The interaction between temperature and dose on the efficacy and biochemical response of Atlantic salmon to hydrogen peroxide treatment for amoebic gill disease

Hydrogen peroxide (H₂O₂) is a commonly used treatment for a range of parasitic diseases of marine finfish, including amoebic gill disease (AGD). While this treatment is partially effective at reducing parasite load, H₂O₂ can have detrimental effects on the host under certain conditions. Treatment temperature and dose concentration are two factors that are known to influence the toxicity of H₂O₂; however, their impact on the outcome of AGD treatment remains unclear. Here, we investigated the effects of treatment temperature (8, 12 or 16°C) and dose concentration (750, 1,000, 1,250 mg/L) on the efficacy of H₂O₂ to treat AGD. We demonstrated that a 20-min bath treatment of H₂O₂ at all doses reduced both parasite load and gross gill score significantly. Parasite load and gross gill score were lowest in the 1,000 mg/L treatment performed at 12°C. At the high dose and temperature combinations, H₂O₂ caused moderate gill damage and a significant increase in the plasma concentration of electrolytes (sodium, chloride and potassium). Taken together, our study demonstrates that higher H₂O₂ treatment temperatures can adversely affect the host and do not improve the effectiveness of the treatment.     

Voter‐Approved Annexations in an Urban Growth Boundary Regime: The Impacts on Housing Values,Density, and Economic Equity

Oregon is known for its strict Urban Growth Boundary (UGB) policies. While UGBs are designed to accommodate land supply for 20 years of growth, land within UGBs must be annexed into city limits before it can be developed at urban densities and serviced. In Oregon, cities use a variety of municipal annexation and voter‐approved annexation policies (VAAPs), providing an opportunity to study how different annexation policies affect land and housing markets, and affect urban density. Previous research on annexation has not considered how annexation policy influences housing values. This paper examines how VAAPs impact land growth, housing development, and density at the city level. It also examines how VAAPs impact housing values. Based on city‐level and tax‐lot‐level statistical analyses from 107 cities outside Portland Metro area, the results suggest that VAAPs negatively impact the availability of developable land within city limits. VAAPs also positively impact residential density and housing value. Lastly, VAAPs inequitably affect housing value between relatively high‐value housing and relatively low‐value housing, posing economic equity impacts for lower value housing. These findings provide important lessons for Oregon and other states. While VAAPs may increase residential density in cities, the policies may exacerbate affordability problems.     

Linking Northeast Pacific recruitment synchrony to environmental variability

We investigated the hypothesis that synchronous recruitment is due to a shared susceptibility to environmental processes using stock–recruitment residuals for 52 marine fish stocks within three Northeast Pacific large marine ecosystems: the Eastern Bering Sea and Aleutian Islands, Gulf of Alaska, and California Current. There was moderate coherence in exceptionally strong and weak year‐classes and correlations across stocks. Based on evidence of synchrony from these analyses, we used Bayesian hierarchical models to relate recruitment to environmental covariates for groups of stocks that may be similarly influenced by environmental processes based on their life histories. There were consistent relationships among stocks to the covariates, especially within the Gulf of Alaska and California Current. The best Gulf of Alaska model included Northeast Pacific sea surface height as a predictor of recruitment, and was particularly strong for stocks dependent on cross‐shelf transport during the larval phase for recruitment. In the California Current the best‐fit model included San Francisco coastal sea level height as a predictor, with higher recruitment for many stocks corresponding to anomalously high sea level the year before spawning and low sea level the year of spawning. The best Eastern Bering Sea and Aleutian Islands model included several environmental variables as covariates and there was some consistent response across stocks to these variables. Future research may be able to utilize these across‐stock environmental influences, in conjunction with an understanding of ecological processes important across early life history stages, to improve identification of environmental drivers of recruitment.     

Long‐term survival and colony growth of Acropora palmata fragments transplanted by volunteers for restoration

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Use of mycophenolate mofetil as a rescue agent in the treatment of severe generalized myasthenia gravis in three dogs

Objective – To describe the use of IV and oral mycophenolate mofetil (MMF) as adjunctive therapy in 3 dogs with severe generalized myasthenia gravis.
Case Series Summary – Three dogs suffering from severe generalized myasthenia gravis as confirmed by acetylcholine antibody titers were treated with MMF as part of their treatment regimens. All 3 dogs had radiographic evidence of megaesophagus and suffered from severe regurgitation. Each dog was initially treated with pyridostigmine and supportive agents. When clinical remission was not achieved, IV MMF was administered to all dogs. Signs of clinical remission were apparent within 48 hours and all dogs were later maintained on oral MMF following resolution of regurgitation.
New or Unique Information Provided – This is the first report of the use of IV MMF as adjunctive treatment in dogs with severe generalized myasthenia gravis. Outcome was favorable in all 3 dogs and no adverse effects were noted from the MMF.     

