| xenoestrogenic and dioxin-like activity in blood of east greenland polar bears (ursus maritimus). | the aims of the project were to (i) extract the lipophilic persistent organic pollutants (pops) from the blood of 99 east greenland polar bears and assess the combined mixture effect on the estrogen receptor (er) and the aryl hydrocarbon receptor (ahr) mediated transactivity; (ii) to evaluate whether the receptor transactivities were associated with selected pop markers, and (iii) compare the receptor transactivities in polar bears with earlier studies on greenlandic inuit. lipophilic pops were ... | 2013 | 23648332 |
| characterization of blood lipoproteins and validation of cholesterol and triacylglycerol assays for free-ranging polar bears (ursus maritimus). | blood triacylglycerol (tg) and lipoproteins are important variables for evaluating nutritional status of wildlife, but measurements are often expensive and difficult. performance of a small, portable blood analyzer intended for human medical diagnostics was evaluated in measuring these variables in plasma and serum from free-ranging polar bears (ursus maritimus), which are experiencing nutritional stress related to sea ice loss. the analyzer accurately tracked changes in concentration of total c ... | 2013 | 23632660 |
| transthyretin-binding activity of contaminants in blood from polar bear (ursus maritimus) cubs. | we determined the transthyretin (ttr)-binding activity of blood-accumulating contaminants in blood plasma samples of approximately 4-months-old polar bear (ursus maritimus) cubs from svalbard sampled in 1998 and 2008. the ttr-binding activity was measured as thyroxine (t4)-like equivalents (t4-eqmeas). our findings show that the ttr-binding activity related to contaminant levels was significantly lower (45%) in 2008 than in 1998 (mean ± standard error of mean: 1998, 2265 ± 231 nm; 2008, 1258 ± 1 ... | 2013 | 23551254 |
| migration phenology and seasonal fidelity of an arctic marine predator in relation to sea ice dynamics. | understanding how seasonal environmental conditions affect the timing and distribution of synchronized animal movement patterns is a central issue in animal ecology. migration, a behavioural adaptation to seasonal environmental fluctuations, is a fundamental part of the life history of numerous species. however, global climate change can alter the spatiotemporal distribution of resources and thus affect the seasonal movement patterns of migratory animals. we examined sea ice dynamics relative to ... | 2013 | 23510081 |
| beyond the mean: sensitivities of the variance of population growth. | populations in variable environments are described by both a mean growth rate and a variance of stochastic population growth. increasing variance will increase the width of confidence bounds around estimates of population size, growth, probability of and time to quasi-extinction. however, traditional sensitivity analyses of stochastic matrix models only consider the sensitivity of the mean growth rate. we derive an exact method for calculating the sensitivity of the variance in population growth ... | 2013 | 26635948 |
| allocating attention to distractor locations is based on top-down expectations. | failures of selective attention may be explained by the attentional white bear (awb) hypothesis maintaining that prior knowledge of distractor location causes attentional allocation to it. the awb is demonstrated by embedding infrequent trials of two simultaneous dots among flanker trials. the dot at the expected distractor location is perceived as appearing before the dot at the expected empty location, indicating attentional allocation to expected distractor locations. a major requirement of t ... | 2013 | 23425450 |
| direct correlation function from the consistent fundamental-measure free energies for hard-sphere mixtures. | in a recent paper [phys. rev. e 86, 040102(r) (2012)], santos presented a self-consistency condition that can be used to limit the possible forms of fundamental measure theory. here, the direct correlation function, resulting from the santos functional, is derived, and it is found to be very close to the result of the white bear density functional, except near the origin where it diverges. | 2013 | 23410469 |
| using fundamental measure theory to treat the correlation function of the inhomogeneous hard-sphere fluid. | we investigate the value of the correlation function of an inhomogeneous hard-sphere fluid at contact. this quantity plays a critical role in statistical associating fluid theory, which is the basis of a number of recently developed classical density functionals. we define two averaged values for the correlation function at contact and derive formulas for each of them from the white bear version of the fundamental measure theory functional, using an assumption of thermodynamic consistency. we te ... | 2012 | 23367925 |
