Search results for "Heterogeneity."

Genetic relationship between clinical and environmental Vibrio cholerae isolates in Tanzania: A comparison using repetitive extragenic palindromic (R…

2015

The bacterium causing cholera, Vibrio cholerae, is a marine organism and coastal waters are important reservoirs of the organism. There are more than 200 serogroups of V. cholerae, of which serogroups O1 and O139 are known to be the causative agent of the cholera. The main virulent factor in V. cholerae is cholera toxin gene (ctx) that is found from the epidemic O1 and O139 strains, but may also be found in some strains other than O1 and O139 (non-O1 and non-O139). In this study, 48 V. cholerae strains isolated from three estuaries of Tanzania and 20 stool isolates were characterized in terms of their serogroups and possession of ctx gene and then compared using two PCR based fingerprinting…

How news affect the trading behavior of different categories of investors in a financial market

2015

We investigate the trading behavior of a large set of single investors trading the highly liquid Nokia stock over the period 2003-2008 with the aim of determining the relative role of endogenous and exogenous factors that may affect their behavior. As endogenous factors we consider returns and volatility, whereas the exogenous factors we use are the total daily number of news and a semantic variable based on a sentiment analysis of news. Linear regression and partial correlation analysis of data show that different categories of investors are differently correlated to these factors. Governmental and non profit organizations are weakly sensitive to news and returns or volatility, and, typica…

Variants of human CLDN9 cause mild to profound hearing loss

2021

Hereditary deafness is clinically and genetically heterogeneous. We investigated deafness segregating as a recessive trait in two families. Audiological examinations revealed an asymmetric mild to profound hearing loss with childhood or adolescent onset. Exome sequencing of probands identified a homozygous c.475G>A;p.(Glu159Lys) variant of CLDN9 (NM_020982.4) in one family and a homozygous c.370_372dupATC;p.(Ile124dup) CLDN9 variant in an affected individual of a second family. Claudin 9 (CLDN9) is an integral membrane protein and constituent of epithelial bicellular tight junctions that form semi-permeable, paracellular barriers between inner ear perilymphatic and endolymphatic compartment…

Is personality related to permanent earnings? Evidence using a twin design

2018

Using twin survey combined with register-based panel data on labor market outcomes, the authors examine the association between personality characteristics and long-term earnings among prime working-age individuals. The long-term earnings were measured over the 1990–2008 period. The sample contains 4,642 twin pairs, of which 53% are females. In contrast to previous studies, this paper uses the within-twin dimension of the data to control for shared family background and confounding genetic factors. The results suggest that unobserved genetic differences may introduce omitted variable bias in standard ordinary least square results. After controlling for shared environment and genetic backgro…

Assessing the conservation priority of freshwater lake sites based on taxonomic, functional and environmental uniqueness

2022

Aim We propose a novel approach that considers taxonomic uniqueness, functional uniqueness and environmental uniqueness and show how it can be used in guiding conservation planning. We illustrate the approach using data for lake biota and environment. Location Lake Puruvesi, Finland. Methods We sampled macrophytes and macroinvertebrates from the same 18 littoral sites. By adapting the original “ecological uniqueness” approach, we used distance-based methods to calculate measures of taxonomic (LCBD–t), functional (LCBD–f) and environmental (LCEH) uniqueness for each site. We also considered the numbers and locations of the sites needed to protect up to 70% of total variation in taxonomic, fu…

Economics of wage differentials and public sector labour markets

2013

The importance of phytoplankton production for carbon budgets in a semiarid floodplain wetland

2011

Phytoplankton production (PP) in wetlands is not measured as often as that of macrophytes. A three year-study during a period of sustained high flooding was undertaken in a central Spanish floodplain wetland (Las Tablas de Daimiel National Park) to determine net PP, its spatial heterogeneity and controlling factors, and compare it with primary production in macrophyte communities. This enabled us to estimate carbon budgets for each community. All PP variables showed high spatial and temporal variability among sites, resulting in low coherence even when flooding connected all sites. Net PP corresponded to 25- 36% of submerged plant production and 3-10% of helophyte production. Net PP was con…

Spatial econometrics (1, Spatial autocorrelation)

2000

Spatial econometric methods aim at taking into account the two special characteristics of spatial data: spatial autocorrelation, which is the lack of independence between geographical observations, and spatial heterogeneity, which is related to the differentiation of variables and behaviors in space. These techniques have been mostly developed the last ten years and are more often applied in empirical studies with geographical data.The aim of this article is to present the way spatial autocorrelation and spatial heterogeneity can be incorporated in regression relationships and to present the estimation and inference procedures adapted to the models incorporating these two effects. This arti…