• Physical Mechanisms For Variation In Pink Salmon (Oncorhynchus Gorbuscha) Survival Within The Upwelling And Downwelling Domains Of The Northeast Pacific

      Miller, Sara Elizabeth; Adkison, Milo; Criddle, Keith; Cokelet, Edward D. (Ned); Haldorson, Lewis J. (2011)
      Regional coastal conditions have a strong influence on juvenile salmon (genus Oncorhynchus) survival during their critical first months in the marine environment. Salmon survival has been thought to be favored within the downwelling domain if water column stabilities increase, whereas stability may have the opposite effect at lower latitudes. To explore this hypothesis at a local scale, we examined the relationship between stability and the characteristics of growth rate, condition, and marine survival of several stocks of pink salmon (O. gorbuscha) within Prince William Sound (PWS) and two water masses, Alaska Coastal Current and shelf, in the northern coastal Gulf of Alaska (GOA). While slower and weaker development of stratification with a deeper mixed layer depth may be more important for juvenile pink salmon survival in the Sound, earlier and stronger stratification with a shallower mixed layer depth may be more beneficial within the Gulf. As expected, stability within PWS did explain the growth rate of hatchery fish, although stability explained only a small amount of the variability and did not have the same relationship for each hatchery stock. Contrary to expectation, stability just prior to capture did not explain the variability in condition index for either hatchery or wild fish collected from within the Sound or from within either GOA water mass. When stability was below average just prior to capture within PWS, the relationship between condition index and year-class survival was positive; when stability was above-average just prior to capture, the relationship was negative. In a broader scale study, we explored the relationships between regional water column stabilities during early marine residence of pink salmon in both upwelling and downwelling domains of the northeast Pacific Ocean and marine survival rates the following year for hatchery stocks ranging from Vancouver Island, British Columbia, to Kodiak Island, Alaska. Contrary to expectation, our findings were similar between the upwelling and downwelling areas, but differed by the distance offshore. Marine survival rates of hatchery pink salmon from northern and southern stooks increased for salmon that experienced below-average stability on the inner shelf (luring early marine residence while stability effects from the outer shelf showed no consistent relationship to marine survival.
    • Physical volcanology of a sub-Plinian and phreatomagmatic eruption at Okmok Volcano, Alaska: implications for explosive mafic volcanism

      Wong, Lily J. (2004-12)
      The Middle Scoria Unit (M.S.) of Okmok Volcano is a basaltic andesite (̃54 wt. % SiO₂) fall deposit that is stratigraphically located between two caldera-forming eruptions (̃12,000 and 2050 y B.P.). Stratigraphy, geochemistry, vesicularity, and crystallinity data imply that the M.S. erupted in three phases that began with an initial phreatomagmatic phase followed by a sub-Plinian phase caused by rapid ascent of magma. The sequence culminates with short-lived Vulcanian eruptions that demonstrate a strong magmatic influence and a possible decrease in ascent rate. The M.S. covers ̃300 km² and averages about 2 m thick. Estimates from this work suggest a total eruptive volume of 1.4 km³, an eruption column ̃9- 14 km high, and a mass discharge rate of ̃8 x 10⁶ kg/s. These values correspond with the low end value of other sub-Plinian and phreatomagmatic eruptions. The changes seen in the eruptive phases of the M.S. are a result of variations in the magma dynamics and access of external water, likely from snow or ice. Evidence for recent magma-water interaction has also been observed within the current 10 km summit caldera. The occurrence of relatively large, explosive, non-caldera forming mafic eruptions indicates a notable hazard exists at Okmok Volcano.
    • Physiological adaptations for overwintering by the black-capped chickadee (Parus atricapillus) in interior Alaska (64 degrees North latitude)