| a classical density-functional theory for describing water interfaces. | we develop a classical density functional for water which combines the white bear fundamental-measure theory (fmt) functional for the hard sphere fluid with attractive interactions based on the statistical associating fluid theory variable range (saft-vr). this functional reproduces the properties of water at both long and short length scales over a wide range of temperatures and is computationally efficient, comparable to the cost of fmt itself. we demonstrate our functional by applying it to s ... | 2013 | 23320706 |
| factors influencing annual fecal testosterone metabolite profiles in captive male polar bears (ursus maritimus). | the objectives of this study were to assess the effects of season, breeding activity, age and latitude on fecal testosterone metabolite concentrations in captive, adult male polar bears (ursus maritimus). fourteen polar bears from 13 north american zoos were monitored for 12-36 months, producing 25-year-long testosterone profiles. results indicated that testosterone was significantly higher during the breeding season (early january through the end of may) compared with the non-breeding season wi ... | 2012 | 23279504 |
| brain region distribution and patterns of bioaccumulative perfluoroalkyl carboxylates and sulfonates in east greenland polar bears (ursus maritimus). | the present study investigated the comparative accumulation of perfluoroalkyl acids (pfaas) in eight brain regions of polar bears (ursus maritimus, n = 19) collected in 2006 from scoresby sound, east greenland. the pfaas studied were perfluoroalkyl carboxylates (pfcas, c(6) -c(15) chain lengths) and sulfonates (c(4) , c(6) , c(8) , and c(10) chain lengths) as well as selected precursors including perfluorooctane sulfonamide. on a wet-weight basis, blood-brain barrier transport of pfaas occurred ... | 2013 | 23280712 |
| factor structure and clinical correlates of the food thought suppression inventory within treatment seeking obese women with binge eating disorder. | prior research on the relations among eating behaviors and thought suppression is limited to a measure of general thought suppression, the white bear suppression inventory. to address this limitation, researchers recently validated the food thought suppression inventory (ftsi). analyses using this measure suggest that food thought suppression is distinct from and is more predictive of eating disorder psychopathology than is general thought suppression. the ftsi, however, has not yet been validat ... | 2013 | 23265399 |
| females roam while males patrol: divergence in breeding season movements of pack-ice polar bears (ursus maritimus). | intraspecific differences in movement behaviour reflect different tactics used by individuals or sexes to favour strategies that maximize fitness. we report movement data collected from n = 23 adult male polar bears with novel ear-attached transmitters in two separate pack ice subpopulations over five breeding seasons. we compared movements with n = 26 concurrently tagged adult females, and analysed velocities, movement tortuosity, range sizes and habitat selection with respect to sex, reproduct ... | 2013 | 23222446 |
| class of consistent fundamental-measure free energies for hard-sphere mixtures. | in fundamental-measure theories the bulk excess free-energy density of a hard-sphere fluid mixture is assumed to depend on the partial number densities {ρ(i)} only through the four scaled-particle-theory variables {ξ(α)}, i.e., φ({ρ(i)})→φ({ξ(α)}). by imposing consistency conditions, it is proven here that such a dependence must necessarily have the form φ({ξ(α)})=-ξ(0)ln(1-ξ(3))+ψ(y)ξ(1)ξ(2)/(1-ξ(3)), where y≡ξ(2)(2)/12πξ(1)(1-ξ(3)) is a scaled variable and ψ(y) is an arbitrary dimensionless sc ... | 2012 | 23214514 |
| development and initial validation of the white bear suppression inventory (smoking version). | thought suppression can produce a paradoxical rebound in unwanted cognition. although interest in the role of suppression in nicotine dependence is growing quickly, a validated measure specifically assessing suppression of smoking-related thoughts does not exist. the present study describes the development of the white bear suppression inventory-smoking version (wbsi-s). | 2013 | 23178321 |
