1,217 research outputs found
Effects of C-peptide on Microvascular Blood Flow and Blood Hemorheology
Beside functional and structural changes in vascular biology,
alterations in the rheologic properties of blood cells
mainly determines to an impaired microvascular blood
flow in patients suffering from diabetes mellitus. Recent
investigations provide increasing evidence that impaired
C-peptide secretion in type 1 diabetic patients might contribute
to the development of microvascular complications.
C-peptide has been shown to stimulate endothelial
NO secretion by activation of the Ca2+ calmodolin regulated
enzyme eNOS. NO himself has the potency to increase
cGMP levels in smooth muscle cells and to activate
Na+ K+ ATPase activity and therefore evolves numerous effects
in microvascular regulation. In type 1 diabetic patients,
supplementation of C-peptide was shown to improve endothelium
dependent vasodilatation in an NO-dependent
pathway in different vascular compartments. In addition,
it could be shown that C-peptide administration in type 1
diabetic patients, results in a redistribution of skin blood
flow by increasing nutritive capillary blood flow in favour
to subpapillary blood flow. Impaired Na+ K+ ATPase in another
feature of diabetes mellitus in many cell types and
is believed to be a pivotal regulator of various cell functions.
C-peptide supplementation has been shown to restore
Na+ K+ATPase activity in different cell types during
in vitro and in vivo investigations. In type 1 diabetic patients,
C-peptide supplementation was shown to increase
erythrocyte Na+ K+ATPase activity by about 100%. There
was found a linear relationship between plasma C-peptide
levels and erythrocyte Na+ K+ATPase activity. In small
capillaries, microvascular blood flow is increasingly determined
by the rheologic properties of erythrocytes. Using laser-diffractoscopie a huge improvement in erythrocyte deformability
could be observed after C-peptide administration
in erythrocytes of type 1 diabetic patients. Inhibition
of the Na+ K+ATPase by Obain completely abolished the
effect of C-peptide on erythrocyte deformability. In conclusion,
C-peptide improves microvascular function and blood
flow in type 1 diabetic patients by interfering with vascular
and rheological components of microvascular blood flow
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Is Small Beautiful? Financial Structure, Size and Access to Finance
Combining two unique data sets, this paper explores the relationship between financial structure and firms’ access to financial services. Specifically, it considers the importance of three different types of financial institutions: low-end financial institutions, specialized lenders, and banks. Two findings stand out. First, dominance of the financial system by banks is associated with lower use of financial services by firms of all sizes, while low-end financial institutions and specialized lenders seem particularly suited to ease access to finance in low-income countries. Second, there is no evidence that smaller institutions are better in providing access to financ
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Financing patterns around the world: Are small firms different?
Using a firm-level survey database covering 48 countries, we investigate how financial and institutional development affects financing of large and small firms. Our database is not limited to large firms but includes small and medium-size firms and data on a broad spectrum of financing sources, including leasing, supplier, development, and informal finance. Small firms and firms in countries with poor institutions use less external finance, especially bank finance. Protection of property rights increases external financing of small firms significantly more than of large firms, mainly due to its effect on bank finance. Small firms do not use disproportionately more leasing or trade finance compared with larger firms, so these financing sources do not compensate for lower access to bank financing of small firms. We also find that larger firms more easily expand external financing when they are constrained than small firms. Finally, we find suggestive evidence that the pecking order holds across countries
Visual Data Compression for Multimedia Applications
The compression of visual information in the framework of multimedia applications is discussed. To this end, major approaches to compress still as well as moving pictures are reviewed. The most important objective in any compression algorithm is that of compression efficiency. High-compression coding of still pictures can be split into three categories: waveform, second-generation, and fractal coding techniques. Each coding approach introduces a different artifact at the target bit rates. The primary objective of most ongoing research in this field is to mask these artifacts as much as possible to the human visual system. Video-compression techniques have to deal with data enriched by one more component, namely, the temporal coordinate. Either compression techniques developed for still images can be generalized for three-dimensional signals (space and time) or a hybrid approach can be defined based on motion compensation. The video compression techniques can then be classified into the following four classes: waveform, object-based, model-based, and fractal coding techniques. This paper provides the reader with a tutorial on major visual data-compression techniques and a list of references for further information as the details of each metho
