295 research outputs found
Prolonged Intensive Dominance Behavior Between Gray Wolves, Canis lupus
Dominance is one of the most pervasive and important behaviors among wolves in a pack, yet its significance in free-ranging packs has been little studied. Insights into a behavior can often be gained by examining unusual examples of it. In the High Arctic near Eureka, Nunavut, Canada, we videotaped and described an unusually prolonged and intensive behavioral bout between an adult male Gray Wolf (Canis lupus) and a male member of his pack, thought to be a maturing son. With tail raised, the adult approached a male pack mate about 50 m from us and pinned and straddled this packmate repeatedly over 6.5 minutes, longer than we had ever seen in over 50 years of studying wolves. We interpreted this behavior as an extreme example of an adult wolf harassing a maturing offspring, perhaps in prelude to the offspring's dispersal
Long Daily Movements of Wolves, \u3ci\u3eCanis lupus\u3c/i\u3e, During Pup Rearing
Wolves, Canis lupus, on Ellesmere Island traveled a daily round-trip distance of 40.2 km from their den to a landfill during July 2008, plus an undetermined distance hunting after leaving the landfill. Although long travels by Wolves are well known, this appears to be the first documentation of long daily movements by Wolves rearing pups
Long Daily Movements of Wolves, Canis lupus, During Pup Rearing
Wolves, Canis lupus, on Ellesmere Island traveled a daily round-trip distance of 40.2 km from their den to a landfill during July 2008, plus an undetermined distance hunting after leaving the landfill. Although long travels by Wolves are well known, this appears to be the first documentation of long daily movements by Wolves rearing pups
Potentially Active Faults in Dam Foundations
The Paper contains information on existing dams founded on active faults, a summary of pertinent lessons learned from study of historic fault breaks and fault mechanisms, recommended practice for evaluation of active faults, and opinions concerning design of dams on active faults. While a dam site with an active fault should be avoided if possible, if a reservoir is vitally needed and a better site is not available, it is reasonable practice to construct a conservatively designed embankment dam. Concrete dams on active faults, or near some major active faults, are not advisable. For evaluation of fault activity, geological studies usually must be carried a considerable distance from the dam site, a departure from recent past practice. Experience of the last few years with many fault studies indicates that thorough geological investigations with modern techniques will usually provide sufficient evidence to allow a judgement on the activity or inactivity of a fault
Concepts in Coalmine Ventilation and Development of the VamTurBurner© for Extraction of Thermal Energy from Underground Ventilation Air Methane
Climate change is emerging as a significant challenge in terms of the
response needed to mitigate or adapt to the predicted global changes. Severe
impacts due to rising sea-level, seasonal shifts, increased frequency and intensity of
extreme weather events such as storms, floods or droughts have become accepted
by the scientific community as a real and present threat to civilisation. The most
significant impacts are expected in the Arctic, the Asian mega-deltas, Small Island
Developing States (SIDS) and sub-Saharan Africa (IPCC 2007). There are two
approaches to global climate change either mitigation or adaptation.
This dissertation aims to provide the initial design concepts for a system to
mitigate methane, a significant Greenhouse Gas (GHG), emitted from coalmines by
ventilation air circulated through the underground workings. The VamTurBurner©, a
Ventilation Air Methane (VAM) gas turbine based methane burning system, is
proposed as a method of extracting the thermal energy from the VAM. A key aspect
of the problem responsible for the difficulty in extracting the energy from VAM is the
low concentration of methane in the high volume ventilation airflow. This approach
recasts the concepts of combustion dynamics of a premixed fuel flow to that
expected for VAM to ascertain the conditions conducive to combustion or oxidation
of the methane in the ventilation air. A numerical model using Large Eddy
Simulation (LES) to study the combustion dynamics revealed that the temperature of
the incoming ventilation air is a key variable related to the concentration of the VAM.
Computational Fluid Dynamics modeling was used to study the design features
needed to engineer a system capable of providing the required temperature of the
incoming ventilation air.
