Gravitational Waves from Axisymmetric, Rotational Stellar Core Collapse

We have carried out an extensive set of two-dimensional, axisymmetric, purely-hydrodynamic calculations of rotational stellar core collapse with a realistic, finite-temperature nuclear equation of state and realistic massive star progenitor models. For each of the total number of 72 different simulations we performed, the gravitational wave signature was extracted via the quadrupole formula in the slow-motion, weak-field approximation. We investigate the consequences of variation in the initial ratio of rotational kinetic energy to gravitational potential energy and in the initial degree of differential rotation. Furthermore, we include in our model suite progenitors from recent evolutionary calculations that take into account the effects of rotation and magnetic torques. For each model, we calculate gravitational radiation wave forms, characteristic wave strain spectra, energy spectra, final rotational profiles, and total radiated energy. In addition, we compare our model signals with the anticipated sensitivities of the 1st- and 2nd-generation LIGO detectors coming on line. We find that most of our models are detectable by LIGO from anywhere in the Milky Way.Comment: 13 pages, 22 figures, accepted for publication in ApJ (v600, Jan. 2004). Revised version: Corrected typos and minor mistakes in text and references. Minor additions to the text according to the referee's suggestions, conclusions unchange

Mineralisation patterns in the subchondral bone plate of the humeral head

Purpose: Pathologic changes of the glenohumeral joint, like a long-standing overloading or an accident often lead to severe glenohumeral osteoarthritis, and a glenohumeral joint replacement could be necessary. Joint instability and glenoid loosening are the most common post-operative complications, which can be caused by eccentric loading of the glenoid, if the humeral head is malcentered. If these malcentered cases could be identified pre-operatively, the pathologic position of the humeral head could be fixed intra-operatively and complication may be prevented. Computed tomography osteoabsorptiometry (CT-OAM) is a useful method to determine the distribution of mineralisation in the subchondral bone as a marker for the long-term loading history of a joint. The objective of this study was to gain information about the mineralisation distribution in the subchondral bone plate of the humeral head. Methods: By the use of CT-OAM, the distribution of the subchondral mineralisation of 69 humeral heads was investigated and groups of mineralisation patterns were built. To evaluate if differences in age exist, the mean values of the two groups were compared using t test. Results: 49 humeral heads (71% of 69 specimens) showed bicentric subchondral mineralisation patterns with ventral and dorsal maxima, 20 humeral heads (29% of 69 specimens) could be classified as monocentric with a centro-dorsal maximum. We found no statistical significant difference between the age of the monocentric and the bicentric group on a significance level of 95%. Conclusion: We could show that stress distribution at the humeral head is typically bicentric with a ventral and dorsal maximum. However, other mineralisation patterns may occur under pathologic circumstances. The pre-operative identification of such cases by the use of CT-OAM could help to improve the post-operative results in shoulder surger

Prognosen auf Agrarmärkten: Prediction Markets - eine innovative Prognosemethode auch für die Landwirtschaft?

Seit geraumer Zeit haben "Prediction Markets", auch "Prognosemärkte" oder "InformationsMärkte" genannt, ihre Nützlichkeit bei der Prognose von Wahlergebnissen, der Vorhersage von Absatzzahlen, von Abschlussterminen von Entwicklungsprojekten und vielen anderen Ereignissen und Entwicklungen bewiesen. Die Vorhersage zukünftiger Entwicklungen in der Land und Ernährungswirtschaft hat mit der zunehmenden Integration der EUMärkte in die Weltmärkte zugenommen. Nach einer kurzen Darstellung des Vorhersagebedarfs im Agribusiness wird anschließend das Funktionsprinzip eines "Prediction Markets" dargestellt und am Beispiel eines Prototyps zur Vorhersage von Milchquotenpreisen in Deutschland veranschaulicht. Die Prognose von Milchquotenpreisen ist insbesondere vor dem Hintergrund der spezifischen Handelsregelungen (Preiskorridor) für die Akteure auf diesem Markt von Bedeutung. Die theoretischen Hintergründe der Informationsaggregationsleistung von werden neben den Voraussetzungen und offenen Problemen von "Prediction Markets" im Ablauf noch kurz dargestellt und diskutiert.Agribusiness, Research Methods/ Statistical Methods, Prognosemärkte, Prognosemethoden, Agribusiness,

