The ploidy levels of the twenty-two yam (Dioscorea cayenensis-D. rotundata complex) cultivars within germplasm Cameroon Guinea yam were determined by flow cytometry. Three different ploidy levels (4x,6x, 8x) were detected within the samples analysed. Fifteen cultivars were tetraploids, five were hexaploids, and two were octoploids. The cultivar group EKOTO showed a high level of ploidy variation with tetraploid, hexaploid and octoploid cultivars. The hexaploid nature of cultivars Dobnawo and Bilougnou supported the hypothesis that they are hybrids between cultivars of the EKOTO group and either the KPE or BAKOKAE groups.

Total amount of the water vapour in the atmosphere is defined as a column of precipitable water in g/square cm. Precipitable water represents a certain water layer that we often indicate as an optical depth of water vapour. To express the optical depth of water vapour various empirical relations were used. A comparison of the obtained results shows that the corresponding values very often differ by 10%. Assuming that the optical path at the upper boundary of the atmosphere equals zero, then we can express the corrected optical depth of the water vapour at the arbitrary level by the given relation

10 páginas, 6 figuras y 1 tabla estadística | Isozyme variability was assessed among the principal species of the cereal cyst nematode complex to complete and enhance the information provided by classical nematode systematics, in order to clarify inter- and intraspecific relationships within this complex. Twenty populations of cereal cyst nematodes (Heterodera avenae, H. filipjevi, H. latipons and H. mani) were compared by means of five different isoenzymatic systems (esterase, malate dehydrogenase, phosphoglucoisomerase, phosphoglucomutase and superoxide dismutase) using isoelectrofocusing (IEF) on the electrophoretic separation. The results are in agreement with previous morphological and biochemical characterizations, which established genetic diversity between the Gotland strain and H. avenae and identified the Gotland strain with H. filipjevi. Populations from Israel, all included in the H. avenae group, exhibited well-defined intraspecific dissimilarity. The highest degree of polymorphism was found in the H. avenae group for all five enzymatic systems studied. The H. mani population was also included in the H. avenae group by these isozyme analyses. Malate dehydrogenase, phosphoglucoisomerase and phosphoglucomutase isozymes, fractionated for the first time by IEF in the cereal cyst nematode complex, displayed a higher level of polymorphism than using conventional electrophoresis. Isoelectric focusing has proved to be a useful tool for detecting genetic diversity within and among species of the cereal cyst nematode complex and for taxonomic purposes. | CICYT AGF98-1057-CO4 | Peer reviewed

The tetanus immunisation results obtained in the two sexes, were compared in animal models. Complete immunisation series of weaned, adult and aged guinea-pigs were performed with aluminium phosphate adsorbed purified tetanus toxoid as well as with typhoid-tetanus vaccine (TY-TE) containing lipopolysaccharide. The results were in accordance with our previous observations in humans. Tetanus immunisation series on guinea pigs it can be concluded that TAT may be influenced by the effects of sex chromosomes as well as of sexual hormones.

Clenbuterol is a beta2 agonist/antagonist bronchodilator marketed as Ventipulmin and is the only member of this group of drugs approved by the US Food and Drug Administration (FDA) for use in horses. Clenbuterol is a class 3 drug in the Association of Racing Commissioners International (ARCI) classification system; therefore, its identification in postrace samples may lead to sanctions. Recently, the sensitivity of postrace testing for clenbuterol has been substantially increased. The objective of this study was to determine the 'detection times' for clenbuterol after administration of an oral clinical dose (0.8 g/kg, b.i.d.) of Ventipulmin syrup. Five horses received oral clenbuterol (0.8 g/kg, b.i.d.) for 10 days, and urine concentrations of clenbuterol were determined by an enhanced enzyme-linked immunoabsorbent assay (ELISA) test and gas chromatography/mass spectrometric (GC/MS) analysis by two different methods for 30 days after administration. Twenty-four hours after the last administration, urine concentrations of apparent clenbuterol, as measured by ELISA, averaged about 500 ng/mL, dropping to about 1 ng/mL by day 5 posttreatment. However, there was a later transient increase in the mean concentrations of apparent clenbuterol in urine, peaking at 7 ng/mL on day 10 postadministration. The urine samples were also analysed using mass spectral quantification of both the trimethylsilyl (TMS) and methane boronic acid (MBA) derivatives of clenbuterol. Analysis using the TMS method showed that, at 24 h after the last administration, the mean concentration of recovered clenbuterol was about 22 ng/mL. Thereafter, clenbuterol concentrations fell below the limit of detection of the TMS-method by day 5 after administration but became transiently detectable again at day 10, with a mean concentration of about 1 ng/mL. Derivatization with MBA offers significant advantages over TMS for the mass spectral detection of clenbuterol, primarily because MBA derivatization yields a high molecular weight base peak of 243 m/z, which is ideal for quantitative purposes. Therefore, mass spectral analyses of selected urine samples, including the transient peak on day 10, were repeated using MBA derivatization, and comparable results were obtained. The results show that clenbuterol was undetectable in horse urine by day 5 after administration. However, an unexpected secondary peak of clenbuterol was observed at day 10 after administration that averaged approximately 1 ng/mL. Because of this secondary peak, the detection time for clenbuterol (0.8 g/kg, b.i.d. x 10 days) is at least 11 days if the threshold for detection is set at 1 ng/mL.

