A comparison of community structure in regulated and unregulated reaches in the Upper Eel River, California

Flow regulation of rivers by impoundments and diversions can reduce hydrological variability. As a result, densities of algae and benthic macroinvertebrates often increase, but many sensitive taxa are lost, causing shifts across the food web. In Northern California, dams that reduce winter peak floods can result in the primary consumer community becoming dominated by grazers that are relatively invulnerable to predation, which can reduce the amount of energy transferred up the trophic levels. The steeper slope of the spring hydrograph recession limb downstream of a dam can also greatly impact instream diversity of periphyton, invertebrates and fish. The dam and diversion system on the upper Mainstem Eel River in Northern California has direct impacts on endangered salmon populations, but the effects of the dams on the greater ecosystem are not well understood. This study compared the seasonal algal and benthic macroinvertebrate communities from the Mainstem Eel River below Cape Horn Dam to that of the unregulated Middle Fork Eel River. The 2017 water year had above average rainfall, with several bankfull flows observed in the winter as well as elevated base flows in the summer in both rivers. Despite the wet water year in 2017, the regulation of flows by the dams still likely produced a shorter spring recession limb and, more importantly, a delay in peak summer temperatures in the Mainstem relative to the Middle Fork. Although the abundance and diversity of invertebrates were not notably different between the regulated and unregulated rivers, there did appear to be a variation in the food webs. By mid-summer, the unregulated Middle Fork developed into an ecosystem predominated by Cladophora and its epiphytes with numerous invertebrate grazers. Yet the Mainstem, especially immediately below the dam with the encroachment of vegetation, had less growth of the filamentous green algae (t(20)=4.61, p=0.0002) with lower mid-summer algal richness ((20)=2.53, p= 0.020), resulting in an invertebrate community more reliant on filtering fine organic matter with far fewer grazers (pCladophoraas well as the abundance and development of some key macroinvertebrate taxa, such as midges and small minnow mayflies relative to an unregulated reach. As the Middle Fork is an inherently warmer system, future studies are needed across a longitudinal gradient of the Mainstem over multiple water years to capture interannual variation and to ultimately determine the influence of the dams on riverine ecosystems

Cost-Effectiveness Evaluation of Etoricoxib versus Celecoxib and Nonselective NSAIDs in the Treatment of Ankylosing Spondylitis in Norway

Objectives. To evaluate the cost-effectiveness of etoricoxib (90 mg) relative to celecoxib (200/400 mg), and the nonselective NSAIDs naproxen (1000 mg) and diclofenac (150 mg) in the initial treatment of ankylosing spondylitis in Norway. Methods. A previously developed Markov state-transition model was used to estimate costs and benefits associated with initiating treatment with the different competing NSAIDs. Efficacy, gastrointestinal and cardiovascular safety, and resource use data were obtained from the literature. Data from different studies were synthesized and translated into direct costs and quality adjusted life years by means of a Bayesian comprehensive decision modeling approach. Results. Over a 30-year time horizon, etoricoxib is associated with about 0.4 more quality adjusted life years than the other interventions. At 1 year, naproxen is the most cost-saving strategy. However, etoricoxib is cost and quality adjusted life year saving relative to celecoxib, as well as diclofenac and naproxen after 5 years of follow-up. For a willingness-to-pay ceiling ratio of 200,000 Norwegian krones per quality adjusted life year, there is a >95% probability that etoricoxib is the most-cost-effective treatment when a time horizon of 5 or more years is considered. Conclusions. Etoricoxib is the most cost-effective NSAID for initiating treatment of ankylosing spondylitis in Norway

Drivers and Dynamics of Phytoplankton Communities and Harmful Algal Blooms in Mountain Lakes

