Tidal Estuary Morphodynamics of the Knik Arm

Presented to the Faculty of the University of Alaska Anchorage in Partial Fulfillment of the Requirements For the Degree of MASTER OF CIVIL ENGINEERINGA three-dimensional unsteady flow numerical model was developed to study sediment transport due to tidal circulation within Knik Arm, a dynamic well mixed macro-tidal sub-estuary of Cook Inlet in Alaska. The model was developed to gain a better understanding of the mechanisms that are creating the Point MacKenzie Shoal, located approximately 4 kilometers south of Port MacKenzie. Hydrodynamic conditions within the estuary are very complex in that ebb-and-flood tides, freshwater mixing, and wetting/drying of tidal mud flats significantly effects sediment transport within the estuary. A Mike 3 numerical model was applied to simulate the sediment transport within the estuary under the action of tidal currents in the vicinity of the shoal. The computational domain of this simulation includes four sediment laden freshwater sources; Matanuska, Knik, Susitna, and Twenty-Mile Rivers as well as an open ocean boundary. The spatial resolution of the triangulated flexible mesh model is 0.00045 degrees2 with a coupled fine resolution model of 0.000045 degrees2. The results of the numerical model are in agreement with previously collected field data. Simulation results indicate the shoal formation is the result of turbid tidal flows and deposition is occurring naturally.Signature Page / Title Page / Abstract / Table of Contents / List of Figures / List of Tables / Background / Introduction / Physical Setting / Sediment / Freshwater Sources / Water Properties / Tidal Datum / Numerical Model / Model Selection / Methodology / Model Domain / Hydrodynamics / Sediment Transport / Summary of Model Input / Results and Discussion / Conclusion / Acknowledgments Reference

Reproduction and Dispersal of Biological Soil Crust Organisms

Biological soil crusts (BSCs) consist of a diverse and highly integrated community of organisms that effectively colonize and collectively stabilize soil surfaces. BSCs vary in terms of soil chemistry and texture as well as the environmental parameters that combine to support unique combinations of organisms—including cyanobacteria dominated, lichen-dominated, and bryophyte-dominated crusts. The list of organismal groups that make up BSC communities in various and unique combinations include—free living, lichenized, and mycorrhizal fungi, chemoheterotrophic bacteria, cyanobacteria, diazotrophic bacteria and archaea, eukaryotic algae, and bryophytes. The various BSC organismal groups demonstrate several common characteristics including—desiccation and extreme temperature tolerance, production of various soil binding chemistries, a near exclusive dependency on asexual reproduction, a pattern of aerial dispersal over impressive distances, and a universal vulnerability to a wide range of human-related perturbations. With this publication, we provide literature-based insights as to how each organismal group contributes to the formation and maintenance of the structural and functional attributes of BSCs, how they reproduce, and how they are dispersed. We also emphasize the importance of effective application of molecular and microenvironment sampling and assessment tools in order to provide cogent and essential answers that will allow scientists and land managers to better understand and manage the biodiversity and functional relationships of soil crust communities

Chimpanzees demonstrate individual differences in social information use

Studies of transmission biases in social learning have greatly informed our understanding of how behaviour patterns may diffuse through animal populations, yet within-species inter-individual variation in social information use has received little attention and remains poorly understood. We have addressed this question by examining individual performances across multiple experiments with the same population of primates. We compiled a dataset spanning 16 social learning studies (26 experimental conditions) carried out at the same study site over a 12-year period, incorporating a total of 167 chimpanzees. We applied a binary scoring system to code each participant’s performance in each study according to whether they demonstrated evidence of using social information from conspecifics to solve the experimental task or not (Social Information Score—‘SIS’). Bayesian binomial mixed effects models were then used to estimate the extent to which individual differences influenced SIS, together with any effects of sex, rearing history, age, prior involvement in research and task type on SIS. An estimate of repeatability found that approximately half of the variance in SIS was accounted for by individual identity, indicating that individual differences play a critical role in the social learning behaviour of chimpanzees. According to the model that best fit the data, females were, depending on their rearing history, 15–24% more likely to use social information to solve experimental tasks than males. However, there was no strong evidence of an effect of age or research experience, and pedigree records indicated that SIS was not a strongly heritable trait. Our study offers a novel, transferable method for the study of individual differences in social learning

