| [a case of osteosarcoma in a white polar bear]. | a male polar bear was caught at the franz josef land at the age of 1 year and then lived in moscow zoo for 6 years. thickening of the distal part of the right hind limb was noted in 1993. destructive changes in the region of epymetaphysis were observed roentgenologically suggesting osteolytic osteosarcoma. the bear was euthanized and, at autopsy, the tumor had 15 cm in diameter and the distal parts of fibula and tibia were completely destroyed. numerous cavities containing blood and necrotic are ... | 2016 | 8579504 |
| microsatellite analysis of population structure in canadian polar bears. | attempts to study the genetic population structure of large mammals are often hampered by the low levels of genetic variation observed in these species. polar bears have particularly low levels of genetic variation with the result that their genetic population structure has been intractable. we describe the use of eight hypervariable microsatellite loci to study the genetic relationships between four canadian polar bear populations: the northern beaufort sea, southern beaufort sea, western hudso ... | 1995 | 7663752 |
| preliminary results of fasting on the kinetics of organochlorines in polar bears (ursus maritimus). | we determined concentrations of polychlorinated biphenyls (pcbs), chlordanes (chlors), chlorobenzenes (cbzs), hexachlorocyclohexanes (hchs), and dichlorodiphenyltrichloroethane (ddt) and its metabolites (ddd and dde) in the tissues of individual polar bears (ursus maritimus) before and after a lengthy period of fasting. polar bears are an ideal model for such studies. they undergo one of the most extreme fasts known for any mammal and are located at the top of a long food chain, thus biomagnific ... | 1995 | 7892579 |
| geographical distribution and identification of methyl sulphone pcb and dde metabolites in pooled polar bear (ursus maritimus) adipose tissue from western hemisphere arctic and subarctic regions. | the geographical distribution of methyl sulphone (meso2-) pcb and dde metabolites is unknown for any species in any region. in this study, pooled male polar bear (ursus maritimus) adipose samples from 12 arctic and subarctic regions from the bering sea to the greenland sea were analyzed for pcbs, dde, and their meso2-metabolites. each adipose pool contained from three to 27 lipid extracts prepared on an equal fat basis. the total (s-) meso2-pcb and meso2-dde levels were generally higher in the e ... | 1995 | 7892578 |
| the comforting substrate and the right brain. | the author tested the hypothesis that the comforting substrate is located in the right parietal area of the brain. sixty subjects (39 women, 21 men) were given two forced-choice tasks treated as comparison experiments. given the choice between two identical bright red balls (one on the left and one on the right), only 20% of the right-handed subjects chose the left ball (p < .01). given the choice between identical stuffed, white bears, which were described as grieving and urgently in need of co ... | 1995 | 8535387 |
| chronic thought suppression. | we conducted several tests of the idea that an inclination toward thought suppression is associated with obsessive thinking and emotional reactivity. initially, we developed a self-report measure of thought suppression through successive factor-analytic procedures and found that it exhibited acceptable internal consistency and temporal stability. this measure, the white bear suppression inventory (wbsi), was found to correlate with measures of obsessional thinking and depressive and anxious affe ... | 1994 | 7861307 |
| suppression and repression in discrepant self-other ratings: relations with thought control and cardiovascular reactivity. | individual differences in self-other disagreement may tap phenomena that have been notoriously difficult to assess. for example, subjects who believe they possess a trait while their acquaintances disagree may be exhibiting suppression. further, subjects who deny a trait while acquaintances believe it is present may be displaying repression. in the first study, both subjects and their closest friends rated the subject's hostility level. suppressors and repressors were expected to exhibit enhance ... | 1993 | 8151503 |
| individual differences in the wegner rebound effect: evidence for a moderator variable in thought rebound following thought suppression. | wegner, schneider, carter, and white in 1987 found that attempts to suppress thoughts of a white bear produced even greater preoccupation with that stimulus--a rebound effect. this effect was investigated in exp. 1 using both wegner's white bear stimulus and a more personally meaningful stimulus (an upcoming test). the rebound effect was not observed with either stimulus. exp. 2 was conducted to examine the hypothesis that this failure to replicate wegner, et al.'s rebound effect reflected indiv ... | 1993 | 8332689 |
| levels and congener pattern of pcbs in arctic fox, alopex lagopus, in svalbard. | levels and congener pattern of polychlorinated biphenyls (pcbs) were determined in samples of subcutaneous fat and liver from 27 polar foxes, alopex lagopus, caught in svalbard during the winter 1983-1984. in all the samples analysed the composition of individual pcb congeners was studied by comparison with 12 individual pcb congeners (iupac nos. 28, 52, 101, 118, 138, 153, 170, 180, 183, 194, 206 and 209). in addition, the pcb congeners nos. 99, 105, 114, 156 and 157 were determined in the fat ... | 1993 | 15091776 |
