Genetic stock identification (GSI) is widely applied to mixed-stock fisheries for many commercially exploited species. However, the accuracy of GSI depends on the level of differentiation among stocks. To evaluate our ability to estimate contributions in mixed-stock fisheries of Pink Salmon Oncorhynchus gorbuscha, a species with limited population genetic differentiation, we analyzed 46 odd-year Pink Salmon stocks belonging to a baseline of genotypes from southern British Columbia, the Fraser River, and Puget Sound. Samples were obtained without replacement from the baseline (known mixtures), and 16 microsatellite loci were used for analysis with two software packages (cBayes and ONCOR) to evaluate the accuracy of using this marker set to identify the correct region, subregion, and spawning site. The correct subregion was identified for Pink Salmon from southern British Columbia and Puget Sound. However, incorrect assignments were observed for the Fraser River subregions and the stock-specific estimates. In addition, we used simulated baselines with the average genetic differentiation index F ST ranging from 0.0007 to 0.04 (the range of F ST values observed in Pink Salmon stocks) to identify biases in the GSI software programs. The results suggested that stock-level genetic identification is subject to significant biases (>15%) when the average F ST among baseline stocks is less than 0.01. ONCOR was more accurate than cBayes in identifying the correct stock at small mean F ST values (<0.01), but there was no significant difference between the software packages at larger F ST values. Our results can help to improve GSI methods and to identify their limitations, especially for stocks with low genetic separation.

Two distinct populations of resident killer whales (Orcinus orca) in the north‐eastern Pacific Ocean have been listed in Canada and the USA as being of conservation concern. One of the major threats recognized for these two populations is nutritional stress associated with prey abundance levels and availability. The predominance of chinook salmon (Oncorhynchus tshawytscha) in the summer diets of both killer whale populations has been shown by recent studies, and correlations between indices of chinook salmon abundance and resident killer whale (RKW) vital rates have generated hypotheses about the potential for chinook salmon abundance to limit RKW population dynamics. This study merges statistical inference derived from linkages between RKW vital rates (survival probability and fecundity rates) and chinook salmon abundance with demographic perturbation analysis and population viability analysis to address some of the pressing questions that have recently engaged the efforts of scientists and managers interested in: (1) the role of chinook salmon abundance in the population dynamics of RKW; and (2) how RKW population viability is expected to respond to changes in chinook mortality owing to harvest. Numerous interactions between the abundance of chinook salmon aggregates and RKW vital rates were found and deemed to result from predator–prey dynamics. However, the results of this present analysis also indicated that the effects of these interactions on RKW population growth and viability are relatively small and/or uncertain and in need of further research. Other factors (genetic, environmental and/or anthropogenic) could be at play limiting RKW population growth and possibly masking and confounding the detection of stronger interactions between RKW vital rates and chinook salmon abundance. Given the current state of information, it is highly uncertain whether the allocation of chinook salmon resources for RKW would be an effective management action in RKW recovery plans. © 2014 Her Majesty the Queen in Right of Canada Ecohydrology © 2014 John Wiley & Sons, Ltd.

A few years ago the endocannabinoid system has been recognized as a major neuromodulatory system whose main functions are to exert and maintain the body homeostasis. Several different endocannabinoids are synthesized in a broad class of cell types, including those in the brain and the immune system; they bind to cannabinoid G-protein-coupled receptors, having profound effects on a variety of behavioral, neuroendocrine and autonomic functions. The coordinated neural, immune, behavioral and endocrine responses to inflammation are orchestrated to provide an important defense against infections and help homeostasis restoration in the body. These responses are executed and controlled mainly by the hypothalamic-pituitary adrenal axis. Also, the hypothalamic-neurohypophyseal system is essential for survival and plays a role recovering the homeostasis under a variety of stress conditions, including inflammation and infection. Since the endocannabinoid system components are present at sites involved in the hypothalamic-pituitary axis regulation, several studies were performed in order to investigate the endocannabinoid-mediated neurotransmitters and hormones secretion under physiological and pathological conditions. In the present review we focused on the endocannabinoids actions on the neuroendocrine response to inflammation and infection. We provide a detailed overview of the current understanding of the role of the endocannabinoid system in the recovering of homeostasis as well as potential pharmacological therapies based on the manipulation of endocannabinoid system components that could provide novel treatments for a wide range of disorders.

A total of 107 Mapuche Indians living in western Argentina were studied with respect to 16 genetic systems. For HLA, there were a few differences in relation to previous studies; and considering the averages observed in 15 other South American tribes, Mapuche Indians showed low values for A2, A9 and C3, but high ones for A28 and B16. This is the first report of the presence (in low frequencies, 1–6%) of alleles C2, C6 and C7, as well as of DR antigens (most frequent alleles DR4 and DR2) in South American Indians. Some peculiar reactions shown by products of locus B suggest the presence of antigens that are characteristic of the Mapuche. As for the other systems, the frequencies of R¹ (Rh) and PGM¹₁ were lower but those for r (Rh), GLO¹ and Hp¹ were higher than the averages obtained considering previous studies of this ethnic group. Other salient findings were the variability observed in the PGM2 and C3 systems, and the low prevalence of Bf^S.

Abstract:Sediment rating curves are commonly used to estimate the suspended sediment load in rivers and streams under the assumption of a constant relation between discharge (Q) and suspended sediment concentrations (SSC) over time. However, temporal variation in the sediment supply of a watershed results in shifts in this relation by increasing variability and by introducing nonlinearities in the form of hysteresis or a path-dependent relation. In this study, we used a mixed-effects linear model to estimate an average SSC-Q relation for different periods of time within the hydrologic cycle while accounting for seasonality and hysteresis. We tested the performance of the mixed-effects model against the standard rating curve, represented by a generalized least squares regression, by comparing observed and predicted sediment loads for a test case on the Chilliwack River, British Columbia, Canada. In our analyses, the mixed-effects model reflected more accurate patterns of interpolated SSC from Q data than the rating curve, especially for the low-flow summer months when the SSC-Q relation is less clear. Akaike information criterion scores were lower for the mixed-effects model than for the standard model, and the mixed-effects model explained nearly twice as much variance as the standard model (52% vs 27%). The improved performance was achieved by accounting for variability in the SSC-Q relation within each month and across years for the same month using fixed and random effects, respectively, a characteristic disregarded in the sediment rating curve.