Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| sea ice-associated diet change increases the levels of chlorinated and brominated contaminants in polar bears. | two global environmental issues, climate change and contamination by persistent organic pollutants, represent major concerns for arctic ecosystems. yet, it is unclear how these two stressors interact in the arctic. for instance, the influence of climate-associated changes in food web structure on exposure to pollutants within arctic ecosystems is presently unknown. here, we report on recent changes in feeding ecology (1991-2007) in polar bears (ursus maritimus) from the western hudson bay subpop ... | 2009 | 19603643 |
| meningoencephalitis in a polar bear caused by equine herpesvirus 9 (ehv-9). | a 12-year-old female polar bear (ursus maritimus) developed a sudden onset of muscle tremors, erratic circling, increased blinking, head shaking, and ptyalism, which progressed to partial and generalized seizures. ancillary diagnostic tests were inconclusive, and the only significant laboratory finding was nonsuppurative pleocytosis of cerebrospinal fluid. euthanasia was elected. microscopic evaluation demonstrated multifocal, random nonsuppurative meningoencephalitis involving most prominently ... | 2009 | 19605910 |
| a body composition model to estimate mammalian energy stores and metabolic rates from body mass and body length, with application to polar bears. | many species experience large fluctuations in food availability and depend on energy from fat and protein stores for survival, reproduction and growth. body condition and, more specifically, energy stores thus constitute key variables in the life history of many species. several indices exist to quantify body condition but none can provide the amount of stored energy. to estimate energy stores in mammals, we propose a body composition model that differentiates between structure and storage of an ... | 2009 | 19617423 |
| genetic variation, relatedness, and effective population size of polar bears (ursus maritimus) in the southern beaufort sea, alaska. | polar bears (ursus maritimus) are unique among bears in that they are adapted to the arctic sea ice environment. genetic data are useful for understanding their evolution and can contribute to management. we assessed parentage and relatedness of polar bears in the southern beaufort sea, alaska, with genetic data and field observations of age, sex, and mother-offspring and sibling relationships. genotypes at 14 microsatellite dna loci for 226 bears indicate that genetic variation is comparable to ... | 2010 | 19633212 |
| variation in visitor perceptions of a polar bear enclosure based on the presence of natural vs. un-natural enrichment items. | a debate exists among modern zoo staff as to whether or not the addition of un-naturalistic enrichment takes away from, or even defeats, the educational messages designers are trying to incorporate in naturalistic exhibits. a visitor study was conducted at the central park zoo's polar bear exhibit in order to determine whether or not the type of enrichment in an enclosure actually alters guest perceptions. visitors were exposed to one of two enrichment treatments in the bear enclosure: naturalis ... | 2009 | 19681144 |
| bioaccumulation and biotransformation of brominated and chlorinated contaminants and their metabolites in ringed seals (pusa hispida) and polar bears (ursus maritimus) from east greenland. | we report on the comparative bioaccumulation, biotransformation and/or biomagnification from east greenland ringed seal (pusa hispida) blubber to polar bear (ursus maritimus) tissues (adipose, liver and brain) of various classes and congeners of persistent chlorinated and brominated contaminants and metabolic by-products: polychlorinated biphenyls (pcbs), chlordanes (chls), hydroxyl (oh-) and methylsulfonyl (meso(2)-) pcbs, polybrominated biphenyls (pbbs), oh-pbbs, polybrominated diphenyl ether ... | 2009 | 19683343 |
| implications of climate change for northern canada: freshwater, marine, and terrestrial ecosystems. | climate variability and change is projected to have significant effects on the physical, chemical, and biological components of northern canadian marine, terrestrial, and freshwater systems. as the climate continues to change, there will be consequences for biodiversity shifts and for the ranges and distribution of many species with resulting effects on availability, accessibility, and quality of resources upon which human populations rely. this will have implications for the protection and mana ... | 2009 | 19714961 |
| trichinella nativa in iceland: an example of trichinella dispersion in a frigid zone. | in most arctic and subarctic regions, trichinella nativa is a common zoonotic pathogen circulating among wild carnivores. the polar bear (ursus maritimus) is one of the most important reservoirs for t. nativa in frigid zones. in iceland, trichinella infection has never been detected in the local wildlife, despite the presence of one of the host species, the arctic fox (alopex lagopus). in 2008, one of two polar bears that had swum to iceland's coast was found to have been infected with trichinel ... | 2010 | 19732473 |
| paraparesis in a polar bear (ursus maritimus) associated with west nile virus infection. | a polar bear (ursus maritimus) housed at the toronto zoo presented with acute-onset, nonambulatory paraparesis. physical examination 24 hr after onset was otherwise unremarkable, spinal radiographs looked normal, and blood tests indicated mild dehydration. with continued deterioration in its general condition, euthanasia was elected a day later. necropsy did not reveal a cause for the major presenting clinical signs. serum collected at the time of initial examination was positive for west nile v ... | 2009 | 19746875 |
| survival and breeding of polar bears in the southern beaufort sea in relation to sea ice. | 1. observed and predicted declines in arctic sea ice have raised concerns about marine mammals. in may 2008, the us fish and wildlife service listed polar bears (ursus maritimus) - one of the most ice-dependent marine mammals - as threatened under the us endangered species act. 2. we evaluated the effects of sea ice conditions on vital rates (survival and breeding probabilities) for polar bears in the southern beaufort sea. although sea ice declines in this and other regions of the polar basin h ... | 2010 | 19754681 |
| origin of hydroxylated brominated diphenyl ethers: natural compounds or man-made flame retardants? | polybrominated diphenyl ethers (pbdes) have been widely used as flame retardants. the structurally related hydroxylated pbdes (oh-pbdes) and methoxylated pbdes (meo-pbdes) occur in precipitation, surface water, wildlife, and humans. the formation of oh-pbdes in wildlife and humans is of considerable concern due to their greater toxicities relative to pbdes and meo-pbdes. research to date suggests that oh-pbdes are formed by hydroxylation of pbdes, and meo-pbdes are then formed by methylation of ... | 2009 | 19848173 |
