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NSIS Volume 43, Part 2

Permanent URI for this collectionhttps://hdl.handle.net/10222/70956

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  • ItemOpen Access
    NSIS Presidential Address and Reports from Council Officers, Session 2004-2005
    (Nova Scotian Institute of Science, 2006) Nova Scotian Institute of Science
  • ItemOpen Access
    RATIONAL DRUG DESIGN: A WINDOW INTO THE AMBITIOUS QUEST OF A NEUROLOGIST AND CHEMIST
    (Nova Scotian Institute of Science, 2006) PATERSON, JENNIFER
    In the difficult world of drug discovery, two main courses of action are open: one is to screen extensive libraries of chemical compounds against hundreds of disease models; another is to acquire a detailed understanding of the molecules involved in a particular disease, and then rationally design compounds that can interact with or block those molecules. The first approach is favoured by large pharmaceutical companies, while the second is favoured by academics. This article illustrates the pursuit of this second approach by a Dalhousie University neurologist and chemist. Through interviews with this scientist and several of his colleagues, the article reveals the science of rational drug design, as well as some of the challenges and compromises involved in bringing discoveries to comm.ercial stages.
  • ItemOpen Access
    DESIGN STUDY OF NOVEL LIGHT GUIDE GEOMETRY FOR SCINTILLATION COUNTERS
    (Nova Scotian Institute of Science, 2006) GLISTER, JACKIE; SARTY, ADAM J.
    Two scintillating panels (S1 and S2) have been used as triggers in the high resolution spectrometers in HallAofthe Thomas Jefferson NationalAccelerator Facility. New panels are to be installed in place of S1 and S2 and it was proposed that the currently used 90° twisted light guides be replaced by a new adiabatic S-shape design (2 or 3 strips). Using CERN's Guide7, Monte Carlo simulations were performed on four different light guide geometries: rectangular, standard fishtail, 2-strip S-shape and 3-strip S-shape. It was found that the two S-shape designs gave roughly 2x improvement on collection efficiency and 1.2-1 .4x improvement on time resolution oversimple designs (rectangular and fishtail). The 3-strip S-shape guide (90 pico-second time resolution and a 30% collection efficiency) was recommended for replacement of the twisted shape; actual experimental comparisons are also advised.
  • ItemOpen Access
    GROWTH AND PHENYLALANINE AMMONIA LYASE ACTIVITY OF Rhodotorula g/utinis: OPTIMIZATION OF CONDITIONS FOR THE SYNTHESIS OF L-PHENYLALANINE
    (Nova Scotian Institute of Science, 2006) WALL, MARK; D'CUNHA, GODWIN
    A procedure is described for the synthesis of L-phenylalanine from trans-cinnamic acid and ammonia utilizing the reverse reaction of phenylalanine ammonia lyase (PAL) from Rhodotoru/a glutinis. Optimal conditions determined for yeast growth and PAL production were pH 6, 1% inoculum, 30°C for 26-28 h. Optimization of conditions for maximal phenylalanine production included incubation time (16 -18 h), temperature (30°C), pH (9 .0), selected concentrations of substrates: 0.1 M trans-cinnamic acid and 4.0M NH40H and 0.1M Tris-HCI. Under these conditions about 85% conversion of substrate to product was obtained.
  • ItemOpen Access
    A COMPARISON OF METHODS FOR MODIFYING THE PARTIAL SINGULAR VALUE DECOMPOSITION IN LATENT SEMANTIC INDEXING
    (Nova Scotian Institute of Science, 2006) TOUGAS, JANE E.