      Sharbaugh, Susan Marie (1997)
      Winter in interior Alaska (64$\sp\circ$N) is characterized by short photoperiod (LD 5:19) and chronic subfreezing temperatures. These conditions present a physiological challenge to overwintering animals. This challenge increases as body size decreases. In small animals, higher surface to volume ratio and concomitant higher mass-specific metabolic rate (compared to larger animals) vastly increase energetic demand. This thesis focuses on the physiological adaptations of the smallest (12 g) overwintering bird in interior Alaska, the Black-capped Chickadee (Parus atricapillus). To determine if seasonal acclimatization of Black-capped Chickadees at high latitude differs from that of conspecifics at lower latitudes, standard metabolic rates (SMR), metabolic response to low temperature (${-}30\sp\circ$C), use of nocturnal hypothermia, body mass, fat reserves, and conductance were measured over two winters and one summer in three groups of seasonally acclimatized captive birds. Body mass and conductance did not vary with season, but furcular fat levels were higher in winter. Birds used nocturnal hypothermia when exposed to ${-}30\sp\circ$C in summer or winter. Although SMR did not vary seasonally, winter SMRs differed between the two winters studied. Nocturnal hypothermia in summer and decreased SMR during winter have not been reported in conspecifics at lower latitudes. Lipid reserves play an important role in fueling the energy demands of overwintering birds. Black-capped Chickadees exhibit a daily and seasonal cycle of fattening. At high latitudes (64$\sp\circ$N), fat to fuel an 18 hour nocturnal fast is deposited during 6 hours of daylight available for foraging. Daily fattening rates are highest in December when ambient conditions are most limiting. Activity of the fat deposition-promoting enzyme, adipose lipoprotein lipase (ALPL), was measured in furcular fat samples from seasonally acclimatized captive birds to determine its role in daily and seasonal fattening cycles. ALPL activity levels were 20-30 times higher than those previously reported for passerines. Seasonal variation in enzyme activity positively correlated with changes in fattening rates from December to April. Alaskan birds displayed the highest level of activity when compared to conspecifics at lower latitudes. All subpopulations measured exhibited activity higher than previously reported for small birds.
    • Physiological and behavioral responses of tanner crabs (Chionoecetes bairdi) to handling, emersion and temperature

      El Mejjati, Sonya Y. (2006-12)
      Commercially harvested Tanner crabs (Chionoecetes bairdi) are exposed to physical stressors during capture and sorting including changes in temperature and oxygen availability. This study characterizes the physiological and behavioral responses of Tanner crabs exposed to air (emersion) at 8 and -15°C for various durations. Concentrations of glucose and lactate in hemolymph measured between 30 and 120 min following emersion for 45 min differed between animals exposed to 8 or -15°C. Glucose concentrations were higher among animals emersed at 8°C than those exposed to -15°C within the intervals sampled. Lactate concentrations were unchanged at intervals following emersion at 8°C, while they were elevated at 120 min following emersion at -15°C. Rates of oxygen consumption (VO₂) increased immediately following 15, 30, and 45 min emersion at 8°C, whereas 30 and 45 min emersion at -15°C resulted in depressed VO₂. All crabs survived handling and emersion at 8°C, while exposure to -15°C resulted in increased mortality. Thus, differences among physiological parameters corresponded with differences in percentage survival between the two temperature treatments. While not providing a causal relationship between survival and physiology, the metabolic responses of Tanner crabs following a simulated capture protocol provide a predictive index of subsequent survival.
    • Physiological and ecological determinants of nutrient partitioning in caribou and reindeer

