Regulation of lysine metabolism and endosperm protein synthesis by the opaque-5 and opaque-7 maize mutations

Two high lysine maize endosperm mutations, opaque-5 (o5) and opaque-7 (o7), were biochemically characterized for endosperm protein synthesis and lysine metabolism in immature seeds. Albumins, globulins, and glutelins, which have a high content of lysine, were shown to be increased in the mutants, whereas zeins, which contain trace concentrations of lysine, were reduced in relation to the wild-type lines B77xB79+ and B37+. These alterations in the storage protein fraction distribution possibly explain the increased concentration of lysine in the two mutants. Using two-dimensional polyacrylamide gel electrophoresis of proteins of mature grains, variable amounts of zein polypeptides were detected and considerable differences were noted between the four lines studied. The analysis of the enzymes involved in lysine metabolism indicated that both mutants have reduced lysine catabolism when compared to their respective wild types, thus allowing more lysine to be available for storage protein synthesis.     

Effects of processing steps on the phenolic content and antioxidant activity of beer

A new analytical method (liquid chromatography-antioxidant, LC-AOx) was used that is intended to separate beer polyphenols and to determine the potential antioxidant activity of these constituents after they were allowed to react online with a buffered solution of the radical cation 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS(?+)). Using the LC-AOx method, it was possible to demonstrate that the extent of the antioxidant activity was very much dependent on the phenolic compound considered. The method was also applied to the analysis of beer extracts and allowed the evaluation of their antioxidant activity at different steps of beer processing: brewing, boiling, and fermentation. This study showed that the total antioxidant activity remained unchanged throughout beer processing, as opposed to the polyphenolic content, which showed a 3-fold increase. Hopping and fermentation steps were the main causes of this increase. However, the increase measured after fermentation was attributed to a better extraction of polyphenols due to the presence of ethanol, rather than to a real increase in their content. Moreover, this method allowed the detection of three unknown antioxidant compounds, which accounted for 64 ± 4% of the total antioxidant activity of beer and were individually more efficient than caffeic acid and epicatechin.     

X-ray photoelectron spectroscopy for wheat powders: measurement of surface chemical composition

The functional properties of wheat powders depend largely on the surface characteristics of their particles. X-ray photoelectron spectroscopy (XPS) has been considered to investigate the surface composition of wheat powders. The objective of the present study is to evaluate the ability of XPS to discriminate wheat components and to calculate the surface composition of wheat powders. First, XPS surveys for the main wheat isolated components (starch, proteins, arabinoxylans, and lipids) were determined. XPS results demonstrate that it is able to distinguish wheat proteins, polysaccharides, and lipids, but it is not able to distinguish starch and arabinoxylan because of their similarity in chemical structure. The XPS analyses of simple reconstituted wheat flours based on two components (starch and protein) or three components (by adding arabinoxylan) demonstrated the ability of XPS to measure the surface composition of the wheat flours. The surface composition of native wheat flour demonstrated an overrepresentation of protein (54%) and lipids (44%) and an underrepresentation of starch (2%) compared to the bulk composition. Results are discussed with regard to difficulties in discriminating arabinoxylans and starch components.     

Isolation from ducks of a hypervirulent strain of duck plague virus and an avian type 6 paramyxovirus

This paper describes the isolation and identification of a duck plague virus (DP) and a paramyxovirus (PMV₆), from the livers and intestines collected in 4-month old mule ducks, under fattening, exhibiting 75% mortality and necrotic-haemorrhagic gross lesions. These viruses were isolated in specific pathogen free (SPF) muscovy duck eggs and SPF chicken eggs respectively. Then the DP virus was adapted to duck and chicken fibroblasts. The disease was reproduced in 2-week old SPF muscovy ducklings, intramuscularly inoculated with the previous organs, as well as in contact ducks. From them, only the DP virus was isolated again. Experimentally the intramuscular inoculation of the duck plague French vaccinal strain, 4 h post contact, did not prevent the disease and did not decrease its severity.

Regarding the DP virus, the typical signs and lesions observed in experimentally infected muscovy ducks as well as the presence of intranuclear inclusions of the epithelial cells of their oesophagus, intestines, bursa of Fabricus and liver on the one hand, and on the other hand, of the epithelial cells of the duck egg chorio-allantoïc membrane and fibroblasts inoculated with the samples first defined, allowed the characterization of the virus. Direct electron microscopy, as well as the results of seroneutralization tests with different specific avian Herpes virus antisera confirmed the DP virus identification. Moreover the DP isolate was not antigenically different from the serotype actually known.

The haemagglutinating virus (PMV₆) was characterized by direct electron microscopy as well as with 18 specific avian Myxovirus antisera; its identification was confirmed too by the specific seroconversion observed 4 weeks post-inoculation of this virus, in 11 weeks old SPF muscovy ducklings.

