Genetic Diversity and Population Parameters of Sea Otters, Enhydra lutris, before Fur Trade Extirpation from 1741–1911

All existing sea otter, Enhydra lutris, populations have suffered at least one historic population bottleneck stemming from the fur trade extirpations of the eighteenth and nineteenth centuries. We examined genetic variation, gene flow, and population structure at five microsatellite loci in samples from five pre-fur trade populations throughout the sea otter's historical range: California, Oregon, Washington, Alaska, and Russia. We then compared those values to genetic diversity and population structure found within five modern sea otter populations throughout their current range: California, Prince William Sound, Amchitka Island, Southeast Alaska and Washington. We found twice the genetic diversity in the pre-fur trade populations when compared to modern sea otters, a level of diversity that was similar to levels that are found in other mammal populations that have not experienced population bottlenecks. Even with the significant loss in genetic diversity modern sea otters have retained historical structure. There was greater gene flow before extirpation than that found among modern sea otter populations but the difference was not statistically significant. The most dramatic effect of pre fur trade population extirpation was the loss of genetic diversity. For long term conservation of these populations increasing gene flow and the maintenance of remnant genetic diversity should be encouraged

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)

Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.

Telomere length is a risk factor in disease and the dynamics of telomere length are crucial to our understanding of cell replication and vitality. The proliferation of whole genome sequencing represents an unprecedented opportunity to glean new insights into telomere biology on a previously unimaginable scale. To this end, a number of approaches for estimating telomere length from whole-genome sequencing data have been proposed. Here we present Telomerecat, a novel approach to the estimation of telomere length. Previous methods have been dependent on the number of telomeres present in a cell being known, which may be problematic when analysing aneuploid cancer data and non-human samples. Telomerecat is designed to be agnostic to the number of telomeres present, making it suited for the purpose of estimating telomere length in cancer studies. Telomerecat also accounts for interstitial telomeric reads and presents a novel approach to dealing with sequencing errors. We show that Telomerecat performs well at telomere length estimation when compared to leading experimental and computational methods. Furthermore, we show that it detects expected patterns in longitudinal data, repeated measurements, and cross-species comparisons. We also apply the method to a cancer cell data, uncovering an interesting relationship with the underlying telomerase genotype

Predicting age from cortical structure across the lifespan

Despite inter-individual differences in cortical structure, cross-sectional and longitudinal studies have demonstrated a large degree of population-level consistency in age-related differences in brain morphology. The present study assessed how accurately an individual’s age could be predicted by estimates of cortical morphology, comparing a variety of structural measures, including thickness, gyrification, and fractal dimensionality. Structural measures were calculated across up to seven different parcellation approaches, ranging from 1 region to 1000 regions. The age-prediction framework was trained using morphological measures obtained from T1-weighted MRI volumes collected from multiple sites, yielding a training dataset of 1056 healthy adults, aged 18-97. Age predictions were calculated using a machine-learning approach that incorporated non-linear differences over the lifespan. In two independent, held-out test samples, age predictions had a median error of 6-7 years. Age predictions were best when using a combination of cortical metrics, both thickness and fractal dimensionality. Overall, the results reveal that age-related differences in brain structure are systematic enough to enable reliable age prediction based on metrics of cortical morphology

GWAS meta-analysis of intrahepatic cholestasis of pregnancy implicates multiple hepatic genes and regulatory elements

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder affecting 0.5–2% of pregnancies. The majority of cases present in the third trimester with pruritus, elevated serum bile acids and abnormal serum liver tests. ICP is associated with an increased risk of adverse outcomes, including spontaneous preterm birth and stillbirth. Whilst rare mutations affecting hepatobiliary transporters contribute to the aetiology of ICP, the role of common genetic variation in ICP has not been systematically characterised to date. Here, we perform genome-wide association studies (GWAS) and meta-analyses for ICP across three studies including 1138 cases and 153,642 controls. Eleven loci achieve genome-wide significance and have been further investigated and fine-mapped using functional genomics approaches. Our results pinpoint common sequence variation in liver-enriched genes and liver-specific cis-regulatory elements as contributing mechanisms to ICP susceptibility

Publisher Correction: Telomerecat: A ploidy-agnostic method for estimating telomere length from whole genome sequencing data.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper

Impact of Internet Self-Efficacy on e-Service Brands

As the Internet expands to include individual applications such as banking, shopping, information gathering, and so on, brand managers and marketers have turned to the Internet to utilize it as an effective branding vehicle. Consequently, understanding how the Internet could be used effectively in e-branding becomes imperative. One barrier to a successful utilization of the Internet as a branding tool is the rate at which individuals adopt and use the various e-services made available to them. As will be discussed, adoption depends, in part, on the users’ level of Internet self-efficacy. This chapter illustrates a conceptual framework for understanding Internet self-efficacy and presents findings from an exploratory experiment designed to investigate the link between self-efficacy, attitudes toward e-services and individuals’ likelihood of using such e-services. Results are presented and managerial implications for e-service providers are drawn

Third-Person Effect and Social Networking: Implications for Online Marketing and Word-of-Mouth Communication.

Few studies have explored the direct influence of social networking websites (SNWs), and to the best of our knowledge, none have examined the indirect influence of SNWs on users and how that indirect influence leads to word-of-mouth related behaviors in SNWs. This study employs the theoretical framework of the third-person effect theory, which is grounded in psychology, to examine the indirect influence of SNWs and how that indirect influence may potentially contribute to marketing research and practice. Davison’s (1983) third-person effect (TPE) theory proposes that individuals tend to expect mass media to have a greater effect on others than on themselves. After the analysis of survey data, the current research first explores whether a third-person effect exists in the SNW context and if it does, how it differs from that in traditional media context. Based on theory and numerous empirical findings, the current research also investigates how the thirdperson effect varies with different referent “others”. Finally, based on the theoretical propositions of previous studies, this study links third-person effect to behavioral consequences related to word-of-mouth communication via SNWs. The results support all hypotheses. This work contributes to consumer psychology and word-of-mouth communication research, and generates implications for marketers targeting young consumers and/or those interested in stimulating word-of-mouth communication in the SNW context. Limitations are also addressed

Effects of 3-D Visualization on Persuasion in Online Shopping Sites: A Moderating Role of Product Knowledge

The use of a three-dimensional (3-D) visualization in commercial Websites has been growing. In order to better understand the influences of this technology on marketing, a laboratory experiment (n=104) was conducted to examine the effects of visualization type (3-D vs. 2-D) and prior product knowledge (low vs. high) on persuasion. The results indicate that 3-D visualization positively influences attitude, and this relationship was found to be greater for novices than experts. Furthermore, a consumer’s sense of presence was found to mediate the effects of product visualization type on persuasion as previously postulated. These findings and future implications for developing effecting online marketing strategies are discussed