Stability and isotopic dating of monazite and allanite in partially molten rocks: examples from the Central Alps

We investigated the stability of monazite and allanite as a function of bulk rock composition within several types of Tertiary Alpine anatexites, characterized by different compositions and melting reactions, but similar P-T conditions of melting. The investigated rocks consist of: (1) orthogneisses in which the melting reaction was triggered by water infiltration from the Bergell pluton; (2) anatectic tonalites, which were affected by water-assisted melting; and (3) metapelitic migmatites, which underwent muscovite dehydration melting. The studied anatexites cover a large range of Ca contents and water activities during partial melting, and allow an assessment of how much these parameters affect the stability of accessory phases. The different melting reactions that affected these rocks generated different water activities during the melt-present stage; they were highest in the water-saturated, contact metamorphic anatexites, and lowest in the metapelitic anatexites that underwent dehydration melting. These differences go together with different accessory phases within the migmatites. Whereas metapelitic anatexites only contain monazite, anatexites derived from tonalitic and granodioritic protoliths mainly contain allanite. This is consistent with observations made on Tertiary Alpine anatexites, suggesting that the growth of specific accessory phases is determined by the water activity and Ca content during melting. We measured single-grain monazite U/Pb isotope ages. One grain has relics of old cores, which have also been detected in Y-zonation patterns of the monazite. The data of unzoned monazites indicate partial melting in the Southern Steep Belt between 30.78 ± 0.14 and 28.10 ± 0.28M

Advancing surgical instrument safety: A screen of oxidative and alkaline prion decontaminants using real-time quaking-induced conversion with prion-coated steel beads as surgical instrument mimetic

Iatrogenic transmission of prions, the infectious agents of fatal Creutzfeldt-Jakob disease, through inefficiently decontaminated medical instruments remains a critical issue. Harsh chemical treatments are effective, but not suited for routine reprocessing of reusable surgical instruments in medical cleaning and disinfection processes due to material incompatibilities. The identification of mild detergents with activity against prions is therefore of high interest but laborious due to the low throughput of traditional assays measuring prion infectivity. Here, we report the establishment of TESSA (sTainlESs steel-bead Seed Amplification assay), a modified real-time quaking induced cyclic amplification (RT-QuIC) assay that explores the propagation activity of prions with stainless steel beads. TESSA was applied for the screening of about 70 different commercially available and novel formulations and conditions for their prion inactivation efficacy. One hypochlorite-based formulation, two commercially available alkaline formulations and a manual alkaline pre-cleaner were found to be highly effective in inactivating prions under conditions simulating automated washer-disinfector cleaning processes. The efficacy of these formulations was confirmed in vivo in a murine prion infectivity bioassay, yielding a reduction of the prion titer for bead surface adsorbed prions below detectability. Our data suggest that TESSA represents an effective method for a rapid screening of prion-inactivating detergents, and that alkaline and oxidative formulations are promising in reducing the risk of potential iatrogenic prion transmission through insufficiently decontaminated instrument surfaces

A screen of alkaline and oxidative formulations for their inactivation efficacy of metal surface adsorbed prions using a steel-bead seed amplification assay

Iatrogenic transmission of prions, the infectious agents of fatal Creutzfeldt-Jakob disease, through inefficiently decontaminated medical instruments remains a critical issue. Harsh chemical treatments are effective, but not suited for routine reprocessing of reusable surgical instruments in medical cleaning and disinfection processes due to material incompatibilities. The identification of mild detergents with activity against prions is therefore of high interest but laborious due to the low throughput of traditional assays measuring prion infectivity. Here, we report the development of TESSA (sTainlESs steel-beadSeedAmplification assay), a prion seed amplification assay that explores the propagation activity of prions with stainless steel beads. TESSA was applied for the screening of about 70 different commercially available and novel formulations and conditions for their prion inactivation efficacy. One hypochlorite-based formulation, two commercially available alkaline formulations and a manual alkaline pre-cleaner were found to be highly effective in inactivating prions under conditions simulating automated washer-disinfector cleaning processes. The efficacy of these formulations was confirmedin vivoin a murine prion infectivity bioassay, yielding a reduction of the prion titer for the bead surface adsorbed prions below detectability. Our data suggest that TESSA represents an effective method for a rapid screening of prion-inactivating detergents, and that alkaline and oxidative formulations are promising in reducing the risk of potential iatrogenic prion transmission through insufficiently decontaminated instrument surfaces

