Food distribution influences social organization and population growth in a small rodent

This is the postprint version of the article. The published article can be located at the publisher's websiteIn polygynous mammals, the spatial clumping and predictability of food should influence spacing behavior of females whose reproductive success depends to a great extent on food availability, which would in turn affect male spacing behavior. Changes in the social and mating systems can then influence individual fitness and population dynamics. To test these hypotheses, we manipulated food distribution and predictability in enclosed populations of bank voles (Myodes glareolus) and monitored spacing behavior, survival, and reproduction of adult females and males over 3 months. Food was either spread out (dispersed treatment), spatially clumped and highly predictable (clumped treatment) or spatially clumped but less predictable (variable treatment). We found that females in the clumped treatment were more aggregated and had more overlapping home ranges compared with females in the dispersed and variable treatments. Male spacing behavior followed the same patterns. Despite different social organizations between treatments, no differences in home range size and mating systems were found in females and males. In addition, we found that females in the clumped food treatment had a higher probability of successfully producing weaned offspring, likely due to lower infanticide rates. This led to higher population growth compared with the other 2 treatments. These results suggest a tight relationship between the spatiotemporal distribution of food, social organization, and population dynamics.2014-04-3

Food distribution influences social organization and population growth in a small rodent

This is the postprint version of the article. The published article can be located at the publisher's websiteIn polygynous mammals, the spatial clumping and predictability of food should influence spacing behavior of females whose reproductive success depends to a great extent on food availability, which would in turn affect male spacing behavior. Changes in the social and mating systems can then influence individual fitness and population dynamics. To test these hypotheses, we manipulated food distribution and predictability in enclosed populations of bank voles (Myodes glareolus) and monitored spacing behavior, survival, and reproduction of adult females and males over 3 months. Food was either spread out (dispersed treatment), spatially clumped and highly predictable (clumped treatment) or spatially clumped but less predictable (variable treatment). We found that females in the clumped treatment were more aggregated and had more overlapping home ranges compared with females in the dispersed and variable treatments. Male spacing behavior followed the same patterns. Despite different social organizations between treatments, no differences in home range size and mating systems were found in females and males. In addition, we found that females in the clumped food treatment had a higher probability of successfully producing weaned offspring, likely due to lower infanticide rates. This led to higher population growth compared with the other 2 treatments. These results suggest a tight relationship between the spatiotemporal distribution of food, social organization, and population dynamics.2014-04-3

The insulin polymorphism -23Hph increases the risk for type 1 diabetes mellitus in the Romanian population

The insulin -23Hph and IGF2 Apa polymorphisms were genotyped in Romanian patients with T1DM (n = 204), T2DM (n = 215) or obesity (n = 200) and normoponderal healthy subjects (n = 750). The genotypes of both polymorphisms were distributed in concordance with Hardy-Weinberg equilibrium in all groups. The -23Hph AA genotype increased the risk for T1DM (OR: 3.22, 95%CI: 2.09-4.98, p < 0,0001), especially in patients without macroalbuminuria (OR: 4.32, 95%CI: 2.54-7.45, p < 0,0001). No other significant association between the alleles or genotypes of insulin -23Hph and IGF2 Apa and diabetes or obesity was identified

Neighborhood level risk factors for type 1 diabetes in youth: the SEARCH case-control study

<p>Abstract</p> <p>Background</p> <p>European ecologic studies suggest higher socioeconomic status is associated with higher incidence of type 1 diabetes. Using data from a case-control study of diabetes among racially/ethnically diverse youth in the United States (U.S.), we aimed to evaluate the independent impact of neighborhood characteristics on type 1 diabetes risk. Data were available for 507 youth with type 1 diabetes and 208 healthy controls aged 10-22 years recruited in South Carolina and Colorado in 2003-2006. Home addresses were used to identify Census tracts of residence. Neighborhood-level variables were obtained from 2000 U.S. Census. Multivariate generalized linear mixed models were applied.</p> <p>Results</p> <p>Controlling for individual risk factors (age, gender, race/ethnicity, infant feeding, birth weight, maternal age, number of household residents, parental education, income, state), higher neighborhood household income (p = 0.005), proportion of population in managerial jobs (p = 0.02), with at least high school education (p = 0.005), working outside the county (p = 0.04) and vehicle ownership (p = 0.03) were each independently associated with increased odds of type 1 diabetes. Conversely, higher percent minority population (p = 0.0003), income from social security (p = 0.002), proportion of crowded households (0.0497) and poverty (p = 0.008) were associated with a decreased odds.</p> <p>Conclusions</p> <p>Our study suggests that neighborhood characteristics related to greater affluence, occupation, and education are associated with higher type 1 diabetes risk. Further research is needed to understand mechanisms underlying the influence of neighborhood context.</p

Celiac disease: how complicated can it get?

In the small intestine of celiac disease patients, dietary wheat gluten and similar proteins in barley and rye trigger an inflammatory response. While strict adherence to a gluten-free diet induces full recovery in most patients, a small percentage of patients fail to recover. In a subset of these refractory celiac disease patients, an (aberrant) oligoclonal intraepithelial lymphocyte population develops into overt lymphoma. Celiac disease is strongly associated with HLA-DQ2 and/or HLA-DQ8, as both genotypes predispose for disease development. This association can be explained by the fact that gluten peptides can be presented in HLA-DQ2 and HLA-DQ8 molecules on antigen presenting cells. Gluten-specific CD4+ T cells in the lamina propria respond to these peptides, and this likely enhances cytotoxicity of intraepithelial lymphocytes against the intestinal epithelium. We propose a threshold model for the development of celiac disease, in which the efficiency of gluten presentation to CD4+ T cells determines the likelihood of developing celiac disease and its complications. Key factors that influence the efficiency of gluten presentation include: (1) the level of gluten intake, (2) the enzyme tissue transglutaminase 2 which modifies gluten into high affinity binding peptides for HLA-DQ2 and HLA-DQ8, (3) the HLA-DQ type, as HLA-DQ2 binds a wider range of gluten peptides than HLA-DQ8, (4) the gene dose of HLA-DQ2 and HLA-DQ8, and finally,(5) additional genetic polymorphisms that may influence T cell reactivity. This threshold model might also help to understand the development of refractory celiac disease and lymphoma

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe