University of Copenhagen

About: University of Copenhagen is a education organization based out in Copenhagen, Denmark. It is known for research contribution in the topics: Population & Galaxy. The organization has 57645 authors who have published 149740 publications receiving 5903093 citations. The organization is also known as: Copenhagen University & Københavns Universitet.

Reduced Postprandial Concentrations of Intact Biologically Active Glucagon-Like Peptide 1 in Type 2 Diabetic Patients

Abstract: Incretin hormones importantly enhance postprandial insulin secretion but are rapidly degraded to inactive metabolites by ubiquitous dipeptidyl peptidase IV. The concentrations of the intact biologically active hormones remain largely unknown. Using newly developed assays for intact glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP), we measured plasma concentrations after a mixed breakfast meal (566 kcal) in 12 type 2 diabetic patients (age 57 years [range 49-67], BMI 31 kg/m2 [27-38], and HbA1c 9.2% [7.0-12.5]) and 12 matched healthy subjects. The patients had fasting hyperglycemia (10.7 mmol/l [8.0-14.8]) increasing to 14.6 mmol/l (11.5-21.5) 75 min after meal ingestion. Fasting levels of insulin and C-peptide were similar to those of the healthy subjects, but the postprandial responses were reduced and delayed. Fasting levels and meal responses were similar between patients and healthy subjects for total GIP (intact + metabolite) as well as intact GIP, except for a small decrease in the patients at 120 min; integrated areas for intact hormone (area under the curve [AUC]INT) averaged 52 +/- 4% (for patients) versus 56 +/- 3% (for control subjects) of total hormone AUC (AUC(TOT)). AUC(INT) for GLP-1 averaged 48 +/- 2% (for patients) versus 51 +/- 5% (for control subjects) of AUC(TOT). AUC(TOT) for GLP-1 as well as AUC(INT) tended to be reduced in the patients (P = 0.2 and 0.07, respectively); but the profile of the intact GLP-1 response was characterized by a small early rise (30-45 min) and a significantly reduced late phase (75-150 min) (P < 0.02). The measurement of intact incretin hormones revealed that total as well as intact GIP responses were minimally decreased in patients with type 2 diabetes, whereas the late intact GLP-1 response was strongly reduced, supporting the hypothesis that an impaired function of GLP-1 as a transmitter in the enteroinsular axis contributes to the inappropriate insulin secretion in type 2 diabetes.

A plea for DNA taxonomy

Abstract: Taxonomy underpins all biological research, with implications for many basic scientific and applied fields. Insights into the stability or change of animal and plant guilds require species identification on a broad scale and biodiversity questions have become a major public issue. But this comes at a time when taxonomy is facing a crisis, because ever fewer specialists are available. Here, we explore the possibility of using DNA-based methodology to overcome these problems. The utility of DNA sequences for taxonomic purposes is well established. However, all current taxonomic approaches intend to use DNA, at best, as an auxiliary criterion for identifying a species or a taxon, but have not given it a central role. We propose a scheme in which DNA would be the scaffold of a taxonomic reference system, whilst maintaining the importance of the morphological information associated with whole specimens.

The WiggleZ Dark Energy Survey: mapping the distance-redshift relation with baryon acoustic oscillations

Abstract: We present measurements of the baryon acoustic peak at redshifts z = 0.44, 0.6 and 0.73 in the galaxy correlation function of the final dataset of the WiggleZ Dark Energy Survey. We combine our correlation function with lower-redshift measurements from the 6-degree Field Galaxy Survey and Sloan Digital Sky Survey, producing a stacked survey correlation function in which the statistical significance of the detection of the baryon acoustic peak is 4.9-σ relative to a zero-baryon model with no peak. We fit cosmological models to this combined baryon acoustic oscillation (BAO) dataset comprising six distance-redshift data points, and compare the results to similar fits to the latest compilation of supernovae (SNe) and Cosmic Microwave Background (CMB) data. The BAO and SNe datasets produce consistent measurements of the equation-ofstate w of dark energy, when separately combined with the CMB, providing a powerful check for systematic errors in either of these distance probes. Combining all datasets we determine w = 1.03 ± 0.08 for a flat Universe, consistent with a cosmological constant model. Assuming dark energy is a cosmological constant and varying the spatial curvature, we find k = 0.004± 0.006.

Gut microbiome and serum metabolome alterations in obesity and after weight-loss intervention

Abstract: Emerging evidence has linked the gut microbiome to human obesity. We performed a metagenome-wide association study and serum metabolomics profiling in a cohort of lean and obese, young, Chinese individuals. We identified obesity-associated gut microbial species linked to changes in circulating metabolites. The abundance of Bacteroides thetaiotaomicron, a glutamate-fermenting commensal, was markedly decreased in obese individuals and was inversely correlated with serum glutamate concentration. Consistently, gavage with B. thetaiotaomicron reduced plasma glutamate concentration and alleviated diet-induced body-weight gain and adiposity in mice. Furthermore, weight-loss intervention by bariatric surgery partially reversed obesity-associated microbial and metabolic alterations in obese individuals, including the decreased abundance of B. thetaiotaomicron and the elevated serum glutamate concentration. Our findings identify previously unknown links between intestinal microbiota alterations, circulating amino acids and obesity, suggesting that it may be possible to intervene in obesity by targeting the gut microbiota.

Unwilling or Unable to Cheat? Evidence From a Tax Audit Experiment in Denmark

Abstract: This paper analyzes a tax enforcement field experiment in Denmark. In the base year, a stratified and representative sample of over 40,000 individual income tax filers was selected for the experiment. Half of the tax filers were randomly selected to be thoroughly audited, while the rest were deliberately not audited. The following year, threat-of-audit letters were randomly assigned and sent to tax filers in both groups. We present three main empirical findings. First, using baseline audit data, we find that the tax evasion rate is close to zero for income subject to third-party reporting, but substantial for self-reported income. Since most income is subject to third-party reporting, the overall evasion rate is modest. Second, using quasi-experimental variation created by large kinks in the income tax schedule, we find that marginal tax rates have a positive impact on tax evasion for self-reported income, but that this effect is small in comparison to legal avoidance and behavioral responses. Third, using the randomization of enforcement, we find that prior audits and threat-of-audit letters have significant effects on self-reported income, but no effect on third-party reported income. All these empirical results can be explained by extending the standard model of (rational) tax evasion to allow for the key distinction between self-reported and third-party reported income.