| reproductive performance in east greenland polar bears (ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (pbpk) modelling. | polar bears (ursus maritimus) feed mainly on ringed seal (phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (ohcs) worldwide. in east greenland, studies of ohc time trends and organ system health effects, including reproductive, were conducted during 1990-2006. however, it has been difficult to determine the nature of the effects induced by ohc exposures on wild caught polar bears using body burden ... | 2009 | 19863991 |
| polychlorinated naphthalenes in polar environments--a review. | polychlorinated naphthalenes (pcns) consist of naphthalene substituted with 1-8 chlorines, yielding 75 possible congeners. they were formerly used in industry, occur at trace levels in commercial pcb mixtures, and have current sources in combustion processes. pcns are widespread in arctic air with higher levels in the european arctic. concentrations were higher during the cold months in arctic canada and russia, but no seasonality was noted in subarctic canada and greenland. "marker" congeners i ... | 2010 | 19892388 |
| exposure and effects assessment of persistent organohalogen contaminants in arctic wildlife and fish. | persistent organic pollutants (pops) encompass an array of anthropogenic organic and elemental substances and their degradation and metabolic byproducts that have been found in the tissues of exposed animals, especially pops categorized as organohalogen contaminants (ohcs). ohcs have been of concern in the circumpolar arctic for decades. for example, as a consequence of bioaccumulation and in some cases biomagnification of legacy (e.g., chlorinated pcbs, ddts and chls) and emerging (e.g., bromin ... | 2010 | 19910021 |
| mercury-associated dna hypomethylation in polar bear brains via the luminometric methylation assay: a sensitive method to study epigenetics in wildlife. | in this paper we describe a novel approach that may shed light on the genomic dna methylation of organisms with non-resolved genomes. the luminometric methylation assay (luma) is permissive for genomic dna methylation studies of any genome as it relies on the use of methyl-sensitive and -insensitive restriction enzymes followed by polymerase extension via pyrosequencing technology. here, luma was used to characterize genomic dna methylation in the lower brain stem region from 47 polar bears subs ... | 2010 | 20002585 |
| anatomy of the white bear suppression inventory (wbsi): a review of previous findings and a new approach. | the white bear suppression inventory (wbsi; wegner & zanakos, 1994) was originally designed to assess people's inclination toward thought suppression. in this article, we provide a detailed review of previous findings on the structure of this instrument and present a study that took a new statistical approach. it involved an exploratory factor analysis of the french wbsi using the weighted least squares mean and variance estimator as well as parametric item response theory analyses. results clea ... | 2009 | 20017061 |
| why the white bear is still there: electrophysiological evidence for ironic semantic activation during thought suppression. | much research has focused on the paradoxical effects of thought suppression, leading to the viewpoint that increases in unwanted thoughts are due to an ironic monitoring process that increases the activation of the very thoughts one is trying to rid from consciousness. however, it remains unclear from behavioral findings whether suppressed thoughts become more accessible during the act of suppression. in the current study, event-related potentials were recorded while participants suppressed or e ... | 2010 | 20044982 |
| withdrawn: health effects from long-range transported contaminants in arctic top predators: an integrated review based on studies of polar bears and relevant model species. | the publisher regrets that this article is an accidental duplication of an article that has already been published, doi:10.1016/j.envint.2010.03.002. the duplicate article has therefore been withdrawn. | 2010 | 20053456 |
| acquired umbilical hernias in four captive polar bears (ursus maritimus). | umbilical hernias are a common occurrence in domestic animals and humans but have not been well documented in polar bears. surgical reduction and herniorrhaphies were performed to correct acquired hernias in the region of the umbilicus in four adult captive polar bears (ursus maritimus) housed in north american zoos. two of the four bears were clinically unaffected by their hernias prior to surgery. one bear showed signs of severe discomfort following acute enlargement of the hernia. in another ... | 2009 | 20063824 |
| bacterial diversity in faeces from polar bear (ursus maritimus) in arctic svalbard. | polar bears (ursus maritimus) are major predators in the arctic marine ecosystem, feeding mainly on seals, and living closely associated with sea ice. little is known of their gut microbial ecology and the main purpose of this study was to investigate the microbial diversity in faeces of polar bears in svalbard, norway (74-81 degrees n, 10-33 degrees e). in addition the level of blatem alleles, encoding ampicillin resistance (ampr) were determined. in total, ten samples were collected from ten i ... | 2010 | 20074323 |
| use of hyaluronidase to improve chemical immobilization of free-ranging polar bears (ursus maritimus). | we assessed the efficacy and safety of hyaluronidase to improve chemical immobilization of free-ranging polar bears (ursus maritimus) captured from helicopter by remote drug delivery along the ontario coast line of northwestern james bay and southern hudson bay during september 2005 and october 2007. we used a single blind study design in which one person prepared and loaded all darts without the shooter knowing whether hyaluronidase (150 iu per dart) or sterile water was added to the immobilizi ... | 2010 | 20090038 |
| interactive effects of catastrophizing and suppression on responses to acute pain: a test of an appraisal x emotion regulation model. | we examined whether people who tend to catastrophize about pain and who also attempt to regulate negative thoughts and feelings through suppression may represent a distinct subgroup of individuals highly susceptible to pain and distress. ninety-seven healthy normal participants underwent a 4-min ischemic pain task followed by a 2-min recovery period. self-reported pain and distress was recorded during the task and every 20 s during recovery. participants completed the pain catastrophizing scale ... | 2010 | 20101453 |
