Prospects for the future of pink salmon in three oceans: From the native Pacific to the novel Arctic and Atlantic

While populations of other migratory salmonids suffer in the Anthropocene, pink salmon (Oncorhynchus gorbusca Salmonidae) are thriving, and their distribution is expanding both within their natural range and in the Atlantic and Arctic following introduction of the species to the White Sea in the 1950s. Pink salmon are now rapidly spreading in Europe and even across the ocean to North America. Large numbers of pink salmon breed in Norwegian rivers and small numbers of individuals have been captured throughout the North Atlantic since 2017. Although little is known about the biology and ecology of the pink salmon in its novel distribution, the impacts of the species' introduction are potentially highly significant for native species and watershed productivity. Contrasts between pink salmon in the native and extended ranges will be key to navigating management strategies for Atlantic nations where the pink salmon is entrenching itself among the fish fauna, posing potential threats to native fish communities. One key conclusion of this paper is that the species' heritable traits are rapidly selected and drive local adaptation and evolution. Within the Atlantic region, this may facilitate further establishment and spread. The invasion of pink salmon in the Atlantic basin is ultimately a massive ecological experiment and one of the first examples of a major faunal change in the North Atlantic Ocean that is already undergoing rapid changes due to other anthropogenic stressors. New research is urgently needed to understand the role and potential future impacts of pink salmon in Atlantic ecosystems.     

Nitrogen metabolism and milk production in dairy cows fed semi‐restricted amounts of ryegrass–legume silage with birdsfoot trefoil (Lotus corniculatus L.) or white clover (Trifolium repens L.)

In change‐over trials, mid‐lactation dairy cows were fed concentrate‐supplemented, isonitrogenous and isofibrous perennial ryegrass–legume silage diets that satisfied energy requirements but were suboptimal with respect to metabolizable protein supply. Legumes were either birdsfoot trefoil with low levels of condensed tannins (typical for hemiboreal conditions), or white clover. Averaged over two experimental years, birdsfoot trefoil–based silage resulted in lower digestibility (P < 0·001) of dry matter (50 g kg^?1), organic matter (52 g kg^?1), neutral detergent fibre (120 g kg^?1) and nitrogen (24 g kg^?1) and lower rumen total volatile fatty acid concentration (7 mm ; P = 0·009). Milk protein yield was 36 g d^?1 higher with birdsfoot trefoil silage (P = 0·002), while raw milk yield tended to be 0·8 kg d^?1 higher (P = 0·06). Rumen ammonia concentration was similar between diets, but milk urea concentration (P < 0·001), urinary urea excretion (P = 0·002) and faecal‐N proportion (P = 0·001) were higher with birdsfoot trefoil silage. The results suggest that grass–birdsfoot trefoil silage produced in hemiboreal areas exhibits a protein‐sparing effect in dairy rations, despite a low condensed tannin content that is further diluted by companion grasses and ration concentrate proportion.     

The life-cycle and seasonal abundance of Echinoparyphium montgomeriana n. sp. (Trematoda: Echinostomatidae) in Natal,South Africa

A new species of Echinoparyphium, E. montgomeriana, is described from Durban, South Africa. Certain unusual aspects of its morphology are discussed. The adult fluke is a parasite of the alimentary tract of birds. Its larval stages are common parasites of freshwater snails belonging to the family Planor-bidae including Buiinus africanus,the intermediate host ofSchistosoma haematobium and S. mattheei in the area. These intra-molluscan stages are shown to have a seasonal transmission cycle.     

Risk and economic sustainability of crop farming systems

In economic terms, resilience in farming has to do with the capacity of a farm business to survive various risks and other shocks. Despite its importance, resilience has seldom been directly considered in evaluations of economic sustainability. A whole-farm stochastic simulation model over a 6-year planning horizon was used to analyse organic and conventional cropping systems using a model of a representative farm in Eastern Norway. The relative economic sustainability of alternative systems under changing assumptions about future technology and price regimes was examined in terms of financial survival to the end of the planning period. The same alternatives were also compared in terms of stochastic efficiency. To model the risk of business failure adequately there is a need to deal with the risk of bankruptcy, and a modification of traditional analysis was used for that purpose. The organic farming system was found to be somewhat less economically sustainable than the conventional system, especially if the organic price premiums and the organic area payments were to be phased out. The results illustrate possible conflicts between pursuit of risk efficiency and economic sustainability. The model developed could be used to support farmers’ choices between farming systems as well as to help policy makers develop more sharply targeted policies.     

