Track Based Alignment of the ATLAS Silicon Detectors with the Robust Alignment Algorithm

The Robust Alignment algorithm for the ATLAS silicon detectors is presented. It is an iterative method based on centering residual and overlap residual distributions. Tests on simulated and real data are discussed

Neuroendokrine Tumore und Knochenmetastasen : Verhalten in der funktionellen Bildgebung und Ansprechen auf die Peptid-Radiorezeptor-Therapie

Neuroendokrine Tumore sind eine sehr inhomogene Gruppe, die aus Zellen des neuroendokrinen Systems abstammen. Sie sind eine seltene Tumorart, die sich durch eine meist langsame Proliferation und im fortgeschrittenen Stadium durch ossäre Metastasen auszeichnen. Die Peptid-Radiorezeptor-Therapie macht sich zu Nutze, dass die meisten Zellen der neuroendokrinen Tumore eine Überexpression des Somatostatinrezeptors zeigen. Eine Kopplung eines Nuklids mit einem Somatostatinanalogon, die Applikation und folgende Anreicherung am Tumorgewebe stellt die Grundlage dieser Therapie dar. Durch Anwendung der modifizierten MD-Anderson-Kriterien der funktionellen Bildgebung konnte in dieser Arbeit erstmals gezeigt werden, dass die Peptid-Radiorezeptor-Therapie auch für ossäre Metastasen einen hochwirksamen Therapieansatz darstellt. Hinsichtlich der Detektion der ossären Metastasierung konnte gezeigt werden, dass die Lutetium-177-Radiorezeptor-Szintigraphie eine sehr sensitive Bildgebung ist. Niedrige Chromogranin A und Ki67-Proliferationsindex Werte können als prognostische Parameter für ein längeres progressions-freies Überleben angesehen werden. Weder Ausmaß der Metastasierung noch Allgemeinzustand des Patienten hatten einen Einfluss auf das Ansprechen der Peptid-Radiorezeptor-Therapie. Dies zeigt den Nutzen der Therapie auch in einem fortgeschrittenen Stadium der Erkrankung

Genetic diversity and gain : the concept of a status number

A trade-off always tends to exist involving genetic gains and selection intensity, on the one hand, and the remaining effective population size (usually known as Ne), on the other. A new approach is presented and analysed for different breeding situations, using stochastic simulations, in terms of mating designs and subline sizes, guiding breeders through a new concept of status number (Ns) and its trade-off with gain. Status number is defined as half the inverse of the average coancestry and depicts the current state of the population. The status number concept can easily be applied to deployment of different genotypes with unequal representation. Breeding schemes with small breeding groups are slightly more efficient in preserving status number through multiple generations than breeding schemes with large groups. Medium- to large-size breeding groups showed a comparatively small reduction in aggregated status number over generations but showed greater increases in gain compared with small groups. Inbreeding in small elites becomes so great that it is likely to cause fertility problems and disturb selection considerably. Small breeding groups will probably not be useful for a sustainable long-term breeding strategy. Substantial benefits on status number for subdividing the population into small breeding groups will only be seen after numerous generations. Selection schemes that maximise gain by unrestricted combined index selection will result in rapid inbreeding, and may not be sustainable in the long term. Selection procedures that place less emphasis on family information would best meet long-term diversity targets. However, gains may be too low for mating systems and selection procedures that do not include a between-family component, especially with low heritabilities. This is a good reason for using a large number of families as founders of the breeding population. Going from selection within only 0.5 or 1 available cross per parent per generation (made equivalent to within-family selection) to 2.5 crosses per parent (restricting the number of individuals chosen per full-sib family) resulted in substantial increases in genetic gain, depending on heritability. However, increasing the number of crosses per parent up to 2.5 does carry a modest penalty of increased coefficient of inbreeding and reduced status number. Higher levels of gain per unit of status number loss are obtained with a conservative within family selection strategy but to reach the same level of gain more cycles of breeding will be required. Effects of departures from assumptions (zero inbreeding coefficient and coancestry for the founders, genes being independently assorted, no mutation and interactions, or combinations from departures of the neutrality assumption) , singly and in various combinations will occur, meaning that calculations and predictions based on pedigrees will be biased. Future work will require modelling the effects for departures from the idealised assumptions and laboratory-based quantification of departures from some key assumptions

Conditions of Mytilus edulis extracellular body fluids and shell composition in a pH-treatment experiment: Acid-base status, trace elements and delta B-11