Axiomatic Choice Theory Traveling between Mathematical Formalism, Normative Choice Rules and Psychological Measurement, 1944-1956

The following analysis is meant to contribute to a history of rational choice theory. More specifically, I provide a multi-layered account of rational choice theory in terms of its biography as a scientific object. I argue that its axiomatic version, choice theory traveled between different research sites, specified within the context of different mathematical formalisms and occupying different epistemic functions; it was being applied to prescribe rules of proper behavior, as representation of behavioral hypotheses, and as measurement device to capture individual values. New modifications of what I call 'axiomatic choice theory' did not fully replace old versions of it, which prevents the reconstruction of its 'travels' as a continuous process and acknowledges the different versions of axiomatic choice theory that are currently used in the social sciences, particularly in economics. Furthermore, by revealing the diversity of its manifestations within the context of social networks and within particular research sites, the account of axiomatic choice theory developed here will ultimately contributes to an explanation of the disunity and confusion surrounding current debates about rational choice theory and allows for providing a more nuanced picture of its nature and scope. Jacob Marschak's professional development is used as a guide through this history of axiomatic choice theory to illustrate its journey

Stability and isotopic dating of monazite and allanite in partially molten rocks: examples from the Central Alps

We investigated the stability of monazite and allanite as a function of bulk rock composition within several types of Tertiary Alpine anatexites, characterized by different compositions and melting reactions, but similar P-T conditions of melting. The investigated rocks consist of: (1) orthogneisses in which the melting reaction was triggered by water infiltration from the Bergell pluton; (2) anatectic tonalites, which were affected by water-assisted melting; and (3) metapelitic migmatites, which underwent muscovite dehydration melting. The studied anatexites cover a large range of Ca contents and water activities during partial melting, and allow an assessment of how much these parameters affect the stability of accessory phases. The different melting reactions that affected these rocks generated different water activities during the melt-present stage; they were highest in the water-saturated, contact metamorphic anatexites, and lowest in the metapelitic anatexites that underwent dehydration melting. These differences go together with different accessory phases within the migmatites. Whereas metapelitic anatexites only contain monazite, anatexites derived from tonalitic and granodioritic protoliths mainly contain allanite. This is consistent with observations made on Tertiary Alpine anatexites, suggesting that the growth of specific accessory phases is determined by the water activity and Ca content during melting

Vorausschauende Steuerung von aktiven Prothesenfüßen

Zur besseren Bodenanpassung beim Gehen und aufgrund der ungelösten Problematik, Stolperunfälle mit Beinprothesen verhindern zu können, gibt es einen Bedarf zur Entwicklung eines Systems mit vorausschauender Anpassung der künstlichen Gliedmaße an den Untergrund. Es wird ein optisch messendes System beschrieben, das kontinuierlich während der aktuellen Standphase räumlich den Untergrund im Zielbereich des kommenden Schrittes erfasst. Aus den gewonnenen dreidimensionalen Messdaten werden Körper oder Umgebungsstrukturen wie Treppen oder Rampen ermittelt. Die Prothesensteuerung wählt auf Basis dieser Auswertung die optimale Einstellung der Prothesengelenke zur Begehung des Terrains im folgenden Gangzyklus

Adaptives Steuerungs- und Regelungssystem fuer Prothesen mit willkuerlicher Steuerung

DE 102009056466 A1 UPAB: 20110621 NOVELTY - The method involves measuring muscle activating signals. The status information is measured at actual movement condition of the prosthesis carrier for determining the current movement condition. The voluntary signal is determined with the current movement condition for evaluating the actuating elements of the prosthesis. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (1) an adaptive controlling and regulating system with a processor; and (2) prosthesis with a prosthesis carrier. USE - Method for adaptive controlling and regulating the prosthesis with voluntary control (all claimed) for a base system (from drawings). ADVANTAGE - The method involves measuring muscle activating signals, where the status information is measured at actual movement condition of the prosthesis carrier, thus ensures an improved adaptive controlling and regulating method