Dairy cattle crossbreeding in the tropics: Choice of crossbreeding strategy

Summary Two strategies for crossbreeding of indigenous and exotic cattle for milk production in the tropics,viz. rotational crossing and formation of a composite breed, have been compared. Genetic considerations suggest that rotational crossing would lead to somewhat better dairy performance, mainly because of more heterozygosity. Predictions based on the performance of adjacent genetic groups as obtained from a comprehensive literature review point in the same direction.Rotational crossbreeding depends on a continuous introduction of bulls of both parental breeds. The herd will consist of 2 (or more) genetic groups, which might be inconvenient for breeding arrangements, but provides more flexibility. The system requires good organisation and is most suitable in large farms. In small scale dairying the composite breed strategy is the most practical approach to dairy cattle breeding in the tropics.

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Cruzamiento De Vacuno Lechero En Los Tropicos: Eleccion De La Estrategia De Cruzamiento

Resumen El artículo compara dos estrategias de cruzamiento entre vacuno lechero exótico e indígena en los trópicos: el cruzamiento rotativo y la formación de una raza híbrida. Las consideraciones genéticas sugieren que el cruzamiento rotativo debería llevar a una mejor producción lechera, sobre todo debido a un aumento de la heterozigosis. Las predicciones basadas en el rendimiento de grupos genéticos adyacentes determinado a partir de una revisión bibliográfica apuntan en la misma dirección.El cruzamiento rotativo require una introducción contínua de toros de las dos razas parentales. El rebaño consistiría de 2 (o más) grupos genéticos, lo que -si bien permite una mayor flexibilidad- puede dificultar la planificación de la reproducción. El sistema requiere una buena organización y resulta más factible en explotaciones grandes. En explotaciones pequeñas de los trópicos, la formación de una raza híbrida es la estrategia más prática en lo que a cría de vacuno lechero se refiere.

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Croisement Du Cheptel Laitier Sous Les Tropiques: Choix De La Strategie De Croisement

Résumé Deux stratégies pour le croisement entre le bétail indigène et le bétail exotique pour la production laitière sous les Tropiques, à savoir le croisement rotationnel et la formation d'une race composite, ont été comparées. Des considérations génétiques suggèrent que le croisement rotationnel amènerait quelque chose de plus performant au niveau laitièr, principalement dù à l'augmentation de hétérozygotie. Des prédictions, basées sur les performances de groupes génétiques adjacents, issues de l'étude complète de la littérature donnent la même analyse.Le croisement rotationnel est basé sur l'introduction continuelle de taureaux venant des deux races parentales. La horde consistera en 2 (ou plus) groupes génétiques, ce qui peut être gênant pour le croisement mais permet plus de flexibilité. Le système demande une bonne organisation et est préférable dans les grandes fermes. A une échelle de production laitiere plus faible la stratégie de la race composite est l'approche la plus pratique pour le croisement du cheptel laitier sous les Tropiques.

     

Genetic selection for voluntary alcohol consumption in the albino rat

By outbreeding Wistar rats and selecting for breeding animals that differ in their alcohol consumption, we have raised two genetically different lines. Marked differences between the sexes and the strains were evident by the eighth generation. Selection is reflected in the regression coefficient .754, which accounts for 65.9 percent of the variance. The heritabilities differ significantly in the two sexes, h2 for the males being .263, and for the females .371; this difference seems mainly ascribable to sex-linkage of some of the genetic factors controlling voluntary consumption of alcohol.     

Requirement of JNK2 for scavenger receptor A-mediated foam cell formation in atherogenesis

In vitro studies suggest a role for c-Jun N-terminal kinases (JNKs) in proatherogenic cellular processes. We show that atherosclerosis-prone ApoE-/- mice simultaneously lacking JNK2 (ApoE-/- JNK2-/- mice), but not ApoE-/- JNK1-/- mice, developed less atherosclerosis than do ApoE-/- mice. Pharmacological inhibition of JNK activity efficiently reduced plaque formation. Macrophages lacking JNK2 displayed suppressed foam cell formation caused by defective uptake and degradation of modified lipoproteins and showed increased amounts of the modified lipoprotein-binding and -internalizing scavenger receptor A (SR-A), whose phosphorylation was markedly decreased. Macrophage-restricted deletion of JNK2 was sufficient to decrease atherogenesis. Thus, JNK2-dependent phosphorylation of SR-A promotes uptake of lipids in macrophages, thereby regulating foam cell formation, a critical step in atherogenesis.     

Restricting dislocation movement in transition metal carbides by phase stability tuning

A mechanism to enhance hardness in multilayer coatings is proposed. Using the technologically important hard transition metal carbides as prototypes, although the principle is transferable also to other systems, we demonstrate, from first-principles calculations, that by suitable alloying the energy difference between several competing structures in the transition metal carbides is small or tunable. This creates multiphase/polytypic compounds with a random or controllable layer stacking sequence, systems in which the propagation of dislocations can be strongly suppressed by a large number of interfaces between structures with different glide systems, accordingly allowing the possibility of a greatly enhanced hardness. With modern thin-film technologies, it should therefore be possible to deposit such materials that will express multilayer characteristics with only minor changes in the chemical constitution of the material, which is in contrast to conventional superlattices.