Repellent effectiveness of seven plant essential oils, sunflower oil and natural insecticides against horn flies on pastured dairy cows and heifers

Plant essential oils (basil, geranium, balsam fir, lavender, lemongrass, peppermint, pine and tea tree), mixed with either sunflower oil or ethyl alcohol, were applied at 5% concentrations to the sides of Holstein cattle. Pastured cattle treated with essential oils diluted in sunflower oil had less flies than the untreated control for a 24-h period. However, the essential oil treatments were not significantly different than the carrier oil alone. Barn-held heifers treated with essential oils and sunflower oil alone had significantly less flies than the untreated control for up to 8 h after treatment. Basil, geranium, lavender, lemongrass and peppermint repelled more flies than sunflower oil alone for a period ranging from 1.5 to 4 h after treatments applied to heifers. All essential oils repelled > 75% of the flies on the treated area for 6 and 8 h on pastured cows and indoor heifers, respectively. Geranium, lemongrass and peppermint stayed effective for a longer duration. Essential oils mixed with ethyl alcohol demonstrated less repellence than when mixed with the carrier oil. Safer's soap, natural pyrethrins without piperonyl butoxide and ethyl alcohol alone were not efficient at repelling flies. Essential oils could be formulated for use as fly repellents in livestock production.

First-trimester ultrasound diagnosis of skeletal dysplasia associated with increased nuchal translucency thickness

A series of five cases of skeletal dysplasia is reported in which the diagnosis was reached at the 11-14-week routine ultrasound examination in our referral center. All five cases had increased nuchal translucency thickness (NT) associated with bone abnormalities. We review the current literature on skeletal dysplasia in the first trimester of pregnancy associated with increased NT.

[Dating biometry with crown-rump length, precision of a routine practice]

OBJECTIVE

The goal of this study was to determine the accuracy of an everyday practice for assessing gestational age by ultrasound and redefine the correction of gestational age policy.

MATERIALS AND METHODS

This study used first trimester measurements taken during a three-year period. We considered all births from pregnancies that began by an in vitro fertilization procedure. We examined 143 consecutive files containing 257 measurements made by 72 different operators. We applied two reference curves to calculate the date the pregnancy began and the centiles of the prediction interval for +/- 7, +/- 5 and +/- 3 days.

RESULTS

The prediction intervals for +/-7, +/-5, +/-3 days excluded 2%, 6%, and 25% respectively of the embryos from one of the two reference curves. These intervals were 1%, 5% and 20%, were better for the other curve.

CONCLUSION

Correction of gestational age has to take into consideration variations in the embryo length. We correct the gestational age only if the difference with ultrasound assessment is more than one week.

Congenital erythropoietic porphyria (Günther's disease): two cases with very early prenatal manifestation and cystic hygroma

Congenital erythropoietic porphyria (CEP) or Günther's disease is the rarest form of the porphyrias. The disease is usually diagnosed at birth or during early infancy, but rarely in utero. We describe here the first two cases of very early prenatal expression of CEP with cystic hygroma diagnosed at 14 weeks in the first fetus and at 19 weeks in the second. Both fetuses presented with severe nonimmune hydrops fetalis as early as 19 and 22 weeks, associated with intrauterine growth retardation, hyperechogenic kidneys and bones. Amniotic fluid was dark brown and uro- and coproporphyrin I was dramatically increased. Molecular screening of the CEP gene detected heterozygous C73R mutation in both fetuses, the other parental mutation being as yet unknown.

Selecting passive and active materials for 1.3 composite power transducers

1.3 PZT-polymer composites were fabricated using the dice and fill method with various PZT types and volume fractions. These composites were evaluated for power underwater transducer applications with an air backed and no matching layer configuration. Electrical input and acoustical output powers were monitored as a function of the drive level. Total acoustic power densities of 30 W/cm2 were obtained with a P189/epoxy piezocomposite vibrating at 350 kHz with a low duty cycle (1-5%) and with a 90% efficiency. Power densities up to 20 W/cm2 were measured with a 50% duty cycle. Evolution and destruction of the transducers were monitored versus increasing averaged power. It was observed that better efficiencies were obtained with low volume fraction configurations allowing natural acoustic impedance matching to water. It was found that hard PZT type (Navy III) are optimal compositions even for piezocomposite transducers. It is shown that, unlike a common belief, the polymer mechanical losses are comparable to those of the active ceramic justifying that 1.3 piezocomposites are suited for low-cost power applications. In fact, the main limitation induced by the polymer phase is a strong thermal breakdown when the temperature of the transducer approaches the glass transition region of the polymer. Measurements of the polymer losses as a function of the temperature were obtained confirming this point and offering interesting new alternatives for future composite power transducers.

