A hierarchy of compatibility and comeasurability levels in quantum logics with unique conditional probabilities

In the quantum mechanical Hilbert space formalism, the probabilistic interpretation is a later ad-hoc add-on, more or less enforced by the experimental evidence, but not motivated by the mathematical model itself. A model involving a clear probabilistic interpretation from the very beginning is provided by the quantum logics with unique conditional probabilities. It includes the projection lattices in von Neumann algebras and here probability conditionalization becomes identical with the state transition of the Lueders - von Neumann measurement process. This motivates the definition of a hierarchy of five compatibility and comeasurability levels in the abstract setting of the quantum logics with unique conditional probabilities. Their meanings are: the absence of quantum interference or influence, the existence of a joint distribution, simultaneous measurability, and the independence of the final state after two successive measurements from the sequential order of these two measurements. A further level means that two elements of the quantum logic (events) belong to the same Boolean subalgebra. In the general case, the five compatibility and comeasurability levels appear to differ, but they all coincide in the common Hilbert space formalism of quantum mechanics, in von Neumann algebras, and in some other cases.Comment: 12 page

Report on the Diet of the Blue Whiting in the Barents Sea in the Summer 2005 and in the Winters of 2002 and 2006

We analyzed stomach content of blue whiting in the Barents Sea in February-March 2002 and 2006, and in August-September 2005. Krill was the most important prey for blue whiting in the Barents Sea, and constituted about 90% of diet in winter and 50% in summer. Blue whiting also fed on amphipods and fish, including blue whiting. Copepods, an important group of prey for blue whiting in the Norwegian Sea, was unimportant in the diet in the Barents Sea. NORSK SAMMENDRAG: Vi undersøkte dietten til kolmule i Barentshavet i februar-mars 2002 og 2006, og i august og september 2005. Krill var det viktigste byttet til kolmula i Barentshavet, og utgjorde ca 90% av diett om vinteren og ca 50% om sommeren. Kolmula spiste også amfipoder og fisk, inkludert kolmule. Hoppekreps som er viktig for kolmula i Norskehavet, utgjorde en ubetydelig andel av dietten

Maturation Trends Suggestive of Rapid Evolution Preceded the Collapse of Northern Cod

Northern cod, comprising populations of Atlantic cod (Gadus morhua) off southern Labrador and eastern Newfoundland, supported major fisheries for hundreds of years. But in the late 1980s and early 1990s, northern cod underwent one of the worst collapses in the history of fisheries. The Canadian government closed the directed fishing for northern cod in July 1992, but even after a decade-long offshore moratorium, population sizes remain historically low. Here we show that, up until the moratorium, the life history of northern cod continually shifted towards maturation at earlier ages and smaller sizes. Because confounding effects of mortality changes and growth-mediated phenotypic plasticity are accounted for in our analyses, this finding strongly suggests fisheries-induced evolution of maturation patterns in the direction predicted by theory. We propose that fisheries managers could use the method described here as a tool to provide warning signals about changes in life history before more overt evidence of population decline becomes manifest

Eight decades of adaptive changes in herring reproductive investment: the joint effect of environment and exploitation

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Integral functions of marine vertebrates in the ocean carbon cycle and climate change mitigation

In the last decade, the ocean has absorbed a quarter of the Earth’s greenhouse gas emissions through the carbon (C) cycle, a naturally occurring process. Aspects of the ocean C cycle are now being incorporated into climate change mitigation and adaptation plans. Currently, too little is known about marine vertebrate C functions for their inclusion in policies. Fortunately, marine vertebrate biology, behavior, and ecology through the lens of C and nutrient cycling and flux is an emerging area of research that is rich in existing data. This review uses literature and trusted data sources to describe marine vertebrate C interactions, provides quantification where possible, and highlights knowledge gaps. Implications of better understanding the integral functions of marine vertebrates in the ocean C cycle include the need for consideration of these functions both in policies on nature-based climate change mitigation and adaptation, and in management of marine vertebrate populations.Thank you to the anonymous reviewers whose insightful suggestions greatly improved the manuscript. Thank you to Thomas Eikeland Fiska˚ at the University of Agder for his work on the conceptual figures and to Dr. Marion Martin and Dr. Susanna Huneide Thorbjørnsen for helpful discussions throughout the preparation of the manuscript. Thanks also to Corallie Hunt for comments and advice during the early stages of the manuscript preparation. E.M.O. received support from the Marine Science program within the Research Council of Norway, grant no. 294926 (CODSIZE). H.C.P. was supported by Fulbright Norway, GRID-Arendal, and the University of Alaska Southeast.Ye

The effects of parasitism and body length on positioning within wild fish shoals

The influence of body length and parasitism on the positioning behaviour of individuals in wild fish shoals was investigated by a novel means of capturing entire shoals of the banded killifish (Fundulus diaphanus, Lesueur) using a grid-net that maintained the two-dimensional positions of individuals within shoals. Fish in the front section of a shoal were larger than those in the rear. Individuals parasitized by the digenean trematode (Crassiphiala bulboglossa, Haitsma) showed a tendency to occupy the front of shoals. Parasitized fish were also found more in peripheral positions than central ones in a significant number of shoals. Shoal geometry was affected by the overall parasite prevalence of shoal members; shoals with high parasite prevalence displayed increasingly phallanx-like shoal formations, whereas shoals with low prevalence were more elliptical. There was no relationship between body length and parasite abundance or prevalence in the fish population which suggests body length and parasite status are independent predictors of positioning behaviour. Solitary individuals found outside shoals were both more likely to be parasitized and had higher parasite abundance than individuals engaged in shoaling. Differences in the shoaling behaviour of parasitized and unparasitized fish are discussed in the context of the adaptive manipulation hypothesis

Contrasting evolutionary demography induced by fishing: the role of adaptive phenotypic plasticity

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