      Allaye-Chan, Ann C. (1991)
      The effects of season, migration, and reproduction on the adipose and protein dynamics of barren-ground caribou were determined from field collections of adult females from the Porcupine Herd. Radio-collared females recaptured over time provided data on animals of known reproductive status. Pregnant females averaged a daily loss of 50g body fat and 15g body protein during the last 60 days of gestation. Between June and September, lactating females preferentially deposited body protein but non-lactating females preferentially deposited body fat. In both cohorts, fat deposition increased relative to protein deposition in fall, but maximum fat deposition occurred in summer. Females that conceived averaged 220% more body fat and 17% more body protein than females that did not conceive. Fetal and birth weight positively correlated with maternal protein reserves, but not with maternal fat reserves. Fieldwork on free-ranging caribou were complemented with nutritional experiments on captive animals to determine the effects of energy intake, protein intake, the dietary protein:energy ratio, date, and body condition on nutrient partitioning between fat and protein deposition, and between maternal tissue deposition and milk production. In both lactating and non-lactating females, the proportion of tissue deposited as fat rather than protein increased between spring and fall but decreased with increasing fatness. Lactating and non-lactating females had comparable efficiency coefficients for net energy retention (60% and 65% respectively), but daily maintenance requirement for lactating females (456 KJ/BW$\sp{0.75}$) was twice that for non-lactating individuals (233 KJ/BW$\sp{0.75}$). Energy intake increased protein deposition in lactating females but increased fat deposition in non-lactating females. Production of milk dry matter, fat, and energy were unaffected by maternal energy intake, maternal protein intake, maternal body condition, or calf age. However, production of milk lactose correlated with maternal energy intake, while production of milk protein correlated with the maternal dietary protein:energy ratio. Prediction equations for body weight and composition of barren-ground caribou were developed using bone, muscle, fat, and organ indices. Prediction equations for body weight were validated with an independent data set.
    • Physiological and ecological implications of hemorheological variations in marine and terrestrial mammals

      Wickham, Lori Lee (1988)
      The possible significance of variations in interspecific hemorheological properties related to diving behavior was studied in eight species of marine mammals with humans and pigs as terrestrial controls. Diving duration was positively correlated with elevated blood hemoglobin, oxygen capacity and viscosity among animals of the same class. No acclimatization response to activity was evident from studies of blood drawn from newly-captured northern elephant seals and sea otters and those in captivity for extended periods which justified the use of captive animals for rheological studies. Adaptations of marine mammals to diving were evident from comparisons of phocid seal and pig hemorheology. Seals had increased oxygen storage (six times) with less viscosity-dependent reductions in oxygen transport ($-$22%) when compared to pigs at equal packed cell volume. Phocid seal blood samples were compared with those of pigs and humans for erythrocyte aggregation and blood viscoelasticity to study the mechanics of viscometric variations. Viscous and elastic components of seal blood viscosity were 20 to 73% lower than those of pigs due to decreased aggregation extent and rate (P $<$ 0.05). Lower plasma fibrinogen and increased erythrocyte electrophoretic mobility are believed to contribute to lowered seal blood aggregation. Comparisons of the in vivo effects of blood viscosity on whole body and myocardial oxygen consumption by manipulation of whole body hematocrit in seals and pigs revealed that optimal hematocrit ranges for seals were shifted to the right of those from pigs (SEALS: 25%-55%; PIGS: 25%-45%; P $<$ 0.05). Seals showed significantly less viscosity-dependence in total body oxygen transport and oxygen consumption than did pigs. Myocardial oxygen consumption data were variable and showed no statistically significant differences among seals and pigs. The seals' lower erythrocyte aggregation, decreased low-shear viscosity and a greater ability to compensate for viscosity changes may represent adaptations to reduce the stress necessary to reinitiate flow in stagnant venous sinuses thereby reducing blood-flow resistance during dive-recovery. These adaptations may help maintain circulatory perfusion to vital organs, while flow is restricted to less oxygen-dependent tissues during underwater submergence without sacrificing the advantage of increased blood oxygen storage.
    • Physiological ecology of Porphyra sporophytes: growth, photosynthesis, respiration and pigments