| combined and interactive effects of global climate change and toxicants on populations and communities. | increased temperature and other environmental effects of global climate change (gcc) have documented impacts on many species (e.g., polar bears, amphibians, coral reefs) as well as on ecosystem processes and species interactions (e.g., the timing of predator-prey interactions). a challenge for ecotoxicologists is to predict how joint effects of climatic stress and toxicants measured at the individual level (e.g., reduced survival and reproduction) will be manifested at the population level (e.g. ... | 2013 | 23147390 |
| three decades (1983-2010) of contaminant trends in east greenland polar bears (ursus maritimus). part 2: brominated flame retardants. | brominated flame retardants were determined in adipose tissues from 294 polar bears (ursus maritimus) sampled in east greenland in 23 of the 28years between 1983 and 2010. significant linear increases were found for sum polybrominated diphenyl ether (σpbde), bde100, bde153, and hexabromocyclododecane (hbcd). average increases of 5.0% per year (range: 2.9-7.6%/year) were found for the subadult polar bears. bde47 and bde99 concentrations did not show a significant linear trend over time, but rathe ... | 2013 | 23137556 |
| three decades (1983-2010) of contaminant trends in east greenland polar bears (ursus maritimus). part 1: legacy organochlorine contaminants. | legacy organochlorine contaminants were determined in adipose tissues from 294 polar bears (ursus maritimus) sampled in east greenland in 23 of the 28years between 1983 and 2010. of 19 major legacy contaminants and congeners (σpcb, 4 pcb congeners (cb153, 180, 170/190), σddt, p,p'-dde, p,p' -ddd and p,p'-ddt, α- and β-hexachlorocyclohexane (hch), hcb, octachlorostyrene, dieldrin, oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, heptachlor epoxide and bb-153), 18 showed statistic ... | 2013 | 23078749 |
| tissue-specific concentrations and patterns of perfluoroalkyl carboxylates and sulfonates in east greenland polar bears. | several perfluoroalkyl carboxylates (pfcas) and perfluoroalkyl sulfonates (pfsas) of varying chain length are bioaccumulative in biota. however, wildlife reports have focused on liver and with very little examination of other tissues, and thus there is a limited understanding of their distribution and potential effects in the mammalian body. in the present study, the comparative accumulation of c(6) to c(15) pfcas, c(4), c(6), c(8) and c(10) pfsas, and select precursors were examined in the live ... | 2012 | 23057644 |
| longitudinal fecal hormone analysis for monitoring reproductive activity in the female polar bear (ursus maritimus). | the objective was to identify suitable enzyme immunoassays to monitor gonadal and placental function in the female polar bear. immunoreactive progesterone, progesterone metabolite (pdg), estrogen, and androgen metabolite (t) concentrations were measured in fecal samples collected over 24 mo from captive female bears (n = 20). whereas fecal extracts produced displacement curves parallel to the standard curve for each respective steroid, t and pdg more accurately reflected reproductive events. con ... | 2012 | 23040062 |
| perfluoroalkyl substances in polar bear mother-cub pairs: a comparative study based on plasma levels from 1998 and 2008. | perfluoroalkyl substances (pfass) are protein-binding blood-accumulating contaminants that may have detrimental toxicological effects on the early phases of mammalian development. to enable an evaluation of the potential health risks of pfas exposure for polar bears (ursus maritimus), an exposure assessment was made by examining plasma levels of pfass in polar bear mothers in relation to their suckling cubs-of-the-year (~4 months old). samples were collected at svalbard in 1998 and 2008, and we ... | 2012 | 23010253 |
| influence of carbon and lipid sources on variation of mercury and other trace elements in polar bears (ursus maritimus). | in the present study, the authors investigated the influence of carbon and lipid sources on regional differences in liver trace element (as, cd, cu, total hg, mn, pb, rb, se, and zn) concentrations measured in polar bears (ursus maritimus) (n = 121) from 10 alaskan, canadian arctic, and east greenland subpopulations. carbon and lipid sources were assessed using δ(13) c in muscle tissue and fatty acid (fa) profiles in subcutaneous adipose tissue as chemical tracers. a negative relationship betwee ... | 2012 | 22987581 |
