The production and composition of rat sebum is unaffected by 3 Gy gamma radiation

The aim of this work was to use metabolomics to evaluate sebum as a source of biomarkers for gamma-radiation exposure in the rat, and potentially in man. Proof of concept of radiation metabolomics was previously demonstrated in both mouse and rat urine, from the radiation dose- and time-dependent excretion of a set of urinary biomarkers.

Production and characterization of a custom-made 228Th source with reduced neutron source strength for the Borexino experiment

A custom-made 228Th source of several MBq activity was produced for the Borexino experiment for studying the external background of the detector. The aim was to reduce the unwanted neutron emission produced via (alpha,n) reactions in ceramics used typically for commercial 228Th sources. For this purpose a ThCl4 solution was converted chemically into ThO2 and embedded into a gold foil. The paper describes the production and the characterization of the custom-made source by means of gamma-activity, dose rate and neutron source strength measurements. From gamma-spectroscopic measurements it was deduced that the activity transfer from the initial solution to the final source was >91% (at 68% C.L.) and the final activity was (5.41+-0.30) MBq. The dose rate was measured by two dosimeters yielding 12.1 mSv/h and 14.3 mSv/h in 1 cm distance. The neutron source strength of the 5.41 MBq 228Th source was determined as (6.59+-0.85)/sec.

Cloning, production and characterization of antigen 5 like proteins from Simulium vittatum and Culicoides nubeculosus, the first cross-reactive allergen associated with equine insect bite hypersensitivity

Insect bite hypersensitivity (IBH) is an IgE-mediated seasonal dermatitis of the horses associated with bites of Simulium (black fly) and Culicoides (midge) species. Although cross-reactivity between Simulium and Culicoides salivary gland extracts has been demonstrated, the molecular nature of the allergens responsible for the observed cross-reactivity remains to be elucidated. In this report we demonstrate for the first time in veterinary medicine that a homologous allergen, present in the salivary glands of both insects, shows extended IgE cross-reactivity in vitro and in vivo. The cDNA sequences coding for both antigen 5 like allergens termed Sim v 1 and Cul n 1 were amplified by PCR, subcloned in high level expression vectors, and produced as [His](6)-tagged proteins in Escherichia coli. The highly pure recombinant proteins were used to investigate the prevalence of sensitization in IBH-affected horses by ELISA and their cross-reactive nature by Western blot analyses, inhibition ELISA and intradermal skin tests (IDT). The prevalence of sensitization to Sim v 1 and Cul n 1 among 48 IBH-affected horses was 37% and 35%, respectively. In contrast, serum IgE levels to both allergens in 24 unaffected horses did not show any value above background. Both proteins strongly bound serum IgE from IBH-affected horses in Western blot analyses, demonstrating the allergenic nature of the recombinant proteins. Extended inhibition ELISA experiments clearly showed that Sim v 1 in fluid phase is able to strongly inhibit binding of serum IgE to solid phase coated Cul n 1 in a concentration dependent manner and vice versa. This crucial experiment shows that the allergens share common IgE-binding epitopes. IDT with Sim v 1 and Cul n 1 showed clear immediate and late phase reactions to the allergen challenges IBH-affected horses, whereas unaffected control horses do not develop relevant immediate hypersensitivity reactions. In some horses, however, mild late phase reactions were observed 4h post-challenge, a phenomenon reported to occur also in challenge experiments with Simulium and Culicoides crude extracts probably related to lipopolysaccaride contaminations which are also present in E. coli-expressed recombinant proteins. In conclusion our data demonstrate that IgE-mediated cross-reactivity to homologous allergens, a well-known clinically relevant phenomenon in human allergy, also occurs in veterinary allergy.

Firm-level strategic orientation and performance: a synthesis and extension of the knowledge base on entrepreneurial, market and learning orientation

Should a firm stay focused or should it rather adopt a broader strategic perspective? This dissertation summarizes and extends the existing knowledge base on entrepreneurial, market, and learning orientation. Building on multiple theoretical perspectives, empirical evidence from prior studies, as well as on survey and archival data collected in two economic contexts, performance effects from individual orientations, their dimensions and combinations are explored. Results reveal that the three strategic orientations are highly interrelated and that their relationship to firm performance is more complex than previously assumed.