      Lin, Rulong (2000-05)
      Growth, photosynthesis, respiration and photosynthetic pigments of the sporophytic stage for Alaskan Porphyra species were investigated in response to various environmental variables. Optimal conchocelis growth (7.6%) volume increase d⁻¹) of P. abbottae (Pa) occurred at 11C̊, 80 umol photons m⁻² s⁻¹ and 30ppt salinity. Porphyra torta (Pt) grew best (6.5%d⁻¹) at 15C̊, 80 umol photons m⁻² s⁻¹ and 30ppt. Porphyra pseudolinearis (Pi) generally had higher growth rates with optimal growth (8.8% d⁻¹) occurring at 7C̊, 160 umol photons m⁻² s⁻¹ and 30ppt. Salinities between 20 and 40ppt and irradiances between 20 and 40ppt and irradiances between 20 and 160 umol photons m⁻² s⁻¹ generally had little effect on growth rates, but there was virtually no growth at <10ppt. Plant hormones were shown to promote the growth of conchosporangia, which increased by 6.9-31.7% (for Pa), 4.7-25.7% for (Pe, P. pseudolanceolata) and 8.9-35.1% for (Pi). Concentrations between 0.4-1.6ppm of kinetin and indole-3-acetic acid at higher temperatures generally had higher stimulatory effects, but Pe had higher volume increase at lower temperatures. Irradiance, temperature and salinity influenced photosynthesis of the conchocelis. P-I curves, Pmax, Imax, and Ic varied with temperature and species. Higher photosynthesis generally occurred at 25-35ppt salinities. Pa had maximal photosynthesis at 11C̊ and 60 umol photons m⁻² s⁻¹, whereas Pi and Pt had maximal photosynthesis at higher temperatures and irradiances. The highest photosynthesis (240 umol O₂ production g dw⁻¹ h⁻¹) of Pa occurred at 11C̊, 60umol photons m⁻² s⁻¹ and 30ppt. Pi and Pt had optimal photosynthetic rates (200 and 210, respectively) at 15C̊, 120 umol photons m⁻2 s⁻¹ and 30ppt. Conchocelis had lower respiration rates (30-35) at 7C̊ than at 11 and 15C̊ (45-58 umol O₂ consumption g dw⁻¹ h⁻¹). All three species exhibited lowest respiration at salinities between 25-35ppt. Phycoerythrin (PE), phycocyanin (PC), carotenoid Ca) and chlorophyll a (Chl.a) contents were significantly affected by irradiance, nutrient concentration and culture duration. For Pa, Pi and Pt, maximal PE (63.2-95.1 mg/g.dw) and PC content (28.8-64.8 mg/g.dw) generally occurred at 10 umol photons m⁻² s⁻¹, f/4-f/2 nutrient concentration after 10-20 days, while Pe had highest PE (73.3 mg/g.dw) and PC content (70.2 mg/g.dw) at 10 umol photons m⁻² s⁻¹, f nutrient concentration after 60 days. For all four species, highest Ca (3.4 - 6.3) and Chl.a content (3.6 - 8.1 mg/g.dw) generally occurred at 0-10 umol photons m⁻² s⁻¹, f/4-f nutrient concentration. High irradiances, low nutrients and longer culture duration generally caused a decline of pigment content.
    • Physiological ecology of the arctic ground squirrel: Energy metabolism, torpor, and behavioral endocrinology

      Buck, Charles Loren (1998)
      I monitored seasonal changes in body condition and dates of immergence into and emergence from hibernation in a natural population of arctic ground squirrels (Sphermophilus parryii kennicottii) living on the North Slope of Alaska. Age and sex differences in changes of body condition and hibernation chronology are attributable to sex differences in energetic costs associated with preparation for reproduction and differences in reproductive status within males. While winters are long and environmental conditions faced by arctic ground squirrels in northern Alaska are extreme, the timing of hibernation did not differ appreciably from patterns observed in Sciurid populations living in temperate latitudes. To determine the environmental conditions faced by S. parryii during hibernation and to investigate the effect of overwinter temperature on change in body condition of the individual, I instrumented 18 burrow sites with temperature-sensitive data loggers to record soil temperature at hibernacula depth. Burrow sites did not differ significantly in soil temperature over years, but significant thermal differences were observed among burrows. Burrows with more shrubby vegetation accumulated deeper snow and had higher overwinter temperatures than did windswept sites. Females hibernated at warmer sites than did males and adults hibernated at warmer sites than juveniles. Repeated measures of overwinter changes in body condition were not significantly correlated with winter soil temperatures for any age or sex class. To determine the energetic cost associated with hibernation under arctic conditions, I measured metabolic rate, respiratory quotient, and body temperature of arctic ground squirrels in steady-state torpor. At ambient temperatures below 0$\sp\circ$C, body temperature remained constant and metabolic rate increased proportional to the gradient between body and ambient temperatures. With increased metabolic rate associated with decreased ambient temperature, animals switched from catabolism of exclusively lipid fuel to mixed fuels. To test the effects of male-male aggressive behavior on circulating testosterone and corticosterone concentrations during the breeding season, I staged encounters between free-living males and sampled them for blood following the interaction. Levels of testosterone and corticosterone significantly increased following the encounter compared to in control animals, and the magnitude of increase significantly correlated with the intensity of the interaction.
    • Physiological effects of the parasite ichthyophonus on spawning chinook salmon and their offspring in a Yukon River tributary