| temporal monitoring of liver and kidney lesions in contaminated east greenland polar bears (ursus maritimus) during 1999-2010. | organohalogen contaminants bioaccumulate to high concentrations in tissues of polar bears (ursus maritimus). the exposure levels are in the order to be toxic to inner organs like liver and kidney. we therefore investigated the temporal development of lesions in liver (n=115) and kidney (n=122) samples from east greenland polar bears taken over the 12 year period from 1999 to 2010. seven liver and seven kidney lesions were observed of which six were age-related. controlling for this, the analyses ... | 2012 | 22922222 |
| a potentially fatal mix of herpes in zoos. | pathogens often have a limited host range, but some can opportunistically jump to new species. anthropogenic activities that mix reservoir species with novel, hence susceptible, species can provide opportunities for pathogens to spread beyond their normal host range. furthermore, rapid evolution can produce new pathogens by mechanisms such as genetic recombination. zoos unintentionally provide pathogens with a high diversity of species from different continents and habitats assembled within a co ... | 2012 | 22902751 |
| effectiveness of association splitting in reducing unwanted intrusive thoughts in a nonclinical sample. | association splitting (as) is a novel cognitive technique, which has shown some promise for the reduction of obsessive thoughts in patients with obsessive-compulsive disorder (ocd). its effect on unwanted intrusive thoughts (uits) in the general population is yet unknown. | 2013 | 22874829 |
| east greenland and barents sea polar bears (ursus maritimus): adaptive variation between two populations using skull morphometrics as an indicator of environmental and genetic differences. | a morphometric study was conducted on four skull traits of 37 male and 18 female adult east greenland polar bears (ursus maritimus) collected 1892-1968, and on 54 male and 44 female adult barents sea polar bears collected 1950-1969. the aim was to compare differences in size and shape of the bear skulls using a multivariate approach, characterizing the variation between the two populations using morphometric traits as an indicator of environmental and genetic differences. mixture analysis testin ... | 2012 | 22804342 |
| endodontic therapy in a polar bear (ursus maritimus). | | 2012 | 22792860 |
| "take me to the water"--community and renewal among aging women: a case study of social interaction and exercise among the "polar bears" of martha's vineyard. | this article describes the values and practices of a water exercise group of middle-class, middle-aged and senior female predominantly african american vacationing members of the polar bears of martha's vineyard, massachusetts. it focuses on their holistic approach to health-physical, emotional, and spiritual-and their implementation of this approach through mentoring, play, and the use of certain african american cultural retention practices. it is based on 11 years of summer ethnographic field ... | 2012 | 22757760 |
| climate's role in polar bear past. | | 2012 | 22679079 |
| conceptual and linguistic representations of kinds and classes. | we investigate the hypothesis that our conceptual systems provide two formally distinct ways of representing categories by investigating the manner in which lexical nominals (e.g., tree, picnic table) and phrasal nominals (e.g., black bird, birds that like rice) are interpreted. four experiments found that lexical nominals may be mapped onto kind representations, whereas phrasal nominals map onto class representations but not kind representations. experiment 1 found that phrasal nominals, unlike ... | 2017 | 22671567 |
| mama grizzly and the polar bears. | | 2012 | 22653483 |
| plastics in the marine environment: the dark side of a modern gift. | plastics are cheap, strong, and durable and offer considerable benefits to humanity. they potentially can enhance the benefits that both medical and scientific technology will bestow to humankind. however, it has now been several decades since the use of plastics exploded, and we have evidence that our current approach to production, use, transport and disposal of plastic materials has caused, and is still causing serious effects on wildlife, and is not sustainable. because of frequent inappropr ... | 2012 | 22610295 |
| measuring environmental stress in east greenland polar bears, 1892-1927 and 1988-2009: what does hair cortisol tell us? | hair sampled from 96 east greenland polar bears (ursus maritimus) over the periods 1892-1927 and 1988-2009 was analyzed for cortisol as a proxy to investigate temporal patterns of environmental stress. cortisol concentration was independent of sex and age, and was found at significantly higher (p<0.001) concentrations in historical hair samples (1892-1927; n=8) relative to recent ones (1988-2009; n=88). in addition, there was a linear time trend in cortisol concentration of the recent samples (p ... | 2012 | 22572112 |
