ALBERT

Description: The small intestine is the main organ involved in the digestion and absorption of nutrients, i.e., it is in an ideal position to sense the availability of energy in the lumen in addition to its absorptive function. Consumption of a high-fat diet (HFD) influences the metabolic characteristics of the small intestine. Therefore, to better understand the metabolic features of the small intestine and their changes in response to dietary fat, we characterized the metabolism of duodenal, jejunal and hepatic cell lines and assessed the metabolic changes in the enterocytes and the liver after short-term (3 days) or medium-term (14 days) HFD feeding in mice. Experiments with immortalized enterocytes indicated a higher glycolytic capacity in the duodenal cell line compared to the other two cell lines, whereas the jejunal cell line exhibited a high oxidative metabolism. Short-term HFD feeding induced changes in the expression of glucose and lipid metabolism-related genes in the duodenum and the jejunum of mice, but not in the liver. When focusing on fatty acid oxidation both, short- and medium-term HFD feeding induced an upregulation of 3-hydroxy-3-methylglutaryl-coenzyme A, the key enzyme of ketogenesis, at the protein level in the intestinal epithelial cells, but not in the liver. These results suggest that HFD feeding induces an early adaptation of the small intestine rather than the liver in response to a substantial fat load. This highlights the importance of the small intestine in the adaptation of the body to the metabolic changes induced by HFD exposure. This article is protected by copyright. All rights reserved

Description: Abstract Despite growing interest in incorporating intraspecific variation of functional traits in community‐level studies, it remains unclear whether species classified into functional groups based on interspecific trait differences are similar regarding their variation in trait expression in response to varying plant diversity and composition in local communities. In a large biodiversity experiment (Jena Experiment) designed on a trait‐based a priori definition of functional groups (grasses, legumes, small herbs, tall herbs), we studied means, extent of variation (coefficient of variation across communities) and plasticity to increased plant diversity (slopes over a logarithmic species richness ranging from 1, 2, 4, 8 and 16 to 60 species) for nine functional traits. Species means and extent of variation in traits related to nitrogen (N) acquisition and N use differed among functional groups and were more similar in phylogenetically closely related species than expected by chance. Species in the same functional group showed a weak phylogenetic signal and varied widely in means and extent of variation in traits related to shoot architecture and to a smaller extent in leaf traits related to carbon acquisition. This indicated that functional groups were less distinguishable in light than in nitrogen acquisition strategies. The direction and degree of trait plasticity to increasing species richness did not show a phylogenetic signal and were not different among functional groups, but varied largely among species within functional groups. Correlation structures in trait means, extent of trait variation and trait plasticity revealed functional tradeoffs in the acquisition of nitrogen and light across species. While correlations between trait means and extent of trait variation varied from trait to trait (positive, negative or unrelated), trait means and trait plasticity were mostly unrelated. Our results suggest that the concept of functional groups is viable, but context‐specific trait measurements are required to improve our understanding about the functional significance of intraspecific trait variation and interspecific trait differences in local plant communities.

Description: Abscisic acid (ABA) regulates growth and developmental processes in response to limiting water conditions. ABA functions through a core signaling pathway consisting of PYR1/PYL/RCAR ABA receptors, type 2C protein phosphatases (PP2Cs), and SnRK2‐type protein kinases. Other signaling modules might converge with ABA signals through the modulation of core ABA signaling components. We have investigated the role of the protein kinase WNK8 in ABA signaling. WNK8 interacted with PP2CA and PYR1, phosphorylated PYR1 in vitro, and was dephosphorylated by PP2CA. A hypermorphic wnk8‐ct Arabidopsis mutant allele suppressed ABA and glucose hypersensitivities of pp2ca‐1 mutants during young seedling development, and WNK8 expression in protoplasts suppressed ABA‐induced reporter gene expression. We conclude that WNK8 functions as a negative modulator of ABA signaling.

Description: In a large seismic cube within the German Alpine Molasse Basin, we recognize large normal faults with lateral alternating dips that displace the Molasse sediments. They are disconnected but strike parallel to fault lineaments of the underlying carbonate platform. This raises the question how such faults could independently develop. Structural analysis suggests that the faults grew both upwards and downwards from the middle of the Molasse package, i.e., they newly initiated within the Molasse sediments and were not caused by reactivation of the faults in the carbonate platform and/or crystalline basement. Numerical modelling of the basin proves that temporarily- and spatially-confined extentional stresses existed within the Molasse sediments but not in the carbonate platform and basement during lithospheric bending. The workflow shown here gives a new and as yet undocumented insight in the tectonic and structural processes of a part of a foreland basin that was affected by buckling and bending in front of the orogen.

