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Sample records for grizzly bears highways

  1. Grizzly bear

    Science.gov (United States)

    Schwartz, C.C.; Miller, S.D.; Haroldson, M.A.; Feldhamer, G.; Thompson, B.; Chapman, J.

    2003-01-01

    The grizzly bear inspires fear, awe, and respect in humans to a degree unmatched by any other North American wild mammal. Like other bear species, it can inflict serious injury and death on humans and sometimes does. Unlike the polar bear (Ursus maritimus) of the sparsely inhabited northern arctic, however, grizzly bears still live in areas visited by crowds of people, where presence of the grizzly remains physically real and emotionally dominant. A hike in the wilderness that includes grizzly bears is different from a stroll in a forest from which grizzly bears have been purged; nighttime conversations around the campfire and dreams in the tent reflect the presence of the great bear. Contributing to the aura of the grizzly bear is the mixture of myth and reality about its ferocity. unpredictable disposition, large size, strength, huge canines, long claws, keen senses, swiftness, and playfulness. They share characteristics with humans such as generalist life history strategies. extended periods of maternal care, and omnivorous diets. These factors capture the human imagination in ways distinct from other North American mammals. Precontact Native American legends reflected the same fascination with the grizzly bear as modern stories and legends (Rockwell 1991).

  2. Eastern slopes grizzly bear project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-01-01

    The cumulative effects of human activities on the grizzly bears in the central Canadian Rockies are not well known. As a result, a project was initiated in 1994 to address the urgent requirement for accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of this study will be used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers are monitoring 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers involved in the project are working with representatives from Husky Oil and Talisman Energy on the sound development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over seven years indicated that the grizzly bears have few and infrequent offspring. Using the information gathered so far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears recover very slowly from high mortality, and also considering that the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The status of the population and habitat of the grizzly bear will be assessed upon the conclusion of the field research phase in 2001. Models will be updated using the data obtained during eight years and will assist in the understanding of complex variables that affect grizzly bears.

  3. Geophagy by yellowstone grizzly bears

    Science.gov (United States)

    Mattson, D.J.; Green, G.I.; Swalley, R.

    1999-01-01

    We documented 12 sites in the Yellowstone ecosystem where grizzly bears (Ursus arctos horribilis) had purposefully consumed soil (an activity known as geophagy). We also documented soil in numerous grizzly bear feces. Geophagy primarily occurred at sites barren of vegetation where surficial geology had been modified by geothermal activity. There was no evidence of ungulate use at most sites. Purposeful consumption of soil by bears peaked first from March to May and again from August to October, synchronous with peaks in consumption of ungulate meat and mushrooms. Geophageous soils were distinguished from ungulate mineral licks and soils in general by exceptionally high concentrations of potassium (K) and high concentrations of magnesium (Mg) and sulphur (S). Our results do not support the hypotheses that bears were consuming soil to detoxify secondary compounds in grazed foliage, as postulated for primates, or to supplement dietary sodium, as known for ungulates. Our results suggest that grizzly bears could have been consuming soil as an anti-diarrheal.

  4. Myrmecophagy by Yellowstone grizzly bears

    Science.gov (United States)

    Mattson, D.J.

    2001-01-01

    I used data collected during a study of radio-marked grizzly bears (Ursus arctos horribilis) in the Yellowstone region from 1977 to 1992 to investigate myrmecophagy by this population. Although generally not an important source of energy for the bears (averaging 8 mm long) nested in logs over small ants (6 mm long) nested under stones. Optimal conditions for consumption of ants occurred on the warmest sites with ample substrate suitable for ant nests. For ants in mounds, this occurred at low elevations at non-forested sites. For ants in logs, this occurred at low elevations or on southerly aspects where there was abundant, large-diameter, well-decomposed woody debris under an open forest canopy. Grizzly bears selected moderately decomposed logs 4a??5 dm in diameter at midpoint. Ants will likely become a more important food for Yellowstone's grizzly bears as currently important foods decline, owing to disease and warming of the regional climate.

  5. Eastern slopes grizzly bear project : project update

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    This report updates a study to examine the cumulative effects of human activities on the grizzly bears in the central Canadian Rockies. The project was initiated in 1994 to acquire accurate scientific information on the habitat and populations of grizzly bears in the area of the Banff National Park and Kananaskis Country. This area is probably the most heavily used and developed area where the grizzly still survives. The information gathered throughout the course of the study is used to better protect and manage the bears and other sensitive carnivores in the region. Using telemetry, researchers monitored 25 grizzly bears which were radio-collared in a 22,000 square-kilometer area in the upper Bow Valley drainage of the eastern Alberta slopes. The researchers worked with representatives from Husky Oil and Rigel Energy on the development of the Moose Mountain oil and gas field without adversely affecting the grizzly bear population. Information collected over eight years indicates that the grizzly bears have few and infrequent offspring. Using the information gathered thus far, the location of the Moose Mountain to Jumping Pound pipeline was carefully selected, since the bears suffer from high mortality, and the food and cover had already been compromised by the high number of roads, trails and other human activities in the area. The research concluded in November 2001 provides sufficient information to accurately asses the status of the grizzly bear population and habitat. The data will be analyzed and integrated in 2002 into models that reflect the variables affecting grizzly bears and a final report will be published.

  6. North Cascades Grizzly Bear Ecosystem Evaluation

    Data.gov (United States)

    Oak Ridge National Laboratory — We conducted a 6-year evaluation of the North Cascades Grizzly Bear Ecosystem (NCGBE) in north-central Washington to determine the suitability of the area to support...

  7. Yellowstone grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 2006

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.; West, Karrie K.

    2007-01-01

    The contents of this Annual Report summarize results of monitoring and research from the 2006 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions.

  8. Yellowstone grizzly bear investigations: Annual report of the Interagency Grizzly Bear Study Team, 2001

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.

    2001-01-01

    The contents of this Annual Report summarize results of monitoring and research from the 2001 field season. The report also contains a summary of nuisance grizzly bear (Ursus arctos horribilis) management actions.

  9. The paradigm of grizzly bear restoration in North America

    Science.gov (United States)

    Schwartz, C. C.; Maehr, David S.; Noss, Reed F.; Larkin, J.L.

    2002-01-01

    Grizzly bear restoration and recovery is a controversial, highly politicized process. By 1959, when the Craigheads began their pioneering work on Yellowstone grizzly bears, the species had been reduced to a remnant of its historic range. Prior to the colonization of North America by Europeans, the grizzly lived in relatively pristine habitats with aboriginal Native Americans. As civilization expanded, humans changed the face of the landscape, converting grizzly bear habitat to farms and ranches. People killed grizzlies to protect livestock and eliminate a perceived threat to human safety. In concert, habitat loss and direct human-caused mortality had effectively eliminated the grizzly from 95 percent of its historic range in the conterminous United States by the 1920s (Servheen 1989). Grizzly bear numbers had been reduced nearly 98 percent by 1975 when the species was listed as threatened under the Endangered Species Act (ESA) (USFWS 1993).

  10. Demography of the Yellowstone grizzly bears

    Science.gov (United States)

    Pease, C.M.; Mattson, D.J.

    1999-01-01

    We undertook a demographic analysis of the Yellowstone grizzly bears (Ursus arctos) to identify critical environmental factors controlling grizzly bear vital rates, and thereby to help evaluate the effectiveness of past management and to identify future conservation issues. We concluded that, within the limits of uncertainty implied by the available data and our methods of data analysis, the size of the Yellowstone grizzly bear population changed little from 1975 to 1995. We found that grizzly bear mortality rates are about double in years when the whitebark pine crop fails than in mast years, and that the population probably declines when the crop fails and increases in mast years. Our model suggests that natural variation in whitebark pine crop size over the last two decades explains more of the perceived fluctuations in Yellowstone grizzly population size than do other variables. Our analysis used demographic data from 202 radio-telemetered bears followed between 1975 and 1992 and accounted for whitebark pine (Pinus albicaulis) crop failures during 1993-1995. We used a maximum likelihood method to estimate demographic parameters and used the Akaike Information Criteria to judge the significance of various independent variables. We identified no independent variables correlated with grizzly bear fecundity. In order of importance, we found that grizzly bear mortality rates are correlated with season, whitebark pine crop size (mast vs. nonmast year), sex, management-trapping status (never management-trapped vs. management-trapped once or more), and age. The mortality rate of bears that were management-trapped at least once was almost double that of bears that were never management-trapped, implying a source/sink (i.e., never management-trapped/management-trapped) structure. The rate at which bears move between the source and sink, estimated as the management-trapping rate (h), is critical to estimating the finite rate of increase, I>I?. We quantified h by

  11. Grizzly bear diet shifting on reclaimed mines

    Directory of Open Access Journals (Sweden)

    Bogdan Cristescu

    2015-07-01

    Full Text Available Industrial developments and reclamation change habitat, possibly altering large carnivore food base. We monitored the diet of a low-density population of grizzly bears occupying a landscape with open-pit coal mines in Canada. During 2009–2010 we instrumented 10 bears with GPS radiocollars and compared their feeding on reclaimed coal mines and neighboring Rocky Mountains and their foothills. In addition, we compared our data with historical bear diet for the same population collected in 2001–2003, before extensive mine reclamation occurred. Diet on mines (n=331 scats was dominated by non-native forbs and graminoids, while diets in the Foothills and Mountains consisted primarily of ungulates and Hedysarum spp. roots respectively, showing diet shifting with availability. Field visitation of feeding sites (n=234 GPS relocation clusters also showed that ungulates were the main diet component in the Foothills, whereas on reclaimed mines bears were least carnivorous. These differences illustrate a shift to feeding on non-native forbs while comparisons with historical diet reveal emergence of elk as an important bear food. Food resources on reclaimed mines attract bears from wilderness areas and bears may be more adaptable to landscape change than previously thought. The grizzly bear’s ready use of mines cautions the universal view of this species as umbrella indicative of biodiversity.

  12. Dietary breadth of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Gunther, Kerry A.; Shoemaker, Rebecca; Frey, Kevin L.; Haroldson, Mark A.; Cain, Steven L; van Manen, Frank T.; Fortin, Jennifer K.

    2014-01-01

    Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE) are opportunistic omnivores that eat a great diversity of plant and animal species. Changes in climate may affect regional vegetation, hydrology, insects, and fire regimes, likely influencing the abundance, range, and elevational distribution of the plants and animals consumed by GYE grizzly bears. Determining the dietary breadth of grizzly bears is important to document future changes in food resources and how those changes may affect the nutritional ecology of grizzlies. However, no synthesis exists of all foods consumed by grizzly bears in the GYE. We conducted a review of available literature and compiled a list of species consumed by grizzly bears in the GYE. We documented >266 species within 200 genera from 4 kingdoms, including 175 plant, 37 invertebrate, 34 mammal, 7 fungi, 7 bird, 4 fish, 1 amphibian, and 1 algae species as well as 1 soil type consumed by grizzly bears. The average energy values of the ungulates (6.8 kcal/g), trout (Oncorhynchus spp., 6.1 kcal/g), and small mammals (4.5 kcal/g) eaten by grizzlies were higher than those of the plants (3.0 kcal/g) and invertebrates (2.7 kcal/g) they consumed. The most frequently detected diet items were graminoids, ants (Formicidae), whitebark pine seeds (Pinus albicaulis), clover (Trifolium spp.), and dandelion (Taraxacum spp.). The most consistently used foods on a temporal basis were graminoids, ants, whitebark pine seeds, clover, elk (Cervus elaphus), thistle (Cirsium spp.), and horsetail (Equisetum spp.). Historically, garbage was a significant diet item for grizzlies until refuse dumps were closed. Use of forbs increased after garbage was no longer readily available. The list of foods we compiled will help managers of grizzly bears and their habitat document future changes in grizzly bear food habits and how bears respond to changing food resources.

  13. Grizzly West: A Failed Attempt to Reintroduce Grizzly Bears in the Mountain West

    Directory of Open Access Journals (Sweden)

    Douglas M. Richardson

    2016-05-01

    Full Text Available Reviewed: Grizzly West: A Failed Attempt to Reintroduce Grizzly Bears in the Mountain West. By Michael M. Dax. Lincoln, NE: University of Nebraska Press, 2015. x + 289 pp. US$ 37.50. ISBN 978-0-8032-6673-5.

  14. Effects of exotic species on Yellowstone's grizzly bears

    Science.gov (United States)

    Reinhart, D.P.; Haroldson, Mark A.; Mattson, D.J.; Gunther, Kerry A.

    2001-01-01

    Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but use of this food by bears often leads to conflicts with humans and subsequent increases in bear mortality. Lake trout, blister rust, and brucellosis diminish grizzly bears foods. Lake trout prey on native cutthroat trout (Oncorhynchus clarkii) in Yellowstone Lake; white pine blister rust has the potential to destroy native whitebark pine (Pinus albicaulis) stands; and management response to bovine brucellosis, a disease found in the Yellowstone bison (Bison bison) and elk (Cervus elaphus), could reduce populations of these 2 species. Exotic species will likely cause more harm than good for Yellowstone grizzly bears. Managers have few options to mitigate or contain the impacts of exotics on Yellowstones grizzly bears. Moreover, their potential negative impacts have only begun to unfold. Exotic species may lead to the loss of substantial highquality grizzly bear foods, including much of the bison, trout, and pine seeds that Yellowstone grizzly bears currently depend upon.

  15. Grizzly bear habitat selection is scale dependent.

    Science.gov (United States)

    Ciarniello, Lana M; Boyce, Mark S; Seip, Dale R; Heard, Douglas C

    2007-07-01

    The purpose of our study is to show how ecologists' interpretation of habitat selection by grizzly bears (Ursus arctos) is altered by the scale of observation and also how management questions would be best addressed using predetermined scales of analysis. Using resource selection functions (RSF) we examined how variation in the spatial extent of availability affected our interpretation of habitat selection by grizzly bears inhabiting mountain and plateau landscapes. We estimated separate models for females and males using three spatial extents: within the study area, within the home range, and within predetermined movement buffers. We employed two methods for evaluating the effects of scale on our RSF designs. First, we chose a priori six candidate models, estimated at each scale, and ranked them using Akaike Information Criteria. Using this method, results changed among scales for males but not for females. For female bears, models that included the full suite of covariates predicted habitat use best at each scale. For male bears that resided in the mountains, models based on forest successional stages ranked highest at the study-wide and home range extents, whereas models containing covariates based on terrain features ranked highest at the buffer extent. For male bears on the plateau, each scale estimated a different highest-ranked model. Second, we examined differences among model coefficients across the three scales for one candidate model. We found that both the magnitude and direction of coefficients were dependent upon the scale examined; results varied between landscapes, scales, and sexes. Greenness, reflecting lush green vegetation, was a strong predictor of the presence of female bears in both landscapes and males that resided in the mountains. Male bears on the plateau were the only animals to select areas that exposed them to a high risk of mortality by humans. Our results show that grizzly bear habitat selection is scale dependent. Further, the

  16. Foothills model forest grizzly bear study : project update

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-01-01

    This report updates a five year study launched in 1999 to ensure the continued healthy existence of grizzly bears in west-central Alberta by integrating their needs into land management decisions. The objective was to gather better information and to develop computer-based maps and models regarding grizzly bear migration, habitat use and response to human activities. The study area covers 9,700 square km in west-central Alberta where 66 to 147 grizzly bears exist. During the first 3 field seasons, researchers captured and radio collared 60 bears. Researchers at the University of Calgary used remote sensing tools and satellite images to develop grizzly bear habitat maps. Collaborators at the University of Washington used trained dogs to find bear scat which was analyzed for DNA, stress levels and reproductive hormones. Resource Selection Function models are being developed by researchers at the University of Alberta to identify bear locations and to see how habitat is influenced by vegetation cover and oil, gas, forestry and mining activities. The health of the bears is being studied by researchers at the University of Saskatchewan and the Canadian Cooperative Wildlife Health Centre. The study has already advanced the scientific knowledge of grizzly bear behaviour. Preliminary results indicate that grizzlies continue to find mates, reproduce and gain weight and establish dens. These are all good indicators of a healthy population. Most bear deaths have been related to poaching. The study will continue for another two years. 1 fig.

  17. Whitebark pine, grizzly bears, and red squirrels

    Science.gov (United States)

    Mattson, D.J.; Kendall, K.C.; Reinhart, D.P.; Tomback, D.F.; Arno, S.F.; Keane, R.E.

    2001-01-01

    Appropriately enough, much of this book is devoted to discussing management challenges and techniques. However, the impetus for action—the desire to save whitebark pine (Pinus albicaulis)—necessarily arises from the extent to which we cherish it for its beauty and its connections with other things that we value. Whitebark pine is at the hub of a fascinating web of relationships. It is the stuff of great stories (cf. Quammen 1994). One of the more interesting of these stories pertains to the dependence of certain grizzly bear (Ursus arctos horribilis) populations on its seeds, and the role that red squirrels (Tamiasciurus hudsonicus) play as an agent of transfer between tree and bear.

  18. Grizzly bears and mining in the Cheviot region

    Energy Technology Data Exchange (ETDEWEB)

    Symbaluk, M.; Archibald, T. [Foothills Research Inst., Hinton, AB (Canada)

    2008-07-01

    This presentation described a grizzly bear research program conducted by the Foothill Research Institute at the Cheviot mine. The research program uses a satellite land classification protocol and remote sensing tools to map and identify the grizzly bear habitat. Modelling is also conducted to predict bear probabilities. Global information systems (GIS) are used to evaluate bear responses to human activities. Grizzly bear health and wellness is also assessed as part of the programs. Land maps are combined with global positioning systems (GPS) and resource selection function (RSF) models in order to map grizzly bear distribution. Data obtained from the program is used to inform decision-making and support policy development. Previous studies predicted that the grizzly bear population would disappear from the Cheviot mine area after 20 years of its being in operation. The research program provided real data to test predictions made during previous environmental assessments. Grizzly bear populations have actually increased in the mining area. It was concluded that the bears have moved more freely through industrial landscapes than previously predicted. tabs., figs.

  19. How much lox is a grizzly bear worth?

    Science.gov (United States)

    Chase, Jonathan

    2012-01-01

    Using grizzly bears as surrogates for "salmon ecosystem" function, the authors develop a generalizable ecosystem-based management framework that enables decision makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish.

  20. Trophic cascades from wolves to grizzly bears in Yellowstone.

    Science.gov (United States)

    Ripple, William J; Beschta, Robert L; Fortin, Jennifer K; Robbins, Charles T

    2014-01-01

    We explored multiple linkages among grey wolves (Canis lupus), elk (Cervus elaphus), berry-producing shrubs and grizzly bears (Ursus arctos) in Yellowstone National Park. We hypothesized competition between elk and grizzly bears whereby, in the absence of wolves, increases in elk numbers would increase browsing on berry-producing shrubs and decrease fruit availability to grizzly bears. After wolves were reintroduced and with a reduced elk population, we hypothesized there would be an increase in the establishment of berry-producing shrubs, such as serviceberry (Amelanchier alnifolia), which is a major berry-producing plant. We also hypothesized that the percentage fruit in the grizzly bear diet would be greater after than before wolf reintroduction. We compared the frequency of fruit in grizzly bear scats to elk densities prior to wolf reintroduction during a time of increasing elk densities (1968-1987). For a period after wolf reintroduction, we calculated the percentage fruit in grizzly bear scat by month based on scats collected in 2007-2009 (n = 778 scats) and compared these results to scat data collected before wolf reintroduction. Additionally, we developed an age structure for serviceberry showing the origination year of stems in a northern range study area. We found that over a 19-year period, the percentage frequency of fruit in the grizzly diet (6231 scats) was inversely correlated (P wolves and other large carnivores on elk, a reduced and redistributed elk population, decreased herbivory and increased production of plant-based foods that may aid threatened grizzly bears. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

  1. Grizzly bear nutrition and ecology studies in Yellowstone National Park

    Science.gov (United States)

    Robbins, Charles T.; Schwartz, Charles C.; Gunther, Kerry A.; Servheen, Christopher

    2006-01-01

    T HE CHANCE TO SEE a wild grizzly bear is often the first or second reason people give for visiting Yellow - stone National Park. Public interest in bears is closely coupled with a desire to perpetuate this wild symbol of the American West. Grizzly bears have long been described as a wilderness species requiring large tracts of undisturbed habitat. However, in today’s world, most grizzly bears live in close proximity to humans (Schwartz et al. 2003). Even in Yellowstone National Park, the impacts of humans can affect the long-term survival of bears (Gunther et al. 2002). As a consequence, the park has long supported grizzly bear research in an effort to understand these impacts. Most people are familiar with what happened when the park and the State of Montana closed open-pit garbage dumps in the late 1960s and early 1970s, when at least 229 bears died as a direct result of conflict with humans. However, many may not be as familiar with the ongoing changes in the park’s plant and animal communities that have the potential to further alter the park’s ability to support grizzly bears.

  2. Consumption of pondweed rhizomes by Yellowstone grizzly bears

    Science.gov (United States)

    Mattson, D.J.; Podruzny, S.R.; Haroldson, M.A.

    2005-01-01

    Pondweeds (Potamogeton spp.) are common foods of waterfowl throughout the Northern Hemisphere. However, consumption of pondweeds by bears has been noted only once, in Russia. We documented consumption of pondweed rhizomes by grizzly bears (Ursus arctos) in the Yellowstone region, 1977-96, during investigations of telemetry locations obtained from 175 radiomarked bears. We documented pondweed excavations at 25 sites and detected pondweed rhizomes in 18 feces. We observed grizzly bears excavating and consuming pondweed on 2 occasions. All excavations occurred in wetlands that were inundated during and after snowmelt, but dry by late August or early September of most years. These wetlands were typified by the presence of inflated sedge (Carex vesicaria) and occurred almost exclusively on plateaus of Pliocene-Pleistocene detrital sediments or volcanic rhyolite flows. Bears excavated wetlands with pondweeds when they were free of standing water, most commonly during October and occasionally during spring prior to the onset of terminal snowmelt. Most excavations were about 4.5 cm deep, 40 cubic decimeter (dm3) in total volume, and targeted the thickened pondweed rhizomes. Starch content of rhizomes collected near grizzly bear excavations averaged 28% (12% SD; n = 6). These results add to the documented diversity of grizzly bear food habits and, because pondweed is distributed circumboreally, also raise the possibility that consumption of pondweed by grizzly bears has been overlooked in other regions.

  3. Density dependence, whitebark pine, and vital rates of grizzly bears

    Science.gov (United States)

    van Manen, Frank T.; Haroldson, Mark A.; Bjornlie, Daniel D; Ebinger, Michael R.; Thompson, Daniel J.; Costello, Cecily M; White, Gary C.

    2016-01-01

    Understanding factors influencing changes in population trajectory is important for effective wildlife management, particularly for populations of conservation concern. Annual population growth of the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem, USA has slowed from 4.2–7.6% during 1983–2001 to 0.3–2.2% during 2002–2011. Substantial changes in availability of a key food source and bear population density have occurred. Whitebark pine (Pinus albicaulis), the seeds of which are a valuable but variable fall food for grizzly bears, has experienced substantial mortality primarily due to a mountain pine beetle (Dendroctonus ponderosae) outbreak that started in the early 2000s. Positive growth rates of grizzly bears have resulted in populations reaching high densities in some areas and have contributed to continued range expansion. We tested research hypotheses to examine if changes in vital rates detected during the past decade were more associated with whitebark pine decline or, alternatively, increasing grizzly bear density. We focused our assessment on known-fate data to estimate survival of cubs-of-the-year (cubs), yearlings, and independent bears (≥2 yrs), and reproductive transition of females from having no offspring to having cubs. We used spatially and temporally explicit indices for grizzly bear density and whitebark pine mortality as individual covariates. Models indicated moderate support for an increase in survival of independent male bears over 1983–2012, whereas independent female survival did not change. Cub survival, yearling survival, and reproductive transition from no offspring to cubs all changed during the 30-year study period, with lower rates evident during the last 10–15 years. Cub survival and reproductive transition were negatively associated with an index of grizzly bear density, indicating greater declines where bear densities were higher. Our analyses did not support a similar relationship for the

  4. Grizzly bear corticosteroid binding globulin: Cloning and serum protein expression.

    Science.gov (United States)

    Chow, Brian A; Hamilton, Jason; Alsop, Derek; Cattet, Marc R L; Stenhouse, Gordon; Vijayan, Mathilakath M

    2010-06-01

    Serum corticosteroid levels are routinely measured as markers of stress in wild animals. However, corticosteroid levels rise rapidly in response to the acute stress of capture and restraint for sampling, limiting its use as an indicator of chronic stress. We hypothesized that serum corticosteroid binding globulin (CBG), the primary transport protein for corticosteroids in circulation, may be a better marker of the stress status prior to capture in grizzly bears (Ursus arctos). To test this, a full-length CBG cDNA was cloned and sequenced from grizzly bear testis and polyclonal antibodies were generated for detection of this protein in bear sera. The deduced nucleotide and protein sequences were 1218 bp and 405 amino acids, respectively. Multiple sequence alignments showed that grizzly bear CBG (gbCBG) was 90% and 83% identical to the dog CBG nucleotide and amino acid sequences, respectively. The affinity purified rabbit gbCBG antiserum detected grizzly bear but not human CBG. There were no sex differences in serum total cortisol concentration, while CBG expression was significantly higher in adult females compared to males. Serum cortisol levels were significantly higher in bears captured by leg-hold snare compared to those captured by remote drug delivery from helicopter. However, serum CBG expression between these two groups did not differ significantly. Overall, serum CBG levels may be a better marker of chronic stress, especially because this protein is not modulated by the stress of capture and restraint in grizzly bears.

  5. Cannibalism and predation on black bears by grizzly bears in the Yellowstone ecosystem, 1975-1990

    Science.gov (United States)

    Mattson, D.J.; Knight, R.R.; Blanchard, B.M.

    1992-01-01

    We documented one instance of an adult male grizzly bear preying upon a black bear and four instances where circumstantial evidence suggested that grizzly bears (two cubs-of-the-year, one yearling female that was injured, and one adult male) had been preyed upon by conspecifics. We also examined feces of grizzly bears for bear remains. Remains of bears tended to be more common in spring feces and did not differ in frequency between early and late years of the study. Our observations generally support existing hypotheses concerning cannibalism among bears.

  6. Chromatographic (TLC) differentiation of grizzly bear and black bear scats

    Science.gov (United States)

    Picton, Harold D.; Kendall, Katherine C.

    1994-01-01

    While past work concluded that thin-layer chromatography (TLC) was inadequate for the separation of grizzly (Ursus arctos horribilis) and black bear (U. americanus) scats, our study found differences adequate for species separation. A key was constructed using 19 of 40 data points recorded on each(N)=356 profiles of 178) know-species scat. Accuracy was best for late summer scats (94%). Methods for specimen preparation, analysis, and reading the TLC profiles are discussed. Factors involved in scat variation were tested.

  7. Habitat use and behavior of grizzly bears in the Arctic National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report covers habitat use and behavior of grizzly bears in the Arctic National Wildlife Refuge. Habitat use and behavior of grizzly bears (Ursus arctos) wer2...

  8. Parasites in grizzly bears from the central Canadian Arctic.

    Science.gov (United States)

    Gau, R J; Kutz, S; Elkin, B T

    1999-07-01

    Standardized flotation techniques were used to survey 56 grizzly bear (Ursus arctos) fecal samples for parasites. The samples were collected during the spring and autumn of 1995 and 1996 in the central Arctic of the Northwest Territories (Canada). Parasites of the genera Nematodirus, gastrointestinal coccidia, and an unidentified first stage protostrongylid larva are reported for the first time from grizzly bear feces in North America. Parasites of the genera Diphyllobothrium and Baylisascaris also were collected. Prevalence of gastrointestinal parasites were significantly different between the spring and autumn seasons (31% and 58% respectively). Thus, we provide evidence supporting the theory that bears void gastrointestinal parasites before hibernation.

  9. Grizzly bear density in Glacier National Park, Montana

    Science.gov (United States)

    Kendall, K.C.; Stetz, J.B.; Roon, David A.; Waits, L.P.; Boulanger, J.B.; Paetkau, David

    2008-01-01

    We present the first rigorous estimate of grizzly bear (Ursus arctos) population density and distribution in and around Glacier National Park (GNP), Montana, USA. We used genetic analysis to identify individual bears from hair samples collected via 2 concurrent sampling methods: 1) systematically distributed, baited, barbed-wire hair traps and 2) unbaited bear rub trees found along trails. We used Huggins closed mixture models in Program MARK to estimate total population size and developed a method to account for heterogeneity caused by unequal access to rub trees. We corrected our estimate for lack of geographic closure using a new method that utilizes information from radiocollared bears and the distribution of bears captured with DNA sampling. Adjusted for closure, the average number of grizzly bears in our study area was 240.7 (95% CI = 202–303) in 1998 and 240.6 (95% CI = 205–304) in 2000. Average grizzly bear density was 30 bears/1,000 km2, with 2.4 times more bears detected per hair trap inside than outside GNP. We provide baseline information important for managing one of the few remaining populations of grizzlies in the contiguous United States.

  10. 78 FR 29774 - Endangered and Threatened Wildlife and Plants; Draft Revised Supplement to the Grizzly Bear...

    Science.gov (United States)

    2013-05-21

    ... the Grizzly Bear Recovery Plan; Extension of Public Comment Period AGENCY: Fish and Wildlife Service... Grizzly Bear Recovery Plan in the greater Yellowstone area. If you have previously submitted comments... Revised Supplement to the Grizzly Bear Recovery Plan is available at...

  11. 78 FR 17708 - Endangered and Threatened Wildlife and Plants; Draft Revised Supplement to the Grizzly Bear...

    Science.gov (United States)

    2013-03-22

    ... the Grizzly Bear Recovery Plan AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of document... availability of a draft Revised Supplement to the Grizzly Bear Recovery Plan. Specifically, this supplement..., Grizzly bears (Ursus arctos horribilis) are federally listed as threatened under the Endangered...

  12. Predicting grizzly bear density in western North America.

    Directory of Open Access Journals (Sweden)

    Garth Mowat

    Full Text Available Conservation of grizzly bears (Ursus arctos is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  13. Predicting grizzly bear density in western North America.

    Science.gov (United States)

    Mowat, Garth; Heard, Douglas C; Schwarz, Carl J

    2013-01-01

    Conservation of grizzly bears (Ursus arctos) is often controversial and the disagreement often is focused on the estimates of density used to calculate allowable kill. Many recent estimates of grizzly bear density are now available but field-based estimates will never be available for more than a small portion of hunted populations. Current methods of predicting density in areas of management interest are subjective and untested. Objective methods have been proposed, but these statistical models are so dependent on results from individual study areas that the models do not generalize well. We built regression models to relate grizzly bear density to ultimate measures of ecosystem productivity and mortality for interior and coastal ecosystems in North America. We used 90 measures of grizzly bear density in interior ecosystems, of which 14 were currently known to be unoccupied by grizzly bears. In coastal areas, we used 17 measures of density including 2 unoccupied areas. Our best model for coastal areas included a negative relationship with tree cover and positive relationships with the proportion of salmon in the diet and topographic ruggedness, which was correlated with precipitation. Our best interior model included 3 variables that indexed terrestrial productivity, 1 describing vegetation cover, 2 indices of human use of the landscape and, an index of topographic ruggedness. We used our models to predict current population sizes across Canada and present these as alternatives to current population estimates. Our models predict fewer grizzly bears in British Columbia but more bears in Canada than in the latest status review. These predictions can be used to assess population status, set limits for total human-caused mortality, and for conservation planning, but because our predictions are static, they cannot be used to assess population trend.

  14. Potential energetic effects of mountain climbers on foraging grizzly bears

    Science.gov (United States)

    White, D.; Kendall, K.C.; Picton, H.D.

    1999-01-01

    Most studies of the effects of human disturbance on grizzly bears (Ursus arctos horribilis) have not quantified the energetic effects of such interactions. In this study, we characterized activity budgets of adult grizzly bears as they foraged on aggregations of adult army cutworm moths (Euxoa auxiliaris) in the alpine of Glacier National Park, Montana, during 1992, 1994, and 1995. We compared the activity budgets of climber-disturbed bears to those of undisturbed bears to estimate the energetic impact of climber disturbance. When bears detected climbers, they subsequently spent 53% less time foraging on moths, 52% more time moving within the foraging area, and 23% more time behaving aggressively, compared to when they were not disturbed. We estimated that grizzly bears could consume approximately 40,000 moths/day or 1,700 moths/hour. At 0.44 kcal/moth, disruption of moth feeding cost bears approximately 12 kcal/minute in addition to the energy expended in evasive maneuvers and defensive behaviors. To reduce both climber interruption of bear foraging and the potential for aggressive bear-human encounters, we recommend routing climbers around moth sites used by bears or limiting access to these sites during bear-use periods.

  15. Coefficients of Productivity for Yellowstone's Grizzly Bear Habitat

    Science.gov (United States)

    Mattson, David John; Barber, Kim; Maw, Ralene; Renkin, Roy

    2004-01-01

    This report describes methods for calculating coefficients used to depict habitat productivity for grizzly bears in the Yellowstone ecosystem. Calculations based on these coefficients are used in the Yellowstone Grizzly Bear Cumulative Effects Model to map the distribution of habitat productivity and account for the impacts of human facilities. The coefficients of habitat productivity incorporate detailed information that was collected over a 20-year period (1977-96) on the foraging behavior of Yellowstone's bears and include records of what bears were feeding on, when and where they fed, the extent of that feeding activity, and relative measures of the quantity consumed. The coefficients also incorporate information, collected primarily from 1986 to 1992, on the nutrient content of foods that were consumed, their digestibility, characteristic bite sizes, and the energy required to extract and handle each food. Coefficients were calculated for different time periods and different habitat types, specific to different parts of the Yellowstone ecosystem. Stratifications included four seasons of bear activity (spring, estrus, early hyperphagia, late hyperphagia), years when ungulate carrion and whitebark pine seed crops were abundant versus not, areas adjacent to (bear activity in each region, habitat type, and time period were incorporated into calculations, controlling for the effects of proximity to human facilities. The coefficients described in this report and associated estimates of grizzly bear habitat productivity are unique among many efforts to model the conditions of bear habitat because calculations include information on energetics derived from the observed behavior of radio-marked bears.

  16. How much lox is a grizzly bear worth?

    Directory of Open Access Journals (Sweden)

    Jonathan Chase

    Full Text Available Using grizzly bears as surrogates for "salmon ecosystem" function, the authors develop a generalizable ecosystem-based management framework that enables decision makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish.

  17. Science and management of Rocky Mountain grizzly bears

    Science.gov (United States)

    Mattson, D.J.; Herrero, S.; Wright, R.G.; Pease, C.M.

    1996-01-01

    The science and management of grizzly bears (Ursus arctos horribilis) in the Rocky Mountains of North America have spawned considerable conflict and controversy. Much of this can be attributed to divergent public values, but the narrow perceptions and incomplete and fragmented problem definitions of those involved have exacerbated an inherently difficult situation. We present a conceptual model that extends the traditional description of the grizzly bear conservation system to include facets of the human domain such as the behavior of managers, elected officials, and the public. The model focuses on human-caused mortality, the key determinant of grizzly bear population growth in this region and the interactions and feedback loops among humans that have a major potential influence on bear mortality. We also briefly evaluate existing information and technical methods relevant to understanding this complex human-biophysical system. We observe not only that the extant knowledge is insufficient for prediction (and in some cases for description), but also that traditional positivistic science alone is not adequate for dealing with the problems of grizzly bear conservation. We recommend changes in science and management that could improve learning and responsiveness among the involved individuals and organizations, clarify some existing uncertainty, and thereby increase the effectiveness of grizzly bear conservation and management. Although adaptive management is a promising approach, we point out some keya??as yet unfulfilleda??contingencies for implementation of a method such as this one that relies upon social processes and structures that promote open learning and flexibility in all facets of the policy process.

  18. Response of Yellowstone grizzly bears to changes in food resources: A synthesis. Final report to the Interagency Grizzly Bear Committee and Yellowstone Ecosystem Subcommittee

    Science.gov (United States)

    ,; van Manen, Frank T.; Cecily M, Costello; Haroldson, Mark A.; Daniel D, Bjornlie; Michael R, Ebinger; Kerry A, Gunther; Mary Frances, Mahalovich; Daniel J, Thompson; Megan D, Higgs; Irvine, Kathryn M.; Kristin, Legg; Daniel, Tyers; Landenburger, Lisa; Steven L, Cain; Frey, Kevin L.; Aber, Bryan C.; Schwartz, Charles C.

    2013-01-01

    The Yellowstone grizzly bear (Ursus arctos) was listed as a threatened species in 1975 (Federal Register 40 FR:31734-31736). Since listing, recovery efforts have focused on increasing population size, improving habitat security, managing bear mortalities, and reducing bear-human conflicts. The Interagency Grizzly Bear Committee (IGBC; partnership of federal and state agencies responsible for grizzly bear recovery in the lower 48 states) and its Yellowstone Ecosystem Subcommitte (YES; federal, state, county, and tribal partners charged with recovery of grizzly bears in the Greater Yelowston Ecosystem [GYE]) tasked the Interagency Grizzly Bear Study Team to provide information and further research relevant to three concerns arising from the 9th Circuit Court of Appeals November 2011 decision: 1) the ability of grizzly bears as omnivores to find alternative foods to whitebark pine seeds; 2) literature to support their conclusions; and 3) the non-intuitive biological reality that impacts can occur to individuals without causing the overall population to decline. Specifically, the IGBC and YES requested a comprehensive synthesis of the current state of knowledge regarding whitebark pinbe decline and individual and population-level responses of grizzly bears to changing food resources in the GYE. This research was particularly relevant to grizzly bear conservation given changes in the population trajectory observed during the last decade.

  19. Acquired arteriovenous fistula in a grizzly bear (Ursus arctos horribilis).

    Science.gov (United States)

    Tuttle, Allison D; MacLean, Robert A; Linder, Keith; Cullen, John M; Wolfe, Barbara A; Loomis, Michael

    2009-03-01

    A captive adult male grizzly bear (Ursus arctos horribilis) was evaluated due to multifocal wounds of the skin and subcutaneous tissues sustained as a result of trauma from another grizzly bear. On presentation, one lesion that was located in the perineal region seemed to be a deep puncture with purple tissue protruding from it. This perineal wound did not heal in the same manner or rate as did the other wounds. Twenty-five days after initial detection, substantial active hemorrhage from the lesion occurred and necessitated anesthesia for examination of the bear. The entire lesion was surgically excised, which later proved curative. An acquired arteriovenous fistula was diagnosed via histopathology. Arteriovenous fistulas can develop after traumatic injury and should be considered as a potential complication in bears with nonhealing wounds.

  20. MEDULLOBLASTOMA IN A GRIZZLY BEAR (URSUS ARCTOS HORRIBLIS).

    Science.gov (United States)

    Mitchell, Jeffrey W; Thomovsky, Stephanie A; Chen, Annie V; Layton, Arthur W; Haldorson, Gary; Tucker, Russell L; Roberts, Gregory

    2015-09-01

    A 3-yr-old female spayed grizzly bear (Ursus arctos horribilis) was evaluated for seizure activity along with lethargy, inappetence, dull mentation, and aggressive behavior. Magnetic resonance (MR) examination of the brain revealed a contrast-enhanced right cerebellar mass with multifocal smaller nodules located in the left cerebellum, thalamus, hippocampus, and cerebrum with resultant obstructive hydrocephalus. Cerebrospinal fluid analysis revealed mild mononuclear pleocytosis, with differentials including inflammatory versus neoplastic processes. Blood and cerebrospinal fluid were also submitted for polymerase chain reaction and agar gel immunodiffusion to rule out infectious causes of meningitis/encephalitis. While awaiting these results, the bear was placed on steroid and antibiotic therapy. Over the next week, the bear deteriorated; she died 1 wk after MR. A complete postmortem examination, including immunohistochemisty, revealed the cerebellar mass to be a medulloblastoma. This is the only case report, to the authors' knowledge, describing a medulloblastoma in a grizzly bear.

  1. Trend of the Yellowstone Grizzly Bear Population

    Directory of Open Access Journals (Sweden)

    L. L. Eberhardt

    2010-01-01

    Full Text Available Yellowstone's grizzlies (Ursus arctos have been studied for more than 40 years. Radiotelemetry has been used to obtain estimates of the rate of increase of the population, with results reported by Schwartz et al. (2006. Counts of females with cubs-of-the-year “unduplicated” also provide an index of abundance and are the primary subject of this report. An exponential model was fitted to n=24 such counts, using nonlinear leastsquares. Estimates of the rate of increase, r, were about 0.053. 95% confidence intervals, were obtained by several different methods, and all had lower limits substantially above zero, indicating that the population has been increasing steadily, in contrast to the results of Schwartz et al. (2006, which could not exclude a decreasing population. The grizzly data have been repeatedly mis-used in current literature for reasons explained here.

  2. Contrasting activity patterns of sympatric and allopatric black and grizzly bears

    Science.gov (United States)

    Schwartz, C.C.; Cain, S.L.; Podruzny, S.; Cherry, S.; Frattaroli, L.

    2010-01-01

    The distribution of grizzly (Ursus arctos) and American black bears (U. americanus) overlaps in western North America. Few studies have detailed activity patterns where the species are sympatric and no studies contrasted patterns where populations are both sympatric and allopatric. We contrasted activity patterns for sympatric black and grizzly bears and for black bears allopatric to grizzly bears, how human influences altered patterns, and rates of grizzlyblack bear predation. Activity patterns differed between black bear populations, with those sympatric to grizzly bears more day-active. Activity patterns of black bears allopatric with grizzly bears were similar to those of female grizzly bears; both were crepuscular and day-active. Male grizzly bears were crepuscular and night-active. Both species were more night-active and less day-active when ???1 km from roads or developments. In our sympatric study area, 2 of 4 black bear mortalities were due to grizzly bear predation. Our results suggested patterns of activity that allowed for intra- and inter-species avoidance. National park management often results in convergence of locally high human densities in quality bear habitat. Our data provide additional understanding into how bears alter their activity patterns in response to other bears and humans and should help park managers minimize undesirable bearhuman encounters when considering needs for temporal and spatial management of humans and human developments in bear habitats. ?? 2010 The Wildlife Society.

  3. Microsatellite analysis of paternity and reproduction in Arctic grizzly bears.

    Science.gov (United States)

    Craighead, L; Paetkau, D; Reynolds, H V; Vyse, E R; Strobeck, C

    1995-01-01

    We report data from analyses of microsatellite loci of 30 grizzly bear family groups which demonstrate that each cub in a litter can be sired independently, and we derive estimates of maximum reproductive success for males, from an Arctic population in northwestern Alaska that is minimally affected by human activities. These analyses were made possible by the use of single-locus primers that amplified both of an individual's alleles at eight microsatellite loci and by detailed knowledge of maternal/offspring relationships that allowed the identification of paternal alleles. No single male was responsible for more than approximately 11% of known offspring, and no more than 49% of breeding-age males successfully bred. These data contribute to an understanding of the genetic and demographic basis of male reproductive success, which is of vital importance in the maintenance of small, isolated grizzly bear populations.

  4. Oil and gas planning and development in Alberta : new approaches to integrate grizzly bear conservation

    Energy Technology Data Exchange (ETDEWEB)

    Stenhouse, G. [Foothills Model Forest Grizzly Bear Research Program, AB (Canada)

    2007-07-01

    This paper reported on a grizzly bear research program that was initiated in the province of Alberta to provide new knowledge and tools to ensure the long term survival of grizzly bears on a multiple use landscape. The Foothills Model Forest (FMF) Grizzly Bear Research Program was formed by scientists from across Canada from a variety of scientific disciplines. A strong partner base has been created to allow the FMF's research efforts to span the entire current distribution of grizzly bear habitat in Alberta. The FMF has provided new large scale seamless maps of grizzly bear habitat and, using detailed grizzly bear GPS movement data, has constructed and tested models that can identify key grizzly bear habitat. This presentation focused on the results of 9 years of applied research and described the new tools and models that are now available to program partners in Alberta. The products are currently being used by both industry and government in Alberta as new standards in landscape management planning in grizzly bear habitat. The author suggested that the approach taken with grizzly bears in Alberta could be used and adapted for a variety of wildlife species in the north. figs.

  5. New challenges for grizzly bear management in Yellowstone National Park

    Science.gov (United States)

    van Manen, Frank T.; Gunther, Kerry A.

    2016-01-01

    A key factor contributing to the success of grizzly bear Ursus arctos conservation in the Greater Yellowstone Ecosystem has been the existence of a large protected area, Yellowstone National Park. We provide an overview of recovery efforts, how demographic parameters changed as the population increased, and how the bear management program in Yellowstone National Park has evolved to address new management challenges over time. Finally, using the management experiences in Yellowstone National Park, we present comparisons and perspectives regarding brown bear management in Shiretoko National Park.

  6. Energy homeostasis regulatory peptides in hibernating grizzly bears.

    Science.gov (United States)

    Gardi, János; Nelson, O Lynne; Robbins, Charles T; Szentirmai, Eva; Kapás, Levente; Krueger, James M

    2011-05-15

    Grizzly bears (Ursus arctos horribilis) are inactive for up to 6 months during hibernation. They undergo profound seasonal changes in food intake, body mass, and energy expenditure. The circa-annual regulation of metabolism is poorly understood. In this study, we measured plasma ghrelin, leptin, obestatin, and neuropeptide-Y (NPY) levels, hormones known to be involved in the regulation of energy homeostasis, in ten grizzly bears. Blood samples were collected during the active summer period, early hibernation and late hibernation. Plasma levels of leptin, obestatin, and NPY did not change between the active and the hibernation periods. Plasma total ghrelin and desacyl-ghrelin concentrations significantly decreased during the inactive winter period compared to summer levels. The elevated ghrelin levels may help enhance body mass during pre-hibernation, while the low plasma ghrelin concentrations during hibernation season may contribute to the maintenance of hypophagia, low energy utilization and behavioral inactivity. Our results suggest that ghrelin plays a potential role in the regulation of metabolic changes and energy homeostasis during hibernation in grizzly bears.

  7. Salmon-Eating Grizzly Bears Exposed to Elevated Levels of Marine Derived Persistent Organic Pollutants

    Science.gov (United States)

    Christensen, J. R.; Ross, P. S.; Whiticar, M. J.

    2004-12-01

    The coastal grizzly bears of British Columbia (BC, Canada) rely heavily on salmon returning from the Pacific Ocean, whereas interior bears do not have access to or readily utilize this marine-derived food source. Since salmon have been shown to accumulate persistent organic pollutants (POPs) from the North Pacific Ocean, we hypothesized that salmon consumption by grizzly bears would be reflected by an increase in the POP burden. To test this hypothesis we collected hair and fat tissue from grizzlies at various locations around BC to compare salmon-eating (coastal) grizzlies to non-salmon-eating (interior) grizzlies. We characterized the feeding habits for each bear sampled by measuring the stable carbon and nitrogen isotope signature of their hair. The positive relationship between 13C/12C and 15N/14N isotopic ratios suggests that the majority of the meat portion of the diet of coastal grizzlies is coming from salmon, rather than from terrestrial or freshwater sources. By contrast, stable isotope ratios revealed that interior bears have an almost exclusive vegetarian diet with no marine influence. As hypothesized, the coastal grizzly bears have significantly greater OC pesticide and lower-brominated PBDE congener body burden than the interior grizzlies. We also found a positive relationship between C and N isotope ratios and these same POP contaminants in bear tissue. Overall, these results demonstrate that Pacific salmon represents a significant vector delivering both OC pesticides and PBDEs to BC coastal grizzly bears.

  8. Exploitation of pocket gophers and their food caches by grizzly bears

    Science.gov (United States)

    Mattson, D.J.

    2004-01-01

    I investigated the exploitation of pocket gophers (Thomomys talpoides) by grizzly bears (Ursus arctos horribilis) in the Yellowstone region of the United States with the use of data collected during a study of radiomarked bears in 1977-1992. My analysis focused on the importance of pocket gophers as a source of energy and nutrients, effects of weather and site features, and importance of pocket gophers to grizzly bears in the western contiguous United States prior to historical extirpations. Pocket gophers and their food caches were infrequent in grizzly bear feces, although foraging for pocket gophers accounted for about 20-25% of all grizzly bear feeding activity during April and May. Compared with roots individually excavated by bears, pocket gopher food caches were less digestible but more easily dug out. Exploitation of gopher food caches by grizzly bears was highly sensitive to site and weather conditions and peaked during and shortly after snowmelt. This peak coincided with maximum success by bears in finding pocket gopher food caches. Exploitation was most frequent and extensive on gently sloping nonforested sites with abundant spring beauty (Claytonia lanceolata) and yampah (Perdieridia gairdneri). Pocket gophers are rare in forests, and spring beauty and yampah roots are known to be important foods of both grizzly bears and burrowing rodents. Although grizzly bears commonly exploit pocket gophers only in the Yellowstone region, this behavior was probably widespread in mountainous areas of the western contiguous United States prior to extirpations of grizzly bears within the last 150 years.

  9. Genetic analysis reveals demographic fragmentation of grizzly bears yielding vulnerably small populations.

    Science.gov (United States)

    Proctor, Michael F; McLellan, Bruce N; Strobeck, Curtis; Barclay, Robert M R

    2005-11-22

    Ecosystem conservation requires the presence of native carnivores, yet in North America, the distributions of many larger carnivores have contracted. Large carnivores live at low densities and require large areas to thrive at the population level. Therefore, if human-dominated landscapes fragment remaining carnivore populations, small and demographically vulnerable populations may result. Grizzly bear range contraction in the conterminous USA has left four fragmented populations, three of which remain along the Canada-USA border. A tenet of grizzly bear conservation is that the viability of these populations requires demographic linkage (i.e. inter-population movement of both sexes) to Canadian bears. Using individual-based genetic analysis, our results suggest this demographic connection has been severed across their entire range in southern Canada by a highway and associated settlements, limiting female and reducing male movement. Two resulting populations are vulnerably small (bear populations may be more threatened than previously thought and that conservation efforts must expand to include international connectivity management. They also demonstrate the ability of genetic analysis to detect gender-specific demographic population fragmentation in recently disturbed systems, a traditionally intractable yet increasingly important ecological measurement worldwide.

  10. Serologic survey for Trichinella spp. in grizzly bears from Alaska.

    Science.gov (United States)

    Zarnke, R L; Gamble, R; Heckert, R A; Ver Hoef, J

    1997-07-01

    Blood was collected from 878 grizzly bears (Ursus arctos) in seven geographic areas of Alaska from 1973 to 1987. An enzyme-linked immunosorbent assay procedure was used to test sera for evidence of exposure to Trichinella spp. Serum antibody prevalence ranged from 5% (10 positive of 196 tested) in the Southern Region of the state to 83% (355 of 430 tested) in the Northern Region. These major discrepancies may be a result of differing food habits of bears in the major geographic areas. Prevalence was higher in older age cohorts. Neither year-of-collection nor sex had a significant effect on prevalence.

  11. Use of naturally occurring mercury to determine the importance of cutthroat trout to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Gunther, K.A.; Crock, J.G.; Haroldson, M.A.; Waits, L.; Robbins, C.T.

    2004-01-01

    Spawning cutthroat trout (Oncorhynchus clarki (Richardson, 1836)) are a potentially important food resource for grizzly bears (Ursus arctos horribilis Ord, 1815) in the Greater Yellowstone Ecosystem. We developed a method to estimate the amount of cutthroat trout ingested by grizzly bears living in the Yellowstone Lake area. The method utilized (i) the relatively high, naturally occurring concentration of mercury in Yellowstone Lake cutthroat trout (508 ± 93 ppb) and its virtual absence in all other bear foods (6 ppb), (ii) hair snares to remotely collect hair from bears visiting spawning cutthroat trout streams between 1997 and 2000, (iii) DNA analyses to identify the individual and sex of grizzly bears leaving a hair sample, (iv) feeding trials with captive bears to develop relationships between fish and mercury intake and hair mercury concentrations, and (v) mercury analyses of hair collected from wild bears to estimate the amount of trout consumed by each bear. Male grizzly bears consumed an average of 5 times more trout/kg bear than did female grizzly bears. Estimated cutthroat trout intake per year by the grizzly bear population was only a small fraction of that estimated by previous investigators, and males consumed 92% of all trout ingested by grizzly bears.

  12. Serologic survey of Toxoplasma gondii in grizzly bears (Ursus arctos) and black bears (Ursus americanus), from Alaska, 1988 to 1991.

    Science.gov (United States)

    Chomel, B B; Zarnke, R L; Kasten, R W; Kass, P H; Mendes, E

    1995-10-01

    We tested 644 serum samples from 480 grizzly bears and 40 black bears from Alaska (USA), collected between 1988 and 1991, for Toxoplasma gondii antibodies, using a commercially available latex agglutination test (LAT). A titer > or = 64 was considered positive. Serum antibody prevalence for T. gondii in grizzly bears (Ursus arctos) was 18% (87 of 480). Prevalence ranged from 9% (seven of 77) on Kodiak Island to 28% (15 of 54) in northern Alaska. Prevalence was directly correlated to age. No grizzly bears grizzly bears captured north of the Arctic Circle. Antibody prevalence in black bears (Ursus americanus) from Interior Alaska was 15% (six of 40), similar to the prevalence in grizzly bears from the same area (13%; five of 40).

  13. Methods to estimate distribution and range extent of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; , Daniel D. Bjornlie; , Daniel J. Thompson; , Kerry A. Gunther; , Steven L. Cain; , Daniel B. Tyers; Frey, Kevin L.; Aber, Bryan C.

    2014-01-01

    The distribution of the Greater Yellowstone Ecosystem grizzly bear (Ursus arctos) population has expanded into areas unoccupied since the early 20th century. Up-to-date information on the area and extent of this distribution is crucial for federal, state, and tribal wildlife and land managers to make informed decisions regarding grizzly bear management. The most recent estimate of grizzly bear distribution (2004) utilized fixed-kernel density estimators to describe distribution. This method was complex and computationally time consuming and excluded observations of unmarked bears. Our objective was to develop a technique to estimate grizzly bear distribution that would allow for the use of all verified grizzly bear location data, as well as provide the simplicity to be updated more frequently. We placed all verified grizzly bear locations from all sources from 1990 to 2004 and 1990 to 2010 onto a 3-km × 3-km grid and used zonal analysis and ordinary kriging to develop a predicted surface of grizzly bear distribution. We compared the area and extent of the 2004 kriging surface with the previous 2004 effort and evaluated changes in grizzly bear distribution from 2004 to 2010. The 2004 kriging surface was 2.4% smaller than the previous fixed-kernel estimate, but more closely represented the data. Grizzly bear distribution increased 38.3% from 2004 to 2010, with most expansion in the northern and southern regions of the range. This technique can be used to provide a current estimate of grizzly bear distribution for management and conservation applications.

  14. Fire, red squirrels, whitebark pine, and Yellowstone grizzly bears

    Science.gov (United States)

    Podruzny, Shannon; Reinhart, D.P.; Mattson, David J.

    1999-01-01

    Whitebark pine (Pinus albicaulis) habitats are important to Yellowstone grizzly bears (Ursus arctos) as refugia and sources of food. Ecological relationships between whitebark pine, red squirrels (Tamiasciurus hudsonicus), and grizzly bear use of pine seeds on Mt. Washburn in Yellowstone National Park, Wyoming, were examined during 1984-86. Following large-scale fires in 1988, we repeated the study in 1995-97 to examine the effects of fire on availability of whitebark pine seed in red squirrel middens and on bear use of middens. Half of the total length of the original line transects burned. We found no red squirrel middens in burned areas. Post-fire linear-abundance (no./km) of active squirrel middens that were pooled from burned and unburned areas decreased 27% compared to pre-fire abundance, but increased in unburned portions of some habitat types. Mean size of active middens decreased 54% post-fire. Use of pine seeds by bears (linear abundance of excavated middens) in pooled burned and unburned habitats decreased by 64%, likely due to the combined effects of reduced midden availability and smaller midden size. We discourage any further large-scale losses of seed producing trees from management-prescribed fires or timber harvesting until the effects of fire on ecological relationships in the whitebark pine zone are better understood.

  15. Physiologic responses of grizzly bears to different methods of capture.

    Science.gov (United States)

    Cattet, Marc R; Christison, Katina; Caulkett, Nigel A; Stenhouse, Gordon B

    2003-07-01

    The physiologic effects of two methods of capture, chemical immobilization of free-ranging (FR) bears by remote injection from a helicopter and physical restraint (PR) by leg-hold snare prior to chemical immobilization, were compared in 46 grizzly bears (Ursus arctos) handled during 90 captures between 1999 and 2001. Induction dosages and times were greater for FR bears than PR bears, a finding consistent with depletion of, or decreased sensitivity to, catecholamines. Free-ranging bears also had higher rectal temperatures 15 min following immobilization and temperatures throughout handling that correlated positively with induction time. Physically restrained bears had higher white blood cell counts, with more neutrophils and fewer lymphocytes and eosinophils, than did FR bears. This white blood cell profile was consistent with a stress leukogram, possibly affected by elevated levels of serum cortisol. Serum concentrations of alanine aminotransferase, aspartate aminotransferase, and creatine kinase were higher in PR bears that suggested muscle injury. Serum concentrations of sodium and chloride also were higher in PR bears and attributed to reduced body water volume through water deprivation and increased insensible water loss. Overall, different methods of capture resulted in different patterns of physiologic disturbance. Reducing pursuit and drug induction times should help to minimize increase in body temperature and alteration of acid-base balance in bears immobilized by remote injection. Minimizing restraint time and ensuring snare-anchoring cables are short should help to minimize loss of body water and prevent serious muscle injury in bears captured by leg-hold snare.

  16. Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods?

    Science.gov (United States)

    Barber-Meyer, Shannon M.