| trichinella infection in a hunting community in east greenland. | trichinella nativa infection (trichinellosis) is highly prevalent in arctic wildlife, but the human burden of trichinellosis in present-day greenland is unknown. the study aimed to determine trichinella seroprevalence in an eastern greenlandic hunting community and to evaluate risk factors for seropositivity. overall, 998 inhabitants aged 10 years in the ammassalik municipality were tested for trichinella-specific igg antibodies. background information was obtained from questionnaires. seroposit ... | 2010 | 20144253 |
| effects of thought suppression on eating behaviour in restrained and non-restrained eaters. | recent research has shown that suppressing food related thoughts can cause a subsequent increase in consumption relative to groups not suppressing, or thinking about food. the present study examined whether the effects of thought suppression on subsequent eating behaviour would interact with participants restrained eating status. one hundred and sixteen female participants were split into three groups. one third suppressed thoughts of chocolate, one third thought about chocolate and the final th ... | 2010 | 20152872 |
| complete mitochondrial genome of a pleistocene jawbone unveils the origin of polar bear. | the polar bear has become the flagship species in the climate-change discussion. however, little is known about how past climate impacted its evolution and persistence, given an extremely poor fossil record. although it is undisputed from analyses of mitochondrial (mt) dna that polar bears constitute a lineage within the genetic diversity of brown bears, timing estimates of their divergence have differed considerably. using next-generation sequencing technology, we have generated a complete, hig ... | 2010 | 20194737 |
| femoral fracture repair using a locking plate technique in an adult captive polar bear (ursus maritimus). | to report successful femoral fracture repair in a polar bear. | 2010 | 20210973 |
| 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 |
| marine mammal blubber reference and control materials for use in the determination of halogenated organic compounds and fatty acids. | the national institute of standards and technology (nist) has a diverse collection of control materials derived from marine mammal blubber, fat, and serum. standard reference material (srm) 1945 organics in whale blubber was recertified for polychlorinated biphenyl (pcb) congeners, organochlorine pesticides, and polybrominated diphenyl ether (pbde) congeners. srm 1945 has also been assigned mass fraction values for compounds not frequently determined in marine samples including toxaphene congene ... | 2010 | 20238106 |
| polar bear-beware! | 1946 | 20323676 | |
| in vitro assay shows that pcb metabolites completely saturate thyroid hormone transport capacity in blood of wild polar bears (ursus maritimus). | persistent chemicals accumulate in the arctic environment due to their chemical reactivity and physicochemical properties and polychlorinated biphenyls (pcbs) are the most concentrated pollutant class in polar bears (ursus maritimus). metabolism of pcb and polybrominated biphenyl ether (pbde) flame-retardants alter their toxicological properties and these metabolites are known to interfere with the binding of thyroid hormone (th) to transthyretin (ttr) in rodents and humans. in polar bear plasma ... | 2010 | 20345174 |
| polar bear alert! | 2010 | 20364487 | |
| health effects from long-range transported contaminants in arctic top predators: an integrated review based on studies of polar bears and relevant model species. | the aim of this review is to provide a thorough overview of the health effects from the complexed biomagnified mixture of long-range transported industrial organochlorines (ocs), polybrominated diphenyl ethers (pbdes), perfluorinated compounds (pfcs) and mercury (hg) on polar bear (ursus maritimus) health. multiple scientific studies of polar bears indicate negative relationships between exposure to these contaminants and health parameters; however, these are all of a correlative nature and do n ... | 2010 | 20398940 |
| polychlorinated biphenyls and their hydroxylated metabolites (oh-pcbs) in the blood of toothed and baleen whales stranded along japanese coastal waters. | in this study, we determined the residue levels and patterns of polychlorinated biphenyls (pcbs) and hydroxylated pcbs (oh-pcbs) in the blood from eight species of toothed whales and three species of baleen whales stranded along the japanese coast during 1999-2007. penta- through hepta-chlorinated pcb congeners were the dominant homologue groups in all cetaceans. in contrast, specific differences in the distribution of dominant oh-pcb isomers and homologues were found among the cetacean species. ... | 2010 | 20426459 |
| reduced body size and cub recruitment in polar bears associated with sea ice decline. | rates of reproduction and survival are dependent upon adequate body size and condition of individuals. declines in size and condition have provided early indicators of population decline in polar bears (ursus maritimus) near the southern extreme of their range. we tested whether patterns in body size, condition, and cub recruitment of polar bears in the southern beaufort sea of alaska were related to the availability of preferred sea ice habitats and whether these measures and habitat availabili ... | 2010 | 20437962 |
| levels and trends of poly- and perfluorinated compounds in the arctic environment. | poly- and perfluorinated organic compounds (pfcs) are ubiquitous in the arctic environment. several modeling studies have been conducted in attempt to resolve the dominant transport pathway of pfcs to the arctic-atmospheric transport of precursors versus direct transport via ocean currents. these studies are generally limited by their focus on perfluorooctanoate (pfoa) fluxes to arctic seawater and thus far have only used fluorotelomer alcohols (ftohs) and sulfonamide alcohols as inputs for vola ... | 2010 | 20493516 |
| polar bears, antibiotics, and the evolving ribosome (nobel lecture). | high-resolution structures of ribosomes, the cellular machines that translate the genetic code into proteins, revealed the decoding mechanism, detected the mrna path, identified the sites of the trna molecules in the ribosome, elucidated the position and the nature of the nascent proteins exit tunnel, illuminated the interactions of the ribosome with non-ribosomal factors, such as the initiation, release and recycling factors, and provided valuable information on ribosomal antibiotics, their bin ... | 2010 | 20535730 |
