576 research outputs found
Geometric Dilations and Operator Annuli
Fix 1<R. The dilation theory for the quantum annulus, consisting of those
invertible Hilbert space operators T such that the norm of T and its inverse
are both at most R is determined. The proof technique involves a geometric
approach to dilation that applies to other well known dilation theorems. The
dilation theory for the quantum annulus is compared, and contrasted, with the
dilation theory for other canonical operator annuli.Comment: V2. Corrected the attribution for Theorem 1.2. V3. Corrected the
proof of Theorem 1.1(c) plus some minor fixe
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Examination of Build Height in Ultrasonic Consolidation for Foil Width Specimens Using Supports
Ultrasonic consolidation (UC) is a novel, solid-state, additive manufacturing
fabrication process. It consists of ultrasonic joining of thin metal foils and contour milling
to directly produce functional components in a variety of geometries. The bond between
layers forms when an ultrasonic horn creates a local oscillating stress field at the mating
surfaces. It is commonly theorized that the high frequency vibration under pressure
produces a metallurgical bond without melting the base material. The mechanism behind
the bond is believed to be due to interfacial motion and friction that disrupts surface
contaminants, arguably allowing direct metal to metal contact, and producing sufficient
stress to induce plastic flow and promote the growth of grains across the mating surfaces.
Ignored in this explanation is the role of substrate dimensions on the quality and strength
of the joining process. Researchers have previously examined the effective height
limitations of the build process, i.e., the limiting height to width ratio of one of the
component features being fabricated. This paper extends the experimental work on using
support materials to extend build height on specimens using two different candidate materials, tin bismuth, and a mixture of sugar, corn syrup, and water, referred to as
âcandyâ. Tin bismuth and candy the represent the extremes of a tradeoff between
convenience and stiffness that a support material must possess.Mechanical Engineerin
Noncommutative partially convex rational functions
Motivated by classical notions of bilinear matrix inequalities (BMIs) and
partial convexity, this article investigates partial convexity for
noncommutative functions. It is shown that noncommutative rational functions
that are partially convex admit novel butterfly-type realizations that
necessitate square roots. The notion of xy-convexity, a strengthening of
partial convexity arising in connection with BMIs, is also considered. A
characterization of xy-convex polynomials is given
Treatment of chronically depressed patients: A multisite randomized controlled trial testing the effectiveness of \u27Cognitive Behavioral Analysis System of Psychotherapy\u27 (CBASP) for chronic depressions versus usual secondary care
Background
\u27Cognitive Behavioral Analysis System of Psychotherapy\u27 (CBASP) is a form of psychotherapy specifically developed for patients with chronic depression. In a study in the U.S., remarkable favorable effects of CBASP have been demonstrated. However, no other studies have as yet replicated these findings and CBASP has not been tested outside the United States. This protocol describes a randomized controlled trial on the effectiveness of CBASP in the Netherlands. Methods/Design
The purpose of the present paper is to report the study protocol of a multisite randomized controlled trial testing the effectiveness of \u27Cognitive Behavioral Analysis System of Psychotherapy\u27 (CBASP) for chronic depression in the Netherlands. In this study, CBASP in combination with medication, will be tested versus usual secondary care in combination with medication. The aim is to recruit 160 patients from three mental health care organizations. Depressive symptoms will be assessed at baseline, after 8 weeks, 16 weeks, 32 weeks and 52 weeks, using the 28-item Inventory for Depressive Symptomatology (IDS). Effect modification by co morbid anxiety, alcohol consumption, general and social functioning and working alliance will be tested. GEE analyses of covariance, controlling for baseline value and center will be used to estimate the overall treatment effectiveness (difference in IDS score) at post-treatment and follow up. The primary analysis will be by \u27intention to treat\u27 using double sided tests. An economic analysis will compare the two groups in terms of mean costs and cost-effectiveness from a societal perspective. Discussion