    2015-01-01

    This is a Forum article commenting on: Ripple, W. J., Beschta, R. L., Fortin, J. K., & Robbins, C. T. (2014) Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology, 83, 223–233. Comparisons Ripple et al. (2014) used to demonstrate increased fruit availability and consumption by grizzly bears post-wolf reintroduction are flawed and tenuous at best. Importantly, a more parsimonious (than trophic cascades) hypothesis, not sufficiently considered by Ripple et al., exists and is better supported by available data I review.

  17. Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods?

    Science.gov (United States)

    Barber-Meyer, Shannon M

    2015-05-01

    This is a Forum article commenting on: Ripple, W. J., Beschta, R. L., Fortin, J. K., & Robbins, C. T. (2014) Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology, 83, 223-233. Comparisons Ripple et al. (2014) used to demonstrate increased fruit availability and consumption by grizzly bears post-wolf reintroduction are flawed and tenuous at best. Importantly, a more parsimonious (than trophic cascades) hypothesis, not sufficiently considered by Ripple et al., exists and is better supported by available data I review.

  18. Serologic survey for Toxoplasma gondii in grizzly bears from Alaska.

    Science.gov (United States)

    Zarnke, R L; Dubey, J P; Kwok, O C; Ver Hoef, J M

    1997-04-01

    Blood samples were collected from 892 grizzly bears (Ursus arctos) in Alaska (USA) from 1973 to 1987. Sera were tested for evidence of exposure to Toxoplasma gondii by means of the modified agglutination test. Two hundred twenty sera (25%) had titers > or = 25, the minimum threshold titer. Six hundred seventy-two sera (75%) had titers < 25. Antibody prevalence ranged from 9% (18 positive of 196 tested) in southern areas to 37% (162 of 433 tested) in northern areas. There was no readily apparent explanation for these discrepancies in location-specific prevalence.

  19. Distribution of grizzly bears in the Greater Yellowstone Ecosystem, 2004

    Science.gov (United States)

    Schwartz, C.C.; Haroldson, M.A.; Gunther, K.; Moody, D.

    2006-01-01

    The US Fish and Wildlife Service (USFWS) proposed delisting the Yellowstone grizzly bear (Ursus arctos horribilis) in November 2005. Part of that process required knowledge of the most current distribution of the species. Here, we update an earlier estimate of occupied range (1990–2000) with data through 2004. We used kernel estimators to develop distribution maps of occupied habitats based on initial sightings of unduplicated females (n = 481) with cubs of the year, locations of radiomarked bears (n = 170), and spatially unique locations of conflicts, confrontations, and mortalities (n = 1,075). Although each data set was constrained by potential sampling bias, together they provided insight into areas in the Greater Yellowstone Ecosystem (GYE) currently occupied by grizzly bears. The current distribution of 37,258 km2 (1990–2004) extends beyond the distribution map generated with data from 1990–2000 (34,416 km2 ). Range expansion is particularly evident in parts of the Caribou–Targhee National Forest in Idaho and north of Spanish Peaks on the Gallatin National Forest in Montana.

  20. Body and diet composition of sympatric black and grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, Charles C.; Fortin, Jennifer K.; Teisberg, Justin E.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

    2013-01-01

    The Greater Yellowstone Ecosystem (GYE) has experienced changes in the distribution and availability of grizzly bear (Ursus arctos) food resources in recent decades. The decline of ungulates, fish, and whitebark pine seeds (Pinus albicaulis) has prompted questions regarding their ability to adapt. We examined body composition and diet of grizzly bears using bioelectrical impedance and stable isotopes to determine if 1) we can detect a change in diet quality associated with the decline in either ungulates or whitebark pine, and 2) the combined decline in ungulates, fish, and pine seeds resulted in a change in grizzly bear carrying capacity in the GYE. We contrasted body fat and mass in grizzly bears with a potential competitor, the American black bear (Ursus americanus), to address these questions. Grizzly bears assimilated more meat into their diet and were in better body condition than black bears throughout the study period, indicating the decline in ungulate resources did not affect grizzly bears more than black bears. We also found no difference in autumn fat levels in grizzly bears in years of good or poor pine seed production, and stable isotope analyses revealed this was primarily a function of switching to meat resources during poor seed-producing years. This dietary plasticity was consistent over the course of our study. We did not detect an overall downward trend in either body mass or the fraction of meat assimilated into the diet by grizzly bears over the past decade, but we did detect a downward trend in percent body fat in adult female grizzly bears after 2006. Whether this decline is an artifact of small sample size or due to the population reaching the ecological carrying capacity of the Yellowstone ecosystem warrants further investigation.

  1. Bacterial populations and metabolites in the feces of free roaming and captive grizzly bears.

    Science.gov (United States)

    Schwab, Clarissa; Cristescu, Bogdan; Boyce, Mark S; Stenhouse, Gordon B; Gänzle, Michael

    2009-12-01

    Gut physiology, host phylogeny, and diet determine the composition of the intestinal microbiota. Grizzly bears (Ursus arctos horribilis) belong to the Order Carnivora, yet feed on an omnivorous diet. The role of intestinal microflora in grizzly bear digestion has not been investigated. Microbiota and microbial activity were analysed from the feces of wild and captive grizzly bears. Bacterial composition was determined using culture-dependent and culture-independent methods. The feces of wild and captive grizzly bears contained log 9.1 +/- 0.5 and log 9.2 +/- 0.3 gene copies x g(-1), respectively. Facultative anaerobes Enterobacteriaceae and enterococci were dominant in wild bear feces. Among the strict anaerobes, the Bacteroides-Prevotella-Porphyromonas group was most prominent. Enterobacteriaceae were predominant in the feces of captive grizzly bears, at log 8.9 +/- 0.5 gene copies x g(-1). Strict anaerobes of the Bacteroides-Prevotella-Porphyromonas group and the Clostridium coccoides cluster were present at log 6.7 +/- 0.9 and log 6.8 +/- 0.8 gene copies x g(-1), respectively. The presence of lactate and short-chain fatty acids (SCFAs) verified microbial activity. Total SCFA content and composition was affected by diet. SCFA composition in the feces of captive grizzly bears resembled the SCFA composition of prey-consuming wild animals. A consistent data set was obtained that associated fecal microbiota and metabolites with the distinctive gut physiology and diet of grizzly bears.

  2. Demography and genetic structure of a recovering grizzly bear population

    Science.gov (United States)

    Kendall, K.C.; Stetz, J.B.; Boulanger, J.; Macleod, A.C.; Paetkau, David; White, Gary C.

    2009-01-01

    Grizzly bears (brown bears; Ursus arctos) are imperiled in the southern extent of their range worldwide. The threatened population in northwestern Montana, USA, has been managed for recovery since 1975; yet, no rigorous data were available to monitor program success. We used data from a large noninvasive genetic sampling effort conducted in 2004 and 33 years of physical captures to assess abundance, distribution, and genetic health of this population. We combined data from our 3 sampling methods (hair trap, bear rub, and physical capture) to construct individual bear encounter histories for use in Huggins-Pledger closed mark-recapture models. Our population estimate, N?? = 765 (95% CI = 715-831) was more than double the existing estimate derived from sightings of females with young. Based on our results, the estimated known, human-caused mortality rate in 2004 was 4.6% (95% CI = 4.2-4.9%), slightly above the 4% considered sustainable; however, the high proportion of female mortalities raises concern. We used location data from telemetry, confirmed sightings, and genetic sampling to estimate occupied habitat. We found that grizzly bears occupied 33,480 km2 in the Northern Continental Divide Ecosystem (NCDE) during 1994-2007, including 10,340 km beyond the Recovery Zone. We used factorial correspondence analysis to identify potential barriers to gene flow within this population. Our results suggested that genetic interchange recently increased in areas with low gene flow in the past; however, we also detected evidence of incipient fragmentation across the major transportation corridor in this ecosystem. Our results suggest that the NCDE population is faring better than previously thought, and they highlight the need for a more rigorous monitoring program.

  3. Disseminated pleomorphic myofibrosarcoma in a grizzly bear (Ursus arctos horribilis).

    Science.gov (United States)

    Mete, A; Woods, L; Famini, D; Anderson, M

    2012-01-01

    The pathological and diagnostic features of a widely disseminated pleomorphic high-grade myofibroblastic sarcoma are described in a 23-year-old male brown bear (Ursus arctos horribilis). Firm, solid, white to tan neoplastic nodules, often with cavitated or soft grey-red necrotic centres, were observed throughout most internal organs, subcutaneous tissues and skeletal muscles on gross examination. Microscopically, the tumour consisted of pleomorphic spindle cells forming interlacing fascicles with a focal storiform pattern with large numbers of bizarre polygonal multinucleate cells, frequently within a collagenous stroma. Immunohistochemistry, Masson's trichrome stain and transmission electron microscopy designated the myofibroblast as the cell of origin. This is the first case of a high-grade myofibrosarcoma in a grizzly bear.

  4. Grizzly bear hair reveals toxic exposure to mercury through salmon consumption.

    Science.gov (United States)

    Noël, Marie; Spence, Jody; Harris, Kate A; Robbins, Charles T; Fortin, Jennifer K; Ross, Peter S; Christensen, Jennie R

    2014-07-01

    Mercury obtained from the diet accumulates in mammalian hair as it grows thus preserving a record of mercury intake over the growth period of a given hair segment. We adapted a microanalysis approach, using laser ablation inductively coupled plasma mass spectrometry, to characterize temporal changes in mercury exposure and uptake in wild and captive grizzly bears. Captive grizzlies fed diets containing known and varied amounts of mercury provided data to allow prediction of Hg ingestion rates in wild bears. Here, we show, for the first time, that 70% of the coastal grizzly bears sampled had Hg levels exceeding the neurochemical effect level proposed for polar bears. In a context where the international community is taking global actions to reduce Hg emissions through the "Minamata Convention on Mercury", our study provides valuable information on the exposure to mercury of these grizzly bears already under many threats.

  5. Extirpations of grizzly bears in the contiguous United States of America, 1850-2000

    Science.gov (United States)

    Mattson, David J.; Merrill, Troy

    2002-01-01

    We investigated factors associated with the distribution of grizzly bears (Ursus arctos horribilis) in 1850 and their extirpation during 1850–1920 and 1920–1970 in the contiguous United States. We used autologistic regression to describe relations between grizzly bear range in 1850, 1920, and 1970 and potential explanatory factors specified for a comprehensive grid of cells, each 900 km2 in size. We also related persistence, 1920–1970, to range size and shape. Grizzly bear range in 1850 was positively related to occurrence in mountainous ecoregions and the ranges of oaks (Quercus spp.), piñon pines (Pinus edulis and P. monophylla), whitebark pine (P. albicaulis), and bison (Bos bison) and negatively related to occurrence in prairie and hot desert ecoregions. Relations with salmon (Oncorynchus spp.) range and human factors were complex. Persistence of grizzly bear range, 1850–1970, was positively related to occurrence in the Rocky Mountains, whitebark pine range, and local size of grizzly bear range at the beginning of each period, and negatively related to number of humans and the ranges of bison, salmon, and piñon pines. We speculate that foods affected persistence primarily by influencing the frequency of contact between humans and bears. With respect to current conservation, grizzly bears survived from 1920 to 1970 most often where ranges at the beginning of this period were either larger than 20,000 km2 or larger than 7,000 km2 but with a ratio of perimeter to area of grizzly bear range would be as extensive as it is now. Although grizzly bear range in the Yellowstone region is currently the most robust of any to potential future increases in human lethality, bears in this region are threatened by the loss of whitebark pine.

  6. Grizzly Bear Aware: Conflict Resolution and Habitat Restoration in the Centennial Valley and Southwest Montana

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project will take a three pronged approach to implement conservation actions that prevent or reduce Grizzly Bear human conflicts, enhance habitats and improve...

  7. Prevalence of Trichinella spp. in black bears, grizzly bears, and wolves in the Dehcho Region, Northwest Territories, Canada, including the first report of T. nativa in a grizzly bear from Canada.

    Science.gov (United States)

    Larter, Nicholas C; Forbes, Lorry B; Elkin, Brett T; Allaire, Danny G

    2011-07-01

    Samples of muscle from 120 black bears (Ursus americanus), 11 grizzly bears (Ursus arctos), and 27 wolves (Canis lupus) collected in the Dehcho Region of the Northwest Territories from 2001 to 2010 were examined for the presence of Trichinella spp. larvae using a pepsin-HCl digestion assay. Trichinella spp. larvae were found in eight of 11 (73%) grizzly bears, 14 of 27 (52%) wolves, and seven of 120 (5.8%) black bears. The average age of positive grizzly bears, black bears, and wolves was 13.5, 9.9, and approximately 4 yr, respectively. Larvae from 11 wolves, six black bears, and seven grizzly bears were genotyped. Six wolves were infected with T. nativa and five with Trichinella T6, four black bears were infected with T. nativa and two with Trichinella T6, and all seven grizzly bears were infected with Trichinella T6 and one of them had a coinfection with T. nativa. This is the first report of T. nativa in a grizzly bear from Canada. Bears have been linked to trichinellosis outbreaks in humans in Canada, and black bears are a subsistence food source for residents of the Dehcho region. In order to assess food safety risk it is important to monitor the prevalence of Trichinella spp. in both species of bear and their cohabiting mammalian food sources.

  8. Grizzly bear-human conflicts in the Yellowstone Ecosystem, 1992-2000

    Science.gov (United States)

    Gunther, K.A.; Haroldson, M.A.; Cain, S.L.; Copeland, J.; Frey, K.; Schwartz, C.C.

    2004-01-01

    For many years, the primary strategy for managing grizzly bears (Ursus arctos) that came into conflict with humans in the Greater Yellowstone Ecosystem (GYE) was to capture and translocate the offending bears away from conflict sites. Translocation usually only temporarily alleviated the problems and most often did not result in long-term solutions. Wildlife managers needed to be able to predict the causes, types, locations, and trends of conflicts to more efficiently allocate resources for pro-active rather than reactive management actions. To address this need, we recorded all grizzly bear-human conflicts reported in the GYE during 1992-2000. We analyzed trends in conflicts over time (increasing or decreasing), geographic location on macro- (inside or outside of the designated Yellowstone Grizzly Bear Recovery Zone [YGBRZ]) and micro- (geographic location) scales, land ownership (public or private), and relationship to the seasonal availability of bear foods. We recorded 995 grizzly bear-human conflicts in the GYE. Fifty-three percent of the conflicts occurred outside and 47% inside the YGBRZ boundary. Fifty-nine percent of the conflicts occurred on public and 41% on private land. Incidents of bears damaging property and obtaining anthropogenic foods were inversely correlated to the abundance of naturally occurring bear foods. Livestock depredations occurred independent of the availability of bear foods. To further aid in prioritizing management strategies to reduce conflicts, we also analyzed conflicts in relation to subsequent human-caused grizzly bear mortality. There were 74 human-caused grizzly bear mortalities during the study, primarily from killing bears in defense of life and property (43%) and management removal of bears involved in bear-human conflicts (28%). Other sources of human-caused mortality included illegal kills, electrocution by downed power-lines, mistaken identification by American black bear (Ursus americanus) hunters, and vehicle strikes

  9. Contrafreeloading in grizzly bears: implications for captive foraging enrichment.

    Science.gov (United States)

    McGowan, Ragen T S; Robbins, Charles T; Alldredge, J Richard; Newberry, Ruth C

    2010-01-01

    Although traditional feeding regimens for captive animals were focused on meeting physiological needs to assure good health, more recently emphasis has also been placed on non-nutritive aspects of feeding. The provision of foraging materials to diversify feeding behavior is a common practice in zoos but selective consumption of foraging enrichment items over more balanced "chow" diets could lead to nutrient imbalance. One alternative is to provide balanced diets in a contrafreeloading paradigm. Contrafreeloading occurs when animals choose resources that require effort to exploit when identical resources are freely available. To investigate contrafreeloading and its potential as a theoretical foundation for foraging enrichment, we conducted two experiments with captive grizzly bears (Ursus arctos horribilis). In Experiment 1, bears were presented with five foraging choices simultaneously: apples, apples in ice, salmon, salmon in ice, and plain ice under two levels of food restriction. Two measures of contrafreeloading were considered: weight of earned food consumed and time spent working for earned food. More free than earned food was eaten, with only two bears consuming food extracted from ice, but all bears spent more time manipulating ice containing salmon or apples than plain ice regardless of level of food restriction. In Experiment 2, food-restricted bears were presented with three foraging choices simultaneously: apples, apples inside a box, and an empty box. Although they ate more free than earned food, five bears consumed food from boxes and all spent more time manipulating boxes containing apples than empty boxes. Our findings support the provision of contrafreeloading opportunities as a foraging enrichment strategy for captive wildlife.

  10. The natural food habits of grizzly bears in Yellowstone National Park, 1973-74

    Science.gov (United States)

    Mealey, Stephen Patrick

    1980-01-01

     The natural food habits of grizzly bears (Ursus arctos horribilis Ord) in Yellowstone National Park were investigated in 1973-74 to identify the grizzly's energy sources and trophic level(s), nutrient use, and distribution. Food consumption was determined by scat analysis and field observations. Food quality and digestibility were estimated by chemical analysis. Grizzlies were distributed in 3 distinctive feeding economies: valley/plateau, a grass/rodent economy where grizzlies were intensive diggers; mountain, primarily a grass/springbeauty/root economy where grizzlies were casual diggers; and lake, primarily a fish/grass economy where grizzlies were fishers. The economies occured in areas with fertile soils; distribution of bears within each was related to the occurrence of succulent plants. The feeding cycle in the valley/plateau and mountain economies followed plant phenology. Grizzlies fed primarily on meat before green-up and on succulent herbs afterwards; meat, corms, berries, and nuts became important during the postgrowing season. Succulent grasses and sedges with an importance value percentage of 78.5 were the most important food items consumed. Protein from animal tissue was more digestible than protein from plant tissue. Storage fats were more digestible than structural fats. Food energy and digestibility were directly related. Five principle nutrient materials (listed with their percentage digestibilities) contributed to total energy intake: protein from succulent herbs, 42.8; protein and fat from animal material, 78.1; fat and protein from pine nuts, 73.6; starch, 78.8; and sugar from berries and fruits, digestibility undetermined. Protein from succulent herbs, with a nutritive value percentage of 77.3, was the grizzlies' primary energy source. Because succulent, preflowering herbs had higher protein levels than dry, mature herbs, grizzly use of succulent herbs guaranteed them the highest source of herbaceous protein. Low protein digestibility of

  11. Seasonal habitat use and selection by grizzly bears in Northern British Columbia

    Science.gov (United States)

    Milakovic, B.; Parker, K.L.; Gustine, D.D.; Lay, R.J.; Walker, A.B.D.; Gillingham, M.P.

    2012-01-01

    We defined patterns of habitat use and selection by female grizzly bears (Ursus arctos) in the Besa-Prophet watershed of northern British Columbia. We fitted 13 adult females with Geographic Positioning System (GPS) radio-collars and monitored them between 2001 and 2004. We examined patterns of habitat selection by grizzly bears relative to topographical attributes and 3 potential surrogates of food availability: land-cover class, vegetation biomass or quality (as measured by the Normalized Difference Vegetation Index), and selection value for prey species themselves (moose [Alces alces], elk [Cervus elaphus], woodland caribou [Rangifer tarandus], Stone's sheep [Ovis dalli stonei]). Although vegetation biomass and quality, and selection values for prey were important in seasonal selection by some individual bears, land-cover class, elevation, aspect, and vegetation diversity most influenced patterns of habitat selection across grizzly bears, which rely on availability of plant foods and encounters with ungulate prey. Grizzly bears as a group avoided conifer stands and areas of low vegetation diversity, and selected for burned land-cover classes and high vegetation diversity across seasons. They also selected mid elevations from what was available within seasonal ranges. Quantifying relative use of different attributes helped place selection patterns within the context of the landscape. Grizzly bears used higher elevations (1,595??31 m SE) in spring and lower elevations (1,436??27 m) in fall; the range of average elevations used among individuals was highest (500 m) during the summer. During all seasons, grizzly bears most frequented aspects with high solar gain. Use was distributed across 10 land-cover classes and depended on season. Management and conservation actions must maintain a diverse habitat matrix distributed across a large elevational gradient to ensure persistence of grizzly bears as levels of human access increase in the northern Rocky Mountains

  12. Spatial patterns of breeding success of grizzly bears derived from hierarchical multistate models.

    Science.gov (United States)

    Fisher, Jason T; Wheatley, Matthew; Mackenzie, Darryl

    2014-10-01

    Conservation programs often manage populations indirectly through the landscapes in which they live. Empirically, linking reproductive success with landscape structure and anthropogenic change is a first step in understanding and managing the spatial mechanisms that affect reproduction, but this link is not sufficiently informed by data. Hierarchical multistate occupancy models can forge these links by estimating spatial patterns of reproductive success across landscapes. To illustrate, we surveyed the occurrence of grizzly bears (Ursus arctos) in the Canadian Rocky Mountains Alberta, Canada. We deployed camera traps for 6 weeks at 54 surveys sites in different types of land cover. We used hierarchical multistate occupancy models to estimate probability of detection, grizzly bear occupancy, and probability of reproductive success at each site. Grizzly bear occupancy varied among cover types and was greater in herbaceous alpine ecotones than in low-elevation wetlands or mid-elevation conifer forests. The conditional probability of reproductive success given grizzly bear occupancy was 30% (SE = 0.14). Grizzly bears with cubs had a higher probability of detection than grizzly bears without cubs, but sites were correctly classified as being occupied by breeding females 49% of the time based on raw data and thus would have been underestimated by half. Repeated surveys and multistate modeling reduced the probability of misclassifying sites occupied by breeders as unoccupied to grizzly bear occupancy varied across the landscape. Those patches with highest probabilities of breeding occupancy-herbaceous alpine ecotones-were small and highly dispersed and are projected to shrink as treelines advance due to climate warming. Understanding spatial correlates in breeding distribution is a key requirement for species conservation in the face of climate change and can help identify priorities for landscape management and protection.

  13. Exertional myopathy in a grizzly bear (Ursus arctos) captured by leghold snare.

    Science.gov (United States)

    Cattet, Marc; Stenhouse, Gordon; Bollinger, Trent

    2008-10-01

    We diagnosed exertional myopathy (EM) in a grizzly bear (Ursus arctos) that died approximately 10 days after capture by leghold snare in west-central Alberta, Canada, in June 2003. The diagnosis was based on history, post-capture movement data, gross necropsy, histopathology, and serum enzyme levels. We were unable to determine whether EM was the primary cause of death because autolysis precluded accurate evaluation of all tissues. Nevertheless, comparison of serum aspartate aminotransferase and creatine kinase concentrations and survival between the affected bear and other grizzly bears captured by leghold snare in the same research project suggests EM also occurred in other bears, but that it is not generally a cause of mortality. We propose, however, occurrence of nonfatal EM in grizzly bears after capture by leghold snare has potential implications for use of this capture method, including negative effects on wildlife welfare and research data.

  14. Cardiac function adaptations in hibernating grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Nelson, O Lynne; Robbins, Charles T

    2010-03-01

    Research on the cardiovascular physiology of hibernating mammals may provide insight into evolutionary adaptations; however, anesthesia used to handle wild animals may affect the cardiovascular parameters of interest. To overcome these potential biases, we investigated the functional cardiac phenotype of the hibernating grizzly bear (Ursus arctos horribilis) during the active, transitional and hibernating phases over a 4 year period in conscious rather than anesthetized bears. The bears were captive born and serially studied from the age of 5 months to 4 years. Heart rate was significantly different from active (82.6 +/- 7.7 beats/min) to hibernating states (17.8 +/- 2.8 beats/min). There was no difference from the active to the hibernating state in diastolic and stroke volume parameters or in left atrial area. Left ventricular volume:mass was significantly increased during hibernation indicating decreased ventricular mass. Ejection fraction of the left ventricle was not different between active and hibernating states. In contrast, total left atrial emptying fraction was significantly reduced during hibernation (17.8 +/- 2.8%) as compared to the active state (40.8 +/- 1.9%). Reduced atrial chamber function was also supported by reduced atrial contraction blood flow velocities and atrial contraction ejection fraction during hibernation; 7.1 +/- 2.8% as compared to 20.7 +/- 3% during the active state. Changes in the diastolic cardiac filling cycle, especially atrial chamber contribution to ventricular filling, appear to be the most prominent macroscopic functional change during hibernation. Thus, we propose that these changes in atrial chamber function constitute a major adaptation during hibernation which allows the myocardium to conserve energy, avoid chamber dilation and remain healthy during a period of extremely low heart rates. These findings will aid in rational approaches to identifying underlying molecular mechanisms.

  15. Confronting uncertainty in wildlife management: performance of grizzly bear management.

    Directory of Open Access Journals (Sweden)

    Kyle A Artelle

    Full Text Available Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone--discrepancy between expected and realized mortality levels--led to excess mortality in 19% of cases (population-years examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.

  16. Confronting uncertainty in wildlife management: performance of grizzly bear management.

    Science.gov (United States)

    Artelle, Kyle A; Anderson, Sean C; Cooper, Andrew B; Paquet, Paul C; Reynolds, John D; Darimont, Chris T

    2013-01-01

    Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone--discrepancy between expected and realized mortality levels--led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty.

  17. Wolves trigger a trophic cascade to berries as alternative food for grizzly bears.

    Science.gov (United States)

    Ripple, William J; Beschta, Robert L; Fortin, Jennifer K; Robbins, Charles T

    2015-05-01

    This is a Forum article in response to: Barber-Meyer, S. (2015) Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods? Journal of Animal Ecology, 83, doi: 10.1111/1365-2656.12338. We used multiple data sets and study areas as well as several lines of evidence to investigate potential trophic linkages in Yellowstone National Park. Our results suggest that a trophic cascade from wolves to elk to berry production to berry consumption by grizzly bears may now be underway in the Park.

  18. Temporal, spatial, and environmental influences on the demographics of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, Charles C.; Haroldson, Mark A.; White, Gary C.; Harris, Richard B.; Cherry, Steve; Keating, Kim A.; Moody, Dave; Servheen, Christopher

    2006-01-01

    During the past 2 decades, the grizzly bear (Ursus arctos) population in the Greater Yellowstone Ecosystem (GYE) has increased in numbers and expanded in range. Understanding temporal, environmental, and spatial variables responsible for this change is useful in evaluating what likely influenced grizzly bear demographics in the GYE and where future management efforts might benefit conservation and management. We used recent data from radio-marked bears to estimate reproduction (1983–2002) and survival (1983–2001); these we combined into models to evaluate demographic vigor (lambda [λ]). We explored the influence of an array of individual, temporal, and spatial covariates on demographic vigor.

  19. USE OF SULFUR AND NITROGEN STABLE ISOTOPES TO DETERMINE THE IMPORTANCE OF WHITEBARK PINE NUTS TO YELLOWSTONE GRIZZLY BEARS

    Science.gov (United States)

    Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat and protein-rich nuts that are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years and poor crops in other years. Grizzly bear survival in ...

  20. Nature vs. Nurture: Evidence for Social Learning of Conflict Behaviour in Grizzly Bears.

    Science.gov (United States)

    Morehouse, Andrea T; Graves, Tabitha A; Mikle, Nate; Boyce, Mark S

    2016-01-01

    The propensity for a grizzly bear to develop conflict behaviours might be a result of social learning between mothers and cubs, genetic inheritance, or both learning and inheritance. Using non-invasive genetic sampling, we collected grizzly bear hair samples during 2011-2014 across southwestern Alberta, Canada. We targeted private agricultural lands for hair samples at grizzly bear incident sites, defining an incident as an occurrence in which the grizzly bear caused property damage, obtained anthropogenic food, or killed or attempted to kill livestock or pets. We genotyped 213 unique grizzly bears (118 M, 95 F) at 24 microsatellite loci, plus the amelogenin marker for sex. We used the program COLONY to assign parentage. We evaluated 76 mother-offspring relationships and 119 father-offspring relationships. We compared the frequency of problem and non-problem offspring from problem and non-problem parents, excluding dependent offspring from our analysis. Our results support the social learning hypothesis, but not the genetic inheritance hypothesis. Offspring of problem mothers are more likely to be involved in conflict behaviours, while offspring from non-problem mothers are not likely to be involved in incidents or human-bear conflicts themselves (Barnard's test, p = 0.05, 62.5% of offspring from problem mothers were problem bears). There was no evidence that offspring are more likely to be involved in conflict behaviour if their fathers had been problem bears (Barnard's test, p = 0.92, 29.6% of offspring from problem fathers were problem bears). For the mother-offspring relationships evaluated, 30.3% of offspring were identified as problem bears independent of their mother's conflict status. Similarly, 28.6% of offspring were identified as problem bears independent of their father's conflict status. Proactive mitigation to prevent female bears from becoming problem individuals likely will help prevent the perpetuation of conflicts through social learning.

  1. Nature vs. nurture: Evidence for social learning of conflict behaviour in grizzly bears

    Science.gov (United States)

    Morehouse, Andrea T.; Graves, Tabitha A.; Mikle, Nathaniel; Boyce, Mark S.

    2016-01-01

    The propensity for a grizzly bear to develop conflict behaviours might be a result of social learning between mothers and cubs, genetic inheritance, or both learning and inheritance. Using non-invasive genetic sampling, we collected grizzly bear hair samples during 2011–2014 across southwestern Alberta, Canada. We targeted private agricultural lands for hair samples at grizzly bear incident sites, defining an incident as an occurrence in which the grizzly bear caused property damage, obtained anthropogenic food, or killed or attempted to kill livestock or pets. We genotyped 213 unique grizzly bears (118 M, 95 F) at 24 microsatellite loci, plus the amelogenin marker for sex. We used the program COLONY to assign parentage. We evaluated 76 mother-offspring relationships and 119 father-offspring relationships. We compared the frequency of problem and non-problem offspring from problem and non-problem parents, excluding dependent offspring from our analysis. Our results support the social learning hypothesis, but not the genetic inheritance hypothesis. Offspring of problem mothers are more likely to be involved in conflict behaviours, while offspring from non-problem mothers are not likely to be involved in incidents or human-bear conflicts themselves (Barnard’s test, p = 0.05, 62.5% of offspring from problem mothers were problem bears). There was no evidence that offspring are more likely to be involved in conflict behaviour if their fathers had been problem bears (Barnard’s test, p = 0.92, 29.6% of offspring from problem fathers were problem bears). For the mother-offspring relationships evaluated, 30.3% of offspring were identified as problem bears independent of their mother’s conflict status. Similarly, 28.6% of offspring were identified as problem bears independent of their father’s conflict status. Proactive mitigation to prevent female bears from becoming problem individuals likely will help prevent the perpetuation of conflicts through social learning.

  2. The impact of roads on the demography of grizzly bears in Alberta.

    Science.gov (United States)

    Boulanger, John; Stenhouse, Gordon B

    2014-01-01

    One of the principal factors that have reduced grizzly bear populations has been the creation of human access into grizzly bear habitat by roads built for resource extraction. Past studies have documented mortality and distributional changes of bears relative to roads but none have attempted to estimate the direct demographic impact of roads in terms of both survival rates, reproductive rates, and the interaction of reproductive state of female bears with survival rate. We applied a combination of survival and reproductive models to estimate demographic parameters for threatened grizzly bear populations in Alberta. Instead of attempting to estimate mean trend we explored factors which caused biological and spatial variation in population trend. We found that sex and age class survival was related to road density with subadult bears being most vulnerable to road-based mortality. A multi-state reproduction model found that females accompanied by cubs of the year and/or yearling cubs had lower survival rates compared to females with two year olds or no cubs. A demographic model found strong spatial gradients in population trend based upon road density. Threshold road densities needed to ensure population stability were estimated to further refine targets for population recovery of grizzly bears in Alberta. Models that considered lowered survival of females with dependant offspring resulted in lower road density thresholds to ensure stable bear populations. Our results demonstrate likely spatial variation in population trend and provide an example how demographic analysis can be used to refine and direct conservation measures for threatened species.

  3. Trichinellosis acquired in Nunavut, Canada in September 2009: meat from grizzly bear suspected.

    Science.gov (United States)

    Houzé, S; Ancelle, T; Matra, R; Boceno, C; Carlier, Y; Gajadhar, A A; Dupouy-Camet, J

    2009-11-05

    Five cases of trichinellosis with onset of symptoms in September 2009, were reported in France, and were probably linked to the consumption of meat from a grizzly bear in Cambridge Bay in Nunavut, Canada. Travellers should be aware of the risks of eating raw or rare meat products in arctic regions, particularly game meat such as bear or walrus meat.

  4. Moose, caribou, and grizzly bear distribution in relation to road traffic in Denali National Park, Alaska

    Science.gov (United States)

    Yost, A.C.; Wright, R.G.

    2001-01-01

    Park managers are concerned that moose (Alces alces), caribou (Rangifer tarandus), and grizzly bears (Ursus arctos) may be avoiding areas along the 130 km road through Denali National Park as a result of high traffic volume, thus decreasing opportunities for visitors to view wildlife. A wildlife monitoring system was developed in 1996 that used 19 landscape level viewsheds, stratified into four sections based on decreasing traffic along the road corridor. Data were collected from 22 samplings of all viewsheds during May-August in 1996 and 1997. In 1997, nine backcountry viewsheds were established in three different areas to determine whether density estimates for each species in the backcountry were higher than those for the same animals in similar road-corridor areas. Densities higher than those in the road corridor were found in one backcountry area for moose and in two backcountry areas for grizzly bears. None of the backcountry areas showed a higher density of caribou. We tested hypotheses that moose, caribou, and grizzly bear distributions were unrelated to the road and traffic. Moose sightings were lower than expected within 300 m of the road. More caribou and grizzly bears than expected occurred between 601 and 900 m from the road, while more moose and fewer caribou than expected occurred between 900 and 1200 m from the road. Bull moose in stratum 1 were distributed farther from the road than bulls and cows in stratum 4; cows in stratum 1 and bulls in stratum 2 were distributed farther from the road than cows in stratum 4. Grizzly bears in stratum 2 were distributed farther from the road than bears in stratum 3. The distribution of moose sightings suggests traffic avoidance, but the spatial pattern of preferred forage may have had more of an influence. Caribou and grizzly bear distributions indicated no pattern of traffic avoidance.

  5. Titin isoform switching is a major cardiac adaptive response in hibernating grizzly bears.

    Science.gov (United States)

    Nelson, O Lynne; Robbins, Charles T; Wu, Yiming; Granzier, Henk

    2008-07-01

    The hibernation phenomenon captures biological as well as clinical interests to understand how organs adapt. Here we studied how hibernating grizzly bears (Ursus arctos horribilis) tolerate extremely low heart rates without developing cardiac chamber dilation. We evaluated cardiac filling function in unanesthetized grizzly bears by echocardiography during the active and hibernating period. Because both collagen and titin are involved in altering diastolic function, we investigated both in the myocardium of active and hibernating grizzly bears. Heart rates were reduced from 84 beats/min in active bears to 19 beats/min in hibernating bears. Diastolic volume, stroke volume, and left ventricular ejection fraction were not different. However, left ventricular muscle mass was significantly lower (300 +/- 12 compared with 402 +/- 14 g; P = 0.003) in the hibernating bears, and as a result the diastolic volume-to-left ventricular muscle mass ratio was significantly greater. Early ventricular filling deceleration times (106.4 +/- 14 compared with 143.2 +/- 20 ms; P = 0.002) were shorter during hibernation, suggesting increased ventricular stiffness. Restrictive pulmonary venous flow patterns supported this conclusion. Collagen type I and III comparisons did not reveal differences between the two groups of bears. In contrast, the expression of titin was altered by a significant upregulation of the stiffer N2B isoform at the expense of the more compliant N2BA isoform. The mean ratio of N2BA to N2B titin was 0.73 +/- 0.07 in the active bears and decreased to 0.42 +/- 0.03 (P = 0.006) in the hibernating bears. The upregulation of stiff N2B cardiac titin is a likely explanation for the increased ventricular stiffness that was revealed by echocardiography, and we propose that it plays a role in preventing chamber dilation in hibernating grizzly bears. Thus our work identified changes in the alternative splicing of cardiac titin as a major adaptive response in hibernating grizzly

  6. Persistent organic pollutants in British Columbia grizzly bears: consequence of divergent diets.

    Science.gov (United States)

    Christensen, Jennie R; MacDuffee, Misty; Macdonald, Robie W; Whiticar, Michael; Ross, Peter S

    2005-09-15

    Nitrogen and carbon stable isotope signatures in growing hair reveal that while some British Columbia grizzly bears (Ursus arctos horribilis) rely entirely on terrestrial foods, others switch in late summer to returning Pacific salmon (Oncorynchus spp.). Implications for persistent organic pollutant (POP) concentrations and patterns measured in the two feeding groups of grizzly bears were profound. While the bears consuming a higher proportion of terrestrial vegetation ("interior" grizzlies) exhibited POP patterns dominated bythe more volatile organochlorine (OC) pesticides and the heavier polybrominated diphenyl ethers (PBDEs: e.g., BDE-209), the bears consuming salmon were dominated by the more bioaccumulative POPs (e.g., DDT, chlordanes, and BDE-47). The ocean-salmon-bear pathway appeared to preferentially select for those contaminants with intermediate partitioning strength from water into lipid (log Kow approximately 6.5). This pattern reflects an optimum contaminant log Kow range for atmospheric transport, deposition into the marine environment, uptake into marine biota, accumulation through the food web, and retention in the bear tissues. We estimate that salmon deliver 70% of all OC pesticides, up to 85% of the lower brominated PBDE congeners, and 90% of PCBs found in salmon-eating grizzly bears, thereby inextricably linking these terrestrial predators to contaminants from the North Pacific Ocean.

  7. Population growth of Yellowstone grizzly bears: Uncertainty and future monitoring

    Science.gov (United States)

    Harris, R.B.; White, Gary C.; Schwartz, C.C.; Haroldson, M.A.

    2007-01-01

    Grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem of the US Rocky Mountains have recently increased in numbers, but remain vulnerable due to isolation from other populations and predicted reductions in favored food resources. Harris et al. (2006) projected how this population might fare in the future under alternative survival rates, and in doing so estimated the rate of population growth, 1983–2002. We address issues that remain from that earlier work: (1) the degree of uncertainty surrounding our estimates of the rate of population change (λ); (2) the effect of correlation among demographic parameters on these estimates; and (3) how a future monitoring system using counts of females accompanied by cubs might usefully differentiate between short-term, expected, and inconsequential fluctuations versus a true change in system state. We used Monte Carlo re-sampling of beta distributions derived from the demographic parameters used by Harris et al. (2006) to derive distributions of λ during 1983–2002 given our sampling uncertainty. Approximate 95% confidence intervals were 0.972–1.096 (assuming females with unresolved fates died) and 1.008–1.115 (with unresolved females censored at last contact). We used well-supported models of Haroldson et al. (2006) and Schwartz et al. (2006a,b,c) to assess the strength of correlations among demographic processes and the effect of omitting them in projection models. Incorporating correlations among demographic parameters yielded point estimates of λ that were nearly identical to those from the earlier model that omitted correlations, but yielded wider confidence intervals surrounding λ. Finally, we suggest that fitting linear and quadratic curves to the trend suggested by the estimated number of females with cubs in the ecosystem, and using AICc model weights to infer population sizes and λ provides an objective means to monitoring approximate population trajectories in addition to demographic

  8. Persistent or not persistent? Polychlorinated biphenyls are readily depurated by grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Christensen, Jennie R; Letcher, Robert J; Ross, Peter S

    2009-10-01

    Major pharmacokinetic processes influencing polychlorinated biphenyl (PCB) accumulation in mammals include uptake, biotransformation, respiration, and excretion. We characterized some of the factors underlying PCB accumulation/loss by evaluating PCB concentrations and patterns in pre- and posthibernation grizzly bears (Ursus arctos horribilis) and their prey. The PCB congeners with vicinal meta- and para-chlorine unsubstituted hydrogen positions consistently showed loss both before and during hibernation, supporting the idea of a dominant role for biotransformation. Retention of all other studied congeners relative to that of PCB 194 varied widely (from bears do not eat or excrete. We estimate that grizzly bears retain less than 10% of total PCBs taken up from their diet. Our results suggest that for grizzly bears, depuration of PCBs via biotransformation is important (explaining approximately 40% of loss), but that nonbiotransformation processes, such as excretion, may be more important (explaining approximately 60% of loss). These findings, together with the approximately 91% loss of the persistent PCB 153 congener relative to PCB 194 in grizzly bears, raise important questions about how one defines persistence of PCBs in wildlife and may have bearing on the interpretation of food-web biomagnification studies.

  9. Grizzly Bear Noninvasive Genetic Tagging Surveys: Estimating the Magnitude of Missed Detections.

    Science.gov (United States)

    Fisher, Jason T; Heim, Nicole; Code, Sandra; Paczkowski, John

    2016-01-01

    Sound wildlife conservation decisions require sound information, and scientists increasingly rely on remotely collected data over large spatial scales, such as noninvasive genetic tagging (NGT). Grizzly bears (Ursus arctos), for example, are difficult to study at population scales except with noninvasive data, and NGT via hair trapping informs management over much of grizzly bears' range. Considerable statistical effort has gone into estimating sources of heterogeneity, but detection error-arising when a visiting bear fails to leave a hair sample-has not been independently estimated. We used camera traps to survey grizzly bear occurrence at fixed hair traps and multi-method hierarchical occupancy models to estimate the probability that a visiting bear actually leaves a hair sample with viable DNA. We surveyed grizzly bears via hair trapping and camera trapping for 8 monthly surveys at 50 (2012) and 76 (2013) sites in the Rocky Mountains of Alberta, Canada. We used multi-method occupancy models to estimate site occupancy, probability of detection, and conditional occupancy at a hair trap. We tested the prediction that detection error in NGT studies could be induced by temporal variability within season, leading to underestimation of occupancy. NGT via hair trapping consistently underestimated grizzly bear occupancy at a site when compared to camera trapping. At best occupancy was underestimated by 50%; at worst, by 95%. Probability of false absence was reduced through successive surveys, but this mainly accounts for error imparted by movement among repeated surveys, not necessarily missed detections by extant bears. The implications of missed detections and biased occupancy estimates for density estimation-which form the crux of management plans-require consideration. We suggest hair-trap NGT studies should estimate and correct detection error using independent survey methods such as cameras, to ensure the reliability of the data upon which species management and

  10. Predatory behavior of grizzly bears feeding on elk calves in Yellowstone National Park

    Science.gov (United States)

    French, Steven P.; French, Marilynn G.

    1990-01-01

    Grizzly bears (Ursus arctos horribilis) were observed preying on elk calves (Cervus elaphus) on 60 occasions in Yellowstone National Park, with 29 confirmed kills. Some bears were deliberate predators and effectively preyed on elk calves for short periods each spring, killing up to 1 calf daily. Primary hunting techniques were searching and chasing although some bears used a variety of techniques during a single hunt. They hunted both day and night and preyed on calves in the open and in the woods. Excess killing occurred when circumstances permitted. One bear caught 5 calves in a 15-minute interval. Elk used a variety of antipredator defenses and occasionally attacked predacious bears. The current level of this feeding behavior appears to be greater than previously reported. This is probably related to the increased availability of calves providing a greater opportunity for learning, and the adaptation of a more predatory behavior by some grizzly bears in Yellowstone.

  11. Interactions between wolves and female grizzly bears with cubs in Yellowstone National Park

    Science.gov (United States)

    Gunther, Kerry A.; Smith, Douglas W.

    2004-01-01

    Gray wolves (Canis lupus) were extirpated from Yellowstone National Park (YNP) by the 1920s through predator control actions (Murie 1940,Young and Goldman 1944, Weaver 1978), then reintroduced into the park from 1995 to 1996 to restore ecological integrity and adhere to legal mandates (Bangs and Fritts 1996, Phillips and Smith 1996, Smith et al. 2000). Prior to reintroduction, the potential effects of wolves on the region’s threatened grizzly bear (Ursus arctos) population were evaluated (Servheen and Knight 1993). In areas where wolves and grizzly bears are sympatric, interspecific killing by both species occasionally occurs (Ballard 1980, 1982; Hayes and Baer 1992). Most agonistic interactions between wolves and grizzly bears involve defense of young or competition for carcasses (Murie 1944, 1981; Ballard 1982; Hornbeck and Horejsi 1986; Hayes and Mossop 1987; Kehoe 1995; McNulty et al. 2001). Servheen and Knight (1993) predicted that reintroduced wolves could reduce the frequency of winter-killed and disease-killed ungulates available for bears to scavenge, and that grizzly bears would occasionally usurp wolf-killed ungulate carcasses. Servheen and Knight (1993) hypothesized that interspecific killing and competition for carcasses would have little or no population level effect on either species.

  12. Genetic analysis of individual origins supports isolation of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles; Kendall, Katherine C.; Gunther, Kerry A.; Moody, David S.; Frey, Kevin L.; Paetkau, David

    2010-01-01

    The Greater Yellowstone Ecosystem (GYE) supports the southernmost of the 2 largest remaining grizzly bear (Ursus arctos) populations in the contiguous United States. Since the mid-1980s, this population has increased in numbers and expanded in range. However, concerns for its long-term genetic health remain because of its presumed continued isolation. To test the power of genetic methods for detecting immigrants, we generated 16-locus microsatellite genotypes for 424 individual grizzly bears sampled in the GYE during 1983–2007. Genotyping success was high (90%) and varied by sample type, with poorest success (40%) for hair collected from mortalities found ≥1 day after death. Years of storage did not affect genotyping success. Observed heterozygosity was 0.60, with a mean of 5.2 alleles/marker. We used factorial correspondence analysis (Program GENETIX) and Bayesian clustering (Program STRUCTURE) to compare 424 GYE genotypes with 601 existing genotypes from grizzly bears sampled in the Northern Continental Divide Ecosystem (NCDE) (FST  =  0.096 between GYE and NCDE). These methods correctly classified all sampled individuals to their population of origin, providing no evidence of natural movement between the GYE and NCDE. Analysis of 500 simulated first-generation crosses suggested that over 95% of such bears would also be detectable using our 16-locus data set. Our approach provides a practical method for detecting immigration in the GYE grizzly population. We discuss estimates for the proportion of the GYE population sampled and prospects for natural immigration into the GYE.

  13. Serological survey of selected canine viral pathogens and zoonoses in grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) from Alaska.

    Science.gov (United States)

    Chomel, B B; Kasten, R W; Chappuis, G; Soulier, M; Kikuchi, Y

    1998-12-01

    Between 1988 and 1991, 644 serum samples were collected from 480 grizzly bears (Ursus arctos horribilis) and 40 black bears (Ursus americanus) from Alaska, United States of America, and were tested for selected canine viral infections and zoonoses. Antibody prevalence in grizzly bears was 0% for parvovirus, 8.3% (40/480) for distemper, 14% (68/480) for infectious hepatitis, 16.5% (79/480) for brucellosis, 19% (93/480) for tularaemia and 47% (225/478) for trichinellosis. In black bears, prevalence ranged from 0% for distemper and parvovirus to 27.5% for trichinellosis and 32% for tularaemia. Antibody prevalence for brucellosis (2.5%) and tularaemia (32%) were identical for grizzly bears and black bears from the geographical area of interior Alaska. Links between differences in prevalence and the origin of the grizzly bears were observed. Antibodies to canine distemper virus and infectious hepatitis virus were mainly detected in grizzly bears from Kodiak Island and the Alaskan Peninsula. Brucellosis antibodies were prevalent in grizzly bears from western and northern Alaska, whereas tularaemia antibodies were detected in grizzly bears from interior Alaska and the Arctic. There was a strong gradient for antibodies to Trichinella spp. from southern to northern Alaska. For most diseases, antibody prevalence increased with age. However, for several infections, no antibodies were detected in grizzly bears aged from 0 to 2 years, in contrast to the presence of those infections in black bears. Grizzly bears served as excellent sentinels for surveillance of zoonotic infections in wildlife in Alaska.

  14. The impact of roads on the demography of grizzly bears in Alberta.

    Directory of Open Access Journals (Sweden)

    John Boulanger

    Full Text Available One of the principal factors that have reduced grizzly bear populations has been the creation of human access into grizzly bear habitat by roads built for resource extraction. Past studies have documented mortality and distributional changes of bears relative to roads but none have attempted to estimate the direct demographic impact of roads in terms of both survival rates, reproductive rates, and the interaction of reproductive state of female bears with survival rate. We applied a combination of survival and reproductive models to estimate demographic parameters for threatened grizzly bear populations in Alberta. Instead of attempting to estimate mean trend we explored factors which caused biological and spatial variation in population trend. We found that sex and age class survival was related to road density with subadult bears being most vulnerable to road-based mortality. A multi-state reproduction model found that females accompanied by cubs of the year and/or yearling cubs had lower survival rates compared to females with two year olds or no cubs. A demographic model found strong spatial gradients in population trend based upon road density. Threshold road densities needed to ensure population stability were estimated to further refine targets for population recovery of grizzly bears in Alberta. Models that considered lowered survival of females with dependant offspring resulted in lower road density thresholds to ensure stable bear populations. Our results demonstrate likely spatial variation in population trend and provide an example how demographic analysis can be used to refine and direct conservation measures for threatened species.

  15. Grizzly bear (Ursus arctos horribilis) locomotion: gaits and ground reaction forces.

    Science.gov (United States)

    Shine, Catherine L; Penberthy, Skylar; Robbins, Charles T; Nelson, O Lynne; McGowan, Craig P

    2015-10-01

    Locomotion of plantigrade generalists has been relatively little studied compared with more specialised postures even though plantigrady is ancestral among quadrupeds. Bears (Ursidae) are a representative family for plantigrade carnivorans, they have the majority of the morphological characteristics identified for plantigrade species, and they have the full range of generalist behaviours. This study compared the locomotion of adult grizzly bears (Ursus arctos horribilis Linnaeus 1758), including stride parameters, gaits and analysis of three-dimensional ground reaction forces, with that of previously studied quadrupeds. At slow to moderate speeds, grizzly bears use walks, running walks and canters. Vertical ground reaction forces demonstrated the typical M-shaped curve for walks; however, this was significantly more pronounced in the hindlimb. The rate of force development was also significantly higher for the hindlimbs than for the forelimbs at all speeds. Mediolateral forces were significantly higher than would be expected for a large erect mammal, almost to the extent of a sprawling crocodilian. There may be morphological or energetic explanations for the use of the running walk rather than the trot. The high medial forces (produced from a lateral push by the animal) could be caused by frontal plane movement of the carpus and elbow by bears. Overall, while grizzly bears share some similarities with large cursorial species, their locomotor kinetics have unique characteristics. Additional studies are needed to determine whether these characters are a feature of all bears or plantigrade species.

  16. Possible effects of elk harvest on fall distribution of grizzly bears in the Greater Yellowstone Ecosystem

    Science.gov (United States)

    Haroldson, M.A.; Schwartz, C.C.; Cherry, S.; Moody, D.

    2004-01-01

     The tradition of early elk (Cervus elaphus) hunting seasons adjacent to Yellowstone National Park (YNP), USA, provides grizzly bears (Ursus arctos horribilis) with ungulate remains left by hunters. We investigated the fall (Aug–Oct) distribution of grizzly bears relative to the boundaries of YNP and the opening of September elk hunting seasons. Based on results from exact tests of conditional independence, we estimated the odds of radiomarked bears being outside YNP during the elk hunt versus before the hunt. Along the northern boundary, bears were 2.40 times more likely to be outside YNP during the hunt in good whitebark pine (Pinus albicaulis) seed-crop years and 2.72 times more likely in poor seed-crop years. The level of confidence associated with 1-sided confidence intervals with a lower endpoint of 1 was approximately 94% in good seed-crop years and 61% in poor years. Along the southern boundary of YNP, radiomarked bears were 2.32 times more likely to be outside the park during the hunt in good whitebark pine seed-crop years and 4.35 times more likely in poor seed-crop years. The level of confidence associated with 1-sided confidence intervals with a lower endpoint of 1 was approximately 93% in both cases. Increased seasonal bear densities and human presence in early hunt units increases potential for conflicts between bears and hunters. Numbers of reported hunting-related grizzly bear mortalities have increased in the Greater Yellowstone Ecosystem (GYE) during the last decade, and nearly half of this increase is due to bear deaths occurring in early hunt units during September. Human-caused grizzly bear mortality thresholds established by the U.S. Fish and Wildlife Service (USFWS) have not been exceeded in recent years. This is because agency actions have reduced other sources of human-caused mortalities, and because population parameters that mortality thresholds are based on have increased. Agencies must continue to monitor and manage hunter

  17. Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling.

    Directory of Open Access Journals (Sweden)

    Michael A Sawaya

    Full Text Available We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos and black bear (U. americanus populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears (N= 73.5, 95% CI = 64-94 in 2006; N= 50.4, 95% CI = 49-59 in 2008 and black bears (N= 62.6, 95% CI = 51-89 in 2006; N= 81.8, 95% CI = 72-102 in 2008 in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males (λ= 0.93, 95% CI = 0.74-1.17 and females (λ= 0.90, 95% CI = 0.67-1.20 using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains.

  18. Estimating grizzly and black bear population abundance and trend in Banff National Park using noninvasive genetic sampling.

    Science.gov (United States)

    Sawaya, Michael A; Stetz, Jeffrey B; Clevenger, Anthony P; Gibeau, Michael L; Kalinowski, Steven T

    2012-01-01

    We evaluated the potential of two noninvasive genetic sampling methods, hair traps and bear rub surveys, to estimate population abundance and trend of grizzly (Ursus arctos) and black bear (U. americanus) populations in Banff National Park, Alberta, Canada. Using Huggins closed population mark-recapture models, we obtained the first precise abundance estimates for grizzly bears (N= 73.5, 95% CI = 64-94 in 2006; N= 50.4, 95% CI = 49-59 in 2008) and black bears (N= 62.6, 95% CI = 51-89 in 2006; N= 81.8, 95% CI = 72-102 in 2008) in the Bow Valley. Hair traps had high detection rates for female grizzlies, and male and female black bears, but extremely low detection rates for male grizzlies. Conversely, bear rubs had high detection rates for male and female grizzlies, but low rates for black bears. We estimated realized population growth rates, lambda, for grizzly bear males (λ= 0.93, 95% CI = 0.74-1.17) and females (λ= 0.90, 95% CI = 0.67-1.20) using Pradel open population models with three years of bear rub data. Lambda estimates are supported by abundance estimates from combined hair trap/bear rub closed population models and are consistent with a system that is likely driven by high levels of human-caused mortality. Our results suggest that bear rub surveys would provide an efficient and powerful means to inventory and monitor grizzly bear populations in the Central Canadian Rocky Mountains.

  19. Density, distribution, and genetic structure of grizzly bears in the Cabinet-Yaak Ecosystem

    Science.gov (United States)

    Macleod, Amy C.; Boyd, Kristina L; Boulanger, John; Royle, J. Andrew; Kasworm, Wayne F.; Paetkau, David; Proctor, Michael F; Annis, Kim; Graves, Tabitha A.

    2016-01-01

    The conservation status of the 2 threatened grizzly bear (Ursus arctos) populations in the Cabinet-Yaak Ecosystem (CYE) of northern Montana and Idaho had remained unchanged since designation in 1975; however, the current demographic status of these populations was uncertain. No rigorous data on population density and distribution or analysis of recent population genetic structure were available to measure the effectiveness of conservation efforts. We used genetic detection data from hair corral, bear rub, and opportunistic sampling in traditional and spatial capture–recapture models to generate estimates of abundance and density of grizzly bears in the CYE. We calculated mean bear residency on our sampling grid from telemetry data using Huggins and Pledger models to estimate the average number of bears present and to correct our superpopulation estimates for lack of geographic closure. Estimated grizzly bear abundance (all sex and age classes) in the CYE in 2012 was 48–50 bears, approximately half the population recovery goal. Grizzly bear density in the CYE (4.3–4.5 grizzly bears/1,000 km2) was among the lowest of interior North American populations. The sizes of the Cabinet (n = 22–24) and Yaak (n = 18–22) populations were similar. Spatial models produced similar estimates of abundance and density with comparable precision without requiring radio-telemetry data to address assumptions of geographic closure. The 2 populations in the CYE were demographically and reproductively isolated from each other and the Cabinet population was highly inbred. With parentage analysis, we documented natural migrants to the Cabinet and Yaak populations by bears born to parents in the Selkirk and Northern Continental Divide populations. These events supported data from other sources suggesting that the expansion of neighboring populations may eventually help sustain the CYE populations. However, the small size, isolation, and inbreeding documented by this study

  20. Yellowstone grizzly bear mortality, human habituation, and whitebark pine seed crops

    Science.gov (United States)

    Mattson, David J.; Blanchard, Bonnie M.; Knight, Richard R.

    1992-01-01

    The Yellowstone grizzly bear (Ursus arctos horribilis) population may be extirpated during the next 100-200 years unless mortality rates stabilize and remain at acceptable low levels. Consequently, we analyzed relationships between Yellowstone grizzly bear mortality and frequency of human habituation among bears and size of the whitebark pine (Pinus albicaulis) seed crop. During years of large seed crops, bears used areas within 5 km of roads and 8 km of developments half as intensively as during years of small seed crops because whitebark pine's high elevation distribution is typically remote from human facilities. On average, management trappings of bears were 6.2 times higher, mortality of adult females 2.3 times higher, and mortality of subadult males 3.3 times higher during years of small seed crops. We hypothesize that high mortality of adult females and subadult males during small seed crop years was a consequence of their tendency to range closest (of all sex-age cohorts) to human facilities; they also had a higher frequency of human habituation compared with adult males. We also hypothesize that low morality among subadult females during small seed crop years was a result of fewer energetic stressors compared with adult females and greater familiarity with their range compared with subadult males; mortality was low even though they ranged close to humans and exhibited a high frequency of human habituation. Human-habituated and food-conditioned bears were 2.9 times as likely to range within 4 km of developments and 3.1 times as often killed by humans compared with nonhabituated bears. We argue that destruction of habituated bears that use native foods near humans results in a decline in the overall ability of bears to use available habitat; and that the number and extent of human facilities in occupied grizzly bear habitat needs to be minimized unless habituated bears are preserved and successful ways to manage the associated risks to humans are developed.

