Theta functions and arithmetic quotients of loop groups

In this paper we observe that isomorphism classes of certain metrized vector bundles over P^1-{0,infinity} can be parameterized by arithmetic quotients of loop groups. We construct an asymptotic version of theta functions, which are defined on these quotients. Then we prove the convergence and extend the theta functions to loop symplectic groups. We interpret them as sections of line bundles over an infinite dimensional torus, discuss the relations with loop Heisenberg groups, and give an asymptotic multiplication formula.Comment: 16 page

Implications of subduction rehydration for earth's deep water cycle

The “standard model” for the genesis of the oceans is that they are exhalations from Earth’s deep interior continually rinsed through surface rocks by the global hydrologic cycle. No general consensus exists, however, on the water distribution within the deeper mantle of the Earth. Recently Dixon et al. [2002] estimated water concentrations for some of the major mantle components and concluded that the most primitive (FOZO) are significantly wetter than the recycling associated EM or HIMU mantle components and the even drier depleted mantle source that melts to form MORB. These findings are in striking agreement with the results of numerical modeling of the global water cycle that are presented here. We find that the Dixon et al. [2002] results are consistent with a global water cycle model in which the oceans have formed by efficient outgassing of the mantle. Present-day depleted mantle will contain a small volume fraction of more primitive wet mantle in addition to drier recycling related enriched components. This scenario is consis-tent with the observation that hotspots with a FOZO-component in their source will make wetter basalts than hotspots whose mantle sources contain a larger fraction of EM and HIMU components

Autonomy and Paternalism

I wish to determine when one is justified in paternalistic interferences that override a subject’s autonomy. In order to lay the groundwork for discussing paternalistic interferences with autonomous decisions, I first consider different conceptions of autonomy, welfare, and paternalism, and determine which I mean to use. In particular, I proceed with Dworkin’s characterization of autonomy as a combination of authenticity and self-determination; Nussbaum’s capabilities theory in order to determine welfare; and a definition of paternalism as being an interference with a subject’s liberty or autonomy that is motivated exclusively by consideration for that subject’s own good or welfare. Once I have working definitions for autonomy, welfare, and paternalism, I consider arguments justifying paternalistic interferences. Because I especially wish to determine when paternalistic interferences that conflict with a subject’s autonomous decision are justified, I begin with Scoccia’s arguments for using hypothetical consent — which is based on what would maximize the subject’s welfare — to justify paternalistic acts. Using Scoccia’s argument, I consider a few cases in which concerns for welfare may justify paternalistic acts overriding the subject’s autonomy. However, hypothetical consent does not go very far in justifying paternalistic acts. Therefore, I also consider arguments justifying paternalism in cases where the subject is not necessarily fully autonomous when making or acting upon a decision. For example, Carter argues that paternalistic acts are justified if autonomy has been waived through prior or subsequent consent. Additionally, I look at justifying paternalism when the subject’s autonomy is compromised through involuntariness or incompetence

Mid-Atlantic expedition 2003/2004 : research vessel Meteor, cruise No. M60 ; 11. November 2003 – 15. April 2004