Applications for the available thermal energy are discussed in terms of the
potential to generate electricity with steam turbines, provide space heating, produce
hot water for many uses, and use the heat for industrial drying or as desired. The
efficiency of the energy system is enhanced when the output from the amount of
natural gas or electricity purchased is compared to the output enhanced by the
addition of methane, considered as free. The VamTurBurner© concept, as
described in this dissertation, appears to be a viable method of mitigating
atmospheric methane in the pursuit greenhouse gas reduction.College of Engineering, Mathematics and Physical Science
- shell gap reduction in neutron-rich systems and cross-shell excitations in O
Excited states in O were populated in the reaction
Be(C,) at Florida State University. Charged particles
were detected with a particle telescope consisting of 4 annularly segmented Si
surface barrier detectors and radiation was detected with the FSU
detector array. Five new states were observed below 6 MeV from the
- and -- coincidence data. Shell model
calculations suggest that most of the newly observed states are core-excited
1p-1h excitations across the shell gap. Comparisons between
experimental data and calculations for the neutron-rich O and F isotopes imply
a steady reduction of the - shell gap as neutrons are added
Population Viability of Barren-ground Grizzly Bears in Nunavut and the Northwest Territories
We modelled probabilities of population decline as a function of annual kill for a population of barren-ground grizzly bears (Ursus arctos) inhabiting Nunavut and the Northwest Territories, Canada. Our results suggest that the population is at risk of decline, especially if annual removal rates increase from the 42-year mean of 13.4 bears per year. Adding six bears to the mean annual kill results in a greater than 40% chance of a decrease by one-quarter in population size over the next 50 years, compared to a 10% chance with the current level of human-caused mortality. Additional mortalities may result from increased problem behaviour by bears at mine sites or hunt and exploration camps, given recent increases in human activity in the region, and may already be present as unreported mortality. We believe any increase in current harvest quotas would considerably lessen conservation prospects for the population.On a simulé les probabilités de baisse de la population en fonction du prélèvement annuel dans le cadre de la chasse pour une population de grizzlis de la toundra (Ursus arctos) habitant le Nunavut et les Territoires du Nord-Ouest, au Canada. Nos résultats suggèrent que la population risque de décliner, surtout si les taux de prélèvement augmentent par rapport à la moyenne établie sur 42 ans qui est de 13,4 ours par an. Le fait d'ajouter 6 ours au prélèvement de chasse annuel augmente à plus de 40 % le risque que la population décline d'un quart au cours des prochains 50 ans, par rapport à 10 % dans le cas du niveau actuel de mortalité provoquée par les humains. Vu l'augmentation récente de l'activité anthropique dans la région, d'autres individus pourraient être abattus à cause du nombre croissant de comportements problématiques des ours résidant à des sites miniers et à des campements d'exploration, et il est possible que ce phénomène existe déjà mais que les morts ne soient pas rapportées. Notre opinion est que toute augmentation des quotas actuels de prélèvement réduirait considérablement les perspectives de conservation pour la population
Geographic isolation reduces genetic diversity of a wide-ranging terrestrial vertebrate, Canis lupus
Genetic diversity is theorized to decrease in populations closer to a species’ range edge, where habitat may be suboptimal. Generalist species capable of long-range dispersal may maintain sufficient gene flow to counteract this, though the presence of significant barriers to dispersal (e.g., large water bodies, human-dominated landscapes) may still lead to, and exacerbate, the edge effect. We used microsatellite data for 2421 gray wolves (Canis lupus) from 24 subpopulations (groups) to model how allelic richness and expected heterozygosity varied with mainland–island position and two measures of range edge (latitude and distance from range center) across >7.3 million km2 of northern North America. We expected low genetic diversity both at high latitudes, due to harsh environmental conditions, and on islands, but no change in diversity with distance to the range center due to the species’ exceptional dispersal ability and favorable conditions in far eastern and western habitats. We found that allelic richness and expected heterozygosity of island groups were measurably less than that of mainland groups, and that these differences increased with the island’s distance to the species’ range center in the study area. Our results demonstrate how multiple axes of geographic isolation (distance from range center and island habitation) can act synergistically to erode the genetic diversity of wide-ranging terrestrial vertebrate populations despite the counteracting influence of long-range dispersal ability. These findings emphasize how geographic isolation is a potential threat to the genetic diversity and viability of terrestrial vertebrate populations even among species capable of long-range dispersal
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