| biomonitoring in greenland: human biomarkers of exposure and effects - a short review. | since 1997 the arctic monitoring and assessment programme (amap) has produced integrated assessment reports on the status of and trends in environmental persistent organic pollutants (pops) in the arctic ecosystem. three reports on biomonitoring pops and their health risks for arctic populations were published in 1998, 2002, and 2009. | 2010 | 20572746 |
| morbillivirus and toxoplasma exposure and association with hematological parameters for southern beaufort sea polar bears: potential response to infectious agents in a sentinel species. | arctic temperatures are increasing in response to greenhouse gas forcing and polar bears have already responded to changing conditions. declines in body stature and vital rates have been linked to warming-induced loss of sea-ice. as food webs change and human activities respond to a milder arctic, exposure of polar bears and other arctic marine organisms to infectious agents may increase. because of the polar bear's status as arctic ecosystem sentinel, polar bear health could provide an index of ... | 2010 | 20607348 |
| hematology of southern beaufort sea polar bears (2005-2007): biomarker for an arctic ecosystem health sentinel. | declines in sea-ice habitats have resulted in declining stature, productivity, and survival of polar bears in some regions. with continuing sea-ice declines, negative population effects are projected to expand throughout the polar bear's range. precise causes of diminished polar bear life history performance are unknown, however, climate and sea-ice condition change are expected to adversely impact polar bear (ursus maritimus) health and population dynamics. as apex predators in the arctic, pola ... | 2010 | 20617361 |
| rickets in polar bear cubs: is there a lesson for human infants? | 2011 | 20639682 | |
| suppressing the white bears interacts with anxiety sensitivity in the prediction of mood and anxiety symptoms. | suppression is a commonly used strategy to manage unwanted thoughts by attempting to actively remove them from awareness. however, research has shown that this cognitive strategy often results in the paradoxical effect of increasing the frequency of unwanted thoughts. while the association between thought suppression and mood and anxiety symptoms has been repeatedly demonstrated, relations between this cognitive strategy and other anxiety risk factors such as anxiety sensitivity (as) are unexplo ... | 2010 | 20640051 |
| the value of a polar bear: evaluating the role of a multiple-use resource in the nunavut mixed economy. | the polar bear (ursus maritimus) is a common pool resource that contributes to both the subsistence and monetary aspects of the nunavut mixed economy through its use as food, the sale of hides in the fur trade, and sport hunt outfitting. sport hunting is more financially profitable than subsistence hunting; however, the proportion of the polar bear quota devoted to the sport hunt has become relatively stable at approximately 20% across nunavut. this ratio suggests local inuit organizations are n ... | 2010 | 20648983 |
| i suppress, therefore i smoke: effects of thought suppression on smoking behavior. | thought suppression is a method frequently employed by individuals who are trying to control their thoughts and behaviors. although this strategy is known to actually increase unwanted thoughts, it is unclear whether thought suppression also results in behavioral rebound. the study presented in this article investigated the effects of suppressing thoughts of smoking in everyday life on the number of cigarettes subsequently smoked. study participants recorded their daily cigarette intake and stre ... | 2010 | 20660892 |
| brucella species survey in polar bears (ursus maritimus) of northern alaska. | we report on the presence of specific antibodies to brucella spp. and yersinia enterocolitica in polar bears (ursus maritimus) from northern alaska (southern beaufort sea) during 2003-2006. based on numerous known stressors (e.g., climate change and loss of sea ice habitat, contaminants), there is increased concern regarding the status of polar bears. considering these changes, it is important to assess exposure to potentially pathogenic organisms and to improve understanding of transmission pat ... | 2010 | 20688674 |
| contribution of synthetic and naturally occurring organobromine compounds to bromine mass in marine organisms. | an extraction, separation, and purification method was developed for the identification and quantification of total bromine (tbr), extractable organobromine (eobr), and five classes of identified eobrs. instrumental neutron activation analysis (inaa) was utilized to quantify eobr and tbr. the method was then applied to liver samples of tuna, albatross, and polar bear collected from remote marine locations. polybrominated biphenyls (pbbs), polybrominated diphenyl ethers (pbdes), bromophenols (brp ... | 2010 | 20704201 |
| arctic reality. | the threat to the hudson bay polar bears highlights the reality of a changing climate under attack from sceptics. | 2010 | 20705539 |
| serosurvey for trichinella in polar bears (ursus maritimus) from svalbard and the barents sea. | blood samples of live-caught polar bears (ursus maritimus) from svalbard collected 1991-2000 (period 1) and 2006-2008 (period 2) and from the pack ice of the barents sea collected in period 1, were assayed for antibodies against trichinella spp. by elisa. of 54 cubs-of-the-year included in the period 1 sample, 53 were seronegative, indicating that exposure to trichinella infected meat is uncommon during the first months of life for polar bears in the svalbard region. of 30 mother-offspring pairs ... | 2010 | 20797484 |
| a screening of persistent organohalogenated contaminants in hair of east greenland polar bears. | in this pilot study, we report on levels of persistent organohalogenated contaminants (ohcs) in hair of polar bears (ursus maritimus) from east greenland sampled between 1999 and 2001. to our knowledge, this is the first study on the validation of polar bear hair as a non-invasive matrix representative of concentrations and profiles in internal organs and blood plasma. because of low sample weights (13-140mg), only major bioaccumulative ohcs were detected above the limit of quantification: five ... | 2010 | 20800875 |
| trans-generational and neonatal humoral immune responses in west greenland sledge dogs (canis familiaris) exposed to organohalogenated environmental contaminants. | previous investigations in the arctic have suggested ohc (organohalogen contaminant) induced immune toxic effects on e.g. polar bears (ursus maritimus). we therefore studied the dietary impact from minke whale blubber (balaenoptera acutorostrata), rich in polyunsaturated fatty acids and ohcs, on the humoral immunity of 7 captive west greenland sledge dog (canis familiaris) bitches and their 4 pups constituting a sentinel model species for polar bears. a control group was composed of 8 bitches an ... | 2010 | 20832100 |
