Below ground interactions for sustainable cropping systems.

Key aspects of cropping systems are described in terms of their impacts on soil, water and air resources. The importance of microbial symbiotic relations with crop plants are briefly considered in the context of nutrient resource use efficiency and the resilience of plants to biotic and abiotic stress. It is argued that cropping systems need to include crops with fibrous root systems and legumes in the rotation to ensure sustainable use of resources. Three series of experiments are discussed that considered how the efficacy of rhizobia and indigenous arbuscular mycorrhizal fungi could be enhanced in sustainable cropping systems. Evidence is presented to demonstrate that there are potential benefits to crop production from improved management of soil resources through the adoption of reduced tillage practices coupled with suitable crop rotation and weed control

Efeito da cobertura do solo com manta Ecoblanket no desenvolvimento das infestantes em pomares de pessegueiros na região da beira interior

Efeito da cobertura do solo com manta Ecoblanket no desenvolvimento das infestantes em pomares de pessegueiros na região da beira interiorinfo:eu-repo/semantics/publishedVersio

Engineered Picornavirus VPg-RNA Substrates: Analysis of a Tyrosyl-RNA Phosphodiesterase Activity

Using poliovirus, the prototypic member of Picornaviridae, we have further characterized a host cell enzymatic activity found in uninfected cells, termed “unlinkase,” that recognizes and cleaves the unique 5′ tyrosyl-RNA phosphodiester bond found at the 5′ end of picornavirus virion RNAs. This bond connects VPg, a viral-encoded protein primer essential for RNA replication, to the viral RNA; it is cleaved from virion RNA prior to its engaging in protein synthesis as mRNA. Due to VPg retention on nascent RNA strands and replication templates, but not on viral mRNA, we hypothesize that picornaviruses utilize unlinkase activity as a means of controlling the ratio of viral RNAs that are translated versus those that either serve as RNA replication templates or are encapsidated. To test our hypothesis and further characterize this enzyme, we have developed a novel assay to detect unlinkase activity. We demonstrate that unlinkase activity can be detected using this assay, that this unique activity remains unchanged over the course of a poliovirus infection in HeLa cells, and that unlinkase activity is unaffected by the presence of exogenous VPg or anti-VPg antibodies. Furthermore, we have determined that unlinkase recognizes and cleaves a human rhinovirus-poliovirus chimeric substrate with the same efficiency as the poliovirus substrate

Language of Lullabies: The Russification and De-Russification of the Baltic States

This article argues that the laws for promotion of the national languages are a legitimate means for the Baltic states to establish their cultural independence from Russia and the former Soviet Union

Heterogeneity of protected crop colonization by beneficial insects: role of crop management and landscape context

Enhancing insect pest control by their natural enemies is considered as a promising crop protection strategy in organic vegetable production systems. In Mediterranean areas, native natural enemies such as mirid bugs (Heteroptera: Miridae) settle spontaneously in protected vegetable crops and can play an important rolefor pest regulation, which remains however very heterogeneous from field to field and hardly predictable. The present study is part of the project REGABRI, which aims at identifying key factors of colonization of organic and conventional protected tomato crops by mirid bugs in Roussillon area. A first survey in 2010-2011 on 34 crops showed that mirids abundances in crops vary according to management practices and landscape features in the crops surroundings (100m to 200m). A second survey in 2012 made it possible to identify uncultivated or cultivated elements in the crops surroundings, that might enhance (source habitats) or on the contrary reduce (dilution and sink effects) tomato crops colonization by mirids. These results showed that a systemic approach, considering the field, the cropping systems as well as the landscape scale, is needed to optimize conservation biological control on protected vegetable systems

Disentangling higher trophic level interactions in the cabbage aphid food web using high-throughput DNA sequencing

The lack of understanding of complex food-web interactions has been a major gap in the history of biological control. In particular, a better understanding of the functioning of pest food-webs and how they vary between native and invaded geographical ranges is of prime interest for biological control research and associated integrated pest management. Technical limitations associated with the deciphering of complex food-webs can now be largely overcome by the use of high throughput DNA sequencing techniques such as Illumina MiSeq. We tested the efficiency of this next generation sequencing technology in a metabarcoding approach, to study aphid food-webs using the cabbage aphid as model. We compared the variations in structure and composition of aphid food-webs in the species' native range (United Kingdom, UK) and in an invaded range (New Zealand, NZ). We showed that Illumina MiSeq is a well suited technology to study complex aphid food-webs from aphid mummies. We found an unexpectedly high top down pressure in the NZ cabbage aphid food-web, which coupled to a large ratio of consumer species / prey species and a lack of potential inter-specific competition between primary parasitoids, could cause the NZ food-web to be more vulnerable than the UK one. This study also reports for the first time the occurrence of a new hyperparasitoid species in NZ, as well as new associations between hyperparasitoids parasitoids and the cabbage aphid in this country. We conclude that the complexity of aphid food-webs in agricultural systems could often be underestimated, particularly at higher trophic levels; and that the use of high throughput DNA sequencing tools, could largely help to overcome this impediment