Bankers on the Board and CEO Turnover
The governance literature finds that independent directors from lending banks (commercial bank directors or CBDs) bring both financial expertise and conflict of interest between shareholders and debt holders. We examine how the presence of CBDs affects the implicit incentive of CEO turnover. Using BoardEx and DealScan data, we hypothesize and find that CBDs make the CEO turnover more sensitive to both performance and risk. Postâ CEO turnover analysis reveals that firm performance improves and risk decreases in the presence of CBDs.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154485/1/ajfs12288_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154485/2/ajfs12288.pd
An integrated vapor source with a porous silicon wick
A micro vapor source has been developed for calibrating micro gas chromatograph (ΜGC) systems. By utilizing a porous silicon wick in a micro diffusion system, vapor generation with excellent stability has been achieved. The source has shown uniform and repeatable vapor generation for n-decane with less than a 0.1% variation in 9 hours, and less than a 0.5% variation in rate over 7 days. The evolution rate follows the diffusion model as expected, although the room temperature rate is higher than theoretically predicted. Equipped with a refillable reservoir, this vapor source is suitable for extended ΜGC field deployment. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56056/1/1449_ftp.pd
High-performance compression of visual information - A tutorial review - Part I : Still Pictures
Digital images have become an important source of information in the modern world of communication systems. In their raw form, digital images require a tremendous amount of memory. Many research efforts have been devoted to the problem of image compression in the last two decades. Two different compression categories must be distinguished: lossless and lossy. Lossless compression is achieved if no distortion is introduced in the coded image. Applications requiring this type of compression include medical imaging and satellite photography. For applications such as video telephony or multimedia applications, some loss of information is usually tolerated in exchange for a high compression ratio. In this two-part paper, the major building blocks of image coding schemes are overviewed. Part I covers still image coding, and Part II covers motion picture sequences. In this first part, still image coding schemes have been classified into predictive, block transform, and multiresolution approaches. Predictive methods are suited to lossless and low-compression applications. Transform-based coding schemes achieve higher compression ratios for lossy compression but suffer from blocking artifacts at high-compression ratios. Multiresolution approaches are suited for lossy as well for lossless compression. At lossy high-compression ratios, the typical artifact visible in the reconstructed images is the ringing effect. New applications in a multimedia environment drove the need for new functionalities of the image coding schemes. For that purpose, second-generation coding techniques segment the image into semantically meaningful parts. Therefore, parts of these methods have been adapted to work for arbitrarily shaped regions. In order to add another functionality, such as progressive transmission of the information, specific quantization algorithms must be defined. A final step in the compression scheme is achieved by the codeword assignment. Finally, coding results are presented which compare stateof- the-art techniques for lossy and lossless compression. The different artifacts of each technique are highlighted and discussed. Also, the possibility of progressive transmission is illustrated
Sources of pro-cyclicality in east Asian financial systems
Procyclicality is a normal feature of economic systems, but financial sector
weaknesses can exacerbate it sufficiently to pose a threat to macroeconomic and financial
stability. These include shortcomings in bank risk management and governance, in
supervision and in terms of dependence on volatile sources of funds. The paper tests
econometrically for the importance of such features leading to pro-cyclicality in the financial
systems of 11 East Asian countries. This analysis makes it possible to identify specific policy
measures for East Asian countries that could limit the extent to which financial systems
exacerbate pro-cyclicality
Information sharing and credit : firm-level evidence from transition countries
We investigate whether information sharing among banks has affected credit market performance in the transition countries of Eastern Europe and the former Soviet Union, using a large sample of firm-level data. Our estimates show that information sharing is associated with improved availability and lower cost of credit to firms. This correlation is stronger for opaque firms than transparent ones and stronger in countries with weak legal environments than in those with strong legal environments. In cross-sectional estimates, we control for variation in country-level aggregate variables that may affect credit, by examining the differential impact of information sharing across firm types. In panel estimates, we also control for the presence of unobserved heterogeneity at the firm level, as well as for changes in macroeconomic variables and the legal environment
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