Evolution of Chemical Composition and Microbial Activity during Storage of Compost-Based Mixes

? Horticultural substrates composed of equal parts of peat and compost (v/v) were stored for a period of 24 weeks. The chemical properties and the microbial activity were determined periodically for a wet mix (55% moisture), a dry mix (25% moisture) and a wet mix amended with feather meal. Results showed that electrical conductivity and major nutrients increased with the length of the storage period whereas pH, ammonium and minor elements with the exception of manganese were strongly reduced. The pH and the chemical composition of the dry mix were not affected during storage. Feather meal actively stimulated the microorganisms within few weeks and raised electrical conductivity and nitrates at the end of storage. It was concluded that changes which occurred during storage were related to the microbial activity.     

BIOINSECTICIDES AS FUTURE MAINSTREAM PEST CONTROL AGENTS: OPPORTUNITIES AND CHALLENGES

•Wide use of botanical insecticides is limited by the availability of certain plants. •Studies are needed to improve RNAi efficiency and to assess their safety risk. •Microbial insecticides are promising, but they only control a narrow range of pests. •Multitarget approach should be a promising strategy in future pest control. •Nanoformulation could enhance stability and control the release of bioinsecticides. Bioinsecticides are naturally-occurring substances from different sources that control insect pests. Ideal bioinsecticides should have low toxicity to non-target organisms. They should also be easily degraded in sewage treatment works and natural environments, highly effective in small quantities and affect target pests only. Public concerns about possible side-effects of synthetic pesticides have accelerated bioinsecticide research and development. However, to develop bioinsecticides into mainstream products, their high production costs, short shelf-life and often uncertain modes of action need to be considered. This review summarizes current progress on bioinsecticides which are categorized as biochemical insecticides and their derivatives, plant-incorporated protectants, and microbial bioinsecticides. The current constraints that prevent bioinsecticides from being widely used are discussed and future research directions are proposed.     

Supporting strategic thinking of smallholder dairy farmers using a whole farm simulation tool

This article investigates how a one-to-one support process based on the use of a whole dairy farm simulation tool helps both farmers to reflect on their production strategies and researchers to better understand the farmers’ contexts of action and decision. The support process consists of a minimum of four discussion sessions with the farmer: designing the Initial Scenario and formulating a diagnosis, building and simulating the Project Scenario corresponding to the objective targeted by the farmer, building and comparing alternative scenarios proposed both by the farmer and the researcher, and evaluating the process with the farmer. The approach was tested with six smallholder farmers in Brazil. It is illustrated with the example of one farmer who aimed to develop his milk production by more than doubling his herd size on the same cultivated area. Two other examples illustrate the diversity of issues addressed with this approach. The first estimates the sensitivity of economic results to price variations of milk and concentrates. The second compares two scenarios in terms of forage supply autonomy. The discussion assesses the outcomes of the approach for farmers in terms of response to their specific issues and of knowledge acquired. The research outputs are discussed in terms of the value and limits of using simulation tools within both participatory action research and advisory processes.     

Potential Chemopreventive Activity of a New Macrolide Antibiotic from a Marine-Derived Micromonospora sp

Agents capable of inducing phase II enzymes such as quinone reductase 1 (QR1) are known to have the potential of mediating cancer chemopreventive activity. As part of a program to discover novel phase II enzyme-inducing molecules, we identified a marine-derived actinomycete strain (CNJ-878) that exhibited activity with cultured Hepa 1c1c7 cells. Based on this activity, a new macrolide, juvenimicin C (1), as well as 5-O-α-l-rhamnosyltylactone (2), were isolated from the culture broth of a Micromonospora sp. Compound 1 enhanced QR1 enzyme activity and glutathione levels by two-fold with CD values of 10.1 and 27.7 μM, respectively. In addition, glutathione reductase and glutathione peroxidase activities were elevated. This is the first reported member of the macrolide class of antibiotics found to mediate these responses.     

Marker assisted recurrent selection for cumulating QTLs for bread-making related traits

We used a computer program to manage marker data in a recombinantinbred line population. The objective was to select pairs of inbred lines tobe intercrossed, in order to cumulate all favourable alleles, either withadditive effects or with interactive effects. The population size required tohave 95% chance of obtaining the best line from a given cross iscomputed, taking into account the number of QTLs and the probability thatno recombination event occurs in any QTL confidence intervals. It is shownthat the accuracy of QTL location greatly affects selection efficiency andthat a recurrent selection scheme is highly preferable for pyramiding manyQTLs. Dough strength (W) was chosen to illustrate the use of this method.In a population of 187 DH lines from the cross Courtot × Chinese Spring,W was found to be controlled by 8 additive QTLs and two pairs ofinteractive QTLs. None of the 187 DH lines possess all favourable allelesor combination of alleles. The best possible line could be produced by asingle cycle of crossing followed by line extraction, but several thousandlines needed to be produced to achieve this goal. Alternatively, a recurrentcrossing scheme allows to obtain the best line in two generations, andrequires less than 150 lines per cycle.     

Association of two newly recognized herpesviruses with interstitial pneumonia in donkeys (Equus asinus).

Over a period of 6 years, antemortem and postmortem examinations were performed on a number of donkeys suffering from respiratory disease. For many cases, initial diagnostic efforts failed to identify an etiology consistent with the pathologic findings. However, retrospective examination of these cases using consensus primer polymerase chain reaction, designed to recognize herpesviruses from all 3 subfamilies of the Herpesviridae, amplified a fragment of the highly conserved herpesvirus DNA polymerase gene from a number of these animals. Two novel herpesviruses, herein designated asinine herpesvirus 4 (AHV4) and asinine herpesvirus 5 (AHV5), were consistently detected in lung tissue from donkeys in which the histopathology was characterized by interstitial pneumonia and marked syncytial cell formation but not in lung tissue from donkeys with evidence of bacterial or verminous pneumonia. Nucleotide sequence and phylogenetic analysis places these new viruses within the Gammaherpesvirinae subfamily and indicates that they are most closely related to the recently identified zebra herpesvirus and wildass herpesvirus as well as equine herpesviruses 2 and 5.     

Mast cell tumors in the dog.

The most common skin tumor in dogs is the mast cell tumor (MCT), with an incidence of close to 20% in the canine population. MCTs range from relatively benign to extremely aggressive, leading to metastasis and eventual death from systemic disease. Although surgical removal with or without radiation therapy may cure most patients with low-grade MCTs, there are no effective treatments for dogs with aggressive high-grade MCTs. This article reviews the current understanding of MCT biology with regard to diagnosis, staging, identification of prognostic indicators, and appropriate treatment planning.