Now showing items 1342-1361 of 3321

• #### Harmothoe imbricata: species complex or complex species?

Accurate estimates of species diversity are constrained by cryptic species complexes, in which multiple closely related species are grouped under a single species name due to the absence of clear morphological differences. Cryptic diversity is known to be prevalent in polychaete worms, a mostly marine group commonly known as bristle worms. A recent survey of polychaete diversity discovered that the widespread scale-worm Harmothoe imbricata comprises multiple distinct mitochondrial lineages based on analysis of the Cytochrome c oxidase I (COI) gene, which is often referred to as the 'barcoding' gene. Analyses based solely on DNA sequences from COI may overestimate the number of lineages comprising a cryptic species complex, so it has been recommended that cryptic species investigations incorporate nuclear gene sequences. The goal of this study was to determine whether the incorporation of DNA sequences from the nuclear genome corroborates the designation of H. imbricata as a cryptic species complex. I sequenced segments of COI and five nuclear genes: ITS1, ITS2, H3, and portions of the 18S and 28S genes of H. imbricata and analyzed them using distance measures, maximum likelihood, and Bayesian inference. I compared phylogenetic trees produced from mitochondrial and nuclear DNA sequences, as well as from a combined mitochondrial/nuclear dataset. Harmothoe imbricata was found to include five mitochondrial lineages, whereas the nuclear sequences only supported four well-defined lineages. These results corroborate previous reports showing COIbased cryptic species investigations find more lineages than nuclear DNA based investigations. These results provide additional lines of evidence that H. imbricata is a cryptic species complex. These divergent lineages likely arose after being separated during the last glacial maximum but they are now found in sympatry. A thorough morphological study of H. imbricata populations may reveal phenotypic differences correlated with the genetic lineages identified here.
• #### Headwater stream invertebrate communities: a comparison across ecoregions and logging histories

Monitoring stream condition is not always conducted with understanding how climate may influence anthropogenic disturbances. Stream monitoring has traditionally been accomplished through sampling benthic invertebrates, while sampling drifting invertebrates as a potential monitoring tool has received little attention, in spite of drift often being easier and less expensive to sample. The objectives of this study were to understand how logging influences headwater stream invertebrate communities (benthic and drift) across two ecoregions in the Cascade Range, central Washington, and to determine whether drift samples might serve as a replacement for benthic samples in assessing headwater stream condition. Benthic and drifting invertebrates were sampled from 24 headwater streams in logged and unlogged watersheds within two ecoregions (wet and dry), and community metrics contrasted. Invertebrate community responses to logging varied with ecoregion (e.g., higher shredder densities in logged watersheds of wet ecoregion only). Differences in benthic community structure were not reflected in the drift, and relationships between benthos and drift were highly variable. Although both sampling types (benthic, drift) revealed ecoregional and land-use (logging) differences in invertebrate communities, lack of consistent relationships between the sampling types suggests drift sampling does not provide more reliable information about stream benthos or headwater stream condition.
• #### Healing from within: the wellness team concept

This project was created to chronicle one community's effort to stem the tide of alcohol abuse and address issues of trauma that had plagued the community for many years despite services provided by the State. It is the story of a group of people who came together despite differences to form a team of service providers that would begin a journey of healing for themselves and the community. The results are coming slowly, but indicate less drinking, less tolerance for any form of abuse, and a healthier lifestyle. Although the journey has not ended, there are many more indicators showing that the community is taking responsibility for their problems. The team members as well choose a healthier lifestyle maintaining sobriety, eating healthier, and exercising regularly.
• #### Health and condition of juvenile chinook and chum salmon near the Chena River Dam, Alaska

During May-June, 1995 and 1996, outmigrating chum salmon, Oncorhynchus keta, and chinook salmon, O. tschawytscha, were captured in the Chena River near the Chena River Lakes Flood Control Project. Fish condition was determined through the investigation of physical injury and scale loss. Except for one sample, the proportion of injured fish was never greater than 7% for chum or chinook salmon. Few injuries were severe. The proportion of chinook salmon with scale loss ranged from 1-33%, most of which were only partially descaled. When significant length differences existed, injured, descaled, and partially descaled fish were always larger than non-injured and non-descaled fish. Arctic grayling (Thymallus arcticus) diet by weight consisted of chum salmon (2%), invertebrates (89%), other fish (3%), and miscellaneous material (6%). Plasma cortisol levels were used as an indicator of the primary stress response of chinook salmon and did not indicate any unusual physiological stress level.
• #### Health And Empires: Implications For Political Development On The Health Of The Inhabitants Of Great Moravia (9Th--10Th Centuries)

