Evaluación de Riesgos Laborales por puestos

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Influence of North Pacific decadal variability on the western Canadian Arctic over the past 700 years

Influence of North Pacific decadal variability on the western Canadian Arctic over the past 700 years

These meridional wind anomalies appear to persist dur- ing the cold season (Fig. S9), although they are not as pronounced over the western Canadian Arctic as in SON (Fig. 6a). This is consistent with annual surface wind stress differences between PDO phases over the North Pacific (Zhang and Delworth, 2015) during the 20th century (Fig. 7). Indeed, sustained southerly wind anomalies are observed in the northernmost part of the Pacific during PDO − (in- duced by a weakened Aleutian Low, i.e. NPI + ), north of the Kuroshio–Oyashio Extension, where warm SST anoma- lies are observed (Screen and Francis, 2016; Zhang and Del- worth, 2015) (Fig. 7). These southerly winds extend from the northernmost Pacific (north of the weakened Aleutian Low) across the Bering Strait and can reach as far as the west- ern Canadian Arctic, increasing heat and moisture transport to the latter region (Screen and Francis, 2016). Meanwhile, strong westerly winds dominate over the eastern Siberian Shelf and converge with the southerly flow from the Pa- cific over the western High Arctic during PDO − (Kwon and Deser, 2007; Screen and Francis, 2016; Zhang and Del- worth, 2015) (Fig. 7). Thus, the PDO phase has been shown to clearly influence the winter-mean atmospheric circulation in the North Pacific, while its influence also extends into the Arctic (Screen and Francis, 2016). Our analysis suggests that this PDO (NPI) influence might also impact regional climate during autumn.
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Impacts of the changing ocean sea ice system on the key forage fish arctic cod (Boreogadus saida) and subsistence fisheries in the Western Canadian arctic evaluating linked climate, ecosystem and economic (CEE) models

Impacts of the changing ocean sea ice system on the key forage fish arctic cod (Boreogadus saida) and subsistence fisheries in the Western Canadian arctic evaluating linked climate, ecosystem and economic (CEE) models

The pan-Arctic representation of NAA-CanOE-CSIB model has been evaluated in detail in Hayashida et al. (2018) and Hayashida (2018) and shows good correspondence with available observations. A more detailed analysis with respect to recent changes in the Western Canadian Arctic is included in the Supplementary Material (section S1.2). Arctic cod are tightly linked to the sea-ice habitat with young Arctic cod feeding under the ice on small zooplankton species that are feeding on ice algae. Hence, changes in ice algae production and distribution have direct impacts on the recruitment and distribution of Arctic cod. Models which include ice algae explicitly might therefore provide information that directly affects the distribution and abundance of Arctic cod. Simulated changes which might affect forage fish distribution and abundance and impact subsistence fisheries are evaluated here. The NAA-CanOE-CSIB simulations indicate the ISR as productive with respect to both ice algal and pelagic production. Figures 3a,b show the simulated production averaged from 1979 to 2015. Higher values are shown within the CPS than in the open Beaufort Sea (which is known for its low nutrient content). Averaged over the CPS, Beaufort Shelf and Beaufort Basin (Figure 3c), ice algae are suggested to increase in the CPS, but show little change in the Beaufort Shelf and Basin. Interannual variability over the CPS is high and seems to be increasing (Figure 3d). This might be a significant contributor to interannual changes in forage fish distribution and abundances. A regional trend analysis for the model suggests an increase in ice algae on the Beaufort Shelf and some part of the CPS in spring, but a decrease in some other parts over the period
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The tundra and polar semi-desert landscapes of Banks Island and Prince Patrick Island, Western Canadian Arctic

The tundra and polar semi-desert landscapes of Banks Island and Prince Patrick Island, Western Canadian Arctic

Banks Island contains a number of different physiographic regions (see Fig. 1). The northeast plateau consists of Devonian age limestone and the southern uplands consist of Precambrian gabbro rocks. These rocks form upland terrain rising to elevations of ~700 m. By contrast, the majority of the central and western lowlands are underlain by poorly consolidated Mesozoic-age sediments that vary in lithology from shale of the Christopher Formation to sands and gravels of the Eureka Sound and Beaufort Formations (Thorsteinsson and Tozer, 1962; Miall, 1979; Fyles, 1994). Fluvial dissection has resulted in relative relief that varies from less than 50 m to over 250 m. The interfluves and upper slopes are covered with an extensive but thin veneer of till and glacio-fluvial deposits. Much of the lowland landscape consists of broad fluvial surfaces, probably formed by melt-water that flowed westwards away from the decaying Laurentide ice sheet to the east. The most deeply dissected terrain occurs in the central, north-central and south- central parts of the island where relatively more cohesive shale and sandstone of the Christopher and Eureka Sound Formations are exposed in the valleys of the Thomsen, Kellett, Sachs and Masik Rivers. An extensive area of hummocky moraine mantles the eastern side of the island; this reflects the western edge of the Laurentide ice sheet.
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View of Neoliberalism and Homelessness in  the Western Canadian Arctic