| non-invasive detection of candidate pregnancy protein biomarkers in the feces of captive polar bears (ursus maritimus). | currently, there is no method of accurately and non-invasively diagnosing pregnancy in polar bears. specific proteins may exhibit altered profiles in the feces of pregnant bears, but predicting appropriate candidate proteins to investigate is speculative at best. the objective of this study was to identify potential pregnancy biomarker proteins based on their increased abundance in the feces of pregnant polar bears compared to pseudopregnant females (controls) using two-dimensional in-gel electr ... | 2012 | 22538002 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| spore series winner. penguins and polar bears integrates science and literacy. | | 2011 | 21273478 |
| 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 |
| 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 |
| 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 |
| climate change: the prospects for polar bears. | | 2010 | 21164475 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| arctic reality. | the threat to the hudson bay polar bears highlights the reality of a changing climate under attack from sceptics. | 2010 | 20705539 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| polar bear alert! | | 2010 | 20364487 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| thought suppression failures in combat ptsd: a cognitive load hypothesis. | the present study investigated the relation between thought suppression of emotionally neutral content [i.e., wegner's (1994) "white bear"], incidental traumatic thought intrusion, and skin conductance responses in combat-related posttraumatic stress disorder (ptsd). participants included service members who either: a) had ptsd following an operation iraqi freedom deployment; b) were free of psychiatric diagnosis following deployment (combat equivalent), or c) were pre-deployed and without psych ... | 2009 | 19586619 |
| bionics in textiles: flexible and translucent thermal insulations for solar thermal applications. | solar thermal collectors used at present consist of rigid and heavy materials, which are the reasons for their immobility. based on the solar function of polar bear fur and skin, new collector systems are in development, which are flexible and mobile. the developed transparent heat insulation material consists of a spacer textile based on translucent polymer fibres coated with transparent silicone rubber. for incident light of the visible spectrum the system is translucent, but impermeable for u ... | 2009 | 19376769 |
| formal behavioral evaluation of enrichment programs on a zookeeper's schedule: a case study with a polar bear (ursus maritimus) at the bronx zoo. | we conducted a brief study of the effectiveness of environmental enrichment for a polar bear at the bronx zoo with two objectives in mind. first we wanted to determine if a novel method of collecting data that easily fits into a zookeeper's work routine would produce usable data and if so, we wanted to evaluate the effectiveness of some new items that had been purchased for enriching the polar bear in reducing his pacing behavior. observations were recorded for 119 days over a period of 5 months ... | 2010 | 19373879 |
| mindfulness-based cognitive therapy may reduce thought suppression in previously suicidal participants: findings from a preliminary study. | thought suppression is a strategy aimed at mental control that may paradoxically increase the frequency of unwanted thoughts. this preliminary study examined effects of mindfulness-based cognitive therapy (mbct) on thought suppression and depression in individuals with past depression and suicidality. | 2009 | 19254446 |
| does taurine deficiency cause metabolic bone disease and rickets in polar bear cubs raised in captivity? | rickets and fractures have been reported in captive polar bears. taurine (tau) is key for the conjugation of ursodeoxycholic acid (udca), a bile acid unique to bears. since tau-conjugated udca optimizes fat and fat-soluble vitamin absorption, we asked if tau deficiency could cause vitamin d malabsorption and lead to metabolic bone disease in captive polar bears. we measured tau levels in plasma (p) and whole blood (wb) from captive and free-ranging cubs and adults, and vitamin d3 and tau concent ... | 2009 | 19239163 |