The early medieval period was a time of great change in Europe. Politically thee empires ruled Europe: Charlemagne's Carolingian Empire, the Holy Roman Empire and the Byzantine Empire. During this time early cities began to form in Europe, and new patterns of settlement developed. Great Moravia was a state level society in the southeastern region of the Czech Republic during the late 9th and early 10th centuries. This thesis explores the impact of urban development on the health of its inhabitants. In order to do this, rural (Josefov and Lahovice) and urban (Mikulcice-Kostelisko) skeletal populations were examined for cribra orbitalia, porotic hyperostosis, and linear enamel hypoplasia (LEH). Cribra orbitalia had a consistently low frequency in all populations. This suggests that anemia (often due to chronic parasitic infection and subsequent malnutrition) was present, but at a low level. LEH frequency was significantly higher, with more age of occurrence variation in the urban population. The results of this thesis suggest that despite the advantages of greater wealth and access to greater amount of food (and food varieties) urban populations were under more stress than rural populations. These results have implications about the impact of urban development and migration in modern developing nations.
• #### Health Assessment In The Bowhead Whale

Tissue samples and morphometric data were collected from 64 bowhead whales landed during the 1998-2002 subsistence hunts in Barrow and Kaktovik, Alaska. Our primary goal was to assess the health status of the Bering-Chukchi-Beaufort Seas stock of bowhead whales. Ages of whales were determined via aspartic acid racemization of the eye lens nucleus, baleen stable carbon isotope analysis and morphometric and histologic indices. We investigated the gross and microscopic anatomy of organs and blubber, thyroid hormone concentrations, serum haptoglobin, vitamin A and E concentrations in liver, blubber and serum and essential element concentrations in liver and kidney. Thyroid hormone and vitamin A were also evaluated as potential biomarkers of organochlorine (OC) concentrations in blubber, liver and serum. Neither of these substances was found to correlate with the relatively low OC concentrations found in these mysticetes. Histological changes of interest included renal interstitial fibrosis, hepatic periportal fibrosis/pigmentation/lipidosis, splenic extramedullary hematopoiesis and pulmonary fibromuscular hyperplasia. Changes in the kidney and lung were related to both age and renal and hepatic Cd concentrations. Most of the histological differences observed did not appear to adversely affect organ function or health of the individual. Thyroid hormone concentrations were stable over age/sex/seasonal groups, however, pregnant females had significantly lower total and free thyroxine than non-pregnant adult females and other age-sex classes. Serum haptoglobin was measured as an indirect determinant of acute inflammation, with three reactors found among 51 whales examined. Liver contained the highest mean concentrations of vitamins A and E (followed by epidermis, blubber, and serum and serum, epidermis, and blubber, in order). Finally, blubber percent collagen was measured at 30 locations on each whale and was found to be stable by site and most depths, with the most internal region of the reticular dermis being the only exception. Overall, the bowhead whales were healthy. However, climate change, offshore development and increases in arctic pollution emphasize the importance of baseline data collection. An ongoing surveillance effort is recommended to ensure that the species will be viable for generations to come and to assure subsistence users of the robust and healthy status of this stock of whales.
• #### Health in predynastic Egypt: using skeletal stress indicators to assess the overall health of a working class population in hierakonpolis

The present project attempts to assess the overall health of a Predynastic Egyptian working class population, based on skeletal stress indicators. This study contributes to a growing knowledge base regarding the biological anthropology of Predynastic Egyptians. Information generated from this research may help address larger questions, such as: how do Predynastic Egyptian mortality profiles compare with each other, and with other groups from around the world? Fifty-three skeletons were examined from Hierakonpolis' HK43 cemetery. Data were collected according to conventional osteological methods. Most skeletal stress indicators observed were mild. Evidence of degenerative disease in adults reflected lifetimes of hard, physical labor. The presence of dental caries, calculus deposits and hemopoietic lesions suggested a grain-dependant diet. Interestingly, the majority of these people appeared to be young or middle-aged adults in good health. Whatever caused their deaths is not immediately apparent from their skeletal remains.
• #### Heat And Freshwater Controlling Processes On The Northern Gulf Of Alaska Shelf