View of Neoliberalism and Homelessness in the Western Canadian Arctic

In a territory that boasts the highest per capita income in Canada (Wilson, 2009), the problems plaguing Inuvik, and indeed much of the North, are unacceptable. A realistic first step forward is to adopt a housing first approach (Waegmakers Schiff & Rook, 2012). This approach advances that shelter is essential to address chronic issues such as addictions and mental health. While acceptable behaviour is expected, abstinence from substances is not assumed. Providing adequate support and resources have proven beneficial in terms of improved health and reductions in substance abuse in both urban and rural settings (Waegmakers Schiff & Rook, 2012). Ironically, the costs of housing first are significantly less than not doing anything, as Canadian taxpayers spend upward of $6 billion annually to cover the costs associated with healthcare, criminal justice, social services, and emergency shelters (Laird, 2007). Even more ironic is the fact that nonprofit agencies working in northern communities, such as the Salvation Army’s shelter in Whitehorse, face a daily struggle to survive (Laird, 2007).
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Observations of Beachcast Bowhead Whales ( Balaena mysticetus ) in the Southeastern Beaufort Sea and Amundsen Gulf, 1987–2016

Observations of Beachcast Bowhead Whales ( Balaena mysticetus ) in the Southeastern Beaufort Sea and Amundsen Gulf, 1987–2016

Finally, based on the absence of observed harpoons, floats or ropes, or other signs of prior strikes, there was no indication of beachcast Bowhead Whales having been struck-but-lost by harvesters, as reported in Alaska (NOAA 2017a). The only recent subsistence harvests of Bowhead Whales in the western Canadian Arctic were in 1991 (Freeman et al. 1992) and 1994 (Harwood and Smith 2002). Prior to the 1991 harvest, the last re corded landed bowhead in this region was in 1925 (McGhee 1988). The reasons for the concentration of reported mortalities in the mid–early 2000s are not known, but for the reasons above, we do not attribute these to be hunting losses by Canadian hunters.
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The impact of global warming on the geopolitics of the Arctic. A historical opportunity for Russia? Egmont Security Policy Brief No. 8, March 2010

The impact of global warming on the geopolitics of the Arctic. A historical opportunity for Russia? Egmont Security Policy Brief No. 8, March 2010

Ingredients for conflict are undoubtedly present in the Arctic. Territorial claims and access to resources are typical causes of conflict. Dwindling hydrocarbon resources makes securing access to new energy sources all the more important. In addition, states seek to control territory to prevent others from gaining access to its resources. However, all littoral states have not yet introduced their submissions so that the extent of possible overlapping claims and the subsequent recommendations by the CLCS are not clear yet. For the time being, economic activity is developing slowly and is taking place in areas where there are no overlapping claims. Moreover, the perspectives for the energy industry are long-term. The increasing military focus on the area has not turned into a regional arms race but rather reflects a desire to assert sovereignty and signal interests. The question is what will happen when further Arctic melting, technological progress and the need to tap
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Donald Evan McAllister, 1934-2001: The Growth of Ichthyological Research at the National Museum of Canada/Canadian Museum of Nature

Donald Evan McAllister, 1934-2001: The Growth of Ichthyological Research at the National Museum of Canada/Canadian Museum of Nature

Don was an innovator in museum procedures, pub- lishing a chapter on methods of collecting and pre- serving fishes in 1965, and using x-rays for taxonomic studies in numerous papers. He was a pioneer and advo- cate for the computerization of museum collections and devised a detailed field data input sheet for stan- dardizing information recorded with specimens. The compleat minicomputer cataloguing and research sys- tem for a museum was co-authored with R. Murphy and J. Morrison in 1978. Don also compiled a com- prehensive list of terms and definitions (since expand- ed by BWC and available at www.briancoad.com). Another project was a file and reprint library of ichthy- ological papers from around the world with particular emphasis on Canada and especially on the Arctic. Don organized the 1974 Annual Meeting of the American Society of Ichthyologists and Herpetologists in Ottawa, only the third time the society had met in Canada and the first to be bilingual. Don was an active member of the Fish and Marine Mammals Subcommittee of COSEWIC (Committee on the Status of Endangered Wildlife in Canada) and wrote the first endangered fish list for Canada (1970). A complete bibliography, compiled by BWC follows this tribute.
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Cognitive Impairment and the Mediterranean Diet: a Canadian Perspective

