4,518 research outputs found
Modeling the Effects of Human Activity on Katmai Brown Bears (Ursus arctos) through the Use of Survival Analysis
Brown bear-human interactions were observed in 1993, 1995, and 1997 at Kulik River in Katmai National Park and Preserve, Alaska. We analyzed these interactions using survival analysis, creating survival curves for the time that bears remained on the river in the presence, and absence, of human activity. Bear-only survival curves did not vary significantly between years (p = 0.067). Ninety-seven percent of bears left the river within 70 minutes of arrival in all years. Temporal patterns of bear activity were unaffected by the presence of humans as long as the bears did not share river zones with humans (p = 0.062 to p = 0.360). When people and bears did not share river zones, 38.6% (1993), 36.0% (1995), and 37.0% (1997) of bears remained on the river for at least 10 minutes after arrival. In contrast, when people and bears shared river zones, fewer bears remained on the river after the first 10 minutes, with 28.6% (1993), 25.0% (1995), and 32.6% (1997) observed in each year. We conclude that human activity displaced 26.0% (1993), 30.5% (1995), and 12.0% (1997) of the bears using the river, which otherwise would likely have remained longer. Over the three years of study, habituation to human activity may account for observed changes in bears' use of the river.En 1993, 1995 et 1997, des interactions ours brun-être humain ont fait l'objet d'observations à la rivière Kulik, dans la réserve de parc national Katmai, en Alaska. On a analysé ces interactions en ayant recours à l'analyse de survie, créant des courbes de survie pour la durée où les ours restaient à la rivière en présence et en l'absence d'activité humaine. Les courbes de survie pour l'ours seul ne variaient pas sensiblement d'une année à l'autre (p = 0,067). Dans tous les cas, 97% des ours quittaient la rivière dans les 70 minutes suivant leur arrivée. Les schémas de comportement temporel des ours n'étaient pas affectés par la présence d'êtres humains tant que les ours ne partageaient pas les mêmes zones de rivière que les humains (p = 0,062 à p = 0,360). Quand individus et ours ne partageaient pas les mêmes zones de rivière, 38,6% (1993), 36,0% (1995) et 37,0% (1997) des ours restaient à la rivière au moins 10 minutes après leur arrivée. En revanche, quand individus et ours partageaient les zones de rivière, moins d'ours restaient à la rivière au-delà des 10 premières minutes, 28,6% (1993), 25,0% (1995) et 32,6% (1997) ayant été observés chaque année. On conclut que l'activité humaine a délogé 26,0% (1993), 30,5% (1995) et 12,0% (1997) des ours utilisant la rivière, qui, autrement, seraient restés plus longtemps. Au cours des trois années de l'étude, il se pourrait que l'accoutumance à l'activité humaine explique les changements que l'on a observés dans l'utilisation de la rivière par les ours
Pure pallets: effectiveness and efficiency impacts on the defense transportation system
The military supply chain must explore initiatives to improve its ability to meet warfighter needs. One initiative, developed during operations in Afghanistan and Iraq is the pure pallet process—by consolidating material early in the supply chain into user-specific pallets, these pallets are able to transit the defense transportation system without being broken down en route, theoretically arriving to the warfighter in less time than prior break-bulk methods required. The pure pallet initiative’s effectiveness and efficiency was assessed by measuring customer requisition wait time, cargo throughput, and revenue performance. It was found that effectiveness increased, without corresponding losses in efficiency
Ultrafast carrier dynamics in thin-films of the topological insulator Bi2Se3
Transient reflectivity measurements of thin films, ranging from 6 to 40 nm in
thickness, of the topological insulator Bi2Se3 revealed a strong dependence of
the carrier relaxation time on the film thickness. For thicker films the
relaxation dynamics are similar to those of bulk Bi2Se3, where the contribution
of the bulk insulating phase dominates over that of the surface metallic phase.
