The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. 
The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. 
The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. 
The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

A new species

Generalized Linear Models (2nd ed.)

The Analysis of Variance.

Ninety-eight percent of recently surveyed papers in fisheries and aquatic sciences that did not reject some null hypothesis (H0) failed to report β, the probability of making a type II error (not r...

Statistical Power Analysis can Improve Fisheries Research and Management

Successful application of fish-revival techniques in commercial fishing prior to release of nontarget species requires clear evidence that recovery devices do indeed improve physiological status and minimize postcapture delayed mortality. This study provides such evidence for a newly designed recovery box (Fraser box) that assisted gill ventila - tion. Immediately after capture by gillnet, adult coho salmon (Oncorhynchus kisutch) were in a state of severe meta- bolic exhaustion and stress, based on a comprehensive analysis of plasma and muscle tissue. However, when placed in a Fraser recovery box for 1-2 h, both lethargic and vigorous fish showed significant metabolic recovery and their abil - ity to swim was also quickly restored. An emphatic demonstration of the benefit of the Fraser box was the successful revival of >90% of fish that appeared dead at capture. Furthermore, postcapture delayed mortality was only 2.3% after a 24-h observation period. Therefore, in the context of commercial salmon gillnet fishing, revival of nontarget coho salmon in a Fraser box, in combination with a soak time (total time the gillnet is in the water) 70 min and careful fish handling to minimize physical trauma, could improve physiological status, restore swimming ability, and markedly reduce postcapture delayed mortality. Farrell et al.

Successful recovery of the physiological status of coho salmon on board a commercial gillnet vessel by means of a newly designed revival box

This study compared sea lice (Lepeophtheirus salmonis) infestation rates on juvenile pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon in five nearshore areas of the British Columbia coast selected on the basis of proximity to salmon farms. A 10-week study in the Broughton Archipelago found sea lice were 8.8 times more abundant on wild fish near farms holding adult salmon and 5.0 times more abundant on wild fish near farms holding smolts than in areas distant from salmon farms. We found that 90% of juvenile pink and chum salmon sam- pled near salmon farms in the Broughton Archipelago were infected with more than 1.6 lice·(g host mass) -1 , a pro- posed lethal limit when the lice reach mobile stages. Sea lice abundance was near zero in all areas without salmon farms. Salinity and temperature differences could not account for the higher infestation rates near the fish farms. The most immature life stages dominated the lice population throughout the study, suggesting the source of lice was a sta- tionary, local salmonid population. No such wild population could be identified. The evidence from this control-impact study points to a relationship between salmon farms and sea lice on adjacent, wild, juvenile salmon. Resume : Notre etude compare les taux d'infestation des poux de mer (Lepeophtheirus salmonis) chez le saumon rose (Oncorhynchus gorbuscha) et le saumon keta (Oncorhynchus keta) dans cinq regions cotieres de la Co-

/pdf/sea-lice-lepeophtheirus-salmonis-infection-rates-on-juvenile-4c5ujv2upl.pdf

Sea lice (Lepeophtheirus salmonis) infection rates on juvenile pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon in the nearshore marine environment of British Columbia, Canada

We use the so-called “bent-cable” model to describe natural phenomena that exhibit a potentially sharp change in slope. The model comprises two linear segments, joined smoothly by a quadratic bend. The class of bent cables includes, as a limiting case, the popular piecewise-linear model (with a sharp kink), otherwise known as the broken stick. Associated with bent-cable regression is the estimation of the bend-width parameter, through which the abruptness of the underlying transition may be assessed. We present worked examples and simulations to demonstrate the regularity and irregularity of bent-cable regression encountered in finite-sample settings. We also extend existing bent-cable asymptotics that previously were limited to the basic model with known linear slopes of 0 and 1. Practical conditions on the design are given to ensure regularity of the full bent-cable estimation problem if the underlying bend segment has nonzero width. Under such conditions, the least-squares estimators are shown to be co...

https://faculty.washington.edu/gchiu/Articles/bentcable-jasa.pdf

Bent-Cable Regression Theory and Applications

Microbial communities in wetlands of the Athabasca oil sands: genetic and metabolic characterization

To reduce mortality in the by-catch of commercial salmon fisheries, techniques are being explored to revive fish before live release and improve survival. By measuring blood and muscle variables, w...

Richard Routledge

Papers

Successful recovery of the physiological status of coho salmon on board a commercial gillnet vessel by means of a newly designed revival box

Sea lice (Lepeophtheirus salmonis) infection rates on juvenile pink (Oncorhynchus gorbuscha) and chum (Oncorhynchus keta) salmon in the nearshore marine environment of British Columbia, Canada

Bent-Cable Regression Theory and Applications

Microbial communities in wetlands of the Athabasca oil sands: genetic and metabolic characterization

Rapid recovery of exhausted adult coho salmon after commercial capture by troll fishing