We examined conditions and processes that control the distribution of heat and freshwater on the northern Gulf of Alaska (GOA) shelf. Cross-shelf heat gradients are weak throughout the year, while salinity gradients are substantial due to the impact of coastal freshwater runoff. Outer shelf water properties are influenced by large anticyclonic eddies, while the inner and middle shelves may be regulated by wind and freshwater runoff dynamics around the Alaska Coastal Current (ACC). On the outer shelf, anticyclonic eddies propagate from the eastern GOA southwestward along the continental slope, where they favor on-shelf (off-shelf) transport of saline and nutrient-rich (fresh and iron-rich) waters Certain along-shelf locations are identified where low-salinity coastal waters are found near the shelfbreak within reach of eddies and may be regions of enhanced cross-shelf freshwater transport. The eddies have lifetimes of ~5 years and increase in size and sea level anomaly west of the Seward Line, which implies more vigorous eddy cross-shelf exchange in the northwestern GOA. By comparison, on the inner shelf the heat and freshwater distribution is dominated by large coastal river runoff, which forces the ACC and controls the vertical distribution of temperatures through stratification. In May 2007, the coastal GOA revealed some of the lowest ocean temperatures since the early 1970s, initiated by strong atmospheric cooling and reduced coastal runoff in November 2006. Stepwise regression shows that 81% of the variability of deep temperatures is explained by salinity stratification and air-sea heat fluxes. Weak baroclinic flow in May 2007 likely aided the cooling through reduced along-shore heat transport. A more detailed examination of heat transport indicated that along-shore heat flux convergence in the ACC may re-supply 10-35% of the heat removed by air-sea fluxes throughout the coastal GOA cooling season, while the annual mean cross-shore heat flux convergence is insignificant. Spatial gradients show increasing heat fluxes from off- to on-shore and from east to west. The cross-shore gradients result from wind speed gradients due to ageostrophic near-shore wind jets near coastal mountains, while the along-shore gradients result from larger-scale pressure systems. While the ACC advects coastal freshwater around the GOA shelf its waters are subjected to disproportional heat loss west of the Seward Line.
• #### Heat Increment And Methane Production By Muskoxen Fed Browse

Many browse species contain anti-herbivory compounds that deter consumers by their toxicity or digestive inhibitory effects. Animals that consume browse are assumed to pay a detoxification energy cost, which increases the heat increment of feeding (HIF). Ruminants also lose potentially metabolizable energy as methane (CH4); but browse may lower CH4 production. I hypothesized that increases in energy loss to HIF by animals eating browse could be offset by a reduction in energy lost via CH4 production. Muskoxen eat both graminoids and browse and are considered to be energetically conservative due to their existence in a sparse arctic environment. These traits make them ideal for energetic studies. Muskoxen were fasted for 24 h and then fed a test meal composed of hay mixed with graded percentages of one of three browse species (Willow: S. alaxensis, S. pulchra, birch: Betula nana). Browse consisted of twigs in winter and leaves in the summer. Heat increment of feeding and CH4 production were estimated with an indirect calorimeter. Muskoxen had a 33% lower metabolic rate in winter in comparison to summer. The main increase in EE from winter to summer occurred between April and May, and the summer to winter decrease between August and September. Addition of woody twigs or leaves of birch to hay diets tended to depress HIF following the test meal. Woody twigs and leaves of willow added to hay diets tended to increase HIF. Woody browse tended to lower CH4 production when fed at >20% of the meal. Leafy browse had variable effects on CH4 production; S. alaxensis was stimulatory, S. pulchra was inhibitory, while B. nana showed not consistent pattern. Generally, CH 4 production by muskoxen was low at 2.0--3.2% of GE intake when compared with estimates for sheep and cattle (2--12% of GE intake). Although diets high in fermentable carbohydrates stimulated methane production, secondary compounds apparently had a suppressing effect as deduced from the relation of in vitro digestibility to methane production. Given the low overall CH4 production in muskoxen, and the inconsistency of the relationship of CH4 to HIF, it is unlikely that significant gains in energy retention are made by reductions in CH4 production through browse consumption.
• #### Heavy metal tissue distributions in southwestern Alaskan waterfowl: total mercury assays from muscle, brain, and bone