Cognitive Impairment and the Mediterranean Diet: a Canadian Perspective

Relevant data from the CCHS 2.2 were mined at the Western University RDC and exploratory data analyses were performed. The dataset was selected because it is the most current, large survey of its kind in Canada that contains relevant dietary information. Variables of interest were age (categorized), gender, province, geographical classification (urban or rural), daily macronutrient intakes (in grams), alcohol intake (in grams), energy from all food sources (in kilocalories), percentage of energy from specific macronutrients, and dementia risk status (healthy or at-risk). The only inclusion criteria for the sample selection was age (over 50) and not missing any responses pertaining to the abovementioned variables of interest. Respondents with incomplete or missing variables of interest were not considered for this study. The macronutrient variables include carbohydrates, proteins, fats, saturated fats (SFs), monounsaturated fatty acids (MUFAs), and polyunsaturated fatty acids (PUFAs). SFs, MUFAs, and PUFAs are a subset of fats and these values are not added to the overall daily fat intake. Furthermore, there are other types of fats not accounted for by this breakdown and the total daily fat intake value, therefore, is greater than the sum of these three types. The study variables were derived from questionnaire and interview responses and are only an estimate of the macronutrient composition of the respondents’ diets. The variables were selected because they are the best available method of quantifying the CanDi given the available data.
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Late winter biogeochemical dynamics under sea ice in the Canadian High Arctic

Late winter biogeochemical dynamics under sea ice in the Canadian High Arctic

With the CIB located on the continental shelf (Fig. 1a), the biogeochemical dynamics could be influenced by land- and/or sediment-associated processes, as well as shallow mixing dynamics (Prinsenberg & Ingram 1991) and may not be representative of conditions offshore, in the central basin of the Arctic Ocean. Therefore, the Catlin Arctic Survey also collected samples along a transect*the CET*from above the north coast of Ellesmere Island towards the North Pole (Fig. 1b). The CET crossed the Makarov Basin (water depth 1000 m), over the Lomonosov Ridge and into the Amundsen Basin (water depth 4000 m), thus crossing Pacific-influenced water masses, similar to those expected to enter the Canadian Arctic Archipelago near the CIB (Jones et al. 1998) and exemplified by the surface nutrient data from the CET closely following the phosphatenitrate relation- ship described by Jones et al. (1998), as illustrated in Fig. 6d.
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Natural analogue constraints on Europa's non ice surface material

Natural analogue constraints on Europa's non ice surface material

Plain Language Summary Europa, a moon of Jupiter, has become a priority target in the search for life off the Earth, due to the presence of a liquid water ocean under its icy shell. Salts on the moon's surface might originate from this ocean and therefore offer a way of studying the ocean without requiring direct access. Our knowledge of these salts comes from comparing spacecraft measurements to pure salts produced in laboratories. We have studied natural salts from hypersaline springs in the Canadian Arctic as an alternative, complementary approach. Measuring samples from these deposits at europan surface temperatures, several unexpected properties were observed, including the absence of spectral details predicted by previous laboratory studies. This challenges some of the estimates of europan surface composition. Natural analogues such as these will form part of an integrative approach to understanding data from upcoming missions, such as the National Aeronautics and Space Administration's (NASA) Europa Clipper and the European Space Agency's JUpiter ICy moons Explorer.
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Ice-nucleating particles in Canadian Arctic sea-surface microlayer and bulk seawater

Ice-nucleating particles in Canadian Arctic sea-surface microlayer and bulk seawater

