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We fitted 173 satellite radio collars (platform transmitter terminals) to 121 adult female polar bears in the Beaufort Sea and relocated the bears 44 736 times between 1985 and 1995. We regularly resighted many instrumented bears so that we could ascertain whether changes in movements or distribution were related to reproductive status. Mean short-term movement rates were less than 2 km/h for all classes of bears. Maximum movement rates occurred in winter and early summer. In the southern Beaufort Sea (SBS), net geographic movements from the beginning to the end of each month were smaller for females with cubs of the year than for solitary females, and larger in November than in April, May, or July. In May, June, July, and August, radio-collared bears in the SBS moved north. They moved south in October. In the northern Beaufort Sea (NBS), bears moved north in June and south in March and September. Total annual movements ranged from 1406 to 6203 km. Mean total distances moved each month ranged from 79 to 420 km. Total monthly movements by SBS bears were largest in early winter and smallest in early spring. In the NBS, movements were largest in summer and smallest in winter. In the SBS, females with cubs moved less each month than other females. Annual activity areas ranged from 7264 to 596 800 km2. Monthly activity areas ranged from 88 to 9760 km2. Seasonal fidelity to activity areas of bears captured in all parts of the Beaufort Sea was strongest in summer and weakest in spring.

The National Petroleum Reserve–Alaska (NPR-A) in northeastern Alaska provides winter maternal denning habitat for polar bears ( Ursus maritimus ) and also has high potential for recoverable hydrocarbons. Denning polar bears exposed to human activities may abandon their dens before their young are able to survive the severity of Arctic winter weather. To ensure that wintertime petroleum activities do not threaten polar bears, managers need to know the distribution of landscape features in which maternal dens are likely to occur. Here, we present a map of potential denning habitat within the NPR-A. We used a fine-grain digital elevation model derived from Interferometric Synthetic Aperture Radar (IfSAR) to generate a map of putative denning habitat. We then tested the map’s ability to identify polar bear denning habitat on the landscape. Our final map correctly identified 82% of denning habitat estimated to be within the NPR-A. Mapped denning habitat comprised 19.7 km2 (0.1% of the study area) and was widely dispersed. Though mapping denning habitat with IfSAR data was as effective as mapping with the photogrammetric methods used for other regions of the Alaskan Arctic coastal plain, the use of GIS to analyze IfSAR data allowed greater objectivity and flexibility with less manual labor. Analytical advantages and performance equivalent to that of manual cartographic methods suggest that the use of IfSAR data to identify polar bear maternal denning habitat is a better management tool in the NPR-A and wherever such data may be available.

Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting, polar bears of the Beaufort Sea region are exposed to mineral and hydrocarbon extraction and related human activities such as shipping, road building, and seismic testing. As human populations increase and demands for polar bears and other arctic resources escalate, reliable estimates of survivorship of polar bears are needed to predict and manage the impacts of those activities. We used the Kaplan–Meier model to estimate annual survival (with 95% confidence intervals) for radio-collared female polar bears and their dependent young that were followed during a 12-year study in the Alaskan Beaufort Sea. Survival of adult female polar bears was higher than had been previously thought: Ŝ = 0.969 (range 0.952–0.983). If human-caused mortalities were deleted, the computed survival rate was 0.996 (0.990–1.002). Survival of young from den exit to weaning was 0.676 (0.634–0.701). Survival during the second year of life, 0.860 (0.751–0.903), was substantially higher than during the first year, 0.651 (0.610–0.675). Shooting by local hunters accounted for 85% of the documented deaths of adult female polar bears. Conversely, 90% of documented losses of young accompanying radio-collared females were not directly caused by humans. Deaths of dependent young were independent of litter size (P = 0.36), indicating that parental investment in single cubs was not different from investment in litters of two or more. Precise estimates of the survival of independent juveniles and adult males still need to be developed.