Food containing mercury has been identified as a possible health risk. Total mercury (THg), which is inorganic (Hg²), and methylmercury (MeHg) species, has been found in the arctic food web. In Alaska, birds are an important seasonal component of the diet, but have not been studied extensively and characterized for the presence of mercury. Birds are good subjects for examination because they feed at different trophic levels, can be long-lived, and are both abundant and widely distributed. Not only can birds monitor local Alaskan food webs, but, if they are migratory, can be used to compare exposure in different regions. Mercury levels in muscle, brain, and bone tissue of 140 birds taken by subsistence hunters across southwestern Alaska were determined. I tested the null hypothesis of no interspecific differences in total mercury levels in the 18 species of Alaska birds surveyed. There were interspecific differences with the Lesser Scaup (Aythyra marila mariloides), and the Black Scoter (Melanita nigra Americana), having the highest levels of mercury. In general, mercury levels were higher in muscle than in brain or bone. The mean values for mercury in the species studied were lower than the levels known to cause adverse reproductive or behavioral effects.
• #### Heavy metals in the sediments of an arctic lagoon, northern Alaska

The total abundances of V, Cr, Mn, Fe, Co, Ni, Cu, and Zn in oxic, nearshore sediments of north arctic Alaska, are similar to those of corresponding pristine or pre-industrial-age sediments of many tropical-temperate regions, and thus do not reflect the unique weathering and depositional processes of the Arctic. Laboratory experiments on metal partitioning suggest that about 50% of the metal contents (<20% for V, Cr), which are bound predominantly in Fe oxides, may be mobilized into solution following the onset of reducing conditions at the sediment surface. A three-part extraction design would be effective in discriminating the three major associations of heavy metals in the sediments: easily leachable, Fe hydroxides, and refractory particles, and is recommended for use in monitoring the nearshore Beaufort Sea for future contamination by heavy metals.
• #### Helping veterans through outreach

The present Master's project seeks to develop a better understanding of Veterans and what they are going through. Research methods include extensive data on the high suicide rates of Veterans. Veteran and service members are in need of a service to them that will address the issue of suicide and what can be done to help and eliminate this problem. The programs that need to be designed to help needs should be in locations that have Veteran populations so as to serve them with their needs. Ultimately, Veterans Affairs (VA) officials have boosted their mental health personnel and suicide hotline staff in recent years, but at this time their data does not reflect it helping Veterans getting the help that they so desperately need.
• #### Hemocyte and tissue changes by crude oil in the blue mussel Mytilus edulis

This study examines the effects of Prudhoe Bay crude oil on the number and types of circulating hemocytes, on the phagocytic response, on spawning progression, and on internal structural changes. The number of hemocytes was reduced with 4-5 week exposure to 1000 nL/L of oil; a significant number of individuals showed a higher than average cell count with longer exposure. An increase in agranulocytes in the 8-9 week control population does not occur in populations exposed to 1000 nL/L and 500 nL/L of oil for 8-9 weeks, but, the phagocytic response was significantly depressed. The Chi-square test showed that oil interferes significantly with progression of spawning. Analysis of internal tissue structure indicates that oil can affect adipogranular storage cells, vesicular tissue, and digestive tubule cells. The changes occurring in circulating hemocytes are not necessarily consistent with changes in internal morphology.
• #### Hepatitis B in Arctic ground squirrels (Spermophylus parryi): epidemiology and population biology

