A method to correct differential nonlinearities in subranging analog-to-digital converters used for digital gamma-ray spectroscopy

The influence on $\gamma$-ray spectra of differential nonlinearities (DNL) in subranging, pipelined analog-to-digital converts (ADCs) used for digital $\gamma$-ray spectroscopy was investigated. The influence of the DNL error on the $\gamma$-ray spectra, depending on the input count-rate and the dynamic range has been investigated systematically. It turned out, that the DNL becomes more significant in $\gamma$-ray spectra with larger dynamic range of the spectroscopy system. An event-by-event offline correction algorithm was developed and tested extensively. This correction algorithm works especially well for high dynamic ranges

First-principles, atomistic thermodynamics for oxidation catalysis

Present knowledge of the function of materials is largely based on studies (experimental and theoretical) that are performed at low temperatures and ultra-low pressures. However, the majority of everyday applications, like e.g. catalysis, operate at atmospheric pressures and temperatures at or higher than 300 K. Here we employ ab initio, atomistic thermodynamics to construct a phase diagram of surface structures in the (T,p)-space from ultra-high vacuum to technically-relevant pressures and temperatures. We emphasize the value of such phase diagrams as well as the importance of the reaction kinetics that may be crucial e.g. close to phase boundaries.Comment: 4 pages including 2 figure files. Submitted to Phys. Rev. Lett. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

Method for Selecting Improvement Measures for Discrete Production Environments Using an Extended Energy Value Stream Model

AbstractImproving energy efficiency in discrete manufacturing environments has been one of the key goals of recent research and industrial activities in production management, leading to a large and still increasing amount of different methodologies and improvement measures in that field (here called “Solution Elements”). Despite the growing interest, most of these are rarely applied, or are implemented in an improper manner instead of identifying and realizing the most appropriate ones from a holistic, factory wide perspective. For coping with these challenges a flexible, multi criteria and multi step selection process is introduced by which the applicability of solution elements is evaluated for a specific discrete production environment. The selection process is based on an approach taking multiple criteria derived from the current (as-is) situation in a factory as well as from user preferences into account. For data gathering an extended energy value stream approach is utilized that allows the derivation of value stream specific energy and cost drivers. The approach was tested in an industrial use-case, which is introduced in this paper

DNA strand displacement, strand annealing and strand swapping by the Drosophila Bloom's syndrome helicase

Genetic analysis of the Drosophila Bloom's syndrome helicase homolog (mus309/DmBLM) indicates that DmBLM is required for the synthesis-dependent strand annealing (SDSA) pathway of homologous recombination. Here we report the first biochemical study of DmBLM. Recombinant, epitope-tagged DmBLM was expressed in Drosophila cell culture and highly purified protein was prepared from nuclear extracts. Purified DmBLM exists exclusively as a high molecular weight (∼1.17 MDa) species, is a DNA-dependent ATPase, has 3′→5′ DNA helicase activity, prefers forked substrate DNAs and anneals complementary DNAs. High-affinity DNA binding is ATP-dependent and low-affinity ATP-independent interactions contribute to forked substrate DNA binding and drive strand annealing. DmBLM combines DNA strand displacement with DNA strand annealing to catalyze the displacement of one DNA strand while annealing a second complementary DNA strand

Understanding the emergence of bacterial pathogens in novel hosts

This is the author accepted manuscript.Data accessibility statement: The computer code to generate the stochastic simulation model can be downloaded fromOur understanding of the ecological and evolutionary context of novel infections is largely based on viral diseases, even though bacterial pathogens may display key differences in the processes underlying their emergence. For instance, host-shift speciation, in which the jump of a pathogen into a novel host species is followed by the specialisation on that host and the loss of infectivity of previous host(s), is commonly observed in viruses, but less often in bacteria. Here, we suggest that adaptation to dealing with different environments, rates of molecular evolution and recombination may influence the extent to which pathogens evolve host generalism or specialism following a jump into a novel host. We then test these hypotheses using a formal model and show that the high levels of phenotypic plasticity, low rates of evolution and the ability to recombine typical of bacterial pathogens should reduce their propensity to specialise on novel host. Novel bacterial infections may therefore be more likely to result in transient spillovers or increased host ranges than in host shifts. Finally, consistent with our predictions, we show that, in two unusual cases of contemporary bacterial host shifts, the bacterial pathogens both have small genomes and rapid rates of substitution. Further tests are required across a greater number of emerging pathogens to assess the validity of our predictions.Natural Environment Research Council (NERC)Wellcome TrustRoyal SocietyLeverhulme Trus

