From subduction to collision. a combined metamorphic, structural and geochronological study of polymetamorphic metasediments at the NE edge of the Lepontine dome (Swiss Central Alps)

This study analyses the tectono-metamorphic evolution of metasedimentary units belonging to the Valaisan and adjacent European domains at the north-eastern border of the Lepontine dome (Central Alps). The investigated area is characterized by a remarkable metamorphic gradient ranging from subduction-related HP/LT metamorphism in the NE to collision-related Barrovian overprint in the SW. Detailed structural fieldwork and petrological investigations including Raman spectroscopy of carbonaceous matter were carried out in order to reconstruct the tectono-metamorphic evolution on a larger scale. Furthermore, new 40Ar/39Ar dating of white mica and biotite reveal the timing of both subductionrelated high-pressure metamorphism and collision-related Barrovian overprint. The combination of all these investigations allows for deciphering a complete P-T-d-t path (pressure, temperature, deformation and time) of an area that occupies a key position in the Alpine orogenic belt for understanding the transition from subduction to collision. This study documents for the first time that relics of Fe-Mg carpholite indicating blueschist facies conditions occur also within metasedimentary units that are part of the north-eastern Lepontine dome where, so far, exclusively Barrovian assemblages were found. They occur in metasediments from both the Valaisan domain (Grava and Tomül nappes) and parts of the adjacent European domain (Peiden slices and Piz Terri-Lunschania unit). These high-pressure units were subsequently overprinted by a thermal event, as is documented by the growth of new minerals typical for Barrovian metamorphism. The investigated metasediments provide clear evidence for a bimodal P-T path in the north-eastern Lepontine dome characterized by the following polyphase metamorphic evolution: (1) Subductionrelated syn-D1 (Safien phase) HP/LT metamorphism under blueschist facies conditions (350-400 °C and 1.2-1.4 GPa) was established at 42-40 Ma, as revealed by 40Ar/39Ar dating of white mica associated with Fe-Mg carpholite; the early high-pressure event was followed by “cold” isothermal (or cooling) decompression during D2 nappe-stacking (Ferrera phase) for which an age of 36-33 Ma is inferred based on 40 Ar/39Ar dating of white mica replacing Fe-Mg carpholite. (2) Early collision-related greenschist facies overprint (350-425 °C) post-dating substantial decompression and associated D2 deformation was established at 32-29 Ma and affected both HP and LP metasediments. This metamorphic event clearly predates D3 deformation (Domleschg phase, ~25 Ma) as is evidenced by folded isotemperature contours. (3) Collision-related Barrovian overprint (500-590 °C and 0.5-0.8 GPa) represents a second and considerably younger (post 20 Ma) “isobaric” heating pulse only preserved in the SW part of the investigated area. Hence amphibolite facies metamorphism representing the mature stage of a colliding orogen is clearly separated by D2 and D3 deformations, as well as by an intervening greenschist facies event, from the D1 high-pressure stage. Amphibolite facies overprint occurred before and/or during the initial stages of D4 (Chièra phase), representing a second nappe-refolding event. This investigation revealed a significant time gap in the order of some 20 Ma between subductionrelated HP/LT metamorphism and collision-related MP/MT Barrovian overprint. This supports the notion of a polymetamorphic evolution associated with a bimodal P-T path. The results of this study argue that heat release from radioactive decay of vast amounts of accreted continental-derived basement nappes may play an important role in contributing much to heat production needed for amphibolite facies Barrow-type overprint. Based on field evidence, we conclude that heat transfer in the north-eastern Lepontine was essentially conductive during the latest stages of the thermal evolution

Correction of metabolic acidosis improves thyroid and growth hormone axes in haemodialysis patients