      Floyd-Rump, Theresa; Horstmann-Dehn, Larissa; Skaugstad, Calvin; Atkinson, Shannon; Sutton, Trent (2015-12)
      In recent years, Chinook salmon Oncorhynchus tshawytscha returns to the Yukon River, Alaska, have been substantially reduced. In summer 2010-2012, spawning Chinook salmon (n=51, 32, and 23, respectively) were collected from the Salcha River, a tributary of the Yukon River, to determine the effects of Ichthyophonus, a protozoan parasite, on salmon reproductive success. Eggs and milt from Ichthyophonus-infected and non-infected parents were collected in 2010 and cross-fertilized to investigate offspring survival and potential second-generation effects induced by the parasite. Proximate composition analysis of adult muscle, eggs, and alevins, and blood chemistry analysis of adult blood plasma and alevin whole body homogenates were analyzed to explore potential differences between Ichthyophonus-infected and non-infected salmon. Ichthyophonus infection prevalence was 7.8, 6.3, and 8.3 % in 2010, 2011, and 2012, respectively. Egg lipid content was significantly higher in eggs from Ichthyophonus-infected females, compared to eggs from Ichthyophonus-negative females. Survival of fertilized eggs to hatching was not significantly different between offspring from Ichthyophonus-infected parents (Mean±1SD: 24.4±29.8 % survival) and non-infected parents (41.0±24.8 % survival). Proximate composition (% lipid, % protein, kJ/g) of muscle from spawning adult salmon also did not differ, nor did total body composition or morphology of alevins produced by either Ichthyophonus-infected or non-infected parents. We found no significant differences in blood plasma cortisol concentrations (a stress indicator) between Ichthyophonus-positive and negative adults or their offspring. There were also no significant differences in blood chemistry parameters indicative of tissue damage between Ichthyophonus-positive and Ichthyophonus-negative adults or resulting alevins, with the exception of aspartate aminotransferase, which was unexpectedly higher in plasma of Ichthyophonus-negative adults. Overall, infection with Ichthyophonus does not appear to impact the spawning ability or spawning success of Chinook salmon in the Salcha River.
    • Physiology of the endocrine, cardiorespiratory and nervous systems in pinnipeds: Integrative approach and biomedical considerations

      Zenteno-Savin, Tania; Castellini, Michael A. (1997)
      This thesis explored several aspects of the hormonal and cardiovascular physiology in pinnipeds (seals and sea lions). Plasma concentrations of the vasoactive hormones angiotensin II (Ang II), arginine vasopressin (AVP, the antidiuretic hormone) and atrial natriuretic peptide (ANP) were studied in six species of seals and sea lions. Resting levels of AVP, ANP and Ang II in these pinnipeds were similar to those reported for other vertebrate species, including humans. Age-related differences were found in the concentrations of these hormones in seals and sea lions. Geographic differences in hormone concentrations were found in Steller sea lions and harbor seals. To address the endocrine and cardiovascular responses to breath-holding (apnea) in marine mammals, heart rates and plasma levels of Ang II, AVP and ANP were studied in Weddell seal (Leptonychotes weddellii) and northern elephant seal (Mirounga angustirostris) pups during periods of spontaneous breathing (eupnea) and apnea. Ang II, AVP, and ANP, as well as the autonomic nervous system, were found to contribute differently to the control of heart rate in seal pups, depending whether the respiratory system was in eupnea or apnea. Because of changes in seals of different ages, it appeared that the integration of cardiorespiratory and hormonal function is not fully mature at birth, but develops post-natally, probably simultaneously to the development of diving behavior. These studies also suggested that the factors affecting cardiorespiratory function, including hormones, may differ by species. Plasma concentrations of AVP, ANP and Ang II were measured during food limitation and fasting in captive Steller sea lions (Eumetopias jubatus) and compared to levels in free-ranging conspecifics. The results suggest that Steller sea lions have a remarkable capacity to maintain hydrosmotic and endocrine balance during short-term food limitation and fasting. Hormonal studies did not provide conclusive evidence that Steller sea lions in Alaskan waters are currently affected by long-term food limitation.
    • Phytochemical comparison of Puccinellia arctica to Poa pratensis, Puccinellia langeana, and Puccinellia phryganodes for evidence of chemical defense

      Volz, Trent Joseph (2000-05)
      Puccinellia arctica is a species of arctic grass that is unpalatable to Canada geese, Branta canadensis, and may be an effective and non-lethal means of controlling the growing populations of urban Canada geese that are problematic in many areas of North America. The secondary metabolite profile of P. arctica was compared to the metabolite profiles of three palatable grass species to determine the plausibility that P. arctica is chemically defended. The volatile and non-volatile secondary metabolite profiles of both P. arctica and the palatable grasses were the same. No alkoloids were detected in any of the grasses. Condensed tannin levels were similar in all of the grasses. Gallotannin levels were higher in the palatable grasses than in P. arctica. However, ellagitannin levels were higher in P. arctica than in the palatable grasses and may be responsible for its unpalatability to Canada geese.
    • Phytochemical investigation of Colophospermum mopane

      Reiter, Emily; Clausen, Thomas; Green, Thomas; Reichardt, Paul (2002-05)
      A previously partially-characterized diterpene alcohol was isolated from Colophospermum mopane, and its structure completely elucidated. A second novel diterpene alcohol, structurally related to the first, was also fully characterized by NMR spectroscopy. A proposed precursor of the diterpenes, a mixed pair of diterpene aldehydes, was isolated, and upon reduction yielded a mixture of both diterpene alcohols. These diterpenes represent important 'missing' links in the biogenesis of 9,13-epoxylabdanes. Seeds of C. mopane were grown in greenhouse conditions to determine when these diterpenes were produced. Two sesquiterpenes and two diterpenes were quantified by GC-MS. Seedlings grown from seeds rinsed in hexane grew faster and produced terpenoids sooner than the control group. It is likely that C. mopane seeds have terpenoids present in concentrations high enough to minimize competition from herbaceous perennials, at the cost of some degree of auto-toxicity, so rinsing promotes growth and terpenoid production.
    • Phytochemistry and chemosystematics of Artemisia arctica in Alaska

      Riggins, Chance W.; Clausen, Thomas; Stoltzberg, Richard; Schwaegerle, Kent (2001-05)
      Artemisia L. (Asteraceae - Anthemideae) is a large and taxonomically complex genus occurring widely throughout the northern hemisphere. Chemical investigations in this genus have mainly been stimulated by the economic and/or medicinal importance of many of its members. This chemical knowledge has also provided useful criteria for resolving systematic uncertainties within the genus. Alaskan Artemisia species are little known chemically despite their historic and contemporary medicinal use. Therefore, an investigation of the chemistry of Alaskan Artemisia arctica was initiated with the dual purpose of searching for structurally novel and/or biologically active compounds and contributing additional criteria for systematic studies of this taxon. Collections of A. arctica from four different geographic locations in Alaska were analyzed for chemical characters and biological activity. The roots and leaves afforded one novel acetylenic isocoumarin, in addition to several known acetylenic and non-acetylenic compounds. The biological and systematic significance of these results are discussed.
    • Phytoremediation strategies for recalcitrant chlorinated organics

