2,873 research outputs found

    On Fields with Finite Information Density

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    The existence of a natural ultraviolet cutoff at the Planck scale is widely expected. In a previous Letter, it has been proposed to model this cutoff as an information density bound by utilizing suitably generalized methods from the mathematical theory of communication. Here, we prove the mathematical conjectures that were made in this Letter.Comment: 31 pages, to appear in Phys.Rev.

    Natriuretic peptide receptor-C is up-regulated in the intima of advanced carotid artery atherosclerosis

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    OBJECTIVE: Natriuretic peptide receptor-C (NPR-C/NPR-3) is a cell surface protein involved in vascular remodelling that is up-regulated in atherosclerosis. NPR-C expression has not been well characterized in human carotid artery occlusive lesions. We hypothesized that NPR-C expression correlates with intimal features of vulnerable atherosclerotic carotid artery plaque. METHODS: To test this hypothesis, we evaluated NPR-C expression by immunohistochemistry (IHC) in carotid endarterectomy (CEA) specimens isolated from 18 patients. The grade, location, and co-localization of NPR-C in CEA specimens were evaluated using two tissue analysis techniques. RESULTS: Relative to minimally diseased CEA specimens, we observed avid NPR-C tissue staining in the intima of maximally diseased CEA specimens (65%; p=0.06). Specifically, maximally diseased CEA specimens demonstrated increased NPR-C expression in the superficial intima (61%, p=0.17), and deep intima (138% increase; p=0.05). In the superficial intima, NPR-C expression significantly co-localized with vascular smooth muscle cells (VSMCs) and macrophages. The intensity of NPR-C expression was also higher in the superficial intima plaque shoulder and cap regions, and significantly correlated with atheroma and fibroatheroma vulnerable plaque regions (β=1.04, 95% CI=0.46, 1.64). CONCLUSION: These findings demonstrate significant NPR-C expression in the intima of advanced carotid artery plaques. Furthermore, NPR-C expression was higher in vulnerable carotid plaque intimal regions, and correlate with features of advanced disease. Our findings suggest that NPR-C may serve as a potential biomarker for carotid plaque vulnerability and progression, in patients with advanced carotid artery occlusive disease

    Combined sanger and ngs sequence analysis of the myostatin gene (mstn) in the Camelus dromedarius species

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    Different mutations have been identified in the myostatin gene (MSTN), some of which are responsible for protein inactivation and double muscling phenotype in mammals. So far, no extensive polymorphism survey has been carried out in Camelus dromedarius. We therefore performed a sequence analysis, adopting a combined strategy involving Sanger and next generation sequencing (NGS). Notably, 3.6 kb of the MSTN locus were Sanger sequenced in a population dataset including samples from Algeria (10), Tunisia (5), Egypt (9), Mauritania (5), Sudan (5) and Saudi Arabia (9). A further wholegenome dataset, including 7 C. dromedarius from Pakistan (1), Kenya (1), Saudi Arabia (3), Canary Islands (1) and Oman (1) were sequenced using the Illumina Hi-Seq 2000 technique at an average 15-fold coverage. Whole-genome NGS sequence data from 9 C. bactrianus and 7 C. ferus samples were also available for comparison. Overall, only four polymorphisms were detected, all of them were observed in intronic regions, corresponding to an average presence of one SNP per 1200 bps. Ten fixed sites were observed when comparing C. dromedarius MSTN sequences with those from C. bactrianus and C. ferus. The apparent low sequence diversity observed at the MSTN locus may reflect the peculiar evolutionary history of this species, with purifying selection and drift phenomena as the most likely acting forces.(Résumé d'auteur

    A study of the gravitational wave form from pulsars II

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    We present analytical and numerical studies of the Fourier transform (FT) of the gravitational wave (GW) signal from a pulsar, taking into account the rotation and orbital motion of the Earth. We also briefly discuss the Zak-Gelfand Integral Transform. The Zak-Gelfand Integral Transform that arises in our analytic approach has also been useful for Schrodinger operators in periodic potentials in condensed matter physics (Bloch wave functions).Comment: 6 pages, Sparkler talk given at the Amaldi Conference on Gravitational waves, July 10th, 2001. Submitted to Classical and Quantum Gravit

    Patient characteristics can influence the incidence of perioperative microemboli during carotid artery interventions

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    Purpose. Perioperative cerebral microembolization demonstrated on diffusion-weighted MRI (DWI) can occur following carotid endarterectomy (CEA) and carotid artery stenting (CAS). We sought to explore potential risk factors for this in the large patient cohort. Methods. We reviewed a 6-year consecutive patient cohort that received either CEA or CAS, and perioperative DWI evaluations. Results. 303 patients were reviewed, and 56 (19.4%) patients were found to have perioperative microemboli. The incidence was higher among patients who received CAS (P &lt; 0.001). Hypertension (P = 0.03), smoking (P = 0.001), and a history of transient ischemic attacks (P = 0.04) were risk factors for microembolization. The risk was higher among CEA patients with obesity (P = 0.05), and among CAS patients with coronary artery disease (P = 0.03). Conclusion. Specific patient populations are likely more prone to develop perioperative cerebral microemboli following carotid intervention. Continued risk stratification may help decrease future perioperative cerebral microembolization rates.</jats:p

    The Zero-Removing Property and Lagrange-Type Interpolation Series

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    The classical Kramer sampling theorem, which provides a method for obtaining orthogonal sampling formulas, can be formulated in a more general nonorthogonal setting. In this setting, a challenging problem is to characterize the situations when the obtained nonorthogonal sampling formulas can be expressed as Lagrange-type interpolation series. In this article a necessary and sufficient condition is given in terms of the zero removing property. Roughly speaking, this property concerns the stability of the sampled functions on removing a finite number of their zeros
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