  1. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Science.gov (United States)

    Bjornlie, Daniel D; Van Manen, Frank T; Ebinger, Michael R; Haroldson, Mark A; Thompson, Daniel J; Costello, Cecily M

    2014-01-01

    Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem (GYE), recent decline of whitebark pine (WBP; Pinus albicaulis), an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  2. Whitebark pine, population density, and home-range size of grizzly bears in the greater yellowstone ecosystem.

    Directory of Open Access Journals (Sweden)

    Daniel D Bjornlie

    Full Text Available Changes in life history traits of species can be an important indicator of potential factors influencing populations. For grizzly bears (Ursus arctos in the Greater Yellowstone Ecosystem (GYE, recent decline of whitebark pine (WBP; Pinus albicaulis, an important fall food resource, has been paired with a slowing of population growth following two decades of robust population increase. These observations have raised questions whether resource decline or density-dependent processes may be associated with changes in population growth. Distinguishing these effects based on changes in demographic rates can be difficult. However, unlike the parallel demographic responses expected from both decreasing food availability and increasing population density, we hypothesized opposing behavioral responses of grizzly bears with regard to changes in home-range size. We used the dynamic changes in food resources and population density of grizzly bears as a natural experiment to examine hypotheses regarding these potentially competing influences on grizzly bear home-range size. We found that home-range size did not increase during the period of whitebark pine decline and was not related to proportion of whitebark pine in home ranges. However, female home-range size was negatively associated with an index of population density. Our data indicate that home-range size of grizzly bears in the GYE is not associated with availability of WBP, and, for female grizzly bears, increasing population density may constrain home-range size.

  3. Use of pine nuts by grizzly and black bears in the Yellowstone area

    Science.gov (United States)

    Kendall, Katherine C.

    1983-01-01

    The large seeds (pine nuts) of whitebark pine are commonly eaten in the spring (March-May) and fall (September-November) by grizzly and black bears in Yellowstone National Park and adjacent areas (Craighead and Craighead 1972, Blanchard 1978, Mealey 1980) and western Montana (Tisch 1961; J. Sumner and J. J. Craighead, unpubl. rep., Montant Coop. Wildl. Res. Unit, Univ. Montana, Missoula, 1973). Similar nuts from limber pine are eaten by grizzly bears on the east Rocky Mountain Front of northwestern Montana (Schallenberger and Jonkel, annual rep., Border Grizzly Project, Univ. Montana, Missoula, 1980). The nuts of the European stone pine (P. cembra) are an important food for brown bears (U. arctos) throughout the taiga zone in the Soviet Union (Pavlov and Zhdanov 1972, Ustinov 1972, Yazan 1972). Both the production of whitebark pine cones (Forcella 1977, Blanchard 1978, Mealey 1980) and the quantity of nuts consumed by bears vary annually (Mealey 1975, Blancard 1978). Pine nuts are also an important food for red squirrels in whitebark forests. In fall, squirrels remove cones from trees and cache them in middens. Bears as well as other mammalian and avian seed predators compete with squirrels for whitebark nuts (Forcella 1977, Tomback 1977). Confusion about the ripening process of whitebark pine cones has resulted in errors in the literature on the availability of pine nuts as a bear food. Whitebark cones are indehiscent and do not disintegrate (Tomback 1981). Vertebrate foraging probably leaves few, if any, seed-bearing cones on trees by late fall; the cones remaining abscise sometime thereafter (Tomback 1981). Because cones do not abscise or release their seed in fall, bears may obtain pine nuts in 2 ways. Black bears may climb whitebark pine trees and break off cone-bearing brnahces to feed on cones (Tisch 1961, Mealey 1975, Forcella 1977); or both black bears and grizzly bears may raid squirrel caches to feed on pine nuts (Tisch 1961, Craighead and Craighead 1972

  4. Idiosyncratic responses of grizzly bear habitat to climate change based on projected food resource changes.

    Science.gov (United States)

    Roberts, David R; Nielsen, Scott E; Stenhouse, Gordon B

    2014-07-01

    Climate change vulnerability assessments for species of conservation concern often use species distribution and ecological niche modeling to project changes in habitat. One of many assumptions of these approaches is that food web dependencies are consistent in time and environmental space. Species at higher trophic levels that rely on the availability of species at lower trophic levels as food may be sensitive to extinction cascades initiated by changes in the habitat of key food resources. Here we assess climate change vulnerability for Ursus arctos (grizzly bears) in the southern Canadian Rocky Mountains using projected changes to 17 of the most commonly consumed plant food items. We used presence-absence information from 7088 field plots to estimate ecological niches and to project changes in future distributions of each species. Model projections indicated idiosyncratic responses among food items. Many food items persisted or even increased, although several species were found to be vulnerable based on declines or geographic shifts in suitable habitat. These included Hedysarum alpinum (alpine sweet vetch), a critical spring and autumn root-digging resource when little else is available. Potential habitat loss was also identified for three fruiting species of lower importance to bears: Empetrum nigrum (crowberry), Vaccinium scoparium (grouseberry), and Fragaria virginiana (strawberry). A general trend towards uphill migration of bear foods may result in higher vulnerability to bear populations at low elevations, which are also those that are most likely to have human-bear conflict problems. Regardless, a wide diet breadth of grizzly bears, as well as wide environmental niches of most food items, make climate change a much lower threat to grizzly bears than other bear species such as polar bears and panda bears. We cannot exclude, however, future alterations in human behavior and land use resulting from climate change that may reduce survival rates.

  5. Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA

    Science.gov (United States)

    Wilson, S.M.; Madel, M.J.; Mattson, D.J.; Graham, J.M.; Merrill, T.

    2006-01-01

    We used multiple logistic regression to model how different landscape conditions contributed to the probability of human-grizzly bear conflicts on private agricultural ranch lands. We used locations of livestock pastures, traditional livestock carcass disposal areas (boneyards), beehives, and wetland-riparian associated vegetation to model the locations of 178 reported human-grizzly bear conflicts along the Rocky Mountain East Front, Montana, USA during 1986-2001. We surveyed 61 livestock producers in the upper Teton watershed of north-central Montana, to collect spatial and temporal data on livestock pastures, boneyards, and beehives for the same period, accounting for changes in livestock and boneyard management and beehive location and protection, for each season. We used 2032 random points to represent the null hypothesis of random location relative to potential explanatory landscape features, and used Akaike's Information Criteria (AIC/AICC) and Hosmer-Lemeshow goodness-of-fit statistics for model selection. We used a resulting "best" model to map contours of predicted probabilities of conflict, and used this map for verification with an independent dataset of conflicts to provide additional insights regarding the nature of conflicts. The presence of riparian vegetation and distances to spring, summer, and fall sheep or cattle pastures, calving and sheep lambing areas, unmanaged boneyards, and fenced and unfenced beehives were all associated with the likelihood of human-grizzly bear conflicts. Our model suggests that collections of attractants concentrated in high quality bear habitat largely explain broad patterns of human-grizzly bear conflicts on private agricultural land in our study area. ?? 2005 Elsevier Ltd. All rights reserved.

  6. Use of sulfur and nitrogen stable isotopes to determine the importance of whitebark pine nuts to Yellowstone grizzly bears

    Science.gov (United States)

    Felicetti, L.A.; Schwartz, C.C.; Rye, R.O.; Haroldson, M.A.; Gunther, K.A.; Phillips, D.L.; Robbins, C.T.

    2003-01-01

    Whitebark pine (Pinus albicaulis) is a masting species that produces relatively large, fat- and protein-rich nuts that are consumed by grizzly bears (Ursus arctos horribilis). Trees produce abundant nut crops in some years and poor crops in other years. Grizzly bear survival in the Greater Yellowstone Ecosystem is strongly linked to variation in pine-nut availability. Because whitebark pine trees are infected with blister rust (Cronartium ribicola), an exotic fungus that has killed the species throughout much of its range in the northern Rocky Mountains, we used stable isotopes to quantify the importance of this food resource to Yellowstone grizzly bears while healthy populations of the trees still exist. Whitebark pine nuts have a sulfur-isotope signature (9.2 ?? 1.3??? (mean ?? 1 SD)) that is distinctly different from those of all other grizzly bear foods (ranging from 1.9 ?? 1.7??? for all other plants to 3.1 ?? 2.6??? for ungulates). Feeding trials with captive grizzly bears were used to develop relationships between dietary sulfur-, carbon-, and nitrogen-isotope signatures and those of bear plasma. The sulfur and nitrogen relationships were used to estimate the importance of pine nuts to free-ranging grizzly bears from blood and hair samples collected between 1994 and 2001. During years of poor pine-nut availability, 72% of the bears made minimal use of pine nuts. During years of abundant cone availability, 8 ?? 10% of the bears made minimal use of pine nuts, while 67 ?? 19% derived over 51% of their assimilated sulfur and nitrogen (i.e., protein) from pine nuts. Pine nuts and meat are two critically important food resources for Yellowstone grizzly bears.

  7. Comparison of methanol and isopropanol as wash solvents for determination of hair cortisol concentration in grizzly bears and polar bears.

    Science.gov (United States)

    Kroshko, Thomas; Kapronczai, Luciene; Cattet, Marc R L; Macbeth, Bryan J; Stenhouse, Gordon B; Obbard, Martyn E; Janz, David M

    2017-01-01

    Methodological differences among laboratories are recognized as significant sources of variation in quantification of hair cortisol concentration (HCC). An important step in processing hair, particularly when collected from wildlife, is the choice of solvent used to remove or "wash" external hair shaft cortisol prior to quantification of HCC. The present study systematically compared methanol and isopropanol as wash solvents for their efficiency at removing external cortisol without extracting internal hair shaft cortisol in samples collected from free-ranging grizzly bears and polar bears. Cortisol concentrations in solvents and hair were determined in each of one to eight washes of hair with each solvent independently. •There were no significant decreases in internal hair shaft cortisol among all eight washes for either solvent, although methanol removed detectable hair surface cortisol after one wash in grizzly bear hair whereas hair surface cortisol was detected in all eight isopropanol washes.•There were no significant differences in polar bear HCC washed one to eight times with either solvent, but grizzly bear HCC was significantly greater in hair washed with isopropanol compared to methanol.•There were significant differences in HCC quantified using different commercial ELISA kits commonly used for HCC determinations.

  8. Modeling survival: application of the Andersen-Gill model to Yellowstone grizzly bears

    Science.gov (United States)

    Johnson, Christopher J.; Boyce, Mark S.; Schwartz, Charles C.; Haroldson, Mark A.

    2004-01-01

     Wildlife ecologists often use the Kaplan-Meier procedure or Cox proportional hazards model to estimate survival rates, distributions, and magnitude of risk factors. The Andersen-Gill formulation (A-G) of the Cox proportional hazards model has seen limited application to mark-resight data but has a number of advantages, including the ability to accommodate left-censored data, time-varying covariates, multiple events, and discontinuous intervals of risks. We introduce the A-G model including structure of data, interpretation of results, and assessment of assumptions. We then apply the model to 22 years of radiotelemetry data for grizzly bears (Ursus arctos) of the Greater Yellowstone Grizzly Bear Recovery Zone in Montana, Idaho, and Wyoming, USA. We used Akaike's Information Criterion (AICc) and multi-model inference to assess a number of potentially useful predictive models relative to explanatory covariates for demography, human disturbance, and habitat. Using the most parsimonious models, we generated risk ratios, hypothetical survival curves, and a map of the spatial distribution of high-risk areas across the recovery zone. Our results were in agreement with past studies of mortality factors for Yellowstone grizzly bears. Holding other covariates constant, mortality was highest for bears that were subjected to repeated management actions and inhabited areas with high road densities outside Yellowstone National Park. Hazard models developed with covariates descriptive of foraging habitats were not the most parsimonious, but they suggested that high-elevation areas offered lower risks of mortality when compared to agricultural areas.

  9. Immobilization of grizzly bears (Ursus arctos) with dexmedetomidine, tiletamine, and zolazepam.

    Science.gov (United States)

    Teisberg, Justin E; Farley, Sean D; Nelson, O Lynne; Hilderbrand, Grant V; Madel, Michael J; Owen, Patricia A; Erlenbach, Joy A; Robbins, Charles T

    2014-01-01

    Safe and effective immobilization of grizzly bears (Ursus arctos) is essential for research and management. Fast induction of anesthesia, maintenance of healthy vital rates, and predictable recoveries are priorities. From September 2010 to May 2012, we investigated these attributes in captive and wild grizzly bears anesthetized with a combination of a reversible α2 agonist (dexmedetomidine [dexM], the dextrorotatory enantiomer of medetomidine) and a nonreversible N-methyl-d-aspartate (NMDA) agonist and tranquilizer (tiletamine and zolazepam [TZ], respectively). A smaller-than-expected dose of the combination (1.23 mg tiletamine, 1.23 mg zolazepam, and 6.04 µg dexmedetomidine per kg bear) produced reliable, fast ataxia (3.7 ± 0.5 min, x̄±SE) and workable anesthesia (8.1 ± 0.6 min) in captive adult grizzly bears. For wild bears darted from a helicopter, a dose of 2.06 mg tiletamine, 2.06 mg zolazepam, and 10.1 µg dexmedetomidine/kg produced ataxia in 2.5 ± 0.3 min and anesthesia in 5.5 ± 1.0 min. Contrary to published accounts of bear anesthesia with medetomidine, tiletamine, and zolazepam, this combination did not cause hypoxemia or hypoventilation, although mild bradycardia (bears during the active season. With captive bears, effective dose rates during hibernation were approximately half those during the active season. The time to first signs of recovery after the initial injection of dexMTZ was influenced by heart rate (Pgrizzly bears, especially during helicopter capture operations.

  10. The Bear Facts: Implications of Whitebark Pine Loss for Yellowstone Grizzlies

    OpenAIRE

    Willcox, Louisa

    2009-01-01

    Whitebark pine is a foundation species, and barometer of the health of high elevation forests ecosystems in the West. It provides food and cover for numerous wildlife species, including the Clark’s nutcracker, crossbill, grosbeak, red squirrel and chipmunk. Whitebark pine is particularly important in the Greater Yellowstone Ecosystem (GYE), where it provides an essential food source for the imperiled Yellowstone grizzly bear. We will review the current scientific knowledge about the relations...

  11. Insights into the regulation of muscle metabolism and growth in mice and hibernating grizzly bears

    OpenAIRE

    Mugahid (Megahed), Douaa (Doaa)

    2015-01-01

    Mechanotransduction plays an important role in the regulation of muscle growth and metabolic signalling in striated muscle. Muscle disuse reduces mechanical input to the muscle, which results in a loss of muscle mass. Here I describe how titin's mechanically activated kinase domain affects muscle growth and metabolism via p62 and Akt signalling. I also demonstrate how changes in metabolic and growth signalling in hibernating grizzly bear help maintain muscle mass under conditio...

  12. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  13. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears.

    Science.gov (United States)

    Costello, Cecily M; Cain, Steven L; Pils, Shannon; Frattaroli, Leslie; Haroldson, Mark A; van Manen, Frank T

    2016-01-01

    When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004-2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46-47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in this

  14. Diet and macronutrient optimization in wild ursids: A comparison of grizzly bears with sympatric and allopatric black bears

    Science.gov (United States)

    Costello, Cecily M; Cain, Steven L; Pils, Shannon R; Frattaroli, Leslie; Haroldson, Mark A.; van Manen, Frank T.

    2016-01-01

    When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos) and black bears (Ursus americanus) in Grand Teton National Park during 2004–2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days) led to over-consumption of protein, and 1 diet (3% of days) led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates), which accounted for 46–47% of daily energy for both species. As predicted: 1) daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2) diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3) mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4) allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among bears in

  15. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears.

    Directory of Open Access Journals (Sweden)

    Cecily M Costello

    Full Text Available When fed ad libitum, ursids can maximize mass gain by selecting mixed diets wherein protein provides 17 ± 4% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition. By visiting locations of 37 individuals during 274 bear-days, we documented foods consumed by grizzly (Ursus arctos and black bears (Ursus americanus in Grand Teton National Park during 2004-2006. Based on published nutritional data, we estimated foods and macronutrients as percentages of daily energy intake. Using principal components and cluster analyses, we identified 14 daily diet types. Only 4 diets, accounting for 21% of days, provided protein levels within the optimal range. Nine diets (75% of days led to over-consumption of protein, and 1 diet (3% of days led to under-consumption. Highest protein levels were associated with animal matter (i.e., insects, vertebrates, which accounted for 46-47% of daily energy for both species. As predicted: 1 daily diets dominated by high-energy vertebrates were positively associated with grizzly bears and mean percent protein intake was positively associated with body mass; 2 diets dominated by low-protein fruits were positively associated with smaller-bodied black bears; and 3 mean protein was highest during spring, when high-energy plant foods were scarce, however it was also higher than optimal during summer and fall. Contrary to our prediction: 4 allopatric black bears did not exhibit food selection for high-energy foods similar to grizzly bears. Although optimal gain of body mass was typically constrained, bears usually opted for the energetically superior trade-off of consuming high-energy, high-protein foods. Given protein digestion efficiency similar to obligate carnivores, this choice likely supported mass gain, consistent with studies showing monthly increases in percent body fat among

  16. Implications of a high-energy and low-protein diet on the body composition, fitness, and competitive abilities of black (Ursus americanus) and grizzly (Ursus arctos) bears

    National Research Council Canada - National Science Library

    McLellan, B.N

    2011-01-01

    ...% of the summer diet of both species were fruits that are low in protein. Body composition measurements showed bears loose fat during spring, gained fat during summer, and grizzly bears were leaner than black bears...

  17. Plant consumption by grizzly bears reduces biomagnification of salmon-derived polychlorinated biphenyls, polybrominated diphenyl ethers, and organochlorine pesticides.

    Science.gov (United States)

    Christensen, Jennie R; Yunker, Mark B; MacDuffee, Misty; Ross, Peter S

    2013-04-01

    The present study characterizes the uptake and loss of persistent organic pollutants (POPs) in grizzly bears (Ursus arctos horribilis) by sampling and analyzing their terrestrial and marine foods and fecal material from a remote coastal watershed in British Columbia, Canada. The authors estimate that grizzly bears consume 341 to 1,120 µg of polychlorinated biphenyls (PCBs) and 3.9 to 33 µg of polybrominated diphenyl ethers daily in the fall when they have access to an abundant supply of returning salmon. The authors also estimate that POP elimination by grizzly bears through defecation is very low following salmon consumption (typically 100% for PCBs and organochlorine pesticides). Excretion of individual POPs is largely driven by a combination of fugacity (differences between bear and food concentrations) and the digestibility of the food. The results of the present study are substantiated by a principal components analysis, which also demonstrates a strong role for log KOW in governing the excretion of different POPs in grizzly bears. Collectively, the present study's results reveal that grizzly bears experience a vegetation-associated drawdown of POPs previously acquired through the consumption of salmon, to such an extent that net biomagnification is reduced.

  18. Linking landscape characteristics to local grizzly bear abundance using multiple detection methods in a hierarchical model

    Science.gov (United States)

    Graves, T.A.; Kendall, K.C.; Royle, J. Andrew; Stetz, J.B.; Macleod, A.C.

    2011-01-01

    Few studies link habitat to grizzly bear Ursus arctos abundance and these have not accounted for the variation in detection or spatial autocorrelation. We collected and genotyped bear hair in and around Glacier National Park in northwestern Montana during the summer of 2000. We developed a hierarchical Markov chain Monte Carlo model that extends the existing occupancy and count models by accounting for (1) spatially explicit variables that we hypothesized might influence abundance; (2) separate sub-models of detection probability for two distinct sampling methods (hair traps and rub trees) targeting different segments of the population; (3) covariates to explain variation in each sub-model of detection; (4) a conditional autoregressive term to account for spatial autocorrelation; (5) weights to identify most important variables. Road density and per cent mesic habitat best explained variation in female grizzly bear abundance; spatial autocorrelation was not supported. More female bears were predicted in places with lower road density and with more mesic habitat. Detection rates of females increased with rub tree sampling effort. Road density best explained variation in male grizzly bear abundance and spatial autocorrelation was supported. More male bears were predicted in areas of low road density. Detection rates of males increased with rub tree and hair trap sampling effort and decreased over the sampling period. We provide a new method to (1) incorporate multiple detection methods into hierarchical models of abundance; (2) determine whether spatial autocorrelation should be included in final models. Our results suggest that the influence of landscape variables is consistent between habitat selection and abundance in this system. ?? 2011 The Authors. Animal Conservation ?? 2011 The Zoological Society of London.

  19. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

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    Mark A Edwards

    Full Text Available The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

  20. Home range size variation in female arctic grizzly bears relative to reproductive status and resource availability.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E; Nagy, John A

    2013-01-01

    The area traversed in pursuit of resources defines the size of an animal's home range. For females, the home range is presumed to be a function of forage availability. However, the presence of offspring may also influence home range size due to reduced mobility, increased nutritional need, and behavioral adaptations of mothers to increase offspring survival. Here, we examine the relationship between resource use and variation in home range size for female barren-ground grizzly bears (Ursus arctos) of the Mackenzie Delta region in Arctic Canada. We develop methods to test hypotheses of home range size that address selection of cover where cover heterogeneity is low, using generalized linear mixed-effects models and an information-theoretic approach. We found that the reproductive status of female grizzlies affected home range size but individually-based spatial availability of highly selected cover in spring and early summer was a stronger correlate. If these preferred covers in spring and early summer, a period of low resource availability for grizzly bears following den-emergence, were patchy and highly dispersed, females travelled farther regardless of the presence or absence of offspring. Increased movement to preferred covers, however, may result in greater risk to the individual or family.

  1. Population fragmentation and inter-ecosystem movements of grizzly bears in Western Canada and the Northern United States

    Science.gov (United States)

    Proctor, M.F.; Paetkau, David; McLellan, B.N.; Stenhouse, G.B.; Kendall, K.C.; Mace, R.D.; Kasworm, W.F.; Servheen, C.; Lausen, C.L.; Gibeau, M.L.; Wakkinen, W.L.; Haroldson, M.A.; Mowat, G.; Apps, C.D.; Ciarniello, L.M.; Barclay, R.M.R.; Boyce, M.S.; Schwartz, C.C.; Strobeck, C.

    2012-01-01

    Population fragmentation compromises population viability, reduces a species ability to respond to climate change, and ultimately may reduce biodiversity. We studied the current state and potential causes of fragmentation in grizzly bears over approximately 1,000,000 km 2 of western Canada, the northern United States (US), and southeast Alaska. We compiled much of our data from projects undertaken with a variety of research objectives including population estimation and trend, landscape fragmentation, habitat selection, vital rates, and response to human development. Our primary analytical techniques stemmed from genetic analysis of 3,134 bears, supplemented with radiotelemetry data from 792 bears. We used 15 locus microsatellite data coupled withmeasures of genetic distance, isolation-by-distance (IBD) analysis, analysis of covariance (ANCOVA), linear multiple regression, multi-factorial correspondence analysis (to identify population divisions or fractures with no a priori assumption of group membership), and population-assignment methods to detect individual migrants between immediately adjacent areas. These data corroborated observations of inter-area movements from our telemetry database. In northern areas, we found a spatial genetic pattern of IBD, although there was evidence of natural fragmentation from the rugged heavily glaciated coast mountains of British Columbia (BC) and the Yukon. These results contrasted with the spatial pattern of fragmentation in more southern parts of their distribution. Near the Canada-US border area, we found extensive fragmentation that corresponded to settled mountain valleys andmajor highways. Genetic distances across developed valleys were elevated relative to those across undeveloped valleys in central and northern BC. In disturbed areas, most inter-area movements detected were made by male bears, with few female migrants identified. North-south movements within mountain ranges (Mts) and across BC Highway 3 were more common

  2. Grizzly bear management in Yellowstone National Park: The heart of recovery in the Yellowstone Ecosystem

    Science.gov (United States)

    Schwartz, C.C.; Gunther, K.; McCullough, Dale R.; Kaji, Koichi; Yamanaka, Masami

    2006-01-01

    Grizzly bear (Ursus arctos) management in the Greater Yellowstone Ecosystem (GYE) in the past quarter century has resulted in more than doubling of the population from around 200 to more than 500, expansion of range back into habitats where the bear has extirpated more than a century ago, and a move toward removal from the U.S. Endangered Species list. At the center of this success story are the management programs in Yellowstone National Park (YNP). Regulations that restrict human activity, camping, and food storage, elimination of human food and garbage as attractants, and ranger attendance of roadside bears have all resulted in the population of grizzlies in YNP approaching carrying capacity. Recent studies suggest, however, that YNP alone is too small to support the current population, making management beyond the park boundary important and necessary to the demographics of the population as a whole. Demographic analyses suggest a source-sink dynamic exists within the GYE, with YNP and lands outside the park within the Grizzly Bear Recovery Zone (RZ) representing source habitats, whereas lands beyond the RZ constitute sinks. The source-sink demography in the GYE is indicative of carnivore conservation issues worldwide where many national parks or preserves designed to protect out natural resources are inadequate in size or shape to provide all necessary life history requirements for these wide-ranging species. Additionally, wide-ranging behavior and long-distance dispersal seem inherent to large carnivores, so mortality around the edges is virtually inevitable, and conservation in the GYE is inextricably linked to management regimes not only within YNP, but within the GYE as a whole. We discuss those needs here.

  3. Hibernation-associated changes in persistent organic pollutant (POP) levels and patterns in British Columbia grizzly bears (ursus arctos horribilis).

    Science.gov (United States)

    Christensen, Jennie R; MacDuffee, Misty; Yunker, Mark B; Ross, Peter S

    2007-03-15

    We hypothesized that depleted fat reserves in grizzly bears (Ursus arctos horribilis) following annual hibernation would reveal increases in persistent organic pollutant (POP) concentrations compared to those present in the fall. We obtained fat and hair from British Columbia grizzly bears in early spring 2004 to compare with those collected in fall 2003, with the two tissue types providing contaminant and dietary information, respectively. By correcting for the individual feeding habits of grizzlies using a stable isotope-based approach, we found that polychlorinated biphenyls (sigmaPCBs) increased by 2.21x, polybrominated diphenylethers (sigmaPBDEs) increased by 1.58x, and chlordanes (sigmaCHL) by 1.49x in fat following hibernation. Interestingly, individual POPs elicited a wide range of hibernation-associated concentration effects (e.g., CB-153, 2.25x vs CB-169, 0.00x), resulting in POP pattern convergence in a PCA model of two distinct fall feeding groups (salmon-eating vs non-salmon-eating) into a single spring (post-hibernation) group. Our results suggest that diet dictates contaminant patterns during a feeding phase, while metabolism drives patterns during a fasting phase. This work suggests a duality of POP-associated health risks to hibernating grizzly bears: (1) increased concentrations of some POPs during hibernation; and (2) a potentially prolonged accumulation of water-soluble, highly reactive POP metabolites, since grizzly bears do not excrete during hibernation.

  4. Respect for Grizzly Bears: an Aboriginal Approach for Co-existence and Resilience

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    D. Scott. Slocombe

    2009-06-01

    Full Text Available Aboriginal peoples’ respect for grizzly bear (Ursus arctos is widely acknowledged, but rarely explored, in wildlife management discourse in northern Canada. Practices of respect expressed toward bears were observed and grouped into four categories: terminology, stories, reciprocity, and ritual. In the southwest Yukon, practices in all four categories form a coherent qualitative resource management system that may enhance the resilience of the bear-human system as a whole. This system also demonstrates the possibility of a previously unrecognized human role in maintaining productive riparian ecosystems and salmon runs, potentially providing a range of valued social-ecological outcomes. Practices of respect hold promise for new strategies to manage bear-human interactions, but such successful systems may be irreducibly small scale and place based.

  5. Grizzly bear population vital rates and trend in the Northern Continental Divide Ecosystem, Montana

    Science.gov (United States)

    Mace, R.D.; Carney, D.W.; Chilton-Radandt, T.; Courville, S.A.; Haroldson, M.A.; Harris, R.B.; Jonkel, J.; McLellan, B.; Madel, M.; Manley, T.L.; Schwartz, C.C.; Servheen, C.; Stenhouse, G.; Waller, J.S.; Wenum, E.

    2012-01-01

    We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892–0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate (mx) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ > 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued.

  6. Impacts of rural development on Yellowstone wildlife: linking grizzly bear Ursus arctos demographics with projected residential growth

    Science.gov (United States)

    Schwartz, Charles C.; Gude, Patricia H.; Landenburger, Lisa; Haroldson, Mark A.; Podruzny, Shannon

    2012-01-01

    Exurban development is consuming wildlife habitat within the Greater Yellowstone Ecosystem with potential consequences to the long-term conservation of grizzly bears Ursus arctos. We assessed the impacts of alternative future land-use scenarios by linking an existing regression-based simulation model predicting rural development with a spatially explicit model that predicted bear survival. Using demographic criteria that predict population trajectory, we portioned habitats into either source or sink, and projected the loss of source habitat associated with four different build out (new home construction) scenarios through 2020. Under boom growth, we predicted that 12 km2 of source habitat were converted to sink habitat within the Grizzly Bear Recovery Zone (RZ), 189 km2 were converted within the current distribution of grizzly bears outside of the RZ, and 289 km2 were converted in the area outside the RZ identified as suitable grizzly bear habitat. Our findings showed that extremely low densities of residential development created sink habitats. We suggest that tools, such as those outlined in this article, in addition to zoning and subdivision regulation may prove more practical, and the most effective means of retaining large areas of undeveloped land and conserving grizzly bear source habitat will likely require a landscape-scale approach. We recommend a focus on land conservation efforts that retain open space (easements, purchases and trades) coupled with the implementation of ‘bear community programmes’ on an ecosystem wide basis in an effort to minimize human-bear conflicts, minimize management-related bear mortalities associated with preventable conflicts and to safeguard human communities. Our approach has application to other species and areas, and it has illustrated how spatially explicit demographic models can be combined with models predicting land-use change to help focus conservation priorities.

  7. Macronutrient optimization and seasonal diet mixing in a large omnivore, the grizzly bear: a geometric analysis.

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    Sean C P Coogan

    Full Text Available Nutrient balance is a strong determinant of animal fitness and demography. It is therefore important to understand how the compositions of available foods relate to required balance of nutrients and habitat suitability for animals in the wild. These relationships are, however, complex, particularly for omnivores that often need to compose balanced diets by combining their intake from diverse nutritionally complementary foods. Here we apply geometric models to understand how the nutritional compositions of foods available to an omnivorous member of the order Carnivora, the grizzly bear (Ursus arctos L., relate to optimal macronutrient intake, and assess the seasonal nutritional constraints on the study population in west-central Alberta, Canada. The models examined the proportion of macronutrients that bears could consume by mixing their diet from food available in each season, and assessed the extent to which bears could consume the ratio of protein to non-protein energy previously demonstrated using captive bears to optimize mass gain. We found that non-selective feeding on ungulate carcasses provided a non-optimal macronutrient balance with surplus protein relative to fat and carbohydrate, reflecting adaptation to an omnivorous lifestyle, and that optimization through feeding selectively on different tissues of ungulate carcasses is unlikely. Bears were, however, able to dilute protein intake to an optimal ratio by mixing their otherwise high-protein diet with carbohydrate-rich fruit. Some individual food items were close to optimally balanced in protein to non-protein energy (e.g. Hedysarum alpinum roots, which may help explain their dietary prevalence. Ants may be consumed particularly as a source of lipids. Overall, our analysis showed that most food available to bears in the study area were high in protein relative to lipid or carbohydrate, suggesting the lack of non-protein energy limits the fitness (e.g. body size and reproduction and

  8. Macronutrient optimization and seasonal diet mixing in a large omnivore, the grizzly bear: a geometric analysis.

    Science.gov (United States)

    Coogan, Sean C P; Raubenheimer, David; Stenhouse, Gordon B; Nielsen, Scott E

    2014-01-01

    Nutrient balance is a strong determinant of animal fitness and demography. It is therefore important to understand how the compositions of available foods relate to required balance of nutrients and habitat suitability for animals in the wild. These relationships are, however, complex, particularly for omnivores that often need to compose balanced diets by combining their intake from diverse nutritionally complementary foods. Here we apply geometric models to understand how the nutritional compositions of foods available to an omnivorous member of the order Carnivora, the grizzly bear (Ursus arctos L.), relate to optimal macronutrient intake, and assess the seasonal nutritional constraints on the study population in west-central Alberta, Canada. The models examined the proportion of macronutrients that bears could consume by mixing their diet from food available in each season, and assessed the extent to which bears could consume the ratio of protein to non-protein energy previously demonstrated using captive bears to optimize mass gain. We found that non-selective feeding on ungulate carcasses provided a non-optimal macronutrient balance with surplus protein relative to fat and carbohydrate, reflecting adaptation to an omnivorous lifestyle, and that optimization through feeding selectively on different tissues of ungulate carcasses is unlikely. Bears were, however, able to dilute protein intake to an optimal ratio by mixing their otherwise high-protein diet with carbohydrate-rich fruit. Some individual food items were close to optimally balanced in protein to non-protein energy (e.g. Hedysarum alpinum roots), which may help explain their dietary prevalence. Ants may be consumed particularly as a source of lipids. Overall, our analysis showed that most food available to bears in the study area were high in protein relative to lipid or carbohydrate, suggesting the lack of non-protein energy limits the fitness (e.g. body size and reproduction) and population density

  9. The effects of automated scatter feeders on captive grizzly bear activity budgets.

    Science.gov (United States)

    Andrews, Nathan L P; Ha, James C

    2014-01-01

    Although captive bears are popular zoo attractions, they are known to exhibit high levels of repetitive behaviors (RBs). These behaviors have also made them particularly popular subjects for welfare research. To date, most research on ursid welfare has focused on various feeding methods that seek to increase time spent searching for, extracting, or consuming food. Prior research indicates an average of a 50% reduction in RBs when attempts are successful and, roughly, a 50% success rate across studies. This research focused on decreasing time spent in an RB while increasing the time spent active by increasing time spent searching for, extracting, and consuming food. The utility of timed, automated scatter feeders was examined for use with captive grizzly bears (Ursis arctos horribilis). Findings include a significant decrease in time spent in RB and a significant increase in time spent active while the feeders were in use. Further, the bears exhibited a wider range of behaviors and a greater use of their enclosure.

  10. Grizzly bear monitoring by the Heiltsuk people as a crucible for First Nation conservation practice

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    William G. Housty

    2014-06-01

    Full Text Available Guided by deeply held cultural values, First Nations in Canada are rapidly regaining legal authority to manage natural resources. We present a research collaboration among academics, tribal government, provincial and federal government, resource managers, conservation practitioners, and community leaders supporting First Nation resource authority and stewardship. First, we present results from a molecular genetics study of grizzly bears inhabiting an important conservation area within the territory of the Heiltsuk First Nation in coastal British Columbia. Noninvasive hair sampling occurred between 2006 and 2009 in the Koeye watershed, a stronghold for grizzly bears, salmon, and Heiltsuk people. Molecular demographic analyses revealed a regionally significant population of bears, which congregate at the Koeye each salmon-spawning season. There was a minimum of 57 individual bears detected during the study period. Results also pointed to a larger than expected source geography for salmon-feeding bears in the study area (> 1000 km², as well as early evidence of a declining trend in the bear population potentially explained by declining salmon numbers. Second, we demonstrate and discuss the power of integrating scientific research with a culturally appropriate research agenda developed by indigenous people. Guided explicitly by principles from Gvi'ilas or customary law, this research methodology is coupled with Heiltsuk culture, enabling results of applied conservation science to involve and resonate with tribal leadership in ways that have eluded previous scientific endeavors. In this context, we discuss the effectiveness of research partnerships that, from the outset, create both scientific programs and integrated communities of action that can implement change. We argue that indigenous resource management requires collaborative approaches like ours, in which science-based management is embedded within a socially and culturally appropriate

  11. Carnivore re-colonisation: Reality, possibility and a non-equilibrium century for grizzly bears in the southern Yellowstone ecosystem

    Science.gov (United States)

    Pyare, Sanjay; Cain, S.; Moody, D.; Schwartz, C.; Berger, J.

    2004-01-01

    Most large native carnivores have experienced range contractions due to conflicts with humans, although neither rates of spatial collapse nor expansion have been well characterised. In North America, the grizzly bear (Ursus arctos) once ranged from Mexico northward to Alaska, however its range in the continental USA has been reduced by 95-98%. Under the U. S. Endangered Species Act, the Yellowstone grizzly bear population has re-colonised habitats outside Yellowstone National Park. We analysed historical and current records, including data on radio-collared bears, (1) to evaluate changes in grizzly bear distribution in the southern Greater Yellowstone Ecosystem (GYE) over a 100-year period, (2) to utilise historical rates of re-colonisation to project future expansion trends and (3) to evaluate the reality of future expansion based on human limitations and land use. Analysis of distribution in 20-year increments reflects range reduction from south to north (1900-1940) and expansion to the south (1940-2000). Expansion was exponential and the area occupied by grizzly bears doubled approximately every 20 years. A complementary analysis of bear occurrence in Grand Teton National Park also suggests an unprecedented period of rapid expansion during the last 20-30 years. The grizzly bear population currently has re-occupied about 50% of the southern GYE. Based on assumptions of continued protection and ecological stasis, our model suggests total occupancy in 25 years. Alternatively, extrapolation of linear expansion rates from the period prior to protection suggests total occupancy could take > 100 years. Analyses of historical trends can be useful as a restoration tool because they enable a framework and timeline to be constructed to pre-emptively address the social challenges affecting future carnivore recovery. ?? 2004 The Zoological Society of London.

  12. Detecting grizzly bear use of ungulate carcasses using global positioning system telemetry and activity data.

    Science.gov (United States)

    Ebinger, Michael R; Haroldson, Mark A; van Manen, Frank T; Costello, Cecily M; Bjornlie, Daniel D; Thompson, Daniel J; Gunther, Kerry A; Fortin, Jennifer K; Teisberg, Justin E; Pils, Shannon R; White, P J; Cain, Steven L; Cross, Paul C

    2016-07-01

    Global positioning system (GPS) wildlife collars have revolutionized wildlife research. Studies of predation by free-ranging carnivores have particularly benefited from the application of location clustering algorithms to determine when and where predation events occur. These studies have changed our understanding of large carnivore behavior, but the gains have concentrated on obligate carnivores. Facultative carnivores, such as grizzly/brown bears (Ursus arctos), exhibit a variety of behaviors that can lead to the formation of GPS clusters. We combined clustering techniques with field site investigations of grizzly bear GPS locations (n = 732 site investigations; 2004-2011) to produce 174 GPS clusters where documented behavior was partitioned into five classes (large-biomass carcass, small-biomass carcass, old carcass, non-carcass activity, and resting). We used multinomial logistic regression to predict the probability of clusters belonging to each class. Two cross-validation methods-leaving out individual clusters, or leaving out individual bears-showed that correct prediction of bear visitation to large-biomass carcasses was 78-88 %, whereas the false-positive rate was 18-24 %. As a case study, we applied our predictive model to a GPS data set of 266 bear-years in the Greater Yellowstone Ecosystem (2002-2011) and examined trends in carcass visitation during fall hyperphagia (September-October). We identified 1997 spatial GPS clusters, of which 347 were predicted to be large-biomass carcasses. We used the clustered data to develop a carcass visitation index, which varied annually, but more than doubled during the study period. Our study demonstrates the effectiveness and utility of identifying GPS clusters associated with carcass visitation by a facultative carnivore.

  13. Grizzly bears exhibit augmented insulin sensitivity while obese prior to a reversible insulin resistance during hibernation.

    Science.gov (United States)

    Nelson, O Lynne; Jansen, Heiko T; Galbreath, Elizabeth; Morgenstern, Kurt; Gehring, Jamie Lauren; Rigano, Kimberly Scott; Lee, Jae; Gong, Jianhua; Shaywitz, Adam J; Vella, Chantal A; Robbins, Charles T; Corbit, Kevin C

    2014-08-01

    The confluence of obesity and diabetes as a worldwide epidemic necessitates the discovery of new therapies. Success in this endeavor requires translatable preclinical studies, which traditionally employ rodent models. As an alternative approach, we explored hibernation where obesity is a natural adaptation to survive months of fasting. Here we report that grizzly bears exhibit seasonal tripartite insulin responsiveness such that obese animals augment insulin sensitivity but only weeks later enter hibernation-specific insulin resistance (IR) and subsequently reinitiate responsiveness upon awakening. Preparation for hibernation is characterized by adiposity coupled to increased insulin sensitivity via modified PTEN/AKT signaling specifically in adipose tissue, suggesting a state of "healthy" obesity analogous to humans with PTEN haploinsufficiency. Collectively, we show that bears reversibly cope with homeostatic perturbations considered detrimental to humans and describe a mechanism whereby IR functions not as a late-stage metabolic adaptation to obesity, but rather a gatekeeper of the fed-fasting transition.

  14. Detecting grizzly bear use of ungulate carcasses using global positioning system telemetry and activity data

    Science.gov (United States)

    Ebinger, Michael R.; Haroldson, Mark A.; van Manen, Frank T.; Costello, Cecily M; Bjornlie, Daniel D; Thompson, Daniel J.; Gunther, Kerry A.; Fortin, Jennifer K.; Teisberg, Justin E.; Pils, Shannon R; White, P J; Cain, Steven L; Cross, Paul C.

    2016-01-01

    Global positioning system (GPS) wildlife collars have revolutionized wildlife research. Studies of predation by free-ranging carnivores have particularly benefited from the application of location clustering algorithms to determine when and where predation events occur. These studies have changed our understanding of large carnivore behavior, but the gains have concentrated on obligate carnivores. Facultative carnivores, such as grizzly/brown bears (Ursus arctos), exhibit a variety of behaviors that can lead to the formation of GPS clusters. We combined clustering techniques with field site investigations of grizzly bear GPS locations (n = 732 site investigations; 2004–2011) to produce 174 GPS clusters where documented behavior was partitioned into five classes (large-biomass carcass, small-biomass carcass, old carcass, non-carcass activity, and resting). We used multinomial logistic regression to predict the probability of clusters belonging to each class. Two cross-validation methods—leaving out individual clusters, or leaving out individual bears—showed that correct prediction of bear visitation to large-biomass carcasses was 78–88%, whereas the false-positive rate was 18–24%. As a case study, we applied our predictive model to a GPS data set of 266 bear-years in the Greater Yellowstone Ecosystem (2002–2011) and examined trends in carcass visitation during fall hyperphagia (September–October). We identified 1997 spatial GPS clusters, of which 347 were predicted to be large-biomass carcasses. We used the clustered data to develop a carcass visitation index, which varied annually, but more than doubled during the study period. Our study demonstrates the effectiveness and utility of identifying GPS clusters associated with carcass visitation by a facultative carnivore.

  15. Multiple data sources improve DNA-based mark-recapture population estimates of grizzly bears.

    Science.gov (United States)

    Boulanger, John; Kendall, Katherine C; Stetz, Jeffrey B; Roon, David A; Waits, Lisette P; Paetkau, David

    2008-04-01

    A fundamental challenge to estimating population size with mark-recapture methods is heterogeneous capture probabilities and subsequent bias of population estimates. Confronting this problem usually requires substantial sampling effort that can be difficult to achieve for some species, such as carnivores. We developed a methodology that uses two data sources to deal with heterogeneity and applied this to DNA mark-recapture data from grizzly bears (Ursus arctos). We improved population estimates by incorporating additional DNA "captures" of grizzly bears obtained by collecting hair from unbaited bear rub trees concurrently with baited, grid-based, hair snag sampling. We consider a Lincoln-Petersen estimator with hair snag captures as the initial session and rub tree captures as the recapture session and develop an estimator in program MARK that treats hair snag and rub tree samples as successive sessions. Using empirical data from a large-scale project in the greater Glacier National Park, Montana, USA, area and simulation modeling we evaluate these methods and compare the results to hair-snag-only estimates. Empirical results indicate that, compared with hair-snag-only data, the joint hair-snag-rub-tree methods produce similar but more precise estimates if capture and recapture rates are reasonably high for both methods. Simulation results suggest that estimators are potentially affected by correlation of capture probabilities between sample types in the presence of heterogeneity. Overall, closed population Huggins-Pledger estimators showed the highest precision and were most robust to sparse data, heterogeneity, and capture probability correlation among sampling types. Results also indicate that these estimators can be used when a segment of the population has zero capture probability for one of the methods. We propose that this general methodology may be useful for other species in which mark-recapture data are available from multiple sources.

  16. Human perspectives and conservation of grizzly bears in Banff National Park, Canada.

    Science.gov (United States)

    Chamberlain, Emily C; Rutherford, Murray B; Gibeau, Michael L

    2012-06-01

    Some conservation initiatives provoke intense conflict among stakeholders. The need for action, the nature of the conservation measures, and the effects of these measures on human interests may be disputed. Tools are needed to depolarize such situations, foster understanding of the perspectives of people involved, and find common ground. We used Q methodology to explore stakeholders' perspectives on conservation and management of grizzly bears (Ursus arctos horribilis) in Banff National Park and the Bow River watershed of Alberta, Canada. Twenty-nine stakeholders participated in the study, including local residents, scientists, agency employees, and representatives of nongovernmental conservation organizations and other interest groups. Participants rank ordered a set of statements to express their opinions on the problems of grizzly bear management (I-IV) and a second set of statements on possible solutions to the problems (A-C). Factor analysis revealed that participants held 4 distinct views of the problems: individuals associated with factor I emphasized deficiencies in goals and plans; those associated with factor II believed that problems had been exaggerated; those associated with factor III blamed institutional flaws such as disjointed management and inadequate resources; and individuals associated with factor IV blamed politicized decision making. There were 3 distinct views about the best solutions to the problems: individuals associated with factor A called for increased conservation efforts; those associated with factor B wanted reforms in decision-making processes; and individuals associated with factor C supported active landscape management. We connected people's definitions of the problem with their preferred solutions to form 5 overall problem narratives espoused by groups in the study: the problem is deficient goals and plans, the solution is to prioritize conservation efforts (planning-oriented conservation advocates); the problem is flawed

  17. Geographic pattern of serum antibody prevalence for Brucella spp. in caribou, grizzly bears, and wolves from Alaska, 1975-1998.

    Science.gov (United States)

    Zarnke, Randall L; Ver Hoef, Jay M; DeLong, Robert A

    2006-07-01

    Blood samples were collected from 2,635 caribou (Rangifer tarandus), 1,238 grizzly bears (Ursus arctos), and 930 wolves (Canis lupus) from throughout mainland Alaska during 1975-98. Sera were tested for evidence of exposure to Brucella spp. Serum antibody prevalences were highest in the northwestern region of the state. In any specific area, antibody prevalences for caribou and wolves were of a similar magnitude, whereas antibody prevalence for bears in these same areas were two to three times higher.

  18. Effect of season and high ambient temperature on activity levels and patterns of grizzly bears (Ursus arctos.

    Directory of Open Access Journals (Sweden)

    Michelle L McLellan

    Full Text Available Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4-27.3°C and hot (27.9-40.1°C days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.

  19. Effect of season and high ambient temperature on activity levels and patterns of grizzly bears (Ursus arctos).

    Science.gov (United States)

    McLellan, Michelle L; McLellan, Bruce N

    2015-01-01

    Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos) increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C) and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4-27.3°C) and hot (27.9-40.1°C) days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.

  20. Cooperative Recovery Initiative (2016) Grizzly Bear Aware: Conflict Resolution and Habitat Restoration in the Centennial Valley and Southwest Montana Interim Report

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The project will take a three pronged approach to implement conservation actions that prevent or reduce Grizzly Bear human conflicts, enhance habitats and improve...

  1. Fast carnivores and slow herbivores: differential foraging strategies among grizzly bears in the Canadian Arctic.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E; Hobson, Keith A; Branigan, Marsha; Nagy, John A

    2011-04-01

    Categorizing animal populations by diet can mask important intrapopulation variation, which is crucial to understanding a species' trophic niche width. To test hypotheses related to intrapopulation variation in foraging or the presence of diet specialization, we conducted stable isotope analysis (δ(13)C, δ(15)N) on hair and claw samples from 51 grizzly bears (Ursus arctos) collected from 2003 to 2006 in the Mackenzie Delta region of the Canadian Arctic. We examined within-population differences in the foraging patterns of males and females and the relationship between trophic position (derived from δ(15)N measurements) and individual movement. The range of δ(15)N values in hair and claw (2.0-11.0‰) suggested a wide niche width and cluster analyses indicated the presence of three foraging groups within the population, ranging from near-complete herbivory to near-complete carnivory. We found no linear relationship between home range size and trophic position when the data were continuous or when grouped by foraging behavior. However, the movement rate of females increased linearly with trophic position. We used multisource dual-isotope mixing models to determine the relative contributions of seven prey sources within each foraging group for both males and females. The mean bear dietary endpoint across all foraging groups for each sex fell toward the center of the mixing polygon, which suggested relatively well-mixed diets. The primary dietary difference across foraging groups was the proportional contribution of herbaceous foods, which decreased for both males and females from 42-76 to 0-27% and 62-81 to 0-44%, respectively. Grizzlies of the Mackenzie Delta live in extremely harsh conditions and identifying within-population diet specialization has improved our understanding of varying habitat requirements within the population.

  2. Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

    Science.gov (United States)

    Levi, Taal; Darimont, Chris T; Macduffee, Misty; Mangel, Marc; Paquet, Paul; Wilmers, Christopher C

    2012-01-01

    Implementation of ecosystem-based fisheries management (EBFM) requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC), Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem) equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a generalizable method

  3. Using grizzly bears to assess harvest-ecosystem tradeoffs in salmon fisheries.

    Directory of Open Access Journals (Sweden)

    Taal Levi

    Full Text Available Implementation of ecosystem-based fisheries management (EBFM requires a clear conceptual and quantitative framework for assessing how different harvest options can modify benefits to ecosystem and human beneficiaries. We address this social-ecological need for Pacific salmon fisheries, which are economically valuable but intercept much of the annual pulse of nutrient subsidies that salmon provide to terrestrial and aquatic food webs. We used grizzly bears, vectors of salmon nutrients and animals with densities strongly coupled to salmon abundance, as surrogates for "salmon ecosystem" function. Combining salmon biomass and stock-recruitment data with stable isotope analysis, we assess potential tradeoffs between fishery yields and bear population densities for six sockeye salmon stocks in Bristol Bay, Alaska, and British Columbia (BC, Canada. For the coastal stocks, we find that both bear densities and fishery yields would increase substantially if ecosystem allocations of salmon increase from currently applied lower to upper goals and beyond. This aligning of benefits comes at a potential cost, however, with the possibility of forgoing harvests in low productivity years. In contrast, we detect acute tradeoffs between bear densities and fishery yields in interior stocks within the Fraser River, BC, where biomass from other salmon species is low. There, increasing salmon allocations to ecosystems would benefit threatened bear populations at the cost of reduced long-term yields. To resolve this conflict, we propose an EBFM goal that values fisheries and bears (and by extension, the ecosystem equally. At such targets, ecosystem benefits are unexpectedly large compared with losses in fishery yields. To explore other management options, we generate tradeoff curves that provide stock-specific accounting of the expected loss to fishers and gain to bears as more salmon escape the fishery. Our approach, modified to suit multiple scenarios, provides a

  4. Influence of whitebark pine decline on fall habitat use and movements of grizzly bears in the Greater Yellowstone Ecosystem.

    Science.gov (United States)

    Costello, Cecily M; van Manen, Frank T; Haroldson, Mark A; Ebinger, Michael R; Cain, Steven L; Gunther, Kerry A; Bjornlie, Daniel D

    2014-05-01

    When abundant, seeds of the high-elevation whitebark pine (WBP; Pinus albicaulis) are an important fall food for grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem. Rates of bear mortality and bear/human conflicts have been inversely associated with WBP productivity. Recently, mountain pine beetles (Dendroctonus ponderosae) have killed many cone-producing WBP trees. We used fall (15 August-30 September) Global Positioning System locations from 89 bear years to investigate temporal changes in habitat use and movements during 2000-2011. We calculated Manly-Chesson (MC) indices for selectivity of WBP habitat and secure habitat (≥500 m from roads and human developments), determined dates of WBP use, and documented net daily movement distances and activity radii. To evaluate temporal trends, we used regression, model selection, and candidate model sets consisting of annual WBP production, sex, and year. One-third of sampled grizzly bears had fall ranges with little or no mapped WBP habitat. Most other bears (72%) had a MC index above 0.5, indicating selection for WBP habitats. From 2000 to 2011, mean MC index decreased and median date of WBP use shifted about 1 week later. We detected no trends in movement indices over time. Outside of national parks, there was no correlation between the MC indices for WBP habitat and secure habitat, and most bears (78%) selected for secure habitat. Nonetheless, mean MC index for secure habitat decreased over the study period during years of good WBP productivity. The wide diet breadth and foraging plasticity of grizzly bears likely allowed them to adjust to declining WBP. Bears reduced use of WBP stands without increasing movement rates, suggesting they obtained alternative fall foods within their local surroundings. However, the reduction in mortality risk historically associated with use of secure, high-elevation WBP habitat may be diminishing for bears residing in multiple-use areas.

  5. Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone

    Science.gov (United States)

    Middleton, Arthur D.; Morrison, Thomas A.; Fortin, Jennifer K.; Robbins, Charles T.; Proffitt, Kelly M.; White, P.J.; McWhirter, Douglas E.; Koel, Todd M.; Brimeyer, Douglas G.; Fairbanks, W. Sue; Kauffman, Matthew J.

    2013-01-01

    The loss of aquatic subsidies such as spawning salmonids is known to threaten a number of terrestrial predators, but the effects on alternative prey species are poorly understood. At the heart of the Greater Yellowstone ecosystem, an invasion of lake trout has driven a dramatic decline of native cutthroat trout that migrate up the shallow tributaries of Yellowstone Lake to spawn each spring. We explore whether this decline has amplified the effect of a generalist consumer, the grizzly bear, on populations of migratory elk that summer inside Yellowstone National Park (YNP). Recent studies of bear diets and elk populations indicate that the decline in cutthroat trout has contributed to increased predation by grizzly bears on the calves of migratory elk. Additionally, a demographic model that incorporates the increase in predation suggests that the magnitude of this diet shift has been sufficient to reduce elk calf recruitment (4–16%) and population growth (2–11%). The disruption of this aquatic–terrestrial linkage could permanently alter native species interactions in YNP. Although many recent ecological changes in YNP have been attributed to the recovery of large carnivores—particularly wolves—our work highlights a growing role of human impacts on the foraging behaviour of grizzly bears.

  6. Grizzly bear predation links the loss of native trout to the demography of migratory elk in Yellowstone.

    Science.gov (United States)

    Middleton, Arthur D; Morrison, Thomas A; Fortin, Jennifer K; Robbins, Charles T; Proffitt, Kelly M; White, P J; McWhirter, Douglas E; Koel, Todd M; Brimeyer, Douglas G; Fairbanks, W Sue; Kauffman, Matthew J

    2013-07-07

    The loss of aquatic subsidies such as spawning salmonids is known to threaten a number of terrestrial predators, but the effects on alternative prey species are poorly understood. At the heart of the Greater Yellowstone ecosystem, an invasion of lake trout has driven a dramatic decline of native cutthroat trout that migrate up the shallow tributaries of Yellowstone Lake to spawn each spring. We explore whether this decline has amplified the effect of a generalist consumer, the grizzly bear, on populations of migratory elk that summer inside Yellowstone National Park (YNP). Recent studies of bear diets and elk populations indicate that the decline in cutthroat trout has contributed to increased predation by grizzly bears on the calves of migratory elk. Additionally, a demographic model that incorporates the increase in predation suggests that the magnitude of this diet shift has been sufficient to reduce elk calf recruitment (4-16%) and population growth (2-11%). The disruption of this aquatic-terrestrial linkage could permanently alter native species interactions in YNP. Although many recent ecological changes in YNP have been attributed to the recovery of large carnivores--particularly wolves--our work highlights a growing role of human impacts on the foraging behaviour of grizzly bears.

  7. Evaluation of rules to distinguish unique female grizzly bears with cubs in Yellowstone

    Science.gov (United States)

    Schwartz, C.C.; Haroldson, M.A.; Cherry, S.; Keating, K.A.

    2008-01-01

    The United States Fish and Wildlife Service uses counts of unduplicated female grizzly bears (Ursus arctos) with cubs-of-the-year to establish limits of sustainable mortality in the Greater Yellowstone Ecosystem, USA. Sightings are dustered into observations of unique bears based on an empirically derived rule set. The method has never been tested or verified. To evaluate the rule set, we used data from radiocollared females obtained during 1975-2004 to simulate populations under varying densities, distributions, and sighting frequencies. We tested individual rules and rule-set performance, using custom software to apply the rule-set and duster sightings. Results indicated most rules were violated to some degree, and rule-based dustering consistently underestimated the minimum number of females and total population size derived from a nonparametric estimator (Chao2). We conclude that the current rule set returns conservative estimates, but with minor improvements, counts of unduplicated females-with-cubs can serve as a reasonable index of population size useful for establishing annual mortality limits. For the Yellowstone population, the index is more practical and cost-effective than capture-mark-recapture using either DNA hair snagging or aerial surveys with radiomarked bears. The method has useful application in other ecosystems, but we recommend rules used to distinguish unique females be adapted to local conditions and tested.