Potential CO2-production in aerobic conditions from a Siberian tundra environment

Soil respiration was analysed from different soil profiles of an arctic tundra environment (Samoylov Island, Lena Delta, East Siberia) during field studies in 1998 and 1999. Samples from discrete soil layers (0-47 cm), from the soil surface down to the permafrost table, were incubated and analysed for CO_2-evolution at different temperatures, related to ambient values (0°C to 20°C) in a dynamic chamber system. The soil investigated was located in a low-centre polygon on a poorly drained peat terrace and determined as a Glacic Aquiturbel. Soil respiration data from the individual layers of this location were combined with soil temperature measurements of a comparable tundra environment near Tiksi. These data were split into discrete intervals of 5°C which were regarded as intervals for different levels of soil microbial activity. Time spans for these temperature ranges were calculated and used as a base for further calculations of potential seasonal CO_2-emissions. Changing patterns of soil respiration could be related to varying substrate conditions and effects of physical factors, especially freezing and thawing. They are regarded as important factors controlling CO_2-flux from tundra soils. High levels of CO_2-evolution can be attributed to soil layers where high amounts of organic matter are available, oxygen penetrates through soil pores and elevated temperatures above 0°C maintain metabolic processes

Sustainable and healthy diets: trade-offs and synergies : final scientific report

This project aimed at analysing trade-offs and synergies between healthy nutrition and sustainable food systems. First, we identified nutritional patters of the Swiss population based on representative consumption data. The health impacts of these nutritional patterns were then analysed based on a review of the scientific literature on health impacts of food commodities and diets and by calculating the Alternate Healthy Eating Index (AHEI), the Mediterranean Diet Score (MDS) and Disability Adjusted Life Years (DALYs) of the nutritional patterns. Second, we comprehensively analysed health, environmental, social and economic impacts and related trade-offs and synergies for a number of future scenarios of Swiss agricultural production and food consumption. For this, we used a modelling approach, linking three different models: a global mass flow model, a system dynamics model and an environmentally extended input-output model. We modelled ten different scenarios for the Swiss Food Sector in 2050. These scenarios were either developed in a participatory process during a series of interviews and group discussions with different groups of stakeholders or optimised environmental impacts while at the same time complying with different nutritional and agronomic restrictions. Three main scenarios were analysed with all three models in detail. Among these main scenarios was the SwissFoodPyramid2050 Scenario, which assumes a widespread implementation of the nutritional recommendations according to the Swiss Food Pyramid. The FeedNoFood2050 Scenario assumes an improved use of agricultural land by feeding only grass and by-products to livestock, which was not competing with direct human nutrition, i.e. did not require arable land (neither in Switzerland nor abroad). The third scenario was a reference scenario, which assumes no changes in diets until 2050 and which was used to compare the two alternative scenarios. The other scenarios were targeted at specific questions such as minimizing greenhouse gases. Our results illustrate two visions of how healthy diets and sustainable food systems could look like. Both the SwissFoodPyramid2050 and the FeedNoFood2005 scenarios would require similar dietary changes, such as a reduction of meat consumption and an increase of consumption of pulses. However, there are also fundamental differences between the diets in the two alternative scenarios, e.g. regarding the type of meat consumed. These differences can be interpreted as trade-offs which result from agronomic boundary conditions such as the coupled production of milk and meat, the availability of natural resources, such as grassland and co-products of food processing and health aspects of Swiss diets. Of primary importance in this respect was the use of permanent grasslands and the co-production of veal and beef with dairy production due to environmental reasons and reasons for optimally utilizing available resources. This means, if permanent grassland should be maintained as an ecosystem, dairy production would provide the basis for animal proteins. Thus, while in the FeedNoFood2050 Scenario veal and rather low-quality beef from dairy cows is consumed instead of meat from monogastrics, the SwissFoodPyramid2050 Scenario would result in a higher amount of meat from monogastrics. Our results imply that there is a lack of a comprehensive food systems view in the current discussion on healthy and sustainable diets. Stronger coherence between health, food and agricultural policy is needed to account for systemic boundary conditions and thus to allow for minimising trade-offs and maximise synergies. Current agricultural policies fail to address the health perspective. Financial support for meat and sugar producers, which lead to lower prices for those products and ultimately to a higher consumption than without these policies, are two obvious examples. Yet, comprehensive visions such as the SwissFoodPyramid scenario, the FeedNoFood Scenario or optimised scenarios would require an even more complex policy mix of incentives, regulations and information campaigns. This would probably need an adaptation of the current institutional setting and division of competences between the Federal Offices for Agriculture (FOAG) and for the Environment (FOEN), the State Secretariat for Economic Affairs (SECO) and the Federal Food Safety and Veterinary Office (FSVO). A commonly shared vision, including specific goals with respect to how the Swiss food system should look like, is urgently needed. Developing such a vision needs to involve all operators and stakeholders of the food system, as our results imply that more sustainable and healthy diets do not necessarily go along with financial benefits of both producers and consumers. These trade-offs and the knowledge of behavioural economics need to be considered for designing settings which create mutual benefits for operators in the food sector. For instance, neither the majority of consumers, food industry nor agricultural producers can be expected to respond altruistically as an entire sector in the long term. Therefore, policy needs to set financial incentives for internalising environmental and social externalities in order to push and pull the food system towards sustainability. Furthermore, it is crucial to account for agronomic boundary conditions and systemic aspects, such as the role of ruminants in utilizing grasslands and the unavoidable link of milk and meat production

