Determination of the Genital Tubercle Migration Period in Morada Nova Sheep Foetuses by Ultrasonography

The aim of this study was to determine the period of genital tubercle (GT) migration using ultrasonography in Morada Nova sheep foetuses (n = 117) from natural mating (NM) and frozen embryo transfer (ET) to determine the window when foetal sexing can be determined. The examinations were performed using transrectal ultrasonography with a dual-frequency linear transducer (6.0 and 8.0 MHz) from day 30-54 of pregnancy at 48-h intervals. The period of GT migration of foetuses produced by NM varied from 36 to 46 days of pregnancy, resulting in an average of 39.5 +/- 2.9 days. For foetuses derived from ET, GT migration varied from 42 to 52 days of pregnancy with an average of 48.5 +/- 3.3 days, being possible the GT of foetuses from ET start to migrate 96 h later even if they are of the same gender. Migration of the GT occurred earlier (p < 0.05) in foetuses produced by NM and sexing accuracy for triplet pregnancies (77.8%) was significantly inferior (p < 0.05) to single (100%) and twin (92.9%) pregnancies for foetuses derived by NM. The results allow one to conclude that foetal sexing can be done from the 50th day onwards in foetuses produced by NM and from the 55th day onwards in foetuses derived from ET, and that multiple pregnancies compromise the sexing accuracy by ultrasonography.     

Preliminary pharmacokinetics of tramadol hydrochloride after administration via different routes in male and female B6 mice

Objective

1) To determine the pharmacokinetics of tramadol hydrochloride and its active metabolite, O-desmethyltramadol (M1), after administration through different routes in female and male C57Bl/6 mice; 2) to evaluate the stability of tramadol solutions; and 3) to identify a suitable dose regimen for prospective clinical analgesia in B6 mice.

Differenzierung der beiden Erscheinungsformen der Spitzendürre (Monilinia laxa) an Sauerkirschen ermöglicht eine Reduktion des Fungizideinsatzes zur Blüte

Since the early nineties control of twig blight on sour cherries in Rheinhessen/Germany caused by Monilinia laxa has become more and more difficult. Severe twig blight incidence even occured during cold and dry periods despite several hours of wetness are necessary for flower infecions by M. laxa conidia. Also repeated fungicide applications during bloom did not provide reliable control of twig blight. Field and laboratory studies have been carried out from 2002–2005 to find the reasons for control failures and the infection process under cold and dry conditions. On the basis of field observations frost damage of flowers and inoculum transport from untreated old cherry trees could be excluded. Monitoring studies revealed that only M. laxa caused twig blight and not M. fructicola as assumed before. The reason for the severe twig blight damage is the fact that M. laxa causes 2 different forms of twig blight. Besides the well known and often described twig blight after flower infection during rainy periods a second form of twig blight exists also caused by M. laxa but starting from “latent” infections inside the twig. These “latent” or “early” twig blight symptoms already occur at full bloom even during dry weather periods. Fungicide applications at the flowering stage do not control this form of twig blight because M. laxa is already present inside the twig. A diagnostic system is described allowing a clear differentiation of the two forms of twig blight what will lead to a reduced number of fungicide applications. Only the “true” flower infections can be controlled by fungicide treatments.     

Heterologous expression of the P450 sterol 14α-demethylase gene from Monilinia fructicola reduces sensitivity to some but not all DMI fungicides

The cytochrome P450 sterol 14α-demethylase gene (MfCYP51) from Monilinia fructicola (G. Wint.) Honey was cloned and sequenced. The gene was 1680 bp in length (including introns) and was predicted to have two introns of 54 and 57 bp. The nucleotide sequence was 82.1, 53.4, 47.1, 45.1, and 33.6% and the amino acid sequence was 89.7, 76.1, 76.1, 71.8, and 66.9% identical to the CYP51 genes from Botrytis cinerea, Tapesia yallundae, T. acuformis, Erysiphe graminis, and Uncinula necator, respectively. Expression of MfCYP51 in PDR5::TN5 deficient Saccharomyces cerevisiae resulted in reduced sensitivity of the yeast transformants to myclobutanil but not to propiconazole, fenbuconazole or tebuconazole. A wildtype population of 33 M. fructicola isolates was significantly less sensitive to myclobutanil than to propiconazole, fenbuconazole, and tebuconazole. The sensitivity of the isolates to myclobutanil and the three other DMI fungicides included in this study was correlated positively, suggesting a similar or identical mode of action. The low sensitivity in M. fructicola wildtype isolates to myclobutanil could result from a less effective binding potential of the fungicide to the 14α-demethylase.     