The effect of extracellular nucleotides on cytokine production and phagocytosis of macrophages

Bacterial sepsis is a severe clinical condition, leading to severe sepsis, septic shock, and death. The complex pathophysiology of sepsis is not yet fully understood. Cytokines, released by immune cells such as macrophages, play an important role in the pathophysiology of sepsis. Kupffer cells are the largest population of macrophages in the body. Purinergic signaling, mediated by different nucleosides and nucleotides, and purinergic receptors, has been shown to have various effects on cytokine release, inflammatory processes and the immune system. In our work with in vitro experiments we studied the effect of extracellular nucleotides on the release of TNFα by primary murine Kupffer cells, and the effect of extracellular nucleotides on the phagocytosis of murine RAW 264.7 and human U-937 cell culture macrophages. Secretion of TNFα was measured using ELISA, phagocytosis of bio particles was measured using a plate reader phagocytosis assay and flow cytometry. Our experiments show, that extracellular LPS stimulate release of TNFα in murine Kupffer cells and that extracellular nucleotides inhibit this effect in a dose dependent matter. Our other experiments show phagocytosis of fluorescence labeled bio particles by both macrophage cell lines RAW 264.7 and U-937 in a dose dependent manner. The experiments could not show an effect of extracellular nucleotides on phagocytosis of cell culture macrophages.

Decomposition studies of group 6 hexacarbonyl complexes. Part 1: Production and decomposition of Mo(CO)6 and W(CO)6

Chemical studies of superheavy elements require fast and efficient techniques, due to short half-lives and low production rates of the investigated nuclides. Here, we advocate for using a tubular flow reactor for assessing the thermal stability of the Sg carbonyl complex – Sg(CO)6. The experimental setup was tested with Mo and W carbonyl complexes, as their properties are established and supported by theoretical predictions. The suggested approach proved to be effective in discriminating between the thermal stabilities of Mo(CO)6 and W(CO)6. Therefore, an experimental verification of the predicted Sg–CO bond dissociation energy seems to be feasible by applying this technique. By investigating the effect of 104,105Mo beta-decay on the formation of 104,105Tc carbonyl complex, we estimated the lower reaction time limit for the metal carbonyl synthesis in the gas phase to be more than 100 ms. We examined further the influence of the wall material of the recoil chamber, the carrier gas composition, the gas flow rate, and the pressure on the production yield of 104Mo(CO)6, so that the future stability tests with Sg(CO)6 can be optimized accordingly.

Production and characterisation of monoclonal antibodies specific for bovine interleukin-4

Genetic immunisation is a simple method for producing polyclonal antibodies in mice. By this method, we produced antibodies against bovine interleukin-4 (BoIL-4). After a final injection with a recombinant BoIL-4 protein, nine stable hybridoma cell lines were established which secreted monoclonal antibodies (MAbs) against this cytokine. Specific binding of each of the MAbs to recombinant BoIL-4 produced by Escherichia coli, baculovirus, and Trypanosoma brucei was demonstrated in an indirect ELISA and/or in Western blotting. These MAbs recognise the same antigenic region localised in the first 47 amino acids of the mature protein. None of them was able to neutralise the biological activity of the BoIL-4 under the conditions tested but one allowed the detection of BoIL-4 by flow cytometry.

Positron bunching and electrostatic transport system for the production and emission of dense positronium clouds into vacuum

We describe a system designed to re-bunch positron pulses delivered by an accumulator supplied by a positron source and a Surko-trap. Positron pulses from the accumulator are magnetically guided in a 0.085 T field and are injected into a region free of magnetic fields through a μ -metal field terminator. Here positrons are temporally compressed, electrostatically guided and accelerated towards a porous silicon target for the production and emission of positronium into vacuum. Positrons are focused in a spot of less than 4 mm FWTM in bunches of ∼8 ns FWHM. Emission of positronium into the vacuum is shown by single shot positron annihilation lifetime spectroscopy.

Lateinamerika in der globalen Zirkulation von Expertise über den Umgang mit historischem Unrecht. Das Beispiel der Wahrheitskommissionen

Since the 1980s, the ways societies grapple with past human rights violations have become another area that is increasingly exposed to specialized knowledge production. Together with the profound changes in the dealing with the legacies of illegal or illegitimate exercise of power over the last decades, the expertise in the field not only expanded dramatically, but also became more diversified. The transitions from military dictatorships to democracies in South America in the 1980’s marked the historical beginning of this new era of coming to terms with the past, conceptualized in the following decade paradigmatically in the field of “transitional justice”. The subcontinent remained a central site in the global production and circulation of this knowledge, not least in regard to the two major innovations in societies’ arsenal of means of dealing with the past and their increasing conventionalization: the internationalization and transnationalization of the criminal prosecution of gross human rights violations and the truth commissions. Focusing on the expertise about truth commissions, the article aims to reconstruct and to analyze the role of Latin American experiences and actors in the remarkable global career of a key instrument in confronting past atrocities