Harmful cyanobacterial blooms (cyanoHABs) are a complex and widespread disturbance in freshwater water bodies, impacting water quality for wildlife and human populations. While cyanobacteria often bloom in warm lakes impacted by human development like agriculture, blooms are increasingly reported in cooler waters with limited development in the surrounding watershed. As much of cyanoHAB research has focused on lakes in highly developed watersheds, the understanding of factors leading to cyanobacteria dominance and blooms in the absence of major development remains limited. Mountain lakes can serve as ideal systems to study bloom-forming cyanobacteria in watersheds with minimal development. In addition, mountain lakes span natural gradients of productivity and climate due to the varied elevation and topography. Mountain lakes are also highly valued for recreation and habitat for sensitive species due to perceived pristine conditions, but are vulnerable to multiple stressors such as climate warming and increased atmospheric deposition of nutrients, which limit cyanobacteria growth. Therefore, the potential for cyanoHABs in mountain lakes is likely to rise in the near future, making it crucial to understand the drivers of cyanobacteria dominance and blooms in these sensitive lakes. The goal of this dissertation is to improve the understanding of drivers and dynamics of bloom-forming cyanobacteria in mountain lakes, including factors across lake to watershed scales, to temporal and spatial patterns in planktonic communities. I conducted field surveys to examine the physical and chemical conditions as well as the phytoplankton and other key biological communities in a set of Cascade Mountain lakes located in Oregon, USA. In Chapter 2, I used survey data and existing geospatial data to identify food web, lake, and watershed drivers, as well as interactions among drivers across scales on nitrogen (N)-fixing cyanobacteria, the common cyanoHAB taxa in the region. In Chapter 3, I examined the intra- and inter-annual variation in cyanoHABs and cyanotoxins relative to meteorological conditions and the bacterioplankton communities. Based on genetic sequencing and time integrated toxin monitoring, I determined possible temporal relationships and biological indicators of blooms and bloom toxicity. In Chapter 4, I used survey data as along with existing and interpolated trait data to assess how the top-down and bottom-up effects of grazing zooplankton and nutrients could have shaped phytoplankton communities functionally. I discuss the resulting implications for bloom-forming cyanobacteria dominance over other phytoplankton. I identified watershed size and hypolimnetic dissolved oxygen as key drivers of N-fixing cyanobacteria biomass likely through the regulation of limiting nutrients such as phosphorus. Temperature and rainfall did not correspond strongly to the blooms and toxins of N-fixing cyanobacteria across lakes, suggesting other meteorological factors as well as lake productivity may be more important. Yet further study is needed with high-frequency sampling and better characterization of meteorological conditions. In terms of the food web, I found grazing cladocerans were a significant factor for N-fixing cyanobacteria, likely via consumption of other phytoplankton. These grazers may be in turn influenced by fish populations. I also found additional biological indicators for cyanobacteria blooms as well as bloom toxicity in heterotrophic bacteria. Finally, I found high grazer abundances favor fast growing and small unicellular phytoplankton at relatively low nutrients, while increasing phosphorus favors colonial cyanobacteria capable of toxin production, such as N-fixing taxa. At high levels of grazers and phosphorus, toxigenic cyanobacteria likely dominate phytoplankton communities in mountain lakes. This dissertation sheds light on the key factors and indicators for N-fixing cyanobacteria dominance and cyanoHABs in mountain lakes. My results suggest that lake management agencies must consider how both landscape and within-lake factors may affect the risk for cyanoHABs, and how fish stocking increases risk via their impact on grazing zooplankton biomass and body size. As mountain lake monitoring is limited, my results suggest genetic identification of bacterial communities may provide a more time-integrated way to assess bloom development and toxicity. Determining how abiotic and biotic factors interact is needed to broaden management approaches since strict nutrient reduction programs have had mixed success in reducing cyanoHABs in lakes

Quick, but Not Dirty:The Usefulness of Flash Mob Studies as a Method for Action Research in eHealth

Action research (AR) is a participatory research approach that works in iterative cycles that are conducted in practice. However, some cycles of AR can take a long time, slowing down the speed of iterations. Therefore, in this study we investigate the use of a relatively new method for AR: the flash mob. Flash mob studies lend themselves to spontaneous, unplanned participation, by collecting large amounts of data in a short time, while also analyzing and reporting quickly on findings. To investigate the applicability of the flash mob as a method for AR in eHealth projects, we conducted three flash mob studies in two research projects and drew recommendations based on observations, reflections and short pre- and post-surveys. Outcomes show that the flash mob is a potential method for AR, as it is situated in a practical setting where stakeholders can easily be involved, and its pace could speed up the AR cycles. To further improve the applicability for AR, our main recommendations include: promoting the flash mob adequately to increase participation and improve the involvement of ‘champions’; tracking interactions outside the flash mob (e.g., comments and questions from bystanders); and choosing an accessible and visible location, taking into account the activities associated with the location

How to Prevent the Drop-Out:Understanding Why Adults Participate in Summative eHealth Evaluations

The aim of this study was to investigate why adults participate in summative eHealth evaluations, and whether their reasons for participating affect their (non-)use of eHealth. A questionnaire was distributed among adults (aged ≥ 18 years) who participated in a summative eHealth evaluation. This questionnaire focused on participants’ reason to enroll, their expectations, and on whether the study met their expectations. Answers to open-ended questions were coded by two researchers independently. With the generalized estimating equations method we tested whether there is a difference between the type of reasons in use of the eHealth service. One hundred and thirty-one adults participated (64.9% female; mean age 62.5 years (SD = 10.5)). Their reasons for participating were mainly health-related (e.g., being more active). Between two types of motivations there was a difference in the use of the eHealth service: Participants with an intellectual motivation were more likely to drop out, compared to participants with an altruistic motivation. The most prevalent expectations when joining a summative eHealth evaluation were health-related (like expecting to improve one’s health). 38.6% of the participants said their expectation was fulfilled by the study. In conclusion, We encourage eHealth evaluators to learn about adults’ motivation to participate in their summative evaluation, as this motivation is very likely to affect their results. Including altruistically motivated participants biases the results by their tendency to continue participating in a study.</p