New notes on the distribution of <i>Ensis directus</i> (Conrad, 1843) in western Europe

Recently, an overview (Severijns, 2002) of the distribution of Ensis directus (Conrad, 1843) in Europe since its introduction near Hamburg in 1978 (von Cose1 et al., 1982) till the year 2000 was given. The southern most location where the species was found up to 2000 was Merville-Franceville-Plage, on the east bank of the mouth of the river Ome, near Caen (Fig. 1 ). In this paper new observations on the distribution of E. directus in France, which were carried out over the last three years, are presented and discussed. It follows that E. directus has now reached the region of St. Vaast-La-Hougue

Determination of |Vud| from nuclear mirror transitions

The Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix has traditionally been determined from the analysis of data in nuclear superallowed 0+ to 0+ transitions, neutron decay and pion beta decay. We show here that this element can independently be determined from nuclear mirror transitions. The extracted value, |Vud| = 0.9719 +- 0.0017, is at 1.2 combined standard deviations from the value obtained in superallowed 0+ to 0+ transitions and has a similar precision than the value obtained from neutron decay experiments. We discuss some prospects to improve its precision through experiments in nuclear mirror transitions.Comment: 4 pages, 2 figure

Comment to "Observation of the neutron radiative decay" by R.U. Khafizov et al., published in JETP Letters 83 (2006) 5 (Pis'ma v ZhETF 83 (2006) 7)

The commented manuscript was submitted for publication without informing at least four of the other authors, viz. N. Severijns, O. Zimmer, H.-F. Wirth and D. Rich. This violates our rights as collaborators. The analysis presented and the manuscript itself have not been discussed and have also not been approved by the entire collaboration prior to submission. Besides this formal incorrectness, we also criticise the content of the paper

Tests of the standard electroweak model in beta decay

We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are interpreted in the framework of phenomenological model-independent descriptions of nuclear beta decay as well as in some specific extensions of the standard model. The values of the standard couplings and the constraints on the exotic couplings of the general beta decay Hamiltonian are updated. For the ratio between the axial and the vector couplings we obtain C_A/C_V = -1.26992(69) under the standard model assumptions. Particular attention is devoted to the discussion of the sensitivity and complementarity of different precision experiments in direct beta decay. The prospects and the impact of recent developments of precision tools and of high intensity low energy beams are also addressed

Slak-in-Du project. Inventarisatie van de mollusken in de duingebieden langs de Belgische Kust - 2012 Oostkust

The Slak-in-Du (Snails in the Dunes) project aims at establishing, over a period of about six years, a new inventory of the molluscan fauna in the Belgian coastal dunes area. In the first year of the project the eastern part of the Belgian coast was investigated, i.e. the region east of the harbor of Zeebrugge. About 20 persons have contributed in one way or another. The results are very satisfactorily: A total of 30 species of land snails (among which 5 species of slugs), but also 6 species of freshwater molluscs and 5 species preferring brackish waters were observed. More than half of the species of land snails observed are reported for the first time since 1950 or even for the first time ever for the UTM (Universal Transverse Mercator) 10 x 10 km squares that were investigated, i.e. ES18, ES28 en ES29. The most important of these is undoubtedly Vertigo angustior, a protected species which was found for the first time in more than 50 years at the eastern part of the Belgian coast and for the first time ever in the nature reserve “Het Zwin”. Four other species are reported for the first time in the region that was investigated, i.e. Zonitoides nitidus, Cochlicella acuta, Cernuella cisalpina (= C. jonica) and Alinda biplicata biplicata. The latter had, moreover, never been observed before in the Belgian coastal area. Five species were found rather frequently, i.e. Monacha cantiana, Candidula intersecta, Cernuella virgata, Theba pisana and Cepaea nemoralis. The data that were collected further clearly show that Cochlicella acuta and Theba pisana pisana have by now spread along the entire Belgian coast. On the other hand, several species that are thought to be in decline at the Belgian coast, i.e. Monacha cartusiana, Helicella itala itala, Candidula gigaxii, and Candidula unifasciata unifasciata, have not been observed at all. As only one specimen of Cernuella aginnica was found, also this species is probably in decline. Since only few freshwater habitats occurred in the areas that were investigated in 2012 only a limited number of freshwater species is reported here. Finally, as to brackish water snails, the very rare species Limapontia depressa and Assiminea grayana were found in the “Bay of Heist”, while one specimen of Ecrobia ventrosa was observed alive in the nature reserve “Het Zwin”