Background. Chronic metabolic acidosis (CMA) in normal adults results in complex endocrine and metabolic alterations including growth hormone (GH) insensitivity, hypothyroidism, hyperglucocorticoidism, hypoalbuminaemia and loss of protein stores. Similar alterations occur in chronic renal failure, a prototypical state of CMA. We evaluated whether metabolic acidosis contributes to the endocrine and metabolic alterations characteristic of end-stage renal disease. Methods. We treated 14 chronic haemodialysis patients with daily oral Na-citrate for 4 weeks, yielding a steady-state pre-dialytic plasma bicarbonate concentration of 26.7 mmol/l, followed by 4 weeks of equimolar Na-chloride, yielding a steady-state pre-dialytic plasma bicarbonate of 20.2 mmol/l. Results. Blood pressure, body weight and dialysis adequacy were equivalent in the two protocols. Na-citrate treatment corrected CMA, improved GH insensitivity, increased and normalized plasma free T3 concentration, and improved plasma albumin. Correction of CMA had no significant effect on measured cytokines (interleukin-1β and -6, tumour necrosis factor-α) or acute phase reactants (C-reactive protein, serum amyloid A, α2-macroglobulin). Conclusion. CMA contributes to the derangements of the growth and thyroid hormone axes and to hypoalbuminaemia, but is not a modulator of systemic inflammation in dialysis patients. Correcting CMA may improve nutritional and metabolic parameters and thus lower morbidity and mortalit

Correction of metabolic acidosis improves thyroid and growth hormone axes in haemodialysis patients

Background. Chronic metabolic acidosis (CMA) in normal adults results in complex endocrine and metabolic alterations including growth hormone (GH) insensitivity, hypothyroidism, hyperglucocorticoidism, hypoalbuminaemia and loss of protein stores. Similar alterations occur in chronic renal failure, a prototypical state of CMA. We evaluated whether metabolic acidosis contributes to the endocrine and metabolic alterations characteristic of end-stage renal disease. Methods. We treated 14 chronic haemodialysis patients with daily oral Na-citrate for 4 weeks, yielding a steady-state pre-dialytic plasma bicarbonate concentration of 26.7 mmol/l, followed by 4 weeks of equimolar Na-chloride, yielding a steady-state pre-dialytic plasma bicarbonate of 20.2 mmol/l. Results. Blood pressure, body weight and dialysis adequacy were equivalent in the two protocols. Na-citrate treatment corrected CMA, improved GH insensitivity, increased and normalized plasma free T3 concentration, and improved plasma albumin. Correction of CMA had no significant effect on measured cytokines (interleukin-1β and -6, tumour necrosis factor-α) or acute phase reactants (C-reactive protein, serum amyloid A, α2-macroglobulin). Conclusion. CMA contributes to the derangements of the growth and thyroid hormone axes and to hypoalbuminaemia, but is not a modulator of systemic inflammation in dialysis patients. Correcting CMA may improve nutritional and metabolic parameters and thus lower morbidity and mortalit

From subduction to collision: Thermal overprint of HP/LT meta-sediments in the north-eastern Lepontine Dome (Swiss Alps) and consequences regarding the tectono-metamorphic evolution of the Alpine orogenic wedge

The Cenozoic-age metamorphic structure of the Alps consists of a throughgoing pressure-dominated belt (blueschists and eclogites) that strikes parallel to the orogen and was later truncated by two thermal domes characterised by Barrow-type metamorphism (Lepontine dome and Tauern window). This study documents for the first time that relics of Fe-Mg carpholite occur also within meta-sedimentary units that are part of the north-eastern Lepontine structural and metamorphic dome, where so far exclusively Barrovian assemblages were found. They occur in meta-sediments of both Valais Oceanderived Lower Penninic Bündnerschiefer and structurally lower Europe-derived Sub-Penninic cover nappes and slices. These high-pressure units were subsequently overprinted by a thermal event, as is documented by the growth of new minerals typical for Barrovian metamorphism. We present evidence for a two-stage metamorphic evolution in the northern part of the Lepontine dome: (1) Early subduction-related syn-D1 (Safien phase) HP/LT metamorphism under blueschist facies conditions (350-400°C and 1.2-1.4 GPa) was immediately followed by "cold” isothermal (or cooling) decompression during D2 nappe-stacking (Ferrera phase). (2) Collisionrelated Barrovian overprint (500-570°C and 0.5-0.8 GPa) postdates the D3 nappe-refolding event (Domleschg phase) and represents a late heating pulse, separated by D2 and D3 from the D1 high-pressure event. It occurred before and/or during the initial stages of D4 (Chiéra phase) representing a second nappe-refolding event. In discussing possible heat sources for the late Barrow-type heating pulse it is argued that heat release from radioactive decay of accreted material may play an important role in contributing much to heat production. Based on the field evidence, we conclude that heat transfer was essentially conductive during these latest stages of the thermal evolutio