| reproductive cycles of marine mammals. | marine mammals conform to the general mammalian reproductive system centered on the hypothalamic-pituitary-gonadal axis. most marine mammals are long-lived and of large body size with lesser reproductive rates than many other animals, a consequence of their interaction with the marine environment where the demands of acquiring resources from the ocean must be balanced with the need for bearing offspring in a suitable place for survival. the degree of spatial and temporal separation of these life ... | 2011 | 20869821 |
| the role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western hudson bay polar bears, 1991-2007. | adipose tissue was sampled from the western hudson bay (whb) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of pcb and ocp levels both on an individual and sum-(∑-)contaminant basis. we also determined levels and temporal trends of emerging polybrominated diphenyl ethers (pbdes), hexabromocyclododecane (hbcd), polybrominated biphenyls (pbbs) and other current-use brominated flame retardants. over the 17-year period, ∑ddt (and p,p'-dde, p,p'-ddd, p,p'-ddt) ... | 2010 | 20870269 |
| serum corticosteroid binding globulin expression is modulated by fasting in polar bears (ursus maritimus). | polar bears (ursus maritimus) from several subpopulations undergo extended fasting during the ice-free season. however, the animals appear to conserve protein despite the prolonged fasting, though the mechanisms involved are poorly understood. we hypothesized that elevated concentrations of corticosteroid binding globulin (cbg), the primary cortisol binding protein in circulation, lead to cortisol resistance and provide a mechanism for protein conservation during extended fasting. the metabolic ... | 2011 | 20883811 |
| new insights into the morphology, molecular characterization and identification of baylisascaris transfuga (ascaridida, ascarididae). | species ranked within the genus baylisascaris (ascaridida, ascarididae) have been implicated in clinical and subclinical intestinal diseases in their natural hosts (e.g., raccoons and bears) as well as in life-threatening larva migrans syndromes in a number of incidental hosts, including humans. following the diagnosis of baylisascaris transfuga infestation in two captive polar bears, living in the zoo park of pistoia (tuscany, italy), nematodes (n=300; both sexes) have been characterized by mor ... | 2010 | 20947254 |
| climate change threatens polar bear populations: a stochastic demographic analysis. | 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 ... | 2010 | 21058549 |
| biomechanical consequences of rapid evolution in the polar bear lineage. | the polar bear is the only living ursid with a fully carnivorous diet. despite a number of well-documented craniodental adaptations for a diet of seal flesh and blubber, molecular and paleontological data indicate that this morphologically distinct species evolved less than a million years ago from the omnivorous brown bear. to better understand the evolution of this dietary specialization, we used phylogenetic tests to estimate the rate of morphological specialization in polar bears. we then us ... | 2010 | 21079768 |
| effects of selective serotonin reuptake inhibitors on thought-action fusion, metacognitions, and thought suppression in obsessive-compulsive disorder. | we aimed to assess whether cognitive processes change over time in patients with obsessive-compulsive disorder (ocd) receiving selective serotonin reuptake inhibitors without cognitive behavioral therapy and to investigate the factors associated with probable cognitive changes. | 2013 | 21109243 |
| flame retardants and legacy contaminants in polar bears from alaska, canada, east greenland and svalbard, 2005-2008. | flame retardants and legacy contaminants were analyzed in adipose tissue from 11 circumpolar polar bear (ursus maritimus) subpopulations in 2005-2008 spanning alaska east to svalbard. although 37 polybrominated diphenyl ethers (pbdes), total-(α)-hexabromocyclododecane (hbcd), 2 polybrominated biphenyls (pbbs), pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy(ethane) and decabromodiphenyl ethane were screened, only 4 pbdes, total-(α-)hbcd and bb153 were c ... | 2011 | 21131049 |
| cortisol levels in hair of east greenland polar bears. | to demonstrate the ability to assess long-term hypothalamic-pituitary-adrenocortical (hpa) axis activity in polar bears (ursus maritimus), a pilot study was conducted in which cortisol concentrations was analyzed in hair from 7 female (3-19 years) and 10 male (6-19 years) east greenland polar bears sampled in 1994-2006. the hair was chosen as matrix as it is non-invasive, seasonally harmonized, and has been validated as an index of long-term changes in cortisol levels. the samples were categoriz ... | 2011 | 21144554 |
| climate change: the prospects for polar bears. | 2010 | 21164475 | |
| greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence. | on the basis of projected losses of their essential sea-ice habitats, a united states geological survey research team concluded in 2007 that two-thirds of the world's polar bears (ursus maritimus) could disappear by mid-century if business-as-usual greenhouse gas emissions continue. that projection, however, did not consider the possible benefits of greenhouse gas mitigation. a key question is whether temperature increases lead to proportional losses of sea-ice habitat, or whether sea-ice cover ... | 2010 | 21164484 |
| regional contamination versus regional dietary differences: understanding geographic variation in brominated and chlorinated contaminant levels in polar bears. | the relative contribution of regional contamination versus dietary differences to geographic variation in polar bear (ursus maritimus) contaminant levels is unknown. dietary variation between alaska, canada, east greenland, and svalbard subpopulations was assessed by muscle nitrogen and carbon stable isotope (δ(15)n, δ(13)c) and adipose fatty acid (fa) signatures relative to their main prey (ringed seals). western and southern hudson bay signatures were characterized by depleted δ(15)n and δ(13) ... | 2011 | 21166451 |
| new support for polar bears and tigers. | 2010 | 21210537 | |
