Incorporating Climate Change Predictions in Ecological Risk Assessment: A Bayesian Network Relative Risk Model for Chinook Salmon in the Skagit River Watershed

Climate change is expected to have widespread impacts on future ecosystem services in the Puget Sound and around the world. It is important that climate change be included in ecological risk assessment so that changing climate variables and potential interactive effects with chemical stressors can be taken into account. In this research, I focused on the question of how water temperature changes generated by climate change interact with organophosphate pesticide toxicity to affect Chinook salmon (Oncorhynchus tshawytscha) population size in the Skagit River, WA. To answer this question, I conducted an ecological risk assessment using the Bayesian network relative risk model (BN-RRM). It is a quantitative, probability-based approach that calculates complex relationships between ecological variables in a cause-and-effect framework to provide estimates of risk to valued receptors (endpoints). I used region and season specific measurement data for water temperature, dissolved oxygen, chlorpyrifos concentration, and diazinon concentration as the model input. Climate predictions were based on model output between the years 2071 and 2100 from an ensemble of global climate models (GCMs) selected from the Fifth Coupled Model Intercomparison Project (CMIP5). The probability of Chinook salmon population decline, before climate change predictions were taken into account, ranged between 77.1% and 64.0% depending on region and season. I found climate change caused changes in water temperature influenced risk in different ways depending on the region and season. The probability of Chinook population decline increased by up to 4.2% in different regions and seasons. I used sensitivity analysis of the BN-RRM to analyze which stressors had the most influence on Chinook salmon population size. I found that the environmental stressors of water temperature and dissolved oxygen had the most influence, which suggests habitat remediation may be an effective strategy for addressing risk to Chinook salmon in the Skagit River. This research demonstrates that climate change scenarios can be successfully incorporated into ecological risk assessment using the BN-RRM. This approach can be easily adapted to other watersheds and allows for the inclusion of additional stressors and/or endpoints

Hydraulic adjustment to an obstacle in a rotating channel

Author Posting. © Cambridge University Press, 2000. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 404 (2000):117-149, doi:10.1017/S0022112099007065.In order to gain insight into the hydraulics of rotating-channel flow, a set of initial-value problems analogous to Long's towing experiments is considered. Specifically, we calculate the adjustment caused by the introduction of a stationary obstacle into a steady, single-layer flow in a rotating channel of infinite length. Using the semigeostrophic approximation and the assumption of uniform potential vorticity, we predict the critical obstacle height above which upstream influence occurs. This height is a function of the initial Froude number, the ratio of the channel width to an appropriately defined Rossby radius of deformation, and a third parameter governing how the initial volume flux in sidewall boundary layers is partitioned. (In all cases, the latter is held to a fixed value specifying zero flow in the right-hand (facing downstream) boundary layer.) The temporal development of the flow according to the full, two-dimensional shallow water equations is calculated numerically, revealing numerous interesting features such as upstream-propagating shocks and separated rarefying intrusions, downstream hydraulic jumps in both depth and stream width, flow separation, and two types of recirculations. The semigeostrophic prediction of the critical obstacle height proves accurate for relatively narrow channels and moderately accurate for wide channels. Significantly, we find that contact with the left-hand wall (facing downstream) is crucial to most of the interesting and important features. For example, no instances are found of hydraulic control of flow that is separated from the left-hand wall at the sill, despite the fact that such states have been predicted by previous semigeostrophic theories. The calculations result in a series of regime diagrams that should be very helpful for investigators who wish to gain insight into rotating, hydraulically driven flow.The authors have been supported by the National Science Foundation through Grants (OCE-9810599 for L.J.P. and K.R.H. and OCE-9711186 for EPC). L.J.P. also received support from the Office of Naval Research under Grant N00014-95-1-0456 and K.R.H. under grant N00014-93-1-0263

ENTRAINMENT DURING BICYCLE ERGOMETRY IN ELITE CYCLISTS

While it is widely accepted that ventilation increases abruptly at the onset of muscular exercise (D'Angelo and Torelli, 1971; Jensen, Vejby-Christensen and Petersen, 1972; Krogh and Lin~~ard, 1913) the control of the respiratory pattern, i.e., the relationship between ventilation (V', Vi', Ve'), tidal volume (Vt), and respiratory frequency (fR) or respiratory cycle times (Tt, Ti, Te) is not clearly understood (Wasserman, 1978). There are a number of factors, which may be classified as humoral, neurogenic, or neurohumoral, involved in respiratory regulation (Dejours, 1960), but the importance of any single factor is difficult to determine because of the associated problems of controlling for the other variables involved in the total response. One such factor is the coordination of the respiratory pattern to the movement pattern referred to as entrainment. The purpose of the present study was to examine the relationship between the variables that control the respiratory pattern and to test the hypothesis that entrainment would be more prevalent in athletes who were highly trained for a particular mode of exercise, based on a work minimization theory (Priban and Fincham, 1965; Yamashiro and Grodins, 1973; Cherniack, 1980), than in non-athletes unaccustomed to the exercise

Treatment of Streptozotocin-Induced Diabetic Rats with Alogliptin: Effect on Vascular and Neural Complications

