Prentice G. Downes (1909-1959)

Prentice G. Downes was one of the most singular men to travel in the North in the last years before the 1939-45 War. An able man in the wilderness and a gifted cartographer, ethnologist, and naturalist, he is best remembered as the author of Sleeping Island: The Story of One Man's Travels in the Great Barren Lands of the Canadian North, a classic of northern canoe travel. ... In a letter to George Douglas in 1943, Downes remarked that his having read Napolean Comeau's Life and Sport on the North Shore of the St. Lawrence "had a great deal to do with my ever going north, as I was so interested that I set off for the North Shore to find the old gentleman." Comeau had died, but thus in 1935 Downes commenced his northern travels. In 1936 he took passage aboard R.M.S. Nascopie from Montreal to Churchill, during which trip he made copious notes on climate, geography, wildlife, Ungava Eskimo vocabulary, and northern society. From Churchill he flew to Pelican Narrows and with an Indian companion canoed to Reindeer Lake and back again. In 1937 the New England Museum of Natural History sponsored a solo trip by Downes to study the Eskimos of Boothia Peninsula, before which he made his way to Brochet at the north end of Reindeer Lake and investigated the histories, languages, and ways of the Crees and the Chipewyans. This fascination with northern Indians, and above all with the significance of dreams in their cultures, was central to Downes's travels. The Crees named him "The-man-who-talks-about-dreams." Two of Downes's unpublished writings are a Cree-Chipewyan dictionary and a volume titled "The Spirit World of the Northern Cree: Contributions to Cree Ethnology." The first of Downes's major canoe trips came in 1938, when he paddled alone from Waterways to Fitzgerald, after which he moved on the Great Slave, the Mackenzie, and Great Bear. ... The Sleeping Island trip of 1939 - from Brochet to Nueltin Lake - was followed by another, less triumphant, venture into that region in 1940. Despondent as he was at his failure to reach Kasba Lake by way of the Little Partridge River, Downes could still confide in his journal: "Three important routes and one previously unknown river have been worked out. Kasmere Lake is now plotted, both north and east arm. Actually, far more was accomplished than a successful trip through to Kasba would have afforded." Much of the North was as yet imperfectly mapped then, of course, and one of Downes's primary achievements was his meticulous mapping of every obscure route he followed. ..

Examining perceptions of agility in software development practice

This is the post-print version of the final published article that is available from the link below. Copyright @ 2010 ACM.Organizations undertaking software development are often reminded that successful practice depends on a number of non-technical issues that are managerial, cultural and organizational in nature. These issues cover aspects from appropriate corporate structure, through software process development and standardization to effective collaborative practice. Since the articulation of the 'software crisis' in the late-1960s, significant effort has been put into addressing problems related to the cost, time and quality of software development via the application of systematic processes and management practices for software engineering. Early efforts resulted in prescriptive structured methods, which have evolved and expanded over time to embrace consortia/ company-led initiatives such as the Unified Modeling Language and the Unified Process alongside formal process improvement frameworks such as the International Standards Organization's 9000 series, the Capability Maturity Model and SPICE. More recently, the philosophy behind traditional plan-based initiatives has been questioned by the agile movement, which seeks to emphasize the human and craft aspects of software development over and above the engineering aspects. Agile practice is strongly collaborative in its outlook, favoring individuals and interactions over processes and tools, working software over comprehensive documentation, customer collaboration over contract negotiation, and responding to change over following a plan (see Sidebar 1). Early experience reports on the use of agile practice suggest some success in dealing with the problems of the software crisis, and suggest that plan-based and agile practice are not mutually exclusive. Indeed, flexibility may arise from this unlikely marriage in an aim to strike a balance between the rigor of traditional plan-based approaches and the need for adaptation of those to suit particular development situations. With this in mind, this article surveys the current practice in software engineering alongside perceptions of senior development managers in relation to agile practice in order to understand the principles of agility that may be practiced implicitly and their effects on plan-based approach

Studying the effect of chloroquine on sporozoite-induced protection and immune responses in Plasmodium berghei malaria