  8. Diet and environment shape fecal bacterial microbiota composition and enteric pathogen load of grizzly bears.

    Directory of Open Access Journals (Sweden)

    Clarissa Schwab

    Full Text Available BACKGROUND: Diet and environment impact the composition of mammalian intestinal microbiota; dietary or health disturbances trigger alterations in intestinal microbiota composition and render the host susceptible to enteric pathogens. To date no long term monitoring data exist on the fecal microbiota and pathogen load of carnivores either in natural environments or in captivity. This study investigates fecal microbiota composition and the presence of pathogenic Escherichia coli and toxigenic clostridia in wild and captive grizzly bears (Ursus arctos and relates these to food resources consumed by bears. METHODOLOGY/PRINCIPAL FINDINGS: Feces were obtained from animals of two wild populations and from two captive animals during an active bear season. Wild animals consumed a diverse diet composed of plant material, animal prey and insects. Captive animals were fed a regular granulated diet with a supplement of fruits and vegetables. Bacterial populations were analyzed using quantitative PCR. Fecal microbiota composition fluctuated in wild and in captive animals. The abundance of Clostridium clusters I and XI, and of C. perfringens correlated to regular diet protein intake. Enteroaggregative E. coli were consistently present in all populations. The C. sordellii phospholipase C was identified in three samples of wild animals and for the first time in Ursids. CONCLUSION: This is the first longitudinal study monitoring the fecal microbiota of wild carnivores and comparing it to that of captive individuals of the same species. Location and diet affected fecal bacterial populations as well as the presence of enteric pathogens.

  9. The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears.

    Science.gov (United States)

    Mowat, Garth; Curtis, P Jeff; Lafferty, Diana J R

    2017-01-01

    Stable isotope ratios of grizzly bear (Ursus arctos) guard hair collected from bears on the lower Stikine River, British Columbia (BC) were analyzed to: 1) test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp.) diet fraction estimate relative to δ15N as is conventionally done, 2) investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces), marmot (Marmota caligata), and mountain goat (Oreamnos americanus) and, 3) examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when bears were

  10. Re-evaluation of Yellowstone grizzly bear population dynamics not supported by empirical data: response to Doak & Cutler

    Science.gov (United States)

    van Manen, Frank T.; Ebinger, Michael R.; Haroldson, Mark A.; Harris, Richard B.; Higgs, Megan D.; Cherry, Steve; White, Gary C.; Schwartz, Charles C.

    2014-01-01

    Doak and Cutler critiqued methods used by the Interagency Grizzly Bear Study Team (IGBST) to estimate grizzly bear population size and trend in the Greater Yellowstone Ecosystem. Here, we focus on the premise, implementation, and interpretation of simulations they used to support their arguments. They argued that population increases documented by IGBST based on females with cubs-of-the-year were an artifact of increased search effort. However, we demonstrate their simulations were neither reflective of the true observation process nor did their results provide statistical support for their conclusion. They further argued that survival and reproductive senescence should be incorporated into population projections, but we demonstrate their choice of extreme mortality risk beyond age 20 and incompatible baseline fecundity led to erroneous conclusions. The conclusions of Doak and Cutler are unsubstantiated when placed within the context of a thorough understanding of the data, study system, and previous research findings and publications.

  11. Despotism and risk of infanticide influence grizzly bear den-site selection.

    Directory of Open Access Journals (Sweden)

    Nathan S Libal

    Full Text Available Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142, adult male (n = 36, and juvenile (n = 35 den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC = 0.926 and elevation as the best predictive variable for adult male (AUC = 0.880 den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841 den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52 and steeper slopes (mean = 21.9°, SE = 1.1 than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9 den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.

  12. Despotism and risk of infanticide influence grizzly bear den-site selection.

    Science.gov (United States)

    Libal, Nathan S; Belant, Jerrold L; Leopold, Bruce D; Wang, Guiming; Owen, Patricia A

    2011-01-01

    Given documented social dominance and intraspecific predation in bear populations, the ideal despotic distribution model and sex hypothesis of sexual segregation predict adult female grizzly bears (Ursus arctos) will avoid areas occupied by adult males to reduce risk of infanticide. Under ideal despotic distribution, juveniles should similarly avoid adult males to reduce predation risk. Den-site selection and use is an important component of grizzly bear ecology and may be influenced by multiple factors, including risk from conspecifics. To test the role of predation risk and the sex hypothesis of sexual segregation, we compared adult female (n = 142), adult male (n = 36), and juvenile (n = 35) den locations in Denali National Park and Preserve, Alaska, USA. We measured elevation, aspect, slope, and dominant land cover for each den site, and used maximum entropy modeling to determine which variables best predicted den sites. We identified the global model as the best-fitting model for adult female (area under curve (AUC) = 0.926) and elevation as the best predictive variable for adult male (AUC = 0.880) den sites. The model containing land cover and elevation best-predicted juvenile (AUC = 0.841) den sites. Adult females spatially segregated from adult males, with dens characterized by higher elevations (mean= 1,412 m, SE = 52) and steeper slopes (mean = 21.9°, SE = 1.1) than adult male (elevation: mean = 1,209 m, SE = 76; slope: mean = 15.6°, SE = 1.9) den sites. Juveniles used a broad range of landscape attributes but did not avoid adult male denning areas. Observed spatial segregation by adult females supports the sex hypothesis of sexual segregation and we suggest is a mechanism to reduce risk of infanticide. Den site selection of adult males is likely related to distribution of food resources during spring.

  13. Prioritizing Sites for Protection and Restoration for Grizzly Bears (Ursus arctos) in Southwestern Alberta, Canada.

    Science.gov (United States)

    Braid, Andrew C R; Nielsen, Scott E

    2015-01-01

    As the influence of human activities on natural systems continues to expand, there is a growing need to prioritize not only pristine sites for protection, but also degraded sites for restoration. We present an approach for simultaneously prioritizing sites for protection and restoration that considers landscape patterns for a threatened population of grizzly bears (Ursus arctos) in southwestern Alberta, Canada. We considered tradeoffs between bottom-up (food resource supply) and top-down (mortality risk from roads) factors affecting seasonal habitat quality for bears. Simulated annealing was used to prioritize source-like sites (high habitat productivity, low mortality risk) for protection, as well as sink-like sites (high habitat productivity, high mortality risk) for restoration. Priority source-like habitats identified key conservation areas where future developments should be limited, whereas priority sink-like habitats identified key areas for mitigating road-related mortality risk with access management. Systematic conservation planning methods can be used to complement traditional habitat-based methods for individual focal species by identifying habitats where conservation actions (both protection and restoration) have the highest potential utility.

  14. Prioritizing Sites for Protection and Restoration for Grizzly Bears (Ursus arctos in Southwestern Alberta, Canada.

    Directory of Open Access Journals (Sweden)

    Andrew C R Braid

    Full Text Available As the influence of human activities on natural systems continues to expand, there is a growing need to prioritize not only pristine sites for protection, but also degraded sites for restoration. We present an approach for simultaneously prioritizing sites for protection and restoration that considers landscape patterns for a threatened population of grizzly bears (Ursus arctos in southwestern Alberta, Canada. We considered tradeoffs between bottom-up (food resource supply and top-down (mortality risk from roads factors affecting seasonal habitat quality for bears. Simulated annealing was used to prioritize source-like sites (high habitat productivity, low mortality risk for protection, as well as sink-like sites (high habitat productivity, high mortality risk for restoration. Priority source-like habitats identified key conservation areas where future developments should be limited, whereas priority sink-like habitats identified key areas for mitigating road-related mortality risk with access management. Systematic conservation planning methods can be used to complement traditional habitat-based methods for individual focal species by identifying habitats where conservation actions (both protection and restoration have the highest potential utility.

  15. Estimating total human-caused mortality from reported mortality using data from radio-instrumented grizzly bears

    Science.gov (United States)

    Cherry, S.; Haroldson, M.A.; Robison-Cox, J.; Schwartz, C.C.

    2002-01-01

    Tracking mortality of the Yellowstone grizzly bear (Ursus arctos horribilis) is an essential issue of the recovery process. Problem bears removed by agencies are well documented. Deaths of radiocollared bears are known or, in many cases, can be reliably inferred. Additionally, the public reports an unknown proportion of deaths of uncollared bears. Estimating the number of non-agency human-caused mortalities is a necessary element that must be factored into the total annual mortality. Here, we describe a method of estimating the number of such deaths from records of reported human-caused bear mortalities. We used a hierarchical Bayesian model with a non-informative prior distribution for the number of deaths. Estimates of reporting rates developed from deaths of radio-instrumented bears from 1983 to 2000 were used to develop beta prior probability distributions that the public will report a death. Twenty-seven known deaths of radio-instrumented bears occurred during this period with 16 reported. Additionally, fates of 23 radio-instrumented bears were unknown and are considered possible unreported mortalities. We describe 3 ways of using this information to specify prior distributions on the probability a death will be reported by the public. We estimated total deaths of noninstrumented bears in running 3-year periods from 1993 to 2000. Thirty-nine known deaths of non-instrumented bears were reported during this period, ranging from 0 to 7/year. Seven possible mortalities were recorded. We applied the method to both sets of mortality data. Results from this method can be combined with agency removals and deaths of collared bears to produce defensible estimates of total mortality over relevant periods and to incorporate uncertainty when evaluating mortality limits established for the Yellowstone grizzly bear population. Assumptions and limitations of this procedure are discussed.

  16. Estimating numbers of females with cubs-of-the-year in the Yellowstone grizzly bear population

    Science.gov (United States)

    Keating, K.A.; Schwartz, C.C.; Haroldson, M.A.; Moody, D.

    2001-01-01

    For grizzly bears (Ursus arctos horribilis) in the Greater Yellowstone Ecosystem (GYE), minimum population size and allowable numbers of human-caused mortalities have been calculated as a function of the number of unique females with cubs-of-the-year (FCUB) seen during a 3- year period. This approach underestimates the total number of FCUB, thereby biasing estimates of population size and sustainable mortality. Also, it does not permit calculation of valid confidence bounds. Many statistical methods can resolve or mitigate these problems, but there is no universal best method. Instead, relative performances of different methods can vary with population size, sample size, and degree of heterogeneity among sighting probabilities for individual animals. We compared 7 nonparametric estimators, using Monte Carlo techniques to assess performances over the range of sampling conditions deemed plausible for the Yellowstone population. Our goal was to estimate the number of FCUB present in the population each year. Our evaluation differed from previous comparisons of such estimators by including sample coverage methods and by treating individual sightings, rather than sample periods, as the sample unit. Consequently, our conclusions also differ from earlier studies. Recommendations regarding estimators and necessary sample sizes are presented, together with estimates of annual numbers of FCUB in the Yellowstone population with bootstrap confidence bounds.

  17. Testing landscape modeling approaches for environmental impact assessment of mining land use on grizzly bears (Ursus arctos horribilis) in the foothills region of west central Alberta

    Energy Technology Data Exchange (ETDEWEB)

    Symbaluk, M.D. [Elk Valley Coal Corp., Hinton, AB (Canada). Cardinal River Operations

    2008-07-01

    The Cheviot open pit coal mine is located on the front range of the Rocky Mountains in Alberta. The environmental impact assessment (EIA) requirements for the mining project included an assessment of the cumulative effects of past, existing, and immanent activities on a 3040 km{sup 2} study area radiating approximately 25 km around the proposed project area. The grizzly bear was identified as a flagship valued ecosystem component (VEC) for assessing the regional cumulative effects of the proposed Cheviot project. In this portion of the study, a grizzly bear habitat effectiveness model was used to monitor grizzly bear response to mining land use in the study area. An investigation of grizzly bear movement paths prior to and during mine disturbances demonstrated that mining land use does not present significant barriers to grizzly bear activities. The study demonstrated the importance of using inductive modelling tools at appropriate scales, as well as the use of site-specific empirical data. It was concluded that continued monitoring of mining sites is needed to ensure that adaptive management processes are improved. A review of the Cheviot cumulative environmental effects (CEA) process was also provided. 17 refs., 1 fig.

  18. Morphological variability and molecular identification of Uncinaria spp. (Nematoda: Ancylostomatidae) from grizzly and black bears: new species or phenotypic plasticity?

    Science.gov (United States)

    Catalano, Stefano; Lejeune, Manigandan; van Paridon, Bradley; Pagan, Christopher A; Wasmuth, James D; Tizzani, Paolo; Duignan, Pádraig J; Nadler, Steven A

    2015-04-01

    The hookworms Uncinaria rauschi Olsen, 1968 and Uncinaria yukonensis ( Wolfgang, 1956 ) were formally described from grizzly ( Ursus arctos horribilis) and black bears ( Ursus americanus ) of North America. We analyzed the intestinal tracts of 4 grizzly and 9 black bears from Alberta and British Columbia, Canada and isolated Uncinaria specimens with anatomical traits never previously documented. We applied morphological and molecular techniques to investigate the taxonomy and phylogeny of these Uncinaria parasites. The morphological analysis supported polymorphism at the vulvar region for females of both U. rauschi and U. yukonensis. The hypothesis of morphological plasticity for U. rauschi and U. yukonensis was confirmed by genetic analysis of the internal transcribed spacers (ITS-1 and ITS-2) of the nuclear ribosomal DNA. Two distinct genotypes were identified, differing at 5 fixed sites for ITS-1 (432 base pairs [bp]) and 7 for ITS-2 (274 bp). Morphometric data for U. rauschi revealed host-related size differences: adult U. rauschi were significantly larger in black bears than in grizzly bears. Interpretation of these results, considering the historical biogeography of North American bears, suggests a relatively recent host-switching event of U. rauschi from black bears to grizzly bears which likely occurred after the end of the Wisconsin glaciation. Phylogenetic maximum parsimony (MP) and maximum likelihood (ML) analyses of the concatenated ITS-1 and ITS-2 datasets strongly supported monophyly of U. rauschi and U. yukonensis and their close relationship with Uncinaria stenocephala (Railliet, 1884), the latter a parasite primarily of canids and felids. Relationships among species within this group, although resolved by ML, were unsupported by MP and bootstrap resampling. The clade of U. rauschi, U. yukonensis, and U. stenocephala was recovered as sister to the clade represented by Uncinaria spp. from otariid pinnipeds. These results support the absence of strict

  19. Development and application of an antibody-based protein microarray to assess physiological stress in grizzly bears (Ursus arctos).

    Science.gov (United States)

    Carlson, Ruth I; Cattet, Marc R L; Sarauer, Bryan L; Nielsen, Scott E; Boulanger, John; Stenhouse, Gordon B; Janz, David M

    2016-01-01

    A novel antibody-based protein microarray was developed that simultaneously determines expression of 31 stress-associated proteins in skin samples collected from free-ranging grizzly bears (Ursus arctos) in Alberta, Canada. The microarray determines proteins belonging to four broad functional categories associated with stress physiology: hypothalamic-pituitary-adrenal axis proteins, apoptosis/cell cycle proteins, cellular stress/proteotoxicity proteins and oxidative stress/inflammation proteins. Small skin samples (50-100 mg) were collected from captured bears using biopsy punches. Proteins were isolated and labelled with fluorescent dyes, with labelled protein homogenates loaded onto microarrays to hybridize with antibodies. Relative protein expression was determined by comparison with a pooled standard skin sample. The assay was sensitive, requiring 80 µg of protein per sample to be run in triplicate on the microarray. Intra-array and inter-array coefficients of variation for individual proteins were generally bears. This suggests that remotely delivered biopsy darts could be used in future sampling. Using generalized linear mixed models, certain proteins within each functional category demonstrated altered expression with respect to differences in year, season, geographical sampling location within Alberta and bear biological parameters, suggesting that these general variables may influence expression of specific proteins in the microarray. Our goal is to apply the protein microarray as a conservation physiology tool that can detect, evaluate and monitor physiological stress in grizzly bears and other species at risk over time in response to environmental change.

  20. 75 FR 63434 - Kootenai National Forest, Lincoln County, Montana; Grizzly Vegetation and Transportation...

    Science.gov (United States)

    2010-10-15

    ... on the threatened Cabinet-Yaak grizzly bears which inhabit the area. Regarding the Grizzly Vegetation... Situation 1 lands which require the agency to ``favor the needs of the grizzly bear when grizzly habitat and... the grizzly bear analysis. DATES: Under 40 CFR 1502.9(c)(4), there is no formal scoping period...

  1. Changing numbers of spawning cutthroat trout in tributary streams of Yellowstone Lake and estimates of grizzly bears visiting streams from DNA

    Science.gov (United States)

    Haroldson, M.A.; Gunther, K.A.; Reinhart, D.P.; Podruzny, S.R.; Cegelski, C.; Waits, L.; Wyman, T.C.; Smith, J.

    2005-01-01

    Spawning Yellowstone cutthroat trout (Oncorhynchus clarki) provide a source of highly digestible energy for grizzly bears (Ursus arctos) that visit tributary streams to Yellowstone Lake during the spring and early summer. During 1985–87, research documented grizzly bears fishing on 61% of the 124 tributary streams to the lake. Using track measurements, it was estimated that a minimum of 44 grizzly bears fished those streams annually. During 1994, non-native lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake. Lake trout are efficient predators and have the potential to reduce the native cutthroat population and negatively impact terrestrial predators that use cutthroat trout as a food resource. In 1997, we began sampling a subset of streams (n = 25) from areas of Yellowstone Lake surveyed during the previous study to determine if changes in spawner numbers or bear use had occurred. Comparisons of peak numbers and duration suggested a considerable decline between study periods in streams in the West Thumb area of the lake. The apparent decline may be due to predation by lake trout. Indices of bear use also declined on West Thumb area streams. We used DNA from hair collected near spawning streams to estimate the minimum number of bears visiting the vicinity of spawning streams. Seventy-four individual bears were identified from 429 hair samples. The annual number of individuals detected ranged from 15 in 1997 to 33 in 2000. Seventy percent of genotypes identified were represented by more than 1 sample, but only 31% of bears were documented more than 1 year of the study. Sixty-two (84%) bears were only documented in 1 segment of the lake, whereas 12 (16%) were found in 2–3 lake segments. Twenty-seven bears were identified from hair collected at multiple streams. One bear was identified on 6 streams in 2 segments of the lake and during 3 years of the study. We used encounter histories derived from DNA and the Jolly-Seber procedure in Program MARK

  2. Multiple estimates of effective population size for monitoring a long-lived vertebrate: An application to Yellowstone grizzly bears

    Science.gov (United States)

    Kamath, Pauline L.; Haroldson, Mark A.; Luikart, Gordon; Paetkau, David; Whitman, Craig L.; van Manen, Frank T.

    2015-01-01

    Effective population size (Ne) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem provides a rare opportunity to examine the usefulness of different Ne estimators for monitoring. We genotyped 729 Yellowstone grizzly bears using 20 microsatellites and applied three single-sample estimators to examine contemporary trends in generation interval (GI), effective number of breeders (Nb) and Ne during 1982–2007. We also used multisample methods to estimate variance (NeV) and inbreeding Ne (NeI). Single-sample estimates revealed positive trajectories, with over a fourfold increase in Ne (≈100 to 450) and near doubling of the GI (≈8 to 14) from the 1980s to 2000s. NeV (240–319) and NeI (256) were comparable with the harmonic mean single-sample Ne (213) over the time period. Reanalysing historical data, we found NeV increased from ≈80 in the 1910s–1960s to ≈280 in the contemporary population. The estimated ratio of effective to total census size (Ne/Nc) was stable and high (0.42–0.66) compared to previous brown bear studies. These results support independent demographic evidence for Yellowstone grizzly bear population growth since the 1980s. They further demonstrate how genetic monitoring of Ne can complement demographic-based monitoring of Nc and vital rates, providing a valuable tool for wildlife managers.

  3. Multiple estimates of effective population size for monitoring a long-lived vertebrate: an application to Yellowstone grizzly bears.

    Science.gov (United States)

    Kamath, Pauline L; Haroldson, Mark A; Luikart, Gordon; Paetkau, David; Whitman, Craig; van Manen, Frank T

    2015-11-01

    Effective population size (N(e)) is a key parameter for monitoring the genetic health of threatened populations because it reflects a population's evolutionary potential and risk of extinction due to genetic stochasticity. However, its application to wildlife monitoring has been limited because it is difficult to measure in natural populations. The isolated and well-studied population of grizzly bears (Ursus arctos) in the Greater Yellowstone Ecosystem provides a rare opportunity to examine the usefulness of different N(e) estimators for monitoring. We genotyped 729 Yellowstone grizzly bears using 20 microsatellites and applied three single-sample estimators to examine contemporary trends in generation interval (GI), effective number of breeders (N(b)) and N(e) during 1982-2007. We also used multisample methods to estimate variance (N(eV)) and inbreeding N(e) (N(eI)). Single-sample estimates revealed positive trajectories, with over a fourfold increase in N(e) (≈100 to 450) and near doubling of the GI (≈8 to 14) from the 1980s to 2000s. N(eV) (240-319) and N(eI) (256) were comparable with the harmonic mean single-sample N(e) (213) over the time period. Reanalysing historical data, we found N(eV) increased from ≈80 in the 1910s-1960s to ≈280 in the contemporary population. The estimated ratio of effective to total census size (N(e) /N(c)) was stable and high (0.42-0.66) compared to previous brown bear studies. These results support independent demographic evidence for Yellowstone grizzly bear population growth since the 1980s. They further demonstrate how genetic monitoring of N(e) can complement demographic-based monitoring of N(c) and vital rates, providing a valuable tool for wildlife managers.

  4. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  5. First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America.

    Science.gov (United States)

    Catalano, Stefano; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Pádraig J

    2014-04-01

    The cestode Taenia arctos was found at necropsy in the small intestine of a grizzly (Ursus arctos horribilis) and a black bear (Ursus americanus) from Kananaskis Country in southwestern Alberta, Canada. The autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit 1 gene confirmed their identity as T. arctos. This is the first report of T. arctos from definitive hosts in North America. Its detection in Canadian grizzly and black bears further supports the Holarctic distribution of this tapeworm species and its specificity for ursids as final hosts. Previously, T. arctos was unambiguously described at its adult stage in brown bears (Ursus arctos arctos) from Finland, and as larval stages in Eurasian elk (Alces alces) from Finland and moose (Alces americanus) from Alaska, USA. Given the morphological similarity between T. arctos and other Taenia species, the present study underlines the potential for misidentification of tapeworm taxa in previous parasitological reports from bears and moose across North America. The biogeographical history of both definitive and intermediate hosts in the Holarctic suggests an ancient interaction between U. arctos, Alces spp., and T. arctos, and a relatively recent host-switching event in U. americanus.

  6. Natural landscape features, human-related attractants, and conflict hotspots: A spatial analysis of human-grizzly bear conflicts

    Science.gov (United States)

    Wilson, S.M.; Madel, M.J.; Mattson, D.J.; Graham, J.M.; Burchfield, J.A.; Belsky, J.M.

    2005-01-01

    There is a long history of conflict in the western United States between humans and grizzly bears (Ursus arctos) involving agricultural attractants. However, little is known about the spatial dimensions of this conflict and the relative importance of different attractants. This study was undertaken to better understand the spatial and functional components of conflict between humans and grizzly bears on privately owned agricultural lands in Montana. Our investigations focused on spatial associations of rivers and creeks, livestock pastures, boneyards (livestock carcass dump sites), beehives, and grizzly bear habitat with reported human-grizzly bear conflicts during 1986-2001. We based our analysis on a survey of 61 of 64 livestock producers in our study in the Rocky Mountain East Front, Montana. With the assistance of livestock and honey producers, we mapped the locations of cattle and sheep pastures, boneyards, and beehives. We used density surface mapping to identify seasonal clusters of conflicts that we term conflict hotspots. Hotspots accounted for 75% of all conflicts and encompassed approximately 8% of the study area. We also differentiated chronic (4 or more years of conflicts) from non-chronic hotspots (fewer than 4 years of conflict). The 10 chronic hotpots accounted for 58% of all conflicts. Based on Monte Carlo simulations, we found that conflict locations were most strongly associated with rivers and creeks followed by sheep lambing areas and fall sheep pastures. Conflicts also were associated with cattle calving areas, spring cow-calf pastures, summer and fall cattle pastures, and boneyards. The Monte Carlo simulations indicated associations between conflict locations and unprotected beehives at specific analysis scales. Protected (fenced) beehives were less likely to experience conflicts than unprotected beehives. Conflicts occurred at a greater rate in riparian and wetland vegetation than would be expected. The majority of conflicts occurred in a

  7. Staying cool in a changing landscape: the influence of maximum daily ambient temperature on grizzly bear habitat selection.

    Science.gov (United States)

    Pigeon, Karine E; Cardinal, Etienne; Stenhouse, Gordon B; Côté, Steeve D

    2016-08-01

    To fulfill their needs, animals are constantly making trade-offs among limiting factors. Although there is growing evidence about the impact of ambient temperature on habitat selection in mammals, the role of environmental conditions and thermoregulation on apex predators is poorly understood. Our objective was to investigate the influence of ambient temperature on habitat selection patterns of grizzly bears in the managed landscape of Alberta, Canada. Grizzly bear habitat selection followed a daily and seasonal pattern that was influenced by ambient temperature, with adult males showing stronger responses than females to warm temperatures. Cutblocks aged 0-20 years provided an abundance of forage but were on average 6 °C warmer than mature conifer stands and 21- to 40-year-old cutblocks. When ambient temperatures increased, the relative change (odds ratio) in the probability of selection for 0- to 20-year-old cutblocks decreased during the hottest part of the day and increased during cooler periods, especially for males. Concurrently, the probability of selection for 21- to 40-year-old cutblocks increased on warmer days. Following plant phenology, the odds of selecting 0- to 20-year-old cutblocks also increased from early to late summer while the odds of selecting 21- to 40-year-old cutblocks decreased. Our results demonstrate that ambient temperatures, and therefore thermal requirements, play a significant role in habitat selection patterns and behaviour of grizzly bears. In a changing climate, large mammals may increasingly need to adjust spatial and temporal selection patterns in response to thermal constraints.

  8. Spatial analysis of factors influencing long-term stress in the grizzly bear (Ursus arctos population of Alberta, Canada.

    Directory of Open Access Journals (Sweden)

    Mathieu L Bourbonnais

    Full Text Available Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC generated from a threatened grizzly bear (Ursus arctos population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions inside and outside of parks and protected areas to account for substantial differences in anthropogenic activity and disturbance within the study area. Variance explained in the random forest models ranged from 55.34% to 74.96% for males and 58.15% to 68.46% for females. Predicted HCC levels were higher for females compared to males. Generally, high spatially continuous female HCC levels were associated with parks and protected areas while low-to-moderate levels were associated with increased anthropogenic disturbance. In contrast, male HCC levels were low in parks and protected areas and low-to-moderate in areas with increased anthropogenic disturbance. Spatial variability in gender-specific HCC levels reveal that the type and intensity of external stressors are not uniform across the landscape and that male and female grizzly bears may be exposed to, or perceive, potential stressors differently. We suggest observed spatial patterns of long-term stress may be the result of the availability and distribution of foods related to disturbance features, potential sexual segregation in available habitat selection, and may not be influenced by sources of mortality which represent acute traumas. In this wildlife

  9. Spatial analysis of factors influencing long-term stress in the grizzly bear (Ursus arctos) population of Alberta, Canada.

    Science.gov (United States)

    Bourbonnais, Mathieu L; Nelson, Trisalyn A; Cattet, Marc R L; Darimont, Chris T; Stenhouse, Gordon B

    2013-01-01

    Non-invasive measures for assessing long-term stress in free ranging mammals are an increasingly important approach for understanding physiological responses to landscape conditions. Using a spatially and temporally expansive dataset of hair cortisol concentrations (HCC) generated from a threatened grizzly bear (Ursus arctos) population in Alberta, Canada, we quantified how variables representing habitat conditions and anthropogenic disturbance impact long-term stress in grizzly bears. We characterized spatial variability in male and female HCC point data using kernel density estimation and quantified variable influence on spatial patterns of male and female HCC stress surfaces using random forests. Separate models were developed for regions inside and outside of parks and protected areas to account for substantial differences in anthropogenic activity and disturbance within the study area. Variance explained in the random forest models ranged from 55.34% to 74.96% for males and 58.15% to 68.46% for females. Predicted HCC levels were higher for females compared to males. Generally, high spatially continuous female HCC levels were associated with parks and protected areas while low-to-moderate levels were associated with increased anthropogenic disturbance. In contrast, male HCC levels were low in parks and protected areas and low-to-moderate in areas with increased anthropogenic disturbance. Spatial variability in gender-specific HCC levels reveal that the type and intensity of external stressors are not uniform across the landscape and that male and female grizzly bears may be exposed to, or perceive, potential stressors differently. We suggest observed spatial patterns of long-term stress may be the result of the availability and distribution of foods related to disturbance features, potential sexual segregation in available habitat selection, and may not be influenced by sources of mortality which represent acute traumas. In this wildlife system and others

  10. A Comparison of Grizzly Bear Demographic Parameters Estimated from Non-Spatial and Spatial Open Population Capture-Recapture Models.

    Directory of Open Access Journals (Sweden)

    Jesse Whittington

    Full Text Available Capture-recapture studies are frequently used to monitor the status and trends of wildlife populations. Detection histories from individual animals are used to estimate probability of detection and abundance or density. The accuracy of abundance and density estimates depends on the ability to model factors affecting detection probability. Non-spatial capture-recapture models have recently evolved into spatial capture-recapture models that directly include the effect of distances between an animal's home range centre and trap locations on detection probability. Most studies comparing non-spatial and spatial capture-recapture biases focussed on single year models and no studies have compared the accuracy of demographic parameter estimates from open population models. We applied open population non-spatial and spatial capture-recapture models to three years of grizzly bear DNA-based data from Banff National Park and simulated data sets. The two models produced similar estimates of grizzly bear apparent survival, per capita recruitment, and population growth rates but the spatial capture-recapture models had better fit. Simulations showed that spatial capture-recapture models produced more accurate parameter estimates with better credible interval coverage than non-spatial capture-recapture models. Non-spatial capture-recapture models produced negatively biased estimates of apparent survival and positively biased estimates of per capita recruitment. The spatial capture-recapture grizzly bear population growth rates and 95% highest posterior density averaged across the three years were 0.925 (0.786-1.071 for females, 0.844 (0.703-0.975 for males, and 0.882 (0.779-0.981 for females and males combined. The non-spatial capture-recapture population growth rates were 0.894 (0.758-1.024 for females, 0.825 (0.700-0.948 for males, and 0.863 (0.771-0.957 for both sexes. The combination of low densities, low reproductive rates, and predominantly negative

  11. A Comparison of Grizzly Bear Demographic Parameters Estimated from Non-Spatial and Spatial Open Population Capture-Recapture Models.

    Science.gov (United States)

    Whittington, Jesse; Sawaya, Michael A

    2015-01-01

    Capture-recapture studies are frequently used to monitor the status and trends of wildlife populations. Detection histories from individual animals are used to estimate probability of detection and abundance or density. The accuracy of abundance and density estimates depends on the ability to model factors affecting detection probability. Non-spatial capture-recapture models have recently evolved into spatial capture-recapture models that directly include the effect of distances between an animal's home range centre and trap locations on detection probability. Most studies comparing non-spatial and spatial capture-recapture biases focussed on single year models and no studies have compared the accuracy of demographic parameter estimates from open population models. We applied open population non-spatial and spatial capture-recapture models to three years of grizzly bear DNA-based data from Banff National Park and simulated data sets. The two models produced similar estimates of grizzly bear apparent survival, per capita recruitment, and population growth rates but the spatial capture-recapture models had better fit. Simulations showed that spatial capture-recapture models produced more accurate parameter estimates with better credible interval coverage than non-spatial capture-recapture models. Non-spatial capture-recapture models produced negatively biased estimates of apparent survival and positively biased estimates of per capita recruitment. The spatial capture-recapture grizzly bear population growth rates and 95% highest posterior density averaged across the three years were 0.925 (0.786-1.071) for females, 0.844 (0.703-0.975) for males, and 0.882 (0.779-0.981) for females and males combined. The non-spatial capture-recapture population growth rates were 0.894 (0.758-1.024) for females, 0.825 (0.700-0.948) for males, and 0.863 (0.771-0.957) for both sexes. The combination of low densities, low reproductive rates, and predominantly negative population growth

  12. Evaluating estimators for numbers of females with cubs-of-the-year in the Yellowstone grizzly bear population

    Science.gov (United States)

    Cherry, S.; White, G.C.; Keating, K.A.; Haroldson, Mark A.; Schwartz, Charles C.

    2007-01-01

    Current management of the grizzly bear (Ursus arctos) population in Yellowstone National Park and surrounding areas requires annual estimation of the number of adult female bears with cubs-of-the-year. We examined the performance of nine estimators of population size via simulation. Data were simulated using two methods for different combinations of population size, sample size, and coefficient of variation of individual sighting probabilities. We show that the coefficient of variation does not, by itself, adequately describe the effects of capture heterogeneity, because two different distributions of capture probabilities can have the same coefficient of variation. All estimators produced biased estimates of population size with bias decreasing as effort increased. Based on the simulation results we recommend the Chao estimator for model M h be used to estimate the number of female bears with cubs of the year; however, the estimator of Chao and Shen may also be useful depending on the goals of the research.

  13. Stress and reproductive hormones in grizzly bears reflect nutritional benefits and social consequences of a salmon foraging niche.

    Directory of Open Access Journals (Sweden)

    Heather M Bryan

    Full Text Available Physiological indicators of social and nutritional stress can provide insight into the responses of species to changes in food availability. In coastal British Columbia, Canada, grizzly bears evolved with spawning salmon as an abundant but spatially and temporally constrained food source. Recent and dramatic declines in salmon might have negative consequences on bear health and ultimately fitness. To examine broadly the chronic endocrine effects of a salmon niche, we compared cortisol, progesterone, and testosterone levels in hair from salmon-eating bears from coastal BC (n = 75 with the levels in a reference population from interior BC lacking access to salmon (n = 42. As predicted, testosterone was higher in coastal bears of both sexes relative to interior bears, possibly reflecting higher social density on the coast mediated by salmon availability. We also investigated associations between the amount of salmon individual bears consumed (as measured by stable isotope analysis and cortisol and testosterone in hair. Also as predicted, cortisol decreased with increasing dietary salmon and was higher after a year of low dietary salmon than after a year of high dietary salmon. These findings at two spatial scales suggest that coastal bears might experience nutritional or social stress in response to on-going salmon declines, providing novel insights into the effects of resource availability on fitness-related physiology.

  14. Stress and reproductive hormones in grizzly bears reflect nutritional benefits and social consequences of a salmon foraging niche.

    Science.gov (United States)

    Bryan, Heather M; Darimont, Chris T; Paquet, Paul C; Wynne-Edwards, Katherine E; Smits, Judit E G

    2013-01-01

    Physiological indicators of social and nutritional stress can provide insight into the responses of species to changes in food availability. In coastal British Columbia, Canada, grizzly bears evolved with spawning salmon as an abundant but spatially and temporally constrained food source. Recent and dramatic declines in salmon might have negative consequences on bear health and ultimately fitness. To examine broadly the chronic endocrine effects of a salmon niche, we compared cortisol, progesterone, and testosterone levels in hair from salmon-eating bears from coastal BC (n = 75) with the levels in a reference population from interior BC lacking access to salmon (n = 42). As predicted, testosterone was higher in coastal bears of both sexes relative to interior bears, possibly reflecting higher social density on the coast mediated by salmon availability. We also investigated associations between the amount of salmon individual bears consumed (as measured by stable isotope analysis) and cortisol and testosterone in hair. Also as predicted, cortisol decreased with increasing dietary salmon and was higher after a year of low dietary salmon than after a year of high dietary salmon. These findings at two spatial scales suggest that coastal bears might experience nutritional or social stress in response to on-going salmon declines, providing novel insights into the effects of resource availability on fitness-related physiology.

  15. Dietary protein content alters energy expenditure and composition of the mass gain in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Felicetti, Laura A; Robbins, Charles T; Shipley, Lisa A

    2003-01-01

    Many fruits contain high levels of available energy but very low levels of protein and other nutrients. The discrepancy between available energy and protein creates a physiological paradox for many animals consuming high-fruit diets, as they will be protein deficient if they eat to meet their minimum energy requirement. We fed young grizzly bears both high-energy pelleted and fruit diets containing from 1.6% to 15.4% protein to examine the role of diet-induced thermogenesis and fat synthesis in dealing with high-energy-low-protein diets. Digestible energy intake at mass maintenance increased 2.1 times, and composition of the gain changed from primarily lean mass to entirely fat when the protein content of the diet decreased from 15.4% to 1.6%. Daily fat gain was up to three times higher in bears fed low-protein diets ad lib., compared with bears consuming the higher-protein diet and gaining mass at the same rate. Thus, bears eating fruit can either consume other foods to increase dietary protein content and reduce energy expenditure, intake, and potentially foraging time or overeat high-fruit diets and use diet-induced thermogenesis and fat synthesis to deal with their skewed energy-to-protein ratio. These are not discrete options but a continuum that creates numerous solutions for balancing energy expenditure, intake, foraging time, fat accumulation, and ultimately fitness, depending on food availability, foraging efficiency, bear size, and body condition.

  16. Assessment of pesticide residues in army cutworm moths (Euxoa auxiliaris) from the Greater Yellowstone Ecosystem and their potential consequences to foraging grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    Robison, Hillary L; Schwartz, Charles C; Petty, Jim D; Brussard, Peter F

    2006-09-01

    During summer, a grizzly bear (Ursus arctos horribilis) in the Greater Yellowstone Ecosystem (GYE) (USA) can excavate and consume millions of army cutworm moths (Euxoa auxiliaris) (ACMs) that aggregate in high elevation talus. Grizzly bears in the GYE were listed as threatened by the US Fish and Wildlife Service in 1975 and were proposed for delisting in 2005. However, questions remain about key bear foods. For example, ACMs are agricultural pests and concern exists about whether they contain pesticides that could be toxic to bears. Consequently, we investigated whether ACMs contain and transport pesticides to bear foraging sites and, if so, whether these levels could be toxic to bears. In 1999 we collected and analyzed ACMs from six bear foraging sites. ACMs were screened for 32 pesticides with gas chromatography with electron capture detection (GC-ECD). Because gas chromatography with tandem mass spectrometry (GC-MS/MS) can be more sensitive than GC-ECD for certain pesticides, we revisited one site in 2001 and analyzed these ACMs with GC-MS/MS. ACMs contained trace or undetectable levels of pesticides in 1999 and 2001, respectively. Based on chemical levels in ACMs and numbers of ACMs a bear can consume, we calculated the potential of chemicals to reach physiological toxicity. These calculations indicate bears do not consume physiologically toxic levels of pesticides and allay concerns they are at risk from pesticides transported by ACMs. If chemical control of ACMs changes in the future, screening new ACM samples taken from bear foraging sites may be warranted.

  17. Interthalamic hematoma secondary to cerebrovascular atherosclerosis in an aged grizzly bear (Ursus arctos horribilis) with primary cardiac schwannoma.

    Science.gov (United States)

    Miller, Andrew David; McDonough, Sean

    2008-12-01

    A 38-year-old intact female Grizzly bear (Ursus arctos horribilis) was evaluated for progressive seizure activity, pale mucous membranes, deficient pupillary light and menace responses, and irregular shallow respiration. Because of poor response to treatment, the animal was euthanized. Gross examination revealed abundant hemorrhage in both lateral ventricles; a large, encapsulated mass within the rostral interthalamic region; and a well-demarcated, round white mass in the apex of the right ventricle. Histologic examination of the interthalamic mass revealed a resolving hematoma composed of stratified layers of fibrin and white blood cells that was surrounded by a thick fibrous capsule. Most meningeal and intraparenchymal blood vessels had multifocal degeneration, fragmentation, and fraying of the internal elastic lamina with prominent intimal proliferations and plaques. The plaques were formed by small numbers of lipid-laden macrophages (foam cells) that were intermixed with occasional lymphocytes and plasma cells. The cardiac mass was composed of pallisading and interlacing spindle cells with parallel nuclei and abundant, pale eosinophilic cytoplasm consistent with a schwannoma.

  18. Positive Reinforcement Training for Blood Collection in Grizzly Bears (Ursus arctos horribilis) Results in Undetectable Elevations in Serum Cortisol Levels: A Preliminary Investigation.

    Science.gov (United States)

    Joyce-Zuniga, Nicole M; Newberry, Ruth C; Robbins, Charles T; Ware, Jasmine V; Jansen, Heiko T; Nelson, O Lynne

    2016-01-01

    Training nonhuman animals in captivity for participation in routine husbandry procedures is believed to produce a lower stress environment compared with undergoing a general anesthetic event for the same procedure. This hypothesis rests largely on anecdotal evidence that the captive subjects appear more relaxed with the trained event. Blood markers of physiological stress responses were evaluated in 4 captive grizzly bears (Ursus arctos horribilis) who were clicker-trained for blood collection versus 4 bears who were chemically immobilized for blood collection. Serum cortisol and immunoglobulin A (IgA) and plasma β-endorphin were measured as indicators of responses to stress. Plasma β-endorphin was not different between the groups. Serum IgA was undetectable in all bears. Serum cortisol was undetectable in all trained bears, whereas chemically immobilized bears had marked cortisol elevations (p positive reinforcement training for routine health procedures to minimize anxiety.

  19. Mating-related behaviour of grizzly bears inhabiting marginal habitat at the periphery of their North American range.

    Science.gov (United States)

    Edwards, Mark A; Derocher, Andrew E

    2015-02-01

    In comparison to core populations, peripheral populations have low density and recruitment, and are subject to different selective pressures, such as environmental conditions, food type and availability, predation, disease, etc., which may result in behavioural modifications to mating. We test the roam-to-mate hypothesis for a peripheral population of grizzly bears (Ursus arctos) at the northern extent of their North American range, in Canada's Arctic. If bears are roaming-to-mate, we predicted greater range size and daily displacement, and more linear movements for receptive animals during the mating period compared to post-mating. In contrast to our predictions, we found that in general range size and displacement increased from mating to post-mating regardless of reproductive status. When considered across both periods, females with cubs-of-the-year had smaller range use metrics than other reproductive groups, which we attribute to a counter-strategy against sexually selected infanticide and the reduced mobility of cubs. Linearity of movements remained near zero during both periods across all groups, suggesting tortuous movements more characteristic of foraging than of mate-searching. We suggest that for this population, finding quality habitat takes precedence over mate-searching in this marginal Arctic landscape. Alternatively, a more monogamous mating system and sequestering behaviour may have obscured movement differences between the two periods. The behavioural differences in mating that we observed from what is typical of core populations may reflect local adaptation to marginal conditions and could benefit the species in the face of ongoing environmental change.

  20. Genetic relationships of grizzly bears (Ursus arctos) in the Prudhoe Bay region of Alaska: inference from microsatellite DNA, mitochondrial DNA, and field observations.

    Science.gov (United States)

    Cronin, M; Shideler, R; Hechtel, J; Strobeck, C; Paetkau, D

    1999-01-01

    Grizzly bears are abundant in the region of the Prudhoe Bay oil fields in northern Alaska. We used field observations and molecular genetic data to identify parent-offspring and sibling relationships among bears in this region. We determined genotypes at 14 microsatellite DNA loci and the cytochrome b gene of mitochondrial DNA (mtDNA) for 36 bears. We identified 17 possible mother-offspring pairs and 8 possible father-offspring pairs. This includes verification of the relationships of 14 mother-offspring pairs identified from field observations. Three additional mother-offspring pairs and all eight father-offspring pairs were determined from genetic and age data. Relatedness coefficients based on numbers of shared alleles between individuals were as expected: approximately 0.50 for parent-offspring and sibling pairs and approximately 0.75 for a father-offspring pair resulting from a father-daughter mating. The level of genetic variation (mean number of alleles per locus = 6.6, mean heterozygosity = 70%) and allele frequencies in grizzly bears in the Prudhoe Bay region are similar to those in other parts of the species' range.

  1. Landscape features and attractants that predispose grizzly bears to risk of conflicts with humans: A spatial and temporal analysis on privately owned agricultural land

    Science.gov (United States)

    Wilson, Seth Mark

    Grizzly bear (Ursus arctos) deaths in the US tend to be concentrated on the periphery of core habitats. These deaths were often preceded by conflicts with humans. Management removals of "nuisance" and or habituated grizzly bears are a leading cause of death in many populations. This exploratory study focuses on the conditions that lead to human-grizzly bear conflicts on private lands near core habitat. I examined spatial associations among reported human-grizzly bear conflicts during 1986--2001, landscape features, and agricultural-attractants in north-central Montana. I surveyed 61 of a possible 64 active livestock related land users and I used geographic information system (GIS) techniques to collect information on cattle and sheep pasture locations, seasons of use, and bone yard (carcass dumps) and beehive locations. I used GIS spatial analyses, univariate tests, and logistic regression models to explore the associations among conflicts, landscape features, and attractants. A majority (75%) of conflicts were found in distinct seasonal conflict hotspots. Conflict hotspots with spatial overlap were associated with riparian vegetation, bone yards, and beehives in close proximity to one another and accounted for 62% of all conflicts. Consistently available seasonal attractants in overlapping hotspots such as calving areas, sheep lambing areas and spring, summer, and fall sheep and cattle pastures appear to perpetuate the occurrence of conflicts. I found that lambing areas and spring and summer sheep pastures were strongly associated with conflict locations as were cattle calving areas, spring cow/calf pastures, fall pastures, and bone yards. Logistic regression modeling revealed that the presence of riparian vegetation within a 1.6 km search radius strongly influenced the likelihood of conflict. After controlling for riparian vegetation, I found that unmanaged bone yards, unfenced and fenced beehives, all increased the odds of conflict. For every 1 km moved away

  2. Environmental factors and habitat use influence body condition of individuals in a species at risk, the grizzly bear.

    Science.gov (United States)

    Bourbonnais, Mathieu L; Nelson, Trisalyn A; Cattet, Marc R L; Darimont, Chris T; Stenhouse, Gordon B; Janz, David M

    2014-01-01

    Metrics used to quantify the condition or physiological states of individuals provide proactive mechanisms for understanding population dynamics in the context of environmental factors. Our study examined how anthropogenic disturbance, habitat characteristics and hair cortisol concentrations interpreted as a sex-specific indicator of potential habitat net-energy demand affect the body condition of grizzly bears (n = 163) in a threatened population in Alberta, Canada. We quantified environmental variables by modelling spatial patterns of individual habitat use based on global positioning system telemetry data. After controlling for gender, age and capture effects, we assessed the influence of biological and environmental variables on body condition using linear mixed-effects models in an information theoretical approach. Our strongest model suggested that body condition was improved when patterns of habitat use included greater vegetation productivity, increased influence of forest harvest blocks and oil and gas well sites, and a higher percentage of regenerating and coniferous forest. However, body condition was negatively affected by habitat use in close proximity to roads and in areas where potential energetic demands were high. Poor body condition was also associated with increased selection of parks and protected areas and greater seasonal vegetation productivity. Adult females, females with cubs-of-year, juvenile females and juvenile males were in poorer body condition compared with adult males, suggesting that intra-specific competition and differences in habitat use based on gender and age may influence body condition dynamics. Habitat net-energy demand also tended to be higher in areas used by females which, combined with observed trends in body condition, could affect reproductive success in this threatened population. Our results highlight the importance of considering spatiotemporal variability in environmental factors and habitat use when assessing

  3. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet

    Energy Technology Data Exchange (ETDEWEB)

    Noël, Marie, E-mail: marie.noel@stantec.com [Stantec Consulting Ltd. 2042 Mills Road, Unit 11, Sidney BC V8L 4X2 (Canada); Christensen, Jennie R., E-mail: jennie.christensen@stantec.com [Stantec Consulting Ltd. 2042 Mills Road, Unit 11, Sidney BC V8L 4X2 (Canada); Spence, Jody, E-mail: jodys@uvic.ca [School of Earth and Ocean Sciences, Bob Wright Centre A405, University of Victoria, PO BOX 3065 STN CSC, Victoria, BC V8W 3V6 (Canada); Robbins, Charles T., E-mail: ctrobbins@wsu.edu [School of the Environment and School of Biological Sciences, Washington State University, Pullman, WA 99164-4236 (United States)

    2015-10-01

    We enhanced an existing technique, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to function as a non-lethal tool in the temporal characterization of trace element exposure in wild mammals. Mercury (Hg), copper (Cu), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) were analyzed along the hair of captive and wild grizzly bears (Ursus arctos horribilis). Laser parameters were optimized (consecutive 2000 μm line scans along the middle line of the hair at a speed of 50 μm/s; spot size = 30 μm) for consistent ablation of the hair. A pressed pellet of reference material DOLT-2 and sulfur were used as external and internal standards, respectively. Our newly adapted method passed the quality control tests with strong correlations between trace element concentrations obtained using LA-ICP-MS and those obtained with regular solution-ICP-MS (r{sup 2} = 0.92, 0.98, 0.63, 0.57, 0.99 and 0.90 for Hg, Fe, Cu, Zn, Cd and Pb, respectively). Cross-correlation analyses revealed good reproducibility between trace element patterns obtained from hair collected from the same bear. One exception was Cd for which external contamination was observed resulting in poor reproducibility. In order to validate the method, we used LA-ICP-MS on the hair of five captive grizzly bears fed known and varying amounts of cutthroat trout over a period of 33 days. Trace element patterns along the hair revealed strong Hg, Cu and Zn signals coinciding with fish consumption. Accordingly, significant correlations between Hg, Cu, and Zn in the hair and Hg, Cu, and Zn intake were evident and we were able to develop accumulation models for each of these elements. While the use of LA-ICP-MS for the monitoring of trace elements in wildlife is in its infancy, this study highlights the robustness and applicability of this newly adapted method. - Highlights: • LA-ICP-MS provides temporal trace metal exposure information for wild grizzly bears. • Cu and Zn temporal exposures provide

  4. Short-term impacts of a 4-lane highway on black bears in eastern North Carolina

    Science.gov (United States)

    Van Manen, Frank T.; McCollister, Matthew F.; Nicholson, Jeremy M.; Thompson, Laura M.; Kindall, Jason L.; Jones, Mark D.

    2012-01-01

    Among numerous anthropogenic impacts on terrestrial landscapes, expanding transportation networks represent one of the primary challenges to wildlife conservation worldwide. Larger mammals may be particularly vulnerable because of typically low densities, low reproductive rates, and extensive movements. Although numerous studies have been conducted to document impacts of road networks on wildlife, inference has been limited because of experimental design limitations. During the last decade, the North Carolina Department of Transportation (NCDOT) rerouted and upgraded sections of United States Highway 64 between Raleigh and the Outer Banks to a 4-lane, divided highway. A new route was selected for a 24.1-km section in Washington County. The new section of highway included 3 wildlife underpasses with adjacent wildlife fencing to mitigate the effects of the highway on wildlife, particularly American black bears (Ursus americanus). We assessed the short-term impacts of the new highway on spatial ecology, population size, survival, occupancy, and gene flow of black bears. We tested our research hypotheses using a before-after control-impact (BACI) study design. We collected data during 2000–2001 (preconstruction phase) and 2006–2007 (postconstruction phase) in the highway project area and a nearby control area (each approx. 11,000 ha), resulting in 4 groups of data (i.e., pre- or postconstruction study phase, treatment or control area). We captured and radiocollared 57 bears and collected 5,775 hourly locations and 4,998 daily locations. Using mixed-model analysis of variance and logistic regression, we detected no differences in home ranges, movement characteristics, proximity to the highway alignment, or habitat use between the 2 study phases, although minimum detectable effect sizes were large for several tests. However, after completion of the new highway, bears on the treatment area became less inactive in morning, when highway traffic was low, compared with

  5. Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet.

    Science.gov (United States)

    Noël, Marie; Christensen, Jennie R; Spence, Jody; Robbins, Charles T

    2015-10-01

    We enhanced an existing technique, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to function as a non-lethal tool in the temporal characterization of trace element exposure in wild mammals. Mercury (Hg), copper (Cu), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) were analyzed along the hair of captive and wild grizzly bears (Ursus arctos horribilis). Laser parameters were optimized (consecutive 2000 μm line scans along the middle line of the hair at a speed of 50 μm/s; spot size=30 μm) for consistent ablation of the hair. A pressed pellet of reference material DOLT-2 and sulfur were used as external and internal standards, respectively. Our newly adapted method passed the quality control tests with strong correlations between trace element concentrations obtained using LA-ICP-MS and those obtained with regular solution-ICP-MS (r(2)=0.92, 0.98, 0.63, 0.57, 0.99 and 0.90 for Hg, Fe, Cu, Zn, Cd and Pb, respectively). Cross-correlation analyses revealed good reproducibility between trace element patterns obtained from hair collected from the same bear. One exception was Cd for which external contamination was observed resulting in poor reproducibility. In order to validate the method, we used LA-ICP-MS on the hair of five captive grizzly bears fed known and varying amounts of cutthroat trout over a period of 33 days. Trace element patterns along the hair revealed strong Hg, Cu and Zn signals coinciding with fish consumption. Accordingly, significant correlations between Hg, Cu, and Zn in the hair and Hg, Cu, and Zn intake were evident and we were able to develop accumulation models for each of these elements. While the use of LA-ICP-MS for the monitoring of trace elements in wildlife is in its infancy, this study highlights the robustness and applicability of this newly adapted method.

  6. Genetic connectivity for two bear species at wildlife crossing structures in Banff National Park.

    Science.gov (United States)

    Sawaya, Michael A; Kalinowski, Steven T; Clevenger, Anthony P

    2014-04-01

    Roads can fragment and isolate wildlife populations, which will eventually decrease genetic diversity within populations. Wildlife crossing structures may counteract these impacts, but most crossings are relatively new, and there is little evidence that they facilitate gene flow. We conducted a three-year research project in Banff National Park, Alberta, to evaluate the effectiveness of wildlife crossings to provide genetic connectivity. Our main objective was to determine how the Trans-Canada Highway and crossing structures along it affect gene flow in grizzly (Ursus arctos) and black bears (Ursus americanus). We compared genetic data generated from wildlife crossings with data collected from greater bear populations. We detected a genetic discontinuity at the highway in grizzly bears but not in black bears. We assigned grizzly bears that used crossings to populations north and south of the highway, providing evidence of bidirectional gene flow and genetic admixture. Parentage tests showed that 47% of black bears and 27% of grizzly bears that used crossings successfully bred, including multiple males and females of both species. Differentiating between dispersal and gene flow is difficult, but we documented gene flow by showing migration, reproduction and genetic admixture. We conclude that wildlife crossings allow sufficient gene flow to prevent genetic isolation.

  7. Audubon Wildlife Adventures. Grizzly Guidebook. School Edition.

    Science.gov (United States)

    National Audubon Society, Washington, DC.

    This program introduces the young computer players to the world of the grizzly bear, the largest land carnivore in North America. Through a series of four interactive stories, players learn of the bear's habits and human activities that have brought it close to extinction. Playing the part of a park ranger, a research biologist or a natural…

  8. Preserving a spirit of place: U.S. Highway 93 on the Flathead Indian Reservation

    OpenAIRE

    Marshik, Joel; Renz, Lyle; Sipes, Jim; Becker, Dale; Paulson, Dale

    2001-01-01

    US Highway 93 traverses the Flathead Indian Reservation, which is located on the west side of the Rocky Mountains in western Montana. Picturesque mountains and mountain valleys, with the broad Flathead Valley to the North and the majestic Mission Mountains to the East, characterize this part of Montana. The area is home to a wide variety of wildlife, including grizzly bear, white-tailed deer, mule deer, pronghorn, elk, painted turtles, bighorn sheep, and a number of fish and bird species. It ...

  9. Insights into the latent multinomial model through mark-resight data on female grizzly bears with cubs-of-the-year

    Science.gov (United States)

    Higgs, Megan D.; Link, William; White, Gary C.; Haroldson, Mark A.; Bjornlie, Daniel D

    2013-01-01

    Mark-resight designs for estimation of population abundance are common and attractive to researchers. However, inference from such designs is very limited when faced with sparse data, either from a low number of marked animals, a low probability of detection, or both. In the Greater Yellowstone Ecosystem, yearly mark-resight data are collected for female grizzly bears with cubs-of-the-year (FCOY), and inference suffers from both limitations. To overcome difficulties due to sparseness, we assume homogeneity in sighting probabilities over 16 years of bi-annual aerial surveys. We model counts of marked and unmarked animals as multinomial random variables, using the capture frequencies of marked animals for inference about the latent multinomial frequencies for unmarked animals. We discuss undesirable behavior of the commonly used discrete uniform prior distribution on the population size parameter and provide OpenBUGS code for fitting such models. The application provides valuable insights into subtleties of implementing Bayesian inference for latent multinomial models. We tie the discussion to our application, though the insights are broadly useful for applications of the latent multinomial model.

  10. Increased cardiac alpha-myosin heavy chain in left atria and decreased myocardial insulin-like growth factor (Igf-I) expression accompany low heart rate in hibernating grizzly bears.

    Science.gov (United States)

    Barrows, N D; Nelson, O L; Robbins, C T; Rourke, B C

    2011-01-01

    Grizzly bears (Ursus arctos horribilis) tolerate extended periods of extremely low heart rate during hibernation without developing congestive heart failure or cardiac chamber dilation. Left ventricular atrophy and decreased left ventricular compliance have been reported in this species during hibernation. We evaluated the myocardial response to significantly reduced heart rate during hibernation by measuring relative myosin heavy-chain (MyHC) isoform expression and expression of a set of genes important to muscle plasticity and mass regulation in the left atria and left ventricles of active and hibernating bears. We supplemented these data with measurements of systolic and diastolic function via echocardiography in unanesthetized grizzly bears. Atrial strain imaging revealed decreased atrial contractility, decreased expansion/reservoir function (increased atrial stiffness), and decreased passive-filling function (increased ventricular stiffness) in hibernating bears. Relative MyHC-α protein expression increased significantly in the atrium during hibernation. The left ventricle expressed 100% MyHC-β protein in both groups. Insulin-like growth factor (IGF-I) mRNA expression was reduced by ∼50% in both chambers during hibernation, consistent with the ventricular atrophy observed in these bears. Interestingly, mRNA expression of the atrophy-related ubiquitin ligases Muscle Atrophy F-box (MAFBx) and Muscle Ring Finger 1 did not increase, nor did expression of myostatin or hypoxia-inducible factor 1α (HIF-1α). We report atrium-specific decreases of 40% and 50%, respectively, in MAFBx and creatine kinase mRNA expression during hibernation. Decreased creatine kinase expression is consistent with lowered energy requirements and could relate to reduced atrial emptying function during hibernation. Taken together with our hemodynamic assessment, these data suggest a potential downregulation of atrial chamber function during hibernation to prevent fatigue and dilation

  11. The salmon bears: giants of the great bear rainforest

    National Research Council Canada - National Science Library

    McAllister, I; Read, N

    2010-01-01

    The Salmon Bears explores the delicate balance that exists between the grizzly, black and spirit bears of the Great Bear Rainforest and their natural environment on the central coast of British Columbia...

