Using Visual Observations to Compare the Behavior of Previously Immobilized and Non-Immobilized Wild Polar Bears

During 17 field seasons between 1973 and 1999, we conducted a long-term study of the behavior of undisturbed wild polar bears in Radstock Bay, southwest Devon Island, Nunavut. In a subset of 11 seasons (6 spring and 5 summer) between 1975 and 1997, we used three different drug combinations to chemically immobilize a small number of adult and subadult polar bears on an opportunistic basis and applied a temporary dye mark so that individual bears could be visually reidentified. We then used multinomial logistic regression to compare the behavior of 35 previously immobilized bears of five different demographic classes (sex, age, and reproductive status) to the behavior of non-immobilized bears of the same demographic classes in the same years and seasons. During the first two days after immobilization, bears slept significantly more and spent less time hunting than did bears that had not been immobilized. However, previously immobilized bears returned to the same behavioral patterns and proportion of total time spent hunting as non-immobilized bears within two days and no further negative behavioral effects were detected in the following 21 d. We visually confirmed successful hunting by three adult bears within 0.4 to 2.1 d of being immobilized, all of which went on to make additional kills within the following 24 h. The return to normal behavior patterns, including the ability to hunt successfully, within 48 h of immobilization appears consistent with the hypothesis that polar bears do not experience longer-term behavioral effects following brief chemical immobilization for conservation and management purposes. Durant 17 saisons de recherche, entre 1973 et 1999, nous avons effectué l’étude à long terme du comportement d’ours polaires sauvages non perturbés à la baie Radstock, dans le sud-ouest de l’île Devon, au Nunavut. Dans un sous-ensemble de 11 saisons (six printemps et cinq étés) échelonnées de 1975 à 1997, nous avons utilisé trois combinaisons de drogues différentes pour immobiliser chimiquement un petit nombre d’ours polaires adultes et d’ours polaires immatures de manière opportuniste, puis nous avons appliqué une marque de colorant temporaire sur les ours afin de pouvoir les réidentifier individuellement. Ensuite, nous avons recouru à la régression logistique multinomiale pour comparer le comportement de 35 ours précédemment immobilisés faisant partie de cinq catégories démographiques différentes (sexe, âge et état reproducteur) au comportement d’ours non immobilisés faisant partie des mêmes catégories démographiques pour les mêmes années et les mêmes saisons. Au cours des deux premières journées suivant l’immobilisation, les ours dormaient beaucoup plus et consacraient moins de temps à la chasse que les ours qui n’avaient pas été immobilisés. Cependant, les ours qui avaient été immobilisés ont repris les mêmes habitudes de comportement et consacré le même temps à la chasse que les ours non immobilisés en dedans de deux jours, et aucun autre effet négatif sur leur comportement n’a été décelé au cours des 21 jours qui ont suivi. Nous avons eu la confirmation visuelle d’une chasse réussie par trois ours adultes dans la période de 0,4 à 2,1 jours suivant l’immobilisation, tous trois ayant réussi à faire d’autres prises dans les 24 heures qui ont suivi. Le retour aux habitudes de comportement normales, y compris l’aptitude à faire une chasse réussie, dans les 48 heures suivant l’immobilisation semble cadrer avec l’hypothèse selon laquelle les ours polaires ne subissent pas d’effets comportementaux de longue haleine après une brève immobilisation chimique à des fins de conservation et de gestion.

Demonstration of a power-recycled Michelson interferometer with Fabry-Perot arms by frontal modulation

Large-scale gravitational-wave detectors currently under construction such as the LIGO detectors use multiple-mirror resonant optical systems containing several surfaces at which the relative phase of interfering light beams must be controlled. We describe a tabletop experiment that demonstrates a scheme for extracting signals in such an interferometer corresponding to deviations from perfect interference

Exploring the divergence between self-assessment and self-monitoring

Many models of professional self-regulation call upon individual practitioners to take responsibility both for identifying the limits of their own skills and for redressing their identified limits through continuing professional development activities. Despite these expectations, a considerable literature in the domain of self-assessment has questioned the ability of the self-regulating professional to enact this process effectively. In response, authors have recently suggested that the construction of self-assessment as represented in the self-regulation literature is, itself, problematic. In this paper we report a pair of studies that examine the relationship between self-assessment (a global judgment of one’s ability in a particular domain) and self-monitoring (a moment-by-moment awareness of the likelihood that one maintains the skill/knowledge to act in a particular situation). These studies reveal that, despite poor correlations between performance and self-assessments (consistent with what is typically seen in the self-assessment literature), participant performance was strongly related to several measures of self-monitoring including: the decision to answer or defer responding to a question, the amount of time required to make that decision to answer or defer, and the confidence expressed in an answer when provided. This apparent divergence between poor overall self-assessment and effective self-monitoring is considered in terms of how the findings might inform our understanding of the cognitive mechanisms yielding both self-monitoring judgments and self-assessments and how that understanding might be used to better direct education and learning efforts

Observational Limit on Gravitational Waves from Binary Neutron Stars in the Galaxy

Using optimal matched filtering, we search 25 hours of data from the LIGO 40-meter prototype laser interferometric gravitational-wave detector for gravitational-wave chirps emitted by coalescing binary systems within our Galaxy. This is the first test of this filtering technique on real interferometric data. An upper limit on the rate R of neutron star binary inspirals in our Galaxy is obtained: with 90% confidence, R< 0.5/hour. Similar experiments with LIGO interferometers will provide constraints on the population of tight binary neutron star systems in the Universe.Comment: RevTeX, minor revisions, exactly as published in PRL 83 (1999) p1498, 4 pages, 2 figures include