Over 30 years ago, Clostridium perfringens was reported as a contaminant of the processing plant and processed carcasses of broiler chickens. Poultry processing procedures and methods for detecting C. perfringens have changed since that time. Therefore, a study was conducted to determine the incidence and numbers of C. perfringens in the water of the scald tank, the water of the chill tank, and the rinse water of the processed carcasses from modern broiler chicken processing plants. In trial 1, collected samples were inoculated into iron milk medium (IMM) and incubated at 46 degrees C for 18 h (the traditional method) or at 37 degrees C for 3 h followed by incubation at 46 degrees C for 15 h (an injury recovery method). Each of three preselected broiler chicken flocks from two integrators were the first processed for that processing shift. The overall incidence of confirmed C. perfringens in samples associated with the three flocks was 40% of postprocessing scald water samples, 13% of preprocessing chill water samples, 13% of postprocessing chill water samples, and 19% of carcass rinses. The incidence of C. perfringens in samples incubated in IMM using the injury recovery procedure was significantly higher than in samples incubated in IMM by the traditional method, but only when all samples associated with the three flocks were pooled. In trial 2, water samples from each tank of a three-tank counterflow scalder, water samples from the prechill and chill tank, and samples of carcass rinses were collected in the middle of a processing shift during multiple visits to a processing plant. Samples were inoculated into IMM with neomycin and polymyxin B sulfate (IMMA) and incubated using the traditional and injury recovery procedures. The incidence of C. perfringens in water samples was 100% from scald tank 1, 100% from scald tank 2, 100% from scald tank 3, 88% from the prechill tank, and 63% from the chill tank. The incidence in carcass rinse samples was 67%. The mean most probably number (MPN) of C. perfringens for contaminated samples decreased from log10 5.07/100 ml of water in scald tank 1 to log10 1.26/100 ml of water in the chill tank. The mean MPN in carcass rinse samples was log10 1.20 C. perfringens per 100 ml. The incidence and mean MPN of C. perfringens in these samples after heat shock at 75 degrees C for 20 min was somewhat less, but high enough to indicate that much of the contamination arises from heat-resistant spores of this organism. In trial 2, there were no differences in incidence and MPN of C. perfringens in samples incubated in IMMA with the traditional method or the injury recovery method.

To investigate the genetic structure of the firefly population, known as Luciola lateralis, in Korea. We determined on a portion of mitochondrial Cytochrome Oxidase Subunit I (COI) gene sequences (403 bp) for phylogenetic comparison. Sequence analysis of 80 individuals collected from 12 localities revealed 24 haplotypes, ranging in sequence divergence from 0.2% to 4.0%. Phylogenetic analyses using PAUP, PHYLIP, and networks subdivided L. lateralis into two clades (termed clade A and B) and the nucleotide divergence between them was 2.2%.

A. Dansi, H. Mignouna, M. Pillay, S. Zok, 'Ploidy variation in the cultivated yams (Dioscorea cayenensis-Dioscorea rotundata complex) from Cameroon as determined by flow cytometry', Euphytica, vol. 119, pp.301-307, 2001