The carrier relaxation time shortens with decreasing film thickness, reaching
values comparable to those of noble metals. This effect may result from the
hybridization of Dirac cone states at the opposite surfaces for the thinnest
films
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Aircraft observations and model simulations of concentration and particle size distribution in the Eyjafjallajökull volcanic ash cloud
The Eyjafjallajökull volcano in Iceland emitted a cloud of ash into the atmosphere during April and May 2010. Over the UK the ash cloud was observed by the FAAM BAe-146 Atmospheric Research Aircraft which was equipped with in-situ probes measuring the concentration of volcanic ash carried by particles of varying sizes. The UK Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME) has been used to simulate the evolution of the ash cloud emitted by the Eyjafjallajökull volcano during the period 4–18 May 2010. In the NAME simulations the processes controlling the evolution of the concentration and particle size distribution include sedimentation and deposition of particles, horizontal dispersion and vertical wind shear. For travel times between 24 and 72 h, a 1/t relationship describes the evolution of the concentration at the centre of the ash cloud and the particle size distribution remains fairly constant. Although NAME does not represent the effects of microphysical processes, it can capture the observed decrease in concentration with travel time in this period. This suggests that, for this eruption, microphysical processes play a small role in determining the evolution of the distal ash cloud. Quantitative comparison with observations shows that NAME can simulate the observed column-integrated mass if around 4% of the total emitted mass is assumed to be transported as far as the UK by small particles (< 30 μm diameter). NAME can also simulate the observed particle size distribution if a distal particle size distribution that contains a large fraction of < 10 μm diameter particles is used, consistent with the idea that phraetomagmatic volcanoes, such as Eyjafjallajökull, emit very fine particles
Supervisor Cultural Responsiveness and Unresponsiveness in Cross-Cultural Supervision
Thirteen supervisees’ of color and 13 European American supervisees’ experiences of culturally responsive and unresponsive cross-cultural supervision were studied using consensual qualitative research. In culturally responsive supervision, all supervisees felt supported for exploring cultural issues, which positively affected the supervisee, the supervision relationship, and client outcomes. In culturally unresponsive supervision, cultural issues were ignored, actively discounted, or dismissed by supervisors, which negatively affected the supervisee, the relationship, and/or client outcomes. European American supervisees’ and supervisees’ of color experiences diverged significantly, with supervisees of color experiencing unresponsiveness more frequently and with more negative effects than European American supervisees. Implications for research and supervision practice are discussed
Perceptions of Well-Being Among Rural Nebraskans
Nebraska’s economy has been relatively stable during the past year. However, some rural areas continue to be economically challenged. How do rural Nebraskans perceive their quality of life? Do their perceptions differ by community size, the region in which they live, or their occupation? This report details 2,482 responses to the 2006 Nebraska Rural Poll, the eleventh annual effort to understand rural Nebraskans’ perceptions. Respondents were asked a series of questions regarding their individual well-being. Trends for these questions are examined by comparing data from the ten previous polls to this year’s results. In addition, comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc. Based on these analyses, some key findings emerged: • More rural Nebraskans report being satisfied with their job opportunities this year as compared to previous years. After reaching a low of 34 percent in 2004, the proportion satisfied with their job opportunities increased to 42 percent this year (the highest proportion in all 11 years). (page 5) • Persons with the highest household incomes are more likely than persons with lower incomes to feel they are better off compared to five years ago, are better off compared to their parents when they were their age, and will be better off ten years from now. For example, 52 percent of respondents with household incomes of 20,000 believe they will be better off ten years from now. (page 6) • More rural Nebraskans believe people are powerless to control their own lives this year as compared to past years. The proportion that either strongly agree or agree with the statement that people are powerless to control their own lives each year has averaged about 34 percent. The proportion agreeing with