The Hindgut Microbiome of Grazing Horses

The hindgut microbiome plays an essential role in horses consuming forage-based diets high in fiber, such as pasture. The equine hindgut harbors a large microbial community that ferments dietary fiber and produces by-products which provide a substantial portion of daily energy requirements. Despite the importance in nutrition and health, research evaluating the hindgut microbiome of grazing horses is relatively limited. Grazing horse microbiome research has primarily focused on inter-diet comparisons with mixed diets including concentrates as well as with other forms of forage. Recent research has begun to explore responses of the gut microbiome to different pasture forage species and relationships with horse metabolism. Further research is needed to unravel the complex relationships between pasture management practices, impacts on the hindgut microbiome, and horse health outcomes. The objective of this presentation will be to discuss recent research and highlight future research needs and opportunities related to the microbiome of the grazing horse

Horse and Pasture Responses to Stocking Methods: Rotational versus Continuous

Rotational grazing management offers potential advantages for economic and environmental sustainability, as well as for horse health. Rotational grazing has the potential to increase pasture yields and available forage for grazing, and therefore reduce supplemental feed costs. A rotational grazing management strategy can also prevent or mitigate negative effects of overgrazing, with implications for pasture productivity and the environment. Overgrazing can reduce vegetative cover over time, increasing the potential for erosion and nutrient run-off. Overgrazing may also result in long-term decreased forage stand persistence and weed invasion, necessitating more frequent pasture renovation. All of this can negatively impact the horse’s nutrition and therefore their condition. This presentation will highlight fundamentals of rotational grazing and recent research on the benefits of this practice on horse condition and pasture productivity

Inhibition of DNA damage response at telomeres improves the detrimental phenotypes of Hutchinson–Gilford Progeria Syndrome

Hutchinson–Gilford progeria syndrome (HGPS) is a genetic disorder characterized by premature aging features. Cells from HGPS patients express progerin, a truncated form of Lamin A, which perturbs cellular homeostasis leading to nuclear shape alterations, genome instability, heterochromatin loss, telomere dysfunction and premature entry into cellular senescence. Recently, we reported that telomere dysfunction induces the transcription of telomeric non-coding RNAs (tncRNAs) which control the DNA damage response (DDR) at dysfunctional telomeres. Here we show that progerin-induced telomere dysfunction induces the transcription of tncRNAs. Their functional inhibition by sequence-specific telomeric antisense oligonucleotides (tASOs) prevents full DDR activation and premature cellular senescence in various HGPS cell systems, including HGPS patient fibroblasts. We also show in vivo that tASO treatment significantly enhances skin homeostasis and lifespan in a transgenic HGPS mouse model. In summary, our results demonstrate an important role for telomeric DDR activation in HGPS progeroid detrimental phenotypes in vitro and in vivo

Jahn-Teller stabilization of a "polar" metal oxide surface: Fe3O4(001)

Using ab initio thermodynamics we compile a phase diagram for the surface of Fe3O4(001) as a function of temperature and oxygen pressures. A hitherto ignored polar termination with octahedral iron and oxygen forming a wave-like structure along the [110]-direction is identified as the lowest energy configuration over a broad range of oxygen gas-phase conditions. This novel geometry is confirmed in a x-ray diffraction analysis. The stabilization of the Fe3O4(001)-surface goes together with dramatic changes in the electronic and magnetic properties, e.g., a halfmetal-to-metal transition.Comment: 4 pages, 4 figure