The effect of diet on ontogenic development of the digestive tract in juvenile reared long snout seahorse Hippocampus guttulatus

Ontogenetic development of the digestive tract and associated organs in long snout seahorse Hippocampus guttulatus juveniles was morphologically and histologically examined from the time of release from the male’s pouch until 72 h after the first meal. When released from the male’s pouch, juvenile seahorses are small adult replicates. This means that unlike other teleost fish larvae, the first developmental phase has already taken place, and juveniles are morphologically prepared and able to feed on live prey immediately following parturition. At this stage, the buccopharynx, oesophagus, and intestine already appear to be fully developed. The intestine is divided into the midgut and hindgut by an intestinal valve, and intestinal villi are visible in the midgut. When fed with DHA-Selco^® enriched Artemia, H. guttulatus juveniles developed a severe condition of overinflation of the gas bladder. The continuous overinflation of the gas bladder forced air into the gut (48 h after the first meal), resulting in overinflation of both the gut and the gas bladder (72 h after the first meal), and death occurred within 120 h after the first meal. When fed natural copepods, H. guttulatus juveniles continued a normal feeding activity with no signs of intestinal disorders, and the gas bladder and intestine maintained their normal shape. This is the first study to positively associate gas bladder overinflation of juvenile seahorses with nutritionally unbalanced diets, and not to gas supersaturation alone. It is therefore necessary to develop more adequate feed and/or enrichment products to improve the survival of juvenile seahorses in captivity.     

Effect of parasitism on the pharmacokinetic disposition of ivermectin in lambs

The aim of this study was to investigate the effect of parasitism on plasma availability and pharmacokinetic behaviour of ivermectin (IVM) in lambs. Fourteen greyface Suffolk lambs (26.8 +/- 2.2 kg body weight) were selected for this study. Seven pairs of lambs were allocated into two groups in order to obtain an approximately even distribution. Group I (non-parasitized) was pre-treated by three repeated administrations of 5 mg/kg of fenbendazole (Panacur), in order to maintain a parasite-free condition. The lambs in group II (parasitized) did not receive any anthelmintic treatment and the natural infection was sustained by an oral inoculation of infective stages of nematode parasites. After the 85-day pre-treatment period both groups of animals were treated with IVM (200 microg/kg, Ivomec) by subcutaneous injection in the shoulder area. Both groups of animals were maintained under similar conditions of feeding and management. Blood samples were collected by jugular puncture at different times between 0.5 h and 25 days post-treatment. After plasma extraction and derivatization, samples were analysed by high-performance liquid chromatography with fluorescence detection. A computerized kinetic analysis was performed and data were compared using the unpaired Student's t-test. The parent molecule was detected in plasma between 30 min and either 12 (parasitized) or 20 (no parasitized) days post-IVM treatment. The area under the curve values of the parasitized group (75.2 +/- 15.5 ng x d/ml) were significantly lower that those observed in the parasite-free group (134.3 +/- 15.7 ng x d/ml). The mean residence time (MRT) of the parasitized group (2.93 +/- 0.16 days) was significantly lower than the MRT of healthy group (3.93 +/- 0.29 days). The results of this study have shown that a change in body condition followed by a parasitic infection is associated with significant changes in plasma disposition of IVM when it is administered subcutaneously to parasitized lambs. Therefore, variations in the condition induced by parasitism should be considered when these anthelmintics are used for treating parasitized animals.     

Preharvest aminoethoxyvinylglycine treatments reduce internal browning and prolong the shelf-life of early ripening pears

The effect of aminoethoxyvinylglycine (AVG) on internal browning (IB) and keeping quality of early maturing European pears cv ‘Camusina di Genova’ and ‘Camusina di Bonarcado’ was examined over 10 days of storage at 18 °C. AVG was applied at 125 or 250 mg/L 2 weeks before harvest. At harvest fruit treated with AVG was less ripe than control fruit, being significantly firmer and experiencing lower values of maturity stage (based on ground color), maturity index (calculated value) and IB, depending on the AVG dose and cultivar. During storage, there was no treatment-dependent difference in titratable acidity and total soluble solids of juice, while both treatments reduced ethylene and respiration rates, delayed the ripening process and lowered the incidence of IB and the loss of firmness, especially when applied at 250 mg/L. In addition, AVG treatment significantly reduced decay development in both cultivars, mainly when it was applied at 250 mg/L. This effect was related to the delay of ripen and to possible inhibition of ethylene production by the pathogens and/or infected tissues.     