In the human malaria parasite Plasmodium falciparum,polyamines are synthesized by a bifunctional ornithine decarboxylase, S-adenosylmethionine decarboxylase

The polyamines putrescine, spermidine, and spermine are crucial for cell differentiation and proliferation. Interference with polyamine biosynthesis by inhibition of the rate-limiting enzymes ornithine decarboxylase (ODC) andS-adenosylmethionine decarboxylase (AdoMetDC) has been discussed as a potential chemotherapy of cancer and parasitic infections. Usually both enzymes are individually transcribed and highly regulated as monofunctional proteins. We have isolated a cDNA from the malaria parasite Plasmodium falciparumthat encodes both proteins on a single open reading frame, with the AdoMetDC domain in the N-terminal region connected to a C-terminal ODC domain by a hinge region. The predicted molecular mass of the entire transcript is 166 kDa. The ODC/AdoMetDC coding region was subcloned into the expression vector pASK IBA3 and transformed into the AdoMetDC- and ODC-deficient Escherichia coli cell line EWH331. The resulting recombinant protein exhibited both AdoMetDC and ODC activity and co-eluted after gel filtration on Superdex S-200 at ~333 kDa, which is in good agreement with the molecular mass of ~326 kDa determined for the native protein from isolated P. falciparum. SDS-polyacrylamide gel electrophoresis analysis of the recombinant ODC/AdoMetDC revealed a heterotetrameric structure of the active enzyme indicating processing of the AdoMetDC domain. The data presented describe the occurrence of a unique bifunctional ODC/AdoMetDC in P. falciparum, an organization which is possibly exploitable for the design of new antimalarial drugs

'MOHAWK' : a 4000-fiber positioner for DESpec

We present a concept for a 4000-fibre positioner for DESpec, based on the Echidna 'tilting spine' technology. The DESpec focal plane is 450mm across and curved, and the required pitch is ~6.75mm. The size, number of fibers and curvature are all comparable with various concept studies for similar instruments already undertaken at the AAO, but present new challenges in combination. A simple, low-cost, and highly modular design is presented, consisting of identical modules populated by identical spines. No show-stopping issues in accommodating either the curvature or the smaller pitch have been identified, and the actuators consist largely of off-the-shelf components. The actuators have been prototyped at AAO, and allow reconfiguration times of ~15s to reach position errors 7 microns or less. Straightforward designs for metrology, acquisition, and guiding are also proposed. The throughput losses of the entire positioner system are estimated to be ~15%, of which 6.3% is attributable to the tilting-spine technology.Comment: 10 pages, to appear in Proc. SPIE 844

'MOHAWK': A 4000-fiber positioner for DESpec

We present a concept for a 4000-fibre positioner for DESpec, based on the Echidna 'tilting spine' technology. The DESpec focal plane is 450mm across and curved, and the required pitch is ∼6.75mm. The size, number of fibers and curvature are all compara