Accuracy, Scalability, and Efficiency of Mixed-Element USM3D for Benchmark Three-Dimensional Flows

The unstructured, mixed-element, cell-centered, finite-volume flow solver USM3D is enhanced with new capabilities including parallelization, line generation for general unstructured grids, improved discretization scheme, and optimized iterative solver. The paper reports on the new developments to the flow solver and assesses the accuracy, scalability, and efficiency. The USM3D assessments are conducted using a baseline method and the recent hierarchical adaptive nonlinear iteration method framework. Two benchmark turbulent flows, namely, a subsonic separated flow around a three-dimensional hemisphere-cylinder configuration and a transonic flow around the ONERA M6 wing are considered

Integrating personalized medical test contents with XML and XSL-FO

Background: In 2004 the adoption of a modular curriculum at the medical faculty in Muenster led to the introduction of centralized examinations based on multiple-choice questions (MCQs). We report on how organizational challenges of realizing faculty-wide personalized tests were addressed by implementation of a specialized software module to automatically generate test sheets from individual test registrations and MCQ contents. Methods: Key steps of the presented method for preparing personalized test sheets are (1) the compilation of relevant item contents and graphical media from a relational database with database queries, (2) the creation of Extensible Markup Language (XML) intermediates, and (3) the transformation into paginated documents. Results: The software module by use of an open source print formatter consistently produced high-quality test sheets, while the blending of vectorized textual contents and pixel graphics resulted in efficient output file sizes. Concomitantly the module permitted an individual randomization of item sequences to prevent illicit collusion. Conclusions: The automatic generation of personalized MCQ test sheets is feasible using freely available open source software libraries, and can be efficiently deployed on a faculty-wide scale

Is Equality always desirable?

In this paper, we analyze the trade-off between perceived fairness and perceived attractiveness in crew rostering. First, we introduce the Fairness-oriented Crew Rostering Problem. In this problem, attractive cyclic rosters have to be constructed, while respecting a pre-specified fairness level. Then, we propose a flexible mathematical formulation, able to exploit problem specific knowledge, and develop an exact Branch-Price-and-Cut solution method. The solution method combines Branch-and-Bound with column generation, where profitable columns are separated by solving resource constrained shortest path problems with surplus variables. We also derive a set of valid inequalities to tighten the formulation. Finally, we demonstrate the benefit of our approach on practical instances from Netherlands Railways, the largest passenger railway operator in the Netherlands. We are able to construct the explicit trade-off curve between fairness and attractiveness and show that a sequential approach can lead to suboptimal results. In particular, we show that focusing solely on fairness leads to rosters that are disproportionally less attractive. Furthermore, this decrease in attractiveness is heavily skewed towards the most exible employees. Thus, in order to generate truly fair rosters, the explicit trade-off between fairness and attractiveness should be considered

Short-term studies underestimate 30-generation changes in a butterfly metapopulation

Most studies of rare and endangered species are based on work carried out within one generation, or over one to a few generations of the study organism. We report the results of a study that spans 30 generations (years) of the entire natural range of a butterfly race that is endemic to 35 km2 of north Wales, UK. Short-term studies (surveys in single years and dynamics over 4 years) of this system led to the prediction that the regional distribution would be quite stable, and that colonization and extinction dynamics would be relatively unimportant. However, a longer-term study revealed unexpectedly high levels of population turnover (local extinction and colonization), affecting 18 out of the 20 patches that were occupied at any time during the period. Modelling the system (using the 'incidence function model' (IFM) for metapopulations) also showed higher levels of colonization and extinction with increasing duration of the study. The longer-term dynamics observed in this system can be compared, at a metapopulation level, with the increased levels of variation observed with increasing time that have been observed in single populations. Long-term changes may arise from local changes in the environment that make individual patches more or less suitable for the butterfly, or from unusual colonization or extinction events that take metapopulations into alternative states. One implication is that metapopulation and population viability analyses based on studies that cover only a few animal or plant generations may underestimate extinction threats

Overwintering in New Zealand stick insects

Stick insects are found in a variety of habitats throughout New Zealand, including at least four species that occur at high altitudes. Here they face physiological challenges that differ from their typically warmer lowland habitats, but their strategies to deal with harsh winter conditions are not known. Autumn and winter field surveys, coupled with caging experiments, were conducted to determine which life stages are overwintering in montane and lowland habitats. Data loggers were placed for approximately one year at each site to measure the leaf litter and canopy microhabitat temperatures. From this, we have found that alpine and lowland stick insects persist in a variety of life stages throughout the year despite multiple exposure to freezing temperatures

Plausible responses to the threat of rapid sea-level rise for the Thames Estuary

This paper considers the perceptions and responses of selected stakeholders to a scenarion of rapid rise in sea-level due to the collapse of the West Antarctic ice sheet, which could produce a global rise in sea-level of 5 to 6 metres. Through a process of dialogue involving one-to one interviews and a one-day policy exercise, we addressed influences on decision-making when information is uncertain and our ability to plan, prepare for and implement effective ways of coping with this extreme scenario. Through these interactions we hoped to uncover plausible responses to the scenario and identify potential weaknesses in our current flood management approaches to dealing with such an occurrence. By undertaking this exploratory exercise we hoped to find out whether this was a feasible way to deal with such a low probability but high consequence scenario. It was the process of finding a solution that interested us rather than the technical merits of one solution over another. We were not intending to produce definitive set of recommendations on how to respond but to gain insights into the process of making a decision, specifically what influences it and what assumptions are made.Sea level rise, London

Uterine phosphatase concentrations and their relationship to number and weight of embryos in the rat

This bulletin reports on Department of Agricultural Chemistry Research Project 223, 'Reproductive Physiology', and Department of Animal Husbandry Research Project 222--P. [3].Digitized 2007 AES.Includes bibliographical references (page 19)

The concentration and metabolism of sugar in ram semen

Publication authorized December 16, 1941.Digitized 2007 AES.Includes bibliographical references (pages 33-35)

Survival of bovine spermatozoa in media containing a lipoprotein complex isolated from spermatozoa and other sources

This bulletin is a report of research under Project 81, 'Biochemical, Physical, and Physiological Aspects in Natural and Artificial Breeding'--P. [3].Includes bibliographical references (pages 15-16)