| dispersion and transport paths of toxic persistent organochlorines to the arctic--levels and consequences. | most people still consider the arctic as one of the last non-polluted regions of the world. however, recent studies have shown that the levels of organochlorines such as chlorinated pesticides, dibenzofurans and dibenzo-p-dioxins are surprisingly high in biota such as seals and polar bears from the norwegian and canadian arctic. a short review is given of our knowledge concerning levels and sources as well as consequences of the presence of persistent toxic organochlorines in the arctic. long-ra ... | 1991 | 1948014 |
| [difficult artificial rearing of a polar bear as a result of the separation of the pelvic symphysis and an infection in the upper throat area]. | | 1991 | 2015024 |
| pediatric pain and polar bears. | | 1990 | 2364336 |
| northwest territories. rabies in a polar bear. | | 1990 | 17423612 |
| organic mercury in greenland birds and mammals. | muscle, liver and kidney samples of 20 species of birds, seals, whales and polar bear were analyzed for total and organic mercury. organic mercury concentrations varied considerably between individuals. a general tendency towards age accumulation was found, together with log-linear correlations between organic mercury concentrations in the three tissues. the major part of the muscle mercury was organic (maximum concentration found was 1235 micrograms kg-1 wet wt). this also applied to liver of b ... | 1990 | 2402624 |
| ethylene glycol (antifreeze) poisoning in a free-ranging polar bear. | the bright, fluorescent pink-colored remains of a polar bear were found on an alaskan island with the gravel and snow adjacent to the bear colored bright purple. traces of fox urine and feces found nearby were also pink. the pink and purple colors were due to rhodamine b, and ethylene glycol (eg) was present in the soil under the carcass. evidence is given to suggest the bear consumed a mixture of rhodamine b and eg commonly used to mark roads and runways during snow and ice periods. such wildli ... | 1989 | 2815544 |
| myofibre changes and capsule formation in mice infected with different strains of trichinella. | mice were infected with 4 strains of trichinella with the purpose of describing muscle changes (m. gastrocnemius, diaphragma) by light and electron microscopy, paying particular attention to capsule formation in a polar bear isolate (t. no. 13). no differences in myofibre changes or capsule formation were observed between the different strains by light microscopy at 21 and 60 days post infection. ultrastructural studies of meat samples 60 day post infection with t. no. 13 revealed active capsule ... | 1989 | 2629510 |
| organochlorine contaminants in arctic marine food chains: identification, geographical distribution and temporal trends in polar bears. | | 1988 | 22148661 |
| black bears and polar bears--still metabolic marvels. | | 1987 | 3626631 |
| mercury in polar bears from alaska. | alaskan polar bear (ursus maritimus) muscle and liver samples collected in 1972 were analyzed for total mercury. bears north of alaska had more mercury than bears west of alaska. the only difference between young and adult animals was in the northern area where adults had more mercury in liver tissue than young animals. levels were probably not high enough to be a serious threat to bears. | 1987 | 3586215 |
| hepatic neoplasia in two polar bears. | | 1985 | 3001007 |
| use of yohimbine hydrochloride to reverse immobilization of polar bears by ketamine hydrochloride and xylazine hydrochloride. | yohimbine hydrochloride (yh) effectively reversed the immobilizing effects of ketamine hydrochloride (kh) combined with xylazine hydrochloride (xh) in 48 wild polar bears (ursus maritimus) handled in the summer. single intravenous doses of yh ranging between 0.029 and 0.198 mg/kg resulted in a median time of 10 min (range: 1-123 min) to post-injection recovery from kh-xh immobilization. convulsions and muscle twitching were observed in some bears after yh was administered and one death occurred. ... | 1985 | 4078975 |
| immobilization of polar bears with carfentanil. | | 1983 | 6887436 |
| freeze-resistance of trichinella cysts in polar bears from the high-arctic region of norway (svalbard). | | 1983 | 6613785 |
| body mass, temperature and cost of walking in polar bears. | body temperatures and oxygen consumption of three sub-adult polar bears (ursus maritimus) during treadmill exercise are presented. comparisons are also made with results from prior studies of polar bear locomotion. the increase in body temperature and the metabolic cost were unexpectedly high, particularly in young animals. an equation describing the cost of locomotion versus body mass shows a negative, and apparently linear relationship. a significant correlation between body temperature and ox ... | 1982 | 7180534 |
| trichinosis in a polar bear, thalarctos maritimus, from the royal melbourne zoo. | | 1982 | 7150138 |
| immobilization of polar bears (ursus maritimus, phipps) with ketamine hydrochloride and xylazine hydrochloride. | free ranging polar bears (ursus maritimus) were immobilized using a concentrated solution of 200 mg ketamine hcl and 200 mg xylazine hcl per ml. a mean dosage of 6.8 mg (n = 21) of each drug/kg body weight was successful in immobilizing polar bears older than one year and 2.8 mg (n = 6) of each drug/kg body weight was effective for cubs of the year (coy). mean induction time for bears other than coy was 13.2 min. mean induction time for coy was 2 min. bears were tractable for a minimum of 30 min ... | 1981 | 7310940 |
