Stock assessment in brown shrimp (Crangon crangon) part 1: Investigation of possible methods

Het Ministerie van LNV, de gezamenlijke Producentenorganisaties voor de garnalenvisserij in Nederland, en de natuurorganisaties Stichting de Noordzee en de Waddenvereniging hebben het belang onderschreven van een gezamenlijk traject naar een verduurzaming van de garnalenvisserij en het verkrijgen van een MSC (Marine Stewardship Councel) certificering voor de garnalenvisserij. Om voor een MSC label in aanmerking te komen moet er aangetoond worden dat de gewone garnaal, Crangon crangon, niet overbevist wordt. Momenteel wordt de garnalen visserij niet beheerd en is er geen officiële bestandschatting. Wel worden er door de ICES crangon werkgroep (WGCRAN, ICES working Group on crangon fisheries and life history) op een beschrijvende manier de fluctuaties in dichtheden van de gewone garnaal bijgehouden. Het is echter wenselijk om tot een meer kwantitatieve bestandschatting te komen

Direct mail selection by joint modeling of the probability and quantity of response

Operations such as integration or modularization of databases can be considered as operations on database universes. This paper describes some operations on database universes. Formally, a database universe is a special kind of table. It turns out that various operations on tables constitute interesting operations on database universes as well.

Fock representations of the Lie superalgebra q(n+1)

For the Lie superalgebra $q(n+1)$ a description is given in terms of creation and annihilation operators, in such a way that the defining relations of $q(n+1)$ are determined by quadratic and triple supercommutation relations of these operators. Fock space representations $V_p$ of $q(n+1)$ are defined by means of these creation and annihilation operators. These new representations are introduced as quotient modules of some induced module of $q(n+1)$. The representations $V_p$ are not graded, but they possess a number of properties that are of importance for physical applications. For $p$ a positive integer, these representations $V_p$ are finite-dimensional, with a unique highest weight (of multiplicity 1). The Hermitian form that is consistent with the natural adjoint operation on $q(n+1)$ is shown to be positive definite on $V_p$. For $q(2)$ these representations are ``dispin''. For the general case of $q(n+1)$, many structural properties of $V_p$ are derived.Comment: 24 pages, LaTeX file, small corrections done; to appear in J. Phys. A: Math. Ge

What research we no longer need in neurodegenerative disease at the end of life : The case of research in dementia

A complete silence. That was what we got back from the European experts who had been energetically discussing research priorities in palliative care in neurodegenerative disease (ND) until a short while ago.1 The chair, an entertaining professor with good manners, must have felt the unease and quickly refocused the group to their task. But, wasn’t this the best question of all day? What research we no longer need? As scientists able to consider different perspectives, shouldn’t we have some idea of what research is, by contrast, no longer necessary? Palliative care research and research with people who have ND and are at the end of their life is, by definition, difficult. Making choices is a sensitive issue, but funds are limited. Therefore, we take a counterpoint to the research agenda recently reported by European Union (EU) Joint Programme – Neurodegenerative Disease Research (JPND),1 and consider whether there are studies we no longer need or are low priority, taking the example of dementiaPeer reviewedFinal Accepted Versio

Observational cosmology using characteristic numerical relativity

The characteristic formalism in numerical relativity, which has been developed to study gravitational waves, and the observer metric approach in observational cosmology both make use of coordinate systems based on null cones. In this paper, these coordinate systems are compared and it is then demonstrated how characteristic numerical relativity can be used to investigate problems in observational cosmology. In a numerical experiment using the characteristic formalism, it is shown how the historical evolution of a LTB universe compares to that of the $\Lambda$CDM model given identical observational data on a local observer's past null cone. It is demonstrated that, at an earlier epoch of the LTB model, the observational data would not be consistent with that of the $\Lambda$CDM model