Some Characteristics of Polar Bears Killed during Conflicts with Humans in the Northwest Territories, 1976-86

We examined 265 cases where polar bears were killed in the Northwest Territories as a result of bear-human encounters between 1 July 1976 and 30 June 1986. Age and sex of the bears, time of year and general circumstances of the cases were characterized. Subadult animals constituted 53% of the aged sample, and males accounted for 70% of the sexed bears. Subadult males represented 40% of known age and sex bears. Problem kills occurred throughout the year but were most frequent in the ice-free season (August-November). In 222 cases where circumstances surrounding the death were known, 63% were associated with Inuit on the land, 18% with settlements, 15% were industrial sites and 4% with research activities. Most problem kills (87%) were not included in the quota harvest. This mortality in excess of the quota may adversely affect some populations. Therefore, wherever possible we encourage the inclusion of problem bears on community quotas.Key words: polar bear (Ursus maritimus), problem bears, bear-human encounters, Arctic, Northwest TerritoriesMots clés: ours polaire (Ursus maririmus), ours-problèmes, rencontres entre l’homme et l’ours, Arctique, Territoires du Nord-Oues

Cardiac metastases

We report a case of esophageal cancer with symptomatic metastases to the heart; the patient was treated with short-course radiotherapy with good symptomatic relief. We reviewed the current literature regarding the epidemiology, clinical presentation, diagnostic tools, treatment modalities, and the prognosis of cardiac metastases. In this report we summarize the most recent autopsy studies (published between 1975 and 2007), in which we found an autopsy incidence of cardiac metastases of 2.3% among the general population, while the incidence among autopsies of cancer patients was 7.1%. Therefore, we share the opinion with others that there has been an increase in the incidence of cardiac metastases among cancer patients diagnosed after 1970, in comparison with the reported incidences in older series before 1970 (7.1% vs 3.8%; Kruskal-Wallis rank test; P = 0.039). Special attention was given to the role of radiotherapy in the management of cardiac metastases

A hybrid multiresolution scheme to efficiently model the structure of reionization on the largest scales

Redshifted 21-cm measurements of the structure of ionized regions that grow during reionization promise to provide a new probe of early galaxy and structure formation. One of the challenges of modelling reionization is to account both for the subhalo scale physics of galaxy formation and the regions of ionization on scales that are many orders of magnitude larger. To bridge this gap we first calculate the statistical relationship between ionizing luminosity and Mpc-scale overdensity using detailed models of galaxy formation computed using relatively small volume – (∼100 Mpc h−1)3, high-resolution dark matter simulations. We then use a Monte Carlo technique to apply this relationship to reionization of the intergalactic medium within large volume dark matter simulations – (>1 Gpc h−1)3. The resulting simulations can be used to address the contribution of very large scale clustering of galaxies to the structure of reionization, and show that volumes larger than 500 Mpc h−1 are required to probe the largest reionization features mid-way through reionization. As an example application of our technique, we demonstrate that the predicted 21-cm power spectrum amplitude and gradient could be used to determine the importance of supernovae feedback for early galaxy formation

Galaxy And Mass Assembly (GAMA): improved cosmic growth measurements using multiple tracers of large-scale structure

We present the first application of a ‘multiple-tracer’ redshift-space distortion (RSD) analysis to an observational galaxy sample, using data from the Galaxy and Mass Assembly (GAMA) survey. Our data set is an r < 19.8 magnitude-limited sample of 178 579 galaxies covering the redshift interval z < 0.5 and area 180 deg2. We obtain improvements of 10–20 per cent in measurements of the gravitational growth rate compared to a single-tracer analysis, deriving from the correlated sample variance imprinted in the distributions of the overlapping galaxy populations. We present new expressions for the covariances between the auto-power and cross-power spectra of galaxy samples that are valid for a general survey selection function and weighting scheme. We find no evidence for a systematic dependence of the measured growth rate on the galaxy tracer used, justifying the RSD modelling assumptions, and validate our results using mock catalogues from N-body simulations. For multiple tracers selected by galaxy colour, we measure normalized growth rates in two independent redshift bins fσ8(z = 0.18) = 0.36 ± 0.09 and fσ8(z = 0.38) = 0.44 ± 0.06, in agreement with standard GR gravity and other galaxy surveys at similar redshifts