Subquotients of UHF C*-algebras

1994 ◽  
Vol 115 (3) ◽  
pp. 489-500 ◽  
Author(s):  
Simon Wassermann

Over the last thirty years, the study of C*-algebras has proceeded in a number of directions. On one hand, much effort has been devoted to understanding the structure of particular classes of algebras, such as the approximately finite (AF) algebras. On the other, general structure theorems have been sought. Classes of algebras defined by certain abstract properties have been investigated with a view to obtaining more concrete descriptions of the algebras. One of the earliest results of this type was the theorem of Glimm [13], later extended by Sakai [20] to the inseparable case, characterizing the non-type I C*-algebras as those algebras which contain a subalgebra with a quotient *-isomorphic to the CAR algebra.

2015 ◽  
Vol 117 (1) ◽  
pp. 105 ◽  
Author(s):  
Ilijas Farah ◽  
Takeshi Katsura

For every uncountable cardinal $\kappa$ there are $2^\kappa$ nonisomorphic simple AF algebras of density character $\kappa$ and $2^\kappa$ nonisomorphic hyperfinite ${\rm II}_1$ factors of density character $\kappa$. These estimates are maximal possible. All C*-algebras that we construct have the same Elliott invariant and Cuntz semigroup as the CAR algebra.


Author(s):  
Abraham A. Singer

This chapter introduces the main argument of the book, describing key concepts such as the idea of “norm-governed productivity,” the use of norms to structure cooperation instead of prices. It then defines the concept of the corporation, describing the institution’s key features, and lays out the general structure of the book. Finally, it considers some conceptual and methodological issues that frame the rest of the book: the distinction between economic and political approaches, and the problem of trying to subsume the topic wholly into one or the other; and an argument for why a normative analysis of the corporation has to take certain features of markets and capitalism for granted.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 329
Author(s):  
Andrew Holmes ◽  
Jessie Sadlon ◽  
Keith Weaver

A majority of toxins produced by type I toxin–antitoxin (TA-1) systems are small membrane-localized proteins that were initially proposed to kill cells by forming non-specific pores in the cytoplasmic membrane. The examination of the effects of numerous TA-1 systems indicates that this is not the mechanism of action of many of these proteins. Enterococcus faecalis produces two toxins of the Fst/Ldr family, one encoded on pheromone-responsive conjugative plasmids (FstpAD1) and the other on the chromosome, FstEF0409. Previous results demonstrated that overexpression of the toxins produced a differential transcriptomic response in E. faecalis cells. In this report, we identify the specific amino acid differences between the two toxins responsible for the differential response of a gene highly induced by FstpAD1 but not FstEF0409. In addition, we demonstrate that a transporter protein that is genetically linked to the chromosomal version of the TA-1 system functions to limit the toxicity of the protein.


2001 ◽  
Vol 38 (02) ◽  
pp. 542-553 ◽  
Author(s):  
Ji Hwan Cha

In this paper two burn-in procedures for a general failure model are considered. There are two types of failure in the general failure model. One is Type I failure (minor failure) which can be removed by a minimal repair or a complete repair and the other is Type II failure (catastrophic failure) which can be removed only by a complete repair. During a burn-in process, with burn-in Procedure I, the failed component is repaired completely regardless of the type of failure, whereas, with burn-in Procedure II, only minimal repair is done for the Type I failure and a complete repair is performed for the Type II failure. In field use, the component is replaced by a new burned-in component at the ‘field use age’ T or at the time of the first Type II failure, whichever occurs first. Under the model, the problems of determining optimal burn-in time and optimal replacement policy are considered. The two burn-in procedures are compared in cases when both the procedures are applicable.


1979 ◽  
Vol 4 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Juliet Popper Shaffer

If used only when a preliminary F test yields significance, the usual multiple range procedures can be modified to increase the probability of detecting differences without changing the control of Type I error. The modification consists of a reduction in the critical value when comparing the largest and smallest means. Equivalence of modified and unmodified procedures in error control is demonstrated. The modified procedure is also compared with the alternative of using the unmodified range test without a preliminary F test, and it is shown that each has advantages over the other under some circumstances.


1995 ◽  
Vol 89 (1) ◽  
pp. 69-73 ◽  
Author(s):  
Andrew E. Pocock ◽  
Martin J. O. Francis ◽  
Roger Smith

1. Skin fibroblast lines were cultured from nine patients who had the features of idiopathic juvenile osteoporosis, six relatives, five unrelated control subjects and three unrelated patients with osteogenesis imperfecta type I. Some patients with idiopathic juvenile osteoporosis were adults whose previous osteoporosis was in remission. Two patients with idiopathic juvenile osteoporosis were siblings and one patient with idiopathic juvenile osteoporosis had a daughter with severe osteogenesis imperfecta (type III). 2. The ratio of type III to type I collagen, synthesized by fibroblasts, was increased in two of the patients with osteogenesis imperfecta type I and in the daughter with osteogenesis imperfecta type III, but was normal in all the other patients with idiopathic juvenile osteoporosis and the other relatives. 3. Radiolabelled collagen was digested by cyanogen bromide and separated on SDS-PAGE. Unreduced collagen peptides migrated normally, except those from both the two siblings with idiopathic juvenile osteoporosis. In these two lines, abnormal migration suggested the presence of collagen I mutations. 4. The secretion of synthesized collagen by these two idiopathic juvenile osteoporosis lines and two others was reduced to only 43–45% as compared with a line from a 13-year-old control subject, which was defined as 100%. The three osteogenesis imperfecta type I lines secreted 18–37%, the other five idiopathic juvenile osteoporosis lines secreted 57–75%, the relatives (including the daughter with severe osteogenesis imperfecta) secreted 49–115% and the controls secreted 69–102%. 5. We conclude that qualitative abnormalities of type I collagen associated with a reduction in total secreted collagen synthesis may occur in a minority of patients with idiopathic juvenile osteoporosis; these patients could represent a subset of patients with this disorder.