A modified critical test and its use in two dose titration trials to assess efficacy of praziquantel for Anoplocephala perfoliata in equids

Aims of this study with 43 equids naturally infected with Anoplocephala perfoliata in two dose titration trials were to document (i) the usefulness of a critical test with a 48 h treatment to necropsy period, (ii) efficacy of an oral paste of 0.5-2.0 mg praziquantel/kg body weight, and (iii) when after treatment would fecal egg counts provide best estimates of the tapeworm's prevalence in a herd. All feces passed by an equid after treatment and collected in successive 12 h batches were examined for tapeworms. At necropsy, tapeworms were identified as attached to the mucosa or unattached. Tapeworms were examined with a stereoscope and identified as normal or abnormal. Fecal samples were taken for egg counts at treatment and at 6 h intervals thereafter. In 32 of 36 treated equids, efficacy was 100% and mean efficacies for 0.5, 1.0, 1.5 and 2.0 mg praziquantel/kg body weight were 85.5, 99.7, 100 and 100%, respectively. Two equids treated with 0.5 mg praziquantel/kg body weight had low efficacies (5.4 and 38.1%) and normal tapeworms were found attached in the ventral colon and in one equid also in the dorsal colon. In seven untreated equids, tapeworms were primarily in the cecum with 21.3% detached. "Major fragments" or worms without a scolex but otherwise nearly a complete worm were 20.5% of the number of intact worms; they were not included in the efficacy analysis but should be. If the two equids with low efficacy were eliminated and if the number of all tapeworms and major fragments are combined less than 0.5% were in feces within 12 h of treatment, about 20% were in the 12-24 h period, 42% in 24-36h, 24% in 36-48 h and 13.5% in the equids at necropsy. One horse passed all its tapeworms in 24 h. This 48 h test when compared with a 24 h one with no examination of feces was more efficient in use of trial animals and reduced underestimation and overestimation of efficacy. However, a protocol similar to the 48 h test but with a 24 or 36 h post-treatment period should be investigated. The mean egg count peaked 18-24 h after treatment and samples taken at that time would provide the best estimate of prevalence. The Cornell-Wisconsin centrifugal flotation technique had a specificity of 100% and at 18 and 24 h its sensitivity was 94%. A brief discussion on critical and controlled tests for assessing efficacy of an anthelmintic for A. perfoliata is presented.     

Influence of sulfometuron methyl on conifer seedling root development

On three sites in coastal northwestern Oregon, USA, seedling root and shoot development were assessed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western red-cedar (Thuja plicata Donn ex D. Don) container seedlings under varying sulfometuron methyl (Oust XP^®) herbicide application treatments. Treatments consisted of application of 0.16 kg active ingredient (ai) ha^?1 as a site preparation in fall 2003, a release application in fall 2004, or a control treatment with no application. Seedlings were planted in winter 2004 and measurements recorded in summer 2004, winter 2005, and summer 2005. During first season growth, western red-cedar seedlings showed the greatest negative impact to site preparation compared to the control with overall average new root length outside the root plug reduced by 67%. Significant reductions in root length also occurred for western hemlock (47%) and Douglas-fir (40%) seedlings. About 9 months after the release treatment, and 21 months after the site preparation application, there were no significant differences between treatments for any measured parameter. These findings suggest that seedlings under the site preparation treatment recovered from initial damage incurred to the root system. Lack of seedling response under the release treatment may be the result of opposing influences from the herbicide application associated with seedling phytotoxicity and enhanced seedling development resulting from effective vegetation control. Although our study was limited to 21 months following planting, reduced vegetation cover in the site preparation and release treatments suggests that these treatments may benefit future seedling growth.     

Potassium carryover dynamics and optimal application policies in cotton production

Information about soil nutrient carryover dynamics can assist cotton producers with the optimal management of potassium (K) fertilizer. Optimal K management promotes cotton plant health, may decrease input costs, and increases cotton lint yields. A dynamic programming model was developed to determine optimal K application rates and economic returns under different soil information scenarios based on cotton yield response to K fertilizer and fertilizer carryover estimates from a multi-year field trial. A Monte Carlo analysis was conducted to simulate the impact of stochastic input and lint prices and cotton yield on K management over a five-period planning horizon. Results suggest that soil test data could provide important information about K carryover potential, which may lead to more efficient fertilizer use and higher profit margins for cotton producers.