Iron partitioning in Earth's mantle: toward a deep lower mantle discontinuity

We measured the spin state of iron in ferropericlase (Mg0.83Fe0.17)O at high pressure and found a high-spin to low-spin transition occurring in the 60- to 70-gigapascal pressure range, corresponding to depths of 2000 kilometers in Earth's lower mantle. This transition implies that the partition coefficient of iron between ferropericlase and magnesium silicate perovskite, the two main constituents of the lower mantle, may increase by several orders of magnitude, depleting the perovskite phase of its iron. The lower mantle may then be composed of two different layers. The upper layer would consist of a phase mixture with about equal partitioning of iron between magnesium silicate perovskite and ferropericlase, whereas the lower layer would consist of almost iron-free perovskite and iron-rich ferropericlase. This stratification is likely to have profound implications for the transport properties of Earth's lowermost mantle.     

Global mapping of the yeast genetic interaction network

A genetic interaction network containing approximately 1000 genes and approximately 4000 interactions was mapped by crossing mutations in 132 different query genes into a set of approximately 4700 viable gene yeast deletion mutants and scoring the double mutant progeny for fitness defects. Network connectivity was predictive of function because interactions often occurred among functionally related genes, and similar patterns of interactions tended to identify components of the same pathway. The genetic network exhibited dense local neighborhoods; therefore, the position of a gene on a partially mapped network is predictive of other genetic interactions. Because digenic interactions are common in yeast, similar networks may underlie the complex genetics associated with inherited phenotypes in other organisms.     

Action of FAO in the control of foot and mouth disease

This paper describes the role played by FAO in the control of foot and mouth disease. Since 1954 the FAO European Commission for the control of foot-and-mouth disease co-ordinated the regional programme for eradication of FMD in Europe. One of the major achievements of the Commission has been to prevent the introduction and spread of exotic strains of foot and mouth disease into Europe through the Balkans. FAO also supports the activities of the Foot-and-Mouth Disease World Reference Laboratory located in the Institute of Animal Health, Pirbright, UK.

The Infectious Diseases/EMPRES Group of the Animal Health Service, Animal Production and Health Division of FAO, promotes a global approach to the control and eradication of transboundary animal diseases over the world. For foot and mouth disease, the strategy is based on co-ordinated regional programmes. For FAO, no sustainable progress can be achieved in FMD control over the world without addressing and supporting the control of the disease in endemic countries.

Résumé

L'article décrit le rôle joué par la FAO dans la lutte contre la fièvre aphteuse. Depuis 1954, la Commission Européenne de Lutte contre la fièvre aphteuse de la FAO coordonne le programme régional d’éradication en Europe. Un des succès majeur de cette Commission a été de prévenir l'introduction et la diffusion des souches exotiques de virus de la fièvre aphteuse à travers les Balkans. La FAO soutient également les activités du Laboratoire Mondial de référence pour la fièvre aphteuse qui se situe à l'Institut pour la Santé Animale de Pirbright au Royaume Uni.

Le Groupe Maladies Infectieuses/EMPRES du Service de Santé Animale au sein de la Division Production et Santé Animale de la FAO défend une approche globale de lutte et d’éradication des maladies transfrontalières à travers le monde. Pour la fièvre aphteuse, la stratégie est basée sur une approche régionale coordonnée. Pour la FAO, aucun progres significatif durable ne peut être obtenu dans la lutte contre la fièvre aphteuse à travers le monde sans que la question de la lutte dans les pays où la maladie est endémique ne soit prise en compte et soutenue.     

Decomposition and nutrient release pattern of agro-processing by-products biodegraded by fly larvae in Acrisols

ABSTRACT

Fly larvae are increasingly being promoted as animal feed and their production on agro-processing by-products generates a high amount of residues. Understanding the decomposition and nutrients release pattern in the soil of these residues is of importance to evaluate their quality as soil amendment. A litter bag experiment was carried out over 75 days in southern Benin with corn bran, a mixture of soybean bran and corn bran and a mixture of soybean bran and corn hull, all biodegraded in advance by larvae of Musca domestica and Hermetia illucens. Bags with 200 g dry matter of each residue were buried in the soil. The first order equation of mono-component model Y_t = Y₀×e^?kt was suitable and described well the decomposition and mineralization pattern of the residues. The residues decomposed quickly and released nutrients readily into the soil. The mass remaining at the end of the decomposition process ranged between 38% and 42% of the initial weight. The half-life of the organic carbon in the residues ranged between 50 and 58 days. Organic nitrogen mineralized fast, with rates ranging between 0.007 and 0.011 day^?1. These organic residues can be used as soil amendments to improve crop productivity in an Acrisol.     

Influence of squid extracts on the triggering of secondary vitellogenesis in Penaeus vannamei

A series of five experiments were carried out to find an alternative to eyestalk ablation for inducing and controlling vitellogenesis in penaeid shrimps. Several extracts from squid were tested as supplements to a basal diet. Polar components of hydro-alcohol (ethanol/dicloromethane/water, 2:2:1:8) soluble and lipid squid fractions (Bligh & Dyer), when incorporated in formulated feed at low doses, trigger secondary vitellogenesis in 15–35 g female Penaeus vannamei , showing maturations of the same order of magnitude as the eyestalk-ablated controls. Achievement of vitellogenesis was estimated by a homologous ELISA-vitellogenin test. Even though the nature of the active molecules was not completely elucidated, the results obtained indicate that they may probably be steroid-like molecules of cephalopods, acting in a heterologous way.     

Are precision agriculture tools and methods relevant at the whole-vineyard scale?

Precision viticulture (PV) has been mainly applied at the field level, for which the ability of high resolution data to match within-field variability has been already shown. However, the interest of PV for grape growers would be greater if its principles could also apply at a larger scale, as most growers still focus their management on a multi-field scale, not considering each field as an isolated unit. The aim of this study was to analyse whether it is possible and relevant to use PV tools to define meaningful management zones at the whole-vineyard scale. The study was carried out on a 90-ha vineyard made of 27 contiguous fields. The spatial variability of vine vigour, estimated with the Normalized Difference Vegetation Index (NDVI), was analysed at within-field and whole-vineyard scales. The spatial variability of the vigour was significant and spatially organized whatever the considered scale. Besides, vineyard spatial variability was characterised using information on environmental factors (soil apparent conductivity and elevation) and vine response (yield, vigour and grape composition). At both scales, NDVI and measured environmental factors were used to establish a three-level classification, whose agronomic significance was tested comparing the vine response observed for each class. The analysis of high resolution information allowed the definition of classes with agronomic and oenological implications, although there was not a straightforward correspondence between the classes defined and quality. Analysing the variability at the whole-vineyard scale highlighted a trend of spatial variation associated to elevation that was hardly visible at the within-field level.     

Epidemiology,molecular virology and diagnostics of Schmallenberg virus,an emerging orthobunyavirus in Europe

After the unexpected emergence of Bluetongue virus serotype 8 (BTV-8) in northern Europe in 2006, another arbovirus, Schmallenberg virus (SBV), emerged in Europe in 2011 causing a new economically important disease in ruminants. The virus, belonging to the Orthobunyavirus genus in the Bunyaviridae family, was first detected in Germany, in The Netherlands and in Belgium in 2011 and soon after in the United Kingdom, France, Italy, Luxembourg, Spain, Denmark and Switzerland. This review describes the current knowledge on the emergence, epidemiology, clinical signs, molecular virology and diagnosis of SBV infection.