Description: Three months of profiler observations from Darwin, Australia are separated into seven cloud types (shallow, mid-level, and deep convective; weak and robust stratiform rain; and transitional and ice-only anvil) to provide vertical velocity statistics on the full spectrum of tropical convective clouds over the course of a monsoon season. Consistent with past studies, convective updrafts increase in height and magnitude as the convective cloud height increases. Shallow/mid-level/deep convection has a mean maximum value of 0.3 m s −1 at 3 km/0.6 m s −1 at 5 km/2.5 m s −1 at 8 km. Deep convective extremes approach 18 m s −1 above 8 km while downdrafts in all convective cloud types are maximum below 4 km. Stratiform vertical velocities are weaker and less varied than in active convection, with maximum mean values 〈 0.25 m s −1 . However, stratiform rain regions associated with larger near-surface reflectivities (and thus rain rates) have stronger mesoscale up and downdrafts than weaker stratiform rain regions. Anvil cloud with little or no rain near the surface also exhibits mesoscale up and downdrafts, but the vertical velocity profile is shifted up in height by at least 2 km. In addition, anvil updrafts were only 20 to 50% of the magnitudes in the stratiform rain region. Overall, the vertical motion statistics were similar across the pre-, active, and suppressed monsoon periods. The vertical velocity distributions for each cloud type were also generally consistent with the reflectivity distributions (i.e., the strongest updrafts were often linked to the largest reflectivities), allowing for some linkages between the dynamical and microphysical cloud properties. For example, strong updrafts above the 0  ° C level in deep convection are associated with strongly sloping reflectivity profiles supporting the importance of cold rain growth processes and stronger vertical motions are associated with stratiform rain that has a robust bright band.

Description: The importance of thorough experimental design, implementation and interpretation of laboratory experiments is known but rarely considered in continuous anaerobic digestion experiments. Especially at the evaluation of small effects on gas yields, e.g. by substrate disintegration, usual methods as single digesters or the mere comparison of mean values often reach their limits. A proper statistical interpretation will be demonstrated at four examples of semi-continuous lab-scale anaerobic digestion experiments which investigated the effects of substrate disintegration on biogas yields. Power analysis was done for one exemplary experimental set-up. In this particular case power analysis showed that with digester duplicates per treatment minimum 6% difference in biogas yield could be significantly detected.

Description: The mechanical behavior of the novel fiber CeraFib75 after various thermal exposures is examined. This fully crystalline mullite fiber was developed to exceed the thermal stability of commercially available oxide fibers. Therefore, heat treatments at temperatures ranging from 1000°C to 1400°C for 25 h were performed and results compared to the well-established Nextel ™ 720 fibers. Mechanical characterization was realized with bundle tensile tests using acoustic emission sensors to determinate the fiber failure distributions. Investigations showed that the initial fiber microstructure of mullite grains with traces of alumina transforms starting at 1200°C. Changes include dissociation of the alumina-rich mullite phase and grain growth. Thus, strength reduction is measured as a result of these microstructure transformations. Remarkably, at 1400°C, fibers become more fragile and Weibull statistics can no longer describe the failure distribution. A relation between the distribution shape and the load redistribution capability of fibers is suggested. This is more pronounced for Nextel ™ 720 fibers, which present much bigger grains and retain only 10% of their original strength. However, CeraFib75 fibers are more stable and exhibit a strength retention of 50% at the same conditions, which is attributed to the higher amount of mullite phase.

Description: We re-examine the well known empirical relationship between area-averaged surface precipitation (P) and the column moisture content (r) using ground radar and satellite observations, with an emphasis on the convective and stratiform rainfall classifications. The rapid rise in P above critical r (r c ) or the “pick-up” is more pronounced for stratiform rainfall on hourly and less time-scales while convective rainfall, displays only a weak pick-up above r c . After partitioning the area-averaged rainfall into conditional rain rates and rain area, we find that the non-linearity in the P-r curve can be almost entirely explained by the non-linear increase in rain area, especially in stratiform regions. These findings have implications for the representation of organized convective cloud systems in global circulation models.