Die Meteor-Reise 60 besteht aus 5 Fahrtabschnitten im subtropischen Wirbel des Nordatlantiks von den Azoren bzw. Madeira bis zum tropischen Westatlantik. Fahrtabschnitt 1 konzentriert sich auf die Ökologie und Biogeochemie von sogenannten „Seamounts“ im östlichen Atlantik im Rahmen eines EU-Projektes; Fahrtabschnitt 2 umfasst, in Zusammenarbeit mit französischen Kollegen, detailierte seismische und geophysikalische Untersuchungen eines aktiven Segments des Mittelatlantischen Rückens; Fahrtabschnitt 3 ist eine multidisziplinäre (geologisch, biologisch und chemisch) Untersuchung über die Auswirkungen der hydrothermalen Zirkulation am Mittelatlantischen Rücken im Rahmen eines DFG-Schwerpunkt-programms; Fahrtabschnitt 4 ist einer physikalisch-ozeanographische Studie der langfristigen Variation der thermohalien Zirkulation in westlichen Becken des Atlantiks im Kontext des BMBF-CLIVAR programms gewidmet; und Fahrtabschnitt 5 schließlich, ist eine multidisziplinäre (chemisch/biologisch) Untersuchung über die CO2-Aufnahme und die biologische Pumpe in der Wassersäule des nordatlantischen Subtropenwirbels (DFG-Sonderforschungsbereich 460). Der erste Fahrtabschnitt der Reise M 60 dient der physikalischen, biogeochemischen und biologischen Probengewinnung im Rahmen des EU- Projektes OASIS (OceAnic Seamounts: an Integrated Study). OASIS ist ein interdisziplinäres Projekt mit 9 Partnern aus 5 europäischen Ländern und untersucht die funktionale Charakteristik von Seamount-Ökosystemen. Basierend auf 2 Fallstudien werden die Prozesse, die Seamount-Ökosysteme charakterisieren, und ihre Einflüsse auf den umgebenden Ozean beschrieben. Die wissenschaftlichen Ergebnisse, zusammengeführt in einem konzeptionellen Ökosystemmodell, werden Ausgangsbasis für die Entwicklung von generellen und ortspezifischen Managementplänen sein. Das primäre Ziel von OASIS, eine holistische Erfassung von Seamount-Ökosystemen, wird durch die Integration folgender Sachgebiete erreicht: a) Identifikation und Beschreibung der physikalischen Einflußkräfte auf Seamount-Ökosysteme b) Erfassung der Herkunft, Qualität und Dynamik partikulärer organischer Substanz in der Wassersäule und an der Sedimentoberfläche c) Beschreibung von Aspekten der Biodiversität und Ökologie von Seamount-Lebensgemeinschaften und Erfassung ihrer Dynamik und Produktionsmechanismen d) Modellierung der trophischen Ökologie von Seamount-Ökosystemen e) Anwendung der wissenschaftlichen Ergebnisse auf den Naturschutz. Ein weiteres Ziel der Fahrt ist die Erprobung eines neu entwickelten Drucklabors zur Untersuchung von Tiefseeorganismen unter in situ-Druckbdingenungen von bis zu 500 bar.The Meteor 60 expedition is comprised of 5 legs covering the sub-tropical gyre of the North Atlantic from the Azores and Madeira to the tropical western Atlantic. Leg 1 focuses on the ecology and biogeochemistry of seamounts in the eastern Atlantic in the context of an EU program; Leg 2 comprises a detailed seismic and geophysical investigation of a propagating ridge segment at the Mid-Atlantic Ridge in cooperation with French scientists; Leg 3 is a multidisciplinary (geological, biological and chemical) investigation of the effects of hydrothermal circulation at the Mid-Atlantic ridge in support of a DFG Special Priority Program; Leg 4 is a physical oceanographic study of long-term variation of the thermohaline circulation in the western basin of the Atlantic in the context of the BMBF-CLIVAR program; and Leg 5 is a multidisciplinary (chemical/biological) investigation of CO2 uptake and the biological pump in the water column of the North Atlantic sub-tropical gyre (DFG Special Research Area 460). The first leg of cruise M 60 aims at physical, biogeochemical and biological sampling in the framework of the EU project OASIS (OceAnic Seamounts: an Integrated Study). OASIS is an interdisciplinary project and comprises 9 partners from 5 European countries. The project studies the functional characteristics of seamount ecosystems. Based on two case studies, OASIS will yield an advanced mechanistic understanding of the processes characterizing seamount ecosystems, and their influence on the surrounding ocean. The scientific knowledge gained, condensed in a conceptual ecosystem model, will be applied to outline a model management plan as well as site-specific management plans for the seamounts investigated The primary goal of OASIS, to provide a holistic, integrated assessment of seamount ecology, will be achieved by addressing the following main objectives: a) To identify and describe the physical forcing mechanisms effecting seamount systems. b) To assess the origin, quality and dynamics of particulate organic material within the water column and surface sediment at seamounts. c) To describe aspects of the biodiversity and the ecology of seamount biota, to assess their dynamics and the maintenance of their production. d) Modelling the trophic ecology of seamount ecosystems. e) Application of scientific knowledge to practical conservation. A further goal of the cruise will be to test a newly developed hyperbaric laboratory which is designed to study deep-sea organisms under in situ pressure

