paper, the data collection and the workflow of the forest cover change assessment for the epochs 1990 and 2000 is presented. Parts of the results for the Brazilian Amazon have been validated by comparing with interpretations of corresponding samples carried out by the Instituto Nacional de Pesquisas Espaciais (INPE), showing a very high correlation. Further, the figure produced by INPE through the PRODES program on gross deforestation for the years 1990-2000 was compared to the figure calculated on basis of the JRC results for the respective area, where the JRC estimate that was ca. 10% higher than the INPE estimate

Continuous Self-Similarity Breaking in Critical Collapse

This paper studies near-critical evolution of the spherically symmetric scalar field configurations close to the continuously self-similar solution. Using analytic perturbative methods, it is shown that a generic growing perturbation departs from the critical Roberts solution in a universal way. We argue that in the course of its evolution, initial continuous self-similarity of the background is broken into discrete self-similarity with echoing period $\Delta = \sqrt{2}\pi = 4.44$, reproducing the symmetries of the critical Choptuik solution.Comment: RevTeX 3.1, 28 pages, 5 figures; discussion rewritten to clarify several issue

Energy transformation cost for the Japanese mid-century strategy

The costs of climate change mitigation policy are one of the main concerns in decarbonizing the economy. The macroeconomic and sectoral implications of policy interventions are typically estimated by economic models, which tend be higher than the additional energy system costs projected by energy system models. Here, we show the extent to which policy costs can be lower than those from conventional economic models by integrating an energy system and an economic model, applying Japan’s mid-century climate mitigation target. The GDP losses estimated with the integrated model were significantly lower than those in the conventional economic model by more than 50% in 2050. The representation of industry and service sector energy consumption is the main factor causing these differences. Our findings suggest that this type of integrated approach would contribute new insights by providing improved estimates of GDP losses, which can be critical information for setting national climate policies

Stress-Dependent Magnetoimpedance in Co-Based Amorphous Wires and Application to Tunable Microwave Composites

A remarkably strong dependence of magnetoimpedance (MI) on tensile stress has been observed in the microwave frequency range for thin CoMnSiB glass-coated microwires exposed to a special thermal treatment. The MI ratio runs into more than 100% at 0.5-1.5 GHz when the tensile stress of 600 MPa is applied to the wire. It was demonstrated that a large MI change at such high frequencies is related predominantly with the dc magnetization orientation. A host of such microwires incorporated into a dielectric matrix may constitute a new sensing medium that is characterized by the stress-dependent effective permittivity. Such medium can be used for the microwave visualization of the stress distribution inside of a composite structure or on its surface.Comment: The Intermag Conference 2005, Nagoya, Japa