2021 ◽  
Vol 34 (1) ◽  
pp. 79-88
Author(s):  
Dean Radin ◽  
Helané Wahbeh ◽  
Leena Michel ◽  
Arnaud Delorme

An experiment we conducted from 2012 to 2013, which had not been previously reported, was designed to explore possible psychophysical effects resulting from the interaction of a human mind with a quantum system. Participants focused their attention toward or away from the slits in a double-slit optical system to see if the interference pattern would be affected. Data were collected from 25 people in individual half-hour sessions; each person repeated the test ten times for a total of 250 planned sessions. “Sham” sessions designed to mimic the experimental sessions without observers present were run immediately before and after as controls. Based on the planned analysis, no evidence for a psychophysical effect was found. Because this experiment differed in two essential ways from similar, previously reported double-slit experiments, two exploratory analyses were developed, one based on a simple spectral analysis of the interference pattern and the other based on fringe visibility. For the experimental data, the outcome supported a pattern of results predicted by a causal psychophysical effect, with the spectral metric resulting in a 3.4 sigma effect (p = 0.0003), and the fringe visibility metric resulting in 7 of 22 fringes tested above 2.3 sigma after adjustment for type I error inflation, with one of those fringes at 4.3 sigma above chance (p = 0.00001). The same analyses applied to the sham data showed uniformly null outcomes. Other analyses exploring the potential that these results were due to mundane artifacts, such as fluctuations in temperature or vibration, showed no evidence of such influences. Future studies using the same protocols and analytical methods will be required to determine if these exploratory results are idiosyncratic or reflect a genuine psychophysical influence.


2013 ◽  
Vol 65 (1) ◽  
pp. 52-65
Author(s):  
Erik Christensen ◽  
Allan M. Sinclair ◽  
Roger R. Smith ◽  
Stuart White
Keyword(s):  
Type I ◽  

AbstractIn this paper we consider near inclusions of C*-algebras. We show that if B is a separable type I C*-algebra and A satisfies Kadison's similarity problem, then A is also type I. We then use this to obtain an embedding of A into B.


2019 ◽  
Vol 26 (6) ◽  
pp. 782-786 ◽  
Author(s):  
Ahmed Eleshra ◽  
Tilo Kölbel ◽  
Nikolaos Tsilimparis ◽  
Giuseppe Panuccio ◽  
Martin Scheerbaum ◽  
...  

Purpose: To present the early results of false lumen (FL) occlusion in chronic aortic dissection using the Candy-Plug generation II (CP II), which has a self-closing fabric channel that obviates the need for separate occlusion of its center. Materials and Methods: Fourteen consecutive patients (mean age 60±11 years; 10 men) with persistent FL backflow and aneurysm formation at the thoracic segment in chronic aortic dissection underwent thoracic endovascular aortic repair (TEVAR) with FL occlusion using the refined CP II. Primary endpoints were technical success (successful deployment) and clinical success (no FL backflow at the CP II level). Secondary endpoints included 30-day mortality and morbidity and aortic remodeling during follow-up. Results: Technical success was 100%. One patient required additional intraprocedural FL embolization at the CP II level due to persistent FL backflow on final angiography (clinical success 93%), though there was no flow through the CP II center. There were no intraprocedural complications. Immediate complete FL occlusion was achieved in 12 patients; the other 2 required reintervention. One had contrast enhancement in the distal FL proximal to the CP II and was treated with coil embolization. The other patient had persistent type I endoleak at the level of the left subclavian artery (LSA) and underwent left carotid–LSA bypass and proximal stent-graft extension. One patient died due to retrograde type A aortic dissection that was not related to CP II placement. Over a mean 8-month follow-up (range 3–12), 9 patients had computed tomography angiography; 8 patients had evidence of aortic remodeling, while 1 aneurysm sac was stable. Conclusion: The CP II reduces the number of procedural steps and offers good seal, with minimal morbidity and mortality and a high rate of aortic remodeling.


2009 ◽  
Vol 390 (9) ◽  
Author(s):  
Sylvie Desmarais ◽  
Frédéric Massé ◽  
M. David Percival

Abstract Cathepsin K (Cat K) degrades bone type I collagen and is a target for the pharmacological treatment of osteoporosis. Further roles for Cat K have been recently described, some of which are supported by the use of purportedly selective Cat K inhibitors in human and rodent cell-based assays. Twelve commercial and non-commercial Cat K inhibitors were profiled against a panel of purified human, rat, and mouse cysteine cathepsins and in two cell-based enzyme occupancy assays for activity against Cat K, B, and L. Ten inhibitors, including the carbohydrazide Cat K inhibitor II (Boc-Phe-Leu-NHNH-CO-NHNH-Leu-Z), the non-covalent K4b, and the epoxide NC-2300, have either little Cat K selectivity, or appear poorly cell penetrant. The amino-acetonitrile-containing inhibitors L-873724 and odanacatib show greater than 100-fold human Cat K enzyme selectivity and have similar IC50 values against each cathepsin in cell-based and enzyme assays. The basic inhibitor balicatib has greater cellular potencies than expected on the basis of purified enzyme assays. The accumulation of [14C]-balicatib in fibroblasts is blocked by prior treatment of the cells with NH4Cl, consistent with balicatib having lysosomotropic properties. These results support the use of L-873724 and odanacatib as tools to identify novel roles for Cat K using human cell-based systems, but suggest using caution in the interpretation of studies employing the other compounds.


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