Production of carbon dioxide and nitrous oxide in alkaline saline soil of Texcoco at different water contents amended with urea: A laboratory study

Soil of the former lake Texcoco is alkaline saline with pH often >10 and electrolytic conductivity (EC) >70 dS m^?1 with rapidly changing water contents. Little is known how fertilizing this area with urea to vegetate the soil would affect emissions of carbon dioxide (CO₂) and dynamics of N. Texcoco soil with electrolytic conductivity (EC) 2.3 dS m^?1 and pH 8.5 (TEXCOCO A soil), EC 2.0 dS m^?1 and pH 9.0 (TEXCOCO B soil) and 200 dS m^?1 and pH 11.2 (TEXCOCO C soil) was amended with or without urea and incubated at 40% of water holding capacity (WHC), 60% WHC, 80% WHC and 100% WHC, while emissions of nitrous oxide (N₂O) and CO₂ and dynamics of ammonium (NH₄⁺), nitrite (NO₂^?) and nitrate (NO₃^?) were monitored for 7 days. An agricultural soil served as control (ACOLMAN soil). The emission of CO₂ increased in the urea amended soil 1.5 times compared to the unamended soil, it was inhibited in TEXCOCO C soil and was >1.2 larger in soil incubated at 40%, 60% and 80% WHC compared to soil incubated at 100% WHC. The emission of N₂O increased in soil added with urea compared to the unamended soil, was similar in TEXCOCO A and B soils, but was <0.2 mg N kg^?1 soil day^?1 in TEXCOCO C soil and generally larger in soil incubated at 60% and 80% WHC compared to soil incubated at 40% and 100% WHC. The water content of the soil had no significant effect on the mean concentration of NH₄⁺, but addition of urea increased it in all soils. The concentration of NO₂^? was not affected by the water content and the addition of urea except in TEXCOCO A soil where it increased to values ranging between 20 and 40 mg N kg^?1. The concentration of NO₃^? increased in the ACOLMAN, TEXCOCO A and TEXCOCO B soil amended with urea compared to the unamended soil, but not in the TEXCOCO C soil. It decreased with increased water content, but not in TEXCOCO C soil. It was found that the differences in soil characteristics, i.e. soil organic matter content, pH and EC between the soils had a profound effect on soil processes, but even small changes affected the dynamics of C and N in soil amended with urea.     

Compatibility of traditional and novel acaricides with bumblebees (Bombus terrestris): a first laboratory assessment of toxicity and sublethal effects

BACKGROUND: This project assessed the potential hazards of different classical and novel acaricides against an important non‐target and beneficial insect for the pollination of wild flowers and cultivated crops, the bumblebee Bombus terrestris (L). Twenty‐three acaricides used commercially in the control of phytophagous mites (Acari) were tested in greenhouses and/or the open field. Side effects included acute mortality and also sublethal effects on nest reproduction. The different compounds were administered in the laboratory via three different worst‐case field scenario routes of exposure: dermal contact and orally via the drinking of treated sugar water and via treated pollen. The compounds were tested at their respective maximum field recommended concentration (MFRC), and, when strong lethal effects were observed, a dose–response assay with a dilution series of the MFRC was undertaken to calculate LC₅₀ values. RESULTS: From the different acaricide classes, several chemistries caused high levels of acute toxicity in bumblebee workers, especially bifenthrin and abamectin which resulted in 100% mortality by contact. In addition, several acaricides tested were found to have a detrimental effect on drone production. For oral exposures via treated sugar water, the dose–response assay showed the LC₅₀ values for abamectin, bifenazate, bifenthrin and etoxazole to be 1/15 MFRC (1.17 mg AI L^?1), 1/10 MFRC (9.6 mg AI L^?1), 1/83 MFRC (0.36 mg AI L^?1) and 1/13 MFRC (4.4 mg AI L^?1) respectively, indicating that their use should be carefully evaluated. CONCLUSION: Overall, the results suggest that most of the acaricides tested are compatible with bumblebees, with the exceptions of abamectin, bifenazate, bifenthrin and etoxazole. However, the risks also depended on the type of treatment. As a result, the sugar water treatment seems to present the worst‐case situation of exposure, indicating that this approach is suitable for determining the hazards of pesticides against bumblebees. Finally, it is suggested that future tier testing under more field‐related conditions is required for a final decision of their risks. Copyright © 2010 Society of Chemical Industry     

Integral Management Zones: A novel strategy for marine bivalve production in the Gulf of California,Mexico

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