Dispersion relations for η′→ηππ\eta'\to\eta\pi\pi

We present a dispersive analysis of the decay amplitude for $\eta'\to\eta\pi\pi$ that is based on the fundamental principles of analyticity and unitarity. In this framework, final-state interactions are fully taken into account. Our dispersive representation relies only on input for the $\pi\pi$ and $\pi\eta$ scattering phase shifts. Isospin symmetry allows us to describe both the charged and neutral decay channel in terms of the same function. The dispersion relation contains subtraction constants that cannot be fixed by unitarity. We determine these parameters by a fit to Dalitz-plot data from the VES and BES-III experiments. We study the prediction of a low-energy theorem and compare the dispersive fit to variants of chiral perturbation theory.Comment: 22 pages, 10 figures; v2: added footnote, version published in EPJ

Telomeric RNAs as a novel player in telomeric integrity

Telomeres protect linear chromosome ends from being recognized and processed as double-strand breaks by DNA repair activities. This protective function of telomeres is essential for chromosome stability. Until recently, telomeres have been considered to be transcriptionally silent. This notion was overturned in a series of recent papers that describe the existence of telomeric repeat-containing RNAs (TERRAs) in vertebrates and yeast. Here, we summarize recent developments in this field of telomere research, in particular the possible mechanisms that control TERRA expression

Effects of long-term soluble vs. insoluble dietary fiber intake on high-fat diet-induced obesity in C57BL/6J mice

Although most of the proposed beneficial effects of fiber consumption have been attributed to viscous and gel-forming properties of soluble fiber, it is mainly insoluble cereal fiber and whole grains that are strongly associated with reduced diabetes risk in prospective cohort studies, indicating that other unknown mechanisms are likely to be involved. We performed a long-term study investigating potential protective effects of adding soluble guar fiber (10% w/w) vs. insoluble cereal fiber (10% w/w) to an isoenergetic and macronutrient matched high-fat diet in obesity-prone C57BL/6J mice. After 45 weeks, mice fed soluble vs. insoluble fiber showed both significantly increased body weight (41.8±3.0 vs. 33.6±1.5 g, P=.03) and elevated markers of insulin resistance. In mice fed soluble fiber, energy loss via the feces was significantly lower and colonic fermentation with production of short chain fatty acids (SCFA) was markedly increased. Gene expression analysis in white adipose tissue showed significantly increased levels of the fatty acid target G-protein coupled receptor-40 in soluble fiber-fed mice. Liver gene expression in the insoluble fiber group showed a pattern consistent with increased fatty acid oxidation. The present results show that soluble vs insoluble dietary fiber added to a high-fat, Western-style diet differently affected body weight and estimates of insulin sensitivity in obesity-prone mice. Soluble fiber intake with increased SCFA production significantly contributed to digested energy, thereby potentially outweighing the well known short-term beneficial effects of soluble fiber consumption

Qualitätskriterien für Bilderbuch-Apps

Diese Bachelorarbeit befasst sich mit der Aufstellung Qualitätskriterien für Bilderbuch-Apps als mögliche Richtlinie für Bibliotheken und Multiplikatoren in der Vermittlungsarbeit. Zunächst werden die Qualitätskriterien des klassischen Bilderbuchs betrachtet. Im Anschluss daran werden diese auf Bilderbuch-Apps übertragen und die App-spezifischen Qualitätskriterien ermittelt, wobei die Marktsichtung mithilfe eines iPad 2 erfolgte. Die Qualität von Bilderbüchern wird größtenteils durch die Umsetzung der Bild-Text-Interdependenzen beeinflusst. Bei Bilderbuch-Apps kommt zur Bild-Text-Interdependenz die gelungene Einbindung der multimedialen Interaktionsmöglichkeiten als Einflussfaktor hinzu. Das bedeutet v.a., dass die Interaktivität auf die Geschichte des Bilderbuchs ausgerichtet sein sollte, um die Aufmerksamkeit des Kindes auf diese zu fokussieren. Wird die Qualität bei klassischen Bilderbüchern von der Abstimmung von Form, Farbe und Komposition beeinflusst, sind es bei Bilderbuch-Apps Layout, Design und Animation, die aufeinander abgestimmt werden müssen, um eine überzeugende Bilderbuch-App zu entwickeln. Abschließend werden die Qualitätskriterien zusammengefasst und ein Ausblick auf die Zukunft von Bilderbuch-Apps gegeben

Circulating vaspin is unrelated to insulin sensitivity in a cohort of nondiabetic humans