| pelvic inflammatory disease in the united states. incidence and trends in private practice. | the national ambulatory care survey, conducted by the national center for health statistics (rockville, md.), provides national estimates for conditions diagnosed by office-based private practitioners in the united states. the venereal disease control division of the centers for disease control (atlanta, ga.) obtained data from the national ambulatory care survey for the years 1973-1976 and analyzed the epidemiology of pelvic inflammatory disease in women who sought care from private physicians. ... | 2004 | 7256493 |
| multiple beta cell neoplasms in a polar bear: an immunohistochemical study. | a 25-year-old polar bear had multiple pancreatic islet cell adenomas and carcinomas. special staining and immunohistochemical techniques showed the neoplasms to be of beta cell origin. an association between excessive carbohydrate diet and the multiple beta cell neoplasms is suggested. | 1980 | 6102816 |
| utilization of solar radiation by polar animals: an optical model for pelts. | a summary of existing passive solar-heat conversion panels provides the basis for a definition of an ideal passive solar-heat converter. evidence for the existence of a biological greenhouse effect in certain homopolar homeothermic species is reviewed. the thermal and optical properties of homeothermic pelts, in particular those of the polar bear, are described, and a qualitative optical model of the polar bear pelt is proposed. the effectiveness of polar bear and seal pelts as solar-heat conver ... | 1980 | 20216852 |
| evaluation of fentanyl citrate, etorphine hydrochloride, and naloxone hydrochloride in captive polar bears. | | 1979 | 521360 |
| electrophoretic variation in large mammals. i. the polar bear, thalarctos maritimus. | | 1979 | 500390 |
| treatment of an acquired abdominal hernia in a polar bear (thalarctos maritimus). | a heart rate radio-transmitter was surgically implanted in the abdomen of a captive adult male polar bear (thalarctos maritimus), but within five weeks a purulent discharge was observed at the incision site. the transmitter was surgically removed along with many fragments of the fractured encapsulation material. the skin incision healed, but a large hernia remained. repeated localized trauma to the hernia sac necessitated surgical repair. | 1979 | 459038 |
| modes of thermal protection in polar bear cubs--at birth and on emergence from the den. | at birth in late december the polar bear is small (700 g), uninsulated, and helpless. it probably has a modest capacity for metabolic heat production and depends on the female and a snow den in which it is born for thermal protection. the microclimate of an artificial polar bear den was investigated at point barrow, ak, and the temperature therein found to stay around 0 degrees c provided a heat source (200 w) equivalent to an adult polar bear was introduced. when the bears desert the den in ear ... | 1979 | 434189 |
| polar bear trackingvia satellite. | | 2009 | 687726 |
| radiative surface temperatures of exercising polar bears. | | 1976 | 3313 |
| xeroradiographic visualization of trichinae in polar bear muscle. | | 1975 | 1206220 |
| radiative surface temperatures of the polar bear. | | 1974 | 4833189 |
| industrial chemicals. extraction of polychlorinated biphenyls: evaluation of a column technique applied to polar bear and seal tissue. | | 1974 | 4205312 |
| [histomorphological studies of the trichinella strain of polar bears]. | | 1971 | 5161150 |
| [helminth fauna and muscle phase of trichinellosis in polar bears from wrangel island]. | | 1971 | 5161149 |
| liver lipids of the polar bear, thalarctos maritimus. | | 1970 | 5488806 |
| polar bear milk. iv. gross composition, fatty acid, and mineral constitution. | | 1970 | 5415436 |
| pyocephalus and gastritis in a polar bear (thalarctus maritimus). | | 1969 | 5388171 |
| mitral stenosis--how not to miss it. with emphasis on the "white bear" syndrome. | | 1969 | 5346568 |
| the foetal membranes of polar bear (thalarctos maritimus). | | 1969 | 5779570 |
| [group infection with trichinella from the meat of a polar bear in the soviet arctic region]. | | 2009 | 13450973 |
| [trichinosis in polar bear (thalarctos maritimus phipps)]. | | 1957 | 13496715 |
| toxicity of polar bear liver. | | 1949 | 18141621 |
| polar bear-beware! | | 1946 | 20323676 |
| the proper name of the polar bear. | | 1899 | 17745055 |
| the proper name of the polar bear. | | 1899 | 17736015 |
| a contribution to the psychology of the polar bear (ursus maritimus lin.). | | 1886 | 17814868 |
| a veterinary perspective on one health in the arctic. | exposure to long-range transported industrial chemicals, climate change and diseases is posing a risk to the overall health and populations of arctic wildlife. since local communities are relying on the same marine food web as marine mammals in the arctic, it requires a one health approach to understand the holistic ecosystem health including that of humans. here we collect and identify gaps in the current knowledge of health in the arctic and present the veterinary perspective of one health and ... | 2017 | 29246165 |
| harvesting wildlife affected by climate change: a modelling and management approach for polar bears. | the conservation of many wildlife species requires understanding the demographic effects of climate change, including interactions between climate change and harvest, which can provide cultural, nutritional or economic value to humans.we present a demographic model that is based on the polar bearursus maritimuslife cycle and includes density-dependent relationships linking vital rates to environmental carrying capacity (k). using this model, we develop a state-dependent management framework to c ... | 2017 | 29081540 |