| families in space: relatedness in the barents sea population of polar bears (ursus maritimus). | the kin structure and dispersal pattern of polar bears (ursus maritimus) of the barents sea was investigated during the spring mating season using two complementary approaches. first, individual genotypes based on the analyses of 27 microsatellite loci of 583 polar bears were related to field information gathered from 1146 bears in order to reconstruct the animals' pedigrees and to infer geographical distances between adult bears of different relatedness categories. according to the data, the me ... | 2009 | 19175504 |
| methyl mercury production and loss in arctic soil. | mercury has been found in polar bears and other top predators in the arctic at concentrations that pose a risk to the indigenous population, however, the means by which this occurs is uncertain. there has been extensive research on the atmospheric cycling of mercury but little is known about mercury cycling in arctic terrestrial ecosystems. the objective of this study was to determine whether wet sedge meadow soils within the truelove lowlands, devon island, nt, canada (75 degrees 33'n, 84 degre ... | 2009 | 19081608 |
| structural validity and reliability of the spanish version of the white bear suppression inventory (wbsi) in a sample of the general spanish population. | this paper introduces the validation of the spanish adaptation of the white bear suppression inventory (wbsi) by wegner and zanakos (1994). a sample of 833 people from the general population completed the wbsi along with other questionnaires. the exploratory factor analysis and the confirmatory factor analysis supported a two-factor solution accounting for 51.8% of the cumulative variance. this structure is comprised of the two following factors: unwanted intrusive thoughts (alpha = .87, r = .70 ... | 2008 | 18988450 |
| the experience of intrusions scale: a preliminary examination. | intrusive thoughts (i.e., unwelcome, distressing, involuntary thoughts) are prevalent in a variety of clinical conditions and are increasingly a focus of translational research. the goal of this study was to develop and preliminarily examine a brief self-report measure designed to assess clinically relevant aspects of the experience of intrusive thoughts related to a particular target. the experience of intrusions scale (eis) is a five-item measure that assesses the frequency, unpredictability, ... | 2009 | 18937103 |
| organohalogen concentrations in blood and adipose tissue of southern beaufort sea polar bears. | we analyzed 151 organohalogen chemicals (ohcs) in whole blood and subcutaneous fat of 57 polar bears sampled along the alaskan beaufort sea coast in spring, 2003. all major organochlorine pesticides, pcbs, pbdes and their congeners were assessed. concentrations of most ohcs continue to be lower among southern beaufort sea polar bears than reported for other populations. additionally, toxaphenes and related compounds were assessed in adipose tissue, and 8 perflourinated compounds (pfcs) were exam ... | 2008 | 18775556 |
| is dietary mercury of neurotoxicological concern to wild polar bears (ursus maritimus)? | polar bears (ursus maritimus) are exposed to high concentrations of mercury because they are apex predators in the arctic ecosystem. although mercury is a potent neurotoxic heavy metal, it is not known whether current exposures are of neurotoxicological concern to polar bears. we tested the hypotheses that polar bears accumulate levels of mercury in their brains that exceed the estimated lowest observable adverse effect level (20 microg/g dry wt) for mammalian wildlife and that such exposures ar ... | 2009 | 18717617 |
| effects of climate change on polar bears. | in this article, we review the effects on polar bears of global warming that have already been observed, and try to evaluate what may happen to the polar bears in the future. many researchers have predicted a wide range of impacts of climate change on polar bear demography and conditions. a predicted major reduction in sea ice habitat will reduce the availability of ice associated seals, the main prey of polar bears, and a loss and fragmentation of polar bear habitat will ultimately lead to larg ... | 2008 | 18717367 |
| global warming: polar bears and people--implications for public health preparedness and disaster medicine: a call to action. | | 2011 | 18557288 |
| polar bear numbers set to fall. | | 2008 | 18497777 |
| climate change. polar bear listing opens door to new lawsuits. | | 2008 | 18497267 |