Polar bears (Ursus maritimus) have experienced substantial changes in the seasonal availability of sea ice habitat in parts of their range, including the Beaufort, Chukchi, and Bering Seas. In this study, we compared the body size, condition, and recruitment of polar bears captured in the Chukchi and Bering Seas (CS) between two periods (1986–1994 and 2008–2011) when declines in sea ice habitat occurred. In addition, we compared metrics for the CS population 2008–2011 with those of the adjacent southern Beaufort Sea (SB) population where loss in sea ice habitat has been associated with declines in body condition, size, recruitment, and survival. We evaluated how variation in body condition and recruitment were related to feeding ecology. Comparing habitat conditions between populations, there were twice as many reduced ice days over continental shelf waters per year during 2008–2011 in the SB than in the CS. CS polar bears were larger and in better condition, and appeared to have higher reproduction than SB bears. Although SB and CS bears had similar diets, twice as many bears were fasting in spring in the SB than in the CS. Between 1986–1994 and 2008–2011, body size, condition, and recruitment indices in the CS were not reduced despite a 44-day increase in the number of reduced ice days. Bears in the CS exhibited large body size, good body condition, and high indices of recruitment compared to most other populations measured to date. Higher biological productivity and prey availability in the CS relative to the SB, and a shorter recent history of reduced sea ice habitat, may explain the maintenance of condition and recruitment of CS bears. Geographic differences in the response of polar bears to climate change are relevant to range-wide forecasts for this and other ice-dependent species.

Recognition that polar bears are shared by hunters in Canada and Alaska prompted development of the “Polar Bear Management Agreement for the Southern Beaufort Sea.” Under this Agreement, the harvest of polar bears from the southern Beaufort Sea (SBS) is shared between Inupiat hunters of Alaska and Inuvialuit hunters of Canada. Quotas for each jurisdiction are to be reviewed annually in light of the best available scientific information. Ideal implementation of the Agreement has been hampered by the inability to quantify geographic overlap among bears from adjacent populations. We applied new analytical procedures to a more extensive radiotelemetry data set than has previously been available to quantify that overlap and thereby improve the efficacy of the Agreement. We constructed a grid over the eastern Chukchi Sea and Beaufort Sea and used twodimensional kernel smoothing to assign probabilities to the distributions of all instrumented bears. A cluster analysis of radio relocation data identified three relatively discrete groups or “populations” of polar bears: the SBS, Chukchi Sea (CS), and northern Beaufort Sea (NBS) populations. With kernel smoothing, we calculated relative probabilities of occurrence for individual members of each population in each cell of our grid. We estimated the uncertainty in probabilities by bootstrapping. Availability of polar bears from each population varied geographically. Near Barrow, Alaska, 50% of harvested bears are from the CS population and 50% from the SBS population. Nearly 99% of the bears taken by Kaktovik hunters are from the SBS. At Tuktoyaktuk, Northwest Territories, Canada, 50% are from the SBS and 50% from the NBS population. We displayed the occurrence of bears from each population as probabilities for each cell in our grid and as maps with contour lines delineating changes in relative probability. This new analytical approach will greatly improve the accuracy of allocating harvest quotas among hunting communities and jurisdictions while assuring that harvests remain within the bounds of sustainable yield.

Polar bears ( Ursus maritimus ) give birth during mid-winter in dens of ice and snow. Denning polar bears subjected to human disturbances may abandon dens before their altricial young can survive the rigors of the Arctic winter. Because the Arctic coastal plain of Alaska is an area of high petroleum potential and contains existing and planned oil field developments, the distribution of polar bear dens on the plain is of interest to land managers. Therefore, as part of a study of denning habitats along the entire Arctic coast of Alaska, we examined high-resolution aerial photographs (n = 1655) of the 7994 km2 coastal plain included in the Arctic National Wildlife Refuge (ANWR) and mapped 3621 km of bank habitat suitable for denning by polar bears. Such habitats were distributed uniformly and comprised 0.29% (23.2 km2) of the coastal plain between the Canning River and the Canadian border. Ground-truth sampling suggested that we had correctly identified 91.5% of bank denning habitats on the ANWR coastal plain. Knowledge of the distribution of these habitats will help facilitate informed management of human activities and minimize disruption of polar bears in maternal dens.