    The tremendous size of the Internet and modem databases has made efficient searching and information retrieval (IR) important. Latent semantic indexing (LSI) is an IR method that represents a dataset as a term-document matrix. LSI uses a matrix factorization method known as the partial singular value decomposition (PSVD). Calculating the PSVD of a large term-document matrix is computationally expensive. In a rapidly expanding environment, a term-document matrix is altered often as new documents and terms are added. Recomputing the PSVD of the term-document matrix each time these slight alterations occur can be prohibitively expensive. Folding-in is one method of adding new documents or terms to an LSI database; updating the PSVD of the existing LSI database is another. The folding-in method is computationally inexpensive, but may cause deterioration in the accuracy of the PSVD. The PSVD-updating method is computationally more expensive than the folding-in method, but better maintains the accuracy of the PSVD. Folding-up is a new method that combines folding-in and PSVD-updating. Folding-up is faster than either recomputing the PSVD or PSVD-updating, but avoids the degradation in the PSVD that can occur when the folding-in method is used on its own.
  • ItemOpen Access
    Clear as Mud: The Type I/Type II Model for Death Receptor-Induced Apoptosis
    (Nova Scotian Institute of Science, 2006) Conrad, David Michael
    Apoptosis is a highly organized form of cell death that plays an important regulatory role in many biological processes. The relationship between the two classical signalling pathways of apoptosis, the “death receptor” and “mitochondrial” pathways, was only vaguely appreciated until 1998, when death receptor pathway-mediated activation of the mitochondrial pathway was clearly demonstrated for the first time. The “type I/type II” model of death receptor-mediated apoptosis was proposed and subsequently adopted for use in categorizing cells according to the involvement of the mitochondrion during death receptor-induced apoptosis. Since that time, however, different interpretations of the type I/type II cell definition have appeared in the literature and, consequently, the meaning of type I and type II cells has become less clear.
  • ItemOpen Access
    The Nova Scotian Institute of Science Student Science Awards 2005
    (Nova Scotian Institute of Science, 2006)
  • ItemOpen Access
    Marine Ecosystem Assessment: Past, Present and Future Attempts with Emphasis on the Eastern Scotian Shelf
    (Nova Scotian Institute of Science, 2006) Frank, Kenneth T.; Choi, Jae S.; Petrie, Brian
    The collapse of major fish stocks around the world, their failure to recover even after the cessation of fishing, and the perceived deficiencies in single species fisheries management has resulted in an intensified interest in the study of whole systems. Assessment of ecosystems is a relatively new phenomenon and represents a significant departure from the past focus on individual ecosystem components such as individual, commerciallyexploited stocks of fish and invertebrates in isolation from their physical, chemical and biological environment. A report entitled “State of the Eastern Scotian Shelf Ecosystem” was completed recently and some of its main findings form the body of this paper. The analysis focused on more than 60 data series, most extending back to at least 1970, associated with three categories of variables: biotic, abiotic and human. Biotic variables included the abundance, distribution and composition of finfish and invertebrates, phyto- and zooplankton, and marine mammals. Abiotic variables included oceanic and atmospheric data that specify ocean climate conditions. Human variables ranged from fisheries landings and revenue, activities associated with oil and gas development and contaminants. By examining temporal variations in the data, an assessment was made of the current status of the ecosystem relative to its past state.
  • ItemOpen Access
    A History of Marine Fisheries Science in Atlantic Canada and its Role in the Management of Fisheries
    (Nova Scotian Institute of Science, 2006) Halliday, R.G.; Fanning, L.P.
    The roots of fisheries science on the Atlantic coast of Canada go back to 1898. The primary research agencies were the Fisheries Research Board of Canada and predecessors until the early 1970s and subsequently the federal department responsible for fisheries. Canadian research on Atlantic fisheries expanded substantially after the Second World War, at about the time the International Commission for the Northwest Atlantic Fisheries was formed, and increased again after the 1977 extension of fisheries jurisdiction, but gradually declined from the 1980s. Initially research was directed at improving and expanding the fisheries through exploring for new resources and by introducing and testing new fishing methods and new processing technologies, but increasingly was directed towards rational exploitation of the fisheries as international fishing effort greatly expanded in the 1960s. By the 1980s, the provision of short-term advice on catch limits occupied a large proportion of science resources. This paper describes these changes with primary reference to groundfish fisheries, which were the most important for much of the period.