Using a mark-recapture design, an epidemiological investigation of Hepatitis B was performed on four colonies of Spermophylus parryi. Animals were trapped, marked and bled. Serum samples were screened for Hepatitis B markers. Program MARK was used to estimate survival rates. Prevalence rates ranged over 55% and 1999 rates were 10% higher than 1998. Vertical transmission of the virus was not observed and juveniles were unaffected by the mother's hepatitis status. Immigrants had lower prevalence rates than residents and incidence rates accelerated throughout the study. Survival was highest during the over-winter period and adult rates were lower in 1999. Recovered animals had different survival rates than other animals and survival rates of recovered animals were lower in 1999. Evidence suggests that delayed development of disease and/or environmental conditions lowered survival rates of recovered adults in 1999. Techniques that integrated epidemiology and population biology proved fruitful and worthy of further development.
• #### Herbivore-mediated effects on ecosystem processes in a near-Arctic salt marsh

Herbivores influence, and often regulate energy flow. I investigated interactions between herbivory and the foods on which geese rely while nesting and rearing their broods on the Yukon-Kuskokwim Delta in southwestern Alaska. In a captive Cackling Canada gosling (Branta Canadensis minima) experiment I decoupled the effects of seasonal declines in forage quality and availability on gosling development. An 11% decline in forage quality translated to goslings that were structurally smaller and 100 g lighter at 31 days of age. Forage availability had similar effects on gosling size, and the combined magnitude of these effects are similar to those observed in wild populations. I manipulated within-season grazing history of 'Carex subspathacea' swards within brood-rearing areas used by Black Brant geese (Branta bernicla nigricans). Spatial variation in forage quality and availability exceeded seasonal variation. Brant consumed over 95% of the annual aboveground production of these swards without any short- or apparent long-term effects on aboveground growth. Adding grazing pressure to 'C. ramenskii, ' or removing grazing pressure from 'C. subspathacea, ' resulted in a bi-directional shift in the morphology and nutritional characteristics of these sedges. The areal extent of 'C. subspathacea' increased 2 to 8% of the Tutakoke landscape with a concomitant decrease in 'C. ramenskii' meadows between 1991-1998. Brant have been increasing the carrying capacity of the Tutakoke River colony following a population decline in the early 1980's. The population has increased beginning in 1988, yet remains below historic numbers. Density-dependent effects on gosling growth accompanied the population increase initially. However, gosling mass has increased over the past decade due to herbivore-mediated increases in the areal extent of grazing lawns.
• #### Heterogeneity and bias in abundance estimates of outmigrating chinook salmon in the Chena River, Alaska

The objective was to examine bias due to heterogeneity in capture probability (p) in an abundance estimate for chinook salmon (Oncorhynchus tschawytscha) outmigrants in the Chena River, Alaska. A higher proportion of day-marked fish (21 / 636 = 0.0330) compared to night-marked fish (17 / 1724 = 0.0098; p<0.0001, α=0.05) was recaptured at the lower site in a Cormack-Jolly-Seber experiment with upper, middle and lower sites. Heterogeneity was also likely at the middle site between upper site-marked and unmarked fish. Simulations with heterogeneity confined to the middle and lower sites (i.e., due to inadequate mixing) caused small bias (<2.5%) in the upper site abundance estimate. With heterogeneity at all three sites (a subpopulation effect), the upper site estimate had 22.9% to 29.3% negative bias. Because heterogeneity observed in the Chena was probably due to inadequate mixing (related to daytime trap evasion), bias in the upper site estimate was probably small.
• #### Heterogeneity And Bias In Abundance Estimates Of Outmigrating Chinook Salmon In The Chena River, Alaska

The objective was to examine bias due to heterogeneity in capture probability (p) in an abundance estimate for chinook salmon (Oncorhynchus tschawytscha) outmigrants in the Chena River, Alaska. A higher proportion of day-marked fish (21/636 = 0.0330) compared to night-marked fish (17/1724 = 0.0098; p $<$ 0.0001, $\alpha$ = 0.05) was recaptured at the lower site in a Cormack-Jolly-Seber experiment with upper, middle and lower sites. Heterogeneity was also likely at the middle site between upper site-marked and unmarked fish. Simulations with heterogeneity confined to the middle and lower sites (i.e., due to inadequate mixing) caused small bias ($<$2.5%) in the upper site abundance estimate. With heterogeneity at all three sites (a subpopulation effect), the upper site estimate had 22.9% to 29.3% negative bias. Because heterogeneity observed in the Chena was probably due to inadequate mixing (related to daytime trap evasion), bias in the upper site estimate was probably small. <p>