| temporal trends and future predictions of mercury concentrations in northwest greenland polar bear (ursus maritimus) hair. | hair samples from 117 northwest greenland polar bears (ursus maritimus) were taken during 1892-2008 and analyzed for total mercury (hereafter hg). the sample represented 28 independent years and the aim of the study was to analyze for temporal hg trends. mercury concentrations showed yearly significant increases of 1.6-1.7% (p < 0.0001) from 1892 to 2008 and the two most recent median concentrations from 2006 and 2008 were 23- to 27-fold higher respectively than baseline level from 1300 a.d. in ... | 2011 | 21214235 |
| free energies, vacancy concentrations, and density distribution anisotropies in hard-sphere crystals: a combined density functional and simulation study. | we perform a comparative study of the free energies and the density distributions in hard-sphere crystals using monte carlo simulations and density functional theory (employing fundamental measure functionals). using a recently introduced technique [t. schilling and f. schmid, j. chem. phys. 131, 231102 (2009)] we obtain crystal free energies to a high precision. the free energies from fundamental measure theory are in good agreement with the simulation results and demonstrate the applicability ... | 2010 | 21230476 |
| milk composition in free-ranging polar bears (ursus maritimus) as a model for captive rearing milk formula. | the goals of this study were to have an improved understanding of milk composition and to help create a suitable milk formula for cubs raised in captivity. milk samples were evaluated for fat, fatty acids, carbohydrate, vitamin d(3), 25(oh)d(3), vitamin a (retinol), vitamin e (α-tocopherol), protein, and amino acids. total lipids in milk did not differ for cubs (mean ± sem = 26.60 ± 1.88 g/100 ml vs. yearlings 27.80 ± 2.20 g/100 ml). milk lipids were of 23.6% saturated fatty acid for cubs and 22 ... | 2011 | 21246608 |
| spore series winner. penguins and polar bears integrates science and literacy. | 2011 | 21273478 | |
| predicting climate change impacts on polar bear litter size. | predicting the ecological impacts of climate warming is critical for species conservation. incorporating future warming into population models, however, is challenging because reproduction and survival cannot be measured for yet unobserved environmental conditions. in this study, we use mechanistic energy budget models and data obtainable under current conditions to predict polar bear litter size under future conditions. in western hudson bay, we predict climate warming-induced litter size decli ... | 2011 | 21304515 |
| exposure to mixtures of organohalogen contaminants and associative interactions with thyroid hormones in east greenland polar bears (ursus maritimus). | we investigated the multivariate relationships between adipose tissue residue levels of 48 individual organohalogen contaminants (ohcs) and circulating thyroid hormone (th) levels in polar bears (ursus maritimus) from east greenland (1999-2001, n=62), using projection to latent structure (pls) regression for four groupings of polar bears; subadults (suba), adult females with cubs (adf_n), adult females without cubs (adf_s) and adult males (adm). in the resulting significant pls models for suba, ... | 2011 | 21345491 |
| comparative analysis of fecal microbiota and intestinal microbial metabolic activity in captive polar bears. | the composition of the intestinal microbiota depends on gut physiology and diet. ursidae possess a simple gastrointestinal system composed of a stomach, small intestine, and indistinct hindgut. this study determined the composition and stability of fecal microbiota of 3 captive polar bears by group-specific quantitative pcr and pcr-dgge (denaturing gradient gel electrophoresis) using the 16s rrna gene as target. intestinal metabolic activity was determined by analysis of short-chain fatty acids ... | 2011 | 21358758 |
| comparative hepatic microsomal biotransformation of selected pbdes, including decabromodiphenyl ether, and decabromodiphenyl ethane flame retardants in arctic marine-feeding mammals. | the present study assessed and compared the oxidative and reductive biotransformation of brominated flame retardants, including established polybrominated diphenyl ethers (pbdes) and emerging decabromodiphenyl ethane (dbdpe) using an in vitro system based on liver microsomes from various arctic marine-feeding mammals: polar bear (ursus maritimus), beluga whale (delphinapterus leucas), and ringed seal (pusa hispida), and in laboratory rat as a mammalian model species. greater depletion of fully b ... | 2011 | 21437940 |
| are terrestrial mammals the source for exposure of polar bear to brucella spp. in alaska? | 2011 | 21441203 | |
| complete mitochondrial genomes of baylisascaris schroederi, baylisascaris ailuri and baylisascaris transfuga from giant panda, red panda and polar bear. | roundworms of the genus baylisascaris are the most common parasitic nematodes of the intestinal tracts of wild mammals, and most of them have significant impacts in veterinary and public health. mitochondrial (mt) genomes provide a foundation for studying epidemiology and ecology of these parasites and therefore may be used to assist in the control of baylisascariasis. here, we determined the complete sequences of mtdnas for baylisascaris schroederi, baylisascaris ailuri and baylisascaris transf ... | 2011 | 21621593 |
| polar bear population status in the northern beaufort sea, canada, 1971-2006. | polar bears (ursus maritimus) of the northern beaufort sea (nb) population occur on the perimeter of the polar basin adjacent to the northwestern islands of the canadian arctic archipelago. sea ice converges on the islands through most of the year. we used open-population capture-recapture models to estimate population size and vital rates of polar bears between 1971 and 2006 to: (1) assess relationships between survival, sex and age, and time period; (2) evaluate the long-term importance of sea ... | 2011 | 21639050 |
| differences in mercury bioaccumulation between polar bears (ursus maritimus) from the canadian high- and sub-arctic. | polar bears (ursus maritimus) are being impacted by climate change and increased exposure to pollutants throughout their northern circumpolar range. in this study, we quantified concentrations of total mercury (thg) in the hair of polar bears from canadian high- (southern beaufort sea, sbs) and sub- (western hudson bay, whb) arctic populations. concentrations of thg in polar bears from the sbs population (14.8 ± 6.6 μg g(-1)) were significantly higher than in polar bears from whb (4.1 ± 1.0 μg g ... | 2011 | 21678897 |
| polar bears in a warming climate. | polar bears (ursus maritimus) live throughout the ice-covered waters of the circumpolar arctic, particularly in near shore annual ice over the continental shelf where biological productivity is highest. however, to a large degree under scenarios predicted by climate change models, these preferred sea ice habitats will be substantially altered. spatial and temporal sea ice changes will lead to shifts in trophic interactions involving polar bears through reduced availability and abundance of their ... | 2004 | 21680496 |