Mytilus edulis were cultured for 3 months under six different seawater pCO(2) levels ranging from 380 to 4000 mu atm. Specimen were taken from Kiel Fjord (Western Baltic Sea, Germany) which is a habitat with high and variable seawater pCO(2) and related shifts in carbonate system speciation (e. g., low pH and low CaCO3 saturation state). Hemolymph (HL) and extrapallial fluid (EPF) samples were analyzed for pH and total dissolved inorganic carbon (C-T) to calculate pCO(2) and [HCO3-]. A second experiment was conducted for 2 months with three different pCO(2) levels (380, 1400 and 4000 mu atm). Boron isotopes (delta B-11) were investigated by LA-MC-ICP-MS (Laser Ablation-Multicollector-Inductively Coupled Plasma-Mass Spectrometry) in shell portions precipitated during experimental treatment time. Additionally, elemental ratios (B/Ca, Mg/Ca and Sr/Ca) in the EPF of specimen from the second experiment were measured via ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry). Extracellular pH was not significantly different in HL and EPF but systematically lower than ambient water pH. This is due to high extracellular pCO(2) values, a prerequisite for metabolic CO2 excretion. No accumulation of extracellular [HCO3-] was measured. Elemental ratios (B/Ca, Mg/Ca and Sr/Ca) in the EPF increased slightly with pH which is in accordance with increasing growth and calcification rates at higher seawater pH values. Boron isotope ratios were highly variable between different individuals but also within single shells. This corresponds to a high individual variability in fluid B/Ca ratios and may be due to high boron concentrations in the organic parts of the shell. The mean delta B-11 value shows no trend with pH but appears to represent internal pH (EPF) rather than ambient water pH

The effect of mechanical treatment of powder on the structure and phase composition of hard alloys

It has been studied an effect of mechanical treatment of powder on the structure and phase composition of hard alloys. It has been shown that after sintering of powders were formed an alloy with WC and Co phases. The lattice parameter of the WC-phase is correlates well with values in literature. It has been shown that the hardness depends on grain size, porosity and second carbide content

TapA acts as specific chaperone in TasA filament formation by strand complementation

Studying mechanisms of bacterial biofilm generation is of vital importance to understanding bacterial cell–cell communication, multicellular cohabitation principles, and the higher resilience of microorganisms in a biofilm against antibiotics. Biofilms of the nonpathogenic, gram-positive soil bacterium Bacillus subtilis serve as a model system with biotechnological potential toward plant protection. Its major extracellular matrix protein components are TasA and TapA. The nature of TasA filaments has been of debate, and several forms, amyloidic and non-Thioflavin T-stainable have been observed. Here, we present the three-dimensional structure of TapA and uncover the mechanism of TapA-supported growth of nonamyloidic TasA filaments. By analytical ultracentrifugation and NMR, we demonstrate TapA-dependent acceleration of filament formation from solutions of folded TasA. Solid-state NMR revealed intercalation of the N-terminal TasA peptide segment into subsequent protomers to form a filament composed of β-sandwich subunits. The secondary structure around the intercalated N-terminal strand β0 is conserved between filamentous TasA and the Fim and Pap proteins, which form bacterial type I pili, demonstrating such construction principles in a gram-positive organism. Analogous to the chaperones of the chaperone-usher pathway, the role of TapA is in donating its N terminus to serve for TasA folding into an Ig domain-similar filament structure by donor-strand complementation. According to NMR and since the V-set Ig fold of TapA is already complete, its participation within a filament beyond initiation is unlikely. Intriguingly, the most conserved residues in TasA-like proteins (camelysines) of Bacillaceae are located within the protomer interface

International Student Mobility: An Identity Development Task?

Based on the review of literature on internationalization of education and on identity formation pro cesses in young adults, this cross - sectional study aims to investigate to which extent self - perceived dimensions of identity are associated to the main moti vations to study abroad. The participants in this study were 429 international university students of different nationalities. Findings revealed that the motivation to study abroa d for personal growth is strongly associated to the commitment and in - depth e xploration identity processes, whereas the motivation to study abroad with the aim of changing life style and enlarging job opportunities is positively associated with reconsideration of commitment and in - depth exploration. Furthermore, identity achieved s tudents showed the highest motivation to s tudy abroad for personal growth, while the motivation to study abroad to positively change life - styles and work conditions is strongly associated with the positive facet of identity crisis, which is otherwise calle d searching - moratorium status. Based on these results, the present survey provides useful questions and hypothesis for future researc

Boron isotope ratio determination in carbonates /via/ LA-MC-ICP-MS using soda-lime glass standards as reference material

A new in situ method using LA-MC-ICP-MS (193 nm excimer laser) for the determination of stable boron isotope ratios (δ11B) in carbonates was developed. Data were acquired via a standard sample standard bracketing procedure typically providing a reproducibility of 0.5‰ (SD) for samples containing 35 ppm of boron. A single ablation interval consumed about 5 µg of sample corresponding to about 0.2 ng of boron. The major finding was the similar instrumental fractionation behaviour of carbonates, soda-lime glass and sea salt with respect to boron isotopes. As no matrix induced offset was detectable between these distinct materials we propose the use of NIST glasses as internal standards for boron isotope ratio measurements via LA-MC-ICP-MS. This finding overcomes the problem of a missing matrix matched carbonate standard for in situ boron isotope studies. As a first application a set of coral samples from a culturing experiment was analysed. δ11B values range from 19.5 to 25‰ depending on the pH of the water used in the particular treatment. This is in good agreement with the results of earlier studies