Organophosphate resistance in olive fruit fly, Bactrocera oleae, populations in Greece and Cyprus

The olive fruit fly Bactrocera oleae (Gmelin) (Diptera: Tephritidae) is the most important pest of olives in countries around the Mediterranean basin. Its control has been based mostly on bait sprays with organophosphate insecticides (usually dimethoate or fenthion) for about 40 years. In the present study, the resistance status of olive fruit fly populations to dimethoate was examined in Greece and Cyprus over 2 years. Thirty-one populations from various regions of Greece, nine from Cyprus and one laboratory susceptible strain, which served as a control, were assayed by topical application of dimethoate. Considerable variation in the resistance levels to dimethoate was recorded in the populations of B. oleae, with resistance ratios ranging from 6.3 to 64.4 (ED(50) values 12.5-128.7 ng dimethoate per insect). The highest resistance ratios were found in populations from Crete, and the lowest in those from Cyprus. This variation could be attributed to different selection pressures from insecticidal applications among populations from the various regions. Migration of resistant genotypes, either autonomous or via commerce, may also be involved.     

Characterizing NAD-dependent alcohol dehydrogenase enzymes of Methylobacterium extorquens and strawberry (Fragaria x ananassa cv. Elsanta)

The methylotroph Methylobacterium extorquens (strain with CABI registration number IMI 369321), which has been isolated from strawberry (Fragaria x ananassa cv. Elsanta) callus cultures, was grown on a mixture of methanol (0.25% v/v) and 1,2-propanediol (0.75% v/v). The microbial biotransformation of 1,2-propanediol to 2-hydroxypropanal (lactaldehyde) was studied. The bacterial alcohol dehydrogenase (ADH) enzymatic activities were assessed, and the optimum pH for ADH activity was found to be pH 6.0. Enzyme assays were carried out for both the bacterial and the strawberry extracts to define the best substrate specificity. For Methylobacterium extorquens, the best substrates were found to be methanol (Km = 0.78 mM) and 1,2-propanediol (Km = 15.84 mM), whereas for strawberries, 1-propanol (Km = 3.54 mM) and ethanol (Km = 6.66 mM) were the best substrates. A wide variety of metals as well as EDTA were shown to decrease the enzymatic activity. Furthermore, SDS-PAGE experiments showed molecular weights of 45.0 and 24.6 kDa for the alcohol dehydrogenases of Methylobacterium extorquens and Fragaria x ananassa, respectively.     

The effect of pre-anaesthetic fasting time and type of food on gastric content volume and acidity in dogs

Objective  To investigate the effect of pre-anaesthetic fasting time and variety of food on gastric content (GC) volume and pH in dogs.
Study design  Randomized, cross-over, prospective experimental study.
Animals  Fifteen mongrel dogs (nine females and six males 1–4 years old, weighing 10–24.5 kg).
Methods  Each dog received the same seven treatments in random order: dry food 3 hours before anaesthesia (BA) (treatment 3D), canned food (half daily rate) 3 hours BA (treatment 3C), 0% fat cow milk 3 hours BA (treatment 3M), dry food 10 hours BA (treatment 10D), canned food 10 hours BA (treatment 10C), low fat canned food 10 hours BA (treatment 10F) and low protein canned food 10 hours BA (treatment 10P). All animals were pre-medicated with propionyl promazine and anaesthesia was induced with thiopental sodium and maintained with halothane. GC was aspirated using an orogastric catheter and its volume and pH were measured.
Results  Treatment 10F had significantly lower GC pH than all the 3-hour treatments. Treatments 10D and 10P had significantly lower pH than treatments 3D and 3C. Treatment 3M had significantly lower pH than the other 3-hour treatments. Treatment 3D had significantly greater gastric volume than treatments 3M, 10C, 10F and 10P.
Conclusions and clinical relevance  Canned food at half the daily rate administered 3 hours before anaesthesia did not increase significantly the GC volume compared to the other types of food used. The GC pH was also high. This type of food fed 3 hours before induction of anaesthesia may be of benefit in reduction of the incidence of gastro-oesophageal reflux during anaesthesia in dogs.     

Concentrations and Availability Indicators of Soil Heavy Metals; the Case of Children’s Playgrounds in the City of Athens (Greece)

This study reports on the concentrations, distribution, and availability of heavy metals in the children’s playground soils of Athens. Playgrounds were chosen because they are open city areas; they show relatively even spatial distribution within the district of Athens and are used by a great number of young children and their escorts on a regular basis. Samples were collected from 70 playground surface soils, representing more than 70% of the city’s playgrounds. Cu, Zn, Pb, Cr, Ni, Co, Mn, and Fe were extracted by aqua regia and by diethylene triamine pentaacetic acid (DTPA) to estimate total and available metal forms, respectively. Their mean total concentrations were 43, 174, 110, 80, 82, 22, 312, and 17?×?10³?mg kg^?1, respectively. The DTPA-extracted fraction showed much lower values, with means of 2.5, 7.8, 5.8, 1.5, 1.3, 0.4, 8.4, and 2.0 mg kg^?1 respectively, which, however, should be carefully monitored since they relate directly to the bioavailable fraction of heavy metals. Though mean values of metal concentrations are not particularly high, the calculated enrichment factors indicate site-specific cases of high enrichment with heavy metals. Considering that the bioavailable fraction of a metal is possibly a more appropriate indicator for the recent soil pollution history, availability ratios were calculated and their distribution was visualized over the entire city profile using the appropriate GIS software. It was shown that recent metal pollution events appear to have affected mostly playground sites in the southern and eastern part of the municipality.     