Regular Tart Cherry Intake Alters Abdominal Adiposity, Adipose Gene Transcription, and Inflammation in Obesity-Prone Rats Fed a High Fat Diet

Abstract Obesity, systemic inflammation, and hyperlipidemia are among the components of metabolic syndrome, a spectrum of phenotypes that can precede the development of type 2 diabetes and cardiovascular disease. Animal studies show that intake of anthocyanin-rich extracts can affect these phenotypes. Anthocyanins can alter the activity of tissue peroxisome proliferator-activated receptors (PPARs), which affect energy substrate metabolism and inflammation. However, it is unknown if physiologically relevant, anthocyanin-containing whole foods confer similar effects to concentrated, anthocyanin extracts. The effect of anthocyanin-rich tart cherries was tested in the Zucker fatty rat model of obesity and metabolic syndrome. For 90 days, rats were pair-fed a higher fat diet supplemented with either 1% (wt/wt) freeze-dried, whole tart cherry powder or with a calorie- and macronutrient-matched control diet. Tart cherry intake was associated with reduced hyperlipidemia, percentage fat mass, abdominal fat (retroperitoneal) weight, retroperitoneal interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression, and plasma IL-6 and TNF-α. Tart cherry diet also increased retroperitoneal fat PPAR-α and PPAR-γ mRNA (P=.12), decreased IL-6 and TNF-α mRNA, and decreased nuclear factor κB activity. In conclusion, in at-risk obese rats fed a high fat diet, physiologically relevant tart cherry consumption reduced several phenotypes of metabolic syndrome and reduced both systemic and local inflammation. Tart cherries may reduce the degree or trajectory of metabolic syndrome, thereby reducing risk for the development of type 2 diabetes and heart disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78120/1/jmf.2008.0270.pd

Blueberry Intake Alters Skeletal Muscle and Adipose Tissue Peroxisome Proliferator-Activated Receptor Activity and Reduces Insulin Resistance in Obese Rats

Metabolic syndrome can precede the development of type 2 diabetes and cardiovascular disease and includes phenotypes such as obesity, systemic inflammation, insulin resistance, and hyperlipidemia. A recent epidemiological study indicated that blueberry intake reduced cardiovascular mortality in humans, but the possible genetic mechanisms of this effect are unknown. Blueberries are a rich source of anthocyanins, and anthocyanins can alter the activity of peroxisome proliferator-activated receptors (PPARs), which affect energy substrate metabolism. The effect of blueberry intake was assessed in obesity-prone rats. Zucker Fatty and Zucker Lean rats were fed a higher-fat diet (45% of kcal) or a lower-fat diet (10% of kcal) containing 2% (wt/wt) freeze-dried whole highbush blueberry powder or added sugars to match macronutrient and calorie content. In Zucker Fatty rats fed a high-fat diet, the addition of blueberry reduced triglycerides, fasting insulin, homeostasis model index of insulin resistance, and glucose area under the curve. Blueberry intake also reduced abdominal fat mass, increased adipose and skeletal muscle PPAR activity, and affected PPAR transcripts involved in fat oxidation and glucose uptake/oxidation. In Zucker Fatty rats fed a low-fat diet, the addition of blueberry also significantly reduced liver weight, body weight, and total fat mass. Finally, Zucker Lean rats fed blueberry had higher body weight and reduced triglycerides, but all other measures were unaffected. In conclusion, whole blueberry intake reduced phenotypes of metabolic syndrome in obesity-prone rats and affected PPAR gene transcripts in adipose and muscle tissue involved in fat and glucose metabolism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90448/1/jmf-2E2010-2E0292.pd