| a randomized comparison of manual versus mechanical thrombus removal in primary percutaneous coronary intervention in the treatment of st-segment elevation myocardial infarction (treat-mi). | the objective of this study was to compare the efficacy and long-term clinical outcome of manual thrombus aspiration with the export catheter (medtronic, minneapolis, mn) versus mechanical thrombus cutting/aspiration with the x-sizer system (ev3, white bear lake, mn) in primary percutaneous coronary intervention (ppci). | 2011 | 21681888 |
| spatial and temporal trends of selected trace elements in liver tissue from polar bears (ursus maritimus) from alaska, canada and greenland. | spatial trends and comparative changes in time of selected trace elements were studied in liver tissue from polar bears from ten different subpopulation locations in alaska, canadian arctic and east greenland. for nine of the trace elements (as, cd, cu, hg, mn, pb, rb, se and zn) spatial trends were investigated in 136 specimens sampled during 2005-2008 from bears from these ten subpopulations. concentrations of hg, se and as were highest in the (northern and southern) beaufort sea area and lowe ... | 2011 | 21687839 |
| density functional theory for hard-sphere mixtures: the white bear version mark ii. | in the spirit of the white bear version of fundamental measure theory we derive a new density functional for hard-sphere mixtures which is based on a recent mixture extension of the carnahan-starling equation of state. in addition to the capability to predict inhomogeneous density distributions very accurately, like the original white bear version, the new functional improves upon consistency with an exact scaled-particle theory relation in the case of the pure fluid. we examine consistency in d ... | 2006 | 21690897 |
| distribution of vitamins a (retinol) and e (α-tocopherol) in polar bear kidney: implications for biomarker studies. | vitamins a and e content of inner organs, among these the kidneys, are increasingly being used as an indicator of adverse effects caused to the organism by e.g. environmental contaminants. in general, only a renal sub sample is used for analyses, and it is thus essential to know which part of the organ to sample in order to get a representative value for this important biomarker. the aim here was to assess the distribution of vitamins a (retinol) and e (α-tocopherol) within the polar bear multir ... | 2011 | 21696805 |
| ancient hybridization and an irish origin for the modern polar bear matriline. | polar bears (ursus maritimus) are among those species most susceptible to the rapidly changing arctic climate, and their survival is of global concern. despite this, little is known about polar bear species history. future conservation strategies would significantly benefit from an understanding of basic evolutionary information, such as the timing and conditions of their initial divergence from brown bears (u.-áarctos) or their response to previous environmental change. | 2011 | 21737280 |
| heart rate variability as a marker of self-regulation. | self-regulation is central to many of the most important individual and societal problems today. we sought to determine whether the relationship between self-regulation and heart rate variability (hrv) could be replicated and extended. we hypothesized that baseline hrv would predict persistence on an anagram task, and that under conditions requiring greater self-control, hrv would increase. two groups were given the same set of difficult and unsolvable anagrams. to induce self-regulatory fatigue ... | 2011 | 21739294 |
| organochlorine and metal contaminants in traditional foods from st. lawrence island, alaska. | marine mammals (bowhead whale, walrus, and various seals) constitute the major component of the diet of the yupik people of st. lawrence island, alaska. st. lawrence island residents have higher serum concentrations of polychlorinated biphenyls (pcb) than in the general u.s. population. in order to determine potential sources, traditional food samples were collected from 2004 to 2009 and analyzed for pcbs, three chlorinated pesticides, and seven heavy metals (mercury, copper, zinc, arsenic, sele ... | 2011 | 21797772 |
| blood plasma sample preparation method for the assessment of thyroid hormone-disrupting potency in effect-directed analysis. | a sample preparation method combining solid-phase extraction (spe) and liquid-liquid extraction (lle) was developed to be used in effect-directed analysis (eda) of blood plasma. until now such a method was not available. it can be used for extraction of a broad range of thyroid hormone (th)-disruptors from plasma with high recoveries. validation of the method using spiked cow plasma showed good recoveries for hydroxylated polybrominated diphenyl ethers (oh-pbdes; 93.8 -¦ 19.5%), hydroxylated pol ... | 2011 | 21842831 |
| blood-based biomarkers of selenium and thyroid status indicate possible adverse biological effects of mercury and polychlorinated biphenyls in southern beaufort sea polar bears. | we examined biomarkers of selenium status (whole blood se; serum se; glutathione peroxidase activity) and thyroid status (concentrations and ratios of thyroxine, t4; tri-iodothyronine, t3; albumin) in polar bears to assess variations among cohorts, and relationships to circulating concentrations of contaminants. concentrations of total mercury (hg) in whole blood were similar among cohorts (prime aged males and females, older animals, ages≥16 years, and young animals, ages 1-5 years; 48.44±35. 8 ... | 2011 | 21903210 |
| setting free the bears: escape from thought suppression. | a person who is asked to think aloud while trying not to think about a white bear will typically mention the bear once a minute. so how can people suppress unwanted thoughts? this article examines a series of indirect thought suppression techniques and therapies that have been explored for their efficacy as remedies for unwanted thoughts of all kinds and that offer some potential as means for effective suppression. the strategies that have some promise include focused distraction, stress and loa ... | 2011 | 22082381 |
| temporal trend of mercury in polar bears (ursus maritimus) from svalbard using teeth as a biomonitoring tissue. | we examined the use of mercury (hg) and nitrogen and carbon stable isotopes in teeth of polar bear (ursus maritimus) from svalbard as biotracers of temporal changes in hg pollution exposure between 1964 and 2003. teeth were regarded as a good matrix of the hg exposure, and in total 87 teeth of polar bears were analysed. dental hg levels ranged from 0.6 to 72.3 ng g(-1) dry weight and increased with age during the first 10 years of life. a decreasing time trend in hg concentrations was observed o ... | 2012 | 22113146 |