  12. Grizzly Usage and Theory Manual

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B. W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Backman, M. [Univ. of Tennessee, Knoxville, TN (United States); Chakraborty, P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwen, D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Y. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Huang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bai, X. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, W. [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Grizzly is a multiphysics simulation code for characterizing the behavior of nuclear power plant (NPP) structures, systems and components (SSCs) subjected to a variety of age-related aging mechanisms. Grizzly simulates both the progression of aging processes, as well as the capacity of aged components to safely perform. This initial beta release of Grizzly includes capabilities for engineering-scale thermo-mechanical analysis of reactor pressure vessels (RPVs). Grizzly will ultimately include capabilities for a wide range of components and materials. Grizzly is in a state of constant development, and future releases will broaden the capabilities of this code for RPV analysis, as well as expand it to address degradation in other critical NPP components.

  13. Bears, Big and Little. Young Discovery Library Series.

    Science.gov (United States)

    Pfeffer, Pierre

    This book is written for children 5 through 10. Part of a series designed to develop their curiosity, fascinate them and educate them, this volume describes: (1) the eight species of bears, including black bear, brown bear, grizzly bear, spectacled bear, sun bear, sloth bear, polar bear, and giant panda; (2) geographical habitats of bears; (3)…

  14. GRIZZLY/FAVOR Interface Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, Terry L [ORNL; Williams, Paul T [ORNL; Yin, Shengjun [ORNL; Klasky, Hilda B [ORNL; Tadinada, Sashi [ORNL; Bass, Bennett Richard [ORNL

    2013-06-01

    As part of the Light Water Reactor Sustainability (LWRS) Program, the objective of the GRIZZLY/FAVOR Interface project is to create the capability to apply GRIZZLY 3-D finite element (thermal and stress) analysis results as input to FAVOR probabilistic fracture mechanics (PFM) analyses. The one benefit of FAVOR to Grizzly is the PROBABILISTIC capability. This document describes the implementation of the GRIZZLY/FAVOR Interface, the preliminary verification and tests results and a user guide that provides detailed step-by-step instructions to run the program.

  15. Bear

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The famous physicist made for his scholars this riddle. A fellow encountered a bear in a wasteland. There was nobody else there. Both were frightened and ran away. Fellow to the north, bear to the west. Suddenly the fellow stopped, aimed his gun to the south and shot the bear. What colour was the bear?

  16. In bear country: peaceful co-existence with a touchy wilderness icon starting to look possible

    Energy Technology Data Exchange (ETDEWEB)

    Podlubny, J.

    2002-10-07

    How oil and gas companies have harnessed location data maps and satellite communication technology to help resource developers to map out new roads and pipelines in the grizzly bear habitat of western Alberta is described. The high-tech approach is part of the Foot Hills Model Forest Grizzly Bear Study project, operating out of Hinton, Alberta, which focuses on the effects of industrial activity on the Alberta grizzly bear. Since the project's inception three years ago a library of data has been collected with a tool known as the GPS collar. This collar attached to more than 70 bears enabled scientists to add new dimensions of precision and intimacy to the tracking of grizzly bears. The maps created from data captured by the collars have been used by forestry and oil and gas industry personnel to help establish working relationships with grizzly bears by using the information as a guide to decisions on which routes are best suited for road and pipeline projects, i.e. which ones can be forecast to have the least effect on bears. The study is the first that has generated scientific information which is being used in a practical way to help preserve grizzly bears in the wild. At least one pipeline route has been changed when the company found out, through the mapping technology, that an area affected by the originally proposed route was an important grizzly bear habitat. The information also has been used in conjunction with developing new roads, mining locations and other activities that involve grizzly bear habitats. In addition to these practical industry-related applications the study also focuses on collecting new information about grizzly bears, clearing up bear myths, making discoveries about bear DNA, creating new trapping techniques and the best drugs to use when putting on collars and ear tags.

  17. Compression Tests of Plain Chloroprene Rubber Bearings of Highway Bridge under Acid Corrosion Condition%硝酸腐蚀条件下公路桥梁板式氯丁橡胶支座受压试验

    Institute of Scientific and Technical Information of China (English)

    张延年; 司月华; 张军; 刘圣杰; 郑怡

    2013-01-01

    目的 研究硝酸腐蚀条件下公路桥梁板式氯丁橡胶支座受压性能的变化规律.方法 采用pH =4.5的硝酸溶液对公路桥梁板式氯丁橡胶支座进行20 d、40d、60 d、80 d、100 d的全浸泡处理,利用5 000 kN的压力试验机进行轴心受压试验,从承载力、极限抗压强度、抗压弹性模量、竖向刚度对腐蚀试件与标准件进行对比分析.结果 经硝酸腐蚀后,氯丁橡胶支座的抗压弹性阶段变短,且破坏更加严重;其承载力、极限抗压强度、抗压弹性模量随处理天数的增加而逐渐下降.结论 采用最小二乘法对使用0 ~50年后的橡胶支座的抗压强度和弹性模量进行分析,其衰减函数及衰减曲线大致符合指数函数的变化规律.%This paper studies compression performance change rules of highway bridge slab neoprene bearing under acid corrosion conditions.Do the full immersion treatment of 20 d,40 d,60 d,80 d,100 d on highway bridge slab neoprene bearing using pH =4.5 nitric acid solution,use 5 000 kN pressure tester for axial compression experiments,and compare the corrosion specimen to standard parts form analyzing bearing capacity,ultimate compressive strength,compressive elastic modulus,the vertical stiffness and so on.The experiment results show that the compressive elastic stage of neoprene bearings becomes shorter and the damage is more serious after the acid corrosion;Its bearing capacity,ultimate compressive strength,compressive elastic modulus gradually decline along with the processing days increasing.Analyze compressive strength and elastic modulus of the rubber bearing which are used for 0 ~ 50 years by using the least square method,its attenuation formula and decay curve are broadly in line with the changing rule of the exponential function.

  18. Grizzly Substation Fiber Optics : Environmental Assessment.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1998-02-01

    This notice announces BPA`s decision to construct, operate, and maintain the Grizzly Substation Fiber Optic Project (Project). This Project is part of a continuing effort by BPA to complete a regionwide upgrade of its existing telecommunications system. The US Forest Service and BPA jointly prepared the Grizzly Substation Fiber Optic Project Environmental Assessment (EA) (DOE/EA-1241) evaluating the potential environmental impacts of the Proposed Action, the Underground Installation Alternative, and the No Action Alternative. Based on the analysis in the EA, the US Forest Service and BPA have determined that the Proposed Action is not a major Federal action significantly affecting the quality of the human environment, within the meaning of the National Environmental Policy Act (NEPA) of 1969. Therefore, the preparation of an Environmental Impact Statement (EIS) is not required and BPA is issuing this FONSI. The US Forest Service has separately issued a FONSI and Decision Notice authorizing BPA to construct, operate, and maintain the Project within the Crooked River National Grassland (Grassland).

  19. 浅析公路桥梁中板式橡胶支座设计%Simple Analysis on Laminated Rubber Bearing Design in Highway Bridge Construction

    Institute of Scientific and Technical Information of China (English)

    马少卿

    2015-01-01

    In this paper ,relevant law s and regulations about design methods of laminated rubber bearing are clarified and existing defects in design are further discussed .%本文主要对我国相关法律对公路桥梁中板式橡胶支座设计方法的规定进行了概述,进而探讨了公路桥梁中板式橡胶支座设计存在的漏洞。

  20. Safety distance for bearing members of long-span suspension bridge in highway fire%大跨径悬索桥承重构件公路火灾安全距离研究

    Institute of Scientific and Technical Information of China (English)

    李利军; 董晓明; 胡兆同

    2014-01-01

    In order to study the influence of highway fire on long-span suspension bridges and fill in the blank of suspension bridge fire research, combining structure fire analysis, an indirect coupling method was chosen to carry out the thermal-structure coupling analysis. Taking a 300 MW vehicle fire as an example, ANSYS was used to build the fire coordinate model of different section of a typi-cal suspension bridge. On the basis of fire research domestic and abroad, basing on the Ingason H. square growth model and taking the safety distance for cable bearing component of the long-span sus-pension bridge in highway fire as a research object, a numerical simulation for the safety distance of suspender cable and main cable was performed to reduce project risk and ensure the safety and sta-bility of the bridge. A thermal release rate mathematical model which suits highway fire study was put forward; The safety distance model in highway fire was established, and the size of combustion heat source and heat release rate of unit area were determined; With the thermal-structure coupling analysis, the fire safety distance for suspender cable and main cable of different diameters (0. 4 ~1. 0 m) were determined. The research results can provide some scientific basis for the fire resist-ance design of long-span suspension bridges.%为研究公路火灾对大跨径悬索桥带来的影响,弥补悬索桥火灾研究的空白,结合结构火灾分析的特点,确定选择间接耦合法进行热-结构耦合分析。以300 MW 车辆火灾为例,运用 ANSYS 有限元程序,建立了悬索桥不同断面的火灾坐标模型,在总结国内外火灾研究工作的基础上,基于 Ingason H.平方增长模型,以典型的大跨径悬索桥缆索承重构件的公路火灾安全距离为研究对象,以降低工程风险、保证大跨径悬索桥结构的安全性和稳定性为研究目标,对大跨径悬索桥吊索和主缆安全距离进行数值模拟,提出

  1. Immobilization of Wyoming bears using carfentanil and xylazine.

    Science.gov (United States)

    Kreeger, Terry J; Bjornlie, Dan; Thompson, Dan; Clapp, Justin; Clark, Colby; Hansen, Cole; Huizenga, Matt; Lockwood, Sam

    2013-07-01

    Seven grizzly (Ursus arctos; four male, three female) and three black (Ursus americanus; two male, one female) bears caught in culvert traps or leg snares were immobilized in northwestern Wyoming with carfentanil and xylazine at doses, respectively, of 0.011 ± 0.001 and 0.12 ± 0.01 mg/kg for grizzly bears and 0.014 ± 0.002 and 0.15 ± 0.04 mg/kg for black bears. These drugs were antagonized with 1 mg/kg naltrexone and 2 mg/kg tolazoline. Induction and recovery times, respectively, were 4.3 ± 0.5 and 7.1 ± 0.8 min for grizzly bears and 5.2 ± 0.4 and 9.1 ± 2.2 min for black bears. Inductions were smooth and uneventful. Recoveries were characterized initially by increased respiration followed by raising of the head, which quickly led to a full recovery, with the bears recognizing and avoiding humans and moving away, maneuvering around obstacles. All bears experienced respiratory depression, which did not significantly improve with supplemental oxygen on the basis of pulse oximetry (P=0.56). Rectal temperatures were normothermic. Carfentanil-xylazine immobilization of bears provided significant advantages over other drug regimens, including small drug volumes, predictable inductions, quick and complete recoveries, and lower costs. On the basis of these data, both grizzly and black bears can be immobilized effectively with 0.01 mg/kg carfentanil and 0.1 mg/kg xylazine.

  2. VT Limited Access Highways

    Data.gov (United States)

    Vermont Center for Geographic Information — A limited-access road, known by various terms worldwide, including limited-access highway, dual carriageway, expressway, and partial controlled access highway, is a...

  3. Contrasting past and current numbers of bears visiting Yellowstone cutthroat trout streams

    Science.gov (United States)

    Haroldson, Mark A.; Schwartz, Charles C.; , JUSTIN E. TEISBERG; , Kerry A. Gunther; , JENNIFER K. FORTIN; , CHARLES T. ROBBINS

    2014-01-01

    Spawning cutthroat trout (Oncorhynchus clarkii bouvieri) were historically abundant within tributary streams of Yellowstone Lake within Yellowstone National Park and were a highly digestible source of energy and protein for Yellowstone’s grizzly bears (Ursus arctos) and black bears (U. americanus). The cutthroat trout population has subsequently declined since the introduction of non-native lake trout (Salvelinus namaycush), and in response to effects of drought and whirling disease (Myxobolus cerebralis). The trout population, duration of spawning runs, and indices of bear use of spawning streams had declined in some regions of the lake by 1997–2000. We initiated a 3-year study in 2007 to assess whether numbers of spawning fish, black bears, and grizzly bears within and alongside stream corridors had changed since 1997– 2000. We estimated numbers of grizzly bears and black bears by first compiling encounter histories of individual bears visiting 48 hair-snag sites along 35 historically fished streams.We analyzed DNA encounter histories with Pradel-recruitment and Jolly-Seber (POPAN) capture-mark-recapture models. When compared to 1997–2000, the current number of spawning cutthroat trout per stream and the number of streams with cutthroat trout has decreased. We estimated that 48 (95% CI¼42–56) male and 23 (95% CI¼21–27) female grizzly bears visited the historically fished tributary streams during our study. In any 1- year, 46 to 59 independent grizzly bears (8–10% of estimated Greater Yellowstone Ecosystem population) visited these streams. When compared with estimates from the 1997 to 2000 study and adjusted for equal effort, the number of grizzly bears using the stream corridors decreased by 63%. Additionally, the number of black bears decreased between 64% and 84%. We also document an increased proportion of bears of both species visiting front-country (i.e., near human development) streams. With the recovery of cutthroat trout, we suggest bears

  4. Highway Bureau Director on Highway Construction

    Institute of Scientific and Technical Information of China (English)

    JINZHIGUO

    2005-01-01

    The Qinghai-Tibet Highway experienced four renovations in the past 40 years and has now been asphalted. For the fourth renovation, some 1.17 billion Yuan was consumed. It is now a modern highway. Extending 2,100 km from Xining of Qinghai to Lhasa of Tibet, it became 1,937 km after re-working. It goes 1,400 km in Qinghai.The Xining-Golmud section crossed many mountains and many rivers,extending 782 km. The Golmud-Lhasa section crosses four mountains—Kunlun Mountains (4,700 meters), Fenghuoshan Mountain (4,800 meters),Tanggula Mountain (5,150 meters above sea level at the mouth) and Nyainqentanggula Mountain, and crossed three rivers---Tongtianhe River, Tutu River and Curmar River with an average elevation of 4,500 meters. The Highway extends 544 km in Tibet. More than 80 percent of goods were transported through the highway.

  5. Crystal Plasticity Model of Reactor Pressure Vessel Embrittlement in GRIZZLY

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Pritam [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Biner, Suleyman Bulent [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Spencer, Benjamin Whiting [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

    2015-07-01

    The integrity of reactor pressure vessels (RPVs) is of utmost importance to ensure safe operation of nuclear reactors under extended lifetime. Microstructure-scale models at various length and time scales, coupled concurrently or through homogenization methods, can play a crucial role in understanding and quantifying irradiation-induced defect production, growth and their influence on mechanical behavior of RPV steels. A multi-scale approach, involving atomistic, meso- and engineering-scale models, is currently being pursued within the GRIZZLY project to understand and quantify irradiation-induced embrittlement of RPV steels. Within this framework, a dislocation-density based crystal plasticity model has been developed in GRIZZLY that captures the effect of irradiation-induced defects on the flow stress behavior and is presented in this report. The present formulation accounts for the interaction between self-interstitial loops and matrix dislocations. The model predictions have been validated with experiments and dislocation dynamics simulation.

  6. VT National Highway System (NHS)

    Data.gov (United States)

    Vermont Center for Geographic Information — The National Highway System (NHS) is a network of strategic highways within the United States, including the Interstate Highway System and other roads serving major...

  7. The history of effective population size and genetic diversity in the Yellowstone grizzly (Ursus arctos): implications for conservation.

    Science.gov (United States)

    Miller, Craig R; Waits, Lisette P

    2003-04-01

    Protein, mtDNA, and nuclear microsatellite DNA analyses have demonstrated that the Yellowstone grizzly bear has low levels of genetic variability compared with other Ursus arctos populations. Researchers have attributed this difference to inbreeding during a century of anthropogenic isolation and population size reduction. We test this hypothesis and assess the seriousness of genetic threats by generating microsatellite data for 110 museum specimens collected between 1912 and 1981. A loss of variability is detected, but it is much less severe than hypothesized. Variance in allele frequencies over time is used to estimate an effective population size of approximately 80 across the 20th century and >100 currently. The viability of the population is unlikely to be substantially reduced by genetic factors in the next several generations. However, gene flow from outside populations will be beneficial in avoiding inbreeding and the erosion of genetic diversity in the future.

  8. 3D J-Integral Capability in Grizzly

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin Spencer; Marie Backman; Pritam Chakraborty; William Hoffman

    2014-09-01

    This report summarizes work done to develop a capability to evaluate fracture contour J-Integrals in 3D in the Grizzly code. In the current fiscal year, a previously-developed 2D implementation of a J-Integral evaluation capability has been extended to work in 3D, and to include terms due both to mechanically-induced strains and due to gradients in thermal strains. This capability has been verified against a benchmark solution on a model of a curved crack front in 3D. The thermal term in this integral has been verified against a benchmark problem with a thermal gradient. These developments are part of a larger effort to develop Grizzly as a tool that can be used to predict the evolution of aging processes in nuclear power plant systems, structures, and components, and assess their capacity after being subjected to those aging processes. The capabilities described here have been developed to enable evaluations of Mode- stress intensity factors on axis-aligned flaws in reactor pressure vessels. These can be compared with the fracture toughness of the material to determine whether a pre-existing flaw would begin to propagate during a pos- tulated pressurized thermal shock accident. This report includes a demonstration calculation to show how Grizzly is used to perform a deterministic assessment of such a flaw propagation in a degraded reactor pressure vessel under pressurized thermal shock conditions. The stress intensity is calculated from J, and the toughness is computed using the fracture master curve and the degraded ductile to brittle transition temperature.

  9. Roadside bear viewing opportunities in Yellowstone National Park: characteristics, trends, and influence of whitebark pine

    Science.gov (United States)

    Haroldson, Mark A.; Gunther, Kerry

    2014-01-01

    Opportunities for viewing grizzly bears (Ursus arctos) and American black bears (U. americanus) from roadways in Yellowstone National Park (YNP) have increased in recent years. Unlike the panhandling bears common prior to the 1970s, current viewing usually involves bears feeding on natural foods. We define roadside bear viewing opportunities that cause traffic congestion as ‘‘bear-jams.’’ We investigated characteristics of bear-jams and their frequency relative to whitebark pine (Pinus albicaulis) cone production, an important fall food for bears, during 1990–2004. We observed a difference in diel distribution of bear-jams between species (x2=70.609, 4 df, Ptimes higher during poor cone crop years than good. We suggest that native foods found in road corridors may be especially important to some individual bears during years exhibiting poor whitebark pine crops. We discuss management implications of threats to whitebark pine and increasing habituation of bears to people.

  10. The importance of meat, particularly salmon, to body size, population productivity, and conservation of North American brown bears.

    Science.gov (United States)

    G.V. Hilderbrand; C.C. Schwartz; C.T. Robbins; M.E. Hanley Jacoby; S.M. Arthur; C. Servheen

    1999-01-01

    We hypothesized that the relative availability of meat, indicated by contribution to the diet, would be positively related to body size and population productivity of North American brown, or grizzly, bears (Ursus arctos). Dietary contributions of plant matter and meat derived from both terrestrial and marine sources were quantified by stable-...

  11. Modeling worldwide highway networks

    Science.gov (United States)

    Villas Boas, Paulino R.; Rodrigues, Francisco A.; da F. Costa, Luciano

    2009-12-01

    This Letter addresses the problem of modeling the highway systems of different countries by using complex networks formalism. More specifically, we compare two traditional geographical models with a modified geometrical network model where paths, rather than edges, are incorporated at each step between the origin and the destination vertices. Optimal configurations of parameters are obtained for each model and used for the comparison. The highway networks of Australia, Brazil, India, and Romania are considered and shown to be properly modeled by the modified geographical model.

  12. The Lincoln Highway in Utah

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This guidebook is on the Lincoln Highway in the state of Utah. Its purpose is to describe as closely as possible the original route of the Highway, the major changes...

  13. Highways: Interstate, US & State

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This dataset contains lines for all highways in the state of New Mexico. It is in a vector digital data structure digitized from a USGS 1:500,000 scale map of the...

  14. 硝酸腐蚀条件下公路桥梁氯丁橡胶支座抗剪试验%Shearing Tests of Plain Chloroprene Rubber Bearings of Highway Bridge under Acid Corrosion Condition

    Institute of Scientific and Technical Information of China (English)

    司月华; 王桂玲; 刘铭

    2015-01-01

    本研究将氯丁橡胶支座完全浸泡在pH为4.5的硝酸溶液中,对5组试件分别浸泡20d、40d、60d、80d、100d,将浸泡试件与标准件进行抗剪试验,将腐蚀试件与标准件的抗剪承载力、极限抗剪强度、水平等效刚度、抗剪弹性模量的数据进行对比分析,结果表明,氯丁橡胶支座在硝酸溶液浸泡后,其抗剪弹性阶段明显缩短,破坏程度更严重;从数据分析得,浸泡天数越多,其抗剪承载力、极限抗剪强度、抗剪弹性模量越小.%The neoprene bearings are completely soaked in nitric acid solution with pH=4.5, the five groups of speci-mens are soaked respectively for 20 d, 40 d, 60 d, 80 d, 80 d, thesoaked specimen andstandard partsare arried out with shear test.The data of shear bearing capacity,ultimate shear strength, equivalent stiffness and shear modulus of elasticity for the corrosion specimens are compared and analyzed with thoseof standard parts.The results show that af-ter soaking in nitric acid solution,neoprene bearing has significantly reduced shear elastic stage, and more serious damage. From the data analysis, it can be obtained that the more days it is soaked, itsshear bearing capacity, ultimate shear strength, shear elastic modulus become smaller .

  15. Reactor Pressure Vessel Integrity Assessments with the Grizzly Aging Simulation Code

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Benjamin; Backman, Marie; Hoffman, William; Chakraborty, Pritam

    2015-08-01

    Grizzly is a simulation tool being developed at Idaho National Laboratory (INL) as part of the US Department of Energy’s Light Water Reactor Sustainability program to provide improved safety assessments of systems, components, and structures in nuclear power plants subjected to age-related degradation. Its goal is to provide an improved scientific basis for decisions surrounding license renewal, which would permit operation of commercial nuclear power plants beyond 60 years. Grizzly is based on INL’s MOOSE framework, which enables multiphysics simulations in a parallel computing environment. It will address a wide variety of aging issues in nuclear power plant systems, components, and structures, modelling both the aging processes and the ability of age-degraded components to perform safely. The reactor pressure vessel (RPV) was chosen as the initial application for Grizzly. Grizzly solves tightly coupled equations of heat conduction and solid mechanics to simulate the global response of the RPV to accident conditions, and uses submodels to represent regions with pre-existing flaws. Domain integrals are used to calculate stress intensity factors on those flaws. A physically based empirical model is used to evaluate material embrittlement, and is used to evaluate whether crack growth would occur. Grizzly can represent the RPV in 2D or 3D, allowing it to evaluate effects that require higher dimensionality models to capture. Work is underway to use lower length scale models of material evolution to inform engineering models of embrittlement. This paper demonstrates an application of Grizzly to RPV failure assessment, and summarizes on-going work.

  16. Modeling multi-scale resource selection for bear rub trees in northwestern Montana

    Science.gov (United States)

    Morgan Henderson, Matthew J.; Hebblewhite, Mark; Mitchell, Michael S.; Stetz, Jeffrey B.; Kendall, Katherine C.; Carlson, Ross T.

    2015-01-01

    Both black (Ursus americanus) and grizzly bears (U. arctos) are known to rub on trees and other objects, producing a network of repeatedly used and identifiable rub sites. In 2012, we used a resource selection function to evaluate hypothesized relationships between locations of 887 bear rubs in northwestern Montana, USA, and elevation, slope angle, density of open roads and distance from areas of heightened plant-productivity likely containing forage for bears. Slope and density of open roads were negatively correlated with rub presence. No other covariates were supported as explanatory variables. We also hypothesized that bear rubs would be more strongly associated with closed roads and developed trails than with game trails. The frequencies of bear rubs on 30 paired segments of developed tracks and game trails were not different. Our results suggest bear rubs may be associated with bear travel routes, and support their use as “random” sampling devices for non-invasive spatial capture–recapture population monitoring.

  17. Highways of hope

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-08-15

    It is hoped that through public-private partnerships between Alpha Natural Resources and Pioneer Group and Virginia Department of Transportation, and between one of these coal companies and Buchanan County, Virginia, Industrial Development Authority a four-lane 'highway of hope' between Lovers Gap and Poplar Gap will be paved and a ridge top connector route will eventually be completed to Bull Gap where it will intersect with the Coalfields Expressway and US 460. The town of Grundy is also looking into strip mining coal from beneath the small mountaintop airport at Lovers Gap and turning it into a regional airport. The article discusses these plans. 4 photos.

  18. 75 FR 18014 - Federal Highway Administration

    Science.gov (United States)

    2010-04-08

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Highway Administration AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of...: Federal Highway Administration, Kentucky Division: Mr. Greg Rawlings, Transportation Specialist, 330...

  19. 78 FR 9771 - Federal Highway Administration

    Science.gov (United States)

    2013-02-11

    ... Federal Highway Administration Notice of Final Federal Agency Action on Proposed Transportation Project in Illinois and Indiana AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of limitation on..., Federal Highway Administration, 3250 Executive Park Drive, Springfield, Illinois 62703, Phone: (217)...

  20. 75 FR 14496 - Endangered and Threatened Wildlife and Plants; Reinstatement of Protections for the Grizzly Bear...

    Science.gov (United States)

    2010-03-26

    ... Convention on International Trade of Endangered Species of Wild Fauna and Flora (CITES). List of Subjects in 50 CFR Part 17 Endangered and threatened species, Exports, Imports, Reporting and recordkeeping... reinstating the regulatory protections under the Endangered Species Act of 1973 (ESA), as amended, for......

  1. DNA Fingerprinting to monitor grizzly bear populations in the Greater Glacier Area

    Science.gov (United States)

    Kendall, Katherine; Dave, Schirokauer; Peterson, Kris; Waits, Lisette P.

    2001-01-01

    A study area of 8,100 km² (2 million acres) was established where 126 8 x 8 km (64 km²) grid cells were identified for placement of traps. Trapping was carried out during five 2- week trap sessions. Some 620 hair traps were placed in the field; samples were retrieved between May 19th and August 12th, 1998. Approximately 7,200 hair samples were collected that year. Hair was found at 80% of the traps where the average number of hair samples per trap site was 14. Forty percent of the samples had 5 or more hair follicles. Preliminary results of sampling indicate that DNA was extracted from 90-100% of the hair samples (N=300). Eight hundred miles of trail were surveyed between June 1 and October 9. Thirteen hundred hair samples were collected from rub trees along trails. Seven hundred scat samples were collected from trails.

  2. Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment

    Science.gov (United States)

    Schwartz, Charles C.; Teisberg, Justin E.; Fortin, Jennifer K.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

    2014-01-01

    Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work combined a limited sample of hair, blood clots, and serum. Here we use a much larger sample to reassess those findings. We contrasted δ34S values in spring hair and serum with abundance of seeds of whitebark pine in samples collected from grizzly (Ursus arctos) and American black bears (U. americanus) in the GYE during 2000–2010. Although we found a positive relationship between δ34S values in spring hair and pine seed abundance for grizzly bears, the coefficients of determination were small (R2 ≤ 0.097); we failed to find a similar relationship with black bears. Values of δ34S in spring hair were larger in black bears and δ34S values in serum of grizzly bears were lowest in September and October, a time when we expect δ34S to peak if whitebark pine seeds were the sole source of high δ34S. The relationship between δ34S in bear tissue and the consumption of whitebark pine seeds, as originally reported, may not be as clean a method as proposed. Data we present here suggest other foods have high values of δ34S, and there is spatial heterogeneity affecting the δ34S values in whitebark pine, which must be addressed.

  3. Numerical simulation of highway fire transient space temperature field of bearing elements of long-span suspension bridge%大跨径悬索桥缆索承重构件公路火灾的瞬态空间温度场数值模拟

    Institute of Scientific and Technical Information of China (English)

    李利军; 万祥斌; 董晓明

    2015-01-01

    文章在国内外火灾研究工作的基础上,基于Ingason H平方增长模型,提出了适用于公路桥梁火灾研究的热释放率数学模型;根据建立的公路火灾物理模型,通过数值模拟给出公路火灾下悬索桥主缆、吊索表面温度及热流密度随火灾的发展过程而变化的规律公式,并建立了承重构件瞬态空间温度场。同一火灾场景下,不同直径的吊索可以采用相同的瞬态空间温度场;不同直径的主缆在不同位置具有相同的温度θt2时,可以采用相同的瞬态空间温度场。该研究成果可为今后大跨径悬索桥的抗火设计提供科学依据。%By reviewing and analyzing fire studies conducted at home and abroad ,and based on the Ingason H Square Growth Model ,several kinds of thermal release rate mathematical models are put forward ,which are suitable for the fire studies of highway bridges .Based on the established physical model of highway fire ,the trend of how the surface temperature and heat flux density of main and suspender cables of suspension bridge change with fire situation is observed through the numerical simulation .And the transient space temperature field of bearing elements is established .Under the same conditions of fire accident ,the same transient space temperature field can be applied to suspender cables with different diameters ;the same transient space temper‐ature field can be applied to main cables with different diameters when they have the same θt2 at different places .The research results can provide scientific basis for the fire resistance design of long‐span suspension bridge .

  4. Highway Performance Monitoring System (HPMS) (National)

    Data.gov (United States)

    Department of Transportation — The Federal Highway Administration (FHWA) has the responsibility to assure that adequate highway transportation information is available to support its functions and...

  5. Intelligent Lane Reservation System for Highway(s

    Directory of Open Access Journals (Sweden)

    Ciprian Dobre

    2012-01-01

    Full Text Available Highways tend to get congested because of the increase in the number of cars travelling on them. There are two solutions to this. The first one, which is also expensive, consists in building new highways to support the traffic. A much cheaper alternative consists in the introduction of advanced intelligent traffic control systems to manage traffic and increase the efficiency of the already existing highways. Intelligent lane reservation system for highways (ILRSH is such a software control system. It is designed to assist and automate the use of a highway lane as a reserved lane. The idea is to allow and support drivers to travel at a speed higher, if in return they are willing to pay a small fee to reserve an empty virtual slot on the reserved lane. This slot is valid for a portion and of the highway and a time window, so each driver pays the fee depending thier its travelling needs. In return, drivers are guaranteed a congestion-free travel on that portion. In this paper, we present the proposed architecture of the ILRSH and its subsystems. The system is based on several proposed algorithms designed to assist the drivers, enter or exit the reserved lane, based on real-world driving observations. We present extensive simulation results showing the feasibility of the proposed approach, that can easily be implemented with little costs on already-existing highways, and the increase in traffic efficiency.

  6. Scandinavian hydrogen highway partnership

    Energy Technology Data Exchange (ETDEWEB)

    Sloth, M.; Hansen, J. [H2 Logic A/S, Herning (Denmark); Wennike, F. [Hydrogen Link Denmark Association, Ringkoebing (Denmark)

    2009-07-01

    The Scandinavian Hydrogen Highway Partnership (SHHP) was launched in an effort to build hydrogen filling stations in Scandinavian countries by 2012 in order to enable hydrogen powered vehicles to operate and refuel when needed. Three hydrogen refueling stations are currently in operation in Scandinavia to fuel a fleet of 15 hydrogen-fuelled cars. It is anticipated that by the end of 2009, there will be 14 hydrogen refueling stations and more than 70 vehicles in operation. Beyond 2012, the number of filling stations and vehicles is expected to increase significantly through large scale demonstration, where SHHP aims to attract funding from the European Union. The current activities of SHHP are co-funded by national and regional authorities. The SHHP network is funded by Nordic Energy Research.

  7. Reactor Pressure Vessel Fracture Analysis Capabilities in Grizzly

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Backman, Marie [Univ. of Tennessee, Knoxville, TN (United States); Chakraborty, Pritam [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hoffman, William [Univ. of Idaho, Moscow, ID (United States)

    2015-03-01

    Efforts have been underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). Development in prior years has resulted a capability to calculate -integrals. For this application, these are used to calculate stress intensity factors for cracks to be used in deterministic linear elastic fracture mechanics (LEFM) assessments of fracture in degraded RPVs. The -integral can only be used to evaluate stress intensity factors for axis-aligned flaws because it can only be used to obtain the stress intensity factor for pure Mode I loading. Off-axis flaws will be subjected to mixed-mode loading. For this reason, work has continued to expand the set of fracture mechanics capabilities to permit it to evaluate off-axis flaws. This report documents the following work to enhance Grizzly’s engineering fracture mechanics capabilities for RPVs: • Interaction Integral and -stress: To obtain mixed-mode stress intensity factors, a capability to evaluate interaction integrals for 2D or 3D flaws has been developed. A -stress evaluation capability has been developed to evaluate the constraint at crack tips in 2D or 3D. Initial verification testing of these capabilities is documented here. • Benchmarking for axis-aligned flaws: Grizzly’s capabilities to evaluate stress intensity factors for axis-aligned flaws have been benchmarked against calculations for the same conditions in FAVOR. • Off-axis flaw demonstration: The newly-developed interaction integral capabilities are demon- strated in an application to calculate the mixed-mode stress intensity factors for off-axis flaws. • Other code enhancements: Other enhancements to the thermomechanics capabilities that relate to the solution of the engineering RPV fracture problem are documented here.

  8. Diet and Macronutrient Optimization in Wild Ursids: A Comparison of Grizzly Bears with Sympatric and Allopatric Black Bears

    National Research Council Canada - National Science Library

    Costello, Cecily M; Cain, Steven L; Pils, Shannon; Frattaroli, Leslie; Haroldson, Mark A; van Manen, Frank T

    2016-01-01

    ...% of digestible energy, relative to carbohydrates or lipids. In the wild, this ability is likely constrained by seasonal food availability, limits of intake rate as body size increases, and competition...

  9. Initial Probabilistic Evaluation of Reactor Pressure Vessel Fracture with Grizzly and Raven

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hoffman, William [Univ. of Idaho, Moscow, ID (United States); Sen, Sonat [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rabiti, Cristian [Idaho National Lab. (INL), Idaho Falls, ID (United States); Dickson, Terry [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bass, Richard [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-10-01

    The Grizzly code is being developed with the goal of creating a general tool that can be applied to study a variety of degradation mechanisms in nuclear power plant components. The first application of Grizzly has been to study fracture in embrittled reactor pressure vessels (RPVs). Grizzly can be used to model the thermal/mechanical response of an RPV under transient conditions that would be observed in a pressurized thermal shock (PTS) scenario. The global response of the vessel provides boundary conditions for local models of the material in the vicinity of a flaw. Fracture domain integrals are computed to obtain stress intensity factors, which can in turn be used to assess whether a fracture would initiate at a pre-existing flaw. These capabilities have been demonstrated previously. A typical RPV is likely to contain a large population of pre-existing flaws introduced during the manufacturing process. This flaw population is characterized stastistically through probability density functions of the flaw distributions. The use of probabilistic techniques is necessary to assess the likelihood of crack initiation during a transient event. This report documents initial work to perform probabilistic analysis of RPV fracture during a PTS event using a combination of the RAVEN risk analysis code and Grizzly. This work is limited in scope, considering only a single flaw with deterministic geometry, but with uncertainty introduced in the parameters that influence fracture toughness. These results are benchmarked against equivalent models run in the FAVOR code. When fully developed, the RAVEN/Grizzly methodology for modeling probabilistic fracture in RPVs will provide a general capability that can be used to consider a wider variety of vessel and flaw conditions that are difficult to consider with current tools. In addition, this will provide access to advanced probabilistic techniques provided by RAVEN, including adaptive sampling and parallelism, which can dramatically

  10. A Generalized Mathematical Model for the Fracture Problem of the Suspended Highway

    Directory of Open Access Journals (Sweden)

    Zhao Ying

    2017-01-01

    Full Text Available In order to answer dangling fracture problems of highway, the suspended pavement equivalent for non - suspended pavement, through the special boundary conditions has been suspended highway stress field of expression, in accordance with the 3D fracture model of crack formation, and establish a vacant, a general mathematics model for fracture problems of highway and analysis in highway suspended segment weight and vehicle load limit of highway capacity of Pu For overturning road inPu is less than the force of carrying more than compared to the work and fruit Bridge Hydropower Station Road engineering examples to verify suspended highway should force field expressions for the correctness and applicability. The results show that: when the hanging ratio R 0. 243177 limits of Pu design axle load 100kN. When the vertical crack in the vacant in the direction of length greater than 0. 1, the ultimate bearing capacity is less than the design axle load 100kN; when the hanging ratio R is less than 0. 5, the road to local fracture, the ultimate bearing capacity of suspended stress field expressions in solution; when the hanging ratio is greater than or equal to 0. 5, the road does not reach the limit bearing capacity of the whole body; torque shear surface of the effect is far less than the bending moments on shear planes.

  11. National Highway Planning Network (NHPN)

    Data.gov (United States)

    Department of Transportation — The NHPN (NTAD 2015) is a Geographical Information System (GIS) database that contains line features representing over 450,000 miles of current and planned highways...

  12. Highway Leasing and Club Theory

    OpenAIRE

    Huneke, William

    2009-01-01

    In recent years financially stressed jurisdictions have attempted to solve their fiscal shortfalls by leasing highways to private companies. The private company pays an upfront fee or promises a regular stream of cash payments in return for operating and collecting tolls from highway users during a fixed term. In a front page article on August 26, The Wall Street Journal described the efforts Pennsylvania was going through to lease the United States’ oldest, major toll road, the Pennsylvania ...

  13. Journal bearing

    Science.gov (United States)

    Menke, John R.; Boeker, Gilbert F.

    1976-05-11

    1. An improved journal bearing comprising in combination a non-rotatable cylindrical bearing member having a first bearing surface, a rotatable cylindrical bearing member having a confronting second bearing surface having a plurality of bearing elements, a source of lubricant adjacent said bearing elements for supplying lubricant thereto, each bearing element consisting of a pair of elongated relatively shallowly depressed surfaces lying in a cylindrical surface co-axial with the non-depressed surface and diverging from one another in the direction of rotation and obliquely arranged with respect to the axis of rotation of said rotatable member to cause a flow of lubricant longitudinally along said depressed surfaces from their distal ends toward their proximal ends as said bearing members are rotated relative to one another, each depressed surface subtending a radial angle of less than 360.degree., and means for rotating said rotatable bearing member to cause the lubricant to flow across and along said depressed surfaces, the flow of lubricant being impeded by the non-depressed portions of said second bearing surface to cause an increase in the lubricant pressure.

  14. Highway Safety Program Manual: Volume 12: Highway Design, Construction and Maintenance.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 12 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on highway design, construction and maintenance. The purpose and specific objectives of such a program are described. Federal authority in the area of highway safety and policies regarding…

  15. Highway Safety Program Manual: Volume 8: Alcohol in Relation to Highway Safety.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 8 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) concentrates on alcohol in relation to highway safety. The purpose and objectives of the alcohol program are outlined. Federal authority in the area of highway safety and general policies regarding…

  16. Highway Reaches Out to Chengtang

    Institute of Scientific and Technical Information of China (English)

    ZAIXIANGDONG

    2003-01-01

    Chengtang Town,tucked away on the Chinese border between the Xigaze area and Nepal,is known for high mountains and deep ravines,People there still live on slash and burn farming.Latest news is that a highway is being built to that part of the world.

  17. Highway Companies Deny Windfall Profits

    Institute of Scientific and Technical Information of China (English)

    Securities Daily

    2011-01-01

    @@ There is no denying that the real estate industry sees huge profits, but it is hard to imag-ine that the gross profits of highway companies have reached a very high level, becoming another typical industry of huge profits.The sky-high road toll is attracting more and more public concerns about the seemingly low-profile and stable industry.

  18. Highway runoff quality in Ireland.

    Science.gov (United States)

    Berhanu Desta, Mesfin; Bruen, Michael; Higgins, Neil; Johnston, Paul

    2007-04-01

    Highway runoff has been identified as a significant source of contaminants that impact on the receiving aquatic environment. Several studies have been completed documenting the characteristics of highway runoff and its implication to the receiving water in the UK and elsewhere. However, very little information is available for Ireland. The objective of this study was to determine the quality of highway runoff from major Irish roads under the current road drainage design and maintenance practice. Four sites were selected from the M4 and the M7 motorways outside Dublin. Automatic samplers and continuous monitoring devices were deployed to sample and monitor the runoff quality and quantity. More than 42 storm events were sampled and analysed for the heavy metals Cd, Cu, Pb, and Zn, 16 US EPA specified PAHs, volatile organic compounds including MTBE, and a number of conventional pollutants. All samples were analysed based on the Standard Methods. Significant quantities of solids and heavy metals were detected at all sites. PAHs were not detected very often, but when detected the values were different from quantities observed in UK highways. The heavy metal concentrations were strongly related to the total suspended solids concentrations, which has a useful implication for runoff management strategies. No strong relationship was discovered between pollutant concentrations and event characteristics such as rainfall intensity, antecedent dry days (ADD), or rainfall depth (volume). This study has demonstrated that runoff from Irish motorways was not any cleaner than in the UK although the traffic volume at the monitored sites was relatively smaller. This calls for a site specific investigation of highway runoff quality before adopting a given management strategy.

  19. Wildlife crossings toolkit

    OpenAIRE

    2005-01-01

    Many highways wind their way through excellent wildlife habitat. Florida’s highways slice through rare black bear habitat. Alaska struggles with moose-vehicle collisions. Grizzly bears in the northern Rockies are killed on highways or avoid crossing them, limiting them to smaller areas. Solutions are available, but the information is widely scattered. The Wildlife Crossings Toolkit gathers information in one location on proven solutions and lessons learned. Who can use the toolkit? Profession...

  20. Gene flow between insular, coastal and interior populations of brown bears in Alaska.

    Science.gov (United States)

    Paetkau, D; Shields, G F; Strobeck, C

    1998-10-01

    The brown bears of coastal Alaska have been recently regarded as comprising from one to three distinct genetic groups. We sampled brown bears from each of the regions for which hypotheses of genetic uniqueness have been made, including the bears of the Kodiak Archipelago and the bears of Admiralty, Baranof and Chichagof (ABC) Islands in southeast Alaska. These samples were analysed with a suite of nuclear microsatellite markers. The 'big brown bears' of coastal Alaska were found to be part of the continuous continental distribution of brown bears, and not genetically isolated from the physically smaller 'grizzly bears' of the interior. By contrast, Kodiak brown bears appear to have experienced little or no genetic exchange with continental populations in recent generations. The bears of the ABC Islands, which have previously been shown to undergo little or no female-mediated gene flow with mainland populations, were found not to be genetically isolated from mainland bears. The data from the four insular populations indicate that female and male dispersal can be reduced or eliminated by water barriers of 2-4 km and 7 km in width, respectively.

  1. Fracture Capabilities in Grizzly with the extended Finite Element Method (X-FEM)

    Energy Technology Data Exchange (ETDEWEB)

    Dolbow, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Ziyu [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Jiang, Wen [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    Efforts are underway to develop fracture mechanics capabilities in the Grizzly code to enable it to be used to perform deterministic fracture assessments of degraded reactor pressure vessels (RPVs). A capability was previously developed to calculate three-dimensional interaction- integrals to extract mixed-mode stress-intensity factors. This capability requires the use of a finite element mesh that conforms to the crack geometry. The eXtended Finite Element Method (X-FEM) provides a means to represent a crack geometry without explicitly fitting the finite element mesh to it. This is effected by enhancing the element kinematics to represent jump discontinuities at arbitrary locations inside of the element, as well as the incorporation of asymptotic near-tip fields to better capture crack singularities. In this work, use of only the discontinuous enrichment functions was examined to see how accurate stress intensity factors could still be calculated. This report documents the following work to enhance Grizzly’s engineering fracture capabilities by introducing arbitrary jump discontinuities for prescribed crack geometries; X-FEM Mesh Cutting in 3D: to enhance the kinematics of elements that are intersected by arbitrary crack geometries, a mesh cutting algorithm was implemented in Grizzly. The algorithm introduces new virtual nodes and creates partial elements, and then creates a new mesh connectivity; Interaction Integral Modifications: the existing code for evaluating the interaction integral in Grizzly was based on the assumption of a mesh that was fitted to the crack geometry. Modifications were made to allow for the possibility of a crack front that passes arbitrarily through the mesh; and Benchmarking for 3D Fracture: the new capabilities were benchmarked against mixed-mode three-dimensional fracture problems with known analytical solutions.

  2. Magnetic Bearing

    Science.gov (United States)

    1996-01-01

    AVCON, Inc. produces advanced magnetic bearing systems for industrial use, offering a unique technological approach based on contract work done at Marshall Space Flight Center and Lewis Research Center. Designed for the turbopump of the Space Shuttle main engine, they are now used in applications such as electric power generation, petroleum refining, machine tool operation and natural gas pipelines. Magnetic bearings support moving machinery without physical contact; AVCON's homopolar approach is a hybrid of permanent and electromagnets which are one-third the weight, smaller and more power- efficient than previous magnetic bearings.

  3. Lead Isotopes in Highway Runoff

    Science.gov (United States)

    Ferreira, M.; Lau, S.; Green, P. G.; Stenstrom, M. K.

    2011-12-01

    Lead (Pb) isotopes have been used extensively to study the provenance of lead pollution on air, water, and sediments. In this study, we measured Pb isotopes and Pb aqueous concentration in highway runoff in three west Los Angeles sites. Those three sites, part of a long-term study sponsored by the California Department of Transportation, represent small catchment areas, and host heavy traffic. In addition, there were no inputs of sand or salt to the highway because the sites are almost completely impervious and also due to the lack of snow to be controlled. Highway runoff from the three sites was collected for 7 storms during the 2004-2005 Winter. Grab samples were collected every 15 minutes during the first hour, and hourly afterwards. A total of 202 samples were collected and filtered into five size fractions (100μm). Aqueous concentration of Pb range from 0.08μg/L to 46.95μg/L (7.98±10.89μg/L) and it is not correlated with any of the lead isotope ratios. The 208Pb/206Pb ratio ranges from 1.983 to 2.075 (2.024±0.026) and there is no statistical difference for the mean value of the 208Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). However, the 208Pb/206Pb ratio of nearby soils yield 2.060±0.021 and it is statistically different from the ratios obtained for the highway runoff. This hints that the lead present in highway runoff does not come from local soils. The 207Pb/206Pb ratio ranges from 0.804 to 0.847 (0.827±0.011) and there is no statistical difference for the mean value of the 207Pb/206Pb ratio for the four particulate size fractions (0.45-8μm, 8-20μm, 20-100μm, >100μm). Surprisingly, there is also no statistical difference with the 207Pb/206Pb ratio of nearby soils (0.833±0.009).

  4. Foil bearings

    Science.gov (United States)

    Elrod, David A.

    1993-01-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  5. Foil bearings

    Science.gov (United States)

    Elrod, David A.

    1993-11-01

    The rolling element bearings (REB's) which support many turbomachinery rotors offer high load capacity, low power requirements, and durability. Two disadvantages of REB's are: (1) rolling or sliding contact within the bearing has life-limiting consequences; and (2) REB's provide essentially no damping. The REB's in the Space Shuttle Main Engine (SSME) turbopumps must sustain high static and dynamic loads, at high speeds, with a cryogenic fluid as lubricant and coolant. The pump end ball bearings limit the life of the SSME high pressure oxygen turbopump (HPOTP). Compliant foil bearing (CFB) manufacturers have proposed replacing turbopump REB's with CFB's CFB's work well in aircraft air cycle machines, auxiliary power units, and refrigeration compressors. In a CFB, the rotor only contracts the foil support structure during start up and shut down. CFB damping is higher than REB damping. However, the load capacity of the CFB is low, compared to a REB. Furthermore, little stiffness and damping data exists for the CFB. A rotordynamic analysis for turbomachinery critical speeds and stability requires the input of bearing stiffness and damping coefficients. The two basic types of CFB are the tension-dominated bearing and the bending-dominated bearing. Many investigators have analyzed and measured characteristics of tension-dominated foil bearings, which are applied principally in magnetic tape recording. The bending-dominated CFB is used more in rotating machinery. This report describes the first phase of a structural analysis of a bending-dominated, multileaf CFB. A brief discussion of CFB literature is followed by a description and results of the present analysis.

  6. Residential satisfaction close to highways : The impact of accessibility, nuisances and highway adjustment projects

    NARCIS (Netherlands)

    Hamersma, Marije; Tillema, Taede; Sussman, Joseph; Arts, Jos

    In this paper we focus on gaining insight into the residential satisfaction of households near highways, based on survey data collected among 1225 respondents in the Netherlands living within 1000 m from a highway. Ordinal regression was used to study the impact of highway externalities on

  7. Residential satisfaction close to highways : The impact of accessibility, nuisances and highway adjustment projects

    NARCIS (Netherlands)

    Hamersma, Marije; Tillema, Taede; Sussman, Joseph; Arts, Jos

    2014-01-01

    In this paper we focus on gaining insight into the residential satisfaction of households near highways, based on survey data collected among 1225 respondents in the Netherlands living within 1000 m from a highway. Ordinal regression was used to study the impact of highway externalities on residenti

  8. Pollution transport from a highway

    Energy Technology Data Exchange (ETDEWEB)

    Lygren, E.; Gjessing, E.; Berglind, L.

    1984-02-15

    In Norway a considerable amount of pavement dust is produced during a year, particularly during the winter season when studded tires are used on vehicles. The asphalt wear when using tires is estimated to be 20-50 g/km/vehicle. This matter will partly be deposited on the road surface and partly be transported through the atmosphere to the surrounding area together with other motor traffic pollutants. A 3 year programme, sponsored by the Norwegian Road Directorate, was aimed also at characterizing the nature and the fate of the particulate matter from a highway. The characterization included studies on particle-size distribution, heavy metal concentration and contents of organic micropollutants, such as PAH. It was found that a major part of the pollutants from a highway was deposited 5-25 m from the road. Further it was observed that an essential part of the pollutants were 'produced' through the snow accumulation period and released during the spring period. The period of snowmelt thus gave the most important effects on the surface water. (A.V.)

  9. Ice Control with Brine on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars

    During the years 1996-2006, the Division of Highways and Transportation in the former county of Funen gradually replaced pre-wetted salt with brine as de-icing agent in all her ice control activities. The replacement related to 1000 kilometres of highways. Jeopardizing neither road safety nor...

  10. Engineering geology as applied to highway construction

    Science.gov (United States)

    Gard, Leonard M.

    1955-01-01

    A geologic study of the site for a relocated segment of State Highway 93 northwest of Denver Colo., was made by by the Engineering Geology Branch of the U.S. Geological Survey as a demonstration of the applicability of geologic mapping to problems of highway construction. The relocated segment provides access to the Rocky Flats plant of the Atomic Energy Commission.  

  11. A Study on Supply Model of Rural Highways in China

    Directory of Open Access Journals (Sweden)

    Wang Dexiang

    2015-01-01

    Full Text Available Rural highway has a significant impact to build a moderately prosperous society in all aspects, and it is an important critical infrastructure to build harmonious society. Highway has its own economics attributes, and rural highway also has its own characteristics. This paper combines with rural highway characteristics to analyze the supply model and problems of rural highway. It summarizes several mixed supply models of rural highways.

  12. Induced Polarization Surveying for Acid Rock Screening in Highway Design

    Science.gov (United States)

    Butler, K. E.; Al, T.; Bishop, T.

    2004-05-01

    Highway and pipeline construction agencies have become increasingly vigilant in their efforts to avoid cutting through sulphide-bearing bedrock that has potential to produce acid rock drainage. Blasting and fragmentation of such rock increases the surface area available for sulphide oxidation and hence increases the risk of acid rock drainage unless the rock contains enough natural buffering capacity to neutralize the pH. In December, 2001, the New Brunswick Department of Transportation (NBOT) sponsored a field trial of geophysical surveying in order to assess its suitability as a screening tool for locating near-surface sulphides along proposed highway alignments. The goal was to develop a protocol that would allow existing programs of drilling and geochemical testing to be targeted more effectively, and provide design engineers with the information needed to reduce rock cuts where necessary and dispose of blasted material in a responsible fashion. Induced polarization (IP) was chosen as the primary geophysical method given its ability to detect low-grade disseminated mineralization. The survey was conducted in dipole-dipole mode using an exploration-style time domain IP system, dipoles 8 to 25 m in length, and six potential dipoles for each current dipole location (i.e. n = 1 - 6). Supplementary information was provided by resistivity and VLF-EM surveys sensitive to lateral changes in electrical conductivity, and by magnetic field surveying chosen for its sensitivity to the magnetic susceptibility of pyrrhotite. Geological and geochemical analyses of samples taken from several IP anomalies located along 4.3 line-km of proposed highway confirmed the effectiveness of the screening technique. IP pseudosections from a region of metamorphosed shales and volcaniclastic rocks identified discrete, well-defined mineralized zones. Stronger, overlapping, and more laterally extensive IP anomalies were observed over a section of graphitic and sulphide-bearing metasedimentary

  13. Alaska Highway bibliography, 3rd edition

    DEFF Research Database (Denmark)

    Prange, Laurie

    . The military need for the Alaska Highway and Canol pipeline declined at the end of World War II. In 1946, Canada officially accepted responsibility for maintaining and developing the Yukon portion of the Alaska Highway. The Alaska Highway affected both First Nations and non-First Nations peoples immediately...... the 1920s and 1930s a small but vocal group of “builders” began to campaign for a highway, either a coastal or inland route, to improve the northwest’s economic base. With the impending threat of war in the late 1930s, there was an increasing awareness by the American and Canadian governments....... The impacts included an increased awareness of the world outside of the Yukon, imported ideas and technology, improved health care, highway transportation, telecommunications, and the development of more mining and tourist-related industries....

  14. Computational Intelligence in Highway Management: A Review

    Directory of Open Access Journals (Sweden)

    Ondrej Pribyl

    2015-10-01

    Full Text Available Highway management systems are used to improve safety and driving comfort on highways by using control strategies and providing information and warnings to drivers. They use several strategies starting from speed and lane management, through incident detection and warning systems, ramp metering, weather information up to, for example, informing drivers about alternative roads. This paper provides a review of the existing approaches to highway management systems, particularly speed harmonization and ramp metering. It is focused only on modern and advanced approaches, such as soft computing, multi-agent methods and their interconnection. Its objective is to provide guidance in the wide field of highway management and to point out the most relevant recent activities which demonstrate that development in the field of highway management is still important and that the existing research exhibits potential for further enhancement.

  15. Hydrodynamic bearings

    CERN Document Server

    Bonneau, Dominique; Souchet, Dominique

    2014-01-01

    This Series provides the necessary elements to the development and validation of numerical prediction models for hydrodynamic bearings. This book describes the rheological models and the equations of lubrication. It also presents the numerical approaches used to solve the above equations by finite differences, finite volumes and finite elements methods.

  16. Monitoring and mitigating measures to reduce potential impacts of oil and gas exploration and development on bears in the Inuvik region

    Energy Technology Data Exchange (ETDEWEB)

    Branigan, M. [Government of the Northwest Territories, Inuvik, NT (Canada). Dept. of Environment and Natural Resources

    2007-07-01

    The Inuvik Region consists of the Northwest Territories portion of the Inuvialuit Settlement Region and the Gwich'in Settlement Area. The range of grizzly bears, polar bears and black bears extends to different parts of the region. The potential impact of development depends on the season of the development and the species of bear found in the footprint. As such, monitoring and mitigation measures should take this into consideration. This presentation focused on the potential impacts and current practices to monitor and mitigate the impacts in the region. Mitigation measures currently used include: communication with stakeholders; waste management guidelines; use of wildlife monitors to identify key habitat and den sites and to deter bears; minimum flight altitudes; and safety training. Suggestions for additional mitigation measures were also presented. figs.

  17. HOV on the information highway

    Science.gov (United States)

    Carlowicz, Michael

    Sick of rush-hour traffic jams? Tired of bottlenecks that keep you from getting where you want to go? Frustrated by sluggish drivers who tie you up on your way to work? The National Science Foundation (NSF) is hoping to put scientists back in the fast lane—of the Internet, that is.The recent boom in the popularity of the Internet has brought traffic on some parts of the information highway to a crawl. Since all packets of information sent across the Internet are treated equally, e-mail love letters and playful web browsing can interfere with scientific data transfers and high-performance on-line experiments and conferences.

  18. State Maintained Highways in Louisiana, UTM Zone 15 NAD83, LDOTD (2007) [state_highways_ldotd_2007

    Data.gov (United States)

    Louisiana Geographic Information Center — This dataset represents the state maintained road network of Louisiana. The dataset includes Interstates, US highways, and Louisiana State Highways. This dataset was...

  19. Highway Safety Program Manual: Volume 13: Traffic Engineering Services.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 13 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on traffic engineering services. The introduction outlines the purposes and objectives of Highway Safety Program Standard 13 and the Highway Safety Program Manual. Program development and…

  20. 75 FR 18095 - America's Marine Highway Program

    Science.gov (United States)

    2010-04-09

    ... Department of Transportation receive funding to execute the research component of the program in order to... Marine Highway under this program. In crafting this definition, the Department of Transportation was...

