114 research outputs found
Finite term relations for the exponential orthogonal polynomials
The exponential orthogonal polynomials encode via the theory of hyponormal
operators a shade function supported by a bounded planar shape. We prove
under natural regularity assumptions that these complex polynomials satisfy a
three term relation if and only if the underlying shape is an ellipse carrying
uniform black on white. More generally, we show that a finite term relation
among these orthogonal polynomials holds if and only if the first row in the
associated Hessenberg matrix has finite support. This rigidity phenomenon is in
sharp contrast with the theory of classical complex orthogonal polynomials. On
function theory side, we offer an effective way based on the Cauchy transforms
of , to decide whether a
-term relation among the exponential orthogonal polynomials exists; in
that case we indicate how the shade function can be reconstructed from a
resulting polynomial of degree and the Cauchy transform of . A
discussion of the relevance of the main concepts in Hele-Shaw dynamics
completes the article.Comment: 33 page
Szego coordinates, quadrature domains, and double quadrature domains
We define Szego coordinates on a finitely connected smoothly bounded planar
domain which effect a holomorphic change of coordinates on the domain that can
be as close to the identity as desired and which convert the domain to a
quadrature domain with respect to boundary arc length. When these Szego
coordinates coincide with Bergman coordinates, the result is a double
quadrature domain with respect to both area and arc length. We enumerate a host
of interesting and useful properties that such double quadrature domains
possess, and we show that such domains are in fact dense in the realm of
bounded finitely connected domains with smooth boundaries.Comment: 19 page
A Tale of Two Countries: Poverty among Immigrants in Denmark and Sweden since 1984
poverty, immigrants, panel data
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Use of GenericsâA Critical Cost Containment Measure for All Healthcare Professionals in Europe?
Pharmaceutical expenditures in ambulatory care rose rapidly in Europe in the 1990s and early 2000s. This was typically faster than other components of healthcare spending, leading to reforms to moderate future growth. A number of these centered on generic medicines with measures to lower reimbursed prices as well as enhance their prescribing and dispensing. The principal objective of this paper is to review additional measures that some European countries can adopt to further reduce reimbursed prices for generics. Secondly, potential approaches to address concerns with generics when they arise to maximize savings. Measures to enhance the prescribing of generics will also briefly be discussed. A narrative review of the extensive number of publications and associated references from the co-authors was conducted supplemented with known internal or web-based articles. In addition, health authority and health insurance databases, principally from 2001 to 2007, were analyzed to assess the impact of the various measures on price reductions for generic omeprazole and generic simvastatin vs. pre-patent loss prices, as well as overall efficiency in Proton Pump Inhibitor (PPI) and statin prescribing. The various initiatives generally resulted in considerable lowering of the prices of generics as well as specifically for generic omeprazole and generic simvastatin vs. pre-patent loss prices. At one stage in the UK, generic simvastatin was just 2% of the originator price. These measures also led to increased efficiency for PPI and statin prescribing with reimbursed expenditure for the PPIs and statins either falling or increasing at appreciably lower rates than increases in utilization. A number of strategies have also been introduced to address patient and physician concerns with generics to maximize savings. In conclusion, whilst recent reforms have been successful, European countries must continue learning from each other to fund increased volumes and new innovative drugs as resource pressures grow. Policies regarding generics and their subsequent impact on reimbursement and utilization of single sourced products will continue to play a key role to release valuable resources. However, there must continue to be strategies to address concerns with generics when they exist
Salivary Matrix Metalloproteinase-8 and-9 and Myeloperoxidase in Relation to Coronary Heart and Periodontal Diseases : A Subgroup Report from the PAROKRANK Study (Periodontitis and Its Relation to Coronary Artery Disease)
Background and Objective Matrix metalloproteinase (MMP) -8, -9 and myeloperoxidase (MPO) are inflammatory mediators. The potential associations between MMP-8, -9, MPO and their abilities to reflect cardiovascular risk remains to be evaluated in saliva. The objective of this study was to investigate the levels and associations of salivary MMP-8, -9, MPO and tissue inhibitors of metalloproteinase (TIMP)-1 in myocardial infarction (MI) patients and controls with or without periodontitis. Materials and Methods 200 patients with a first MI admitted to coronary care units in Sweden from May 2010 to December 2011 and 200 controls matched for age, gender, residential area and without previous MI were included. Dental examination and saliva sample collection was performed 6-10 weeks after the MI in patients and at baseline in controls. The biomarkers MMP -8, -9, MPO and TIMP-1 were analyzed by time-resolved immunofluorescence assay (IFMA), Western blot and Enzyme-Linked ImmunoSorbent Assay (ELISA). Results After compensation for gingivitis, gingival pockets and smoking, the mean salivary levels of MMP-8 (543 vs 440 ng/mL, p = 0.003) and MPO (1899 vs 1637 ng/mL, p = 0.02) were higher in non-MI subjects compared to MI patients. MMP-8, -9 and MPO correlated positively with clinical signs of gingival/periodontal inflammation while TIMP-1 correlated mainly negatively with these signs. The levels of latent and active forms of MMP-8 did not differ between the MI and non-MI groups. Additionally, MMP-8, MPO levels and MMP-8/TIMP-1 ratio were significantly higher in men compared to women with MI. Conclusions This study shows that salivary levels of the analyzed biomarkers are associated with periodontal status. However, these biomarkers could not differentiate between patients with or without a MI. These findings illustrate the importance to consider the influence of oral conditions when analyzing levels of inflammatory salivary biomarkers.Peer reviewe
Policies to Enhance Prescribing Efficiency in Europe: Findings and Future Implications
Introduction: European countries need to learn from each other to address unsustainable increases in pharmaceutical expenditures. Objective: To assess the influence of the many supply and demand-side initiatives introduced across Europe to enhance prescribing efficiency in ambulatory care. As a result provide future guidance to countries. Methods: Cross national retrospective observational study of utilization (DDDs â defined daily doses) and expenditure (Euros and local currency) of proton pump inhibitors (PPIs) and statins among 19 European countries and regions principally from 2001 to 2007. Demand-side measures categorized under the â4Esâ â education engineering, economics, and enforcement. Results: Instigating supply side initiatives to lower the price of generics combined with demand-side measures to enhance their prescribing is important to maximize prescribing efficiency. Just addressing one component will limit potential efficiency gains. The influence of demand-side reforms appears additive, with multiple initiatives typically having a greater influence on increasing prescribing efficiency than single measures apart from potentially âenforcement.â There are also appreciable differences in expenditure (âŹ/1000 inhabitants/year) between countries. Countries that have not introduced multiple demand side measures to counteract commercial pressures to enhance the prescribing of generics have seen considerably higher expenditures than those that have instigated a range of measures. Conclusions: There are considerable opportunities for European countries to enhance their prescribing efficiency, with countries already learning from each other. The 4E methodology allows European countries to concisely capture the range of current demand-side measures and plan for the future knowing that initiatives can be additive to further enhance their prescribing efficiency
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