| relations between childhood traumatic experiences, dissociation, and cognitive models in obsessive compulsive disorder. | previous studies have indicated that obsessive compulsive disorder (ocd) is associated with childhood traumatic experiences and higher levels of dissociation. dissociative tendency may arise when individual attempt to incorporate adverse experiences into cognitive schema. | 2012 | 22122656 |
| organochlorine contaminants in arctic marine food chains: identification, geographical distribution and temporal trends in polar bears. | 1988 | 22148661 | |
| toxicokinetics of mercury in blood compartments and hair of fish-fed sled dogs. | abstract: | 2011 | 22152014 |
| perseverative negative cognitive processes are associated with depression in people with long-term conditions. | perseverative negative cognitive processes, such as worry, suppression and avoidance of undesirable thoughts, have been linked to persistence and relapse of depression. such processes could account for poor treatment response though they have received little research attention in people with long-term conditions (ltcs). | 2012 | 22169527 |
| thought suppression is associated with psychological distress in homebound older adults. | engaging in thought suppression as a coping mechanism has been associated with higher rates of anxiety and depressive disorders in younger adults. homebound older adults are a population of elders experiencing poor health and high levels of depression and anxiety. it is unclear the extent to which psychological factors, such as thought suppression, are associated with distress, given that their health and disability status may be more salient. the aim of this study was to investigate thought sup ... | 2012 | 22170756 |
| persistent chlorinated cyclodiene compounds in ringed seal, polar bear, and human plasma from northern quebec, canada: identification and concentrations of photoheptachlor. | 1995 | 22200230 | |
| simultaneous determination of zolazepam and tiletamine in dog plasma by liquid chromatography coupled to a tandem mass spectrometry. | a mixture of tiletamine, a dissociative anesthetic, and zolazepam, a minor tranquilizer, has been widely used as an anesthetic or an immobilizing agent in a variety of animal species. however, interestingly, their pharmacokinetic behaviors have been published only in polar bears and pigs. in this study, we introduce a sensitive liquid chromatography/tandem mass spectrometry (lc/ms/ms) method for determining the two drugs in dog plasma. after simple protein precipitation with acetonitrile includi ... | 2012 | 22259017 |
| pcbs and oh-pcbs in polar bear mother-cub pairs: a comparative study based on plasma levels in 1998 and 2008. | the aim of this study was to examine the plasma concentrations and prevalence of polychlorinated biphenyls (pcbs) and hydroxylated pcb-metabolites (oh-pcbs) in polar bear (ursus maritimus) mothers (n=26) and their 4 months old cubs-of-the-year (n=38) from svalbard to gain insight into the mother-cub transfer, biotransformation and to evaluate the health risk associated with the exposure to these contaminants. as samplings were performed in 1997/1998 and 2008, we further investigated the differen ... | 2012 | 22264925 |
| white bear everywhere: exploring the boundaries of the attentional white bear phenomenon. | some failures of selective attention may be explained by the attentional white bear (awb) phenomenon tsal & makovski (journal of experimental psychology: human perception and performance 32:351-363, 2006), which indicates that prior knowledge of a distractor location causes attention to be actively allocated to it. the awb effect is demonstrated in a task that includes infrequent trials that involve two simultaneous dots embedded among flanker trials. the dot positioned at an expected distractor ... | 2012 | 22323061 |
| a neuroanatomical model of prefrontal inhibitory modulation of memory retrieval. | memory of past experience is essential for guiding goal-related behavior. being able to control accessibility of memory through modulation of retrieval enables humans to flexibly adapt to their environment. understanding the specific neural pathways of how this control is achieved has largely eluded cognitive neuroscience. accordingly, in the current paper i review literature that examines the overt control over retrieval in order to reduce accessibility. i first introduce three hypotheses of in ... | 2012 | 22374224 |
| mercury speciation in brain tissue of polar bears (ursus maritimus) from the canadian arctic. | methylmercury (mehg) is a neurotoxicant that has been found at elevated concentrations in the arctic ecosystem. little is known about its internal dose in wildlife such as polar bears. we measured concentrations of mercury (hg) in three different brain regions (cerebellum, frontal lobe and brain stem) of 24 polar bears collected from the nunavik, canada between 2000 and 2003. speciation of hg was measured by high performance liquid chromatography coupled to inductively coupled plasma mass spectr ... | 2012 | 22406289 |
| level and temporal trend of perfluoroalkyl acids in greenlandic inuit. | perfluoroalkyl acids (pfaas) have been detected in human blood, breast milk and umbilical cord blood across the globe. pfaas do accumulate in the marine food chain in arctic regions. in greenland, increasing pfaa concentrations were observed during 1982-2006 in ringed seals and polar bears. however, until now, no data have been reported for pfaas in greenlandic inuit. this study assesses the level and temporal trend of serum pfaas in greenlandic inuit. | 2012 | 22456049 |
| coping in long-term survivors of childhood cancer: relations to psychological distress. | the goal of this study was to describe coping strategies and their associations with psychological distress in young adult survivors of childhood cancer. | 2013 | 22461240 |
| lactational transfer of mercury and polychlorinated biphenyls in polar bears. | we examined concentrations of total mercury (thg, inorganic and methylated forms) and polychlorinated biphenyls (pcbs) in blood and milk from free-ranging southern beaufort-chukchi sea polar bears (ursus maritimus) to assess maternal transfer of contaminants during lactation and the potential health risk to nursing young. concentrations of contaminants in the blood of dependent and juvenile animals (ages 1-5 years) ranged from 35.9 to 52.2 μg kg(-1) ww for thg and 13.9 to 52.2 μg kg(-1) ww (3255 ... | 2012 | 22464860 |