  1. Transition curves for highway geometric design

    CERN Document Server

    Kobryń, Andrzej

    2017-01-01

    This book provides concise descriptions of the various solutions of transition curves, which can be used in geometric design of roads and highways. It presents mathematical methods and curvature functions for defining transition curves. .

  2. Highway travel time estimation with data fusion

    CERN Document Server

    Soriguera Martí, Francesc

    2016-01-01

    This monograph presents a simple, innovative approach for the measurement and short-term prediction of highway travel times based on the fusion of inductive loop detector and toll ticket data. The methodology is generic and not technologically captive, allowing it to be easily generalized for other equivalent types of data. The book shows how Bayesian analysis can be used to obtain fused estimates that are more reliable than the original inputs, overcoming some of the drawbacks of travel-time estimations based on unique data sources. The developed methodology adds value and obtains the maximum (in terms of travel time estimation) from the available data, without recurrent and costly requirements for additional data. The application of the algorithms to empirical testing in the AP-7 toll highway in Barcelona proves that it is possible to develop an accurate real-time, travel-time information system on closed-toll highways with the existing surveillance equipment, suggesting that highway operators might provide...

  3. Geometric Design of Highways in USA

    Directory of Open Access Journals (Sweden)

    Hrvoje Baričević

    2012-10-01

    Full Text Available This paper describes the criteria, standards, and engineeringprocedures used to design principal elements of the highwayalignment, highway cross sections, and adjacent roadside environment.Development of a comprehensive highway design focuseson the establishment of travel lane configuration, alignmentlocation, and all dimensions related to the highway crosssection. A three-dimensional physical location is determinedthrough calculation of a horizontal and vertical alignment ofthe highway centerline, based on a variety of operational considerations.The results of these activities are refe"ed to as thegeometric design and represent all the visible features of a highwayor street. The first and major portion of the paper deals withthe design of motor-vehicle facilities. Specific design elementsare described and discussed with respect to design methodology.

  4. 2004 Alaska highway invasive plants pilot survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We investigated the distribution and abundance of non-native invasive plants along a section of the Alaska Highway adjacent to Tetlin National Wildlife Refuge, 20...

  5. Stories About Highways in Tibet (Ⅲ)

    Institute of Scientific and Technical Information of China (English)

    BENGYI

    2005-01-01

    After the Xikang-Tibet Highway and the Qinghai-Tibet Highway were opened to traffic, other highways were constructed including the Xinjiang-Tibet Highway extending from Yecheng in Xinjiang to Ngari in Tibet, the Lhasa-Yadong Highway, the Lhasa-Zetang Highway, the Xigaze-Tingri Highway and the Heihe-Qamdo Highway. Sand and stone may only have covered these roads,but they were an embryonic form of modem transportation in Tibet and served as a solid foundation for development of modem highways. Until 1959, before the Democratic Reform in Tibet, the overall length of highways totaled 5,648 kilometers, creating a primary Tibetan road network with Lhasa as the center.

  6. Sustainable Waste Management for Green Highway Initiatives

    Directory of Open Access Journals (Sweden)

    Husin Nur Illiana

    2016-01-01

    Full Text Available Green highway initiative is the transportation corridors based on sustainable concept of roadway. It incorporates both transportation functionality and ecological requirements. Green highway also provides more sustainable construction technique that maximizes the lifespan of highway. Waste management is one of the sustainable criterias in the elements of green highway. Construction of highway consumes enormous amounts of waste in term of materials and energy. These wastes need to be reduce to sustain the environment. This paper aims to identify the types of waste produced from highway construction. Additionally, this study also determine the waste minimization strategy and waste management practiced.. This study main focus are construction and demolition waste only. The methodology process begin with data collection by using questionnaire survey. 22 concession companies listed under Lembaga Lebuhraya Malaysia acted as a respondent. The questionnaires were distributed to all technical department staffs. The data received was analyzed using IBM SPSS. The results shows the most production of waste is wood, soil, tree root and concrete. The least production of waste is metal. For waste minimization, the best waste minimization is reuse for all type of waste except for tree root and stump. Whereas, the best waste management is providing strategic plan. The least practice for waste management is recording the quantity of waste.

  7. Light Water Reactor Sustainability Program Grizzly Year-End Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin Spencer; Yongfeng Zhang; Pritam Chakraborty; S. Bulent Biner; Marie Backman; Brian Wirth; Stephen Novascone; Jason Hales

    2013-09-01

    The Grizzly software application is being developed under the Light Water Reactor Sustainability (LWRS) program to address aging and material degradation issues that could potentially become an obstacle to life extension of nuclear power plants beyond 60 years of operation. Grizzly is based on INL’s MOOSE multiphysics simulation environment, and can simultaneously solve a variety of tightly coupled physics equations, and is thus a very powerful and flexible tool with a wide range of potential applications. Grizzly, the development of which was begun during fiscal year (FY) 2012, is intended to address degradation in a variety of critical structures. The reactor pressure vessel (RPV) was chosen for an initial application of this software. Because it fulfills the critical roles of housing the reactor core and providing a barrier to the release of coolant, the RPV is clearly one of the most safety-critical components of a nuclear power plant. In addition, because of its cost, size and location in the plant, replacement of this component would be prohibitively expensive, so failure of the RPV to meet acceptance criteria would likely result in the shutting down of a nuclear power plant. The current practice used to perform engineering evaluations of the susceptibility of RPVs to fracture is to use the ASME Master Fracture Toughness Curve (ASME Code Case N-631 Section III). This is used in conjunction with empirically based models that describe the evolution of this curve due to embrittlement in terms of a transition temperature shift. These models are based on an extensive database of surveillance coupons that have been irradiated in operating nuclear power plants, but this data is limited to the lifetime of the current reactor fleet. This is an important limitation when considering life extension beyond 60 years. The currently available data cannot be extrapolated with confidence further out in time because there is a potential for additional damage mechanisms (i

  8. 76 FR 1664 - Notice of Final Federal Agency Actions on State Highway 99 (Segment G)

    Science.gov (United States)

    2011-01-11

    ... Federal Highway Administration Notice of Final Federal Agency Actions on State Highway 99 (Segment G... relate to a proposed highway project, Grand Parkway (State Highway 99) Segment G, from Interstate Highway... the following highway project in the State of Texas: Grand Parkway (State Highway 99) Segment G from...

  9. Highway Surveying. Instructor's Guide for an Adult Course. Highway Technicians Program Unit III.

    Science.gov (United States)

    Fimmano, Ralph; Kacharian, John C.

    The revised instructor's guide, which is part of the New York State Highway Technician's Program to provide needed technicians and engineers by upgrading people in the lower-level technician jobs, is geared toward the improvement of technical skills and knowledge in highway surveying. In view of the shortage of qualified technicians and engineers…

  10. Market definition studies for photovoltaic highway applications

    Science.gov (United States)

    1978-01-01

    Prospects for solar electric power in applications related to highways within the continental United States are examined. Principal prospective users are found to be the highway departments of the various states. Economic analysis is employed to demonstrate that suitable applications can occur when powering apparatus such as signs, crossing signals, or instruments which consume less than 100 watts on the average, provided they are located at least one-half mile from existing utility power. Such applications are projected to occur two or three times per state per year. Attitudes of highway officials toward possible use of solar power are sampled and described. Although falling photovoltaic cell prices are expected to have little effect on sales potential here, methods for federal stimulation of this market are discussed.

  11. Comparative analysis of fecal microbiota and intestinal microbial metabolic activity in captive polar bears.

    Science.gov (United States)

    Schwab, Clarissa; Gänzle, Michael

    2011-03-01

    The composition of the intestinal microbiota depends on gut physiology and diet. Ursidae possess a simple gastrointestinal system composed of a stomach, small intestine, and indistinct hindgut. This study determined the composition and stability of fecal microbiota of 3 captive polar bears by group-specific quantitative PCR and PCR-DGGE (denaturing gradient gel electrophoresis) using the 16S rRNA gene as target. Intestinal metabolic activity was determined by analysis of short-chain fatty acids in feces. For comparison, other Carnivora and mammals were included in this study. Total bacterial abundance was approximately log 8.5 DNA gene copies·(g feces)-1 in all 3 polar bears. Fecal polar bear microbiota was dominated by the facultative anaerobes Enterobacteriaceae and enterococci, and the Clostridium cluster I. The detection of the Clostridium perfringens α-toxin gene verified the presence of C. perfringens. Composition of the fecal bacterial population was stable on a genus level; according to results obtained by PCR-DGGE, dominant bacterial species fluctuated. The total short-chain fatty acid content of Carnivora and other mammals analysed was comparable; lactate was detected in feces of all carnivora but present only in trace amounts in other mammals. In comparison, the fecal microbiota and metabolic activity of captive polar bears mostly resembled the closely related grizzly and black bears.

  12. Highway Capacity Loss Induced by Rainfall

    Directory of Open Access Journals (Sweden)

    Hashim Mohammed Alhassan

    2011-01-01

    Full Text Available The effect of rainfall on capacity reduction on highways has been investigated. Traffic data was generated for both wet and dry conditions. The data analysis showed that the highway section studied was operating in free flow region. A 2.7% capacity loss was obtained for the road. It is argued that no traffic instability could arise from this situation if the state of traffic remains in the free flow regime. However, in the event of the coincidence of fixed bottlenecks and rainfall, instabilities arising from that could lead to further capacity loss.

  13. Seismic fragility of a highway bridge in Quebec retrofitted with natural rubber isolators

    Directory of Open Access Journals (Sweden)

    G. H. Siqueira

    Full Text Available This paper presents fragility curves for the evaluation of a highway bridge retrofitted with seismic isolator devices. The object of this study is the Chemin des Dalles bridge over Highway 55 located in Trois-Rivières in Quebec, Canada. A series of synthetic ground motions time histories compatible with eastern Canada are used to capture the uncertainties related to the hazard. The seismic isolator model represents natural rubber bearing placed under the longitudinal girders over the bents and the abutments of the bridge. NRB isolators are placed in these locations to uncouple the movement of the superstructure and the infrastructure, increasing the flexibility of the system and decreasing the forces transmitted to the infrastructure. Finally, a set of fragility curves for the as-built and retrofitted models are compared to evaluate the effectiveness of seismic isolation to decrease the seismic vulnerability of this bridge.

  14. Stories About Highways in Tibet (Ⅳ)

    Institute of Scientific and Technical Information of China (English)

    BENGYI

    2005-01-01

    Tibet's First International Highway The China-Nepal Highway is Tibet's only international highway. It extends 1,036 krn from Lhasa to Kathmandu, capital of Nepal. The Tibetan section extends 827 km. Construction of the highway lasted 10 years. Between March 1951 and October 20, 1955, the Lhasa-Xigaze Highway was constructed, bringing to an end a history of the Xigaze region possessing no proper roads. In 1955 the 90-km Xigaze-Gyangze section was constructed, being opened to traffic in October 1955. In 1956, the Lhasa-Yadong Highway was constructed, extending 547 km. In 1958, the Xigaze-Tingri Highway was completed, followed in 1960 by the Lhasa-Burang Highway.

  15. 78 FR 53497 - Uniform Procedures for State Highway Safety Grant Programs

    Science.gov (United States)

    2013-08-29

    ... National Highway Traffic Safety Administration Uniform Procedures for State Highway Safety Grant Programs AGENCY: National Highway Traffic Safety Administration, DOT. ACTION: Request for public comment on..., National Highway Traffic Safety Administration, Office of Regional Operations and Program...

  16. OML-Highway within the framework of SELMAGIS. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.; Becker, T.; Ketzel, M.; Loefstroem, P.; Roerdam Olesen, H. (Aarhus Univ., National Environmental Research Institute, Dept. of Atmospheric Environment (Denmark)); Lorentz, H. (Ingenieurbuero Lohmeyer (Germany))

    2010-06-15

    This report describes the OML-Highway model and its integration into SELMAGIS. The National Environmental Research Institute (NERI) has developed the OML-Highway model and Ingenieurbuero Lohmeyer from Germany has developed SELMAGIS. The OML-Highway model is able to calculate air pollution concentration levels at receptor points along a highway road network, while SELMAGIS is a framework for calculating and representing air pollutant emissions and concentrations in a geographical information system (GIS). (author)

  17. OML-Highway within the framework of SELMAGIS. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Solvang Jensen, S.; Becker, T.; Ketzel, M.; Loefstroem, P.; Roerdam Olesen, H. (Aarhus Univ., National Environmental Research Institute, Dept. of Atmospheric Environment (Denmark)); Lorentz, H. (Ingenieurbuero Lohmeyer (Germany))

    2010-06-15

    This report describes the OML-Highway model and its integration into SELMAGIS. The National Environmental Research Institute (NERI) has developed the OML-Highway model and Ingenieurbuero Lohmeyer from Germany has developed SELMAGIS. The OML-Highway model is able to calculate air pollution concentration levels at receptor points along a highway road network, while SELMAGIS is a framework for calculating and representing air pollutant emissions and concentrations in a geographical information system (GIS). (author)

  18. 76 FR 6690 - Highway Systems; Technical Correction

    Science.gov (United States)

    2011-02-08

    .... FOR FURTHER INFORMATION CONTACT: Stefan Natzke, National Systems and Economic Development Team, (202... document can be used to cross reference this action with the Unified Agenda. List of Subjects in 23 CFR...)(1), and footnote 1 to read as follows: Sec. 470.105 Urban area boundaries and highway functional...

  19. Heavy Vehicles on Minor Highway Bridges

    DEFF Research Database (Denmark)

    Kirkegaard, Poul Henning; Nielsen, Søren R. K.; Enevoldsen, I.

    the results obtained using the numerical models given in details in "Heavy Vehicles on Minor Highway Bridges : dynamic modelling of vehicles and bridges". The models are established using a ordinary vehicle which consists of a 48 t Scania with a 3 axle tractor and a 3 axle trailer, joined in a flexible hinge...

  20. Highway Traffic Safety Manpower Functions Guide.

    Science.gov (United States)

    Daugherty, Ronald D.; And Others

    The purpose of the project, "Revision and Update of Traffic Safety Manpower Training Program Development Guide," was to develop the HIGHWAY TRAFFIC SAFETY MANPOWER FUNCTIONS GUIDE. This document provides an organizational schema illustrating the functions essential to be performed and the interrelationship of these functions to carry out…

  1. Traffic Flow Control In Automated Highway Systems

    OpenAIRE

    Alvarez, Luis; Horowitz, Roberto

    1997-01-01

    This report studies the problem of traffic control in the Automated Highway System (AHS) hierarchical architecture of the California PATH program. A link layer controller for the PATH AHS architecture is presented. It is shown that the proposed control laws stabilize the vehicular density and flow around predetermined profiles.

  2. 77 FR 37093 - Amendments to Highway Safety Program Guidelines

    Science.gov (United States)

    2012-06-20

    ..., Guideline No. 6 Codes and Laws, Guideline No. 16 Management of Highway Incidents (formerly Debris Hazard... activities statewide. Highway Safety Program Guideline No. 16 Management of Highway Incidents (Formerly... program should provide at a minimum that: A. Traffic Incident Management programs are effective and...

  3. Explaining residential moving intentions : the case of highway locations

    NARCIS (Netherlands)

    Hamersma, Marije; Heinen, Eva; Tillema, Taede; Arts, Jos

    2013-01-01

    In this paper Structural Equation Modeling is used to test a theoretical framework to explain the impact of highway externalities (i.e. accessibility and nuisance) on moving intentions of people living close to highways. We aimed to study whether highway externalities (alongside other contextual fac

  4. Policy Safeguards and the Legitimacy of Highway Interdiction

    Science.gov (United States)

    2016-12-01

    strategy of highway interdiction, such as complaints of police misconduct or the public’s perception of unfair law enforcement practices. The...communities continue to express concerns associated with unfair treatment and exposure to police misconduct. The frustration of the minority community about...highway interdiction operations were reviewed by a supervisor with highway interdiction experience. This review is a distinctive advantage for

  5. Highway Safety Program Manual: Volume 15: Police Traffic Services.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 15 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on police traffic services. The purpose and objectives of a police services program are described. Federal authority in the areas of highway safety and policies regarding a police traffic…

  6. Highway Safety Program Manual: Volume 10: Traffic Records.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 10 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on traffic records. The purpose and specific objectives of a traffic records program are discussed. Federal authority in the area of highway safety and policies regarding a traffic records…

  7. Eco-Heroes out of Place and Relations: Decolonizing the Narratives of "Into the Wild" and "Grizzly Man" through Land Education

    Science.gov (United States)

    Korteweg, Lisa; Oakley, Jan

    2014-01-01

    Eco-heroic quests for environmental communion continue to be represented, mediated, and glorified through film and media narratives. This paper examines two eco-heroic quests in the Alaskan "wilderness" that have been portrayed in two Hollywood motion pictures: the movies "Grizzly Man" and "Into the Wild". Both films…

  8. US Highway 395 Widen Median and Shoulder and Install Rumble Strips Project Environmental Assessment, Edwards Air Force Base, California

    Science.gov (United States)

    2015-12-16

    steel highway structures, moving engine parts Copper Metal plating, bearing and bushing wear, moving engine parts, brake lining wear, fungicide and...entire bridge structure and its pillars and guardrails with a new bridge; pillar removal requires excavation. Temporary access roads may be needed to...Mojave Chevron Lucerne Valley 516 10 Western Mojave Nevada Solar One - NV 400 ** Northeastern Mojave Copper Mountain North - NV 1,400 30

  9. OML-Highway within the framework of SELMAGIS

    DEFF Research Database (Denmark)

    Jensen, Steen Solvang; Becker, Thomas; Ketzel, Matthias;

    This report describes the OML-Highway model and its integration into SELMAGIS. The National Environmental Research Institute (NERI) has developed the OML-Highway model and Ingenieurbüro Lohmeyer from Germany has developed SELMAGIS. The OML-Highway model is able to calculate air pollution concentr......This report describes the OML-Highway model and its integration into SELMAGIS. The National Environmental Research Institute (NERI) has developed the OML-Highway model and Ingenieurbüro Lohmeyer from Germany has developed SELMAGIS. The OML-Highway model is able to calculate air pollution...... concentration levels at receptor points along a highway road network, while SELMAGIS is a framework for calculating and representing air pollutant emissions and concentrations in a geographical information system (GIS)...

  10. Mathematical design of a highway exit curve

    Science.gov (United States)

    Pakdemirli, Mehmet

    2016-01-01

    A highway exit curve is designed under the assumption that the tangential and normal components of the acceleration of the vehicle remain constant throughout the path. Using fundamental principles of physics and calculus, the differential equation determining the curve function is derived. The equation and initial conditions are cast into a dimensionless form first for universality of the results. It is found that the curves are effected by only one dimensionless parameter which is the ratio of the tangential acceleration to the normal acceleration. For no tangential acceleration, the equation can be solved analytically yielding a circular arc solution as expected. For nonzero tangential acceleration, the function is complicated and no closed-form solutions exist for the differential equation. The equation is solved numerically for various acceleration ratios. Discussions for applications to highway exits are given.

  11. Accumulation of Pollutants in Highway Detention Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby

    This PhD study deals with issues related to water and pollutant transport from highway surfaces caused by rain. It is essential in the study to apply methods and models in which improvements in relation to removal of pollutants can be identified and to be able to predict the yearly discharges...... of heavy metals and polycyclic aromatic hydrocarbons from an arbitrary detention pond to the natural environment. The present thesis is a part of a co-operation between the Danish Road Directorate (Vejdirektoratet) and Aalborg University and is founded in the Danish construction act for new highways...... single rain event. From the hindcast results it is possible to calculate mean water and pollutant loads. This method is commonly used in urban drainage systems for capacity analysis or for prediction of CSO's. The challenge is to develop a simplified and still accurate description of flow and transport...

  12. Ecological stability of Tarim Desert Highway shelterbelt

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zhibin; XU Xinwen; LEI Jiaqiang; LI Shengyu

    2006-01-01

    The Tarim Desert Highway shelterbelt,located in hinterland of Taklimakan Desert, is irrigated by underground saline water, with three to thirty gram per litter mineral degrees. The sustainability and stability are affected by multifarious stress.The structural and functional characteristics of shelterbelt are studied to probe into correlation between environment and shelterbelt. On basis, decision analysis is applied to study ecological stability of the Tarim Desert Highway shelterbelt, to screen out limited factors, to establish general index system, and to evaluate the stability of the shelterbelt nowadays.Finally, the concept of ecological stability is utilized to manage the artificial ecosystem. The results show that the artificial ecosystem is relatively flimsy, whose stability can be increased by adjusting stand structure and improving the nutrient cycle.

  13. Alaska Highway bibliography, 3rd edition

    DEFF Research Database (Denmark)

    Prange, Laurie

    Since the early 20th century various schemes were considered for the construction of roads, trails or railways 71 to link the Yukon, northern British Columbia and Alaska to the “outside.” These schemes were motivated by economic interests, including mining, lumber and tourism concerns. During the....... The impacts included an increased awareness of the world outside of the Yukon, imported ideas and technology, improved health care, highway transportation, telecommunications, and the development of more mining and tourist-related industries....... land route to Alaska for defence purposes. The military was not interested in developing or planning a highway for the civilian needs of the future. The chosen route ran from Edmonton to Whitehorse, then on to Fairbanks. The U.S. Army and U.S. Public Roads Administration (PRA) roughed out a “pioneer...

  14. The influence of tollbooths on highway traffic

    Science.gov (United States)

    Huang, Ding-wei; Huang, Wei-neng

    2002-09-01

    We study the effects of tollbooths on the traffic flow. The highway traffic is simulated by the Nagel-Schreckenberg model. Various types of toll collection are examined, which can be characterized either by a waiting time or a reduced speed. A first-order phase transition is observed. The phase separation results a saturated flow, which is observed as a plateau region in the fundamental diagram. The effects of lane expansion near the tollbooth are examined. The full capacity of a highway can be restored. The emergence of vehicle queuing is studied. Besides the numerical results, we also obtain analytical expressions for various quantities. The numerical simulations can be well described by the analytical formulas. We also discuss the influence on the travel time and its variance. The tollbooth increases the travel time but decreases its variance. The differences between long- and short-distance travelers are also discussed.

  15. Approximating Mexican highways with slime mould

    CERN Document Server

    Adamatzky, Andrew; Chapa-Vergara, Sergio V; Asomoza-Palacio, Rene; Stephens, Christopher R

    2010-01-01

    Plasmodium of Physarum polycephalum is a single cell visible by unaided eye. During its foraging behavior the cell spans spatially distributed sources of nutrients with a protoplasmic network. Geometrical structure of the protoplasmic networks allows the plasmodium to optimize transport of nutrients between remote parts of its body. Assuming major Mexican cities are sources of nutrients how much structure of Physarum protoplasmic network correspond to structure of Mexican Federal highway network? To find an answer undertook a series of laboratory experiments with living Physarum polycephalum. We represent geographical locations of major cities by oat flakes, place a piece of plasmodium in Mexico city area, record the plasmodium's foraging behavior and extract topology of nutrient transport networks. Results of our experiments show that the protoplasmic network formed by Physarum is isomorphic, subject to limitations imposed, to a network of principle highways. Ideas and results of the paper may contribute tow...

  16. The Full Cost of Intercity Highway Transportation

    OpenAIRE

    David Levinson; David Gillen

    1997-01-01

    In this paper we review the theoretical and empirical literature on the cost structure of the provision of intercity highway transportation and specify and estimate our own cost functions . We develop a full cost model which identifies the key cost components and then estimate costs component by component: user costs, infrastructure costs, time and congestion costs, noise costs, accident costs, and pollution costs. The total long run average cost is $0.34 per vehicle kilometer traveled. The s...

  17. Sound absorption mapping of highway noise barrier

    OpenAIRE

    Grosso, Andrea

    2012-01-01

    International audience; Sound propagation from highway to the urban areas can be reduced using noise barriers. The general computational modeling takes typically into account sound ray lines, reflection and diffraction, although the absorption distribution over the surface in not considered. The sound absorption coefficient can be calculated using a PU probe, by the impedance measured “in situ” close by the surface. Well known methods are available on the market for estimating the sound absor...

  18. Biological evaluation of Trans-African highways

    Science.gov (United States)

    Adamatzky, Andrew; Kayem, Anne V. D. M.

    2013-01-01

    The Trans-African highway network is a unique concept of integrated development of transport corridors spanning all African countries and providing landlocked countries access to seaports. The planned road system is still maturing and just partially complete, thus giving us a chance to play with different scenarios of its growth and to consider potential alternative transport networks. We study the evolving transport network in the African continent with a groundbreaking technique of imitating growing transport networks with slime mould Physarum polycephalum. We represent the major urban areas of Africa with a source of nutrients, inoculate a piece of the slime mould in Cairo and allow the mould to span all urban areas with its network of protoplasmic tubes. We then compare the slime mould networks with existing and planned highway corridors. We found that slime mould provides a good approximation of the Trans-African highway network, with some roads of Eastern Africa delineated by P. polycephalum in a larger number of laboratory experiments. We demonstrate direct matches between protoplasmic tubes and Trans-Sahelian as well as Lagos-Mombasa corridors. Finally we analyse the bio-logic of transport network development in families of generalised Physarum graphs.

  19. Effective flow resistivity of highway pavements.

    Science.gov (United States)

    Rochat, Judith L; Read, David R

    2013-12-01

    In the case of highway traffic noise, propagating sound is influenced by the ground over which it travels, whether it is the pavement itself or the ground between the highway and nearby communities. Properly accounting for ground type in modeling can increase accuracy in noise impact determinations and noise abatement design. Pavement-specific effective flow resistivity values are being investigated for inclusion in the Federal Highway Administration Traffic Noise Model, which uses these values in the sound propagation algorithms and currently applies a single effective flow resistivity value to all pavement. Pavement-specific effective flow resistivity values were obtained by applying a modified version of the American National Standards Institute S1.18 standard. The data analysis process was tailored to allow for increased sensitivity and extraction of effective flow resistivity values for a broad range of pavements (sound absorptive to reflective). For porous pavements (sound absorptive), it was determined that examination of the measured data can reveal influence from an underlying structure. Use of such techniques can aid in the design of quieter pavements.

  20. Contributions of vital rates to growth of a protected population of American black bears

    Science.gov (United States)

    Mitchell, M.S.; Pacifici, L.B.; Grand, J.B.; Powell, R.A.

    2009-01-01

    Analyses of large, long-lived animals suggest that adult survival generally has the potential to contribute more than reproduction to population growth rate (??), but because survival varies little, high variability in reproduction can have a greater influence. This pattern has been documented for several species of large mammals, but few studies have evaluated such contributions of vital rates to ?? for American black bears (Ursus americanus). We used variance-based perturbation analyses (life table response experiments, LTRE) and analytical sensitivity and elasticity analyses to examine the actual and potential contributions of variation of vital rates to variation in growth rate (??) of a population of black bears inhabiting the Pisgah Bear Sanctuary in the southern Appalachian Mountains of North Carolina, using a 22-year dataset. We found that recruitment varied more than other vital rates; LTRE analyses conducted over several time intervals thus indicated that recruitment generally contributed at least as much as juvenile and adult survival to observed variation in ??, even though the latter 2 vital rates had the greater potential to affect ??. Our findings are consistent with predictions from studies on polar bears (U. maritimus) and grizzly bears (U. arctos), but contrast with the few existing studies on black bears in ways that suggest levels of protection from human-caused mortality might explain whether adult survival or recruitment contribute most to variation in ?? for this species. We hypothesize that ?? is most strongly influenced by recruitment in protected populations where adult survival is relatively high and constant, whereas adult survival will most influence ?? for unprotected populations. ?? 2009 International Association for Bear Research and Management.

  1. Optimum Design of Highway Excavation Slope Angle: Evidence from Dawu Section of Jingzhu Highway

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The optimum design of the highway excavation slope angle is one of the most important problems to the highway construction and to the slope improvement. The Dawu Section of Jingzhu (Beijing-Zhuhai) Highway is taken as an example to illustrate the study method for excavation slope angle design.The analysis of the engineering condition from different angles with different factors shows that the stability of the slope is calculated by using residual pushing force and the Sarma method. Then the sensitive analysis of the slope stability is conducted by using residual pushing force method. Finally, the optimum angle of design is presented on the precondition of ensuring the whole stability of slope and the economic reasonability. The study results show that the most sensitive factors are the shear strength parameter and t he seismic force, and that the optimum excavation slope angle is 60°.``

  2. Axial Halbach Magnetic Bearings

    Science.gov (United States)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2008-01-01

    Axial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control.

  3. 26 CFR 41.4482(a)-1 - Definition of highway motor vehicle.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Definition of highway motor vehicle. 41.4482(a... (CONTINUED) MISCELLANEOUS EXCISE TAXES EXCISE TAX ON USE OF CERTAIN HIGHWAY MOTOR VEHICLES Tax on Use of Certain Highway Motor Vehicles § 41.4482(a)-1 Definition of highway motor vehicle. (a) Highway...

  4. 78 FR 26847 - Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses

    Science.gov (United States)

    2013-05-08

    ... Federal Highway Administration Including Specific Pavement Types in Federal-aid Highway Traffic Noise... types used in Federal-aid highway traffic noise analyses. Current highway traffic noise analyses rely on... suggestions on whether and how to include additional pavement types in Federal-aid highway traffic...

  5. Cryogenic Hybrid Magnetic Bearing

    Science.gov (United States)

    Meeks, Crawford R.; Dirusso, Eliseo; Brown, Gerald V.

    1994-01-01

    Cryogenic hybrid magnetic bearing is example of class of magnetic bearings in which permanent magnets and electromagnets used to suspend shafts. Electromagnets provide active control of position of shaft. Bearing operates at temperatures from -320 degrees F (-196 degrees C) to 650 degrees F (343 degrees C); designed for possible use in rocket-engine turbopumps, where effects of cryogenic environment and fluid severely limit lubrication of conventional ball bearings. This and similar bearings also suitable for terrestrial rotating machinery; for example, gas-turbine engines, high-vacuum pumps, canned pumps, precise gimbals that suspend sensors, and pumps that handle corrosive or gritty fluids.

  6. TOPICAL REVIEW: Superconducting bearings

    Science.gov (United States)

    Hull, John R.

    2000-02-01

    The physics and technology of superconducting bearings is reviewed. Particular attention is given to the use of high-temperature superconductors (HTSs) in rotating bearings. The basic phenomenology of levitational forces is presented, followed by a brief discussion of the theoretical models that can be used for conceptual understanding and calculations. The merits of various HTS bearing designs are presented, and the behaviour of HTS bearings in typical situations is discussed. The article concludes with a brief survey of various proposed applications for HTS bearings.

  7. Good neighbours: even bears kept happy by the new approach to wilderness project

    Energy Technology Data Exchange (ETDEWEB)

    Stonehouse, D.

    2000-04-01

    Experiences gained by Husky Oil and Rigel Energy drilling a successful exploratory well in Kananaskis country, Calgary's wilderness playground, are described. 'Fitting in' with the character of 'K-country' entailed developing a plan acceptable to recreational users, aboriginal groups, government agencies, and environmentalists. The result was a landmark effort in industrial adaptation to nature: the Eastern Slope Grizzly Bear Project, a major cumulative effects assessment, which is now gaining acceptance as an industry model. The assessment involved surveying the distribution of deer, elk, moose, sheep, rare plants, breeding birds and fish species and the tracking and mapping of the movements of bears, to get a complete picture of the health of the eastern slope habitat, and to provide the foundation for assessing development and land use. The study showed Husky Oil how to proceed without doing environmental damage. It influenced the manner in which the field was delineated, it altered production tests, it forced reinjection of fluids and gas during well testing rather than hauling it away in trucks, it determined the type and route for the access road and later the location of the pipeline, all in an effort to stay clear of high quality ungulate and bear habitat. It was time consuming and expensive, but according to company officials, well worth it. Development was also influenced by traditional land use and preservation of native cultural resources; for example, the pipeline was rerouted to avoid archaeological sites.

  8. Teddy Bear Stories

    DEFF Research Database (Denmark)

    van Leeuwen, Theo; Caldas-Coulthardt, Carmen

    2014-01-01

    This paper presents a semiotic analysis of a key cultural artefact, the teddy bear. After introducing the iconography of the teddy bear, it analyses different kinds of stories to show how teddy bears are endowed with meaning in everyday life: stories from children's books, reminiscenses by adults...... about their childhood teddy bears, and children's accounts of what they do with teddy bears, both written for school and told 'out of school', The chapter sees teddy bears as artefacts that provide a cultural channeling for the child's need of a transitional object and argues that the meanings of teddy...... bears have traditionally centred on interpersonal relations within the nuclear family, but have recently been institutionalized and commercialized....

  9. OPTIMIZING HIGHWAY PROFILES FOR INDIVIDUAL COST ITEMS

    Directory of Open Access Journals (Sweden)

    Essam Dabbour

    2013-12-01

    Full Text Available According to the current practice, vertical alignment of a highway segment is usually selected by creating a profile showing the actual ground surface and selecting initial and final grades to minimize the overall cut and fill quantities. Those grades are connected together with a parabolic curve. However, in many highway construction or rehabilitation projects, the cost of cut may be substantially different from that of fill (e.g. in extremely hard soils where blasting is needed to cut the soil. In that case, an optimization process will be needed to minimize the overall cost of cut and fill rather than to minimize their quantities. This paper proposes a nonlinear optimization model to select optimum vertical curve parameters based on individual cost items of cut and fill. The parameters selected by the optimization model include the initial grade, the final grade, the station and elevation of the point of vertical curvature (PVC, and the station and elevation of the point of vertical tangency (PVT. The model is flexible to include any design constraints for particular design problems. Different application examples are provided using the Evolutionary Algorithm in Microsoft Excel’s Solver add-in. The application examples validated the model and demonstrated its advantage of minimizing the overall cost rather than minimizing the overall volume of cut and fill quantities.

  10. CAUSES OF HIGHWAY FAILURES IN NIGERIA.

    Directory of Open Access Journals (Sweden)

    DR. NDEFO OKIGBO

    2012-11-01

    Full Text Available Most of the road networks in the developing countries of Africa are in deplorable conditions. Nigeria being one of these countries is not an exception. The conditions of the roads in Nigeria were examined. The causes of these conditions of the roads in Nigeria were articulated and their effects to the citizen, government and theeconomy of the country were highlighted and solutions to these problems given in the form of recommendations that will remedy the situation. Some of the identified causes were; poor design and construction, poor maintenance of already built highways, use of low quality materials in construction, poor workmanship and poorsupervision of construction work and the plying of heavy traffic that were not meant for the road on the road. Some of the recommendations to remedy the situation are; Use of the appropriate design of the roads, avoiding unnecessary congestion of the roads with traffic especially heavy traffics that were not meant for the roads inthe first place, prompt maintenance of the roads, application of suitable construction material in the construction of the roads, applying appropriate tests to the soil in road construction, use of qualified engineering personnel in road construction and the application of sanctions for highway failures.

  11. Fracture of highway and airport pavements

    Science.gov (United States)

    Ramsamooj, D. V.

    1993-03-01

    Existing solutions for the stresses in a cracked slab containing a crack and supported by an elastic foundation are extended to obtain the stress intensity factor (SIF) for a crack in a pavement subjected to moving vehicular loads. In the existing solutions the stresses can be obtained only for a uniform bending stress (before the crack occurs) along the crack surface. For pavements subjected to moving vehicular loads, the stress distribution along the crack surface is not uniform and the approximation of a uniform stress is often unsatisfactory. The present work extends the above solutions to cover more realistic loading of highway and airport pavements. This facilitates the application of the principles of fracture mechanics to the fatigue crack propagation and fracture of pavements. Beginning with a part-through semi-elliptical starter crack, the crack is assumed to grow under load and the SIF is presented at various stages of crack growth, from the starter crack into a short through-crack that eventually becomes a very long through-crack. Some examples of the fracture of typical rigid and flexible highway and airport pavements are presented to show the need to consider fracture in the design of pavements.

  12. Off-Highway Transportation-Related Fuel Use

    Energy Technology Data Exchange (ETDEWEB)

    Davis, S.C.

    2004-05-08

    The transportation sector includes many subcategories--for example, on-highway, off-highway, and non-highway. Use of fuel for off-highway purposes is not well documented, nor is the number of off-highway vehicles. The number of and fuel usage for on-highway and aviation, marine, and rail categories are much better documented than for off-highway land-based use. Several sources document off-highway fuel use under specific conditions--such as use by application (e.g., recreation) or by fuel type (e.g., gasoline). There is, however, no single source that documents the total fuel used off-highway and the number of vehicles that use the fuel. This report estimates the fuel usage and number of vehicles/equipment for the off-highway category. No new data have been collected nor new models developed to estimate the off-highway data--this study is limited in scope to using data that already exist. In this report, unless they are being quoted from a source that uses different terminology, the terms are used as listed below. (1) ''On-highway/on-road'' includes land-based transport used on the highway system or other paved roadways. (2) ''Off-highway/off-road'' includes land-based transport not using the highway system or other paved roadways. (3) ''Non-highway/non-road'' includes other modes not traveling on highways such as aviation, marine, and rail. It should be noted that the term ''transportation'' as used in this study is not typical. Generally, ''transportation'' is understood to mean the movement of people or goods from one point to another. Some of the off-highway equipment included in this study doesn't transport either people or goods, but it has utility in movement (e.g., a forklift or a lawn mower). Along these lines, a chain saw also has utility in movement, but it cannot transport itself (i.e., it must be carried) because it does not have wheels. Therefore

  13. 75 FR 17829 - Motorcyclist Advisory Council to the Federal Highway Administration

    Science.gov (United States)

    2010-04-07

    ... Federal Highway Administration Motorcyclist Advisory Council to the Federal Highway Administration AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of meeting of advisory committee. SUMMARY: This document announces the eighth meeting of the Motorcyclist Advisory Council to the Federal...

  14. 77 FR 24560 - National Highway Traffic Safety Administration Electric Vehicle Safety Technical Symposium

    Science.gov (United States)

    2012-04-24

    ... National Highway Traffic Safety Administration Electric Vehicle Safety Technical Symposium AGENCY: National Highway Traffic Safety Administration (NHTSA), Department of Transportation (DOT). ACTION: Announcement of public symposium. SUMMARY: The National Highway Traffic Safety Administration (NHTSA) is announcing...

  15. 75 FR 55628 - National Highway Traffic Safety Administration Reports, Forms and Record Keeping Requirements...

    Science.gov (United States)

    2010-09-13

    ... National Highway Traffic Safety Administration Reports, Forms and Record Keeping Requirements: Agency Information Collection Activity Under OMB Review AGENCY: National Highway Traffic Safety Administration (NHTSA... National Highway Traffic Safety Administration (NHTSA), Office of Crash Avoidance Standards...

  16. 76 FR 17615 - Highway-Rail Grade Crossing; Safe Clearance

    Science.gov (United States)

    2011-03-30

    ... Parts 177 and 392 RIN 2137-AE69 & 2126-AB04 Highway-Rail Grade Crossing; Safe Clearance AGENCY: Pipeline... that PHMSA and FMCSA extend the comment period for the Highway-Rail Grade Crossing; Safe Clearance... Crossing; Safe Clearance Notice of Proposed Rulemaking, which was published on January 28, 2011 (76 FR...

  17. 49 CFR 325.35 - Ambient conditions; highway operations.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Ambient conditions; highway operations. 325.35... Ambient conditions; highway operations. (a)(1) Sound. The ambient A-weighted sound level at the microphone... § 325.23. (2) The measured ambient level must be 10 dB(A) or more below that level specified in §...

  18. 14 CFR 93.68 - General rules: Seward Highway segment.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false General rules: Seward Highway segment. 93.68 Section 93.68 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Area § 93.68 General rules: Seward Highway segment. (a) Each person operating an airplane in the...

  19. 23 CFR 200.9 - State highway agency responsibilities.

    Science.gov (United States)

    2010-04-01

    ... Administration. (2) Section 162a of the Federal-Aid Highway Act of 1973 (section 324, title 23 U.S.C.) requires... requirements of section 162a of the Federal-Aid Highway Act of 1973 have been added to its assurances. (3)...

  20. Mathematical model of transportation flow dynamics on a multilane highway

    NARCIS (Netherlands)

    Mazurin, D. S.

    2013-01-01

    We present a microscopic model for the dynamics of a transportation flow based on cellular automata with improved lane changing rules. With this model, we study the influence of crossing transportation flows on the throughput of a multilane highway. For a two-lane highway with an exit, we obtain spa

  1. Highway Safety Program Manual: Volume 7: Traffic Courts.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    Volume 7 of the 19-volume Highway Safety Program Manual (which provides guidance to State and local governments on preferred highway safety practices) focuses on traffic courts, their purpose and objectives. Federal authority in the area of traffic courts are described. Program development and operations (a study of courts trying traffic cases, a…

  2. New highway development in the Netherlands: a residents' perspective

    NARCIS (Netherlands)

    Hamersma, Marije

    2017-01-01

    This study investigates the impacts of new highway development from a residents’ perspective. Data were collected by questionnaire in two residential areas, Son and Uden, both situated along the new A50 highway in the Netherlands. The objectives of this study are: 1) to analyse the extent to which h

  3. EcoBears

    DEFF Research Database (Denmark)

    Nielsen, Nick; Pedersen, Sandra Bleuenn; Sørensen, Jens Ager

    2015-01-01

    In this paper, we introduce the EcoBears concept that aims to augment household appliances with functional and aesthetic features to promote their "use'' and "longevity of use'' to prevent their disposal. The EcoBears also aim to support the communication of environmental issues in the home setting....... We present our initial design and implementation of the EcoBears that consist of two bear modules (a mother and her cub). We also present our preliminary concept validations and lessons learned to be considered for future directions....

  4. Interaction study of permafrost and highway along Qinghai-Xizang Highway

    Institute of Scientific and Technical Information of China (English)

    WU; Qingbai; (吴青柏); SHI; Bin; (施; 斌); LIU; Yongzhi; (刘永智)

    2003-01-01

    Eight monitoring sites are set along the Qinghai-Xizang Highway (QXH) to investigate the characteristics and process of interaction between permafrost and highway, including the upper and down boundaries of active layer under natural surface, seasonally freezing-thawing depth under asphalt pavement, permafrost table temperature and roadbed stability. The investigation results show that the changes of active layer thickness and permafrost table temperature under asphalt pavement are greater than these under natural surface due to the absorbing heat action and less evaporation of asphalt pavement, as a result, the engineering geological problems such as thaw settlement and frost heave present frequently along QXH line and produce the adverse impact on roadbed stability.

  5. Highway bridge seismic design: summary of FHWA/MCEER project on seismic vulnerability of new highway construction

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Federal Highway Administration (FHWA) sponsored a large, multi-year project conducted by theMultidisciplinary Center for Earthquake Engineering Research (MCEER) titled "Seismic Vulnerability of New HighwayConstruction" (MCEER Project 112), which was completed in 1998. MCEER coordinated the work of many researchers, whoperformed studies on the seismic design and vulnerability analysis of highway bridges, tunnels, and retaining structures.Extensive research was conducted to provide revisions and improvements to current design and detailing approaches andnational design specifications for highway bridges. The program included both analytical and experimental studies, andaddressed seismic hazard exposure and ground motion input for the U.S. highway system; foundation design and soil behavior;structural importance, analysis, and response; structural design issues and details; and structural design criteria.

  6. Evaluation of the New Jersey Digital Highway

    Directory of Open Access Journals (Sweden)

    Judy Jeng

    2008-12-01

    Full Text Available The aim of this research is to study the usefulness of the New Jersey Digital Highway (NJDH, www.njdigitalhighway.org and its portal structure. The NJDH intends to provide an immersive and user-centered portal for New Jersey history and culture. The research recruited 145 participants and used a Web-based questionnaire that contained three sections: for everyone, for educators, and for curators. The feedback on the usefulness of the NJDH was positive and the portal structure was favorable. The research uncovered several reasons why some collections did not want to or could not participate. The findings also suggested priorities for further development. This study is one of the few on the evaluation of cultural heritage digital library.

  7. Optimum Maintenance Strategies for Highway Bridges

    DEFF Research Database (Denmark)

    Frangopol, Dan M.; Thoft-Christensen, Palle; Das, Parag C.;

    As bridges become older and maintenance costs become higher, transportation agencies are facing challenges related to implementation of optimal bridge management programs based on life cycle cost considerations. A reliability-based approach is necessary to find optimal solutions based on minimum...... expected life-cycle costs or maximum life-cycle benefits. This is because many maintenance activities can be associated with significant costs, but their effects on bridge safety can be minor. In this paper, the program of an investigation on optimum maintenance strategies for different bridge types...... is described. The end result of this investigation will be a general reliability-based framework to be used by the UK Highways Agency in order to plan optimal strategies for the maintenance of its bridge network so as to optimize whole-life costs....

  8. Autoimmunity and the highway to diabetes.

    Science.gov (United States)

    Price, P

    1997-02-01

    Insulin-dependent diabetes mellitus (IDDM) is an immunopathological condition involving loss of beta cell function, but views of how this arises are confusing and contradictory. For example, studies with non-obese diabetic mice implicate abnormal cytokine production in disease pathogenesis, but give little insight into how this arises. Many genetic and environmental risk factors have been described, but no single factor predicts the development of disease. Moreover, the prevalence of auto-antibodies suggests an autoimmune aetiology, but no antigen is recognized by all individuals. As an aid to understanding how IDDM develops, this review considers the risk factors as distinct starting points on a journey, and reviews current literature in search of the point where the roads from each origin merge into a highway to diabetes.

  9. Forensic aspects of the highway crash.

    Science.gov (United States)

    Gikas, P W

    1983-01-01

    It can be stated that patterns of injury in highway crashes can often be related to specific design and damage features of the vehicle. The restraint systems designed to attenuate injury may also, under severe crash circumstances, produce trauma. Problems may arise as to identification of vehicular drivers. It behooves the pathologist concerned with the necropsy of crash victims and the physician responsible for treating crash victims to become familiar with the pathogenesis of injuries. Such knowledge can be utilized in the recommendation for improvement of vehicles to render them more crashworthy. Awareness of the various mechanisms of injury in vehicle crashes also enhances the diagnostic skill of the initial treating physician when he or she is confronted with a crash victim in the emergency department. Ideally, when the victim arrives at the hospital, the emergency room physician should be supplied with the details of the crash including the type of vehicle, position within the vehicle, use or nonuse of restraint systems, and the direction of the impact. When a fatality results from a car crash, ideally the autopsy pathologist should inspect the vehicle or at least view pictures of the exterior and interior of the vehicle to help establish the pathogenesis of injury in a specific collision. Unfortunately, because of time constraints, this ideal is not always achieved. Because of the considerable volume of civil and criminal litigation resulting from highway crashes, there is a need for competent medical expertise to help both the plaintiff and the defendent. The pathologist involved in forensic work and the treating physician play a particularly important role in the judicial arena.

  10. 23 CFR Appendix D to Subpart A of... - Guidance Criteria for Evaluating Requests for Modifications to the National Highway System

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Guidance Criteria for Evaluating Requests for Modifications to the National Highway System D Appendix D to Subpart A of Part 470 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PLANNING AND RESEARCH HIGHWAY SYSTEMS Federal-aid Highway Systems...

  11. Damper bearing rotordynamics

    Science.gov (United States)

    Elrod, David A.

    1990-01-01

    High side loads reduce the life of the Space Shuttle Main Engine (SSME) High Pressure Oxygen Turbopump (HPOTP) bearings. High stiffness damper seals were recommended to reduce the loads on the pump and turbine end bearings in the HPOTP. The seals designed for use on the pump end are expected to adequately reduce the bearing loads; the predicted performance of the planned turbine end seal is marginal. An alternative to the suggested turbine end seal design is a damper bearing with radial holes from the pressurized center of the turbopump rotor, feeding a smooth land region between two rough-stator/smooth-rotor annular seals. An analysis was prepared to predict the leakage and rotor dynamic coefficients (stiffness, damping, and added mass) of the damper bearing. Governing equations of the seal analysis modified to model the damper bearing; differences between the upstream conditions of the damper bearing and a typical annular seal; prediction of the damper bearing analysis; and assumptions of the analysis which require further investigation are described.

  12. The Grizzly Lake complex (Yellowstone Volcano, USA): Mixing between basalt and rhyolite unraveled by microanalysis and X-ray microtomography

    Science.gov (United States)

    Morgavi, Daniele; Arzilli, Fabio; Pritchard, Chad; Perugini, Diego; Mancini, Lucia; Larson, Peter; Dingwell, Donald B.

    2016-09-01

    Magma mixing is a widespread petrogenetic process. It has long been suspected to operate in concert with fractional crystallization and assimilation to produce chemical and temperature gradients in magmas. In particular, the injection of mafic magmas into felsic magma chambers is widely regarded as a key driver in the sudden triggering of what often become highly explosive volcanic eruptions. Understanding the mechanistic event chain leading to such hazardous events is a scientific goal of high priority. Here we investigate a mingling event via the evidence preserved in mingled lavas using a combination of X-ray computed microtomographic and electron microprobe analyses, to unravel the complex textures and attendant chemical heterogeneities of the mixed basaltic and rhyolitic eruption of Grizzly Lake in the Norris-Mammoth corridor of the Yellowstone Plateau volcanic field (YVF). We observe evidence that both magmatic viscous inter-fingering of magmas and disequilibrium crystallization/dissolution processes occur. Furthermore, these processes constrain the timescale of interaction between the two magmatic components prior to their eruption. X-ray microtomography images show variegated textural features, involving vesicle and crystal distributions, filament morphology, the distribution of enclaves, and further textural features otherwise obscured in conventional 2D observations and analyses. Although our central effort was applied to the determination of mixing end members, analysis of the hybrid portion has led to the discovery that mixing in the Grizzly Lake system was also characterized by the disintegration and dissolution of mafic crystals in the rhyolitic magma. The presence of mineral phases in both end member, for example, forsteritic olivine, sanidine, and quartz and their transport throughout the magmatic mass, by a combination of both mixing dynamics and flow imposed by ascent of the magmatic mass and its eruption, might have acted as a "geometric

  13. High Black Carbon (BC) Concentrations along Indian National Highways

    Science.gov (United States)

    Kumar, S.; Singh, A. K.; Singh, R. P.

    2015-12-01

    Abstract:Black carbon (BC), the optically absorbing component of carbonaceous aerosol, has direct influence on radiation budget and global warming. Vehicular pollution is one of the main sources for poor air quality and also atmospheric pollution. The number of diesel vehicles has increased on the Indian National Highways during day and night; these vehicles are used for the transport of goods from one city to another city and also used for public transport. A smoke plume from the vehicles is a common feature on the highways. We have made measurements of BC mass concentrations along the Indian National Highways using a potable Aethalometer installed in a moving car. We have carried out measurements along Varanasi to Kanpur (NH-2), Varanasi to Durgapur (NH-2), Varanasi to Singrauli (SH-5A) and Varanasi to Ghazipur (NH-29). We have found high concentration of BC along highways, the average BC mass concentrations vary in the range 20 - 40 µg/m3 and found high BC mass concentrations up to 600 μg/m3. Along the highways high BC concentrations were characteristics of the presence of industrial area, power plants, brick kilns and slow or standing vehicles. The effect of increasing BC concentrations along the National Highways and its impact on the vegetation and human health will be presented. Key Words: Black Carbon; Aethalometer; mass concentration; Indian National Highways.

  14. An Innovative Strategy for Maintenance of Highway Pavement

    Directory of Open Access Journals (Sweden)

    Sandeep Choudhary, Dr. P. K. Agarwal

    2013-05-01

    Full Text Available Highway pavement are deteriorating fast due to lack of timely maintenance, leading to higher vehicle operating costs, increasing number of accidents etc. Thus, timely maintenance of the highway pavement is essential. Because, once pavements start to deteriorate; they deteriorate rapidly beyond the point where maintenance is effective. Thus, there is an urgent need to develop a strategy for maintenance of pavement in a huge highway network. In this study, an innovative strategy for maintenance of highway pavement is proposed. A two stage maintenance strategy is proposed. In stage I, it is proposed to determine priority of highway sections. In Stage II, priority of various maintenance activities to be carried out on various sections will be determined. Maintenance priority of the pavement is based on importance of the road sections, present road conditions, and future road conditions. The methodology proposed in this study is illustrated with the help of example of some hypothetical highway network consisting of 4 sections. Analysis results indicated that the proposed strategy is considered to be more rational, innovative & logical. Some strategies for maintenance of urban roads are also presented in this study. Therefore, it is expected that this study will be useful for maintenance of huge highway network in India and thus will be useful for preserving huge asset of pavement infrastructure.

  15. Geotechnical assessment of road failure and slope monitoring along Nsukka-Adoru-Idah highway, Southeastern Nigeria.

    Science.gov (United States)

    Maduka, Raphael Iweanya; Igwe, Ogbonnaya; Ayogu, Nnadozie Onyekachi; Ayogu, Chinero Nneka; Nwachukwu, Martin

    2017-01-01

    The quality of highway pavement is greatly influenced by the subgrade materials, the general geology of the area, and the materials used for construction. Investigation into the 75-km Nsukka-Adoru-Idah highway revealed that the pavement was underlain by three lithological units-Imo, Nsukka, and Ajali formations. The geotechnical evaluation carried out in the study includes the particle size distribution, Atterberg limit, specific gravity, compaction tests, and California bearing ratio (CBR). The base course has clay/silt (7-14%), fine sand (1-4%), medium sand (6-13%), and coarse sand (65-86%), while the subgrade presented clay/silt (74-82%), fine sand (6-9%), medium sand (10-17%), and coarse sand (1-3%). The average specific gravity results for the studied base course and subgrades are 2.58 and 2.52. Liquid limit (LL) result ranges from 27 to 60%, while plastic limit (PL) ranges between 17 and 24%, and plasticity index (PI) ranges from 5 to 39%. The maximum dry density (MDD) result ranges from 1.70 to 2.10 mg/m(3), while the optimum moisture content (OMC) for the samples ranges between 14.1 and 18.0%. The CBR result for soaked and unsoaked samples ranges from 37 to 74 and 48 to 83%, respectively. The low unsoaked CBR ( 30% and PI > 12%) failed the stipulated Nigerian standard, signifying the need for stabilization. A geotechnical model of a highway road cut generated a factor of safety of 1.45, indicating possibility of slope failure.

  16. Effects of Bamboo Leaf Ash on Lime Stabilized Lateritic Soil for Highway Construction

    Directory of Open Access Journals (Sweden)

    S.S. Babajide

    2011-04-01

    Full Text Available This research determined the effects of bamboo leaf ash on lime stabilized lateritic soil for highway construction. It was necessary to utilize the properties of waste materials such as bamboo leaf in order to determine its usefulness as a possible complement stabilizer for lime and hence reduce highway construction cost. The three samples A, B and C used in this study were collected from different locations in Ile-Ife, Nigeria. Preliminary tests such as the natural moisture content, specific gravity, grain size analysis and Atterberg’s limits were performed on them at their natural states and when stabilized with optimum percentages of lime. Engineering tests such as compaction, California Bearing Ratio (CBR and undrained traixial were also performed on them at their natural states, when stabilized with the optimum lime percentages and when Bamboo Leaf Ash (BLA was introduced at 2, 4 and 6% to the samples. The results of the strength tests showed that BLA improved the strengths of all the lime stabilized samples. The unsoaked CBR values increased from 4-11, 2-10 and 2-11%, respectively in lime stabilized samples A, B and C with the addition of BLA. The shear strengths also increased substantially, from 42.16 to 398.96 kN/m2, 42.96 to 146.84 kN/m2 and 197.48 to 365.90 kN/m2, respectively with the addition of BLA to the lime stabilized samples. It was therefore concluded that BLA will further increase the strength of lime stabilized lateritic soil for highway construction since it was found as an effective complement for lime in soil stabilization.

  17. Touchdown Ball-Bearing System for Magnetic Bearings

    Science.gov (United States)

    Kingsbury, Edward P.; Price, Robert; Gelotte, Erik; Singer, Herbert B.

    2003-01-01

    The torque-limited touchdown bearing system (TLTBS) is a backup mechanical-bearing system for a high-speed rotary machine in which the rotor shaft is supported by magnetic bearings in steady-state normal operation. The TLTBS provides ball-bearing support to augment or supplant the magnetic bearings during startup, shutdown, or failure of the magnetic bearings. The TLTBS also provides support in the presence of conditions (in particular, rotational acceleration) that make it difficult or impossible to control the magnetic bearings or in which the magnetic bearings are not strong enough (e.g., when the side load against the rotor exceeds the available lateral magnetic force).

  18. Characteristics of Bamboo Leaf Ash Stabilization on Lateritic Soil in Highway Construction

    Directory of Open Access Journals (Sweden)

    Akinwole A. Adetuberu

    2010-08-01

    Full Text Available This research was carried out to study the characteristics of bamboo leaf ash stabilization on lateritic soil in highway construction. Preliminary tests were performed on three samples, A, B, and C foridentification and classification purposes followed by the consistency limit tests. Geotechnical property tests (compaction, California bearing ratio (CBR, and triaxial were also performed on the samples, both at the stabilized and unstabilized states by adding 2, 4, 6, 8 and 10% bamboo leaf ash (BLA by weight of sample tothe soils. The results showed that the addition of BLA improved the strengths of the samples. Optimum moisture contents reduced to 20.20, 19.60 and 9.32% at 8, 4 and 6% BLA additions in samples A, B and Crespectively while MDD increased to 1400, 1676 and 1941 kg/m3 respectively at 8, 2 and 4% BLA additions in samples A, B, and C. The unsoaked CBR values of samples A and B increased from 5.44 to 38.21% and from 11.42 to 34.99% respectively. The shear strengths of samples A and B also increased from 181.31 to 199.00 kN/m2 and from 144.81 to 155.90 kN/m2 respectively. It was therefore concluded that bamboo leaf ash has a good potential for stabilizing lateritic soils in highway construction.

