What is a model, why people don't trust them, and why they should

It is easier to make one�s way in the world if one has some sort of expectation of the world�s future behaviour. Even when facing a very complex problem, we are rarely in a state of full ignorance: some expectations of system behaviour and the level of risk arising from uncertainty are usually available and it is on the basis of these expectations that most decisions are taken. Humans use models, which are mental or formal representations of reality, to generate these expectations, employing an ability that is shared more or less by all forms of life. Whether it is a tree responding to shortening day length by dropping its leaves and preparing its metabolism for the winter ahead or a naked Pleistocene ape storing food in advance of winter for the same reasons, both are using models. This view leads to two outcomes. The first is that predictions, seen as an expectation of ranges of future behaviours, are not just desirable, but necessary for decision-making. The often-asked question �do models provide reliable predictions?� then shifts to �given a certain problem, what type of models provide the most useful and reliable prediction?� The second outcome is that modelling is no longer a scientist�s activity but is instead a social process. Different types of models can be employed to ensure that all available information is included in model building and that model results are understood, trusted and acted upon

Ontogeny, expression and molecular characterization of the A blood group system of the chicken

A monoclonal antibody (ISU-cA) was characterized that recognized certain alloantigens of the chicken A blood group locus. It was specific for A[superscript]3, A[superscript]4 and A[superscript]8 antigens, but not for A[superscript]2 or A[superscript]5 antigens. Specificity of ISU-cA for A blood group antigens was demonstrated by serologic analyses, genetic crosses, competitive binding between ISU-cA and blood group A-specific alloantisera and immunoprecipitation of identical molecules with ISU-cA and alloantisera. Blood group A antigens were detectable on erythrocytes from 3 days of incubation and gradually increased in expression until adulthood. Antigen expression of heterozygotes was intermediate in level between those of each homozygous parent confirming the co-dominant expression of blood group antigens. Flow cytometric analyses showed that the increase in antigen expression with age was due to an increase in the level of A antigen expression on individual erythrocytes. The SDS-PAGE showed relative molecular weights of 53 Kd for A[superscript]2 and 54.5 Kd for A[superscript]4. The non-reduced molecular weight for both antigens of 44.5 Kd suggested the presence of intra-chain disulfide bonds. Two-dimensional gel electrophoresis indicated that A blood group antigens consist of a single, probably glycosylated, molecule with pI of approximately 6.5

Plug-In Electric Vehicles: A Case Study of Seven Markets

At the current stage of plug-in electric vehicle (PEV) market development, sales rates vary dramatically across different countries and regions. For policy-makers and other stakeholders it is useful to understand the major social, economic, and policy drivers of vehicle adoption. This paper provides insights into the developing PEV markets in Norway, Netherlands, California, United States, France, Japan, and Germany. This is accomplished by applying a Technological Innovation System (TIS) approach that systematically identifies the role of different factors in promulgating new markets. Our comparison between markets shows that in all studied regions, sales of PEVs are supported through various types of government incentives, government resources, and other legitimation activities. However, regions with relatively strong PEV markets have a greater focus on market formation activities and relatively higher costs savings associated with operating an electric vehicle as compared to a conventional vehicle. To determine whether these factors are the primary determinants of PEV market shares, further research should be undertaken that also incorporates analysis related to the presence and government support for entrepreneurial activities related to electric vehicle innovation

How fast is fisheries-induced evolution? : Quantitative analysis of modelling and empirical studies

Peer reviewe

Nutritional Analysis of Whole Green Crab, Carcinus maenas, for Application as a Forage Fish Replacement in Agrifeeds

Nutritional composition of a composite sample of whole green crabs, Carcinus maenas (L.), was undertaken to evaluate efficacy as a forage fish replacement for seafood-meal manufacture. Whole green crabs sampled from New Hampshire waters were ground together and analyzed for proximate profile (moisture, lipid, protein, fiber, and ash), fatty acid profile, amino acid profile, mineral composition, and mercury content. Green crab mince contained 16.55 ± 0.29% ash, 12.27 ± 0.25% protein, and 0.21 ± 0.07% lipid, and comprised all amino acids essential for chickens and most species of fish. Fatty acid composition of ground green crab was 67.98% unsaturated, and 23.29% saturated, and was richer in eicosapentaenoic acid (EPA) than docosahexaenoic acid (DHA). Levels of mercury in green crab mince were below testable limits. The nutritional profile of green crab mince was evaluated relative to the nutritional profile of menhaden from the literature, and possible agrifeed applications for whole green crab were considered. Green crab showed great potential as a forage fish replacer in seafood-meal applications for chickens and ash tolerant species of fish

How long can fisheries management delay action in response to ecosystem and climate change?

Sustainable management of fisheries is often compromised by management delaying implementation of regulations that reduce harvest, in order to maintain higher catches in the short term. Decreases or increases in fish population growth rate driven by environmental change, including ecosystem and climate change, affect the harvest that can be taken sustainably. If not acted on rapidly, environmental change could result in unsustainable fishing or missed opportunity for higher catches. Using simulation models of harvested fish populations influenced by environmental change, we explore how long fisheries managers can afford to wait before changing harvest regulations in response to changes in population growth. If environmental change causes population declines, delays greater than five years increase the probability of population collapse. Species with fast and highly variable population growth rates are more susceptible to collapse under delays and should be a priority for revised management where delays occur. Generally, the long-term cost of delay, in terms of lost fishing opportunity, exceeds the short-term benefits of overfishing. Lowering harvest limits and monitoring for environmental change can alleviate the impact of delays; however, these measures may be more costly than reducing delays. We recommend that management systems that allow rapid responses to population growth changes be enacted for fisheries management to adapt to ecosystem and climate change