Ph 70–23: A new acaricide and insecticide interfering with chitin deposition

PH 70–23 is a new benzoylphenylurea interfering with chitin deposition. In larvae of Spodoptera littoralis, incorporation of N-acetyl-glucosamine into chitin was equally inhibited by PH 70–23 and diflubenzuron, the first commercially available benzoylphenylurea. In contrast to diflubenzuron, which is active only against insects and eriophyid mites, PH 70–23 has the advantage of also being highly active on spider mites. The latter activity might be partly due to leaf penetration of PH 70–23. Laboratory experiments indicate PH 70–23 to have a better ovo-larvicidal activity than the commercial acaricides tested (cyhexatin, dicofol, fenbutatin oxide and tetradifon) against Tetranychus cinnabarinus, T. turkestani, T. urticae and Panonychus ulmi. A method in which eggs were deposited on residues of cyhexatin or fenbutatin oxide resulted in much lower activities than application of the spray liquid after egg deposition. Activities of PH 70–23, dicofol and tetradifon were hardly influenced by this difference in the test method. The direct contact activity of PH 70–23 on eggs of mites is influenced by the relative humidity and the age of the eggs. The total ovolarvicidal activity of PH 70–23 is only slightly positively influenced by the relative humidity, however. Ovicidal activity of PH 70–23 is also achieved by transovarial transmission. The compound does not influence the fertility of the mites. Comparison of a strain of T. urticae, resistant to dicofol, parathion and tetradifon, with a susceptible strain indicated absence of cross-resistance to PH 70–23. Compared to diflubenzuron, PH 70–23 shows an interesting shift in the spectrum of insecticidal activity.     

A Study of the Ability of a TK‐Negative and gI/gE‐Negative Pseudorabies Virus (PRV) Mutant Inoculated by Different Routes to Protect Pigs Against PRV Infection

The capacity of a TK‐negative (TK ^‐) and gI/gE‐negative (gI/gE ^‐) pseudorabies virus (PRV) mutant to protect pigs against Aujeszky's disease carried out by experimental infection with a virulent PRV strain, was tested. There were three groups, each of four susceptible pigs which were inoculated twice by two different schedules. Group 1 received the modified virus by the intradermal (first inoculation)‐intramuscular (second inoculation) routes; group 2 was treated by the intranasal (first inoculation)‐intramuscular (second inoculation) routes. The third group was left untreated as the control. All of the pigs were challenged intranasally with a virulent PRV strain and they were subsequently injected with dexamethasone. Two pigs in each group were necropsied on days 5 and 15 after dexamethasone inoculation. The challenge exposure resulted in mild clinical signs, increase in growth and a shorter period of virus shedding in vaccinated pigs, whereas the control group showed severe signs of Aujeszky's disease. No difference in the titre of the virulent virus which was excreted by pigs of all three groups, was observed and all animals seroconverted. Both the mutant strain and the wild‐type virus established a latent infection although only the latter was reactivated and shed. Slight lesions were observed in target tissues of the vaccinated animals and no significant differences were detected between the two inoculation schedules.     

Evaluation of effectiveness of Insegar (fenoxycarb 250 g/kg) WP against Phyllocnistis citrella Stainton (Lep., Gracillariidae) and its effect on Cales noacki How. (Hym., Aphelinidae)

Aiming to control the citrus leafminer Phyllocnistis citrella St. while at the same time protecting the biological equilibrium and mainly the beneficial insect Cales noacki, experiments have taken place in the regions of Argolis and Fthiotis, Greece in 1996 and 1997. Insegar (fenoxycarb) 2 5 WP was applied on young citrus trees. During 1996, the compound, applied every 10 days at a rate of 30 g/hI (with or without adjuvant), gave satisfactory protection from P. citrella without substantially harming C. noacki populations. No phytotoxicity symptoms were observed during the experiments.     

Initial solar irradiance determinations from nimbus 7 cavity radiometer measurements

Preliminary results from solar radiation measurements from the earth radiation budget experiment on the Nimbus 7 satellite yield a mean value of 1376.0 watts per square meter for the "solar constant" from 16 November 1978 to 15 May 1979. The observed variability (root-mean-square deviation) is +/- 0.73 watt per square meter (+/- 0.05 percent) for the period.     

