The effects of aerobic exercise training at two different intensities in obesity and type 2 diabetes: implications for oxidative stress, low-grade inflammation and nitric oxide production

Aims To investigate the effect of 16 weeks of aerobic training performed at two different intensities on nitric oxide (tNOx) availability and iNOS/nNOS expression, oxidative stress (OS) and inflammation in obese humans with or without type 2 diabetes mellitus (T2DM). Methods Twenty-five sedentary, obese (BMI > 30 kg/m(2)) males (52.8 +/- 7.2 years); 12 controls versus 13 T2DM were randomly allocated to four groups that exercised for 30 min, three times per week either at low (Fat-Max; 30-40 % VO2max) or moderate (T-vent; 55-65 % VO2max) intensity. Before and after training, blood and muscle samples (v. lateralis) were collected. Results Baseline erythrocyte glutathione was lower (21.8 +/- 2.8 vs. 32.7 +/- 4.4 nmol/ml) and plasma protein oxidative damage and IL-6 were higher in T2DM (141.7 +/- 52.1 vs. 75.5 +/- 41.6 nmol/ml). Plasma catalase increased in T2DM after T-vent training (from 0.98 +/- 0.22 to 1.96 +/- 0.3 nmol/min/ml). T2DM groups demonstrated evidence of oxidative damage in response to training (elevated protein carbonyls). Baseline serum tNOx were higher in controls than T2DM (18.68 +/- 2.78 vs. 12.34 +/- 3.56 mu mol/l). Training at T-vent increased muscle nNOS and tNOx in the control group only. Pre-training muscle nNOS was higher in controls than in T2DMs, while the opposite was found for iNOS. No differences were found after training for plasma inflammatory markers. Conclusion Exercise training did not change body composition or aerobic fitness, but improved OS markers, especially when performed at T-vent. Non-diabetics responded to T-vent training by increasing muscle nNOS expression and tNOx levels in skeletal muscle while these parameters did not change in T2DM, perhaps due to higher insulin resistance (unchanged after intervention)

Determination of greenhouse gas sources and sinks in Swiss arable soils under organic and non-organic management

Agricultural practices contribute considerably to emissions of greenhouse gases (GHG). Knowledge on the impact of organic (ORG) compared to non-organic (NON-ORG) farming on soil-derived nitrous oxide (N2O) and methane (CH4) emissions is still limited. We conducted a literature search on measured soil GHG fluxes under ORG and NON-ORG from farming system comparisons and performed a meta-analysis. Based on 12 studies covering annual measurements, it appeared that area-scaled N2O emissions are with 14% significantly lower under ORG. However, yield-scaled N2O emissions are only 9% higher for ORG. Emissions from NON-ORG soils seemed to be influenced mainly by total N inputs, whereas for ORG other soil characteristics seemed to be more important because N2O from organic N fertilisers emits decoupled from the inputs. Furthermore, we observed a 12% higher CH4 uptake for arable soils under ORG

GREENHOUSE GAS FLUXES IN AGRICULTURAL SOILS UNDER ORGANIC AND NON-ORGANIC MANAGEMENT

Farming practices are known to exert strong control over the soils’ function to act as sources or sinks for greenhouse gases (GHG). This paper deals with the outcome of a recent meta-analysis based on the evaluation of 19 published long-term farming system comparisons. It provides a comprehensive data base regarding GHG fluxes from soils under organic and non-organic management. There is scientific evidence for lower nitrous oxide emissions from organically managed soils when scaled to the area. However, further data from farming system comparisons are required, particularly from long-term GHG measurements covering several cropping seasons or ideally entire crop rotations. This enables closing knowledge gaps concerning N fluxes and pools under organic management as well as the formation of the new soil ecosystem (soil quality) equilibrium after implementing organic practices. Substantial reductions of nitrous oxide emissions as well as enhancement of methane uptake can be reached by consequent application of “good agricultural practice” and simple adoptions of soil management, forming together a balanced set of GHG mitigation mechanisms. In addition we provide first GHG flux data from the well-known DOK farming system trial in Therwil/CH and the role of microbial communities driving soil functioning

A study on shape-dependent settling of single particles with equal volume using surface resolved simulations

A detailed knowledge of the influence of a particle’s shape on its settling behavior is useful for the prediction and design of separation processes. Models in the available literature usually fit a given function to experimental data. In this work, a constructive and data-driven approach is presented to obtain new drag correlations. To date, the only considered shape parameters are derivatives of the axis lengths and the sphericity. This does not cover all relevant effects, since the process of settling for arbitrarily shaped particles is highly complex. This work extends the list of considered parameters by, e.g., convexity and roundness and evaluates the relevance of each. The aim is to find models describing the drag coefficient and settling velocity, based on this extended set of shape parameters. The data for the investigations are obtained by surface resolved simulations of superellipsoids, applying the homogenized lattice Boltzmann method. To closely study the influence of shape, the particles considered are equal in volume, and therefore cover a range of Reynolds numbers, limited to [9.64, 22.86]. Logistic and polynomial regressions are performed and the quality of the models is investigated with further statistical methods. In addition to the usually studied relation between drag coefficient and Reynolds number, the dependency of the terminal settling velocity on the shape parameters is also investigated. The found models are, with an adjusted coefficient of determination of 0.96 and 0.86, in good agreement with the data, yielding a mean deviation below 5.5% on the training and test dataset

InGaN as a Substrate for AC Photoelectrochemical Imaging.