| immune function in arctic mammals: natural killer (nk) cell-like activity in polar bear, muskox and reindeer. | natural killer (nk) cells are a vital part of the rapid and non-specific immune defense against invading pathogens and tumor cells. this study evaluated nk cell-like activity by flow cytometry for the first time in three ecologically and culturally important arctic mammal species: polar bear (ursus maritimus), muskox (ovibos moschatus) and reindeer (rangifer tarandus). nk cell-like activity for all three species was most effective against the mouse lymphoma cell line yac-1, compared to the human ... | 2018 | 29249321 |
| emission changes dwarf the influence of feeding habits on temporal trends of per- and polyfluoroalkyl substances in two arctic top predators. | we monitored concentrations of per- and polyfluoroalkyl substances (pfass) in relation to climate-associated changes in feeding habits and food availability in polar bears (ursus maritimus) and arctic foxes (vulpes lagopus) (192 plasma and 113 liver samples, respectively) sampled from svalbard, norway, during 1997-2014. pfass concentrations became greater with increasing dietary trophic level, as bears and foxes consumed more marine as opposed to terrestrial food, and as the availability of sea ... | 2017 | 28918622 |
| evolutionary history of enigmatic bears in the tibetan plateau-himalaya region and the identity of the yeti. | although anecdotally associated with local bears (ursus arctos and u. thibetanus), the exact identity of 'hominid'-like creatures important to folklore and mythology in the tibetan plateau-himalaya region is still surrounded by mystery. recently, two purported yeti samples from the himalayas showed genetic affinity with an ancient polar bear, suggesting they may be from previously unrecognized, possibly hybrid, bear species, but this preliminary finding has been under question. we conducted a co ... | 2017 | 29187630 |
| detection and genome characterization of two novel papillomaviruses and a novel polyomavirus in tree shrew (tupaia belangeri chinensis) in china. | papillomaviruses (pvs) and polyomaviruses (pyvs) infect diverse vertebrates including human and cause a broad spectrum of outcomes from asymptomatic infection to severe disease. there has been no pv and only one pyv detected in tree shrews, though the genomic properties of tree shrews are highly similar to those of the primates. | 2019 | 30885224 |
| a brief review-epr dosimetry and the use of animal teeth as dosimeters. | the technique of electron paramagnetic resonance dosimetry using tooth enamel was established in the late 1960s, and considerable research has been conducted to learn more about the benefits of using human teeth as dosimeters for the purpose of retrospective dose reconstruction. comparatively few studies have been done which have investigated animal teeth for the same purpose. the potential exists for utilizing animal teeth as dosimeters to reconstruct doses received by a species, as well as by ... | 2018 | 30260850 |
| environmental pollutants modulate transcriptional activity of nuclear receptors of whales in vitro. | this study reports the transcriptional activity of fin (balaenoptera physalus) and blue whale (balaenoptera musculus) peroxisome proliferator-activated receptor γ (pparg), glucocorticoid receptor (gr), and thyroid hormone receptor β (thrb), when exposed to 14 persistent organic pollutants (so-called "legacy" persistent organic pollutants (pops)) and a synthetic mixture of pops, using gal4-uas-based in vitro luciferase reporter gene assays. polychlorinated biphenyls (pcbs) had both agonistic and ... | 2020 | 32212695 |
| cortical mechanisms of prioritizing selection for rejection in visual search. | in visual search, the more one knows about a target, the faster one can find it. surprisingly, target identification is also faster with knowledge about distractor-features. the latter is paradoxical, as it implies that to avoid the selection of an item, the item must somehow be selected to some degree. this conundrum has been termed the "ignoring paradox", and, to date, little is known about how the brain resolves it. here, in data from four experiments using neuromagnetic brain recordings in m ... | 2018 | 29691330 |
| energetic costs of locomotion in bears: is plantigrade locomotion energetically economical? | ursids are the largest mammals to retain a plantigrade posture. this primitive posture has been proposed to result in reduced locomotor speed and economy relative to digitigrade and unguligrade species, particularly at high speeds. previous energetics research on polar bears (ursus maritimus) found locomotor costs were more than double predictions for similarly sized quadrupedal mammals, which could be a result of their plantigrade posture or due to adaptations to their arctic marine existence. ... | 2018 | 29921569 |
| foxes (vulpes vulpes) as sentinels for parasitic zoonoses, toxoplasma gondii and trichinella nativa, in the northeastern canadian arctic. | outbreaks of toxoplasma gondii and trichinella spp. have been recurring for decades among inuit of nunavik, northeastern canada. contact with wildlife has been identified as a risk factor for inuit exposure to t. gondii, but reservoirs have yet to be confirmed based on direct detection of dna or organism. similarly, little is known about the occurrence of trichinella spp. in wildlife species of nunavik other than walrus (odobenus rosmarus) and bears (ursus americanus, ursus maritimus). foxes (vu ... | 2018 | 30370219 |