Developing effective practice learning for tomorrow's social workers

This paper considers some of the changes in social work education in the UK, particularly focusing on practice learning in England. The changes and developments are briefly identified and examined in the context of what we know about practice learning. The paper presents some findings from a small scale qualitative study of key stakeholders involved in practice learning and education in social work and their perceptions of these anticipated changes, which are revisited at implementation. The implications for practice learning are discussed

Climate change threatens polar bear populations : a stochastic demographic analysis

Author Posting. © Ecological Society of America, 2010. This article is posted here by permission of Ecological Society of America for personal use, not for redistribution. The definitive version was published in Ecology 91 (2010): 2883–2897, doi:10.1890/09-1641.1.The polar bear (Ursus maritimus) depends on sea ice for feeding, breeding, and movement. Significant reductions in Arctic sea ice are forecast to continue because of climate warming. We evaluated the impacts of climate change on polar bears in the southern Beaufort Sea by means of a demographic analysis, combining deterministic, stochastic, environment-dependent matrix population models with forecasts of future sea ice conditions from IPCC general circulation models (GCMs). The matrix population models classified individuals by age and breeding status; mothers and dependent cubs were treated as units. Parameter estimates were obtained from a capture–recapture study conducted from 2001 to 2006. Candidate statistical models allowed vital rates to vary with time and as functions of a sea ice covariate. Model averaging was used to produce the vital rate estimates, and a parametric bootstrap procedure was used to quantify model selection and parameter estimation uncertainty. Deterministic models projected population growth in years with more extensive ice coverage (2001–2003) and population decline in years with less ice coverage (2004–2005). LTRE (life table response experiment) analysis showed that the reduction in λ in years with low sea ice was due primarily to reduced adult female survival, and secondarily to reduced breeding. A stochastic model with two environmental states, good and poor sea ice conditions, projected a declining stochastic growth rate, log λs, as the frequency of poor ice years increased. The observed frequency of poor ice years since 1979 would imply log λs ≈ − 0.01, which agrees with available (albeit crude) observations of population size. The stochastic model was linked to a set of 10 GCMs compiled by the IPCC; the models were chosen for their ability to reproduce historical observations of sea ice and were forced with “business as usual” (A1B) greenhouse gas emissions. The resulting stochastic population projections showed drastic declines in the polar bear population by the end of the 21st century. These projections were instrumental in the decision to list the polar bear as a threatened species under the U.S. Endangered Species Act.We acknowledge primary funding for model development and analysis from the U.S. Geological Survey and additional funding from the National Science Foundation (DEB-0343820 and DEB-0816514), NOAA, the Ocean Life Institute and the Arctic Research Initiative at WHOI, and the Institute of Arctic Biology at the University of Alaska–Fairbanks. Funding for the capture–recapture effort in 2001–2006 was provided by the U.S. Geological Survey, the Canadian Wildlife Service, the Department of Environment and Natural Resources of the Government of the Northwest Territories, and the Polar Continental Shelf Project, Ottawa, Canada

The Physics of LIGO

In the spring term of 1994, I organized a course at Caltech on the The Physics of LIGO (i.e., the physics of the Laser Interferometer Gravitational Wave Observatory). The course consisted of eighteen 1.5-hour-long tutorial lectures, delivered by members of the LIGO team and others, and it was aimed at advanced undergraduates and graduate students in physics, applied physics and in engineering and applied sciences and also at interested postdoctoral fellows, research staff, and faculty

The Role of the Hospice Medical Director as Observed in Interdisciplinary Team Case Reviews

Article on the role of the hospice medical director as observed in interdisciplinary team case reviews

Issues of geologically-focused situational awareness in robotic planetary missions: lessons from an analogue mission at Mistastin Lake impact structure, Labrador, Canada

Remote robotic data provides different information than that obtained from immersion in the field. This significantly affects the geological situational awareness experienced by members of a mission control science team. In order to optimize science return from planetary robotic missions, these limitations must be understood and their effects mitigated to fully leverage the field experience of scientists at mission control. Results from a 13-day analogue deployment at the Mistastin Lake impact structure in Labrador, Canada suggest that scale, relief, geological detail, and time are intertwined issues that impact the mission control science team‟s effectiveness in interpreting the geology of an area. These issues are evaluated and several mitigation options are suggested. Scale was found to be difficult to interpret without the reference of known objects, even when numerical scale data were available. For this reason, embedding intuitive scale-indicating features into image data is recommended. Since relief is not conveyed in 2D images, both 3D data and observations from multiple angles are required. Furthermore, the 3D data must be observed in animation or as anaglyphs, since without such assistance much of the relief information in 3D data is not communicated. Geological detail may also be missed due to the time required to collect, analyze, and request data. We also suggest that these issues can be addressed, in part, by an improved understanding of the operational time costs and benefits of scientific data collection. Robotic activities operate on inherently slow time-scales. This fact needs to be embraced and accommodated. Instead of focusing too quickly on the details of a target of interest, thereby potentially minimizing science return, time should be allocated at first to more broad data collection at that target, including preliminary surveys, multiple observations from various vantage points, and progressively smaller scale of focus. This operational model more closely follows techniques employed by field geologists and is fundamental to the geologic interpretation of an area. Even so, an operational time cost/benefit analyses should be carefully considered in each situation, to determine when such comprehensive data collection would maximize the science return. Finally, it should be recognized that analogue deployments cannot faithfully model the time scales of robotic planetary missions. Analogue missions are limited by the difficulty and expense of fieldwork. Thus, analogue deployments should focus on smaller aspects of robotic missions and test components in a modular way (e.g., dropping communications constraints, limiting mission scope, focusing on a specific problem, spreading the mission over several field seasons, etc.)