We sought to determine the effect of dipeptidyl peptidase IV (DPP-IV) inhibition on streptozotocin diabetes-induced vascular and neural dysfunction. After 4 weeks of untreated diabetes, rats were treated for 12 weeks with Alogliptin (DPP-IV inhibitor). Diabetes caused a slowing of motor and sensory nerve conduction velocity, thermal hypoalgesia, reduction in intraepidermal nerve fiber density in the hindpaw, and impairment in vascular relaxation to acetylcholine and calcitonin gene-related peptide in epineurial arterioles. Treatment significantly improved motor nerve conduction velocity and thermal response latency. Sensory nerve conduction velocity was marginally improved with treatment of diabetic rats, and treatment did not improve the decrease in intraepidermal nerve fiber density. Vascular relaxation by epineurial arterioles to calcitonin gene-related peptide but not acetylcholine was significantly improved with treatment. These studies suggest that some but not all vascular and neural complications associated with type 1 diabetes can be improved with the inhibition of DPP-IV activity

Higher-order unfolding of satellite heterochromatin is a consistent and early event in cell senescence

Epigenetic changes to chromatin are thought to be essential to cell senescence, which is key to tumorigenesis and aging. Although many studies focus on heterochromatin gain, this work demonstrates large-scale unraveling of peri/centromeric satellites, which occurs in all models of human and mouse senescence examined. This was not seen in cancer cells, except in a benign senescent tumor in vivo. Senescence-associated distension of satellites (SADS) occurs earlier and more consistently than heterochromatin foci formation, and SADS is not exclusive to either the p16 or p21 pathways. Because Hutchinson Guilford progeria syndrome patient cells do not form excess heterochromatin, the question remained whether or not proliferative arrest in this aging syndrome involved distinct epigenetic mechanisms. Here, we show that SADS provides a unifying event in both progeria and normal senescence. Additionally, SADS represents a novel, cytological-scale unfolding of chromatin, which is not concomitant with change to several canonical histone marks nor a result of DNA hypomethylation. Rather, SADS is likely mediated by changes to higher-order nuclear structural proteins, such as LaminB1

The Incumbent Advantage in Twin Cities Mayoral Races: The Economy is Good and Crime May Not Drive Voters

Mayoral elections in the Twin Cities are generally kind to incumbents. Since the early 1970s, 6 incumbents have run for reelection in St. Paul and none have lost. In Minneapolis, the incumbent has won 4 out of the last 5 elections dating back to 1981. In terms of basic living conditions, there are no major storm clouds threatening to roil voters in the Twin Cities. Overall economic conditions are good. Violent crime is up in both cities but historically this has not been associated with the downfall of incumbents. The generally favorable economic conditions do not, however, guarantee the re-election of St. Paul Mayor Randy Kelly and Minneapolis Mayor R.T. Rybak. Short-term factors like the partisan anger at Mayor Kelly’s endorsement of President George W. Bush may also affect the campaigns.Center for the Study of Politics and Governance, Humphrey School of Public Affairs, UM

Making History: Governor Pawlenty’s Transportation Veto and A Legislative Override

Governor Tim Pawlenty’s veto on February 22nd of a controversial transportation bill has set the stage for the DFL-controlled legislature to attempt an override. Governor Pawlenty has deployed the veto more often than all but 2 of his predecessors over the past 70 years, but a rare override by the legislature would also make the record books.Center for the Study of Politics and Governance, Humphrey School of Public Affairs, UM

Physical Function in Young and Older Adult Active Pickleball Players

Limited information exists on pickleball’s impact on physical function in adults, especially older adults (65+ years), despite reported health benefits. PURPOSE: This study evaluated the physical function of active older adult (OA) female and male recreational pickleball players via handgrip strength and fatigue, 6-minute walk distance (6MWD) test, as well as the short physical performance battery (SPPB) compared to sex-matched young adult (YA) controls. METHODS: Thirty YA (18-26 years; n=15 female/male) participants and 27 OA (65-89 years; n=13 female, n=15 male) participants who played pickleball at least three times per week were assessed for physical function outcomes of handgrip strength (HGS) and fatigue (HGF), 6-minute walk distance (6MWD), and the short physical performance battery (SPPB). A two-way ANOVA (age x sex) with repeated measures and Sidak post-hoc test were used (pRESULTS: Compared to sex-matched YA, OA women and men had significantly (p2). Absolute HGF followed the absolute HGS results. In contrast, compared to sex-matched YA, no significant differences (p\u3e0.05) were observed in OA women and men for 6MWD percent predicted (which factored in anthropometrics, age, gender, and activity levels; range: 104.6-115.4%) and the overall SPPB (range: 11.3-12.0) as well as each portion of the SPPB (balance, gait speed, and lower limb strength). CONCLUSION: In OA female and male recreational pickleballers, lower body physical function (e.g., walking speed/distance, balance, lower body strength) is largely maintained compared to sex-matched YA pickleballers, but upper body strength/fatigue were not. Pickleball should be combined with meeting resistance training guidelines to maintain whole body physical function with aging