AC photoelectrochemical imaging at electrolyte-semiconductor interfaces provides spatially resolved information such as surface potentials, ion concentrations and electrical impedance. In this work, thin films of InGaN/GaN were used successfully for AC photoelectrochemical imaging, and experimentally shown to generate a considerable photocurrent under illumination with a 405 nm modulated diode laser at comparatively high frequencies and low applied DC potentials, making this a promising substrate for bioimaging applications. Linear sweep voltammetry showed negligible dark currents. The imaging capabilities of the sensor substrate were demonstrated with a model system and showed a lateral resolution of 7 microns

L-Arginine Is Essential for Pancreatic b-Cell Functional Integrity, Metabolism and Defense From Inflammatory Challenge

In this work, our aim was to determine whether L-arginine (a known insulinotropic amino acid) can promote a shift of b-cell intermediary metabolism favoring glutathione (GSH) and glutathione disulfide (GSSG) antioxidant responses, stimulus–secretion coupling and functional integrity. Clonal BRIN-BD11 b-cells and mouse islets were cultured for 24 h at various L-arginine concentrations (0–1.15 mmol/l) in the absence or presence of a proinflammatory cytokine cocktail (interleukin 1b, tumour necrosis factor a and interferon g). Cells were assessed for viability, insulin secretion, GSH, GSSG, glutamate, nitric oxide (NO), superoxide, urea, lactate and for the consumption of glucose and glutamine. Protein levels of NO synthase-2, AMP-activated protein kinase (AMPK) and the heat shock protein 72 (HSP72) were also evaluated. We found that L-arginine at 1.15 mmol/l attenuated the loss of b-cell viability observed in the presence of proinflammatory cytokines. L-Arginine increased total cellular GSH and glutamate levels but reduced the GSSG/GSH ratio and glutamate release. The amino acid stimulated glucose consumption in the presence of cytokines while also stimulating AMPK phosphorylation and HSP72 expression. Proinflammatory cytokines reduced, by at least 50%, chronic (24 h) insulin secretion, an effect partially attenuated by L-arginine. Acute insulin secretion was robustly stimulated by L-arginine but this effect was abolished in the presence of cytokines. We conclude that L-arginine can stimulate b-cell insulin secretion, antioxidant and protective responses, enabling increased functional integrity of b-cells and islets in the presence of proinflammatory cytokines. Glucose consumption and intermediary metabolism were increased by L-arginine. These results highlight the importance of L-arginine availability for b-cells during inflammatory challeng

Ist der Biolandbau klimafreundlicher?

Die Schweizer Landwirtschaft verursacht 11,2 Prozent* der gesamten Treibhausgasemissionen, wobei Methan (CH4) aus der Fermentation in Wiederkäuermägen 45 Prozent und Lachgas (N20) aus den Böden 38 Prozent der landwirtschaftlichen Emissionen ausmachen. Die Lachgasemissionen aus gedüngten Böden sind daher von Bedeutung und eine Reduktion durch ein angepasstes Management absolut notwendig

Ist der Biolandbau klimafreundlicher?

Eine kürzlich am Forschungsinstitut für biologischen Landbau (FiBL) in Frick abgeschlossene Literaturstudie zeigt, dass biologisch bewirtschaftete Flächen aufgrund des geringeren Stickstoffeintrags flächenbezogen weniger Lachgas produzieren und tendenziell mehr Methan aus der Atmosphäre aufnehmen

Ancient Maya wetland fields revealed under tropical forest canopy from laser scanning and multiproxy evidence

Understanding agricultural subsistence is vital for understanding past complex societies. Lidar data are indicating widespread ancient Maya infrastructure. Wetland agriculture was crucial to ancient cultures, but no previous study coupled lidar with multiproxy evidence to demonstrate the extent and uses of Maya wetland fields. We conducted a lidar survey around wetlands that multiple use proxies established were ancient Maya polycultural systems. Lidar indicated the Birds of Paradise (BOP) wetland field complex was five times larger than we had previously mapped and identified an even larger wetland agroecosystem. We ground-verified the BOP fields through excavations and dating, creating a study to couple these multiproxy data with lidar, thereby demonstrating widespread ancient Maya wetland agroecosystems.We report on a large area of ancient Maya wetland field systems in Belize, Central America, based on airborne lidar survey coupled with multiple proxies and radiocarbon dates that reveal ancient field uses and chronology. The lidar survey indicated four main areas of wetland complexes, including the Birds of Paradise wetland field complex that is five times larger than earlier remote and ground survey had indicated, and revealed a previously unknown wetland field complex that is even larger. The field systems date mainly to the Maya Late and Terminal Classic (∼1,400–1,000 y ago), but with evidence from as early as the Late Preclassic (∼1,800 y ago) and as late as the Early Postclassic (∼900 y ago). Previous study showed that these were polycultural systems that grew typical ancient Maya crops including maize, arrowroot, squash, avocado, and other fruits and harvested fauna. The wetland fields were active at a time of population expansion, landscape alteration, and droughts and could have been adaptations to all of these major shifts in Maya civilization. These wetland-farming systems add to the evidence for early and extensive human impacts on the global tropics. Broader evidence suggests a wide distribution of wetland agroecosystems across the Maya Lowlands and Americas, and we hypothesize the increase of atmospheric carbon dioxide and methane from burning, preparing, and maintaining these field systems contributed to the Early Anthropocene.Office of the VP for Researc