  • ItemOpen Access
    Biological Oceanography in Canada (with Special Reference to Federal Government Science)
    (Nova Scotian Institute of Science, 2006)
    This is a personal account of the history, accomplishments and future of biological oceanography in Canada with emphasis on Canadian government research. Canadian biological oceanographers have a rich history pre-dating the formal beginning of marine scientific research in the country with the establishment of the St Andrews and Nanaimo field stations in the early 1900s. Over the years, they have distinguished themselves by being leaders in the early developments of the discipline, including methodologies, concepts and understanding of both the pelagic and benthic ecosystems. In more recent years, Canadian biological oceanographers have led in the conceptualization, planning and implementation of major interdisciplinary/international research initiatives on climate change and ecosystem dynamics. Additionally, they are making important contributions to ecosystem and climate monitoring, research aimed at understanding the influence of ecosystems on harvestable living resource variability and on climate change, and development and application of ecosystem and climate models. Canadian biological oceanographers have made and continue to make significant contributions to the understanding of the biology of the oceans and its interactions with the physical, chemical and geological world. The challenge of solving the complex scientific and societal problems of the future will require better planning, coordination and stronger commitment to the ocean sciences by universities and government than is currently in place. Strategic planning to define goals and responsibilities is urgently needed and should include not only government and universities, but also private sector research and industry.
  • ItemOpen Access
    Physical Oceanography in Atlantic Canada
    (Nova Scotian Institute of Science, 2006) Clarke, R. Allyn
    Physical oceanography has been practiced in Atlantic Canada since the beginnings of the science in the second half of the 19th century. Pursued largely as an applied science, its efforts have been directed toward providing information to mariners and other marine users. Early efforts focused on tidal observations to promote safe navigation. This was expanded in the early 20th century to regional studies in support of fisheries. In the second half of the 20th century, physical oceanography in Atlantic Canada grew to support the offshore development of oil and gas, provide more comprehensive environmental assessments of marine projects and processes, improve Search and Rescue responses and to better understand and predict climate change and variability. Oceanographers now have the capabilities to observe the ocean in near real-time using satellites as well as autonomous in situ instruments. The continued growth in computer power and other information technologies has permitted the development of operational ocean models that can provide real-time information and projections on oceanic conditions to a broad section of the marine community.
  • ItemOpen Access
    Marine Geology in Atlantic Canada—A Government Perspective
    (Nova Scotian Institute of Science, 2006) Pickrill, Richard A.; Piper, David J.W.
    The two priorities for government marine geoscience over the next decades are: (1) seabed mapping for ocean management, including safe and sustainable use of natural resources; and (2) societal responses in the coastal zone to natural hazards, global climate change and anthropogenic pressures including environmental degradation. Meeting these priorities will require scientific study of the history of past glaciations; erosion, transport and flocculation processes of sea-floor sediments, particularly of muds; and sediment transport and deposition and their interaction with environmental quality in estuarine systems, including the role of ice and storms. Numerical models are required to predict the consequences of natural rise in sea level and human interference in coastal systems and for predictive decision making in ocean management. Three recent revolutionary developments in technology will influence how science is done: these are the development of Global Positioning Systems (GPS), of multibeam sonar, and of digital data collection, storage and dissemination. However, other capital acquisitions and technological developments are necessary. These include new ships, expanded multibeam capability, and underwater autonomous vehicles. New photographic/video systems will provide resolution higher than that of multibeam bathymetry. In the coastal zone, remote sensing tools such as Light Detection And Ranging (Lidar) and kinematic GPS will accelerate monitoring of coastal change. Cabled seabed observatories will provide time series and real-time information on extreme events. Research boreholes are essential to understand geological framework.
  • ItemOpen Access
    General Introduction: Marine Science Essays
    (Nova Scotian Institute of Science, 2006) Stewart, James E.
  • ItemOpen Access
    Front Matter
    (Nova Scotian Institute of Science, 2006)