Crystallography on Curved Surfaces

We study static and dynamical properties that distinguish two dimensional crystals constrained to lie on a curved substrate from their flat space counterparts. A generic mechanism of dislocation unbinding in the presence of varying Gaussian curvature is presented in the context of a model surface amenable to full analytical treatment. We find that glide diffusion of isolated dislocations is suppressed by a binding potential of purely geometrical origin. Finally, the energetics and biased diffusion dynamics of point defects such as vacancies and interstitials is explained in terms of their geometric potential.Comment: 12 Pages, 8 Figure

Radiation tolerance studies of silicon microstrip sensors for the CBM Silicon Tracking System

Double-sided silicon microstrip sensors will be used in the Silicon Tracking System of the CBM experiment. During experimental run they will be exposed to a radiation field of up to 1x1014 1 MeV neq cm-2. Radiation tolerance studies were made on prototypes from two different vendors. Results from these prototype detectors before and after irradiation to twice that neutron fluence are discussed

The population of white dwarf binaries with hot subdwarf companions

Hot subdwarfs (sdBs) are core helium-burning stars, which lost almost their entire hydrogen envelope in the red-giant phase. Since a high fraction of those stars are in close binary systems, common envelope ejection is an important formation channel. We identified a total population of 51 close sdB+WD binaries based on time-resolved spectroscopy and multi-band photometry, derive the WD mass distribution and constrain the future evolution of these systems. Most WDs in those binaries have masses significantly below the average mass of single WDs and a high fraction of them might therefore have helium cores. We found 12 systems that will merge in less than a Hubble time and evolve to become either massive C/O WDs, AM\,CVn systems, RCrB stars or even explode as supernovae type Ia.Comment: 5 pages, 2 figures, to appear in the proceedings of the 19th European White Dwarf Workshop, ASP Conf. Se

The C/EBPβ LIP isoform rescues loss of C/EBPβ function in the mouse

The transcription factor C/EBPβ regulates hematopoiesis, bone, liver, fat, and skin homeostasis, and female reproduction. C/EBPβ protein expression from its single transcript occurs by alternative in-frame translation initiation at consecutive start sites to generate three isoforms, two long (LAP*, LAP) and one truncated (LIP), with the same C-terminal bZip dimerization domain. The long C/EBPβ isoforms are considered gene activators, whereas the LIP isoform reportedly acts as a dominant-negative repressor. Here, we tested the putative repressor functions of the C/EBPβ LIP isoform in mice by comparing monoallelic WT or LIP knockin mice with Cebpb knockout mice, in combination with monoallelic Cebpa mice. The C/EBPβ LIP isoform was sufficient to function in coordination with C/EBPα in murine development, adipose tissue and sebocyte differentiation, and female fertility. Thus, the C/EBPβ LIP isoform likely has more physiological functions than its currently known role as a dominant-negative inhibitor, which are more complex than anticipated

Multitouch Experiment Instructions to Promote Self-Regulation in Inquiry-Based Learning in School Laboratories

Multitouch experiment instructions (MEIs), implemented as interactive eBooks, are learning tools for pupils that offer various digital support tools and enable pupils to individualize their learning. They may be applied to contexts such as inquiry-based experiments in school laboratories, which involve highly demanding cognitive processes and require a high level of self-regulation. Self-regulation has been shown to be reliably promoted by interventions which include the targeted training of self-regulation strategies. A MEI was designed as an interactive eBook on experiments on the topic “Analysis of Cola”, suitable for an inquiry-based learning environment such as a school lab. The MEI’s potential to promote self-regulated learning was investigated by comparing it to a MEI with digital, integrated self-regulation training. The data revealed a significant increase of self-regulation in the control group, which consisted of pupils experimenting with the MEI on its own, and one experimental group, which included pupils that were supported by the MEI with an additional self-regulation training. It can be assumed that the MEI’s ability to promote self-regulated learning is comparable to the results achieved by an additional self-regulation training which explicitly addressed self-regulation strategies. This highlights the MEI’s potential to promote self-regulated learning in an indirect approach

Logical Rules and a Preliminary Prototype for Translating Mortality Coding Rules from ICD-10 to ICD-11

Iris is a system for coding multiple causes of death in ICD-10 and for the selection of the underlying cause of death, based on a knowledge base composed by a large number of rules. With the adoption of ICD-11, those rules need translation to ICD-11. A pre-project has been carried out to evaluate feasibility of transition to ICD-11, which included the analysis of the logical meta-rules needed for rule translation and development of a prototype support system for the expert that will translate the coding rules