| clostridium (clostridioides) difficile shedding by polar bears (ursus maritimus) in the canadian arctic. | clostridium (clostridioides) difficile has been identified in humans and a wide range of animal species, but there has been little study of remote animal populations with limited human contact. the objective of this study was to determine the prevalence and types of c. difficile in wild and captive polar bears (ursus maritimus). fecal samples were collected from two populations of wild polar bears in nunavut canada; m'clintock channel and hudson strait (davis strait or foxe basin), as well as fr ... | 2019 | 30880150 |
| variability in marine resources affects arctic fox population dynamics. | terrestrial predators in coastal areas are often subsidized by marine foods. in order to determine the potential impact on terrestrial prey, the numerical response of predators to each food source must be determined. in winter, arctic foxes (alopex lagopus) may forage on the frozen arctic ocean and scavenge carcasses of seals killed by polar bears (ursus maritimus), but the importance of this food source and its effect on the population cycles of arctic foxes and lemmings (their primary prey) ar ... | 2003 | 30893960 |
| polar bear evolution is marked by rapid changes in gene copy number in response to dietary shift. | polar bear (ursus maritimus) and brown bear (ursus arctos) are recently diverged species that inhabit vastly differing habitats. thus, analysis of the polar bear and brown bear genomes represents a unique opportunity to investigate the evolutionary mechanisms and genetic underpinnings of rapid ecological adaptation in mammals. copy number (cn) differences in genomic regions between closely related species can underlie adaptive phenotypes and this form of genetic variation has not been explored i ... | 2019 | 31209046 |
| the genome of the north american brown bear or grizzly: ursus arctos ssp. horribilis. | the grizzly bear (ursus arctos ssp. horribilis) represents the largest population of brown bears in north america. its genome was sequenced using a microfluidic partitioning library construction technique, and these data were supplemented with sequencing from a nanopore-based long read platform. the final assembly was 2.33 gb with a scaffold n50 of 36.7 mb, and the genome is of comparable size to that of its close relative the polar bear (2.30 gb). an analysis using 4104 highly conserved mammali ... | 2018 | 30513700 |
| discrimination factors of carbon and nitrogen stable isotopes from diet to hair in captive large arctic carnivores of conservation concern. | stable isotope analysis is widely used to reconstruct diet, delineate trophic interactions, and determine energy pathways. such ecological inferences are based on the idea that animals are, isotopically, what they eat but with a predictable difference between the isotopic ratio of a consumer and that of its diet, coined as the discrimination factor. providing correct estimates of diet-consumer isotopic discrimination in controlled conditions is key for a robust application of the stable isotopes ... | 2018 | 30030922 |
| genomic evidence of widespread admixture from polar bears into brown bears during the last ice age. | recent genomic analyses have provided substantial evidence for past periods of gene flow from polar bears (ursus maritimus) into alaskan brown bears (ursus arctos), with some analyses suggesting a link between climate change and genomic introgression. however, because it has mainly been possible to sample bears from the present day, the timing, frequency, and evolutionary significance of this admixture remains unknown. here, we analyze genomic dna from three additional and geographically distinc ... | 2018 | 29471451 |
| can-sine dynamics in the giant panda and three other caniformia genomes. | although repeat sequences constitute about 37% of carnivore genomes, the characteristics and distribution of repeat sequences among carnivore genomes have not been fully investigated. based on the updated repbase library, we re-annotated transposable elements (tes) in four caniformia genomes (giant panda, polar bear, domestic dog, and domestic ferret) and performed a systematic, genome-wide comparison focusing on the carnivora-specific sine family, can-sines. | 2018 | 30455747 |
| synteny search identifies carnivore y chromosome for evolution of male specific genes. | the explosive accumulation of mammalian genomes has provided a valuable resource to characterize the evolution of the y chromosome. unexpectedly, the y-chromosome sequence has been characterized in only a small handful of species, with the majority being model organisms. thus, identification of y-linked scaffolds from unordered genome sequences is becoming more important. here, we used a syntenic-based approach to generate the scaffolds of the male-specific region of the y chromosome (msy) from ... | 2019 | 30019860 |
| molecular characteristics and association analysis with litter size trait for porcine klk7 gene. | kallikrein-related peptidase 7(klk7) is a tumor-related gene. in this study, the full-length coding sequence of porcine klk7 gene was cloned through rt-pcr. sequence analysis revealed that the pig klk7 gene encodes a protein of 257 amino acids which has high homology with the klk7 protein of six species: polar bear (95%), weddell seal(94%), dog (92%), pacific walrus (95%), domestic cat (92%), and amur tiger (91%). this gene is structured in five exons and four introns as revealed by computer-ass ... | 2020 | 31006337 |
| fatal hepatic sarcocystosis in a free-ranging grizzly bear cub associated with sarcocystis canis-like infection. | we describe herein fatal hepatic sarcocystosis in a free-ranging grizzly bear ( ursus arctos horribilis) cub with apicomplexan infection of the liver and brain, both demonstrating 100% homology for sarcocystis canis and s. arctosi. fatal hepatic sarcocystosis in dogs has been etiologically associated with intrahepatic schizonts of s. canis. in black and polar bears, a s. canis-like organism produces schizonts in the liver and massive hepatic necrosis. although intramuscular sarcocysts, taxa s. a ... | 2019 | 30698508 |