7 INTRODUCTION 9 METHODS 10 General Strategy 10 Spill Size, Timing, and Duration 10 Estimates of Where an Offshore Oil Spill May Go 11 Estimation of Polar Bear Numbers 14 Field Procedures 14 Analyses 14 Intersection of Oil-Spill Trajectories and Bear Densities 16 RESULTS 19 Estimation of Polar Bear Density 19 Oil-Spill Trajectories 20 Intersection of Oil-Spill Trajectories and Bear Densities 20 DISCUSSION 21 REFERENCES 24 TABLES AND FIGURES 29

Polar bears ( Ursus maritimus ) give birth to and nurture their young in dens of ice and snow. During 1999-2001, we measured the structure of 22 dens on the coastal plain of northern Alaska after polar bear families had evacuated their dens in the spring. During the summers of 2001 and 2002, we revisited the sites of 42 maternal and autumn exploratory dens and recorded characteristics of the under-snow habitat. The structure of polar bear snow dens was highly variable. Most were simple chambers with a single entrance/egress tunnel. Others had multiple chambers and additional tunnels. Thickness of snow above and below dens was highly variable, but most dens were overlain by less than 1 m of snow. Dens were located on, or associated with, pronounced landscape features (primarily coastal and river banks, but also a lake shore and an abandoned oil field gravel pad) that are readily distinguished from the surrounding terrain in summer and catch snow in early winter. Although easily identified, den landforms in northern Alaska were more subtle than den habitats in many other parts of the Arctic. The structure of polar bear dens in Alaska was strikingly similar to that of dens elsewhere and has remained largely unchanged in northern Alaska for more than 25 years. Knowledge of den structure and site characteristics will allow resource managers to identify habitats with the greatest probability of holding dens. This information may assist resource managers in preventing negative impacts of mineral exploration and extraction on polar bears.

Although sea ice loss is the primary threat to polar bears (Ursus maritimus), little can be done to mitigate its effects without global efforts to reduce greenhouse gas emissions. Other factors, however, could exacerbate the impacts of sea ice loss on polar bears, such as exposure to increased industrial activity. The Arctic Ocean has enormous oil and gas potential, and its development is expected to increase in the coming decades. Estimates of polar bear resource selection will inform managers how bears use areas slated for oil development and to help guide conservation planning. We estimated temporally-varying resource selection patterns for non-denning adult female polar bears in the Chukchi Sea population (2008–2012) at two scales (i.e., home range and weekly steps) to identify factors predictive of polar bear use throughout the year, before any offshore development. From the best models at each scale, we estimated scale-integrated resource selection functions to predict polar bear space use across th...

Context The potential for research methods to affect wildlife is an increasing concern among both scientists and the public. This topic has a particular urgency for polar bears because additional research is needed to monitor and understand population responses to rapid loss of sea ice habitat. Aims This study used data collected from polar bears sampled in the Alaska portion of the southern Beaufort Sea to investigate the potential for capture to adversely affect behaviour and vital rates. We evaluated the extent to which capture, collaring and handling may influence activity and movement days to weeks post-capture, and body mass, body condition, reproduction and survival over 6 months or more. Methods We compared post-capture activity and movement rates, and relationships between prior capture history and body mass, body condition and reproductive success. We also summarised data on capture-related mortality. Key results Individual-based estimates of activity and movement rates reached near-normal levels within 2–3 days and fully normal levels within 5 days post-capture. Models of activity and movement rates among all bears had poor fit, but suggested potential for prolonged, lower-level rate reductions. Repeated captures was not related to negative effects on body condition, reproduction or cub growth or survival. Capture-related mortality was substantially reduced after 1986, when immobilisation drugs were changed, with only 3 mortalities in 2517 captures from 1987–2013. Conclusions Polar bears in the southern Beaufort Sea exhibited the greatest reductions in activity and movement rates 3.5 days post-capture. These shorter-term, post-capture effects do not appear to have translated into any long-term effects on body condition, reproduction, or cub survival. Additionally, collaring had no effect on polar bear recovery rates, body condition, reproduction or cub survival. Implications This study provides empirical evidence that current capture-based research methods do not have long-term implications, and are not contributing to observed changes in body condition, reproduction or survival in the southern Beaufort Sea. Continued refinement of capture protocols, such as the use of low-impact dart rifles and reversible drug combinations, might improve polar bear response to capture and abate short-term reductions in activity and movement post-capture.

