Search results for "linkage"
showing 10 items of 363 documents
An interest rates cluster analysis
2004
An empirical analysis of interest rates in money and capital markets is performed. We investigate a set of 34 different weekly interest rate time series during a time period of 16 years between 1982 and 1997. Our study is focused on the collective behavior of the stochastic fluctuations of these time-series which is investigated by using a clustering linkage procedure. Without any a priori assumption, we individuate a meaningful separation in 6 main clusters organized in a hierarchical structure.
Effects of record linkage errors on registry-based follow-up studies
1997
The importance of reliable record linkage for high quality-population-based disease registration is widely recognized. Systematic methodologic work is lacking, however, on the effects of record linkage errors on the use of disease registries for epidemiologic purposes. The present paper provides algebraic models describing the effects of record linkage errors on monitoring survival of registered patients, which is commonly performed by matching registry records against a database of death certificates, and on registry-based incidence follow-up of external cohorts. Homonym errors, that is, erroneous linkage of records that pertain to distinct individuals, lead to underestimation of survival …
A non-linear optimization procedure to estimate distances and instantaneous substitution rate matrices under the GTR model.
2006
Abstract Motivation: The general-time-reversible (GTR) model is one of the most popular models of nucleotide substitution because it constitutes a good trade-off between mathematical tractability and biological reality. However, when it is applied for inferring evolutionary distances and/or instantaneous rate matrices, the GTR model seems more prone to inapplicability than more restrictive time-reversible models. Although it has been previously noted that the causes for intractability are caused by the impossibility of computing the logarithm of a matrix characterised by negative eigenvalues, the issue has not been investigated further. Results: Here, we formally characterize the mathematic…
Do horizontal relationships matter to production and operations managers?
2014
This paper shifts the focus of production, operations and supply chain management business relationships from the vertical to the horizontal side and calls for more research on this issue. The main intent is to provide managerially oriented arguments regarding the linkages between the achievement of operations-related goals and decisions related to horizontal business relationships. Specifically, we address the following research question: Does a linkage exist between production and operations objectives and the decisions a company makes about horizontal agreements, particularly horizontal governance mode choice? To answer this research question, we develop literature-based hypotheses and c…
Transitioning towards a Sustainable Wellbeing Economy—Implications for Rural–Urban Relations
2021
This article focuses on the question of how a shift from a narrow economic perspective to a wider sustainable wellbeing focus in regional development strategies and actions might change rural–urban relations. A brief review of relevant research and discourses about economic development models provides the foundation for the analysis. The review leads to the development of an analytical framework that puts the notion of sustainable wellbeing at its center. The criteria included in the analytical framework are then used to assess the current situation, challenges and perceived ways forward based on data and analyses from 11 European regions. The focus of the analysis is on different exp…
Diagnosis and predictability of intraseasonal characteristics of wet and dry spells over equatorial east Africa
2010
Most of Eastern Africa has arid and semi-arid climate with high space-time variability in rainfall. The droughts are very common in this region, and often persist for several years, preceded or followed by extreme floods. Most of the livelihoods and socio-economic activities however remain rain-dependent leading to severe negative impacts during the periods of occurrence of climate extremes. It has been noted that one extreme event was capable of reversing national economic growth made over a period of several years. Thus no sustainable development can be attained in eastern Africa without effective mainstreaming of climate information in the development policies, plans and programmes. Many…
Linkage isomerism in the metal complex hexa(thiocyanato)rhenate(IV): Synthesis and crystal structure of (NBu4)2[Re(NCS)6] and [Zn(NO3)(Me2phen)2]2[Re…
2008
Abstract The linkage isomers [Re(NCS)6]2− and [Re(NCS)5(SCN)]2− are obtained by the reaction of [ReBr6]2− with NCS− in dimethylformamide. Some differences in the chemical behavior allowed their separation and structural characterization in the form of (NBu4)2[Re(NCS)6] (1) and [Zn(NO3)(Me2phen)2]2[Re(NCS)5(SCN)] (2), respectively (Bu = n-C4H9 and Me2phen = 2,9-dimethyl-1,10-phenanthroline).
Genetics of maximal walking speed and skeletal muscle characteristics in older women.
2008
AbstractThe aim of this study was to examine whether maximal walking speed, maximal isometric muscle strength, leg extensor power and lower leg muscle cross-sectional area (CSA) shared a genetic effect in common. In addition, we wanted to identify the chromosomal areas linked to maximal walking speed and these muscle characteristics and also investigate whether maximal walking speed and these three skeletal muscle characteristics are regulated by the same chromosomal areas. We studied 217 monozygotic (MZ) and dizygotic (DZ) female twin pairs aged 66 to 75 years in the Finnish Twin Study on Aging study. The DZ pairs (94) were genotyped for 397 microsatellite markers in 22 autosomes and X-chr…
PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity in Latvians, Lithuanians and Taiwanese
2014
PSMA6 (rs2277460, rs1048990), PSMC6 (rs2295826, rs2295827) and PSMA3 (rs2348071) genetic diversity was investigated in 1438 unrelated subjects from Latvia, Lithuania and Taiwan. In general, polymorphism of each individual locus showed tendencies similar to determined previously in HapMap populations. Main differences concern Taiwanese and include presence of rs2277460 rare allele A not found before in Asians and absence of rs2295827 rare alleles homozygotes TT observed in all other human populations. Observed patterns of SNPs and haplotype diversity were compatible with expectation of neutral model of evolution. Linkage disequilibrium between the rs2295826 and rs2295827 was detected to be c…
Vascular endothelial growth factor gene polymorphisms in ovarian cancer
2007
Abstract Background. Polymorphisms within the vascular endothelial growth factor (VEGF) gene, the most important regulator of angiogenesis and vascular permeability, were shown to be independently associated with an impaired prognosis in various malignancies. No data have been reported in ovarian cancer. Methods. In the present multi-center study, we examined three common polymorphisms within the VEGF gene ( VEGF +405G/C, VEGF −460C/T, and VEGF +936C/T) in 553 Caucasian patients with ovarian cancer using pyrosequencing. Results. The three investigated polymorphisms did not correlate with any of the investigated clinico-pathological parameters. In univariate and multivariate models, only FIG…