Andrew Thomson, O.B.E. (1893-1974)

The many friends and colleagues of Dr. Thomson, former Director of the Canadian Meteorological Service and a Fellow of the Arctic Institute since 1954, will be saddened to hear of his death on 17 October 1974 in Toronto. He was 81. Andrew Thomson was born near Owen Sound, Ontario, on 18 May 1893. He graduated from the University of Toronto in 1915 in Honours Physics, and later earned a Master's degree from the same institution. In 1958, he was awarded an honorary doctorate in science by McGill University. Following a lengthy period abroad, during which time he worked with the Carnegie Institute in the United States, and in the South Pacific as director of the geophysical observatory at Apia in Western Samoa, Dr. Thomson returned to Canada in 1931. In January 1932, he was appointed head of the Physics Division of the Meteorological Service of Canada. Despite a reduced budget during the depression years, he was the prime organizer and promoter of Canadian participation in the second International Polar Year. He was also responsible for the organization of a post-graduate course in meteorology at the University of Toronto, which was given in cooperation with the Meteorological Service of Canada. Shortly after the outbreak of the war in 1939, the British Commonwealth Air Training Plan was conceived and Dr. Thomson became the main organizer and administrator of the extensive meteorological programme that was required. For his contributions to the war effort, Dr. Thomson was awarded the Order of the British Empire in 1948. Following the war, Dr. Thomson undertook the reorganization of the Canadian Meteorological Service on to a peace-time basis. He was appointed Controller (later Director) of the Meteorological Service in 1946. In this capacity, he planned and supervised the installation of the Joint (U.S.-Canada) Arctic Weather Stations, and also promoted Canada's active participation in international meteorological affairs. By the time he retired in 1959, Dr. Thomson had presided over a rapid and remarkable period of growth for meteorology in Canada, one during which there were marked advances in climatology, forecasting, research, instrument design, and training methods. Dr. Thomson was a Fellow of the Royal Society of Canada and of the Institute of Physics of Great Britain. He was also Vice-President of the American Meteorological Society and a member of the Royal Astronomical Society of Canada, of the Royal Canadian Institute and of the Washington Academy of Science. A pleasant, kindly man, Andrew Thomson was known for his quick mind and keen intelligence. A unique figure in Canadian meteorology for more than forty years, he was in many ways responsible for the stature the Meteorological Service has attained, both in government circles and in the public view

A Distinctive Large Breeding Population of Ringed Seals (Phoca hispida) Inhabiting the Baffin Bay Pack Ice

Aerial surveys in June and July, 1978 and 1979, documented an unexpectedly large population (at least 417,000) of ringed seals, some with pups, inhabiting the pack ice of Baffin Bay. Pack-ice seals are smaller than their fast-ice counterparts and have a different diet and gut parasite load. Age and productive data, although limited, indicate that the offshore seals are a normal breeding population. Pack-ice seals probably mix with fast-ice seals in coastal areas during the brief open-water season but morphological and ecological differences suggest that the populations are reproductively isolated. This study prompts reconsideration of the importance of offshore pack ice to ringed seals and, therefore, to the coastal hunting economy of Inuit in Greenland and Baffin Island.Key words: ringer seals, Baffin Bay, pack ice, distribution, population discreteness, managementDes inventaires aériens effectués en juin et juillet, 1978 et 1979, ont documenté une population importante d'au moins 417 000 phoques annelés, certains accompagnés de jeunes, habitant le pack de la baie Baffin. Les phoques du pack sont plus petits que ceux de la banquise côtière et ont un régime alimentaire et des parasites intestinaux différents. Des données sur l'âge et le reproduction, quoique limitées, indiquent que les phoques au large des côtes suivent un cycle de reproduction normal. Les phoques du pack se mêlent probablement à ceux de la banquise dans les régions côtières durant la brève saison d'eau libre mais les différences morphologiques et écologiques suggèrent que les populations se reproduisent peut-être indépendamment l'une de l'autre. La présente étude encourage une reconsidération de l'importance du pack chez les phoques annelés et ainsi, de son importance dans 1'économie côtière des Inuit chasseurs du Groenland et de l'île de Baffin.Mots clés: phoque annelés, baie Baffin, banquise, distribution, isolation reproductrice de la population, contrôle de la populatio

Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel by Atom Probe Tomography

We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 °C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe)3Ti and (Ni,Fe)3(Al,Mn) precipitates eventually form after isothermal aging for ~60 seconds. The morphology of the (Ni,Fe)3Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe)3(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe)3Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation

CHANDRA Observations of X-ray Jet Structure on kpc to Mpc Scales

With its exquisite spatial resolution of better than 0.5 arcsecond, the Chandra observatory is uniquely capable of resolving and studying the spatial structure of extragalactic X-ray jets on scales of a few to a few hundred kilo-parsec. Our analyses of four recent Chandra images of quasar jets interpret the X-ray emission as inverse Compton scattering of high energy electrons on the cosmic microwave background. We infer that these jets are in bulk relativistic motion, carrying kinetic powers upwards of 10^46 ergs/s to distances of hundreds of kpc, with very high efficiency.Comment: 4 pages, 3 figures, to be published in the proceedings of the Bologna jet workshop, "The Physics of Relativistic Jets in the CHANDRA and XMM Era.

Automated phenotyping of mosquito larvae enables high-throughput screening for novel larvicides and offers potential for smartphone-based detection of larval insecticide resistance

Pyrethroid-impregnated nets have contributed significantly to halving the burden of malaria but resistance threatens their future efficacy and the pipeline of new insecticides is short. Here we report that an invertebrate automated phenotyping platform (INVAPP), combined with the algorithm Paragon, provides a robust system for measuring larval motility in Anopheles gambiae (and An. coluzzi) as well as Aedes aegypti with the capacity for high-throughput screening for new larvicides. By this means, we reliably quantified both time- and concentration-dependent actions of chemical insecticides faster than using the WHO standard larval assay. We illustrate the effectiveness of the system using an established larvicide (temephos) and demonstrate its capacity for library-scale chemical screening using the Medicines for Malaria Venture (MMV) Pathogen Box library. As a proof-of-principle, this library screen identified a compound, subsequently confirmed to be tolfenpyrad, as an effective larvicide. We have also used the INVAPP / Paragon system to compare responses in larvae derived from WHO classified deltamethrin resistant and sensitive mosquitoes. We show how this approach to monitoring larval response to insecticides can be adapted for use with a smartphone camera application and therefore has potential for further development as a simple portable field-assay with associated real-time, geo-located information to identify hotspots

Keratoacanthoma management: results of a survey of UK dermatologists and surgeons.

Distinction of keratoacanthoma (KA) from squamous cell carcinoma (SCC) is challenging. Management is controversial, with some advocating prompt surgical excision and others monitoring to allow for spontaneous resolution(1) . The controversy is compounded by rare reports of metastasis(2) . And yet the benign natural history of KA is supported by various studies, including a systematic review of 455 cases with no cases of metastasis or death(1) , and observational studies confirming spontaneous resolution(1)

Fractional conservation laws in optimal control theory

Using the recent formulation of Noether's theorem for the problems of the calculus of variations with fractional derivatives, the Lagrange multiplier technique, and the fractional Euler-Lagrange equations, we prove a Noether-like theorem to the more general context of the fractional optimal control. As a corollary, it follows that in the fractional case the autonomous Hamiltonian does not define anymore a conservation law. Instead, it is proved that the fractional conservation law adds to the Hamiltonian a new term which depends on the fractional-order of differentiation, the generalized momentum, and the fractional derivative of the state variable.Comment: The original publication is available at http://www.springerlink.com Nonlinear Dynamic

Study on the Implications of Asynchronous GMO Approvals for EU Imports of Animal Feed Products

The aim of this study is to understand the implications of asynchronous approvals for genetically modified organisms (GMOs) that are imported to the European Union for use within animal feed products, specifically with regard to the EU livestock sector, as well as upon the upstream and downstream economic industries related to it. Asynchronous approval refers to the situation in which there is a delay in the moment when a genetically modified (GM) event – modifying a specific trait of a plant or animal – is allowed to be used in one country in comparison to another country. In the perspective of this study, the asynchronous GMO approvals concern the use of GM varieties of plants that are approved in the countries which supply them to the EU, in one form or another of feed material, before these are approved by the EU