3-D assessment of peak-metamorphic conditions by Raman spectroscopy of carbonaceous material: an example from the margin of the Lepontine dome (Swiss Central Alps)

This study monitors regional changes in the crystallinity of carbonaceous matter (CM) by applying Micro-Raman spectroscopy to a total of 214 metasediment samples (largely so-called Bündnerschiefer) dominantly metamorphosed under blueschist- to amphibolite-facies conditions. They were collected within the northeastern margin of the Lepontine dome and easterly adjacent areas of the Swiss Central Alps. Three-dimensional mapping of isotemperature contours in map and profile views shows that the isotemperature contours associated with the Miocene Barrow-type Lepontine metamorphic event cut across refolded nappe contacts, both along and across strike within the northeastern margin of the Lepontine dome and adjacent areas. Further to the northeast, the isotemperature contours reflect temperatures reached during the Late Eocene subduction-related blueschist-facies event and/or during subsequent near-isothermal decompression; these contours appear folded by younger, large-scale post-nappe-stacking folds. A substantial jump in the recorded maximum temperatures across the tectonic contact between the frontal Adula nappe complex and surrounding metasediments indicates that this contact accommodated differential tectonic movement of the Adula nappe with respect to the enveloping Bündnerschiefer after maximum temperatures were reached within the northern Adula nappe, i.e. after Late Eocene tim

Multistage Zeeman deceleration of metastable neon

A supersonic beam of metastable neon atoms has been decelerated by exploiting the interaction between the magnetic moment of the atoms and time-dependent inhomogeneous magnetic fields in a multistage Zeeman decelerator. Using 91 deceleration solenoids, the atoms were decelerated from an initial velocity of 580m/s to final velocities as low as 105m/s, corresponding to a removal of more than 95% of their initial kinetic energy. The phase-space distribution of the cold, decelerated atoms was characterized by time-of-flight and imaging measurements, from which a temperature of 10mK was obtained in the moving frame of the decelerated sample. In combination with particle-trajectory simulations, these measurements allowed the phase-space acceptance of the decelerator to be quantified. The degree of isotope separation that can be achieved by multistage Zeeman deceleration was also studied by performing experiments with pulse sequences generated for $^{20}$Ne and $^{22}$Ne.Comment: 16 pages, 15 figure

The GermOnline cross-species systems browser provides comprehensive information on genes and gene products relevant for sexual reproduction

We report a novel release of the GermOnline knowledgebase covering genes relevant for the cell cycle, gametogenesis and fertility. GermOnline was extended into a cross-species systems browser including information on DNA sequence annotation, gene expression and the function of gene products. The database covers eight model organisms and Homo sapiens, for which complete genome annotation data are available. The database is now built around a sophisticated genome browser (Ensembl), our own microarray information management and annotation system (MIMAS) used to extensively describe experimental data obtained with high-density oligonucleotide microarrays (GeneChips) and a comprehensive system for online editing of database entries (MediaWiki). The RNA data include results from classical microarrays as well as tiling arrays that yield information on RNA expression levels, transcript start sites and lengths as well as exon composition. Members of the research community are solicited to help GermOnline curators keep database entries on genes and gene products complete and accurate. The database is accessible at

Ontology for Future-robust Product Portfolio Evolution: A Basis for the Development of Models and Methods

The future-robust evolution of product portfolios is a key challenge for manufacturing companies. It requires the integration of strategic product planning and the understanding that products are developed in generations based on references following the SGE - System Generation Engineering theory. There is, though, a lack of consistent terminology that unites these topics and makes their concepts consistent. Their terms are used differently across industries, institutions, and companies. The resulting miscommunication leads to a loss of efficiency. Hence, a structured, interrelated terminology is needed. The paper contributes an ontology that delivers a unifying basis for the development of models and methods