the statement increased slightly, to 38 percent this year, which matches the highest proportion in the 11 years of the Poll (1997 and 1999 were the other two years). (page 4) • Persons with lower education levels are more likely than persons with more education to believe that people are powerless to control their own lives. Forty-six percent of persons with a high school diploma or less education agree that people are powerless to control their own lives. However, only 25 percent of persons with a four-year college degree share this opinion. (page 9) • Rural Nebraskans continue to be generally positive about their current situation. Except in 2003, each year the proportion of rural Nebraskans that say they are better off than they were five years ago has been greater than the proportion saying they are worse off than they were five years ago. Approximately 36 percent each year have reported that they were better off than they were five years ago. This year, 35 percent believe they are better off then they were five years ago and 21 percent think they are worse off. (page 2) • Similarly, rural Nebraskans continue to be generally positive about their future. The proportion that say they will be better off ten years from now has always been greater than the proportion saying they will be worse off ten years from now (although the two were virtually identical in 1996). The proportion stating they will be better off ten years from now has generally remained about 36 percent. This year, the proportion was 34 percent. Twenty-one percent believe they will be worse off ten years from now. (page 3) • Following trends in previous years, rural Nebraskans are most satisfied with their marriage, family, friends, religion/spirituality and the outdoors. They continue to be less satisfied with job opportunities, current income level and financial security during retirement. (page 5
Effects of transition metal substitutions on the incommensurability and spin fluctuations in BaFe2As2 by elastic and inelastic neutron scattering
The spin fluctuation spectra from nonsuperconducting Cu-substituted, and
superconducting Co-substituted, BaFe2As2 are compared quantitatively by
inelastic neutron scattering measurements and are found to be indis-
tinguishable. Whereas diffraction studies show the appearance of incommensurate
spin-density wave order in Co and Ni substituted samples, the magnetic phase
diagram for Cu substitution does not display incommensu- rate order,
demonstrating that simple electron counting based on rigid-band concepts is
invalid. These results, supported by theoretical calculations, suggest that
substitutional impurity effects in the Fe plane play a signifi- cant role in
controlling magnetism and the appearance of superconductivity, with Cu
distinguished by enhanced impurity scattering and split-band behavior.Comment: 5 pages, 5 figures, Major change in the manuscrip
Cerebral Abscess and \u3ci\u3eCephenemyia phobifer\u3c/i\u3e in a Mule Deer in Central Nebraska
A wild yearling male mule deer (Odocoileus hemionus) from south central Nebraska was submitted to the University of Nebraska North Platte Station Diagnostic Laboratory with the history of severe depression, slight incoordination, and visual impairment. Gross examination revealed a large abcess involving approximately 65-75% of the cebral hemispheres of the brain and approximately bots in the retropharyngeal pouches
Cerebral Abscess and \u3ci\u3eCephenemyia phobifer\u3c/i\u3e in a Mule Deer in Central Nebraska
A wild yearling male mule deer (Odocoileus hemionus) from south central Nebraska was submitted to the University of Nebraska North Platte Station Diagnostic Laboratory with the history of severe depression, slight incoordination, and visual impairment. Gross examination revealed a large abcess involving approximately 65-75% of the cebral hemispheres of the brain and approximately bots in the retropharyngeal pouches
Perceptions of Latin American Immigration Among Rural Nebraskans
In an earlier Nebraska Rural Poll report (August 2006), rural Nebraskans were asked their opinions of newcomers in general to their community. Some parts of rural Nebraska have seen significant growth of a specific group of newcomers, Latin American immigrants. How do rural Nebraskans view recent immigrants from Latin America? How do they view various immigration policies? Do their views differ by community size, the region in which they live, or their education level? This report details 2,482 responses to the 2006 Nebraska Rural Poll, the eleventh annual effort to understand rural Nebraskans’ perceptions of current issues and conditions. Respondents were asked a series of questions regarding immigrants from Latin America and immigration policies. Comparisons are made among different respondent subgroups, that is, comparisons by age, occupation, region, etc
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