Spatial interference from well-separated condensates

We use magnetic levitation and a variable-separation dual optical plug to obtain clear spatial interference between two condensates axially separated by up to 0.25 mm -- the largest separation observed with this kind of interferometer. Clear planar fringes are observed using standard (i.e. non-tomographic) resonant absorption imaging. The effect of a weak inverted parabola potential on fringe separation is observed and agrees well with theory.Comment: 4 pages, 5 figures - modified to take into account referees' improvement

Physical Constraints to Aquatic Plant Growth in New Zealand Lakes

The nature of aquatic plant communities often defines benthic habitat within oligotrophic and mesotrophic lakes and lake management increasingly recognizes the importance of maintaining plant diversity in order to sustain biological diversity and capacity within lakes. We have developed simple statistical relationships between key physical and vegetation variables that define the habitat requirements, or “habitat-templates”, of key vegetation types to facilitate management of plant communities in New Zealand lakes. Statistical relationships were derived from two datasets. The first was a multi-lake dataset to determine the effects of water level fluctuation and water clarity. The second dataset was from a comprehensive shoreline survey of Lake Wanaka, which allowed us to examine within-lake variables such as beach slope and wave action. Sufficient statistical relationships were established to develop a habitat template for each of the major species or assemblages. The relationships suggested that the extent and diversity of shallow-growing species was related to a combination of the extent of water level fluctuation and wave exposure. (PDF contains 9 pages.

The metabolic syndrome among Danish seafarers

Background: Representing a cluster of risk factors related to insulin resistance, the metabolic syndrome (MS) is defined by a constellation of increased waist circumference in combination with dyslipidaemia, hyperglycaemia, and/or increased blood pressure. MS is a strong risk factor for a number of chronic diseases, including diabetes and cardiovascular conditions. Approximately 1/5 of Danish adults have MS,which has an etiological relation to nutritional factors, sleep patterns, work-related stress, fatigue, and physical activity — all of which are critical issues at sea.Materials and methods: Out of 655 Danish seafarers attending medical fitness examination by seafarers’ doctors in 4 clinics, 524 participants (mean age of 38.5 years) underwent waist circumference measurements and provided questionnaire information about their workplace on board and their consumption of tobacco and alcohol. Blood samples were taken if waist circumference was increased. MS was defined according to the International Diabetes Federation as central obesity in combination with 2 out of the following conditions: elevated triglycerides, blood pressure, fasting plasma glucose, and reduced HDL-cholesterol (or treated hyperlipaemia or hypertension, or previously diagnosed type 2 diabetes, respectively).Results: The crude baseline prevalence of MS was 25.9% among male and 10.7% among female Danish seafarers. 30.6% were current smokers. The alcohol consumption was comparable to that of Danes ashore, but exceeded recommendations of 18.6%.Conclusions: MS was increased in this young group of seafarers. Seafarers with MS were advised to 10% weight-reduction, physical activity 1/2 hour/day, reduced intake of saturated fat and increased fibres in diet, smoking cessation, and control of alcohol consumption as an intervention measure. Follow-up will take place after 2 years

Option Values in Sequential Markets

We consider competitive behaviour in sequential markets when current success or failure may affect the probability of future market opportunities. The analysis is conducted in a set up which may be interpreted as two private-value, sealed-bid, second-price sequential auctions. We demonstrate that whether agents price higher or lower than in the corresponding static context depends on the relative magnitudes of the 'winner's option value' and the 'loser's option value' of participating in the later market

A large magnetic storage ring for Bose-Einstein condensates

Cold atomic clouds and Bose-Einstein condensates have been stored in a 10cm diameter vertically-oriented magnetic ring. An azimuthal magnetic field enables low-loss propagation of atomic clouds over a total distance of 2m, with a heating rate of less than 50nK/s. The vertical geometry was used to split an atomic cloud into two counter-rotating clouds which were recombined after one revolution. The system will be ideal for studying condensate collisions and ultimately Sagnac interferometry.Comment: 4 pages, 5 figure

Experimental Demonstration of Optimal Unambiguous State Discrimination

We present the first full demonstration of unambiguous state discrimination between non-orthogonal quantum states. Using a novel free space interferometer we have realised the optimum quantum measurement scheme for two non-orthogonal states of light, known as the Ivanovic-Dieks-Peres (IDP) measurement. We have for the first time gained access to all three possible outcomes of this measurement. All aspects of this generalised measurement scheme, including its superiority over a standard von Neumann measurement, have been demonstrated within 1.5% of the IDP predictions

06161 Abstracts Collection -- Simulation and Verification of Dynamic Systems

From 17.04.06 to 22.04.06, the Dagstuhl Seminar 06161 ``Simulation and Verification of Dynamic Systems\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available