Incompatibility Between the Dimorphic Flowers of Collomia grandiflora, a Cleistogamous Species     

Lord EM  Eckard KJ 《Science (New York, N.Y.)》1984,223(4637):695-696

The cleistogamous species Collomia grandiflora produces dimorphic cross-incompatible flowers on a single plant. The open or chasmogamous flower has smaller, flask-shaped stigmatic papillae, larger pollen grains, longer styles, and faster pollen tube growth rates down the style than the closed or cleistogamous flower. In intermorph crosses, pollen tube growth rates are greatly decreased and fertilization does not occur.  相似文献   

Renewed Interest in Food Irradiation: FDA ponders approval as proponents push it as an alternative to pesticides     

Sun M 《Science (New York, N.Y.)》1984,223(4637):667-668

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The Fifth Generation: Taking Stock: The Japanese computer project is approaching its third birthday; meanwhile, the American programs are finally getting organized     

Waldrop MM 《Science (New York, N.Y.)》1984,226(4678):1061-1063

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Groundwater contamination     

Bredehoeft JD  Usselman TM 《Science (New York, N.Y.)》1984,224(4655):1292

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Newton: in the presence of the creator     

Mahoney MS 《Science (New York, N.Y.)》1984,226(4670):39-40

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Venus: detailed mapping of maxwell montes region     

Alexandrov YN  Crymov AA  Kotelnikov VA  Petrov GM  Rzhiga ON  Sidorenko AI  Sinilo VP  Zakharov AI  Akim EL  Basilevski AT  Kadnichanski SA  Tjuflin YS 《Science (New York, N.Y.)》1986,231(4743):1271-1273

From October 1983 to July 1984, the north hemisphere of Venus, from latitude 30 degrees to latitude 90 degrees , was mapped by means of the radar imagers and altimeters of the spacecraft Venera 15 and Venera 16. This report presents the results of the radar mapping of the Maxwell Montes region, one of the most interesting features of Venus' surface. A radar mosaic map and contour map have been compiled.  相似文献   

Research Coterie Meets At NAS to Assess Budget: NAS assembles 400 representatives academe, industry, and government to discuss priorities for science     

Crawford M 《Science (New York, N.Y.)》1986,231(4743):1239

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Regulatory Tangle Snarls Agricultural Research in the Biotechnology Arena: For scientists, the immediate future remains uncertain while debate rages on the safety of field testing altered organisms and on how much federal regulation is required     

Crawford M 《Science (New York, N.Y.)》1986,234(4774):275-277

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Influence of site and variety on starch,hemicellulose and cellulose composition of wheats and their digestibilities by adult cockerels     

Margaret Longstaff  J. M. McNab 《British poultry science》1986,27(3):435-449

1. It has been shown that both the variety of wheat and the environment under which growth took place influenced the quantities of starch and cell wall carbohydrate contents of wheat.

2. The different varieties of wheat investigated contained different proportions of water‐soluble to water‐insoluble hemicelluloses.

3. By comparison of the arabinose to xylose ratios it was concluded that water‐soluble and insoluble arabinoxylans of wheat were branched to the same degree.

4. Starch from six wheat varieties grown in the U.K. was very well digested by adult cockerels and true metabolisable energy values of the wheats were high.

5. Small amounts of cell wall carbohydrates were digested by adult cockerels.  相似文献   

Effects of evisceration and storage temperature on changes in meat quality of traditional farm‐fresh Turkeys     

T. C. Grey  G. C. Mead  Nerys M. Griffiths  J. M. Jones 《British poultry science》1986,27(3):463-470

1. Conditions affecting the keeping quality of traditional farm‐fresh turkeys were investigated.

2. Storage of uneviscerated Wrolstad turkeys at 4 °C for 10 days caused no statistically significant changes in meat flavour or texture.

3. During further storage at —2 °C, however, there was a slight but significant change in flavour, which became more marked with time in birds which had been eviscerated after the initial period at 4 °C.

4. Both eviscerated and uneviscerated birds became slightly tougher during storage.

5. Initial holding at 4 °C increased the numbers of psychrotrophic bacteria on the skin by about 10³ but subsequent changes at — 2 °C were slight for uneviscerated birds.

6. Eviscerated carcases had higher counts than uneviscerated birds after storage at — 2 °C and, although ‘off’ odours were not detected, spoilage appeared to be imminent at the end of the 20‐d period.  相似文献