A Conceptual Model for Predicting Areas with High Potential for Lake Trout Spawning Habitat in Yellowstone Lake

The presence of non-native lake trout (Salvelinus namaycush) has become a serious threat to native salmonid populations in many lakes throughout the West. Costly and time consuming suppression efforts have been undertaken by agencies in several of these systems with concern regarding their efficacy expressed by fisheries managers. Frequently, mature lake trout are interspersed with the native fishes, hindering removal efforts because of bycatch of fishes meant to be the beneficiary of suppression efforts. One method of improving suppression efforts that could reduce negative impacts on other species is to target areas where sexually mature lake trout congregate for spawning activities. Using theory that water movements within lakes influence habitat formation, parameters describing lake trout spawning habitat in published literature, and the capability of a GIS to mesh spatially-explicit geographical datasets, a conceptual lake trout spawning habitat model was developed for Yellowstone Lake. Important inputs to this model include detailed bathymetry of Yellowstone Lake, a sedimentation model that predicts erosion and deposition of particles within lake systems, and data on primary wind direction over the lake. The model predicts that 4.4 percent of the surface area of Yellowstone Lake has excellent potential, 8.9 percent has some potential, and 86.7 percent has no potential to contain lake trout spawning habitat. Additional data layers can be easily incorporated as new information becomes available on lake trout requirements for successful spawning. This model can be used to identify suitable spawning areas for monitoring and control, and has potential to be applied on other lakes experiencing lake trout invasion

An Evaluation of Lake Trout Suppression in Yellowstone Lake, Yellowstone National Park

Introduced lake trout (Salvelinus namaycush) threaten to extirpate native Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) from Yellowstone Lake, Yellowstone National Park. A National Park Service gill netting program has removed nearly 400,000 lake trout from Yellowstone Lake since 1995. Lake trout population size has not been estimated; therefore, it is difficult to determine the proportion that has been removed. Our objectives were to (1) examine catch as a function of effort to determine if the suppression program has caused lake trout abundance to decline, (2) determine if certain population metrics have changed over time as a function of harvest, and (3) develop age-structured models to determine the level of mortality required to cause population growth rate to decline below 1.0 (replacement). Catch has continued to increase as a function of effort, indicating lake trout abundance is increasing. Population metrics were not clearly indicative of a response to harvest, but were comparable to North American lake trout populations where harvest has occurred. Results from an age-structured matrix model determined the rate of population growth was 1.1 given the current rate of fishing mortality and that population growth rate would be 1.3 in the absence of fishing mortality. The current rate of population growth is positive; however, it is slower than it would be in the absence of lake trout suppression. Fishing mortality needs to increase by at least 10 percent to reduce population growth rate below 1.0 in the future

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

Could ecological release buffer suppression efforts for non-native lake trout (Salvelinus namaycush) in Yellowstone Lake, Yellowstone National Park?

Yellowstone Lake in Yellowstone National Park, USA, has the longest ongoing suppression program for non-native lake trout (Salvelinus namaycush) in the western USA. Harvest data from the suppression program, along with data from an assessment program initiated in 2011, was used to estimate lake trout abundance and mortality rates. Abundance and biomass estimates were used to estimate stock-recruitment dynamics, which were inputs to a simulation model forecasting responses to continued suppression. Abundance increased during 1998-2012 when total annual mortality exceeded 0.59 and declined thereafter. The fishing mortality rate required to reduce abundance was 67% greater than predicted by models that used pre-recruit survival estimates from the lake trout’s native range. Pre-recruit survival in Yellowstone Lake was estimated at 4-6 times greater than native range survival rates. Simulated abundance continued to decline if recent suppression efforts were maintained. High pre-recruit survival in Yellowstone Lake likely illustrates ecological release for an invasive species in an ecosystem containing few predators or competitors and demonstrates the potential pitfalls of assuming equal demographic rates for native and non-native populations.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

The distribution of late-Quaternary woody taxa in Eurasia: evidence from a new macrofossil database

We present a database of late-Quaternary plant microfossil records for northern Eurasia (from 23° to 180°E and 46° to 76°N) comprising 281 localities, over 2300 samples and over 13,000 individual records. Samples are individually radiocarbon dated or are assigned ages via age models fitted to sequences of calibrated radiocarbon dates within a section. Tree species characteristic of modern northern forests (e.g. Picea, Larix, tree-Betula) are recorded at least intermittently from prior to the last glacial maximum (LGM), through the LGM and Lateglacial, to the Holocene, and some records locate trees close to the limits of the Scandinavian ice sheet, supporting the hypothesis that some taxa persisted in northern refugia during the last glacial cycle. Northern trees show differing spatio-temporal patterns across Siberia: deciduous trees were widespread in the Lateglacial, with individuals occurring across much of their contemporary ranges, while evergreen conifers expanded northwards to their range limits in the Holocene.The full-text of this article is not available in ORA, but you may be able to access the article via the publisher copy link on this record page

Dietary B vitamin intake and incident premenstrual syndrome123

Background: Thiamine, riboflavin, niacin, vitamin B-6, folate, and vitamin B-12 are required to synthesize neurotransmitters that are potentially involved in the pathophysiology of premenstrual syndrome (PMS)