We conclude that the concentrations and properties of INPs in the microlayer and bulk seawater in the Canadian Arctic are similar to other locations previously studied. How- ever, there were some important differences. On average, the concentration of INPs in the microlayer in the current study was lower than the average concentration of INPs measured by Wilson et al. (2015). These differences could not be ex- plained by chlorophyll a concentrations from satellite mea- surements. In addition, similar concentrations of INPs in the microlayer and bulk seawater were observed here, while Wil- son et al. (2015) observed significant enrichment of INPs in the microlayer compared to the bulk seawater. The differ- ences may be related to sampling techniques, but they could also be due to the oceanic state during sampling. Further studies are needed to understand how measured concentra- tions of INPs in the microlayer and bulk seawater depend on sampling techniques. Further studies are also needed to understand how measured concentrations of INPs in the mi- crolayer and bulk seawater depend on oceanic variables, par- ticularly changing sea ice distributions.
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Large-scale temperature and salinity changes in the upper Canadian Basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

Large-scale temperature and salinity changes in the upper Canadian Basin of the Arctic Ocean at a time of a drastic Arctic Oscillation inversion

Recently, the Arctic atmospheric forcing changed drasti- cally. Following a period of a positive AO phase ending in 2008, the winter (December–January–February) average of the standardized AO index dropped from 0.86 in 2008 to − 3.42 in 2010, reaching the lowest value since 1950 (see Fig. 1). This recent evolution of the AO represents one of the most abrupt shifts during the last decades. It is compa- rable in magnitude (but opposite in sign) to the shift ob- served in the late 1980s, which was responsible for some ma- jor changes in sea ice advection (Kwok, 2000; Rigor et al., 2002) and oceanic circulation (Dickson et al., 2000) in the Arctic Ocean, with consequences on the Northern Atlantic deep convection (Gerdes et al., 2008). In such a context, what could be the response of the upper Arctic Ocean to the dras- tic increase of the atmospheric anticyclonicity that occurred between 2008 and 2010?
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Impact of the Healthy Foods North nutrition intervention program on Inuit and Inuvialuit food consumption and preparation methods in Canadian Arctic communities

Impact of the Healthy Foods North nutrition intervention program on Inuit and Inuvialuit food consumption and preparation methods in Canadian Arctic communities

intervention components and materials. The fourth phase involved 3-day training for intervention trainees, local com- munity health representatives, project coordinators, and local store staff and the fifth phase was the actual program implementation and evaluation. Elders and community members emphasized the importance of ‘ country’ foods (foods from the land, air, or sea such as caribou, seal, fish, ptarmigan, goose, or berries); as such, many of the interven- tion materials focused on ways to prepare traditional foods. Traditional procurement practices, such as hunting, fishing, collecting ice water, and berry picking also promote phys- ical activity, which was another important HFN interven- tion program component. Promotion of healthy foods and de-promotion of unhealthy foods was undertaken in gro- cery stores, at community sites, through posters, flyers, interactive sessions, educational displays, and through media such as radio and television announcements [13]. For example, materials were developed to promote con- sumption of water in place of carbonated beverages and posters displayed nutrient content comparisons between traditional meat such as Arctic char and caribou versus processed meat in grocery stores [28]. Program implemen- tation strategies included healthy breakfasts, healthy meal planning and cooking, and education sessions on consum- ing sufficient amounts of vitamins and minerals, among other activities to promote healthy diet. Implementation sites included food stores, health clinics, offices, as well as at community special events, such as feasts [23]. Similar in- terventions were displayed through local television ads, and local radio broadcast stories featuring family activities to improve diet and exercise [32].
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Thermodynamic and dynamic ice thickness contributions in the Canadian Arctic Archipelago in NEMO-LIM2 numerical simulations

Thermodynamic and dynamic ice thickness contributions in the Canadian Arctic Archipelago in NEMO-LIM2 numerical simulations

Abstract. Sea ice thickness evolution within the Canadian Arctic Archipelago (CAA) is of great interest to science, as well as local communities and their economy. In this study, based on the NEMO numerical framework including the LIM2 sea ice module, simulations at both 1/4 and 1/12 ◦ hor- izontal resolution were conducted from 2002 to 2016. The model captures well the general spatial distribution of ice thickness in the CAA region, with very thick sea ice ( ∼ 4 m and thicker) in the northern CAA, thick sea ice (2.5 to 3 m) in the west-central Parry Channel and M’Clintock Channel, and thin (< 2 m) ice (in winter months) on the east side of CAA (e.g., eastern Parry Channel, Baffin Island coast) and in the channels in southern areas. Even though the configu- rations still have resolution limitations in resolving the exact observation sites, simulated ice thickness compares reason- ably (seasonal cycle and amplitudes) with weekly Environ- ment and Climate Change Canada (ECCC) New Ice Thick- ness Program data at first-year landfast ice sites except at the northern sites with high concentration of old ice. At 1/4 to 1/12 ◦ scale, model resolution does not play a significant role in the sea ice simulation except to improve local dynamics because of better coastline representation. Sea ice growth is decomposed into thermodynamic and dynamic (including all non-thermodynamic processes in the model) contributions to study the ice thickness evolution. Relatively smaller thermo- dynamic contribution to ice growth between December and the following April is found in the thick and very thick ice regions, with larger contributions in the thin ice-covered re- gion. No significant trend in winter maximum ice volume
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"Everyone Should Have a Voice, Everyone's Equal": Gender, Decision Making and Environmental Policy in the Canadian Arctic