Dating biometry during the first trimester: accuracy of an every-day practice

OBJECTIVE

The goal of this study was to determine the accuracy of an every-day practice for assessing gestational age by ultrasound measurement of the greatest embryonic length (GEL).

DESIGN

This retrospective study used measurements taken during the first trimester.

SUBJECTS

We considered all births in this hospital between 1 January 1992 and 31 December 1994 from pregnancies that began by an in-vitro fertilization procedure (IVF). We examined 143 consecutive files, containing 257 measurements made by 72 different operators.

METHODS

The precision of seven embryo growth curves was compared. We calculated for each curve its ability to predict (95% prediction interval) the date the pregnancy began, using these dated pregnancies.

RESULT

For GEL measurements between 3 and 80 mm, which includes most of our population, Robinson and Wisser (2) were the most appropriate curves. The 95% prediction interval was 9.5 and 10.2 days respectively.

CONCLUSION

Dating pregnancies in every-day practice with GEL is nearly as accurate as prospective studies with only one or two scanners.

Predictive value of transvaginal uterine Doppler assessment in an in vitro fertilization program

This study evaluates the prognostic value of uterine Doppler performed on the day of embryo transfer in an in vitro fertilization program. Patients were divided into two groups according to the type of ovarian stimulation. The Doppler investigation was carried out using vaginal sonography. The pulsatility index was used to evaluate the uterine blood flow pattern. The hormonal profile (estradiol, luteinizing hormone (LH) and progesterone) was correlated to Doppler results and to the pregnancy rate. The comparison between patients treated with analogs and those who were not shows a significant difference in their hormonal profile. In the first group, we found a higher estradiol and progesterone serum concentration. The LH level and the pulsatility index were statistically lower. The endometrium was thicker in patients treated with gonadotropin releasing hormone agonists. In the group of patients treated with analogs, the statistical analysis showed no significant difference in the mean pulsatility index value in women who achieved a pregnancy and in those who failed. In the group of patients who received no agonists, only one variable was significantly different: the mean age was lower in women who became pregnant. We observed no ongoing pregnancy in women who had a pulsatility index value higher than two standard deviations (pulsatility index = 3.55). We therefore suggest the use of this value as a threshold. Thus, if a patient has a high uterine artery impedance, cryopreservation should be used and embryo transfer should be postponed to a subsequent cycle, or embryo transfer delayed for a few days using co-culture. This study clearly shows the impact of hormonal response on the Doppler value and on the pregnancy rate. However, the use of a threshold value for uterine artery pulsatility index might have a clinical impact in the future management of patients attending an in vitro fertilization program.

Measurement of limb circumferences with three-dimensional ultrasound for fetal weight estimation

A large number of formulae have been published for fetal weight estimation. This study examines the possibility of using three-dimensional ultrasound to measure the limb circumference. This technology provides us with the opportunity to visualize two simultaneous, orthogonal planes, allowing the exact determination of the transverse plane at the mid-point of the limb. A total of 157 patients were scanned in the week prior to delivery. The following variables were measured in 154 fetuses: biparietal diameter, head circumference, transverse abdominal diameter, abdominal circumference, femur length, thigh circumference and arm circumference. The whole population was split into three subgroups according to the abdominal circumference centile (< 10th centile, 10-90th centile, and > 90th centile), because this single variable has the strongest correlation with neonatal weight (R = 0.901). With forward stepwise multiple regression analysis, four models were elaborated, one for the whole population and one for each subgroup. The small-for-dates fetuses need a targeted formula including only two variables, thigh circumference and femur length. Our data suggest that the thigh circumference measurement improves the estimation for growth-retarded fetuses and that the arm circumference improves the weight prediction for the others. The measurement of the two variables, made possible with three-dimensional ultrasound, has improved our results in fetal weight estimation.