36,536 research outputs found
Branching Asymptotics on Manifolds with Edge
We study pseudo-differential operators on a wedge with continuous and
variable discrete branching asymptotics.Comment: 54 pages, 1 figure
Accurate on-wafer power and harmonic measurements of mm-wave amplifiers and devices
A novel integrated test system that accurately measures on-wafer S-parameters, power levels, load-pull contours and harmonics over 1 to 50 GHz is presented. The system measures power and S-parameters with single contact measurements and integrated hardware. There are two keys to this system: first, the network analyzer samplers are used as frequency-selective power meters with large dynamic ranges; second, all measurements are vector-corrected to the device under test reference planes. The capabilities and accuracy were demonstrated by measuring the power at the fundamental frequency and four harmonic frequencies of a 50-GHz traveling wave amplifier and the load-pull contours of a MODFET at 30 GH
Companions of Qsos at Redshift 1.1
We discuss broad- and narrow-band imaging of 7 arcmin fields of 14 QSOs with
redshift ~1.1. The narrow-band filters were chosen to detect redshifted [O II]
3727A, and the broad bands are R and I, which correspond to rest wavelengths
{}~3300A and ~3800A. In 100 arcsec subfields surrounding the QSOs, we detect an
excess of typically 15 detected objects over the background of 25. Several of
the QSO subfields also contain an excess of blue (R-I < 1.0) galaxies compared
with the other subfields. Finally, several of the QSO subfields contain an
excess of galaxies with significant narrow-band flux compared with the other
subfields, and many of these are also blue. Most of the QSOs are radio-quiet in
a region of sky overpopulated with z=1.1 QSOs, and 3 others are radio-loud from
other parts of the sky. We suggest that most of these z=1.1 QSOs are in compact
groups of starbursting galaxies. In our data, there is no significant
difference between radio-loud and radio-quiet QSOs. We discuss cosmic
evolutionary implications.Comment: 9 pages Plain Tex, 8 figures upon request, SISSA-DAO-94-00
On the identification of the âmiddle classâ
The paper examines the identification of the âmiddle classâ using data from LIS and LWS. It first considers definitions based purely on income, examining the rationale for different approaches and illustrating the implications for changes over time. It argues that the concept of âclassâ requires the examination of other dimensions beyond income. The paper considers the role of property and, drawing on the sociological literature, of occupations.class structure, income distribution
On analysing the world distribution of income
This paper argues that consideration of world inequality should cause us to re-examine the key concepts underlying the welfare approach to the measurement of income inequality and the inter-relation between the measurement of inequality and the measurement of poverty. There are three reasons why we feel that a re-examination is necessary: (i) the extent of global income differences means that we cannot simply carry over the methods used at a national level; we need a more flexible measure; (ii) we have to reconcile measures of world inequality and world poverty; and (iii) we need to explore more fully the different ways in which measures may be relative or absolute. This leads us to propose a new measure, which (a) combines poverty and inequality, including provision for those who are concerned only with poverty, (b) incorporates different approaches to the measurement of inequality; and (c) allows the cost of inequality to be expressed in different ways. Applied to the world distribution for the period 1820-1992, the new measure provides different perspectives on the evolution of global inequality.global income inequality, absolute vs. relative inequality, poverty, world citizens
ADAM15 modulates outside-in signalling in chondrocyteâmatrix interactions
ADAM15 belongs to a family of transmembrane multi-domain proteins implicated in proteolysis, cellâcell and cellâmatrix interactions in various disease conditions. In osteoarthritis (OA), ADAM15 is up-regulated in the chondrocytes already at early stages of cartilage degeneration where it seems to exert homeostatic effects likely associated with its ability to enhance integrin-mediated chondrocyte adhesion to the surrounding collagen matrix. The aim of our present study was, therefore, to characterize functional domains of ADAM15 involved in collagen II (CII) interaction and to analyse associated outside-in signalling events. Accordingly, ADAM15 and respective deletion mutants were stably transfected into the chondrocyte cell line T/C28a4. Transfected cells were adhered to CII and phosphoproteins analysed by Western blotting. Co-immunoprecipitation served to identify protein binding to ADAM15. Our results elucidate the prodomain as critical for the capacity of ADAM15 to enhance CII adhesion, thereby identifying for the first time a cell-adhesive role of a metalloproteinase prodomain. Moreover, the cytoplasmic tail of ADAM15 confers a modulatory effect on the autophosphorylation site Y397 of the focal adhesion kinase (FAK) during chondrocyteâcollagen interaction. In conclusion, the newly uncovered impact of ADAM15 on signalling events that arise from chondrocyte interactions with its collagen matrix might contribute to the elucidation of the mechanism underlying its proposed chondroprotective role in degenerative cartilage disease
Critical Behavior of the Two-Dimensional Randomly Driven Lattice Gas
We investigate the critical behavior of the two-dimensional randomly driven
lattice gas, in which particles are driven along one of the lattice axes by an
infinite external field with randomly changing sign. A finite-size scaling
(FSS) analysis provides novel evidences that this model is not in the same
universality class as the driven lattice gas with a constant drive (DLG),
contrarily to what has been recently reported in the literature. Indeed, the
FSS functions of transverse observables (i.e., related to order-parameter
fluctuations with wave vector perpendicular to the direction of the field)
differ from the mean-field behavior predicted and observed within the DLG
universality class. At variance with the DLG case, FSS is attained on lattices
with fixed aspect ratio and anisotropy exponent equal to 1 and the transverse
Binder cumulant does not vanish at the critical point.Comment: 4 pages, 4 figure
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