Polar bears ( Ursus maritimus ) give birth in dens of ice and snow to protect their altricial young. During the snow-free season, we visited 25 den sites located previously by radiotelemetry and characterized the den site physiognomy. Seven dens occurred in habitats with minimal relief. Eighteen dens (72%) were in coastal and river banks. These "banks" were identifiable on aerial photographs. We then searched high-resolution aerial photographs (n=3000) for habitats similar to those of the 18 dens. On aerial photos, we mapped 1782 km of bank habitats suitable for denning. Bank habitats comprised 0.18% of our study area between the Colville River and the Tamayariak River in northern Alaska. The final map, which correctly identified 88% of bank denning habitat in this region, will help minimize the potential for disruptions of maternal dens by winter petroleum exploration activities. Key words: aerial photography, Arctic National Wildlife Refuge, den habitat, maternal den, photo interpretation, National Petroleum Reserve – Alaska, polar bear, Prudhoe Bay, Ursus maritimus

There is concern that caribou ( Rangifer tarandus ) may avoid roads and facilities (i.e. infrastructure) in the Prudhoe Bay oil field (PBOF) in northern Alaska, and that this avoidance can have negative effects on the animals. We quantified the relationship between caribou distribution and PBOF infrastructure during the post-calving period (mid-June to mid-August) with aerial surveys from 1990 to 1995. We conducted four to eight surveys per year with complete coverage of the PBOF. We identified active oil field infrastructure and used a geographic information system (GIS) to construct ten 1 km wide concentric intervals surrounding the infrastructure. We tested whether caribou distribution is related to distance from infrastructure with a chi-squared habitat utilization-availability analysis and log-linear regression. We considered bull, calves, and total caribou of all sex/age classes separately. The habitat utilization-availability analysis indicated there was no consistent trend of attraction to or avoidance of infrastructure. Caribou frequently were more abundant than expected in the intervals close to infrastructure, and this trend was more pronounced for bulls and for total caribou of all sex/age classes than for calves. Log-linear regression (with Poisson error structure) of numbers of caribou and distance from infrastructure were also done, with and without combining data into the 1 km distance intervals. The analysis without intervals revealed no relationship between caribou distribution and distance from oil field infrastructure, or between caribou distribution and Julian date, year, or distance from the Beaufort Sea coast. The log-linear regression with caribou combined into distance intervals showed the density of bulls and total caribou of all sex/age classes declined with distance from infrastructure. Our results indicate that during the post-calving period: 1) caribou distribution is largely unrelated to distance from infrastructure; 2) caribou regularly use habitats in the PBOF; 3) caribou often occur close to infrastructure; and 4) caribou do not appear to avoid oil field infrastructure. Key words: caribou, Rangifer tarandus , caribou distribution, oil field infrastructure, petroleum development

The linkage reports of bipolar disease and chromosome 18 markers are controversial. We used the GAW10 data sets to further explore several observations: 1) a possible parent-of-origin effect with only 'paternal' pedigrees showing linkage; 2) the preponderance of women affected with bipolar disease, and 3) the possible existence of phenocopies in the bipolar data sets. We performed linkage analysis allowing for independent male/female recombination fractions. Our hypothesis was that if there is linkage only in 'paternal' pedigrees, then the lod score would maximize at low male and high female recombination fractions. We did not find such an effect in the combined data set. There was no consistent effect on the difference of male and female recombination fractions, suggesting that an effect is not detectable in this data set with this method. In addition, there is interesting evidence for a recessively inherited, highly penetrant gene in a subset of families. Allowing for higher penetrances for bipolar disease in women than in men had no effect on the lod scores. There was also not much difference in the lod scores calculated under the assumption of a phenocopy rate versus no phenocopies. From simulation studies, we would have expected some effect if there were linkage and phenocopies were present.