      Schnabel, William Edwin; White, Daniel (2000)
      The purpose of the research was to investigate novel strategies for the phytoremediation of recalcitrant chlorinated organic soil contaminants. The recalcitrance of many chlorinated organics is related to chemical stability and bioavailability. Mycorrhizal fungi have the potential to enhance the degradation of such compounds through the action of lignolytic enzyme systems, and to increase the bioavailability of such compounds through increased root surface area and reach. Furthermore, the addition of surfactants has the potential to increase compound bioavailability via increased solubility. The organochlorine pesticide aldrin, and the polychlorinated biphenyl 3,3'4,4 '-tetrachlorobiphenyl (TCB) were chosen as representative recalcitrant contaminants. Feltleaf willow (Salix alaxensis) and balsain poplar (Populus balsamifera) were chosen as vegetative species likely to be useful for phytoremediation in sub-arctic ecosystems. Mixed-culture mycorrhizal fungi were first shown to be capable of taking up the hydrophobic contaminants in vitro. In the same experiments, surfactant addition increased the level of contaminant uptake. In subsequent vegetative uptake studies, mycorrhizal infection was highly correlated with the uptake of aldrin and TCB in the willow systems. In the poplar systems, this correlation was not as strong. Once taken up into the vegetative matrix of either species, most of the carbon originating from the chlorinated compounds existed as bound transformation products. Additionally, water-soluble transformation products of aldrin were formed in all of the soils tested, and such transformations were enhanced in the presence of vegetation. TCB transformation products were not detected in any of the soils tested. Surfactant addition did not impact the fate of either contaminant in the vegetative uptake studies. The surfactants, in the concentrations added, did not sufficiently solubilize the contaminants into the soil solution. The results of these studies indicated that the phytoremediation of recalcitrant chlorinated organics such as aldrin and TCB could be enhanced through the action of mycorrhizal fungi, and that surfactant addition has the potential to increase mycorrhizal uptake. Field studies were recommended, involving the use of specific degradative fungal species and effective surfactants.
    • Pilot studies of the genetics of obesity in the western Alaska Native population

      Harrington, Erik Briggs (2004-05)
      Obesity in Alaska Natives is increasing, posing significant health risk for the development of associated diseases. This study examined candidate obesity genes in a set of anonymized Alaska Native DNA samples for loci that might predict obesity risk. DNA samples were divided into three groups according to body mass index: lean (BMI <̲23), in-between (23<BMI <30), and obese (BMI>̲ 30). Screening of 5,043 base pairs from the exons of leptin (LEP), leptin receptor (LEPR), neuropeptide-y (NPY), and melanocortin-4-receptor (MC4R) yielded previously discovered SNPs in NPY and LEPR. Additionally, two known promoter region SNPs in NPY and Uncoupling Protein-2 (UCP2) were analyzed. SNPs were in Hardy Weinberg equilibrium, showed little genetic variation between populations, and were not associated with BMI category. We concluded that the study lacked power to detect an association due to an inability to correct for variables known to affect BMI and a small sample size. However, this study enabled pilot studies of several SNP genotyping platforms and the evaluation of allele frequencies in the Alaska Native population, illuminating the value of known SNP genotyping vs. SNP discovery and the benefit of a direct association study vs. an indirect association study.
    • Pit-fired in St. Michael

      Lease, Tracy René (2003-12)
      'Pit-Fired in St. Michael' is a collection of essays exploring human landscapes inside the geography of place. Reflecting on the influences family, instinct, language, memory, community and nature have on the narrator, the essays move from the west coast of Alaska to the interior White Mountains, from hospital nurseries and grocery store lines to remote dog-sled trails and cabins. Essays about raising a child sit beside pieces that journey back through the narrator's early experiences in Alaska, college years in Oregon and childhood in the deserts and suburbs of Utah. These essays range in style from tight-knit anecdote to memoir to idea-based explorations. Utilizing story-telling techniques, dialogue, section breaks, and over-arching metaphor, these pieces borrow strategies from both fiction and poetry. Though the essays are diverse in both content and technique, they all center on the narrator's attempts to better understand self inside human and natural worlds.
    • Pitch and voice quality: acoustic evidence for tone in lower Koyukon

