Animal losses due to abortion and malformed offspring during the lambing period 2011/2012 amounted to 50% in ruminants in Europe. A new arthropod-borne virus, called Schmallenberg virus (SBV), was identified as the cause of these losses. Blood samples were obtained from 40 goat flocks and tested for antibodies against SBV by ELISA, with 95% being seropositive. The calculated intra-herd seroprevalence (median 36·7%, min-max 0–93·3%) was smaller than in cattle or sheep flocks. Only 25% of the farmers reported malformations in kids. Statistical analysis revealed a significantly lower risk of goats housed indoors all year-round to be infected by SBV than for goats kept outside day and night. The low intra-herd seroprevalence demonstrates that German goat flocks are still at risk of SBV infection. Therefore, they must be protected during the next lambing seasons by rescheduling the mating period, implementing indoor housing, and continuous treatment with repellents or vaccination.

Over the past century, agricultural landscapes worldwide have increasingly been managed for the primary purpose of producing food, while other diverse ecosystem services potentially available from these landscapes have often been undervalued and diminished. The incorporation of relatively small amounts of perennial vegetation in strategic locations within agricultural landscapes dominated by annual crops—or perennialization—creates an opportunity for enhancing the provision of a wide range of goods and services to society, such as water purification, hydrologic regulation, pollination services, control of pest and pathogen populations, diverse food and fuel products, and greater resilience to climate change and extreme disturbances, while at the same time improving the sustainability of food production. This paper synthesizes the current scientific theory and evidence for the role of perennial plants in balancing conservation with agricultural production, focusing on the Midwestern USA as a model system, while also drawing comparisons with other climatically diverse regions of the world. Particular emphasis is given to identifying promising opportunities for advancement and critical gaps in our knowledge related to purposefully integrating perennial vegetation into agroecosystems as a management tool for maximizing multiple benefits to society.

Let G be a finite group acting on vector spaces V and W and consider a smooth G-equivariant mapping f: V → W. This paper addresses the question of the zero set of f near a zero x with isotropy subgroup G. It is known from results of Bierstone and Field on G-transversality theory that the zero set in a neighbourhood of x is a stratified set. The purpose of this paper is to partially determine the structure of the stratified set near x using only information from the representations V and W. We define an index s(Σ) for isotropy subgroups Σ of G which is the difference of the dimension of the fixed point subspace of Σ in V and W. Our main result states that if V contains a subspace G-isomorphic to W, then for every maximal isotropy subgroup Σ satisfying s(Σ) > s(G), the zero set of f near x contains a smooth manifold of zeros with isotropy subgroup Σ of dimension s(Σ). We also present partial results in the case of group representations V and W which do not satisfy the conditions of our main theorem. The paper contains many examples and raises several questions concerning the computation of zero sets of equivariant maps. These results have application to the bifurcation theory of G-reversible equivariant vector fields.

L'expérimentation, menée au cours d'un cycle annuel sur deux secteurs différents de la rivière Charente à l'aval d'Angoulème, a pour objectif de quantifier le taux de dénitrification pour les besoins d'un modèle hydrologique nitrates. La méthode de blocage du stade final de la réaction de dénitrification à l'acétylène a permis le dosage du protoxyde d'azote à partir de cloches à sédiment et d'un conteneur immergé en pleine eau. Les résultats montrent que, si ce phénomène n'a pas lieu dans la tranche d'eau, la vitesse de dénitrification à l'interface eau-sédiment, facteur K exprimé en mg de nitrates dénitrifiés par m2 par jour, peut être considérée comme constante et indépendante des variations en température, en teneurs en nitrates et oxygène dissous de l'interface. Sur un cycle annuel, en l'absence d'influence marquée des paramètres environnementaux, le taux moyen de dénitrification dans la rivière Charente est de 682 mg de NO3- /m2/ j. La comparaison des mesures obtenues par cette méthode à celles évaluées par le calcul (bilan azoté) montre qu'il est préférable d'estimer le taux de dénitrification par dosage direct plutôt qu'à partir de l'analyse des formes de l'azote (disparition du NO3- ou défaut du bilan).

We calculate the present ice budget for Antarctica from measurements of accumulation minus iceberg calving, run-off and in situ melting beneath the floating ice shelves. The resulting negative mass balance of 469 Gt year−1 differs substantially from other recent estimates but some components are subject to high temporal variability and budget uncertainties of 20–50%. Annual accumulation from an earlier review is adjusted to include the Antarctic Peninsula for a total of 2144 Gt year−1. An iceberg production rate of 2016 Gt year−1 is obtained from the volume of large icebergs calculated from satellite images since 1978, and from the results of an international iceberg census project. Ice-shelf melting of 544 Gt year−1 is derived from physical and geochemical observations of meltwater outflow, glaciological field studies and modeling of the sub-ice ocean circulation. The highest melt rates occur near ice fronts and deep within sub-ice cavities. Run-off from the ice-sheet surface and from beneath the grounded ice is taken to be 53 Gt year−1. Less than half of the negative mass balance need come from the grounded ice to account for the unattributed 0.45 mm year−1 in the IPCC “best estimate” of the recent global sea-level rise.

The primary purpose of the FK5 is to provide an absolute optical reference frame against which to measure the positions and motions of other objects. One of the main tasks of meridian circles is to check and improve that reference frame by repeated observation of the fundamental stars. The meridian circle at Bordeaux, France and the Carlsberg Automatic Meridian Circle (CAMC) at La Palma are carrying out programmes of observation of FK5 stars partly with this aim in view.

The positions from which the systematic differences are derived are the means of at least 10, but normally about 30 (Bordeaux) and 50 (CAMC), independent observations of each FK5 star made in the period 1984–87. The systematic differences are displayed in pairs of 3-dimensional plots, Bordeau–FK5 and CAMC–FK5. The similarities of the corresponding pairs of plots is striking, particularly in declination. This implies that systematic errors exist in the FK5 which reach about in places at the epoch 1986.0.

A new micrometer has been in operation on the Carlsberg Automatic Meridian Circle since May 1988. The zenith mean error for one observation has improved from O.″19 to 0.″14 and the limiting magnitude from 13m.2 to 14m.8. The first meridian observations of Pluto and observations of nine extragalactic objects are briefly discussed.

The Commission deeply regrets the death of our colleague G. Teleki who passed away on February 1987.

After the retirement of T. Dambara, S. Lautsen and W. Gliese and the arrival of C. Turon-Lacarrieu as a new member, the membership of our commission is 142.