MODELLING LEACHING OF INORGANIC Hg(II) IN A SCANDINAVIAN IRON-HUMUS PODZOL - VALIDATION AND LONG-TERM LEACHING UNDER VARIOUS DEPOSITION RATES

Increasing mercury contents are reported from freshwater systems and fish in northern Europe and North America. Mercury input from soils is a major source with the leaching being affected by increased atmospheric mercury deposition compared to pre-industrial times and by other environmental conditions such as acid rain. The results of a mathematical model-calculation of vertical inorganic Hg(II) leaching in a Scandinavian iron-humus podzol under different atmospheric input rates of mercury are presented. Leaching under background rain conditions was calculated to be considerably stronger than under acid rain conditions. Increasing fractions of deposited soluble or solute atmospheric mercury were leached from the O _f(h)-horizon with decreasing soil content of soluble mercury under acid rain conditions; this effect was less pronounced under background rain conditions. The steady state concentrations of soluble mercury of the upper soil horizons were calculated and compared with the actual concentrations of total (= soluble + insoluble mercury) and extractable (= estimate of soluble) mercury measured in these horizons. The results indicate that even if the deposition of airborne mercury to soil is strongly reduced, the total mercury content of the soil decreases only slowly. It may take decades or even centuries before a new steady state concentration of total mercury is established in the soil. The decrease of the mercury concentration in the O _f(h)-horizon is probably largely dependent on the turnover of organic matter, binding most of the deposited airborne mercury in an insoluble form. Hence, present day mercury leaching is likely to be dominated by mercury deposited during former times and temporarily retained in an insoluble form in the organic matter.     

Pharmacokinetics of carprofen and firocoxib for medication control in racing greyhounds

Animals used in sport should be treated as required to ensure animal welfare but any such use of medication should also be controlled to ensure integrity. Pharmacokinetic studies on groups of six greyhounds were performed to measure plasma and urine levels of carprofen and firocoxib to inform medication control advice. Using the standard methodology for medication control the Irrelevant Plasma Concentration was determined as 20 and 2 ng/mL for carprofen and firocoxib, respectively. The Irrelevant Urine Concentration was also determined as 0.3 and 2 ng/mL for carprofen and firocoxib, respectively. These Irrelevant Plasma and Urine Concentrations will allow laboratory Screening Limits, Detection Times and Withdrawal Time advice to be determined and publicised by regulators of greyhound racing. The Screening Limits will also inform Recommended Limits of Detection if meat-containing residues of these medications are fed to greyhounds.     

Successful sterlet, Acipenser ruthenus L., propagation with synthetic LH-RH hormone

Abstract. The synthetic LH-RH (luliberine) has proved to be successful in inducing the ovulation of sterlet, Acipenser ruthenus L. Three dosages of LH-RH 50, along with carp pituitary, and 100 and 300 μg/kg of body weight were administered, and 100 and 300 μg of LH-RH/kg body weight were found to be successful in ovulation. Spawners were kept at low temperature (9–12°C). Forty-two hours after treatment the eggs entered ovulation in the ovary and became suitable for stripping. The ripening ratio for spawners varied between 75 and 83%. The eggs that could be obtained by opening the abdominal wall were fertilized with milt diluted with pond water to avoid polyspermism. The fertility of the stripped eggs was 89–90%. Despite a reduced number of subjects (12 treated, 2 control females), as a result of the favourable fertilization percentage, approximately 55 000 fingerlings were reared in tanks to approximately 5–7cm in size.     

Cross-linking behavior and foaming properties of bovine α-lactalbumin after glycation with various saccharides

α-Lactalbumin was glycated via the Maillard reaction in the dry state using various mono- and oligosaccharides. The reaction resulted not only in coupling of the saccharides to α-lactalbumin but also in cross-linked proteins. The glycation rate and the extent of cross-link formation were highly dependent on the saccharide used. Glycation by arabinose and xylose led to a very fast protein cross-link formation, whereas glucose showed a relatively low protein cross-linking ability. The stability of foams, created using the various glycated protein samples, depended on the type of saccharide used, the extent of glycation, and possibly the amount of cross-linked protein. Compared to nonmodified α-lactalbumin, glycation with rhamnose and fucose improved foam stability, whereas application of glucose, galacturonic acid, and their oligosaccharides did not exert a clear effect. Mass spectrometric analysis revealed that dehydration of the Amadori products is an indicator of the formation of protein cross-links.