Delivery suite assessment unit: auditing innovation in maternity triage

yesA Delivery Suite Assessment Unit (DSAU) has been established at a large Northern teaching hospital. This was as a recommendation of ASQUAM (achieving sustainable quality in maternity) to reduce antenatal admissions to delivery suite and provide a more appropriate environment for women attending for antenatal or labour assessment. The DSAU has also provided an effective teaching environment where skills such as effective telephone triage, diagnosis of labour and care of women with pre-labour spontaneous rupture of membranes (SROM) have been developed by junior staff. The first twelve months' audit results indicate that the establishment of the DSAU has been successful in reducing antenatal admissions to delivery suite by increasing the transfers of clients home, rather than to the antenatal wards. This may reflect the confidence of the highly skilled midwives working in this environment and the confidence women feel about their ability to obtain prompt and accurate advice over the telephone

On subducting slab entrainment of buoyant asthenosphere

Laboratory and numerical experiments and boundary layer analysis of the entrainment of buoyant asthenosphere by subducting oceanic lithosphere implies that slab entrainment is likely to be relatively inefficient at removing a buoyant and lower viscosity asthenosphere layer. Asthenosphere would instead be mostly removed by accretion into and eventual subduction of the overlying oceanic lithosphere. The lower (hot) side of a subducting slab entrains by the formation of a ∼10–30 km-thick downdragged layer, whose thickness depends upon the subduction rate and the density contrast and viscosity of the asthenosphere, while the upper (cold) side of the slab may entrain as much by thermal 'freezing' onto the slab as by mechanical downdragging. This analysis also implies that proper treatment of slab entrainment in future numerical mantle flow experiments will require the resolution of ∼10–30 km-thick entrainment boundary layers

The Electrical Properties of a 2D Conductive Zone underneath the Juan de Fuca Ridge

Vertical gradient electromagnetic sounding (VGS) on the Endeavour segment of Juan de Fuca mid‐ocean ridge reveals the presence of a 2D ridge‐parallel, conductivity anomaly. If the anomaly is caused mainly by melt in a conventional upper mantle upwelling zone alone, then the conductivity of the zone is about 0.6 S/m. The corresponding Archie's law melt fraction exceeds 0.10. A significantly lower melt fraction requires a sheet‐like, well interconnected melt. Upwelling zone conductivity can be reduced by a third if the anomaly is broadened and a crustal conductor is added to the model

Crustal structure of the propagating TAMMAR ridge segment on the Mid-Atlantic Ridge, 21.5°N

Active ridge propagation frequently occurs along spreading ridges and profoundly affects ridge crest segmentation over time. The mechanisms controlling ridge propagation, however, are poorly understood. At the slow spreading Mid-Atlantic Ridge at 21.5°N a seismic refraction and wide-angle reflection profile surveyed the crustal structure along a segment controlled by rapid ridge propagation. Tomographic traveltime inversion of seismic data suggests that the crustal structure along the ridge axis is controlled by melt supply; thus, crust is thickest, 8 km, at the domed segment center and decreases in thickness toward both segment ends. However, thicker crust is formed in the direction of ridge propagation, suggesting that melt is preferentially transferred toward the propagating ridge tip. Further, while seismic layer 2 remains constant along axis, seismic layer 3 shows profound changes in thickness, governing variations in total crustal thickness. This feature supports mantle upwelling at the segment center. Thus, fluid basaltic melt is redistributed easily laterally, while more viscose gabbroic melt tends to crystallize and accrete nearer to the locus of melt supply. The onset of propagation seems to have coincided with the formation of thicker crust, suggesting that propagation initiation might be due to changes in the melt supply. After a rapid initiation a continuous process of propagation was established. The propagation rate seems to be controlled by the amount of magma that reaches the segment ends. The strength of upwelling may govern the evolution of ridge segments and hence ultimately controls the propagation length