The study will provide an answer to the question whether the favorable effects of CBASP can be replicated outside the US. Trial Registration
The Dutch Cochrane Center, NTR1090
Characterisation of the Immunophenotype of Dogs with Primary Immune-Mediated Haemolytic Anaemia
Immune-mediated haemolytic anaemia (IMHA) is reported to be the most common autoimmune disease of dogs, resulting in significant morbidity and mortality in affected animals. Haemolysis is caused by the action of autoantibodies, but the immunological changes that result in their production have not been elucidated.To investigate the frequency of regulatory T cells (Tregs) and other lymphocyte subsets and to measure serum concentrations of cytokines and peripheral blood mononuclear cell expression of cytokine genes in dogs with IMHA, healthy dogs and dogs with inflammatory diseases.19 dogs with primary IMHA, 22 dogs with inflammatory diseases and 32 healthy control dogs.Residual EDTA-anti-coagulated blood samples were stained with fluorophore-conjugated monoclonal antibodies and analysed by flow cytometry to identify Tregs and other lymphocyte subsets. Total RNA was also extracted from peripheral blood mononuclear cells to investigate cytokine gene expression, and concentrations of serum cytokines (interleukins 2, 6 10, CXCL-8 and tumour necrosis factor α) were measured using enhanced chemiluminescent assays. Principal component analysis was used to investigate latent variables that might explain variability in the entire dataset.There was no difference in the frequency or absolute numbers of Tregs among groups, nor in the proportions of other lymphocyte subsets. The concentrations of pro-inflammatory cytokines were greater in dogs with IMHA compared to healthy controls, but the concentration of IL-10 and the expression of cytokine genes did not differ between groups. Principal component analysis identified four components that explained the majority of the variability in the dataset, which seemed to correspond to different aspects of the immune response.The immunophenotype of dogs with IMHA differed from that of dogs with inflammatory diseases and from healthy control dogs; some of these changes could suggest abnormalities in peripheral tolerance that permit development of autoimmune disease. The frequency of Tregs did not differ between groups, suggesting that deficiency in the number of these cells is not responsible for development of IMHA
First results of a study of TeV emission from GRBs in Milagrito
Milagrito, a detector sensitive to Îł-rays at TeV energies, monitored the northern sky during the period February 1997 through May 1998. With a large field of view and high duty cycle, this instrument was used to perform a search for TeV counterparts to Îł-ray bursts. Within the Milagrito field of view 54 Îł-ray bursts at keV energies were observed by the Burst And Transient Satellite Experiment (BATSE) aboard the Compton Gamma-Ray Observatory. This paper describes the results of a preliminary analysis to search for TeV emission correlated with BATSE detected bursts. Milagrito detected an excess of events coincident both spatially and temporally with GRB 970417a, with chance probability 2.8Ă10â5 within the BATSE error radius. No other significant correlations were detected. Since 54 bursts were examined the chance probability of observing an excess with this significance in any of these bursts is 1.5Ă10â3. The statistical aspects and physical implications of this result are discussed
Milagro: A TeV gamma-ray monitor of the Northern Hemisphere Sky
A new type of very high energy (\u3e a few 100 GeV) gamma-ray observatory, Milagro, has been built with a large field of view of \u3e1 steradian and nearly 24 hours/day operation. Milagrito, a prototype for Milagro, was operated from February 1997 to May 1998. During the summer of 1998, Milagrito was dismantled and Milagro was built. Both detectors use a 80âmĂ60âmĂ8âmpond of water in which a 3âmĂ3âm grid of photomultiplier tubes detects the Cherenkov light produced in the water by the relativistic particles in extensive air showers. Milagrito was smaller and had only one layer of photomultipliers, but allowed the technique to be tested. Milagrito observations of the Moonâs shadow and Mrk 501 are consistent with the Monte Carlo prediction of the telescopes parameters, such as effective area and angular resolution. Milagro is larger and consists of two layers of photomultiplier tubes. The bottom layer detects penetrating particles that are used to reject the background of cosmic-ray initiated showers
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