  19. Ultra-precision bearings

    CERN Document Server

    Wardle, F

    2015-01-01

    Ultra-precision bearings can achieve extreme accuracy of rotation, making them ideal for use in numerous applications across a variety of fields, including hard disk drives, roundness measuring machines and optical scanners. Ultraprecision Bearings provides a detailed review of the different types of bearing and their properties, as well as an analysis of the factors that influence motion error, stiffness and damping. Following an introduction to basic principles of motion error, each chapter of the book is then devoted to the basic principles and properties of a specific type of bearin

  20. Electronic Highway or Weaving Loom? Thinking about Conferencing Technologies for Learning.

    Science.gov (United States)

    Burge, Elizabeth J.

    Information highways are high speed data networks used to transport information and link people together. As more limitations of and problems with the information highway ("potholes") become apparent, the highway metaphor may have to be revisited, and the information highway must be examined with a critical eye. Distance educators…

  1. 23 CFR 500.204 - TMS components for highway traffic data.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false TMS components for highway traffic data. 500.204 Section... for highway traffic data. (a) General. Each State's TMS, including those using alternative procedures... highway traffic data shall include the testing of equipment used in the collection of the data....

  2. Highway Construction Management%公路施工管理

    Institute of Scientific and Technical Information of China (English)

    张华

    2015-01-01

    In the highway construction, the construction process should be scientific, reasonable management, and in the latter do a good job in the maintenance work, to ensure the quality of the highway. Based on this, this paper analyzes the highway construction management, in order to promote the sustainable development of highway engineering in China.%在公路施工前,应当对施工过程进行科学、合理的管理,并在工程后期做好养护工作,保证公路的质量.基于此,对公路施工管理进行了分析,以促进我国公路工程的可持续发展.

  3. Relationship Between Accumulation and Influx of Pollutants in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    The paper discusses the long term mass balance of pollutants in highway ponds. The accumulations of five polycyclic aromatic hydrocarbons (PAHs) and six heavy metals have been measured in eight Danish detention ponds, which receive runoff from highways only. For each pollutant the accumulation has...... been compared to the long-term influx, estimated from short-term measurements of concentrations in highway runoff. The results show that a large proportion of the incoming heavy metals in short-term runoff events has accumulated in the ponds. This is not the case for the toxic organic compounds....... The results also show that the accumulation rates for the heavy metals depend significantly on the relative pond area (pond area divided by catchment area). The conclusion is that the mass balances of heavy metals and PAHs in highway ponds can be estimated with acceptable accuracy from a combination of short...

  4. Photonic Technologies for Ultra-High-Speed Information Highways

    DEFF Research Database (Denmark)

    Bouchoule, S; Lèfevre, R.; Legros, E.;

    1999-01-01

    The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbed....... This paper reviews the current status of 40 Gbit/s TDM components and subsystem technologies achieved in HIGHWAY. The results of HIGHWAY 40 Gbit/s TDM systems and field tests will be reported in a subsequent paper. (C) 1999 Academic Press.......The ACTS project HIGHWAY (AC067) addresses promising ultra-high speed optoelectronic components and system technologies for 40 Gbit/s time-division-multiplexed (TDM) transport systems. Advanced 40 Gbit/s TDM system lab demonstrators are to be realized and tested over installed field fiber testbeds...

  5. Highway vehicle systems contractors coordination meeting. Seventeenth summary report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-01-01

    Separate abstracts was prepared for each of the 62 papers presented at the Contractors' Coordination meeting on highway vehicle systems. One paper had previously appeared in DOE's data base.

  6. Road and Street Centerlines - MO 2010 Highway Patrol Districts (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This is a representation of current Missouri Highway Patrol Districts. Derived from TIGER/Line Files this shapefile and related database files (.dbf) that are an...

  7. Analysis of potential highway routes to Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Sathisan, S.K.; Parentela, E.M.; Lee, M.S. [Univ. of Nevada, Las Vegas, NV (United States)

    1994-12-31

    States have been provided the authority to designate routes for the transport of highway route controlled quantity shipments of radioactive materials. The state of Nevada is currently evaluating alternative routes for such designation. This paper provides a preliminary assessment of potential system impacts of Nevada`s highway route designation for the shipment of High Level Radioactive Waste (HLRW) to the proposed geologic repository at Yucca Mountain, Nevada. A potential route being evaluated by Nevada was used to specify routing constraints for highway shipments to Yucca Mountain. Individual routes were determined for shipments from each origin using the HIGHWAY model for unconstrained and constrained routing scenarios. Results of the analysis indicate that the imposition of the routing constraint would result in increased travel times and shipment distances. These increases range from about 1.25 percent to about 80 percent. However, the magnitude of such increases is highly dependent on the geographic location of the origin.

  8. 46 CFR 393.3 - Marine Highway Corridors.

    Science.gov (United States)

    2010-10-01

    ..., landside infrastructure maintenance savings, improved safety, and added system resiliency. Additional... and performance. (3) Involved Parties. Provide the organizational structure of the parties... infrastructure maintenance costs, safety and system resiliency. Specify if the Marine Highway Corridor represents...

  9. Hanford Reach - Highway 24 Homestead Reclamation Project 2012

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Highway 24 Homestead project is a multi-year reclamation effort in part designed to address habitat degradation and hazardous fuels issues in part caused by past...

  10. Hanford Reach - Highway 24 Homestead Reclamation Project 2013

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Highway 24 Homestead project is a multi-year reclamation effort in part designed to address habitat degradation and hazardous fuels issues in part caused by past...

  11. GRIZZLY Model of Multi-Reactive Species Diffusion, Moisture/Heat Transfer and Alkali-Silica Reaction for Simulating Concrete Aging and Degradation

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hai [Idaho National Lab. (INL), Idaho Falls, ID (United States); Spencer, Benjamin W. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Cai, Guowei [Vanderbilt Univ., Nashville, TN (United States)

    2015-09-01

    Concrete is widely used in the construction of nuclear facilities because of its structural strength and its ability to shield radiation. The use of concrete in nuclear power plants for containment and shielding of radiation and radioactive materials has made its performance crucial for the safe operation of the facility. As such, when life extension is considered for nuclear power plants, it is critical to have accurate and reliable predictive tools to address concerns related to various aging processes of concrete structures and the capacity of structures subjected to age-related degradation. The goal of this report is to document the progress of the development and implementation of a fully coupled thermo-hydro-mechanical-chemical model in GRIZZLY code with the ultimate goal to reliably simulate and predict long-term performance and response of aged NPP concrete structures subjected to a number of aging mechanisms including external chemical attacks and volume-changing chemical reactions within concrete structures induced by alkali-silica reactions and long-term exposure to irradiation. Based on a number of survey reports of concrete aging mechanisms relevant to nuclear power plants and recommendations from researchers in concrete community, we’ve implemented three modules during FY15 in GRIZZLY code, (1) multi-species reactive diffusion model within cement materials; (2) coupled moisture and heat transfer model in concrete; and (3) anisotropic, stress-dependent, alkali-silica reaction induced swelling model. The multi-species reactive diffusion model was implemented with the objective to model aging of concrete structures subjected to aggressive external chemical attacks (e.g., chloride attack, sulfate attack, etc.). It considers multiple processes relevant to external chemical attacks such as diffusion of ions in aqueous phase within pore spaces, equilibrium chemical speciation reactions and kinetic mineral dissolution/precipitation. The moisture

  12. A Practical Model for Deformation Prediction of Highway Subgrade Soils

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper reports a practical constitutive relation for highway subgrade soils. The proposed model is derived based on the laboratory repeated-load testing of four subgrade soils. Statistical parameters generally used in the power model of subgrade permanent strain are expanded into material constants with engineering significance. The constitutional relation reported in this paper can be used in the mechanistic-based pavement design of highway flexible pavements and railroad tracks.

  13. Highway increases concentrations of toxic metals in giant panda habitat.

    Science.gov (United States)

    Zheng, Ying-Juan; Chen, Yi-Ping; Maltby, Lorraine; Jin, Xue-Lin

    2016-11-01

    The Qinling panda subspecies (Ailuropoda melanoleuca qinlingensis) is highly endangered with fewer than 350 individuals inhabiting the Qinling Mountains. Previous studies have indicated that giant pandas are exposed to heavy metals, and a possible source is vehicle emission. The concentrations of Cu, Zn, Mn, Pb, Cr, Ni, Cd, Hg, and As in soil samples collected from sites along a major highway bisecting the panda's habitat were analyzed to investigate whether the highway was an important source of metal contamination. There were 11 sites along a 30-km stretch of the 108th National Highway, and at each site, soil samples were taken at four distances from the highway (0, 50, 100, and 300 m) and at three soil depths (0, 5, 10 cm). Concentrations of all metals except As exceeded background levels, and concentrations of Cu, Zn, Mn, Pb, and Cd decreased significantly with increasing distance from the highway. Geo-accumulation index indicated that topsoil next to the highway was moderately contaminated with Pb and Zn, whereas topsoil up to 300 m away from the highway was extremely contaminated with Cd. The potential ecological risk index demonstrated that this area was in a high degree of ecological hazards, which were also due to serious Cd contamination. And, the hazard quotient indicated that Cd, Pb, and Mn especially Cd could pose the health risk to giant pandas. Multivariate analyses demonstrated that the highway was the main source of Cd, Pb, and Zn and also put some influence on Mn. The study has confirmed that traffic does contaminate roadside soils and poses a potential threat to the health of pandas. This should not be ignored when the conservation and management of pandas is considered.

  14. Permanent Deformation of Highway Subgrade Soils

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Based on a comprehensive review of the literature and preliminary testing performed on a subgrade soil, a testing methodology for repeated load testing was established. This testing protocol was verified using data from subgrade soil. The successful application of this testing protocol on the two subgrade soils proves that it can provide consistent, reliable results. A power model was used to fit the accumulated axial strain over load repetitions with the first hundred cycles excluded from the data set. A number of factors influencing the accumulation of permanent deformation were investigated. The results indicate that confining pressure, load frequency and density are relatively minor contributors to deformation accumulation. Moisture content, deviator stress and first cycle freeze-thaw are major factors governing permanent deformation. The effects of stress history resulting from staged loading are dependent upon the level of applied deviator stress. The interpretation of the rich and consistent deformation data derived from this testing protocol provide valuable insights for transportation engineers relative to the design, construction, operation and maintenance strategy of highway subgrades as well as railway roadbeds.

  15. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  16. Rolling bearing analysis

    CERN Document Server

    Harris, Tedric A

    2001-01-01

    One of the most well-known experts in the field brings cutting-edge research to practitioners in the new edition of this important reference. Covers the improved mathematical calculations for rolling bearing endurance developed by the American Society of Mechanical Engineers and the Society of Lubrication and Tribology Engineers. Updated with new material on Condition-Based Maintenance, new testing methods, and new bearing materials.

  17. My Little Teddy Bear

    Institute of Scientific and Technical Information of China (English)

    钱佳楠

    2005-01-01

    @@ As Valentine's Day came closer,every shop was full of colourful gifts such as cookies in the shape of heart, chocolates,Teddy Bears and so on.When I step into a shop on February 14th,I felt most lonely as I was alone.With mv eves fixed on a lovely Teddy Bear, I wished that someone could send me this stuffed toy.

  18. Sand harm in taklimakan Desert highway and sand control

    Institute of Scientific and Technical Information of China (English)

    HANZhiwen; WANGTao; SUNQingwei; DONGZhibao; WANGXunming

    2003-01-01

    Reputed as a wonderful achievement of the world’s highway construction history,the Taklimakan Desert highway is nor facing serious sand drift encroachment problems due to its 447-km-long passage of sand sea consisting of crescent dunes,barchan chains,compound transverse dune ridges and complex megadunes.To solve some technical problems in the protection of the highway from sang drift encroachment,desert experts have been conducting the theoretical and applied studies on sand movement laws;causes,severities and time-space differentiation of sand drift damages;and control ways including mechanical,chemical and biological measures.In this paper the authors give an overall summry on the research contents and recent progress in the control of sand drift damages in China and hold that the theoretical researc results and practices in the prevention of sand drift encroachment on the cross-desert highway represnt a breakthrough and has an cpoch-making significance.Since the construction of protective forest along the cross-desert highway requires large amount of ground water,what will be its environmental consequence and whether it can effectively halt sand drift encroachment on the highway forever are the questions to be studied urgently.

  19. Magnetic Bearing Consumes Low Power

    Science.gov (United States)

    Studer, P. A.

    1982-01-01

    Energy-efficient linear magnetic bearing maintains a precise small separation between its moving and stationary parts. Originally designed for cryogenic compressors on spacecraft, proposed magnetic bearing offers an alternative to roller or gas bearing in linear motion system. Linear noncontacting bearing operates in environments where lubricants cannot be used.

  20. Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

    Science.gov (United States)

    Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

    2014-01-01

    Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

  1. Tribology of alternative bearings.

    Science.gov (United States)

    Fisher, John; Jin, Zhongmin; Tipper, Joanne; Stone, Martin; Ingham, Eileen

    2006-12-01

    The tribological performance and biological activity of the wear debris produced has been compared for highly cross-linked polyethylene, ceramic-on-ceramic, metal-on-metal, and modified metal bearings in a series of in vitro studies from a single laboratory. The functional lifetime demand of young and active patients is 10-fold greater than the estimated functional lifetime of traditional polyethylene. There is considerable interest in using larger diameter heads in these high demand patients. Highly cross-linked polyethylene show a four-fold reduction in functional biological activity. Ceramic-on-ceramic bearings have the lowest wear rates and least reactive wear debris. The functional biological activity is 20-fold lower than with highly cross-linked polyethylene. Hence, ceramic-on-ceramic bearings address the tribological lifetime demand of highly active patients. Metal-on-metal bearings have substantially lower wear rates than highly cross-linked polyethylene and wear decreases with head diameter. Bedding in wear is also lower with reduced radial clearance. Differential hardness ceramic-on-metal bearings and the application of ceramic-like coatings reduce metal wear and ion levels.

  2. Off-Highway Gasoline Consuption Estimation Models Used in the Federal Highway Administration Attribution Process: 2008 Updates

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Ho-Ling [ORNL; Davis, Stacy Cagle [ORNL

    2009-12-01

    This report is designed to document the analysis process and estimation models currently used by the Federal Highway Administration (FHWA) to estimate the off-highway gasoline consumption and public sector fuel consumption. An overview of the entire FHWA attribution process is provided along with specifics related to the latest update (2008) on the Off-Highway Gasoline Use Model and the Public Use of Gasoline Model. The Off-Highway Gasoline Use Model is made up of five individual modules, one for each of the off-highway categories: agricultural, industrial and commercial, construction, aviation, and marine. This 2008 update of the off-highway models was the second major update (the first model update was conducted during 2002-2003) after they were originally developed in mid-1990. The agricultural model methodology, specifically, underwent a significant revision because of changes in data availability since 2003. Some revision to the model was necessary due to removal of certain data elements used in the original estimation method. The revised agricultural model also made use of some newly available information, published by the data source agency in recent years. The other model methodologies were not drastically changed, though many data elements were updated to improve the accuracy of these models. Note that components in the Public Use of Gasoline Model were not updated in 2008. A major challenge in updating estimation methods applied by the public-use model is that they would have to rely on significant new data collection efforts. In addition, due to resource limitation, several components of the models (both off-highway and public-us models) that utilized regression modeling approaches were not recalibrated under the 2008 study. An investigation of the Environmental Protection Agency's NONROAD2005 model was also carried out under the 2008 model update. Results generated from the NONROAD2005 model were analyzed, examined, and compared, to the extent that

  3. Lidar-Based Mapping of Late Quaternary Faulting Along the Grizzly Valley Fault, Walker Lane Seismic Belt, California

    Science.gov (United States)

    Hitchcock, C. S.; Hoirup, D. F.; Barry, G.; Pearce, J.; Glick, F.

    2012-12-01

    The Grizzly Valley fault (GVF) is located within the northern Walker Lane, a zone of right-lateral shear between the Sierra Nevada and the Basin and Range in Plumas County. The GVF extends southeasterly from near Mt. Ingalls along the eastern side of Lake Davis. It may partially connect with the Hot Creek fault within Sierra Valley and extend south to Loyalton with an overall approximate length of 50 km. Comparison of high-resolution topography developed from LiDAR data with published bedrock geologic mapping documents the presence of geomorphic features that provide information on fault activity of the GVF. Field mapping verified tectonically deformed and offset late Quaternary surfaces identified on bare-earth LiDAR imagery across the GVF within glacial deposits on the eastern margin of Lake Davis, and alluvial deposits in Sierra Valley. Along the GVF, conspicuous geomorphic and hydrologic features include scarps in alluvial surfaces, elongated depressions aligned with adjacent linear escarpments, truncated bedrock spurs, closed depressions, linear swales, right-lateral deflections of creeks and river courses, and shutter ridges, as well as springs and linear seeps consistent with right-lateral strike-slip faulting. The discontinuous nature of observed fault traces combined with the apparent down-to-the-west offset of alluvial surfaces at the southern and northern ends of the eastern margin of Lake Davis are consistent with a broad bend or step over in the fault. Scarp profiles of apparently faulted surfaces extracted from LiDAR data document vertical offsets of up to 14 m. Our study suggest that the GVF is an oblique, right-lateral fault that has been active in the late Quaternary. This study complements on-going investigations by DWR to assess the impact of seismic hazards on State Water Project infrastructure.

  4. Radial Halbach Magnetic Bearings

    Science.gov (United States)

    Eichenberg, Dennis J.; Gallo, Christopher A.; Thompson, William K.

    2009-01-01

    Radial Halbach magnetic bearings have been investigated as part of an effort to develop increasingly reliable noncontact bearings for future high-speed rotary machines that may be used in such applications as aircraft, industrial, and land-vehicle power systems and in some medical and scientific instrumentation systems. Radial Halbach magnetic bearings are based on the same principle as that of axial Halbach magnetic bearings, differing in geometry as the names of these two types of bearings suggest. Both radial and axial Halbach magnetic bearings are passive in the sense that unlike most other magnetic bearings that have been developed in recent years, they effect stable magnetic levitation without need for complex active control. Axial Halbach magnetic bearings were described in Axial Halbach Magnetic Bearings (LEW-18066-1), NASA Tech Briefs, Vol. 32, No. 7 (July 2008), page 85. In the remainder of this article, the description of the principle of operation from the cited prior article is recapitulated and updated to incorporate the present radial geometry. In simplest terms, the basic principle of levitation in an axial or radial Halbach magnetic bearing is that of the repulsive electromagnetic force between (1) a moving permanent magnet and (2) an electric current induced in a stationary electrical conductor by the motion of the magnetic field. An axial or radial Halbach bearing includes multiple permanent magnets arranged in a Halbach array ("Halbach array" is defined below) in a rotor and multiple conductors in the form of wire coils in a stator, all arranged so the rotary motion produces an axial or radial repulsion that is sufficient to levitate the rotor. A basic Halbach array (see Figure 1) consists of a row of permanent magnets, each oriented so that its magnetic field is at a right angle to that of the adjacent magnet, and the right-angle turns are sequenced so as to maximize the magnitude of the magnetic flux density on one side of the row while

  5. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  6. The Little Bear

    Institute of Scientific and Technical Information of China (English)

    林战峰; 乐伟国

    2007-01-01

    @@ 一、故事内容 A little bear has a magic stick.It can make his wishes come true. One day,the little bear is walking in the forest.He sees a bird.It is flying in the sky.It has two beautiful wings."I want two beautiful wings.I wish I can fly like a bird,"he says to the magic stick.Two beautiful wings come out from his back and he can fly like a bird now.He is very happy.

  7. Modular gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  8. Prizing on Paths: A PTAS for the Highway Problem

    CERN Document Server

    Grandoni, Fabrizio

    2010-01-01

    In the highway problem, we are given an n-edge line graph (the highway), and a set of paths (the drivers), each one with its own budget. For a given assignment of edge weights (the tolls), the highway owner collects from each driver the weight of the associated path, when it does not exceed the budget of the driver, and zero otherwise. The goal is choosing weights so as to maximize the profit. A lot of research has been devoted to this apparently simple problem. The highway problem was shown to be strongly NP-hard only recently [Elbassioni,Raman,Ray-'09]. The best-known approximation is O(\\log n/\\log\\log n) [Gamzu,Segev-'10], which improves on the previous-best O(\\log n) approximation [Balcan,Blum-'06]. In this paper we present a PTAS for the highway problem, hence closing the complexity status of the problem. Our result is based on a novel randomized dissection approach, which has some points in common with Arora's quadtree dissection for Euclidean network design [Arora-'98]. The basic idea is enclosing the ...

  9. A speed-flow relationship model of highway traffic flow

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; LI Wei; REN Gang

    2005-01-01

    In the view that the generally used speed-flow relationship model is insufficient in the traffic analysis under over-saturated conditions, this paper first establishes the theoretical models of speed flow relationship for each highway class based upon a large number of traffic data collected from the field. Then by analyzing the traffic flow dissipation mechanism under peak hour over-saturated traffic conditions, the speed flow relationship model structures for each highway class are reviewed under different traffic load conditions. Through curve-fitting of large numbers of observed data, functional equations of general speed-flow relationship models for each highway class under any traffic load conditions are established. The practical model parameters for each highway class under different design speeds are also put forward. This model is successful in solving the speed-forecasting problem of the traffic flow under peak hour over-saturated conditions. This provides the theoretical bases for the development of projects related to highway network planning, economic analysis, etc.

  10. Deicing chemicals as source of constituents of highway runoff

    Science.gov (United States)

    Granato, G.E.

    1996-01-01

    The dissolved major and trace constituents of deicing chemicals as a source of constituents in highway runoff must be quantified for interpretive studies of highway runoff and its effects on surface water and groundwater. Dissolved constituents of the deicing chemicals-sodium chloride, calcium chloride, and premix (a mixture of sodium and calcium chloride)-were determined by analysis of salt solutions created in the laboratory and are presented as mass ratios to chloride. Deicing chemical samples studied are about 98 and 97 percent pure sodium chloride and calcium chloride, respectively: however, each has a distinct major and trace ion constituent signature. The greatest impurity in sodium chloride road sail samples was sulfate, followed by calcium, potassium, bromide, vanadium, magnesium, fluoride, and other constituents with a ratio to chloride of less than 0.0001 by mass. The greatest impurity in the calcium chloride road salt samples was sodium, followed by potassium, sulfate, bromide, silica, fluoride. strontium, magnesium, and other constituents with a ratio to chloride of less than 0.0001 by mass. Major constituents of deicing chemicals in highway runoff may account for a substantial source of annual chemical loads. Comparison of estimated annual loads and first flush concentrations of deicing chemical constituents in highway runoff with those reported in the literature indicate that although deicing chemicals are not a primary source of trace constituents, they are not a trivial source, either. Therefore, deicing chemicals should be considered as a source of many major and trace constituents in highway and urban runoff.

  11. Accident prediction model for public highway-rail grade crossings.

    Science.gov (United States)

    Lu, Pan; Tolliver, Denver

    2016-05-01

    Considerable research has focused on roadway accident frequency analysis, but relatively little research has examined safety evaluation at highway-rail grade crossings. Highway-rail grade crossings are critical spatial locations of utmost importance for transportation safety because traffic crashes at highway-rail grade crossings are often catastrophic with serious consequences. The Poisson regression model has been employed to analyze vehicle accident frequency as a good starting point for many years. The most commonly applied variations of Poisson including negative binomial, and zero-inflated Poisson. These models are used to deal with common crash data issues such as over-dispersion (sample variance is larger than the sample mean) and preponderance of zeros (low sample mean and small sample size). On rare occasions traffic crash data have been shown to be under-dispersed (sample variance is smaller than the sample mean) and traditional distributions such as Poisson or negative binomial cannot handle under-dispersion well. The objective of this study is to investigate and compare various alternate highway-rail grade crossing accident frequency models that can handle the under-dispersion issue. The contributions of the paper are two-fold: (1) application of probability models to deal with under-dispersion issues and (2) obtain insights regarding to vehicle crashes at public highway-rail grade crossings.

  12. Application and challenges of big data in quality monitoring of highway engineering

    Science.gov (United States)

    Xiao, Xianglin; Zhou, Chunrong

    2017-03-01

    Generation of big data brings opportunities and challenges to quality monitoring technologies of highway engineering. Big data of highway engineering quality monitoring is featured by typical "4V" characteristics. In order to deeply analyze application of big data in quality monitoring of highway engineering, the paper discusses generation, processing processes, key technologies as well as other aspects of big data of highway engineering quality monitoring. The paper analyzes storage structure, computing courses and data visualized processing processes of the big data of highway engineering quality monitoring and points out the problems and challenges encountered by application of big data in quality monitoring of highway engineering.

  13. External Costs to Parties Involved in Highway Traffic Accidents: The Perspective of Highway Users

    Directory of Open Access Journals (Sweden)

    Rong-Chang Jou

    2015-06-01

    Full Text Available This study explores highway travellers’ willingness to pay (WTP for external costs caused by traffic accidents. There are a number of further external costs, the paper focuses on two externalities: air pollution and time delays. Data collection was performed using the face-to-face survey method, and the surveys were carried out at highway rest areas. Air pollution and time delays were divided into three levels of severity (light, moderate and severe to obtain the interviewees’ WTP according to each level of severity. The result of this study demonstrates that there are many samples with zero WTP because penalties for pollution caused by traffic accidents are not currently enforced in Taiwan. Thus, the spike model was adopted in this study to overcome any estimation error that might be caused by excessive NT$0 WTP samples. The results show that variables such as age, education, income and willingness to participate in activities of environmental protection have a positive effect on WTP for air pollution, whereas variables such as occupation, travel purpose, traveller identity, travel time and travel distance have a significantly positive effect on WTP for time delays. WTP for nitrogen dioxide (NO2 is NT$8862–11,502/metric ton (US$1 = NT$30 and WTP for carbon dioxide (CO2 is NT$1070–2693/metric ton. Moreover, WTP for time delays is NT$960–1320/h. The findings of this study not only demonstrate WTP for air pollution and time delays in the minds of parties to traffic accidents but also help to provide agencies with a basis to formulate applicable penalties in the future.

  14. Hybrid superconductor magnet bearings

    Science.gov (United States)

    Chu, Wei-Kan

    1995-01-01

    Hybrid superconductor magnet bearings (HSMB's) utilize high temperature superconductors (HTS's) together with permanent magnets to form a frictionless interface between relatively rotating parts. They are low mass, stable, and do not incur expenditure of energy during normal operation. There is no direct physical contact between rotor and stator, and hence there is no wear and tear. However, just as any other applications of HTS's, it requires a very cold temperature to function. Whereas this might be perceived as a disadvantage on earth, it is of no great concern in space or on the moon. To astronomers, the moon is an excellent site for an observatory, but the cold and dusty vacuum environment on the moon precludes the use of mechanical bearings on the telescope mounts. Furthermore, drive mechanisms with very fine steps, and hence bearings with extremely low friction are needed to track a star from the moon, because the moon rotates very slowly. All aspects considered, the HSMB is about the only candidate that fits in naturally. Here, we present a design for one such bearing, capable of supporting a telescope that weighs about 3 lbs on Earth.

  15. Silver Bear for Screenplay

    Institute of Scientific and Technical Information of China (English)

    LIU YUNYUN

    2010-01-01

    @@ Chinese director Wang Quan'an won the Silver Bear Prize at the 60th Berlin International Film Festival that lasted during February 11 to 21 tor the best screenplay for his movie Apart Together.The film also opened the festival.

  16. The highway capacity manual a conceptual and research history

    CERN Document Server

    Roess, Roger P

    2014-01-01

    Since 1950, the Highway Capacity Manual has been a standard used in the planning, design, analysis, and operation of virtually any highway traffic facility in the United States. It has also been widely used abroad, and has spurred the development of similar manuals in other countries. The twin concepts of capacity and level of service have been developed in the manual, and methodologies have been presented that allow highway traffic facilities to be designed on a common basis, and allow for the analysis of operational quality under various traffic demand scenarios. The manual also addresses related pedestrian, bicycle, and transit issues.   This book details the fundamental development of the concepts of capacity and level of service, and of the specific methodologies developed to describe them over a wide range of facility types. The book is comprised of two volumes. Volume 1 (this book) focuses on the development of basic principles, and their application to uninterrupted flow facilities: freeways, multila...

  17. Design and analysis of highway windmill electric generation

    Directory of Open Access Journals (Sweden)

    Suresh Mashyal

    2014-07-01

    Full Text Available The work deals with designing a portable highway wind turbine, which is to be contribute towards the global trend in wind energy production in a feasible way. Wind turbines are traditionally employed in rural areas; the main goal the work is to design a wind turbine that can be used in cities. In particular, the turbines will use the wind draft created by vehicles on the highway to generate electricity. The idea is to offset the amount of pollution created by burning fossil fuels by introducing a potential source of clean energy. As the automobiles moves from highways/expressways, there is a creation of pressure column on both the sides of the road. This pressure column is created due to imbalance of high pressure/low pressure energy band created by the automobiles. Due to this pressure band wind flow and create pressure thrust. The pressure thrust is sufficient to generate electricity through designed wind turbine.

  18. Abandoned Highway Sections: an Opportunity for Requalification Landscape Projects

    Directory of Open Access Journals (Sweden)

    Lucia Moretti

    2014-12-01

    Full Text Available With technology constantly improving, modern highways can nowadays be built through terrains where construction used to be either technically infeasible or too costly. While this results in faster connections and shorter commuting times, it leaves the abandoned historic routes behind without any use. This workshop was aimed at developing solutions for the requalification of abandoned highway sections, focusing on the example of the Autostrada del Sole which bypasses the little town of Vado, Bologna. A concept of converting the section into a Sole Park - a park which offers both relaxation and amusement elements - was developed in order to attract visitors from the neighboring villages and the high-speed highway. Within this context, potential locations for lookouts were identified, giving stunning vistas of the Tuscan-Emilian landscape.

  19. Magnetic bearings for cryogenic turbomachines

    Science.gov (United States)

    Iannello, Victor; Sixsmith, Herbert

    1991-01-01

    Magnetic bearings offer a number of advantages over gas bearings for the support of rotors in cryogenic turboexpanders and compressors. Their performance is relatively independent of the temperature or pressure of the process gas for a large range of conditions. Active magnetic bearing systems that use capacitive sensors have been developed for high speed compressors for use in cryogenic refrigerators. Here, the development of a magnetic bearing system for a miniature ultra high speed compressor is discussed. The magnetic bearing has demonstrated stability at rotational speeds exceeding 250,000 rpm. This paper describes the important features of the magnetic bearing and presents test results demonstrating its performance characteristics.

  20. International Contribution to the Highway Agency's Bridge Related Research

    DEFF Research Database (Denmark)

    Nowak, A. S.; Thoft-Christensen, Palle

    The objective of this paper is to summarize recent contributions of international experts to the research program sponsored by the Highways Agency. An efficient management of existing bridges requires methodology for an accurate evaluation of the actual loads and load carrying capacity and predic......The objective of this paper is to summarize recent contributions of international experts to the research program sponsored by the Highways Agency. An efficient management of existing bridges requires methodology for an accurate evaluation of the actual loads and load carrying capacity...... of reliability models for analysis of bridges subjected to corrosion and fatigue, and reliability-based optimization of maintenance strategies for bridges....

  1. Brief Analysis on Highway Construction and Urban Development

    Institute of Scientific and Technical Information of China (English)

    Chen; XU; Zhongxiang; YU

    2013-01-01

    On the basis of studying influence of means of transportation on urban distribution and form,this paper focuses on influence of highway on modern urban areas. Results show that construction of highway accelerates urbanization,forms organic traffic network connecting large, medium and small cities and towns,and promotes development of modern urban agglomeration. Finally,it presents rational ideas of strengthening planning,integrating urban and rural development,preventing blind expansion of urban areas,and building ecological and garden cities.

  2. Magnetic bearings grow more attractive

    Science.gov (United States)

    1993-10-01

    Advances in materials and electronics have enabled designers to devise simpler, smaller magnetic bearings. As a result, costs have dropped, widening the applications for these very-low-friction devices. Avcon (Advanced Controls Technology) has patented a permanent-magnet bias actively controlled bearing. Here high-energy rare earth permanent-magnet materials supply the basic bearing load levitation, while servo-driven electromagnets generate stabilization and centering forces for motion contol. Previous heavy-duty magnetic bearings used electromagnets entirely for suspension and control, which led to large bearings and control systems with higher power requirements. Avcon has developed several types of permanent-magnet bias bearings. The simplest is the radial repulsion bearing. Avcon's homopolar permanent-magnet bias active bearing is the most versatile of the company's designs.

  3. 40 CFR 1051.105 - What are the exhaust emission standards for off-highway motorcycles?

    Science.gov (United States)

    2010-07-01

    ... gas-fueled off-highway motorcycles: NMHC emissions. (2) Alcohol-fueled off-highway motorcycles: THCE... operating life from advertisements or other marketing materials for any vehicles in the engine family....

  4. Government Risk-Bearing

    CERN Document Server

    1993-01-01

    The u.s. government bulks large in the nation's financial markets. The huge volume of government-issued and -sponsored debt affects the pricing and volume ofprivate debt and, consequently, resource allocation between competing alternatives. What is often not fully appreciated is the substantial influence the federal government wields overresource allocation through its provisionofcreditandrisk-bearing services to the private economy. Because peopleand firms generally seekto avoid risk, atsomeprice they are willing to pay another party to assume the risk they would otherwise face. Insurance companies are a class of private-sector firms one commonly thinks of as providing these services. As the federal government has expanded its presence in the U.S. economy during this century, it has increasingly developed programs aimed at bearing risks that the private sector either would not take on at any price, or would take on but atapricethoughtto besogreatthatmostpotentialbeneficiarieswouldnotpurchase the coverage. To...

  5. Centrifugally decoupling touchdown bearings

    Science.gov (United States)

    Post, Richard F

    2014-06-24

    Centrifugally decoupling mechanical bearing systems provide thin tensioned metallic ribbons contained in a support structure. This assembly rotates around a stationary shaft being centered at low speeds by the action of the metal ribbons. Tension springs are connected on one end to the ribbons and on the other end to the support structure. The ribbons pass through slots in the inner ring of the support structure. The spring preloading thus insures contact (or near-contact) between the ribbons and the shaft at rotation speeds below the transition speed. Above this speed, however, the centrifugal force on the ribbons produces a tensile force on them that exceeds the spring tensile force so that the ribbons curve outward, effectively decoupling them from mechanical contact with the shaft. They still remain, however, in position to act as a touchdown bearing in case of abnormally high transverse accelerations.

  6. Trend of Self-bearing Motors(Magnetic Bearings)

    OpenAIRE

    上野, 哲; Satoshi, UENO; 立命館大学

    2008-01-01

    This paper introduces a trend of a self-bearing motor that combines the functions of a motor and active magnetic bearing. The self-bearing motor has advantages, such as miniaturization, low cost, and high speed rotation in addition to the advantages of the active magnetic bearing. Various types of self-bearing motors such as a radial type, axial type, permanent magnet type, induction type, and reluctance type, have been proposed. In this paper, technologies and applications of the self-bearin...

  7. Leakage-free journal bearings

    Science.gov (United States)

    Pinkus, O.; Etsion, I.

    1976-01-01

    A new concept of a journal bearing is developed which prevents side leakage of the lubricant, thus eliminating the need for sealing and collecting this leakage. The cooling of the bearing is accomplished by the prevailing circumferential flow. An analysis is performed and solutions are given for the bearing geometries and inlet pressures required to achieve the above purpose.

  8. Career Counseling and the Information Highway: Heeding the Road Signs.

    Science.gov (United States)

    O'Halloran, Theresa M.; Fahr, Alicia V.; Keller, Jenny R.

    2002-01-01

    Traveling the "information highway" in the process of career counseling or providing career counseling services via the Internet pose additional challenges for counselors. The authors use current ethical guidelines to guide discussion of, and possible resolutions to, challenges posed by incorporating the Internet into career counseling. (Contains…

  9. 78 FR 71715 - Amendments to Highway Safety Program Guidelines

    Science.gov (United States)

    2013-11-29

    ...), James Stowe, and the University of North Carolina Highway Safety Research Center (UNC). The majority of... Board (NTSB), New York State Office for the Aging (NYSOA), University of North Carolina (UNC), as well... autonomy possible; Establish a Medical Advisory Board (MAB), consisting of a range of medical...

  10. 46 CFR 393.4 - Marine Highway Projects.

    Science.gov (United States)

    2010-10-01

    .... Include the projected savings in life-cycle costs of publicly maintained infrastructure. (vi) Business... avoided, infrastructure construction or expansion deferred). Timeliness factor. Is the project on track... 46 Shipping 8 2010-10-01 2010-10-01 false Marine Highway Projects. 393.4 Section 393.4 Shipping...

  11. assessment of traffic flow on enugu highways using speed density ...

    African Journals Online (AJOL)

    HOD

    This research provides practical application for speed estimation, construction, maintenance and optimization of the highways using the speed-density models which will enhance traffic ... engineering. .... machines without actually taking physical field traffic .... Federal Road Safety Corps, Enugu State Command, 2015.

  12. Wind Effects on Retention Time in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    2007-01-01

    The paper presents results from an experimental and numerical study of wind-induced flows and transportation patterns in highway wet detention ponds. The study presented here is part of a general investigation on road runoff and pollution in respect to wet detention ponds. The objective is to eva......-uniform wind field distributions are not significant to this study....

  13. Managing Highway Maintenance: Budget Preparation, Unit 9, Level 3.

    Science.gov (United States)

    Federal Highway Administration (DOT), Washington, DC. Offices of Research and Development.

    Part of the series "Managing Highway Maintenance," the unit describes the essential steps in developing a maintenance budget, or performance budget, based on the work to be done. It is designed for field engineers and supervisors who assist department officials in preparing work programs and budgets. The format is a programed,…

  14. Managing Highway Maintenance--Training Guide and Catalog.

    Science.gov (United States)

    Burke, Clyde A.

    A model curriculum is reported for training personnel who are responsible for managing highway maintenance field operations. The training is organized and sequenced by five broad areas--management problems, management by objective, work planning, work control and management systems. In each area, one or more training units are provided for each of…

  15. 23 CFR 470.107 - Federal-aid highway systems.

    Science.gov (United States)

    2010-04-01

    ... intermodal transportation facilities and other major travel destinations; meet national defense requirements; and serve interstate and interregional travel. All routes on the Interstate System are a part of the... consultation with appropriate Federal agencies and the States. The STRAHNET includes highways which...

  16. Feasibility of shoulder use for highway work zone optimization

    Directory of Open Access Journals (Sweden)

    Bo Du

    2014-08-01

    Full Text Available Highway maintenance, often requiring lane closure, is very expensive in terms of the costs associated with transportation agencies (i. e. work zone setups and road users (i. e. delay. Longer work zones tend to increase the user delay but will be efficient because of fewer repeated setups. To increase road capacity and mitigate congestion impact for a short-term work zone, temporary shoulder use may be applied. This study develops an analytical model to optimize work zone length on a multi-lane highway considering time-varying traffic volume and road capacity affected by light condition, heavy vehicle percentage, and lane width. The results can be used to evaluate the work zone impact (i. e. delay and cost and assist engineers/planners to prepare and develop a cost-effective highway maintenance plan. A case study for a highway work zone in New Jersey has been conducted, in which the optimized solution is found. A guideline of using road shoulder under various circumstances is developed.

  17. Wind Effects on Retention Time in Highway Ponds

    DEFF Research Database (Denmark)

    Bentzen, Thomas Ruby; Larsen, Torben; Rasmussen, Michael R.

    2008-01-01

    is to evaluate the quality of long term simulations based on historical rain series of the pollutant discharges from roads and highways. The idea of this paper is to evaluate the effects of wind on the retention time and compare the retention time for the situation of a spatial uniform wind shear stress...

  18. Alternative energy sources for non-highway transportation. Appendices

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    A planning study was made for DOE on alternate fuels for non-highway transportation (aircraft, rail, marine, and pipeline). The study provides DOE with a recommendation of what alternate fuels may be of interest to non-highway transportation users from now through 2025 and recommends R and D needed to allow non-petroleum derived fuels to be used in non-highway transportation. Volume III contains all of the references for the data used in the preliminary screening and is presented in 4 subvolumes. Volume IIIA covers the background information on the various prime movers used in the non-highway transportation area, the physical property data, the fuel-prime mover interaction and a review of some alternate energy forms. Volume IIIB covers the economics of producing, tranporting, and distributing the various fuels. Volume IIIC is concerned with the environment issues in production and use of the fuels, the energy efficiency in use and production, the fuel logistics considerations, and the overall ratings and selection of the fuels and prime movers for the detailed evaluation. Volume IIID covers the demand-related issues.

  19. Highway Expenditures and Associated Customer Satisfaction: A Case Study

    Directory of Open Access Journals (Sweden)

    Alexander Paz

    2016-01-01

    Full Text Available This study analyzes the satisfaction of the Nevadans with respect to their highway transportation system and the corresponding expenditures of Nevada Department of Transportation (NDOT. A survey questionnaire was designed to capture the opinions of the Nevadans (customers about a number of characteristics of their transportation system. Data from the financial data warehouse of the NDOT was used to evaluate expenditures. Multinomial probit models were estimated to study the correlations between customers’ opinion and the government expenditures in transportation. The results indicate the customer satisfaction is decreasing with respect to traffic safety throughout Northwestern and Southern Nevada highways. In addition, users of Northwestern highways are more likely to be satisfied, compared to their counterparts, with increasing construction spending to reduce the time taken to complete construction projects. In Southern Nevada highways, customers’ satisfaction increases with the expenditures associated with reduction of congestion. These insights are examples of the conclusions that were obtained as a consequence of simultaneously considering customer satisfaction and the corresponding expenditures in transportation.

  20. Engineering metabolic highways in Lactococci and other lactic acid bacteria

    NARCIS (Netherlands)

    Vos, de W.M.; Hugenholtz, J.

    2004-01-01

    Lactic acid bacteria (LAB) are widely used in industrial food fermentations and are receiving increased attention for use as cell factories for the production of food and pharmaceutical products. Glycolytic conversion of sugars into lactic acid is the main metabolic highway in these Gram-positive

  1. Investigation of the Seismic Performance of Reinforced Highway Embankments

    Science.gov (United States)

    Toksoy, Y. S.; Edinçliler, A.

    2014-12-01

    Despite the fact that highway embankments are highly prone to earthquake induced damage, there are not enough studies in the literature concentrated on improving the seismic performance of highway embankments. Embankments which are quite stable under static load conditions can simply collapse during earthquakes due to the destructive seismic loading. This situation poses a high sequence thread to the structural integrity of the embankment, service quality and serviceability. The objective of this study is to determine the effect of the geosynthetic reinforcement on the seismic performance of the highway embankments and evaluate the seismic performance of the geotextile reinforced embankment under different earthquake motions. A 1:50 scale highway embankment model is designed and reinforced with geosynthetics in order to increase the seismic performance of the embankment model. A series of shaking table tests were performed for the identical unreinforced and reinforced embankment models using earthquake excitations with different characteristics. The experimental results were evaluated comparing the unreinforced and reinforced cases. Results revealed that reinforced embankment models perform better seismic performance especially under specificied ground excitations used in this study. Also, the prototype embankment was numerically modelled. It is seen that similar seismic behavior trend is obtained in the finite element simulations.

  2. Driving simulator research on safe highway design and operation

    NARCIS (Netherlands)

    Horst, A.R.A. van der; Hogema, J.H.

    2011-01-01

    With increasing traffic demands and various attempts to get maximum performance out of the road traffic system, the driving task is becoming more and more complex, and the more important it is to consider the human factor in highway design and operation. Successful introduction of new driver support

  3. Traffic control and intelligent vehicle highway systems: a survey

    NARCIS (Netherlands)

    Baskar, L.D.; Schutter, B. de; Hellendoorn, J.; Papp, Z.

    2011-01-01

    Traffic congestion in highway networks is one of the main issues to be addressed by today's traffic management schemes. Automation combined with the increasing market penetration of on-line communication, navigation and advanced driver assistance systems will ultimately result in intelligent vehicle

  4. Basic Course in Highway Traffic Records; Course Guide.

    Science.gov (United States)

    National Highway Traffic Safety Administration (DOT), Washington, DC.

    The twelve-part course is structured on a modular basis to allow the various topical areas and units of instruction to satisfy differing training requirements of state and local agencies which vary from state to state. It is specifically designed to provide guidence to state highway safety program management personnel, traffic records…

  5. A Functional Architecture For Automated Highway Traffic Planning

    OpenAIRE

    Tsao, H. S. Jacob

    1994-01-01

    This report defines an architecture for Automated Highway System (AHS) capacity-optimizing traffic planning functions. It identifies major traffic planning functions useful for optimizing the capacity of one or more major AHS operating scenarios and organizes them in a robust architecture that is modular, hierarchical, complete, expandable and integratable.

  6. Colleges and Universities Highway Traffic and Safety Centers.

    Science.gov (United States)

    Aaron, James E., Ed.; Ritzel, Dale O., Ed.

    After consideration of the organizing of university safety centers and the growth and role of such centers in the future, descriptions are presented of the activities and practices in each of 16 existing college and university highway traffic and safety centers. Information is presented regarding center objectives, programs, staff composition,…

  7. Engineering metabolic highways in Lactococci and other lactic acid bacteria

    NARCIS (Netherlands)

    Vos, de W.M.; Hugenholtz, J.

    2004-01-01

    Lactic acid bacteria (LAB) are widely used in industrial food fermentations and are receiving increased attention for use as cell factories for the production of food and pharmaceutical products. Glycolytic conversion of sugars into lactic acid is the main metabolic highway in these Gram-positive ba

  8. 26 CFR 48.6421-0 - Off-highway business use.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Off-highway business use. 48.6421-0 Section 48... Special Application to Retailers and Manufacturers Taxes § 48.6421-0 Off-highway business use. For purposes of the regulations under section 6421, after March 31, 1983, the term “off-highway business use...

  9. 26 CFR 48.6427-0 - Off-highway business use.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Off-highway business use. 48.6427-0 Section 48... Special Application to Retailers and Manufacturers Taxes § 48.6427-0 Off-highway business use. For purposes of the regulations under section 6427, after March 31, 1983, the term “off-highway business use...

  10. The Impacts of Highway Expansion on Population Change: An Integrated Spatial Approach

    Science.gov (United States)

    Chi, Guangqing

    2010-01-01

    The effects of highways on transforming human society and promoting population change have been investigated in several disciplines, including geography, sociology, economics, and planning. Currently, the primary highway construction activity in the nation is highway expansion; however, this expansion has not been the focus of much of the existing…

  11. An integrated model for the Environmental Impact Assessment of Highways in China

    DEFF Research Database (Denmark)

    Cai, Hao

    2011-01-01

    In China, environmental issues caused by construction and operation of highway catch more and more attention, and thus environmental impact assessment of highway has become an important part of feasibility study. According to the Specifications for Environmental Impact Assessment of Highways...

  12. 49 CFR 234.261 - Highway traffic signal pre-emption.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Highway traffic signal pre-emption. 234.261... Maintenance, Inspection, and Testing Inspections and Tests § 234.261 Highway traffic signal pre-emption. Highway traffic signal pre-emption interconnections, for which a railroad has maintenance...

  13. 77 FR 14857 - Final Federal Agency Actions on Proposed Highway in North Carolina

    Science.gov (United States)

    2012-03-13

    ... addresses provided above. The FEIS and ROD can be viewed and downloaded from the project Web site at www... Hoops, Major Projects Engineer, Federal Highway Administration, Raleigh, North Carolina. BILLING CODE... Federal Highway Administration Final Federal Agency Actions on Proposed Highway in North Carolina AGENCY...

  14. Temporary Losses of Highway Capacity and Impacts on Performance

    Energy Technology Data Exchange (ETDEWEB)

    Chin, S.M.

    2002-07-31

    Traffic congestion and its impacts significantly affect the nation's economic performance and the public's quality of life. In most urban areas, travel demand routinely exceeds highway capacity during peak periods. In addition, events such as crashes, vehicle breakdowns, work zones, adverse weather, and suboptimal signal timing cause temporary capacity losses, often worsening the conditions on already congested highway networks. The impacts of these temporary capacity losses include delay, reduced mobility, and reduced reliability of the highway system. They can also cause drivers to re-route or reschedule trips. Prior to this study, no nationwide estimates of temporary losses of highway capacity had been made by type of capacity-reducing event. Such information is vital to formulating sound public policies for the highway infrastructure and its operation. This study is an initial attempt to provide nationwide estimates of the capacity losses and delay caused by temporary capacity-reducing events. The objective of this study was to develop and implement methods for producing national-level estimates of the loss of capacity on the nation's highway facilities due to temporary phenomena as well as estimates of the impacts of such losses. The estimates produced by this study roughly indicate the magnitude of problems that are likely be addressed by the Congress during the next re-authorization of the Surface Transportation Programs. The scope of the study includes all urban and rural freeways and principal arterials in the nation's highway system for 1999. Specifically, this study attempts to quantify the extent of temporary capacity losses due to crashes, breakdowns, work zones, weather, and sub-optimal signal timing. These events can cause impacts such as capacity reduction, delays, trip rescheduling, rerouting, reduced mobility, and reduced reliability. This study focuses on the reduction of capacity and resulting delays caused by the temporary

  15. Anti-backlash gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2009-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission. One preferred embodiment discloses and describes an anti-backlash feature to counter ''dead zones'' in the gear bearing movement.

  16. Experimental Study on Post Grouting Bearing Capacity of Large Diameter Bored Piles

    Directory of Open Access Journals (Sweden)

    Wang Duanduan

    2015-01-01

    Full Text Available Post grouting can improve the inherent defects such as the formation of the mud cake at pile side and the sediment at pile end in the process of bored pile construction. Thus post grouting has been widely used in Engineering. The purpose of this paper is to research the influences of post grouting to pile bearing capacity more systematically and intuitively. Combined with the static load test of four test piles in Weihe River Bridge test area of new airport highway in Xi’an, the bearing capacity and settlement of routine piles and post grouting piles are comparatively analyzed. The test results show that under the same geological condition, post grouting can improve the properties of pile tip and pile shaft soil of bored piles significantly, enhance the ultimate resistance, improve the ultimate bearing capacity and reduce the pile tip settlement. Then post grouting can aim to optimize pile foundation.

  17. Damping Bearings In High-Speed Turbomachines

    Science.gov (United States)

    Von Pragenau, George L.

    1994-01-01

    Paper presents comparison of damping bearings with traditional ball, roller, and hydrostatic bearings in high-speed cryogenic turbopumps. Concept of damping bearings described in "Damping Seals and Bearings for a Turbomachine" (MFS-28345).

  18. Aerospace applications of magnetic bearings

    Science.gov (United States)

    Downer, James; Goldie, James; Gondhalekar, Vijay; Hockney, Richard

    1994-01-01

    Magnetic bearings have traditionally been considered for use in aerospace applications only where performance advantages have been the primary, if not only, consideration. Conventional wisdom has been that magnetic bearings have certain performance advantages which must be traded off against increased weight, volume, electric power consumption, and system complexity. These perceptions have hampered the use of magnetic bearings in many aerospace applications because weight, volume, and power are almost always primary considerations. This paper will review progress on several active aerospace magnetic bearings programs at SatCon Technology Corporation. The magnetic bearing programs at SatCon cover a broad spectrum of applications including: a magnetically-suspended spacecraft integrated power and attitude control system (IPACS), a magnetically-suspended momentum wheel, magnetic bearings for the gas generator rotor of a turboshaft engine, a vibration-attenuating magnetic bearing system for an airborne telescope, and magnetic bearings for the compressor of a space-rated heat pump system. The emphasis of these programs is to develop magnetic bearing technologies to the point where magnetic bearings can be truly useful, reliable, and well tested components for the aerospace community.

  19. Nanoprecipitation in bearing steels

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, A.T.W. [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom); Rivera-Diaz-del-Castillo, P.E.J., E-mail: pejr2@cam.ac.uk [SKF University Technology Centre, Department of Materials Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

    2011-11-15

    {theta}-phase is the main hardening species in bearing steels and appears in both martensitically and bainitically hardened microstructures. This work presents a survey of the microstrucural features accompanying nanoprecipitation in bearing steels. Nanoprecipitate structures formed in 1C-1.5Cr wt.% with additions of Cr, Mn, Mo, Si and Ni are studied. The work is combined with thermodynamic calculations and neural networks to predict the expected matrix composition, and whether this will transform martensitically or bainitically. Martensite tetragonality, composition and the amount of retained austenite are related to hardness and the type of nanoprecipitate structures in martensitic grades. The {theta}-phase volume fraction, the duration of the bainite to austenite transformation and the amount of retained austenite are related to hardness and a detailed quantitative description of the precipitate nanostructures. Such description includes compositional studies using energy-dispersive spectroscopy, which shows that nanoprecipitate formation takes place under paraequilibrium. Special attention is devoted to a novel two-step bainite tempering process which shows maximum hardness; we prove that this is the most effective process for incorporating solute into the precipitates, which are finer than those resulting from one-step banitic transformation processes.

  20. 78 FR 26064 - Endangered and Threatened Wildlife and Plants; Draft Conservation Strategy for the Northern...

    Science.gov (United States)

    2013-05-03

    ... for the Northern Continental Divide Ecosystem Grizzly Bear AGENCY: Fish and Wildlife Service, Interior... Divide Ecosystem grizzly bear (Ursus arctos horriblis) population for public review and input. The strategy will be the post- delisting management plan for the NCDE grizzly bears and their habitat....

  1. 23 CFR Appendix C to Subpart A of... - Federal-Aid Highway Contractors Annual EEO Report (Form PR-1391)

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Federal-Aid Highway Contractors Annual EEO Report (Form PR-1391) C Appendix C to Subpart A of Part 230 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF... Construction Contracts (Including Supportive Services) Pt. 230, Subpt. A, App. C Appendix C to Subpart A...

  2. Computational design of rolling bearings

    CERN Document Server

    Nguyen-Schäfer, Hung

    2016-01-01

    This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

  3. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    SHI Chun-xiang; GUO Zhong-yin

    2008-01-01

    A linear full 3D finite element method (FEM) was performed in order to present the key design parameters of highway tunnel asphalt pavement under double-wheel load on rectangular loaded area considering horizontal contact stress induced by the acceleration/deceleration of vehicles. The key design parameters are the maximum horizontal tensile stresses at the surface of the asphalt layer, the maximum horizontal tensile stresses at the bottom of the asphalt layer and the maximum vertical shear stresses at the surface of the as- phalt layer were calculated. The influencing factors such as double-wheel weight; asphalt layer thickness; base course stiffness modulus and thickness; and the contact conditions among the structure layers on these key design parameters were also examined separately to propose construction procedures of highway tunnel asphalt pavement.

  4. Fracture Mechanics Prediction of Fatigue Life of Aluminum Highway Bridges

    DEFF Research Database (Denmark)

    Rom, Søren; Agerskov, Henning

    2015-01-01

    Fracture mechanics prediction of the fatigue life of aluminum highway bridges under random loading is studied. The fatigue life of welded joints has been determined from fracture mechanics analyses and the results obtained have been compared with results from experimental investigations. The fati......Fracture mechanics prediction of the fatigue life of aluminum highway bridges under random loading is studied. The fatigue life of welded joints has been determined from fracture mechanics analyses and the results obtained have been compared with results from experimental investigations...... against fatigue in aluminum bridges, may give results which are unconservative. Furthermore, it was in both investigations found that the validity of the results obtained from Miner's rule will depend on the distribution of the load history in tension and compression....

  5. Monitoring of a Landslide Induced by New Highway Construction

    Science.gov (United States)

    Hlavacova, Ivana; Kolomaznik, Jan; Halounova, Lena

    2015-05-01

    During a highway construction, a nearby slope was discovered to be sliding down due to the geological character of the area. Our aim is to find the extent of the landslide and to find out whether the landslide was active even before the start of the highway construction. Persistent scatterers InSAR method has been applied using two tracks of Envisat ASAR data. The area of interest has a rural character. The time-series of ASAR data suffer from a couple of 1-year time gaps as well as long perpendicular baselines. Exclusion of the scenes from the processing was not feasible, because in that case there would be too few scenes for processing. On the contrary, we try to estimate the approximate accuracy empirically and separately for each date of acquisition.

  6. Risk assessment of wind turbines close to highways

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Sørensen, Jens Nørkær; Lemming, Jørgen Kjærgaard

    2012-01-01

    from Denmark and abroad and with the same basic technology as new large wind turbines. These data contain information on events where parts of the turbine is thrown / dropped at a distance from the turbine. Based on the data, the risk is estimated that persons in car are killed because of wind turbine......This paper describes an assessment of the minimum distance from wind turbines to highways based on risk assessments of the consequences due to total or partial failure of a wind turbine and due to ice throw in case of over-icing. Data has been collected from a large number of modern wind turbines...... parts 'thrown away' from a wind turbine in events with total or partial failure. The risk is expressed as a probability per kilometer. It is assumed that a row of wind turbines is placed along a highway with a typical total height of 120m (equivalent to wind turbines in the underlying data base...

  7. Measurements of air pollution from a Danish highway

    Energy Technology Data Exchange (ETDEWEB)

    Ellermann, T.; Solvang Jensen, S.; Ketzel, M.; Loefstroem, P. Massling, A.