| analyses of key genes involved in arctic adaptation in polar bears suggest selection on both standing variation and de novo mutations played an important role. | polar bears are uniquely adapted to an arctic existence. since their relatively recent divergence from their closest living relative, brown bears, less than 500,000 years ago, the species has evolved an array of novel traits suited to its arctic lifestyle. previous studies sought to uncover the genomic underpinnings of these unique characteristics, and disclosed the genes showing the strongest signal of positive selection in the polar bear lineage. here, we survey a comprehensive dataset of 109 ... | 2020 | 32758141 |
| impacts of oil spills on arctic marine ecosystems: a quantitative and probabilistic risk assessment perspective. | oil spills resulting from maritime accidents pose a poorly understood risk to the arctic environment. we propose a novel probabilistic method to quantitatively assess these risks. our method accounts for spatiotemporally varying population distributions, the spreading of oil, and seasonally varying species-specific exposure potential and sensitivity to oil. it quantifies risk with explicit uncertainty estimates, enables one to compare risks over large geographic areas, and produces information o ... | 2020 | 31971780 |
| the unique contribution of a local response group in the field investigation and management of a trichinellosis outbreak in nunavik (québec, canada). | consumption of raw game meats is important for inuit health and well-being but may sometimes increase risk of exposure to parasites. in nunavik, following trichinellosis outbreaks in the 1980s caused by raw walrus consumption, a diagnostic test was developed for the region and offered to all inuit communities by 1997. despite this prevention program, an important trichinellosis outbreak occurred in 2013, affecting 18 inhabitants of inukjuak. | 2020 | 31637676 |
| interspecies comparison of the residue levels and profiles of persistent organic pollutants in terrestrial top predators. | serum samples from three species of living terrestrial top predators were analysed for six groups of persistent organic pollutants (pops), such as polychlorinated biphenyls (pcbs), dichlorodiphenyltrichloroethane and its metabolites (ddts), chlordane compounds (chls), hexachlorocyclohexane isomers (hchs), hexachlorobenzene (hcb) and polybrominated diphenyl ethers (pbdes). the study included three carnivore species: lion (panthera leo), hyena (hyena brunnea) and cheetah (acinonyx jubatus). all sa ... | 2020 | 32006764 |
| perfluoroalkyl substances (pfass) in white whales (delphinapterus leucas) from svalbard - a comparison of concentrations in plasma sampled 15 years apart. | the objective of the present study was to investigate recent concentrations of perfluoroalkyl substances (pfass) in white whales (delphinapterus leucas) from svalbard and compare them to concentrations found in white whales sampled from that same area 15 years ago. plasma collected from live-captured white whales from two time periods (2013-2014, n = 9, and 1996-2001, n = 11) were analysed for 19 different pfass. the 11 pfass detected included seven c8-c14 perfluoroalkyl carboxylates (pfcas) and ... | 2020 | 32302893 |
| contrasting temporal patterns of mercury, niche dynamics, and body fat indices of polar bears and ringed seals in a melting icescape. | polar bears (ursus maritimus) and ringed seals (pusa hispida) have a strong predator-prey relationship and are facing climate-associated arctic habitat loss and harmful dietary exposure to total mercury (thg) and other pollutants. however, little is known about whether both species inhabiting the same area exhibit similar temporal patterns in hg concentration, niche dynamics, and body fat indices. we used thg, δ13c, and δ15n values of western hudson bay polar bear hair (2004-2016) and ringed sea ... | 2020 | 32046488 |
| bioaccumulation and biomagnification of perfluoroalkyl acids and precursors in east greenland polar bears and their ringed seal prey. | the bioaccumulation and biomagnification of 22 major perfluoroalkyl substances (pfas) were investigated in tissues of polar bears (ursus maritimus) and their major prey species, the ringed seal (pusa hispida), from the scoresby sound region of east greenland. in polar bear liver the mean σ4pfsa (perfluoroalkyl sulfonic acid) concentration (c4, c6, c8 and c10) was 2611 ± 202 ng/g wet weight (ww; 99% perfluorooctane sulfonate (pfos)) and two orders of magnitude higher than the 20 ± 3 ng/g ww (89% ... | 2019 | 31252131 |
| evidence of intraspecific prey switching: stage-structured predation of polar bears on ringed seals. | prey switching is a phenomenon in which a predator disproportionately consumes the most abundant prey type, and switches to preferentially consume another prey type if the first becomes relatively rare. this concept may be expanded outside of its usual usage describing switching between prey species (interspecific), to describe switching between prey stages within a given species (intraspecific). polar bears (ursus maritimus) are thought to seek out naive ringed seal (pusa hispida) pups in the s ... | 2019 | 30456487 |
