Chick embryo development can be irreversibly altered by early exposure to weak extremely-low-frequency magnetic fields

Several reports have shown that weak, extremely-low-frequency (ELF), pulsed magnetic fields (PMFs) can adversely affect the early embryonic development of the chick. In this study, freshly fertilized chicken eggs were exposed during the first 48 h of postlaying incubation to PMFs with 100 Hz repetition rate, 1.0 μT peak-to-peak amplitude, and 500 μs pulse duration. Two different pulse waveforms were used, having rise and fall times of 85 μs (PMF-A) or 2.1 μs (PMF-B). It has been reported that, with 2 day exposure, these fields significantly increase the proportion of developmental abnormalities. In the present study, following exposure, the eggs were allowed to incubate for an additional 9 days in the absence of the PMFs. The embryos were taken out of the eggs and studied blind. Each of the two PMF-exposed groups showed an excess in the percentage of developmental anomalies compared with the respective sham-exposed samples. This excess of anomalies was not significant for the PMF-A-treated embryos (P = 0.173), whereas it was significant for the PMF-B-exposed group (P = 0.007), which showed a particularly high rate of early embryonic death. These results reveal that PMFs can induce irreversible developmental alterations and confirm that the pulse waveform can be a determinant factor in the embryonic response to ELF magnetic fields. The data also validate previous work based on the study of PMFs' effects at day 2 of embryonic development under field exposure. © 1994 Wiley-Liss, Inc.     

Acanthodactyles of Tunisia: VIII--The southern acanthodactyles from south of Chott el Djerid

Applied to 135 Acanthodactylus, from eight clusters of collecting sites, a multidimensional analysis of 11 characters, mainly of colouring and scale patterns, providing 35 mathematical variables, reveals a hight intrapopulational variability. Samples dwelling on reg nebkhas and sandy knolls in the river beds are Acanthodactylus inornatus. Some specimens, in the sample from barkhanes and sand dunes areas, are morphologically close to A. longipes.     

shape In vitro effects of diacetoxyscirpenol (DAS) on human and rat granulo-monocytic progenitors

Diacetoxyscirpenol (DAS) is a trichothecene mycotoxin produced by various species of fungi. Trichothecenes are known as major contaminants of cereals and cereal-containing foods. DAS has been detected in agricultural products worldwide and persists in products after processing. In human as well as in animals, DAS consumption has been shown to induce haematological disorders (neutropenia, aplastic anemia). Granulo-monocytic progenitors (CFU-GM) from human umbilical cord blood and rat bone marrow have been cultured in the presence of DAS (from 10^-8 M to 5 × 10^-10 M) for 14 days. Study of concentration and effect relationships have shown a sharp effect of DAS on rat CFU-GM between 10^-7 M and 10^-8 M, while human CFU-GM are able to grow in the presence of 10^-8 M of the toxin. IC₅₀ values on day 14 are respectively, 7.6 × 10^-9 M for human CFU-GM and 6.2 × 10^-9 M for rat CFU-GM. This revised version was published online in June 2006 with corrections to the Cover Date.     

On-line evaluation of fermentation broth colour

Summary A novel method for evaluating pigment production during fermentation ofMonascus ruber has been developed and consists of reflectance measurement with a 10° observer under an artificial illuminant. A spectrophotometer was adapted to measure pigmentation during culture in a bioreactor. The lightness parameter L was the most useful information delivered by this sensor. An absorbency over 30 units at 480nm on batch cultures was estimated on-line without dilution. member of the GR Automatique - SARTA - CNRS