"Everyone Should Have a Voice, Everyone's Equal": Gender, Decision Making and Environmental Policy in the Canadian Arctic

"Everyone Should Have a Voice, Everyone's Equal" Gender, Decision Making and Environmental Policy in the Canadian Arctic JOANNA KAFAROWSKI Dans La lointaine Arctique, les chasseurs et truppeurs Inuits[.]

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Food expenditure patterns in the Canadian Arctic show cause for concern for obesity and chronic disease

Food expenditure patterns in the Canadian Arctic show cause for concern for obesity and chronic disease

adequate nutrition, but provide relatively high levels of energy. NNDF includes a relatively large group of items that were usually available in community food stores, in contrast to fresh produce, which was not as readily avail- able on a consistent basis. This suggests that, on a daily basis, most of the NNDF items were more available than fresh produce. For individuals who are food shopping for the entire family, the purchase of NNDF may be the easiest way of obtaining the most energy while ensuring that all members of the family were satisfied. In addition, a taste preference may exist for high fat foods [19]. Drewnowski and Specter [20] reported that the relation- ship between obesity and poverty can be explained by the low cost of foods that are energy dense and the taste and acceptability of these foods that are usually high in fat and sugar. Affordability, quality of store-bought per- ishable foods, exposure to fresh produce, and culinary knowledge are other factors that could be linked to lower expenditure on nutrient-dense food groups, par- ticularly fruit and vegetables. Increased cost of fuel and hunting equipment, as well as reduced availability of land, sea and sky resources, such as caribou, Arctic char, and geese, possibly as a result of climate changes [21], are potential reasons that traditional meats expenditure is lower than non-traditional meat expenditure among this population.
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Dimethyl sulfide dynamics in first year sea ice melt ponds in the Canadian Arctic Archipelago

Dimethyl sulfide dynamics in first year sea ice melt ponds in the Canadian Arctic Archipelago

Results from this study confirm the presence of DMS in Arc- tic melt ponds, with concentrations up to three times higher than those reported by the two other previous Arctic studies. Salinization of melt ponds appears to be a prerequisite to the presence of DMS and its de novo biological production. In- trusion of seawater through porous sea ice and low freeboard flooding seems to be a fundamental mechanism for bringing salt and DMS in the melt ponds as well as allowing the estab- lishment of potential DMS-producing communities. As melt ponds become closely levelled with seawater, small changes in ice temperature oscillating around the freezing tempera- ture may result in episodic intrusion of seawater mixed with meltwater through the porous ice. Seawater mixed with melt- water penetrating the brines channels of permeable sea ice may bring salts, nutrients, and microorganisms potentially seeding surface melt ponds. Results from incubation experi- ments reveal a modest but measurable in situ net production of DMS in one of the melt ponds tested. Our results also sug- gests that melt ponds can host an active bacterial assemblage associated with rapid DMSP uptake and significant produc- tion of DMS. Freshwater ponds lacked the potential to pro- duce DMS, further confirming the importance of the seawa- ter intrusion mechanism in the biological cycling of DMS in melt ponds. No DMSO-to-DMS reduction was detected in our study.
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"Smile and Carry On:" Canadian Cavalry on the Western Front, 1914-1918