| organophosphate esters in east greenland polar bears and ringed seals: adipose tissue concentrations and in vitro depletion and metabolite formation. | east greenland is a contamination "hot spot" for long-range transported anthropogenic chemicals, including organophosphate esters (opes). high concentrations of opes have been reported in arctic air while very little is known for wildlife where ope tissue residues levels appear to be strongly influenced by biotransformation. in the present study, the hepatic in vitro metabolism of six environmentally relevant organophosphate (op) triesters and corresponding op diester formation were investigated ... | 2018 | 29306196 |
| the distribution and trends of persistent organic pollutants and mercury in marine mammals from canada's eastern arctic. | arctic contaminant research in the marine environment has focused on organohalogen compounds and mercury mainly because they are bioaccumulative, persistent and toxic. this review summarizes and discusses the patterns and trends of persistent organic pollutants (pops) and mercury in ringed seals (pusa hispida) and polar bears (ursus maritimus) in the eastern canadian arctic relative to the rest of the canadian arctic. the review provides explanations for these trends and looks at the implication ... | 2018 | 29145101 |
| spring fasting behavior in a marine apex predator provides an index of ecosystem productivity. | the effects of declining arctic sea ice on local ecosystem productivity are not well understood but have been shown to vary inter-specifically, spatially, and temporally. because marine mammals occupy upper trophic levels in arctic food webs, they may be useful indicators for understanding variation in ecosystem productivity. polar bears (ursus maritimus) are apex predators that primarily consume benthic and pelagic-feeding ice-associated seals. as such, their productivity integrates sea ice con ... | 2018 | 28994242 |
| survey for equine herpesviruses in polar bears ( ursus maritimus) and exotic equids housed in us aza institutions. | infection by equine herpesvirus (ehv) strains (ehv-1, ehv-9) in ursid species, including polar bears ( ursus maritimus), has been associated with neurological disease and death. a serosurvey of captive exotic equid and polar bear populations in us association of zoos and aquaria institutions was performed to determine the prevalence of ehv strains using quantitative polymerase chain reaction (qpcr) and enzyme-linked immunosorbent assay (elisa) tests. equid species surveyed included zebra ( equus ... | 2018 | 30212313 |
| trichinella spiralis in a south american sea lion (otaria flavescens) from patagonia, argentina. | trichinella spp. from a sylvatic cycle has been found in several animal species such as pumas (puma concolor), armadillos (chaetophractus villosus), rats (rattus norvegicus), and wild boars (sus scrofa) in argentina. moreover, trichinella infection has been detected in a wide range of marine mammals around the world, including polar bears (ursus maritimus) and walruses (odobenus rosmarus). until the present time, trichinella spp. infection has not been detected in marine mammals of south america ... | 2018 | 30334078 |
| drivers and consequences of apex predator diet composition in the canadian beaufort sea. | polar bears (ursus maritimus) rely on annual sea ice as their primary habitat for hunting marine mammal prey. given their long lifespan, wide geographic distribution, and position at the top of the arctic marine food web, the diet composition of polar bears can provide insights into temporal and spatial ecosystem dynamics related to climate-mediated sea ice loss. polar bears with the greatest ecological constraints on diet composition may be most vulnerable to climate-related changes in ice cond ... | 2020 | 32897468 |
| 'will polar bears melt?' a qualitative analysis of children's questions about climate change. | climate change poses a grave threat to future generations, yet relatively little research examines children's understandings of the issue. this study examines the questions children ask about climate change - rather than their answers to adults' questions - exploring whether their questions suggest they view climate change as psychologically proximal or distant. children aged 10-12 from 14 uk schools took part in an online event, asking scientists questions in a 'climate zone'. the questions wer ... | 2020 | 32883158 |
| identifying reliable indicators of fitness in polar bears. | animal structural body size and condition are often measured to evaluate individual health, identify responses to environmental change and food availability, and relate food availability to effects on reproduction and survival. a variety of condition metrics have been developed but relationships between these metrics and vital rates are rarely validated. identifying an optimal approach to estimate the body condition of polar bears is needed to improve monitoring of their response to decline in s ... | 2020 | 32813753 |
| adipose tissue transcriptome is related to pollutant exposure in polar bear mother-cub pairs from svalbard, norway. | being at the food chain apex, polar bears (ursus maritimus) are highly contaminated with persistent organic pollutants (pops). females transfer pops to their offspring through gestation and lactation; therefore, young cubs present higher pops concentrations than their mothers. recent studies suggest that pops affect the lipid metabolism in female polar bears; however, the mechanisms and impact on their offspring remain unknown. here, we hypothesized that exposure to pops differentially alters ge ... | 2020 | 32808525 |
| the impact of in-person and video-recorded animal experiences on zoo visitors' cognition, affect, empathic concern, and conservation intent. | currently there are mixed results regarding the ability for media or more specifically video to increase a person's interest in conservation. however, there is a growing amount of evidence that in-person experiences at a zoo or aquarium can increase a person's interest in conservation. the goal of the current study was to examine the difference between an in-person experience viewing a polar bear training session and watching a video of the same experience on cognition, emotion, empathic concern ... | 2020 | 32789987 |