Hereditary factors play a major role in the etiology of idiopathic generalized epilepsies (IGEs). A trait locus (EBN1) for a rare subtype of IGEs, the benign neonatal familial convulsions, and a susceptibility gene (EEGV1) for the common human low-voltage electroencephalogram have been mapped close together with D20S19 to the chromosomal region 20q13.2. Both loci are potential candidates for the susceptibility to IGE spectra with age-related onset beyond the neonatal period. The present study tested the hypothesis that a putative susceptibility locus linked to D20S19 predisposes to spectra of IGEs with age-related onset from childhood to adolescence. Linkage analyses were conducted in 60 families ascertained through IGE patients with juvenile myoclonic epilepsy, juvenile absence epilepsy or childhood absence epilepsy. Our results provide evidence against linkage of a putative susceptibility gene for four hierarchically broadened IGE spectra with D20S19 assuming tentative single-locus genetic models. The extent of an "exclusion region" (lod scores below-2) varied from 0.5 cM up to 22 cM on either side of D20S19 depending on the trait assumed. These results are contrary to the expectation that a susceptibility gene in vicinity to D20S19 confers a common major gene effect to the expression of IGE spectra with age-related onset from childhood to adolescence.

Using satellite telemetry, we monitored the movements of an adult female polar bear ( Ursus maritimus ) as she traveled from the Alaskan Beaufort Sea coast to northern Greenland. She is the first polar bear known to depart the Beaufort Sea region for an extended period, and the first polar bear known to move between Alaska and Greenland. This bear traveled for four months across the polar basin and came within 2 degrees of the North Pole. During the first year following her capture, she traveled 5256 km. Evidence to suggest her use of maternity dens in northern Alaska and in northern Greenland demonstrates the potential for genetic exchange between two widely separate populations of polar bears. The long life spans of polar bears and the rarity of their long-range movements means the significance of interpopulation movement can be assessed after long-term monitoring of individuals. Key words: polar bear, Ursus maritimus , satellite telemetry, movements, Beaufort Sea, populations, Alaska, Greenland, polar basin

We applied linkage analysis with a sib-pair method, which also takes into account information on unaffected siblings, and family-based methods of association analysis to determine the disease affecting loci in Problem 1. Whereas the first two disease loci were correctly identified by association analysis, the sib-pair linkage method failed to detect the disease loci 3 and 4. We therefore determined the data structure and sample size necessary for demonstrating linkage to these loci.

Background The patterning cascade model of tooth morphogenesis accounts for shape development through the interaction of a small number of genes. In the model, gene expression both directs development and is controlled by the shape of developing teeth. Enamel knots (zones of nonproliferating epithelium) mark the future sites of cusps. In order to form, a new enamel knot must escape the inhibitory fields surrounding other enamel knots before crown components become spatially fixed as morphogenesis ceases. Because cusp location on a fully formed tooth reflects enamel knot placement and tooth size is limited by the cessation of morphogenesis, the model predicts that cusp expression varies with intercusp spacing relative to tooth size. Although previous studies in humans have supported the model's implications, here we directly test the model's predictions for the expression, size, and symmetry of Carabelli cusp, a variation present in many human populations. Methodology/Principal Findings In a dental cast sample of upper first molars (M1s) (187 rights, 189 lefts, and 185 antimeric pairs), we measured tooth area and intercusp distances with a Hirox digital microscope. We assessed Carabelli expression quantitatively as an area in a subsample and qualitatively using two typological schemes in the full sample. As predicted, low relative intercusp distance is associated with Carabelli expression in both right and left samples using either qualitative or quantitative measures. Furthermore, asymmetry in Carabelli area is associated with asymmetry in relative intercusp spacing. Conclusions/Significance These findings support the model's predictions for Carabelli cusp expression both across and within individuals. By comparing right-left pairs of the same individual, our data show that small variations in developmental timing or spacing of enamel knots can influence cusp pattern independently of genotype. Our findings suggest that during evolution new cusps may first appear as a result of small changes in the spacing of enamel knots relative to crown size.