    2009-07-15

    This report presents the results from a measurement campaign carried out at the Holbaek Highway during 2008. The objective of the campaign was to determine the emission factors for PM{sub 2.5} and PM{sub 10} due to highway traffic. The campaign included measurements of NO{sub x}, NO, NO{sub 2}, TEOM PM{sub 2.5}, TEOM PM{sub 10}, O{sub 3}, particle size distribution and local meteorology. The emission factors for PM{sub 2.5} and PM{sub 10} were determined to 45 and 155 mg/(vehicle km), respectively. This is comparable to the emission factors previously determined for H. C. Andersens Boulevard in Copenhagen and somewhat higher than found at Jagtvej, Copenhagen. (author)

  8. Research on combined coal mining technology under highway

    Science.gov (United States)

    Luo, Xiao; Zhang, Wenjun

    2017-05-01

    Based on the 3107 working face of a mine in Shanxi province, using the theoretical calculation and field measurement methods, explored a coal mining technology by combining use of the caving method and the roadway filling method, to solve the coal mining problems under the highway, under the premise that not change the mining layout of the coal mine. The results show that it is feasible to solve the problem of coal mining under the highway by using the combined mining technology. The surface subsidence can be controlled at the range of 282 to 312mm and 278 85mm, in parallel to and vertical to the working face direction, respectively, by using this technology; and the maximum slope of the surface deformation was controlled at 1.52mm/m, and all of the deformation variables are controlled under the requirement of the regulation

  9. Highway 3D model from image and lidar data

    Science.gov (United States)

    Chen, Jinfeng; Chu, Henry; Sun, Xiaoduan

    2014-05-01

    We present a new method of highway 3-D model construction developed based on feature extraction in highway images and LIDAR data. We describe the processing road coordinate data that connect the image frames to the coordinates of the elevation data. Image processing methods are used to extract sky, road, and ground regions as well as significant objects (such as signs and building fronts) in the roadside for the 3D model. LIDAR data are interpolated and processed to extract the road lanes as well as other features such as trees, ditches, and elevated objects to form the 3D model. 3D geometry reasoning is used to match the image features to the 3D model. Results from successive frames are integrated to improve the final model.

  10. Hydraulic performance of grass swales for managing highway runoff.

    Science.gov (United States)

    Davis, Allen P; Stagge, James H; Jamil, Eliea; Kim, Hunho

    2012-12-15

    The hydraulic performance of grass swales as a highway stormwater control measure was evaluated in a field-scale study adjacent to a Maryland highway. Two common swale design alternatives, pretreatment grass filter strips and vegetated check dams, were compared during 52 storm events over 4.5 years. Swale performance is described via three regimes, dependent on the relative size of the rainfall event. Overall, half of the events were small enough that the entire flow was stored, infiltrated, and evapotranspirated by the swales, resulting in no net swale discharge. Swales significantly reduced total volume and flow magnitudes generally during events with rainfall less than 3 cm. While the majority of improvement can be attributed to the swales, inclusion of check dams increases swale effectiveness. Pretreatment grass filter strips produced mixed effects. The swales demonstrated essentially no volumetric reduction during large storm events, functioning instead as conveyance, and smoothing fluctuations in flow.

  11. Robust Vehicle and Traffic Information Extraction for Highway Surveillance

    Directory of Open Access Journals (Sweden)

    C.-C. Jay Kuo

    2005-08-01

    Full Text Available A robust vision-based traffic monitoring system for vehicle and traffic information extraction is developed in this research. It is challenging to maintain detection robustness at all time for a highway surveillance system. There are three major problems in detecting and tracking a vehicle: (1 the moving cast shadow effect, (2 the occlusion effect, and (3 nighttime detection. For moving cast shadow elimination, a 2D joint vehicle-shadow model is employed. For occlusion detection, a multiple-camera system is used to detect occlusion so as to extract the exact location of each vehicle. For vehicle nighttime detection, a rear-view monitoring technique is proposed to maintain tracking and detection accuracy. Furthermore, we propose a method to improve the accuracy of background extraction, which usually serves as the first step in any vehicle detection processing. Experimental results are given to demonstrate that the proposed techniques are effective and efficient for vision-based highway surveillance.

  12. Prototype testing of magnetic bearings

    Science.gov (United States)

    Plant, David P.; Jayaraman, Chaitanya P.; Frommer, David A.; Kirk, James A.; Anand, Davinder K.

    1987-01-01

    The testing and evaluation of the performance of a magnetic bearing assembly for flywheel energy storage applications are discussed. The experimental set up for determining the passive radial stiffness, active radial stiffness, and curent force sensitivity of the coils follows the method developed by Frommer (1986). Magnetic bearings design should preclude saturation and current limiting in the desired operating range, so that the system will be linear. A larger linear range will lead to a more stable magnetic bearing.

  13. Grease lubrication in rolling bearings

    CERN Document Server

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  14. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

    A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt (PA) and flame-retarded porous asphalt (FRPA) were studied comparing with cement concrete pavement, dense-graded HMA and S MA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.

  15. The Design of Logistics Information Matching Platform for Highway Transportation

    Science.gov (United States)

    Chen, Daqiang; Zhu, Xiaoxiao; Tong, Bing; Shen, Xiahong; Feng, Tao

    The development status of logistics in the financial crisis requires the shippers and carriers' overall goal focus on cost reduction. This paper firstly analyzes the problem of information mismatch between shipper and carrier in nowadays, and describes the shippers and carriers' demand for information platform. Then based on requirement investigation and questionnaire statistics, the specific demands for logistics information matching platform are analyzed. Finally, logistics information matching platform system for highway transportation is designed.

  16. SAFETY-BASED CAPACITY ANALYSIS FOR CHINESE HIGHWAYS

    Directory of Open Access Journals (Sweden)

    Ping YI, Ph.D.

    2004-01-01

    Full Text Available Many years of research have led to the development of theories and methodologies in roadway capacity analysis in the developed countries. However, those resources coexist with roadway design and traffic control practices in the local country, and cannot be simply transferred to China for applications. For example, the Highway Capacity Manual in the United State describes roadway capacity under ideal conditions and estimates practical capacities under prevailing conditions in the field. This capacity and the conditions for change are expected to be different on Chinese roadways as the local roadway design (lane width, curves and grades, vehicle size, and traffic mix are different. This research looks into an approach to the capacity issue different from the Highway Capacity Manual. According to the car-following principle, this paper first describes the safety criteria that affect traffic operations. Several speed schemes are subsequently discussed as they are affected by the maximum speed achievable under the local conditions. The study has shown that the effect of geometric and traffic conditions can be effectually reflected in the maximum speed adopted by the drivers. For most Chinese highways without a posted speed limit, the choice of speed by the drivers from the safety prospective is believed to have incorporated considerations of the practical driving conditions. Based on this, a condition for capacity calculation is obtained by comparing the desired vs. safety-based distance headways. The formulations of the model are mathematically sound and physically meaningful, and preliminary testing of the model is encouraging. Future research includes field data acquisition for calibration and adjustment, and model testing on Chinese highways.

  17. Checklist for transition to new highway fuel(s).

    Energy Technology Data Exchange (ETDEWEB)

    Risch, C.; Santini, D.J. (Energy Systems)

    2011-12-15

    Transportation is vital to the U.S. economy and society. As such, U.S. Presidents have repeatedly stated that the nation needs to reduce dependence on petroleum, especially for the highway transportation sector. Throughout history, highway transportation fuel transitions have been completed successfully both in United States and abroad. Other attempts have failed, as described in Appendix A: Historical Highway Fuel Transitions. Planning for a transition is critical because the changes can affect our nation's ability to compete in the world market. A transition will take many years to complete. While it is tempting to make quick decisions about the new fuel(s) of choice, it is preferable and necessary to analyze all the pertinent criteria to ensure that correct decisions are made. Doing so will reduce the number of changes in highway fuel(s). Obviously, changes may become necessary because of occurrences such as significant technology breakthroughs or major world events. With any and all of the possible transitions to new fuel(s), the total replacement of gasoline and diesel fuels is not expected. These conventional fuels are envisioned to coexist with the new fuel(s) for decades, while the revised fuel and vehicle infrastructures are implemented. The transition process must analyze the needs of the primary 'players,' which consist of the customers, the government, the fuel industry, and the automotive industry. To maximize the probability of future successes, the prime considerations of these groups must be addressed. Section 2 presents a succinct outline of the Checklist. Section 3 provides a brief discussion about the groupings on the Checklist.

  18. Cyanines Bearing Quaternary Azaaromatic Moieties

    OpenAIRE

    Sbliwa, Wanda; Matusiak, Grazyna; Bachowska, Barbara

    2006-01-01

    Selected cyanines bearing quaternary azaaromatic moieties are presented, showing their monomers, dimers and polymers, as well as their possible applications. Cyanines having NLO properties are also briefly described.

  19. Hydrostatic and hybrid bearing design

    CERN Document Server

    Rowe, W B

    1983-01-01

    Hydrostatic and Hybrid Bearing Design is a 15-chapter book that focuses on the bearing design and testing. This book first describes the application of hydrostatic bearings, as well as the device pressure, flow, force, power, and temperature. Subsequent chapters discuss the load and flow rate of thrust pads; circuit design, flow control, load, and stiffness; and the basis of the design procedures and selection of tolerances. The specific types of bearings, their design, dynamics, and experimental methods and testing are also shown. This book will be very valuable to students of engineering des

  20. National Highway Alignment from Namakkal to Erode Using GIS

    Directory of Open Access Journals (Sweden)

    T. Subramani

    2014-08-01

    Full Text Available The vision of the Highway Alignment is to increase the capacity, connectivity, efficiency and safety of the Highways System so as to enable balanced socioeconomic development of all sections of the people and all regions from NAMAKKAL to ERODE via and to reduce the traffic and travelling of the state. It is to establish shortest path for road network time in the roads which provide a better and comfortable base for updating the traffic and other related information in road administration. It is to identify the short route for the vehicles traveling from NAMAKKAL to ERODE and to reduce the time travel for the vehicles with possible paths or routes or places for laying eco-friendly highway. To optimize the route for the vehicles traveling from NAMAKKAL to ERODE using GIS with Network analysis tools. From this we can find the suitable route for peoples to carry out without any traffic disturbances and protecting the environment. It also took advantages of GIS capabilities that offer the ability to overlay maps, merge them, and perform spatial analysis on various layers of information in either two or three dimensions:

  1. Pollutant Removal from Highway Runoff Using Retention/Detention Units

    Directory of Open Access Journals (Sweden)

    Ashraf El-Shahat Elsayed

    2001-01-01

    Full Text Available Highway runoff contains total suspended solids, hydrocarbons, oil and greases, chloride, and other contaminants that are transported in solution and particulate forms to adjacent floodplains, roadside swales, and retention/detention ponds. Oil and grit chambers represent a type of retention/detention unit used for removing heavy particulates and adsorbed hydrocarbon particulates. Storage/sediment units also represent a type of retention/detention unit used for controlling peak flow and removing suspended solids. The aim of this study is to evaluate the effect of traffic volume and site characteristics on highway runoff quality. The study also aims to evaluate the performance of retention/detention units that collect runoff from the Prague-Brno and Prague-Plzeň highways, Czech Republic. The results of this study indicate no definitive relationship between average daily traffic and concentration of runoff constituents, though the site characteristics have a strong relation to some constituents. The results also show that retention/detention units are effective in treating organic compounds.

  2. The Application Study in Solar Energy Technology for Highway Service Area: A Case Study of West Lushan Highway Low-Carbon Service Area in China

    Directory of Open Access Journals (Sweden)

    Xiaochun Qin

    2015-01-01

    Full Text Available A lot of research works have been made concerning highway service area or solar technology and acquired great achievements. However, unfortunately, few works have been made combining the two topics together of highway service areas and solar energy saving to make a systemic research on solar technology application for highway service area. In this paper, taking West Lushan highway low-carbon service area in Jiangxi Province of China as the case study, the advantages, technical principles, and application methods of solar energy technology for highway service area including solar photoelectric technology and solar water heating technology were discussed based on the analysis of characteristics of highway low-carbon service area; the system types, operation mode, and installing tilt angle of the two kinds of solar systems suitable for highway service areas were confirmed. It was proved that the reduction of the cost by electricity savings of solar system was huge. Taking the investment of the solar systems into account, the payback period of solar photoelectric systems and solar water heating systems was calculated. The economic effect of the solar systems in West Lushan highway service area during the effective operation periods was also calculated and proved very considerable.

  3. The development of an ecological approach to manage the pollution risk from highway runoff.

    Science.gov (United States)

    Crabtree, B; Dempsey, P; Johnson, I; Whitehead, M

    2009-01-01

    In the UK, the Highways Agency is responsible for operating, maintaining and improving the strategic road network in England. One focus of the Highways Agency's ongoing research into the nature and impact of highway runoff is aimed at ensuring that the Highways Agency will meet the requirements of the EU Water Framework Directive. A research programme, undertaken in partnership with the Environment Agency, is in progress to develop a better understanding of pollutants in highway runoff and their ecological impact. The paper presents the outcome of a study to: (1) monitor pollutants in highway runoff under different climate and traffic conditions; (2) develop standards to assess potential ecological risks from soluble pollutants in highway runoff; and (3) develop a model to predict pollutant concentrations in highway runoff. The model has been embedded in a design tool incorporating risk assessment procedures and receiving water standards for soluble and insoluble pollutants--the latter has been developed elsewhere in another project within the research programme. The design tool will be used to support improved guidance on where, and to what level, treatment of runoff is required for highway designers to manage the risk of ecological impact from highway runoff.

  4. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  5. Permanent-Magnet Meissner Bearing

    Science.gov (United States)

    Robertson, Glen A.

    1994-01-01

    Permanent-magnet meissner bearing features inherently stable, self-centering conical configuration. Bearing made stiffer or less stiff by selection of magnets, springs, and spring adjustments. Cylindrical permanent magnets with axial magnetization stacked coaxially on rotor with alternating polarity. Typically, rare-earth magnets used. Magnets machined and fitted together to form conical outer surface.

  6. High-Performance Ball Bearing

    Science.gov (United States)

    Bursey, Roger W., Jr.; Haluck, David A.; Olinger, John B.; Owen, Samuel S.; Poole, William E.

    1995-01-01

    High-performance bearing features strong, lightweight, self-lubricating cage with self-lubricating liners in ball apertures. Designed to operate at high speed (tens of thousands of revolutions per minute) in cryogenic environment like liquid-oxygen or liquid-hydrogen turbopump. Includes inner race, outer race, and cage keeping bearing balls equally spaced.

  7. Superconducting bearings for flywheel applications

    DEFF Research Database (Denmark)

    Abrahamsen, A.B.

    2001-01-01

    A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

  8. What about the Javan Bear?

    NARCIS (Netherlands)

    Jentink, F.A.

    1898-01-01

    The other day I read in a dutch popular periodical a paper dealing with the different species of Bears and their geographical distribution. To my great surprise the Malayan Bear was mentioned from Java: the locality Java being quite new to me I wrote to the author of that paper and asked him some in

  9. Grizzly Staus Report

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, Benjamin [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhang, Yongfeng [Idaho National Lab. (INL), Idaho Falls, ID (United States); Chakraborty, Pritam [Idaho National Lab. (INL), Idaho Falls, ID (United States); Backman, Marie [Idaho National Lab. (INL), Idaho Falls, ID (United States); Hoffman, William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Schwen, Daniel [Idaho National Lab. (INL), Idaho Falls, ID (United States); Biner, S. Bulent [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bai, Xianming [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-09-01

    This report summarizes work during FY 2014 to develop capabilities to predict embrittlement of reactor pressure vessel steel, and to assess the response of embrittled reactor pressure vessels to postulated accident conditions. This work has been conducted a three length scales. At the engineering scale, 3D fracture mechanics capabilities have been developed to calculate stress intensities and fracture toughnesses, to perform a deterministic assessment of whether a crack would propagate at the location of an existing flaw. This capability has been demonstrated on several types of flaws in a generic reactor pressure vessel model. Models have been developed at the scale of fracture specimens to develop a capability to determine how irradiation affects the fracture toughness of material. Verification work has been performed on a previously-developed model to determine the sensitivity of the model to specimen geometry and size effects. The effects of irradiation on the parameters of this model has been investigated. At lower length scales, work has continued in an ongoing to understand how irradiation and thermal aging affect the microstructure and mechanical properties of reactor pressure vessel steel. Previously-developed atomistic kinetic monte carlo models have been further developed and benchmarked against experimental data. Initial work has been performed to develop models of nucleation in a phase field model. Additional modeling work has also been performed to improve the fundamental understanding of the formation mechanisms and stability of matrix defects caused.

  10. Space Station alpha joint bearing

    Science.gov (United States)

    Everman, Michael R.; Jones, P. Alan; Spencer, Porter A.

    1987-01-01

    Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

  11. Floodflow characteristics of Filbin Creek at proposed interstate highway 526, North Charleston, South Carolina

    Science.gov (United States)

    Bohman, L.R.

    1984-01-01

    A study to determine the impact of two alternative construction plans for proposed interchange between the existing Interstate Highway 26 and Interstate Highway 526 in the Filbin Creek drainage basin near North Charleston, South Carolina was performed by the U.S. Geological Survey, in cooperation with the South Carolina Department of Highways and Public Transportation. A computerized reservoir routing technique was used to route synthetic flood hydrographs through the basin system. Simulation results indicate that the new roadway will cause little or no change in water-surface elevations downstream of Interstate Highway 26. Upstream of Interstate Highway 26, approximately 0.5 foot of backwater will be created by either alternative during a 100-year flood as a result of the Interstate Highway 526 embankments and structures. (USGS)

  12. Impacts of new highways and subsequent landscape urbanization on stream habitat and biota

    Science.gov (United States)

    Wheeler, A.P.; Angermeier, P.L.; Rosenberger, A.E.

    2005-01-01

    New highways are pervasive, pernicious threats to stream ecosystems because of their short- and long-term physical, chemical, and biological impacts. Unfortunately, standard environmental impact statements (EISs) and environmental assessments (EAs) focus narrowly on the initial direct impacts of construction and ignore other long-term indirect impacts. More thorough consideration of highway impacts, and, ultimately, better land use decisions may be facilitated by conceptualizing highway development in three stages: initial highway construction, highway presence, and eventual landscape urbanization. Highway construction is characterized by localized physical disturbances, which generally subside through time. In contrast, highway presence and landscape urbanization are characterized by physical and chemical impacts that are temporally persistent. Although the impacts of highway presence and landscape urbanization are of similar natures, the impacts are of a greater magnitude and more widespread in the urbanization phase. Our review reveals that the landscape urbanization stage is clearly the greatest threat to stream habitat and biota, as stream ecosystems are sensitive to even low levels (<10%) of watershed urban development. Although highway construction is ongoing, pervasive, and has severe biological consequences, we found few published investigations of its impacts on streams. Researchers know little about the occurrence, loading rates, and biotic responses to specific contaminants in highway runoff. Also needed is a detailed understanding of how highway crossings, especially culverts, affect fish populations via constraints on movement and how highway networks alter natural regimes (e.g., streamflow, temperature). Urbanization research topics that may yield especially useful results include a) the relative importance and biological effects of specific components of urban development - e.g., commercial or residential; b) the scenarios under which impacts are

  13. Response of benthic macroinvertebrate communities to highway construction in an Appalachian watershed

    Science.gov (United States)

    Hedrick, Lara B.; Welsh, S.A.; Anderson, James T.; Lin, L.-S.; Chen, Y.; Wei, X.

    2010-01-01

    Highway construction in mountainous areas can result in sedimentation of streams, negatively impacting stream habitat, water quality, and biotic communities. We assessed the impacts of construction of a segment of Corridor H, a four-lane highway, in the Lost River watershed, West Virginia, by monitoring benthic macroinvertebrate communities and water quality, before, during, and after highway construction and prior to highway use at upstream and downstream sites from 1997 through 2007. Data analysis of temporal impacts of highway construction followed a Before-After-Control-Impact (BACI) study design. Highway construction impacts included an increase in stream sedimentation during the construction phase. This was indicated by an increase in turbidity and total suspended solids. Benthic macroinvertebrate metrics indicated a community more tolerant during and after construction than in the period before construction. The percent of Chironomidae and the Hilsenhoff Biotic Index (HBI) increased, while percent of Ephemeroptera, Plecoptera, and Trichoptera (EPT) decreased. Our 10-year study addressed short-term impacts of highway construction and found that impacts were relatively minimal. A recovery of the number of EPT taxa collected after construction indicated that the benthic macroinvertebrate community may be recovering from impacts of highway construction. However, this study only addressed a period of 3 years before, 3 years during, and 4 years post construction. Inferences cannot be made concerning the long-term impacts of the highway, highway traffic, runoff, and other factors associated with highway use. Continual monitoring of the watershed is necessary to determine if the highway has a continual impact on stream habitat, water quality, and biotic integrity. ?? 2010 Springer Science+Business Media B.V.

  14. Get fit with the Grizzlies: a community-school-home initiative to fight childhood obesity led by a professional sports organization.

    Science.gov (United States)

    Irwin, Carol; Irwin, Richard; Richey, Phyllis; Miller, Maureen; Boddie, Justin; Dickerson, Teresa

    2012-01-01

    Professional sports organizations in the United States have notable celebrity status, and several teams have used this "star power" to collaborate with local schools toward the goal of affecting childhood obesity (e.g., NFL Play 60). Program effectiveness is unknown owing to the absence of comprehensive evaluations for any of these initiatives. In 2006, the Memphis Grizzlies, the city's National Basketball Association (NBA) franchise, launched "Get Fit with the Grizzlies," a 6-week, curricular addition focusing on nutrition and physical activity for the 4th and 5th grades in Memphis City Schools. The health-infused mini-unit was delivered by the physical education teachers during their classes. National and local sponsors whose business objectives matched the "Get Fit" objectives were solicited to fund the program. Here we highlight the program evaluation results from the first year of "Get Fit" and the Journal of School Health article. However, the "Get Fit" program has now taken place in Memphis area schools for 5 years. During the 2010-11 school-year, "Get Fit" evolved into a new program called "Healthy Home Court" with Kellogg's as the primary sponsor. "Healthy Home Court" included the original fitness part of the program and added a breakfast component at high schools where data indicated great need. Kellogg's sponsored special "carts" with healthy breakfast options (i.e., fruit, protein bars) for students to grab and eat. This program matched their existing program "Food Away from Home." Research supports the objectives of these programs and has shown that breakfast consumption can have a positive impact on academic achievement, behavior in school, and overall health status. Survey research employed over the first 4 years measured health knowledge acquisition and health behavior change using a matched pre/post test design (n=2210) in randomly chosen schools (n=18) from all elementary schools in the Memphis area. McNemar's test for significance (<05) was

  15. Hydrological modeling using high resolution dem to level control on highways

    Science.gov (United States)

    Akbulut, Zeynep; Cömert, Çetin

    2016-04-01

    Floods are natural disasters that must be managed, controlled and taken precautions before it happens considering the damage they inflicted to environment and human lives. As to highways, the main vein of urban life flow, must be taken into consideration as a different entity that affected by excessive rainfalls and floods. Due to inadequate drainage that allow rainfall to form water ponds on highways cause vehicles to lose control and that lead vehicles to have traffic accidents. To reduce the traffic accidents caused by ponding waters on highways we need to know area of inundation and water depths. In this context we used FLO-2D Basic Model (2009) to hydrological modeling of Black Sea Coastal Highway with meteorological and hydrological data using a Digital Elevation Model (DEM). In this study, ponding areas on highways determined by simulating the rainfall with a high resolution DEM that can represent the actual road surface correctly. With this information, General Directorate of Highways (GDH) in Turkey can adjust the cross-sectional and longitudinal slope or build better and bigger drainage structures where water accumulated to prevent ponding. With the results obtained from Hydrological Model, GDH can rapidly control highways conformity to regulations before highways come into service. Also these ponding areas acquired by reveals where to prioritize in flood risk managements. Key Words: Area of Inundation, Digital Elevation Model, FLO-2D, Hydrological Modeling, Highway, Rainfall-Runoff Simulation, Water Depth.

  16. Map of Federal Lands Highway American Recovery and Reinvestment Act Projects -

    Data.gov (United States)

    Department of Transportation — The map depicts Federal Lands Highway (FLH) American Recovery and Reinvestment Act (ARRA) projects, which are administered through the Federal Lands Divisions (FLD)....

  17. Highway three-dimensional modeling based on Vehicle-borne laser data

    Science.gov (United States)

    Weili, Sun; Ruofei, Zhong; Jiangxia, Wei; Fanyang, Zeng

    2014-03-01

    The of Vehicle-borne LiDAR (Light Detection And Ranging) scanning technology is an efficiently practical approach on the acquisition and application of 3D information and its geographic elements of highway(including road surface, rails, attached facilities, slopes, ditches, etc.). The acquired information is significant on many aspects such as road maintenance, reconstruction, survey, landscape design, visualized modelling and highway hazard supervision and prevention. The initial laser data cannot be directly used to construct highway 3D model, operations of pre-processing are necessary. This paper presented a set of procedure about pre-processing laser data and constructing TIN (Triangle Irregular Net) model of highway.

  18. Integrated Evaluation on Highway Engineering Geological Hazard in Mountainous Area of Enshi, Hubei

    Institute of Scientific and Technical Information of China (English)

    ZHAN Bin

    2006-01-01

    Aiming at the geological features of highway engineering in mountainous area of Enshi, Hubei Province, the principles to set up an integrated evaluation system for highway engineering geological hazard are formulated. Then, the integrated evaluation system for highway engineering geological hazard in mountainous area of Enshi is established. In the evaluation system, the first-level evaluation indices are geological development degree, geological conditions, and damaging power, whereas the second-level indices including key factors affecting main kinds of geological hazard. Meanwhile, the borders of indices are determined. At last, the method of Fuzzy Comprehensive Evaluation (FCE) is adopted to quantitatively evaluate the highway engineering geological hazard in mountainous area of Enshi.

  19. Magnetic Bearings at Draper Laboratory

    Science.gov (United States)

    Kondoleon, Anthony S.; Kelleher, William P.; Possel, Peter D.

    1996-01-01

    Magnetic bearings, unlike traditional mechanical bearings, consist of a series of components mated together to form a stabilized system. The correct design of the actuator and sensor will provide a cost effective device with low power requirements. The proper choice of a control system utilizes the variables necessary to control the system in an efficient manner. The specific application will determine the optimum design of the magnetic bearing system including the touch down bearing. Draper for the past 30 years has been a leader in all these fields. This paper summarizes the results carried out at Draper in the field of magnetic bearing development. A 3-D radial magnetic bearing is detailed in this paper. Data obtained from recently completed projects using this design are included. One project was a high radial load (1000 pound) application. The second was a high speed (35,000 rpm), low loss flywheel application. The development of a low loss axial magnetic bearing is also included in this paper.

  20. EFFECT OF BEARING MACROGEOMETRY ON BEARING PERFORMANCE IN ELASTOHYDRODYNAMIC LUBRICATION

    Directory of Open Access Journals (Sweden)

    Emin GÜLLÜ

    2000-01-01

    Full Text Available During manufacturing, ideal dimension and mutual positioning of machine elements proposed in project desing can be achieved only within certain range of tolerances. These tolerances, being classified in two groups, related to micro and macro geometry of machine elements, don't have to effect the functioning of these elements. So, as for all machine elements, investigation of the effects of macro and micro tolerances for journal bearings is important. In this study, we have investigated the effect of macro geometric irregularities of journal bearings on performance characteristics. In this regard, we have studied the change of bearing performance in respect to deviation from ideal circle for an elliptic shaft with small ovality rolling in circular journal bearing.

  1. Approximation Algorithms for the Highway Problem under the Coupon Model

    Science.gov (United States)

    Hamane, Ryoso; Itoh, Toshiya; Tomita, Kouhei

    When a store sells items to customers, the store wishes to decide the prices of items to maximize its profit. Intuitively, if the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. So it would be hard for the store to decide the prices of items. Assume that the store has a set V of n items and there is a set E of m customers who wish to buy the items, and also assume that each item i ∈ V has the production cost di and each customer ej ∈ E has the valuation vj on the bundle ej ⊆ V of items. When the store sells an item i ∈ V at the price ri, the profit for the item i is pi = ri - di. The goal of the store is to decide the price of each item to maximize its total profit. We refer to this maximization problem as the item pricing problem. In most of the previous works, the item pricing problem was considered under the assumption that pi ≥ 0 for each i ∈ V, however, Balcan, et al. [In Proc. of WINE, LNCS 4858, 2007] introduced the notion of “loss-leader, ” and showed that the seller can get more total profit in the case that pi customer is interested in an interval on the line of the items) and the cycle highway problem (in which each customer is interested in an interval on the cycle of the items), and show approximation algorithms for the line highway problem and the cycle highway problem in which the smallest valuation is s and the largest valuation is l (this is called an [s, l]-valuation setting) or all valuations are identical (this is called a single valuation setting).

  2. Sexually transmitted infections among male highway coach drivers in Myanmar.

    Science.gov (United States)

    Aung, Wah Wah; Thant, Myo; Wai, Khin Thet; Aye, Mya Mya; Ei, Phyu Win; Myint, Thuzar; Thidar, Moe

    2013-05-01

    A cross sectional descriptive study was conducted from February 2008 to December 2009 at the largest Highway Terminal, Yangon, Myanmar to determine the prevalence of curable STIs (syphilis, gonorrhea, chlamydial infections, and trichomoniasis), to find out the associated factors for STIs, and to determine the antibiotic susceptibility pattern of gonococcal infection among highway drivers. Urine and blood specimens were collected from 601 male highway coach drivers after an interview about their behavior. Standard laboratory tests were carried out to detect STIs. Multivariate analysis was used to ascertain potential risk factors for STIs. The prevalence rates of syphilis, gonorrhea, chlamydial infections, and trichomoniasis were 4.8, 4.3, 5.7, and 9.8%, respectively. One hundred and two (17.0%) were infected with at least one of the tested four STIs, and 34 (5.7%) had STI co-infections (2STIs). Those who had multiple sexual contacts were likely to be infected with at least one STI, and those who had a history of inconsistent condom use within past two weeks and multiple sexual contacts were more likely to have STI co-infections (p < 0.05). Antimicrobial susceptibility of 21 Neisseria gonorrhoeae isolates showed that 85.7% were susceptible to azithromycin, 80.9% to spectinomycin, 66.7% to cefixime, 61.9% to ceftriaxone, and 38.1% to ciprofloxacin. The high prevalence of STIs in this study and the decreased susceptibility of Neisseria gonorrhoeae to cephalosporin and fluoroquinolone highlighted the role of periodic screening in early diagnosis and effective treatment of STIs among high-risk populations.

  3. Landscaping of highway medians and roadway safety at unsignalized intersections.

    Science.gov (United States)

    Chen, Hongyun; Fabregas, Aldo; Lin, Pei-Sung

    2016-05-01

    Well-planted and maintained landscaping can help reduce driving stress, provide better visual quality, and decrease over speeding, thus improving roadway safety. Florida Department of Transportation (FDOT) Standard Index (SI-546) is one of the more demanding standards in the U.S. for landscaping design criteria at highway medians near intersections. The purposes of this study were to (1) empirically evaluate the safety results of SI-546 at unsignalized intersections and (2) quantify the impacts of geometrics, traffic, and landscaping design features on total crashes and injury plus fatal crashes. The studied unsignalized intersections were divided into (1) those without median trees near intersections, (2) those with median trees near intersections that were compliant with SI-546, and (3) those with median trees near intersections that were non-compliant with SI-546. A total of 72 intersections were selected, for which five-year crash data from 2006-2010 were collected. The sites that were compliant with SI-546 showed the best safety performance in terms of the lowest crash counts and crash rates. Four crash predictive models-two for total crashes and two for injury crashes-were developed. The results indicated that improperly planted and maintained median trees near highway intersections can increase the total number of crashes and injury plus fatal crashes at a 90% confidence level; no significant difference could be found in crash rates between sites that were compliant with SI-546 and sites without trees. All other conditions remaining the same, an intersection with trees that was not compliant with SI-546 had 63% more crashes and almost doubled injury plus fatal crashes than those at intersections without trees. The study indicates that appropriate landscaping in highway medians near intersections can be an engineering technology that not only improves roadway environmental quality but also maintains intersection safety.

  4. Artificial ultra-fine aerosol tracers for highway transect studies

    Science.gov (United States)

    Cahill, Thomas A.; Barnes, David E.; Wuest, Leann; Gribble, David; Buscho, David; Miller, Roger S.; De la Croix, Camille

    2016-07-01

    The persistent evidence of health impacts of roadway aerosols requires extensive information for urban planning to avoid putting populations at risk, especially in-fill projects. The required information must cover both highway aerosol sources as well as transport into residential areas under a variety of roadway configurations, traffic conditions, downwind vegetation, and meteorology. Such studies are difficult and expensive to do, but were easier in the past when there was a robust fine aerosol tracer uniquely tied to traffic - lead. In this report we propose and test a modern alternative, highway safety flare aerosols. Roadway safety flares on vehicles in traffic can provide very fine and ultra-fine aerosols of unique composition that can be detected quantitatively far downwind of roadways due to a lack of upwind interferences. The collection method uses inexpensive portable aerosol collection hardware and x-ray analysis protocols. The time required for each transect is typically 1 h. Side by side tests showed precision at ± 4%. We have evaluated this technique both by aerosol removal in vegetation in a wind tunnel and by tracking aerosols downwind of freeways as a function of season, highway configuration and vegetation coverage. The results show that sound walls for at-grade freeways cause freeway pollution to extend much farther downwind than standard models predict. The elevated or fill section freeway on a berm projected essentially undiluted roadway aerosols at distances well beyond 325 m, deep into residential neighborhoods. Canopy vegetation with roughly 70% cover reduced very fine and ultra-fine aerosols by up to a factor of 2 at distances up to 200 m downwind.

  5. Application of PCC pile in soil improvement of highway

    Institute of Scientific and Technical Information of China (English)

    刘芝平; 刘汉龙; 谭慧明

    2008-01-01

    The construction process and load-bearing behaviors of Cast-in-place concrete thin-wall pipe piles are analyzed based on its application on Yantong Expressway Project. The low strain test, static load test and field excavation were also carried out, and the bearing capacity of the new pile can meet the requirements of design. With the increase of pile diameter, the bearing capacity is increased. The settlement of composite foundation is decreased, when the replacement ratio of pile is increased. The test results also show that the load carried by inner soils is neglectable. According to the tests and application, it can be concluded that the new type of pile is convenient to construction with high bearing capacity and reliable quality, which has great potential in practical engineering.

  6. Seismic vulnerability assessment of a steel-girder highway bridge equipped with different SMA wire-based smart elastomeric isolators

    Science.gov (United States)

    Hedayati Dezfuli, Farshad; Shahria Alam, M.

    2016-07-01

    Shape memory alloy wire-based rubber bearings (SMA-RBs) possess enhanced energy dissipation capacity and self-centering property compared to conventional RBs. The performance of different types of SMA-RBs with different wire configurations has been studied in detail. However, their reliability in isolating structures has not been thoroughly investigated. The objective of this study is to analytically explore the effect of SMA-RBs on the seismic fragility of a highway bridge. Steel-reinforced elastomeric isolators are equipped with SMA wires and used to isolate the bridge. Results revealed that SMA wires with a superelastic behavior and re-centering capability can increase the reliability of the bearing and the bridge structure. It was observed that at the collapse level of damage, the bridge isolated by SMA-HDRB has the lowest fragility. Findings also showed that equipping NRB with SMA wires decreases the possibility of damage in the bridge while, replacing HDRB with SMA-HDRB; or LRB with SMA-LRB increases the failure probability of the system at slight, moderate, and extensive limit states.

  7. Non-contacting "snubber bearing" for passive magnetic bearing systems

    Energy Technology Data Exchange (ETDEWEB)

    Post, Richard F

    2017-08-22

    A new non-contacting magnetic "snubber" bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

  8. Fatigue in Aluminum Highway Bridges under Random Loading

    DEFF Research Database (Denmark)

    Rom, Søren; Agerskov, Henning

    2014-01-01

    Fatigue damage accumulation in aluminum highway bridges under random loading is studied. The fatigue life of welded joints has been determined both experimentally and from a fracture mechanics analysis. In the experimental part of the investigation, fatigue test series on welded plate test...... is normally used in the design against fatigue in aluminum bridges, may give results which are unconservative. The validity of the results obtained from Miner’s rule will depend on the distribution of the load history in tension and compression....

  9. Ice Control with Brine Spread with Nozzles on Highways

    DEFF Research Database (Denmark)

    Bolet, Lars; Fonnesbech, Jens Kristian

    2010-01-01

    . The improvements gained by the county of Funen were mainly due to the use of technologies (brine spreading with nozzles) giving a more precise spread pattern than the traditional gritting of pre-wetted salt. The spread pattern for every spreader, tested in The County of Funen, has been meassured 3 hours after...... spreading on a highway with traffic. A total of 800 spots were measured for residual salt for every spreader. The measurements and the spread pattern for brine spreading with nozzles were so precisely, that we learned: “When there is moisture, water or ice on the road, we need to take into account...

  10. RESOURCE SAVING IN CONSTRUCTION INDUSTRY WITH HIGHWAY BRANCH AS EXAMPLE

    Directory of Open Access Journals (Sweden)

    A. V. Roudensky

    2011-01-01

    Full Text Available Consumption of energy is an objective (independent on cost fluctuations technical efficiency criterion of any construction or repair work. Highway/road (particularly bituminous pavement sector is an important construction industry part. Bituminous road pavement construction consists of such components as excavation and preparation of basic materials, manufacture of mixes, ready mix laying/compacting and transportation of all materials. Average energy consumption for every bituminous pavement construction component is assessed. Approach to resource and energy saving presented in the article may be used in construction industry to develop and implement innovativetechnical and organizational solutions both of general application and for individual projects.

  11. Risk assessment of wind turbines close to highways

    OpenAIRE

    Sørensen, John Dalsgaard; Sørensen, Jens Nørkær; Lemming, Jørgen Kjærgaard

    2012-01-01

    This paper describes an assessment of the minimum distance from wind turbines to highways based on risk assessments of the consequences due to total or partial failure of a wind turbine and due to ice throw in case of over-icing. Data has been collected from a large number of modern wind turbines from Denmark and abroad and with the same basic technology as new large wind turbines. These data contain information on events where parts of the turbine is thrown / dropped at a distance from the t...

  12. Hempcrete Noise Barrier Wall for Highway Noise Insulation : Research & Construction

    OpenAIRE

    KC, Prabesh

    2016-01-01

    The purpose of this thesis was to study the possibility of Hempcrete or hemp-lime composite noise barrier walls in the highways and to construct the walls for the acoustic test according to the European Union Standards EN ISO 717-1 and ISO 10140-2 for air-borne sound insulation. The thesis was commissioned by the company Hemprefine Oy, and all the standard tests were performed in the HAMK-Ruukki Sheet Metal Centre in Hämeenlinna and the VTT Technical Research Centre of Finland Ltd in Espoo. ...

  13. SUPER-THIN COATING MATERIAL FOR HIGH-GRADE HIGHWAY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The road surface of cement concrete in highway is easily cracked and even destroyed due to inhomogeneous subsiding of the road foundation. In this work, a super-thin-coating material is prepared in order to repair the destroyed thin road surface, in which polymers and steel-fibers are added into ordinary concrete to form a steel fiber reinforced polymer-cement-based composite. the composite was successfully used to repair road surface. Microstructure and mechanical properties of the composites are measured and analyzed.

  14. REDESIGN OF TRANSPORT SYSTEMS ON HIGHWAYS, STREETS AND AVENUES

    Directory of Open Access Journals (Sweden)

    Takashi OGUCHI

    2008-01-01

    The handling of transport demands, especially in urban areas with traffic congestion, is important because the prediction of demand is very difficult under such conditions the true demand possibly becoming a potentiality caused by traffic congestion. One of the solutions of this difficulty is also proposed. The junction treatments, including traffic signal control, dominate over the LOS of the road transport system network in urban streets and avenues. The process of design, control, and operation of junctions at critical intersections is proposed. A tentative evaluation method for highway LOS is also discussed.

  15. Multi-fractal analysis of highway traffic data

    Institute of Scientific and Technical Information of China (English)

    Shang Peng-Jian; Shen Jin-Sheng

    2007-01-01

    The purpose of the present study is to investigate the presence of multi-fractal behaviours in the traffic time series not only by statistical approaches but also by geometrical approaches. The pointwise H(o)lder exponent of a function is calculated by developing an algorithm for the numerical evaluation of H(o)lder exponent of time series. The traffic time series observed on the Beijing Yuquanying highway are analysed. The results from all these methods indicate that the traffic data exhibit the multi-fractal behaviour.

  16. Macroscopic modeling for traffic flow on three-lane highways

    Science.gov (United States)

    Chen, Jianzhong; Fang, Yuan

    2015-04-01

    In this paper, a macroscopic traffic flow model for three-lane highways is proposed. The model is an extension of the speed gradient model by taking into account the lane changing. The new source and sink terms of lane change rate are added into the continuity equations and the speed dynamic equations to describe the lane-changing behavior. The result of the steady state analysis shows that our model can describe the lane usage inversion phenomenon. The numerical results demonstrate that the present model effectively reproduces several traffic phenomena observed in real traffic such as shock and rarefaction waves, stop-and-go waves and local clusters.

  17. Highway of dreams a critical view along the information superhighway

    CERN Document Server

    Noll, A Michael

    2013-01-01

    This important volume reviews the history of the telecommunication superhighway pointing out its beginnings in the interactive TV and broadband highway of the wired cities more than two decades ago. It explains the technological uncertainties of the superhighway and many of its futuristic services, and also gives an understandable review of the technological principles behind today's modern telecommunication networks and systems. Recognizing that technology is only one factor in shaping the future, the author, a well-recognized telecommunications expert, analyzes the financial, policy

  18. Assessment of highway slope failure using neural networks

    Institute of Scientific and Technical Information of China (English)

    Tsung-lin LEE; Hung-ming LIN; Yuh-pin LU

    2009-01-01

    An artificial intelligence technique of back-propagation neural networks is used to assess the slope failure. On-site slope failure data from the South Cross-Island Highway in southern Taiwan are used to test the performance of the neural network model. The numerical results demonstrate the effectiveness of artificial neural networks in the evaluation of slope failure potential based on five major factors, such as the slope gradient angle, the slope height, the cumulative precipitation, daily rainfall and strength of materials.

  19. The effects of calcium magnesium acetate (CMA) deicing material on the water quality of Bear Creek, Clackamas County, Oregon, 1999

    Science.gov (United States)

    Tanner, Dwight Q.; Wood, Tamara M.

    2000-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the Oregon Department of Transportation (ODOT), to evaluate the effects of the highway deicing material, calcium magnesium acetate (CMA), on the water quality of Bear Creek, in the Cascade Range of Oregon. ODOT began using CMA (an alternative deicer that has fewer adverse environmental effects than road salt) in the mid-1990s and began this study with the USGS to ensure that there were no unexpected effects on the water quality of Bear Creek. Streamflow, precipitation, dissolved oxygen, pH, specific conductance, and water temperature were measured continuously through the 1998?99 winter. There was no measurable effect of the application of CMA to Highway 26 on the biochemical oxygen demand (BOD), calcium concentration, or magnesium concentration of Bear Creek and its tributaries. BOD was small in all of the water samples, some of which were collected before CMA application, and some of which were collected after application. Five-day BOD values ranged from 0.1 milligrams per liter to 1.5 milligrams per liter, and 20-day BOD values ranged from 0.2 milligrams per liter to 2.0 milligrams per liter. Dissolved copper concentrations in a small tributary ditch on the north side of Highway 26 exceeded the U.S. Environmental Protection Agency aquatic life criteria on three occasions. These exceedances were probably not caused by the application of CMA because (1) one of the samples was a background sample (no recent CMA application), and (2) dissolved copper was not detected in Bear Creek water samples to which CMA was added during laboratory experiments.

  20. A Passive Magnetic Bearing Flywheel

    Science.gov (United States)

    Siebert, Mark; Ebihara, Ben; Jansen, Ralph; Fusaro, Robert L.; Morales, Wilfredo; Kascak, Albert; Kenny, Andrew

    2002-01-01

    A 100 percent passive magnetic bearing flywheel rig employing no active control components was designed, constructed, and tested. The suspension clothe rotor was provided by two sets of radial permanent magnetic bearings operating in the repulsive mode. The axial support was provided by jewel bearings on both ends of the rotor. The rig was successfully operated to speeds of 5500 rpm, which is 65 percent above the first critical speed of 3336 rpm. Operation was not continued beyond this point because of the excessive noise generated by the air impeller and because of inadequate containment in case of failure. Radial and axial stiffnesses of the permanent magnetic bearings were experimentally measured and then compared to finite element results. The natural damping of the rotor was measured and a damping coefficient was calculated.

  1. Gas bearing operates in vacuum

    Science.gov (United States)

    Perkins, G. S.

    1975-01-01

    Bearing has restrictions to reduce air leaks and is connected to external pumpout facility which removes exhausted air. Token amount of air which is lost to vacuum is easily removed by conventional vacuum pump.

  2. Mixed-mu superconducting bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Mulcahy, Thomas M. (Western Springs, IL)

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  3. Segmented Hybrid Gasostatic Bearing Optimization

    Directory of Open Access Journals (Sweden)

    Prodan Nikolay Vasilevich

    2014-07-01

    Full Text Available The purpose of research-development of methods of numerical optimization rotatable support pads gasostatic hybrid bearing. In the world‘s aerospace engineering the gas-dynamic bearings are currently most common. They are characterized by the supporting layer of different designs, which ensures the workability of the rotors during starts and stops. The main problem of this bearing type, apart from the construction complexity is the wear of this supporting layer. Gas-static bearing has no such defect, since there is no physical contact between solid surfaces. This study presents the results of the hybrid bearing’s calculation, combining both technologies. The slotted nozzle of non-conventional shape that mirrors the solution of Reynolds equation’s isoline is studied. The dependences of the main parameters on the speed of the shaft’s rotation are discussed. The aerodynamic resistance of pads for different regimes of operation is investigated.

  4. Bear study, Karluk Lake, 1956

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Based on observations, 117 bears were estimated to live in the Karluk Lake area. The estimate was lower than estimates from 1952, and 1954-1955. Annual loss to...

  5. Nonlinear Control of Magnetic Bearings

    Institute of Scientific and Technical Information of China (English)

    Khac Duc Do; Dang Hoe Nguyen; Thanh Binh Nguyen

    2010-01-01

    In this paper, recent results controling nonlinear systems with output tracking error constraints are applied to the design of new tracking controllers for magnetic bearings. The proposed controllers can force the rotor to track a bounded and sufficiently smooth refer-ence trajectory asymptotically and guarantee non-contactedness be-tween the rotor and the stator of the magnetic bearings. Simulation results are included to illustrate the effectiveness of the proposed con-trollers.

  6. Comparison of Ferry Boat and Highway Bridge Energy Use

    Directory of Open Access Journals (Sweden)

    Wayne D. Cottrell

    2011-01-01

    Full Text Available Passenger ferries serve a variety of transport needs in the U.S., such as providing vital links across bodies of water, and supplementing highway bridges. In some cases in which there is a ferry connection but no bridge, a bridge would be impractical; in other cases, a bridge might be feasible. The paper compares the energy consumption of ferries and motor vehicles on bridges, to determine which link is more fuel efficient. One finding is that limited data are available on ferry boat fuel consumption: despite there being 208 ferry boat operators in the U.S. as of 2008, only eight were providing energy use data to the National Transit Database. Examinations of three of the systems found that the passenger-MPG of the ferries ranged from 2.61 to 14.00 (1.11 to 5.95 km/L, while that of the motor vehicles on adjacent highway bridge connections ranged from 25.34 to 32.45 (10.77 to 13.79 km/L. Data from the eight systems are used to develop a ferry MPG model. The model is used to show that the Ryer Island and Charles Hall Ferries are less fuel efficient than hypothetical bridges in those locations. The fuel efficiencies and consumptions of the ferries would equal those of motor vehicles on the bridges, however, if smaller vessels were used, and if the frequency of service was reduced.

  7. Pollution by lead near the Turin--Milan highway

    Energy Technology Data Exchange (ETDEWEB)

    Sapetti, C.; Arduino, E.

    1973-10-01

    Soil samples taken at 5 to 50 m from the Turin-Milan highway at depths ranging from 0 to 30 cm on two different sites were analyzed for lead residues by atomic absorption spectrophotometry following extraction by means of ammoniacal EDTA at pH 9. Soil samples from the surface layer taken in one well-ventilated site contained 11.5 to 12.4 ppM lead, while subsoil samples had 5.7 to 9.8 ppM. Soil samples taken in the other site with poor ventilation contained 23.5 to 43.3 ppM lead in the surface layer, and 9.2 to 15.4 ppM in the subsoil. Decrease of the lead concentrations in the soil with increasing depth and distance from the highway was noted. Plant samples taken from the same sites contained 6.4 to 32.2 ppM lead. Lead was fixed predominantly to the exchange complex; partly to the clay fraction, and partly to the humic fraction.

  8. Landslides along Highways: GIS-based Inventory and Planning Issues

    Science.gov (United States)

    Jaeger, Ann-Kathrin; Klose, Martin; Damm, Bodo

    2015-04-01

    Highways rank as critical transportation infrastructures that are at risk of landslides in many areas worldwide (e.g., Hungr et al., 1999; Bhandary et al., 2013). Safe and affordable operations of traffic routes constitute the two main criteria for transportation planning in landslide-prone terrain. A right balancing of these often conflicting priorities requires profound knowledge of landslide locations across highway networks and the costs caused by landslides in the past (e.g., Saha et al., 2005). Much of the direct costs affecting transportation departments relate to capital investments for landslide repair or mitigation and operational expenditures in connection with maintenance works. A systematic collection and inventory of such data sets combined with an acquisition of hazard information on vulnerable road sections is still rarely the case in engineering practice. This is despite significant cost impacts and budgetary burdens, especially in peripheral mountain areas where financial resources are naturally limited (e.g., Klose et al., 2014). The present contribution introduces a regional inventory of landslides along highways in the Harz Mountains, NW Germany. As subset of a landslide database for the entire country, this focused GIS-based inventory has been compiled in close collaboration with the Lower Saxony Department of Transportation. The inventory includes data sets gathered by archive studies and relies on high-quality information sources such as maintenance protocols, geotechnical reports, and documents from tendering, controlling, and accounting. A mapping tool in ArcGIS format is used to specify and visualize road sections affected by landslides. This spatial information on hazard exposure is complemented by narrative risk profiles for landslide sites showing a long history of damage events. By summarizing the occurrence dates of landslides, the associated damages, and the types and costs of repair or prevention, such risk profiles are useful to

  9. 77 FR 70423 - Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC...

    Science.gov (United States)

    2012-11-26

    ... Energy Regulatory Commission Black Bear Hydro Partners, LLC and Black Bear Development Holdings, LLC and Black Bear SO, LLC; Notice of Application for Partial Transfer of Licenses, and Soliciting Comments and Motions To Intervene On October 25, 2012, Black Bear Hydro Partners, LLC, sole licensee (transferor)...

  10. 76 FR 36173 - Notice of Final Federal Agency Actions on Proposed Highway in California

    Science.gov (United States)

    2011-06-21

    ... Federal Highway Administration Notice of Final Federal Agency Actions on Proposed Highway in California... Review of Actions by the California Department of Transportation (Caltrans), pursuant to 23 U.S.C. 327... 99/ State Route 219 (Kiernan Avenue) interchange in the community of Salida in Stanislaus County,...

  11. Regional Risk Evaluation of Flood Disasters for the Trunk-Highway in Shaanxi, China

    Directory of Open Access Journals (Sweden)

    Hong-Liang Qi

    2015-10-01

    Full Text Available Due to the complicated environment there are various types of highway disasters in Shaanxi Province (China. The damages caused are severe, losses are heavy, and have rapidly increased over the years, especially those caused by flood disasters along the rivers in mountainous areas. Therefore, research on risk evaluations, which play important roles in the prevention and mitigation of highway disasters are very important. An evaluation model was established based on the superposition theory of regional influencing factors to highway flood disasters. Based on the formation mechanism and influencing factors of highway flood disasters, the main influencing factors were selected. These factors include rainstorms, terrain slopes, soil types, vegetation coverage and regional river density, which are based on evaluation indexes from climate conditions and underlying surface of the basin. A regional risk evaluation of highway flood disasters in Shaanxi was established using GIS. The risk index was divided into five levels using statistical methods, in accordance with the regional characteristics of highway flood disasters. Considering the difference in upfront investments, road grade, etc, between expressways and trunk-highways in China, a regional risk evaluation of trunk-highway flood disasters was completed. The evaluation results indicate that the risk evaluation is consistent with the actual situation.

  12. PLUS highway network analysis: Case of in-coming traffic burden in 2013

    Science.gov (United States)

    Asrah, Norhaidah Mohd; Djauhari, Maman Abdurachman; Mohamad, Ismail

    2017-05-01

    PLUS highway is the largest concessionary in Malaysia. The study on PLUS highway development, in order to overcome the demand for efficient road transportation, is crucial. If the highways have better interconnected network, it will help the economic activities such as trade to increase. If economic activities are increasing, the benefit will come to the people and state. In its turn, it will help the leaders to plan and conduct national development program. In this paper, network analysis approach will be used to study the in-coming traffic burden during the year of 2013. The highway network linking all the toll plazas is a dynamic network. The objective of this study is to learn and understand about highway network in terms of the in-coming traffic burden entering to each toll plazas along PLUS highway. For this purpose, the filtered network topology based on the forest of all possible minimum spanning trees is used. The in-coming traffic burden of a city is represented by the number of cars passing through the corresponding toll plaza. To interpret the filtered network, centrality measures such as degree centrality, betweenness centrality, closeness centrality, eigenvector centrality are used. An overall centrality will be proposed if those four measures are assumed to have the same role. Based on the results, some suggestions and recommendations for PLUS highway network development will be delivered to PLUS highway management.

  13. 76 FR 44649 - Notice of Final Federal Agency Actions on Proposed Highway in Texas

    Science.gov (United States)

    2011-07-26

    ... 1899 ; and Land and Water Conservation Fund . 8. Executive Orders: E.O. 11990 Protection of Wetlands; E... Federal Highway Administration Notice of Final Federal Agency Actions on Proposed Highway in Texas AGENCY... Texas. Those actions grant licenses, permits and approvals for the project. DATES: By this notice,...

  14. Road Tripping down the Digital Preservation Highway: Part IV--Classic Rides

    Science.gov (United States)

    Colati, Jessica Branco; Colati, Gregory C.

    2011-01-01

    "Road Tripping Down the Digital Preservation Highway" follows the continuing adventures of Peter Palmer, erstwhile librarian at Bellaluna University and manager of the library's and University's digital content, as he journeys down the Digital Preservation Highway. Palmer's problem this month was somewhat more philosophical. As manager of the…

  15. Road Tripping Down the Digital Preservation Highway: Part III. Rolls Royce, Ford, or Dune Buggy?

    Science.gov (United States)

    Colati, Jessica Branco; Colati, Gregory C.

    2011-01-01

    "Road Tripping Down the Digital Preservation Highway" follows the continuing adventures of Peter Palmer, erstwhile librarian at Bellaluna University and manager of the library's and University's digital content, as he journeys down the Digital Preservation Highway. In this article, Palmer is put in charge of a task force to determine…

  16. Random-parameters analysis of highway characteristics on crash frequency and injury severity

    Directory of Open Access Journals (Sweden)

    Bismark R.D.K. Agbelie

    2016-06-01

    Full Text Available Factors that affect highway-related crash frequency and injury severity vary across observations. Using a methodology that does not account nor correct for heterogeneity in observed and unobserved crash factors across highway segments may lead to biased and inconsistent estimated coefficients, thus resulting in erroneous inferences. The present paper demonstrates the use of random-parameters models to facilitate and enhance how crash factors affect crash frequency and injury severity along a highway segment. The results indicate that a unit increase in the presence of stop sign along a highway segment reduces crash frequency by 2.471 for 87.24% of the roadway segments. For the remaining 12.76% of the roadway segments, crash frequency is increased by the same margin. Using the random-parameters multinomial logit model, the result indicates that, for 90.89% of the observations, the presence of a stop sign on a highway segment increases the probability of the injury outcome. For 9.11% of the observations, the presence of a stop sign on a highway segment reduces the probability of the injury outcome, and the marginal effect value across observations is 0.0017. Vertical grades greater than 5% increase crash frequency for 58.46% of the highway segments, and decrease for 41.54% of the highway segments by 0.121 for one unit increase in vertical grades.

  17. 23 CFR Appendix A to Subpart C of... - State Highway Agency Equal Employment Opportunity Programs

    Science.gov (United States)

    2010-04-01

    ... promotions, i.e., advancement of minorities and women to key jobs, new career heights, etc. d. Training. The...). part i—contractor compliance I. Organization and structure. A. Statehighway agency EEO Coordinator... highway agency EEO Coordinator. (Provided organization charts of the State highway agency and of the...

  18. 78 FR 25524 - Notice of Final Federal Agency Actions on Proposed Highway in California

    Science.gov (United States)

    2013-05-01

    ... Populations; E.O. 11593 Protection and Enhancement of the Cultural Environment; E.O. 13007 Indian Sacred Sites... Federal Highway Administration Notice of Final Federal Agency Actions on Proposed Highway in California... Review of Actions by the California Department of Transportation (Caltrans), pursuant to 23 U.S.C....

  19. 75 FR 3522 - Notice of Final Federal Agency Actions on Proposed Highway in California

    Science.gov (United States)

    2010-01-21

    ... and Enhancement of the Cultural Environment; E.O. 13007 Indian Sacred Sites; E.O. 13287 Preserve... Federal Highway Administration Notice of Final Federal Agency Actions on Proposed Highway in California... Review of Actions by the California Department of Transportation (Caltrans), pursuant to 23 USC...

  20. 75 FR 36466 - Notice of Final Federal Agency Actions on Proposed Highway in California

    Science.gov (United States)

    2010-06-25

    ... Cultural Environment; E.O. 13007 Indian Sacred Sites; E.O. 13287 Preserve America; E.O. 13175 Consultation... Federal Highway Administration Notice of Final Federal Agency Actions on Proposed Highway in California... Review of Actions by the California Department of Transportation (Caltrans), pursuant to 23 U.S.C....