| climate-associated drivers of plasma cytokines and contaminant concentrations in beaufort sea polar bears (ursus maritimus). | assessing polar bear (ursus maritimus) immune function in relation to environmental stressors, including habitat change, nutritional stress, pathogen prevalence, and pollution, has been identified as critical for improved understanding of the species' health. the objectives of this study were two-fold: 1) to assess the role of climate-associated factors (habitat use, body condition) in explaining the plasma concentrations of contaminants in southern beaufort sea (sb) polar bears, and 2) to inves ... | 2020 | 32738684 |
| pictures of polar bears: using visitor employed photography to identify experience indicators in the arctic national wildlife refuge. | the purpose of this research is to apply visitor employed photography (vep) to recreation management to develop indicators of the wildlife viewing experience. vep and semi-structured interviews were used at a popular polar bear viewing destination in the arctic national wildlife refuge (arctic refuge). visitors to the arctic refuge who participated in an on-site semi-structured interview were asked to participate in a vep procedure after their visit. a sample of 24 semi-structured interviews, an ... | 2020 | 32560998 |
| comparative review of the distribution and burden of contaminants in the body of polar bears. | historical (or legacy) contaminants, such as metals and persistent organic pollutants (pops; e.g., polychlorinated biphenyls) have been measured in circumpolar subpopulations of polar bears, especially from hudson bay, east greenland, and svalbard, but substantially less is currently known about new and/or emerging contaminants such as polychlorinated naphthalenes, current-use pesticides, organotins, and polycyclic aromatic compounds (pacs). the polar bear (ursus maritimus) is an apex arctic pre ... | 2020 | 32556983 |
| comparing sea ice habitat fragmentation metrics using integrated step selection analysis. | habitat fragmentation occurs when continuous habitat gets broken up as a result of ecosystem change. while commonly studied in terrestrial ecosystems, arctic sea ice ecosystems also experience fragmentation, but are rarely studied in this context. most fragmentation analyses are conducted using patch-based metrics, which are potentially less suitable for sea ice that has gradual changes between sea ice cover, than distinct "long-term" patches. using an integrated step selection analysis, we comp ... | 2020 | 32551061 |
| per- and polyfluoroalkyl substances (pfas) neurotoxicity in sentinel and non-traditional laboratory model systems: potential utility in predicting adverse outcomes in human health. | per- and polyfluoroalkyl substances (pfas) are a class of chemicals that were widely used in manufacturing and are now present in the environment throughout the world. it is known that various pfas are quantifiable in human in blood, but potential adverse health outcomes remain unclear. sentinel and non-traditional model species are useful to study potential toxicity of pfas in order to understand the relationship between environmental and human health. here, we present a critical review of stud ... | 2020 | 32549216 |
| polish version of the white bear suppression inventory (wbsi) by wegner and zanakos: factor analysis and reliability. | the main aim of this study was to adapt a polish version of the white bear suppression inventory (wbsi), originally created by wegner and zanakos (1994) to measure chronic suppression. | 2020 | 32447361 |
| two decades of mercury concentrations in barents sea polar bears (ursus maritimus) in relation to dietary carbon, sulfur, and nitrogen. | temporal trends of total mercury (thg) were examined in female polar bear (ursus maritimus) hair (n = 199) from the barents sea in 1995-2016. in addition, hair values of stable isotopes (n = 190-197) of carbon (δ13c), sulfur (δ34s), and nitrogen (δ15n) and information on breeding status, body condition, and age were obtained. stable isotope values of carbon and sulfur reflect dietary source (e.g., marine vs terrestrial) and the nitrogen trophic level. values for δ13c and δ34s declined by -1.62 a ... | 2020 | 32410455 |
| bioinspired "skin" with cooperative thermo-optical effect for daytime radiative cooling. | energy-saving cooling materials with strong operability are desirable for sustainable thermal management. inspired by the cooperative thermo-optical effect in the fur of a polar bear, we develop a flexible, superhydrophobic, and reusable cooling "skin" by laminating a poly(dimethylsiloxane) film with a highly scattering polyethylene aerogel. owing to its high porosity (97.9%) and tailored pore size of 3.8 ± 1.4 μm, it can achieve superior solar reflectance (r̅sun ∼ 0.96) and high transparency to ... | 2020 | 32378874 |
| the stress of arctic warming on polar bears. | arctic ecosystems are changing rapidly in response to climate warming. while arctic mammals are highly evolved to these extreme environments, particularly with respect to their stress axis, some species may have limited capacity to adapt to this change. we examined changes in key components of the stress axis (cortisol and its carrier protein-corticosteroid binding globulin [cbg]) in polar bears (ursus maritimus) from western hudson bay (n = 300) over a 33 year period (1983-2015) during which ti ... | 2020 | 32364624 |