BACKGROUND Sporozoite immunization of animals and humans under a chemo-prophylactic cover of chloroquine (CPS-CQ) efficiently induces sterile protection against malaria. In humans, CPS-CQ is strikingly more efficient than immunization with radiation attenuated sporozoites (RAS), raising the hypothesis that this might be partially due to CQ. Chloroquine, an established anti-malarial drug, is also well known for its immune modulating properties including improvement of cross-presentation. The aim of this study was to investigate whether co-administration of CQ during sporozoite immunization improves cellular responses and protective efficacy in Plasmodium berghei models. METHODS A number of experiments in selected complimentary P. berghei murine models in Balb/cByJ and C57BL/6j mice was performed. First, the effect of CQ administration on the induction of protection and immune responses by RAS immunization was studied. Next, the effect of CQ on the induction of circumsporozoite (CS) protein-specific CD8(+) T cells by immunization with P. berghei parasites expressing a mutant CS protein was investigated. Finally, a direct comparison of CPS-CQ to CPS with mefloquine (MQ), an anti-malarial with little known immune modulating effects, was performed. RESULTS When CQ was co-administered during immunization with graded numbers of RAS, this did not lead to an increase in frequencies of total memory CD8(+) T cells or CS protein-specific CD8(+) T cells. Also parasite-specific cytokine production and protection remained unaltered. Replacement of CQ by MQ for CPS immunization resulted in significantly reduced percentages of IFNγ producing memory T cells in the liver (p = 0.01), but similar protection. CONCLUSIONS This study does not provide evidence for a direct beneficial effect of CQ on the induction of sporozoite-induced immune responses and protection in P. berghei malaria models. Alternatively, the higher efficiency of CPS compared to RAS might be explained by an indirect effect of CQ through limiting blood-stage exposure after immunization or to increased antigen exposure and, therefore, improved breadth of the immune response.EMB was supported by Top Institute Pharma (grant T4-102) and KN was supported by the NWO Mozaiek (grant no. 017.005.011)

The Global Threat of Counterfeit Drugs: Why Industry and Governments Must Communicate the Dangers

The production of substandard and fake drugs is a vast and underreported problem, particularly affecting poorer countries. Cockburn and colleagues argue that the pharmaceutical industry and governments must both take actio

One-Sided Position-Dependent Smoothness-Increasing Accuracy-Conserving (SIAC) Filtering Over Uniform and Non-Uniform Meshes

In this paper, we introduce a new position-dependent Smoothness-Increasing Accuracy-Conserving (SIAC) filter that retains the benefits of position dependence while ameliorating some of its shortcomings. As in the previous position-dependent filter, our new filter can be applied near domain boundaries, near a discontinuity in the solution, or at the interface of different mesh sizes; and as before, in general, it numerically enhances the accuracy and increases the smoothness of approximations obtained using the discontinuous Galerkin (dG) method. However, the previously proposed position-dependent one-sided filter had two significant disadvantages: (1) increased computational cost (in terms of function evaluations), brought about by the use of $4k+1$ central B-splines near a boundary (leading to increased kernel support) and (2) increased numerical conditioning issues that necessitated the use of quadruple precision for polynomial degrees of $k\ge 3$ for the reported accuracy benefits to be realizable numerically. Our new filter addresses both of these issues --- maintaining the same support size and with similar function evaluation characteristicsas the symmetric filter in a way that has better numerical conditioning --- making it, unlike its predecessor, amenable for GPU computing. Our new filter was conceived by revisiting the original error analysis for superconvergence of SIAC filters and by examining the role of the B-splines and their weights in the SIAC filtering kernel. We demonstrate, in the uniform mesh case, that our new filter is globally superconvergent for $k=1$ and superconvergent in the interior (e.g., region excluding the boundary) for $k\ge2$. Furthermore, we present the first theoretical proof of superconvergence for postprocessing over smoothly varying meshes, and explain the accuracy-order conserving nature of this new filter when applied to certain non-uniform meshes cases. We provide numerical examples supporting our theoretical results and demonstrating that our new filter, in general, enhances the smoothness and accuracy of the solution. Numerical results are presented for solutions of both linear and nonlinear equation solved on both uniform and non-uniform one- and two-dimensional meshes

Multi-dimensional filtering: Reducing the dimension through rotation

Over the past few decades there has been a strong effort towards the development of Smoothness-Increasing Accuracy-Conserving (SIAC) filters for Discontinuous Galerkin (DG) methods, designed to increase the smoothness and improve the convergence rate of the DG solution through this post-processor. These advantages can be exploited during flow visualization, for example by applying the SIAC filter to the DG data before streamline computations [Steffan et al., IEEE-TVCG 14(3): 680-692]. However, introducing these filters in engineering applications can be challenging since a tensor product filter grows in support size as the field dimension increases, becoming computationally expensive. As an alternative, [Walfisch et al., JOMP 38(2);164-184] proposed a univariate filter implemented along the streamline curves. Until now, this technique remained a numerical experiment. In this paper we introduce the line SIAC filter and explore how the orientation, structure and filter size affect the order of accuracy and global errors. We present theoretical error estimates showing how line filtering preserves the properties of traditional tensor product filtering, including smoothness and improvement in the convergence rate. Furthermore, numerical experiments are included, exhibiting how these filters achieve the same accuracy at significantly lower computational costs, becoming an attractive tool for the scientific visualization community