Heterogeneity, both inter- and intrafamilial, represents a serious problem in linkage studies of common complex diseases. In this study we simulated different scenarios with families who phenotypically have identical diseases but who genotypically have two different forms of the disease (both forms genetic). We examined the proportion of families displaying intrafamilial heterogeneity, as a function of mode of inheritance, gene frequency, penetrance, and sampling strategies. Furthermore, we compared two different ways of analyzing linkage in these data sets: a two-locus (2L) analysis versus a one-locus (SL) analysis combined with an admixture test. Data were simulated with tight linkage between one disease locus and a marker locus; the other disease locus was not linked to a marker. Our findings are as follows: (1) In contrast to what has been proposed elsewhere to minimize heterogeneity, sampling only "high-density" pedigrees will increase the proportion of families with intrafamilial heterogeneity, especially when the two forms are relatively close in frequency. (2) When one form is dominant and one is recessive, this sampling strategy will greatly decrease the proportions of families with a recessive form and may therefore make it more difficult to detect linkage to the recessive form. (3) An SL analysis combined with an admixture test achieves about the same lod scores and estimate of the recombination fraction as does a 2L analysis. Also, a 2L analysis of a sample of families with intrafamilial heterogeneity does not perform significantly better than an SL analysis. (4) Bilineal pedigrees have little effect on the mean maximum lod score and mean maximum recombination fraction, and therefore there is little danger that including these families will lead to a false exclusion of linkage.

Black rat snakes (Elaphe o. obsoleta) are important predators of nesting birds and small mammals in fragmented landscapes. Thus, we used radiotelemetry to study movements of 32 black rat snakes at Remington Farms, Maryland, during 1988-89 to determine potential ways to minimize their depredations, Yearly home ranges were similar (P > 0.05) for males and females (x ± SE) (convex polygon, 9.49 ± 1.01 ha; 95% harmonic contour, 10.52 ± 1,24 ha), but males covered more (P < 0.05) of the home range earlier in the spring. Snakes were familiar with habitat features within their home range, returning to the same areas after prolonged absences. Snakes used forest edge, residential, hedgerow, and herbaceous/brush habitats more (P < 0.05-0.001) than expected by chance

Juvenile myoclonic epilepsy (JME) is a distinct subform of idiopathic generalized epilepsy of adolescence. Linkage studies with Bf and serologic HLA markers in families of JME patients have shown a tight linkage on chromosome 6. We present a linkage analysis with HLA-DQ restriction fragment length polymorphisms on more extended families, paying particular attention to the epilepsy type of the affected family members. We studied 21 families of JME patients with a total of 143 family members and obtained a highest logarithm of the odds (lod) score of 3.9 (theta m = 0.01, theta f = 0.01) assuming a dominant mode of inheritance and 70% penetrance when family members with JME, absence epilepsy, or epilepsy with generalized tonic-clonic seizures (GTCS) were considered as affected. When we also classified clinically normal family members with generalized spike-wave discharges in the EEG as "affected," the maximum lod score was 4.1 (theta m = 0.01, theta f = 0.3) under a dominant mode of inheritance and 90% penetrance. These findings support the conclusion that a gene locus for a group of idiopathic generalized epilepsies (JME, epilepsy with absences, and epilepsy with GTCS) maps to chromosome 6p.

The key to success in genetic studies seems to lie in defining simple clinical criteria which appear to be genetically homogeneous. With respect to epilepsy, which is certainly not a nosological entity based on one single criterion, the purpose is therefore to define clinical subtypes which are characterized by as few simple and calculable criteria as possible.

It has been suggested [3, 6] that juvenile myoclonic epilepsy (JME) may follow a polygenic threshold pattern of inheritance — specifically, with a differential sex effect, in that females are more often affected than males. However, as described below, we have examined 78 families with JME from Berlin and 27 from Los Angeles and have found no evidence to support the polygenic hypothesis for pure JME, either with or without differential thresholds for the two sexes. We could reach no conclusion when we included other epilepsies or EEG abnormalities in our definition of the trait.

The association of HLA antigens with some specific diseases has given us the opportunity to increase our understanding of these diseases. In these diseases of unknown etiology, the condition occurs more frequently in families of affected people then in the general population. The mode of inheritance is generally unknown. Association indicates that at least part of the genetic basis lies in the HLA region. The HLA region (or MHC) is located on the short arm of chromosome 6 and is composed of the A, B, C, and D locus. Linked with these loci are several loci not involved in immunological mechanisms such as genes for complement factors (C2, Bf, C4) and enzymes (phosphoglucomutase 3, PGM3; glyoxalase 1, GLO). Furthermore, the genes for susceptibility to hemochromatosis (HFE) and congenital adrenal hyperplasia (CA21 H) have been mapped to the HLA region itself.