      Alden, McKinley R.; Tuttle, Siri; Cooper, Burns; Shoaps, Robin (2019-05)
      This thesis addresses the acoustic realization of tone in the Lower dialect of the Koyukon language. The Lower dialect is the only one of the three Koyukon dialects attested to have tone. Its exact nature, however, remains unclear. This study seeks to corroborate previous attestations of low tone in Lower Koyukon by providing acoustic evidence of its realization. Therefore, there are three primary objectives: a) to determine how tone is produced in Lower Koyukon with respect to pitch; b) to examine any interactions between tone and potential pitch-altering phenomena; and c) to determine the realization of creaky phonation during tone production, if such exists. All of the data for this study was gathered from a single consultant, a fluent Lower Koyukon speaker. Three elicitation strategies were employed. First, a game of bingo was developed from a list of words predicted to carry a tonal syllable. Second, the consultant was asked to teach the researcher how to pronounce a series of short phrases and sentences that contained a word with a tonal syllable. Finally, the researcher selected a story written in Koyukon for the consultant to read aloud. During the analytical process, each word predicted to carry tone was compared to both a control set of non-tonal words and a set of words that may or may not carry tone. The only statistically significant difference was that the set of tokens predicted to carry tone had higher measures of creak than the control set. As creaky voice is inherently linked to tone production, this finding supports previous attestations of tone. However, both quantitative and qualitative methods were employed for this study, and several examples are cited which show both that there is a significant pitch change on syllables predicted to carry tone. Moreover, it appears that that this pitch rises. The implications of this study are therefore that tone is present in modern Lower Koyukon, and that this tone may by high, rather than low, as has been previously claimed.
    • Pitorifices and small pumps in cold region water distribution systems

      Mauser, Michael William; Zarling, John; Carlson, Robert; Kane, Douglas; Goering, Douglas (1995)
      Most buried potable water distribution systems in colder regions of Alaska rely on pitorifices to provide circulation between the water main and service connections for freeze protection. Pitorifices are scoops which project into the main. When water is circulated in the main, they create a differential head which induces flow through dual service lines. Pitorifices have provided an inexpensive and simple alternative to installing a small pump at each service to provide circulation. However, very little information was available on the hydraulic performance of these devices. The objectives of this study were to: (i) develop techniques to measure pitorifice performance in the field; (ii) characterize performance of commonly used pitorifice shapes with different insertion depths and relative sizes in full-scale testing; (iii) develop an improved shape; (iv) research the competing technology of small pumps; and (v) present the information in a way that is useful to engineers. An inexpensive device for field checks of both differential head and flow rates at service lines was developed and the use of a low head loss meter was initiated. Methods and results of field studies in four different water systems are presented. Five commonly used pitorifice shapes and four new shapes were evaluated. The best shape was found to be one of the existing shapes, which is also one of the easiest to produce but not the most popular. It was also determined using a larger service line size can be cost effective. Test results are graphed and a theoretical framework is provided for designers. Smaller, energy efficient pumps may provide a cost effective alternative to pitorifices in some situations. Requirements for small pumps used for circulation in place of or to supplement pitorifices are given. Performance test results for different pumps are presented, most of which have not been used previously for service line circulation. Pumps with significantly lower operating costs than those in current use are identified. Several of these pumps were installed in services for long term testing.
    • A place for the birds: the legacy of Creamer's Field Migratory Waterfowl Refuge

      Ryan, Jessica A. (2003-12)
      This thesis details the farming history and current importance of the Creamer's Field Migratory Waterfowl Refuge in Fairbanks, Alaska. More significantly, it is the story of a grassroots effort by the community of Fairbanks, working with a kindly old farmer, to preserve open land in the heart of a rapidly expanding city for the benefit of the thousands of migrating cranes, geese and ducks that rely upon the grain fields each spring and fall. Because of their vision, Creamer's Field has become a center for environmental education, outdoor recreation, and biological research while actively providing for the needs of wildlife.