Finally an assay was carried out to appreciate the pathogenicity of theses viruses inoculated either separately or associated. It showed the high pathogenicity of the DP strain. The PMV₆ was apathogenic and no synergic effect with the DP virus was demonstrated. It appears to be the first isolation of PMV₆ in France, to our knowledge. The epidemiological circumstances related to theses isolations are discussed. The failure of the emergency vaccination in contact ducks, might be attributed to the high virulence of the DP strain.     

Geosmin Production by Cyanobacteria (Blue-green Algae) in Fish Ponds at Auburn, Alabama

Studies on production of geosmin, the compound responsible for earthy-muddy flavor in water and fish, were carried out at the Auburn University Fisheries Research Station. Water was collected from ponds during 44 cyanobacterial bloom periods from April to September. Geosmin ( trans -1, 10-dimethyl- trans -9-decalol) was detected at levels averaging 4.77 μg/L when Anabaena species with straight trichomes were predominant. Lower geosmin concentrations were associated with blooms of Anabaena species with coiled trichomes, Microcystis aeruginosa , and Aphanizomenon flos-aquae , and averaged 0.24, 0.12, and 0.07 μg/L, respectively. Study of four Anabaena blooms over a period of 4–8 weeks showed that changes in geosmin were correlated significantly with changes in trichome abundance. Geosmin disappeared from the water in seven days when Anabaena died. Comparison of geosmin concentrations in raw and filtered water showed that, on average, 90% of the geosmin could be associated with the particulate fraction. Dissolved geosmin concentrations ranged from 0.07–0.85 μg/L.     

Serum biochemical parameters and embryo production during superovulatory treatment in dairy cattle

The objective of this study was to determine the relationship between the number of transferable embryos (TE) and various blood chemistry parameters as a reflection of the metabolic state of cows after superovulatory treatment. Forty-nine Holstein cows were subjected to superovulatory treatment for commercial embryo production. At the time of embryo harvest, individual blood samples were taken from cows for biochemical analysis. All embryos including dead ones as well as non-fertilized oocytes were counted in uterine lavage. Feed samples collected daily for a period of two weeks before embryo harvest, were analyzed for mycotoxins: vomitoxin, zearalenone and T-2 toxin. On average, cows produced 9.45 ± 5.60 embryos and oocytes of which 5.27 ± 4.20 were TE, 0.37 ± 0.80 were dead embryos and 3.82 ± 3.78 were non-fertilized oocytes. Higher concentrations of Mg and K were associated with a higher production of TE (p = 0.005 and p = 0.043, respectively) and higher activity of creatinine kinase was associated with a lower production of TE (p = 0.011).     

Swine infection with Trichinella spiralis: Comparative analysis of the mucosal intestinal and systemic immune responses

The immune protective response developed by swine against Trichinella spiralis is not yet fully understood, particularly at the mucosal level. This study aimed to characterise intestinal immunity to T. spiralis by comparison with the systemic response in specifically pathogen-free pigs. For this purpose, the kinetics of cytokine and antibody production were assessed in the intestinal mucosa and serum of swine infected with T. spiralis for up to 60 days post-infection (dpi). An ex vivo model of jejunum mucosa culture was used to collect the supernatant as a source of antibodies (Abs). Mucosal antibodies were observed by Western blot from 15 dpi, while serum antibodies were expressed from 20 dpi. Both sources of antibodies initially recognized a 110 kDa protein, followed by the identification of 35, 43/46 and 55/59 kDa proteins. IgG1 and IgA antibodies were strongly expressed within the mucosa. The expression levels of Type 1 (IFN-gamma, IL-12), Type 2 (IL-4, IL-6), pro-inflammatory (TNF-alpha) and regulatory (IL-10, TGF-beta) cytokines were assessed by RT-PCR in the intestinal mucosa and spleen. Both IL-10 and IFN-gamma mRNA levels were increased in mucosa, whereas IL-6 and IL-12 mRNA were expressed in spleen. Taken together, these results demonstrated a mixed Type 1/Type 2 profile, the Type 2 profile being dominant in the mucosa.     

Determination of Venus Winds by Ground-Based Radio Tracking of the VEGA Balloons

A global array of 20 radio observatories was used to measure the three-dimensional position and velocity of the two meteorological balloons that were injected into the equatorial region of the Venus atmosphere near Venus midnight by the VEGA spacecraft on 11 and 15 June 1985. Initial analysis of only radial velocities indicates that each balloon was blown westward about 11,500 kilometers (8,000 kilometers on the night side) by zonal winds with a mean speed of about 70 meters per second. Excursions of the data from a model of constant zonal velocity were generally less than 3 meters per second; however, a much larger variation was evident near the end of the flight of the second balloon. Consistent systematic trends in the residuals for both balloons indicate the possibility of a solar-fixed atmospheric feature. Rapid variations in balloon velocity were often detected within a single transmission (330 seconds); however, they may represent not only atmospheric motions but also self-induced aerodynamic motions of the balloon.