High incidence of seed transmission of Papaya ringspot virus and Watermelon mosaic virus, two viruses newly identified in Robinia pseudoacacia

Black locust (Robinia pseudoacacia L.) is an ornamental legume tree susceptible to several viruses. Virus diseases of black locust often go unrecognized making infected trees a prime inoculum source, not only for legumes, but also other plant species. In this communication we report, for the first time, two viruses, Papaya ringspot virus and Watermelon mosaic virus, associated with disease in black locust. Isolates of both viruses were partially characterized and seed transmission was examined. The high percentage of seed transmission suggests that this may be an important avenue for virus dissemination.     

Blood gas and acid-base status during tiletamine/zolazepam anaesthesia in dogs

OBJECTIVE: To evaluate the effect of the tiletamine/zolazepam (TZ) combination (Zoletil 100; Virbac, Carros, France) with and without atropine on blood gas values and acid-base status in dogs. STUDY DESIGN: Randomized cross-over experimental study. ANIMALS: Six healthy adult cross-bred dogs, weighing 11.0-18.5 kg. MATERIALS AND METHODS: Each dog received four different drug treatments at intervals of at least 15 days: (i) 5 mg kg(-1) intravenous (IV) TZ (TZ.IV); (ii) 10 mg kg(-1) intramuscular (IM) TZ (TZ.IM); (iii) atropine, 20 microg kg(-1) IV, followed 5 minutes later by 5 mg kg(-1) TZ IV (A.TZ.IV); and (IV) atropine (same dose) given 5 minutes before 10 mg kg(-1) TZ IM (A.TZ.IM). Arterial blood samples were collected from each dog before drug administration (baseline) at induction of anaesthesia (time 0) and 2, 5, 10 and 30 minutes thereafter. RESULTS: Transient hypoxaemia and respiratory acidosis were observed just after induction. PaO(2) and SaO(2) dropped, while H(+) concentration and PaCO(2) rose significantly above baseline values. In groups TZ.IV and A.TZ.IV, PaO(2) values as low as 6.0-6.4 kPa (45-48 mm Hg) were recorded. However, there was no significant difference in blood gas variables among the groups encountered during the evaluation period. The overall change in [HCO(3) (-)] and base excess (BE) was not significant among groups. Atropine did not affect the above variables. CONCLUSIONS AND CLINICAL RELEVANCE: Tiletamine/zolazepam injection may induce transient hypoxaemia and respiratory acidosis, but acid-base status changes are clinically unimportant. Particularly, close observation of dogs is recommended during the first 5-10 minutes after induction with TZ, especially in animals with cardiopulmonary disease. TZ should perhaps not be used in animals intolerant of tachycardia.     

Reduction of Pb,Zn and Cd Availability from Tailings and Contaminated Soils by the Application of Lignite Fly Ash

The effectiveness of lignite fly ash for stabilization of Pb,Zn and Cd in tailings and contaminated soils was examined. Flyash was mixed with the contaminated soil or oxidic tailingssamples at various doses and pot experiments were performed.The effectiveness of stabilization was mainly evaluated by thestandard US EPA TCLP toxicity test. The 5-stage sequentialextraction procedure was also applied to determine the form ofcontaminants in the fly ash amended soil or tailings samples.Complementary EDTA extraction tests were also carried out. Thefly ash treatment resulted in the reduction of TCLP solubilityof Pb, Zn and Cd to below the respective regulatory limits at5 and 10% w/w fly ash addition rates in tailings and soil,respectively. Speciation of lead, in the treated soil andtailings samples indicated that there was a significanttransition of the heavy metals form from the exchangeable andcarbonate fractions to reducible and residual, suggesting thatthe potential mechanisms of heavy metals retention are, apartfrom increase of pH, sorption on the oxides and hydroxidessurfaces and binding with the hydrated fly ash compounds.     

Towards sweet cherry (<Emphasis Type="Italic">Prunus avium</Emphasis> L.) breeding: phenotyping evaluation of newly developed hybrids

An increasing demand for cherry production (Prunus avium L.) in Greece led to the development of new high quality sweet cherry cultivars. Self-incompatibility in cherry is one of the most challenging issues for the species’ cultivation and top breeding priority. Τhe present study focuses on the development of new hybrids with improved traits such as productivity, fruit size, organoleptic characteristics and self-compatibility. For this purpose, thirty different cultivars were crossed and produced hybrids that were evaluated according to 34 morpho-physiological characteristics. The results were analyzed using the XLSTAT (version 2014.1) software and a dendrogram was constructed using the agglomerative hierarchical clustering method. Optimal hybrid clustering was achieved when characteristics of great economic importance such as fruit shape and size, growth habit and days to blooming were included in the analysis. Based on the results, new sweet cherry hybrids with the special character of self-compatibility were developed. Our findings provide crucial new information for sweet cherry future breeding programs and cultivation.