"Smile and Carry On:" Canadian Cavalry on the Western Front, 1914-1918

The 1 st Hussars voyage became all the more precarious as they approached England, where they came under threats from German submarines. On 20 June, Leonard described passing a vessel at half speed with all the lights turned off. 124 When the S.S. Caledonian passed through Cornwall’s Lizard Point 125 on 21 June, Leonard received word that an escort had been sent to look for the vessel to ensure its safe passage into Plymouth. 126 All drills were cancelled, and troops were ordered to stay below the deck of the ship. According to Leonard’s diary, the “Captain got several wireless in code saying that submarines were very active around the Lizard, so we had a very anxious night until we passed the Eddystone Light House 127 a little after midnight. The Captain felt very relieved.” 128 As the S.S. Caledonian approached Plymouth, the ship was delayed again, as the protective escort was unable to locate the ship because its lights were off and they were in the midst of a heavy fog. 129 After a total of thirteen days at sea, the Hussars disembarked by 1:00pm on 22 June and boarded their train to the Canadian Cavalry Depot in Canterbury by 4:00pm. 130
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Measurements of the dissolved inorganic carbon system and associated biogeochemical parameters in the Canadian Arctic, 1974–2009

Measurements of the dissolved inorganic carbon system and associated biogeochemical parameters in the Canadian Arctic, 1974–2009

Samples were collected at over 100 stations throughout the Beaufort, Chukchi, and East Siberian seas, the Canada Basin, and the Amundsen Gulf. The cruises in 2000 made up two legs of the annual transit of the CCGS Sir Wilfred Laurier from its southern port in Victoria, BC to the Arctic. The first leg (2000–20) was a collaboration between the Fish- eries and Oceans Canada Ocean Climate Program (OCP), the Japan Marine Science and Technology Center (JAMSTEC), the University of Alaska Fairbanks (UAF), and the Univer- sity of Tennessee (UTenn). The second leg (2000–22) was funded by PERD and focused on carbon sequestration us- ing sediment traps in Amundsen Gulf. Parameters measured on all cruises from 1993 to 2000 include temperature, salin- ity, dissolved oxygen, nitrate, phosphate, silicate, and inor- ganic carbon. For the 1995 and 2000 cruises, the water col- umn tracer δ 18 O was also measured. Most of the typical suite of oceanographic data is included in the data reports listed above, but measurements of the inorganic carbon sys- tem (DIC and alkalinity) were not. All DIC samples were analyzed at IOS using a SOMMA system (Fig. 5) (Johnson et al., 1993). Alkalinity samples were analyzed at IOS from the same sample collected for DIC using a closed-cell, auto- mated potentiometric titration system (Millero et al., 1993). The precision of these methods for each cruise is listed in Table 2.
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Comparison of DNA Fingerprinting Methods for Use in Investigation of Type E Botulism Outbreaks in the Canadian Arctic

Comparison of DNA Fingerprinting Methods for Use in Investigation of Type E Botulism Outbreaks in the Canadian Arctic

SmaI and XhoI, respectively. These results are in agreement with other researchers who found that XhoI was more discrim- inatory than SmaI for the subtyping of C. botulinum type E in fish and fishery products from Finland and other areas (22, 29). However, three epidemiologically unrelated type E isolates could not be distinguished from outbreak strains using PFGE with both restriction enzymes. The PFGE pattern of the sed- iment isolate SOKR-23E1 originating from the Koksoak River, located approximately 150 km southwest of Kangiqsualujjuaq, was found to be identical to the PFGE patterns of the isolates from outbreak 1, which occurred in Kangiqsualujjuaq. The shoreline soil isolate SO325E1 and the single clinical isolate FE9508EPB, both originating from Tasiujaq, yielded the same SmaI or XhoI pulsotypes but were not epidemiologically related. Also, the epidemiologically unrelated isolate FE9909ERG shared the same PFGE pattern as the isolates from outbreak 4 in Inuvik (isolates FE0005EJT and MU0005EJT). Although these isolates were not epidemiologically related to the outbreak strains, they originated from the same region or northern village where the outbreaks occurred. The genetic biodiversity of C. botulinum type E in the Canadian Arctic is unknown, and further studies are needed to determine the distribution of subtypes involved in type E botulism outbreaks associated with the consumption of aged marine mammal meat. All strains belonging to C. botulinum group II were typeable by an automated ribotyping system using EcoRI, including the type E strains sensitive to DNA degrada- tion. These results differed from a previous study indicating that DNA degradation was the reason that only 2 of 13 type E strains were typeable with EcoRI (45). The different growth conditions and cell harvesting techniques between the two studies might have resulted in different DNA yields available for restriction digestion and hybridization. However, most EcoRI ribopatterns from C. botulinum group II strains were characterized by two fragments of approximately 3.2 and 2.1 kb. These results may indicate that most EcoRI restriction sites are conserved among C. botulinum group II and that these strains contained low copy numbers of rRNA operons and/or different rRNA operon copies located on fragments of similar molecular sizes.
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