Multiple ionization of neon by soft X-rays at ultrahigh intensity

At the free-electron laser FLASH, multiple ionization of neon atoms was quantitatively investigated at 93.0 eV and 90.5 eV photon energy. For ion charge states up to 6+, we compare the respective absolute photoionization yields with results from a minimal model and an elaborate description. Both approaches are based on rate equations and take into acccout a Gaussian spatial intensity distribution of the laser beam. From the comparison we conclude, that photoionization up to a charge of 5+ can be described by the minimal model. For higher charges, the experimental ionization yields systematically exceed the elaborate rate based prediction.Comment: 10 pages, 3 figure

A Survey of hMLH1 mRNA Splicing Profiles in Human Cell Lines: Comparing Primary Cultured Fibroblasts Before and After Oxidative Stress and Transiently versus Stably Demethylated Colon Cancer Derived Cell Lines

Most human genes undergo alternative splicing and loss of splicing fidelity is associated with disease. Epigenetic silencing of hMLH 1 via promoter cytosine methylation is causally linked to a subset of sporadic non-polyposis colon cancer and is reversible by 5-aza-2' -deoxycytidine treatment. Here I investigated changes in hMLHI mRNA splicing profiles in normal fibroblasts and colon cancer-derived human cell lines. I established the types and frequencies of hMLHI mRNA transcripts generated under baseline conditions, after hydrogen peroxide induced oxidative stress, and in acutely 5-aza-2' -deoxycytidine-treated and stably derepressed cancer cell lines. I found that hMLHI is extensively spliced under all conditions including baseline (50% splice variants), the splice variant distribution changes in response to oxidative stress, and certain splice variants are sensitive to 5- aza-2' -deoxycytidine treatment: Splice variant diversity and frequency of exon 17 skipping correlates with the level of hMLHI promoter methylation suggesting a link between promoter methylation and mRNA splicing

Nuremberg Wheel engraved Glasses in Detail – New Criteria of Ascription for Glasses with Nuremberg Wheel Engravings of the 17th and 18 th Century

Nürnberg erlebte im 17. und 18. Jahrhundert eine Blütezeit der Technik des Glasschnitts: Die Oberflächen – meist die von Hohlgefäßen aus Glas – wurden mit feinen Darstellungen veredelt. Zu den häufigsten Motiven zählen Wappen, Patrizier- und Adelssitze und Szenen aus der Emblematik. Einige ihrer Werke signierten die Nürnberger Glasschneider mit einem Griffel mit Diamantspitze. Diesen wenigen signierten Gefäßen steht allerdings eine große Menge an unsignierten Arbeiten gegenüber. In der vorliegenden Forschungsarbeit werden durch systematische Untersuchung signierter Arbeiten von sechs Nürnberger Glasschneidern Zuschreibungskriterien entwickelt. Bei diesen handelt es sich vor allem um feine Details des Schnitts, wie z. B. die spezifische Laubgestaltung oder die Gestaltung der Körper miniaturhafter Staffagefiguren. Die Anwendbarkeit dieser Kriterien wird in einem zweiten Schritt erprobt: Dazu dienen die Gläser des Germanischen Nationalmuseums, deren Zuschreibung kritisch überprüft und entsprechend der Untersuchungsergebnisse angepasst werden. Wichtiges Werkzeug für die Untersuchungen sind Fotografien im Makrobereich, die im Abbildungsteil wiedergegeben sind.The author develops in this thesis new Criteria of Ascription for Nuremberg Wheel engraved Glasses of the 17th and 18 th Century

Japan und der Vorwurf des Trittbrettfahrerverhaltens in der US-amerikanisch-japanischen Allianz

Im Zuge der Verschiebungen der globalen Kräfteverhältnisse in den achtziger Jahren, die einerseits deutliche Einbußen in der allgemeinen Dominanz der USA und andererseits einen rasanten ökonomisch-technologischen Aufstieg Japans zur Folge hatten, wurden, vor allem aufgrund einer relativ niedrigen japanischen gesamtwirtschaftlichen Verteidigungsquote von rund 1 Prozent, in den USA zunehmend Stimmen laut, die Japan vorwarfen, sich nicht ausreichend an der US-amerikanisch-japanischen Allianz zu beteiligen und sich damit als ein sogenannter «Trittbrettfahrer» zu verhalten. Dieser Vorwurf wird in der Arbeit unter Einbeziehung der historischen Entwicklungen, der vielfältigen außen- und sicherheitspolitischen Faktoren sowie der ökonomischen Bedingungen auf seine Berechtigung untersucht

