667 research outputs found

    Coinvariant algebras and fake degrees for spin Weyl groups of classical type

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    The coinvariant algebra of a Weyl group plays a fundamental role in several areas of mathematics. The fake degrees are the graded multiplicities of the irreducible modules of a Weyl group in its coinvariant algebra, and they were computed by Steinberg, Lusztig and Beynon-Lusztig. In this paper we formulate a notion of spin coinvariant algebra for every Weyl group. Then we compute all the spin fake degrees for each classical Weyl group, which are by definition the graded multiplicities of the simple modules of a spin Weyl group in the spin coinvariant algebra. The spin fake degrees for the exceptional Weyl groups are given in a sequel.Comment: v2, 39 pages, title modified (with "of classical type" added), the original version was split into two parts following editor's suggestion; this v2 is the part one (to appear in Math. Proc. Cambridge Philos. Soc.), with a sequel dealing with the exceptional typ

    Accounting For The Benefits Of Database Normalization

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    This paper proposes a teaching approach to reinforce accounting students’ understanding of the concept of database normalization. Unlike a conceptual approach shown in most of the AIS textbooks, this approach involves with calculations and reconciliations with which accounting students are familiar because the methods are frequently used in accounting courses. The approach gives students the opportunity to justify the changes made to database structure during the database normalization process in terms of its efficiency and effectiveness. Further, the justification will help students realize and understand the purpose and benefits of database normalization. Instructors can easily adopt this approach to any of their own exercises used to cover database normalization concept

    The Effects of Erythropoietin Dose Titration during High-Fat Diet-Induced Obesity

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    Erythropoietin (Epo) is a pleotropic cytokine with several nonhematopoietic tissue effects. High-dose Epo treatment-mediated effects on body weight, fat mass and glucose tolerance have recently been reported, thus extending its pleotropic effects to fat and glucose metabolism. However, the exact dose range of Epo treatment required for such effects remains unidentified to date. We investigated Epo dosage effect (up to 1000 U/kg) on hematocrit, body weight, body composition, glucose metabolism, food intake, and physical activity, during high-fat diet-induced obesity. We report that Epo doses (1000, 600, 300, and 150 U/kg) significantly reduced body weight gain and fat mass, while, only Epo doses of 300 U/kg and higher significantly affected glucose tolerance. None of the tested Epo doses showed any detectable effects on food intake, and only 1000 U/kg dose significantly increased physical activity, suggesting that these parameters may only be partially responsible for the metabolic effects of Epo treatment

    Partial Structure and Mapping of the Human Myelin P 2 Protein Gene

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    The myelin P 2 protein, a 14,800-Da cytosolic protein found primarily in peripheral nerves, belongs to a family of fatty acid binding proteins. Although it is similar in amino acid sequence and tertiary structure to fatty acid binding proteins found in the liver, adipocytes, and intestine, its expression is limited to the nervous system. It is detected only in myelin-producing cells of the central and peripheral nervous systems, i.e., the oligodendrocytes and Schwann cells, respectively. As part of a program to understand the regulation of expression of this gene, to determine its function in myelin-producing cells, and to study its role in peripheral nerve disease, we have isolated and characterized overlapping human genomic clones encoding the P 2 protein. We report here on the partial structure of this gene, and on its localization within the genome. By using a panel of human-hamster somatic cell hybrids and by in situ hybridization, we have mapped the human P 2 gene to segment q21 on the long arm of chromosome 8. This result identifies the myelin P 2 gene as a candidate gene for autosomal recessive Charcot-Marie-Tooth disease type 4A.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65484/1/j.1471-4159.1994.63062010.x.pd

    A Prospective Controlled Trial of an Electronic Hand Hygiene Reminder System

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    Background. The use of electronic hand hygiene reminder systems has been proposed as an approach to improve hand hygiene compliance among healthcare workers, although information on efficacy is limited. We prospectively assessed whether hand hygiene activities among healthcare workers could be increased using an electronic hand hygiene monitoring and reminder system. Methods. A prospective controlled clinical trial was conducted in 2 medical intensive care units (ICUs) at an academic medical center with comparable patient populations, healthcare staff, and physical layout. Hand hygiene activity was monitored concurrently in both ICUs, and the reminder system was installed in the test ICU. The reminder system was tested during 3 administered phases including: room entry/exit chimes, display of real-time hand hygiene activity, and a combination of the 2. Results. In the test ICU, the mean number of hand hygiene events increased from 1538 per day at baseline to 1911 per day (24% increase) with the use of a combination of room entry/exit chimes, real-time displays of hand hygiene activity, and manager reports (P \u3c .001); in addition, the ratio of hand hygiene to room entry/exit events also increased from 26.1% to 36.6% (40% increase, P \u3c .001). The performance returned to baseline (1473 hand hygiene events per day) during the follow-up phase. There was no significant change in hand hygiene activity in the control ICU during the course of the trial. Conclusions. In an ICU setting, an electronic hand hygiene reminder system that provided real-time feedback on overall unit-wide hand hygiene performance significantly increased hand hygiene activity

    Chromophore supply modulates cone function and survival in retinitis pigmentosa mouse models.

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    Retinitis pigmentosa (RP) is an ocular disease characterized by the loss of night vision, followed by the loss of daylight vision. Daylight vision is initiated in the retina by cone photoreceptors, which are gradually lost in RP, often as bystanders in a disease process that initiates in their neighboring rod photoreceptors. Using physiological assays, we investigated the timing of cone electroretinogram (ERG) decline in RP mouse models. A correlation between the time of loss of the cone ERG and the loss of rods was found. To investigate a potential role of the visual chromophore supply in this loss, mouse mutants with alterations in the regeneration of the retinal chromophore, 11-cis retinal, were exam- ined. Reducing chromophore supply via mutations in Rlbp1 or Rpe65 resulted in greater cone function and survival in a RP mouse model. Conversely, overexpression of Rpe65 and Lrat, genes that can drive the regeneration of the chromophore, led to greater cone degeneration. These data suggest that abnormally high chromophore supply to cones upon the loss of rods is toxic to cones, and that a potential therapy in at least some forms of RP is to slow the turnover and/or reduce the level of visual chromophore in the retina

    Erythropoietin and hypoxia increase erythropoietin receptor and nitric oxide levels in lung microvascular endothelial cells

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    Acute lung exposure to low oxygen results in pulmonary vasoconstriction and redistribution of blood flow. We used human microvascular endothelial cells from lung (HMVEC-L) to study the acute response to oxygen stress. We observed that hypoxia and erythropoietin (EPO) increased erythropoietin receptor (EPOR) gene expression and protein level in HMVEC-L In addition, EPO dose- and time-dependently stimulated nitric oxide (NO) production. This NO stimulation was evident despite hypoxia induced reduction of endothelial NO synthase (eNOS) gene expression. Western blot of phospho-eNOS (serine1177) and eNOS and was significantly induced by hypoxia but not after EPO treatment. However, iNOS increased at hypoxia and with EPO stimulation compared to normal oxygen tension. In accordance with our previous results of NO induction by EPO at low oxygen tension in human umbilical vein endothelial cells and bone marrow endothelial cells, these results provide further evidence in HMVEC-L for EPO regulation of NO production to modify the effects of hypoxia and cause compensatory vasoconstriction
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