Concordance of c‐kit Mutational Status in Matched Primary and Metastatic Cutaneous Canine Mast Cell Tumors at Baseline

Background

Mutation analysis of proto‐oncogene c‐kit (c‐kit) is advisable before starting treatment with tyrosine kinase inhibitors in dogs with mast cell tumor (MCT), including those with metastatic disease. Testing is usually performed on primary tumors, assuming that c‐kit mutation status does not change in metastasis.

Hypothesis/Objectives

To give an insight into the mutational processes and to make a recommendation on the use of c‐kit mutational analysis in the clinical setting.

Animals

Twenty‐one client‐owned dogs with metastatic MCT.

Methods

Dogs undergoing resection or biopsy for both primary and matched metastatic MCT were prospectively enrolled. Total RNA or DNA was extracted from primary MCT and corresponding metastases. Exons 8, 9, and 11 were amplified by PCR and sequenced. Genetic features between primary MCT and metastases were compared. Their correlation with clinicopathologic features was investigated.

Results

Concordance (mutated or wild‐type) of mutational status, evaluable in 21 primary and matched metastatic (20 nodal and 1 splenic) MCTs, was 100%. Three new c‐kit mutations were identified. No significant correlation was detected between c‐kit mutation and clinicopathologic features.

Conclusions and Clinical Importance

Proto‐oncogene c‐kit mutational status is conserved between any primary and its matched secondary tumor, suggesting that both can be used for c‐kit mutational testing. Targeted therapies might be also used to treat metastatic disease.     

Development of a web tool for action threshold evaluation in table grape pest management

Pest control is a major issue in agricultural management due to crop yield losses caused by pests. In this context, integrated pest management aims to suppress pest populations below an action threshold to minimize their impact. This paper presents the development of a web tool based on the Spanish regulations for the integrated pest management of table grapes; this provides decision support for evaluating when a particular pest action threshold has been crossed thus affecting table grape crops. The tool was built using a model-driven software development approach that enables software system generation from the problem’s knowledge model. The design of the knowledge bases which contain the system’s decision rules is also described. It is divided into knowledge bases that contain general knowledge related to the table grape crop as well as several specific knowledge bases (one per pest) containing the reasoning model that deduces the risk associated with a particular pest. The software has been designed by applying the model-driven development method thus making the system flexible, easy to evolve and adaptable whenever a new pest has to be incorporated into the software.     

Farm-SAFE: the process of developing a plot- and farm-scale model of arable,forestry, and silvoarable economics

Financial feasibility and financial return are two key issues that farmers and land owners consider when deciding between alternative land uses such as arable farming, forestry and agroforestry. Moreover regional variations in yields, prices and government grants mean that the relative revenue and cost of such systems can vary substantially within Europe. To aid our understanding of these variations, the European Commission sponsored a research project called “Silvoarable Agroforestry For Europe” (SAFE). This paper describes the process of developing a new economic model within that project. The initial stages included establishing criteria for the model with end-users and reviewing the literature and existing models. This indicated that the economic model needed to allow comparison of arable farming, forestry and agroforestry systems at a plot- and a farm-scale. The form of comparisons included net margins, net present values, infinite net present values, equivalent annual values, and labour requirements. It was decided that the model would operate in a spreadsheet format, and the effect of phased planting patterns would be included at a farm-scale. Following initial development, additional user feedback led to a final choice on a model name, a final method of collating input data, and the inclusion of field-based operations such as varying the cropped area, replacing dead trees, and pruning. In addition options in terms of improved graphical outputs and the ability to undertake sensitivity analysis were developed. Some of the key lessons learnt include the need to establish clear model criteria and the benefits of developing a working prototype at an early stage to gain user-feedback.     

Chemical and biochemical properties as potential indicators of disturbances

 The response of a series of soil microbial, chemical, and enzymatic chacacteristics to two different tillage systems (conventional and no-tillage) and two crop rotations (continuous corn and soybean–corn) was evaluated in a long-term field experiment in the Rolling Pampas Region, Marcos Juárez, Córdoba, Argentina. The parameters studied included: oxidizable, soluble and respiration C, total and hydrolyzable N, microbial activity, ammonifiers, nitrifiers, cellulolytic and total microflora, protease and urease activities. After 15 years, oxidizable C, total N and hydrolyzable N showed no differences regarding no-tillage systems. However, differences were found regarding control soil. While soluble C did not exhibit any significant differences, respiration C and microbial activity were indicators sensitive to different treatments. Enzymatic activities, protease in particular, did reflect changes due to management. Fluctuation in microbial population counts were more related to plant residues than to tillage systems. Received: 29 May 1999