Evaluating forecasts of the evolution of the cloudy boundary layer using diurnal composites of radar and lidar observations

Observations of boundary-layer cloud have been made using radar and lidar at Chilbolton, Hampshire, UK. These have been compared with output from 7 different global and regional models. Fifty-five cloudy days have been composited to reveal the mean diurnal variation of cloud top and base heights, cloud thickness and liquid water path of the clouds. To enable like-for-like comparison between model and observations, the observations have been averaged on to the grid of each model. The composites show a distinct diurnal cycle in observed cloud; the cloud height exhibits a sinusoidal variation throughout the day with a maximum at around 1600 and a minimum at around 0700 UTC. This diurnal cycle is captured by six of the seven models analysed, although the models generally under-predict both cloud top and cloud base heights throughout the day. The two worst performing models in terms of cloud boundaries also have biases of around a factor of two in liquid water path; these were the only two models that did not include an explicit formulation for cloud-top entrainment

The bifunctional dihydrofolate reductase thymidylate synthase of Tetrahymena thermophila provides a tool for molecular and biotechnology applications

BACKGROUND: Dihydrofolate reductase (DHFR) and thymidylate synthase (TS) are crucial enzymes in DNA synthesis. In alveolata both enzymes are expressed as one bifunctional enzyme. RESULTS: Loss of this essential enzyme activities after successful allelic assortment of knock out alleles yields an auxotrophic marker in ciliates. Here the cloning, characterisation and functional analysis of Tetrahymena thermophila's DHFR-TS is presented. A first aspect of the presented work relates to destruction of DHFR-TS enzyme function in an alveolate thereby causing an auxotrophy for thymidine. A second aspect is to knock in an expression cassette encoding for a foreign gene with subsequent expression of the target protein. CONCLUSION: This system avoids the use of antibiotics or other drugs and therefore is of high interest for biotechnological applications

Biochemical and molecular characterisation of Tetrahymena thermophila extracellular cysteine proteases

BACKGROUND: Over the last decades molecular biologic techniques have been developed to alter the genome and proteome of Tetrahymena thermophila thereby providing the basis for recombinant protein expression including functional human enzymes. The biotechnological potential of Tetrahymena has been proved in numerous publications, demonstrating fast growth, high biomass, fermentation in ordinary bacterial/yeast equipment, up-scalability, existence of cheap and chemical defined media. For these reasons Tetrahymena offers promising opportunities for the development of a high expression system. Yet optimised high yield strains with protease deficiency such as commonly used in yeast and bacterial systems are not available. RESULTS: This work presents the molecular identification of predominant proteases secreted into the medium by Tetrahymena thermophila. A one-step purification of the proteolytic enzymes is described. CONCLUSION: The information provided will allow silencing of protease activity by either knock out methods or by Tetrahymena specific antisense-ribosome-techniques. This will facilitate the next step in the advancement of this exciting organism for recombinant protein production

Survived but feeling vulnerable and insecure: a qualitative study of the mental preparation for RTW after breast cancer treatment

BACKGROUND: Improvements in treatment have resulted in an increasing number of cancer survivors potentially being able to return to work after medical treatment. In this paper we focus on the considerations regarding return to work (RTW) of breast cancer absentees in the Belgian context and how these considerations are related to reactions from their social environment. METHODS: A qualitative study was performed to understand the RTW considerations of Belgian breast cancer absentees who had undergone breast cancer surgery in 2006. Twenty-two participants (mean age 46) were included and interviewed between May 2008 and August 2009 in their personal environment. An in-depth analysis (Grounded Theory) took place using the Qualitative Analysis Guide of Leuven (Quagol). RESULTS: Before the actual RTW, breast cancer employees try to build an image of the future resumption of work based on medical grounds and their knowledge of the workplace. Four matters are considered prior to RTW: (i) women want to leave the sick role and wish to keep their job; (ii) they consider whether working is worth the effort; (iii) they reflect on their capability; and (iv) they have doubts about being accepted in the workplace after returning. These inner thoughts are both product and input for the interaction with the social environment. The whole process is coloured by uncertainty and vulnerability. CONCLUSION: Our study demonstrated that mental preparation for RTW is not a linear process of improvement. It shows a detailed picture of four types of considerations made by breast cancer survivors before they actually resume work. Vulnerability appears to be an overarching theme during mental preparation. As the social environment plays an important role, people from that environment must become more aware of their influence on decreasing or increasing a woman’s vulnerability while preparing for RTW