Objective: To study the association of vaspin with glucose metabolism. Design: Cross-sectional and intervention study. Subjects and methods: The association of serum vaspin with metabolic and anthropometric characteristics was investigated in 108 volunteers. Euglycemic–hyperinsulinemic clamps (EHC) were performed in 83 of the participants. Changes of circulating vaspin levels were additionally studied in a crossover study using 300 min EHC with lipid versus saline infusion (n=10). Results: Neither glucose tolerance status nor insulin sensitivity, both as measured using EHCs and using homeostasis model assessment for insulin resistance (HOMA-IR), was significantly associated with serum vaspin in the cross-sectional study. Furthermore, there was no effect of short-term lipid-induced insulin resistance due to a 300 min intravenous lipid challenge on circulating vaspin. However, circulating vaspin levels were significantly elevated in women using oral contraceptives (OC), both compared to women without OC intake (1.17±0.26 vs 0.52±0.09 ng/ml, P=0.02) and males (1.17±0.26 vs 0.29±0.04 ng/ml, P=0.01). After exclusion of OC using females and stratification according to body mass index (BMI), a significant sexual dimorphism in subjects with a BMI <25 kg/m2 was observed (males 0.21±0.04 ng/ml versus females 0.70±0.16 ng/ml, P=0.009). Conclusion: Our results support the existence of a sexual dimorphism regarding circulating vaspin. The lack of an association of serum vaspin with HOMA-IR and M value indicates, however, no major role for vaspin concerning insulin sensitivity in nondiabetic humans

Physiology of solvent tolerance in Pseudomonas putida S12

Hydrophobic organic solvents, like toluene, are toxic for living organisms. This toxicity is an important drawback in the environmental biotechnology as well as in the application of solvents in the production of fine chemicals by whole-cell biotransformations. The effects of organic solvents on micro-organisms have been studied extensively. It was shown that the toxicity of hydrophobic organic solvents is mainly caused by the ability of such solvents to intercalate and accumulate in biological membranes.In the last decade, however, several strains that can survive the presence of toxic organic solvents have been isolated. One of the solvent-tolerant strains is Pseudomonas putida S12, studied in this thesis. This strain can grow in the presence of a second phase of organic solvents that have a log P O/W (logarithm of the partition coefficient between octanol and water) value equal to or higher than 2.3. P. putida S12 is able to survive the presence of solvents because of different adaptation mechanisms. This strain can suppress the effect of organic solvents on the membranes by a cis to trans isomerization of the unsaturated fatty acids of the membrane.A further adaptation mechanism is presented in this thesis. It is shown that cells adapted to toluene posses an active export system for toluene. Therefore, P. putida S12 compensates not only the toxic effects of organic solvents on the membrane, but decrease also actively the amount of the toxic solvent in the cell. In the presence of the efflux system the concentration of a solvent in the bacterial membrane can be below the theoretical equilibrium. This active efflux system depends on the proton motive force.Since we reported the presence of an active export system for solvents, it has been suggested repeatedly, that this system is connected with the well-described efflux systems for antibiotics. Indeed, the adaptation of P. putida S12 to toluene enhances the resistance of this strain to various chemically and structurally unrelated antibiotics, with different targets in the cell.However, we could demonstrate that efflux system for toluene in P. putida S12 does not export antibiotics. This efflux system is specific for solvents like toluene and p -xylene. Therefore, the adaptation to an organic solvent must activate other mechanisms responsible for the resistance towards these antibiotics. Likely, this is connected to a general stress response. This general stress response may also cause the decrease of the cell-envelope permeability discussed in the thesis.The broad effect solvents have even on the solvent-tolerant strain P. putida S12 are demonstrated. The presence of toluene reduces the maximum growth yield and increases the maintenance requirement. Interestingly, other solvents had a similar effect as toluene as long as they reached the same concentration in the bacterial membrane. Not the chemical structure but the amount of solvent accumulated in the bacterial membrane determines the effect of a solvent on the cells. Therefore, results obtained with toluene can be extrapolated to other solvents as well.</p

Metabolic effects of diets differing in glycaemic index depend on age and endogenous GIP

Aims/hypothesis High- vs low-glycaemic index (GI) diets unfavourably affect body fat mass and metabolic markers in rodents. Different effects of these diets could be age-dependent, as well as mediated, in part, by carbohydrate-induced stimulation of glucose-dependent insulinotrophic polypeptide (GIP) signalling. Methods Young-adult (16 weeks) and aged (44 weeks) male wild-type (C57BL/6J) and GIP-receptor knockout (Gipr −/− ) mice were exposed to otherwise identical high-carbohydrate diets differing only in GI (20–26 weeks of intervention, n = 8–10 per group). Diet-induced changes in body fat distribution, liver fat, locomotor activity, markers of insulin sensitivity and substrate oxidation were investigated, as well as changes in the gene expression of anorexigenic and orexigenic hypothalamic factors related to food intake. Results Body weight significantly increased in young-adult high- vs low-GI fed mice (two-way ANOVA, p < 0.001), regardless of the Gipr genotype. The high-GI diet in young-adult mice also led to significantly increased fat mass and changes in metabolic markers that indicate reduced insulin sensitivity. Even though body fat mass also slightly increased in high- vs low-GI fed aged wild-type mice (p < 0.05), there were no significant changes in body weight and estimated insulin sensitivity in these animals. However, aged Gipr −/− vs wild-type mice on high-GI diet showed significantly lower cumulative net energy intake, increased locomotor activity and improved markers of insulin sensitivity. Conclusions/interpretation The metabolic benefits of a low-GI diet appear to be more pronounced in younger animals, regardless of the Gipr genotype. Inactivation of GIP signalling in aged animals on a high-GI diet, however, could be beneficial