Erythropoiesis in the rat: differential rates of DNA synthesis and cell proliferation   总被引：2，自引：0，他引：2  

F C Monette  J LoBue  A S Gordon  P Alexander  P C Chan 《Science (New York, N.Y.)》1968,162(858):1132-1134

Direct in vivo estimates of DNA synthesis time in early and late erythroblasts were obtained by using the H(3)- and C(14)-thymidine double-la-beling technique. A double-emulsion autoradiographic procedure was used to resolve the two isotopes. Early erythroblasts were found to proliferate at a rate about five times that of late cells. This results primarily from a shorter mean DNA synthesis time in early cells (2.5 hours) than in late cells (6.5 hours).  相似文献   

The retina of the newborn human infant   总被引：2，自引：0，他引：2  

I Abramov  J Gordon  A Hendrickson  L Hainline  V Dobson  E LaBossiere 《Science (New York, N.Y.)》1982,217(4556):265-267

We have examined a pair of eyes from a normal, full-term infant who died at 8 days as a result of accidental injury. Eyes were obtained immediately after death, fixed, and sectioned for light microscopy. Results from both eyes were substantially the same. The macular region was still drastically immature at 1 week. Even though a foveal depression existed, all cell layers were still present across it. Furthermore, the inner nuclear layer was divided into two separate layers. The receptor layer was reduced to one or two cells thick; receptors had both inner and outer segments, but they were very short and stumpy. The region of immaturity covered about 5 degrees of the retina. These findings suggest that the central region of a human infant's retina is probably not fully functional at birth.  相似文献   

Integration and stable germ line transmission of genes injected into mouse pronuclei   总被引：27，自引：0，他引：27  

J W Gordon  F H Ruddle 《Science (New York, N.Y.)》1981,214(4526):1244-1246

Genetic material has been successfully transferred into the genomes of newborn mice by injection of that material into pronuclei of fertilized eggs. Initial results indicated two patterns of processing the injected DNA: one in which the material was not integrated into the host genome, and another in which the injected genes became associated with high molecular weight DNA. These patterns are maintained through further development to adulthood. The evidence presented indicates the covalent association of injected DNA with host sequences, and transmission of such linked sequences in a Mendelian distribution to two succeeding generations of progeny.  相似文献   

Nimbus-7 coastal zone color scanner: system description and initial imagery     

Hovis WA  Clark DK  Anderson F  Austin RW  Wilson WH  Baker ET  Ball D  Gordon HR  Mueller JL  El-Sayed SZ  Sturm B  Wrigley RC  Yentsch CS 《Science (New York, N.Y.)》1980,210(4465):60-63

The Coastal Zone Color Scanner (CZCS) on Nimbus-7, launched in October 1978, is the only sensor in orbit that is specifically designed to study living marine resources. The initial imagery confirms that CZCS data can be processed to a level that reveals subtle variations in the concentration of phytoplankton pigments. This development has potential applications for the study of large-scale patchiness in phytoplankton distributions, the evolution of spring blooms, water mass boundaries, and mesoscale circulation patterns.  相似文献   

Submarine thermal sprirngs on the galapagos rift   总被引：2，自引：0，他引：2  

Corliss JB  Dymond J  Gordon LI  Edmond JM  von Herzen RP  Ballard RD  Green K  Williams D  Bainbridge A  Crane K  van Andel TH 《Science (New York, N.Y.)》1979,203(4385):1073-1083

The submarine hydrothermal activity on and near the Galápagos Rift has been explored with the aid of the deep submersible Alvin. Analyses of water samples from hydrothermal vents reveal that hydrothermal activity provides significant or dominant sources and sinks for several components of seawater; studies of conductive and convective heat transfer suggest that two-thirds of the heat lost from new oceanic lithosphere at the Galápagos Rift in the first million years may be vented from thermal springs, predominantly along the axial ridge within the rift valley. The vent areas are populated by animal communities. They appear to utilize chemosynthesis by sulfur-oxidizing bacteria to derive their entire energy supply from reactions between the seawater and the rocks at high temperatures, rather than photosynthesis.  相似文献   

Infrared echoes near the supernova remnant Cassiopeia A     

Krause O  Rieke GH  Birkmann SM  Le Floc'h E  Gordon KD  Egami E  Bieging J  Hughes JP  Young ET  Hinz JL  Quanz SP  Hines DC 《Science (New York, N.Y.)》2005,308(5728):1604-1606

Two images of Cassiopeia A obtained at 24 micrometers with the Spitzer Space Telescope over a 1-year time interval show moving structures outside the shell of the supernova remnant to a distance of more than 20 arc minutes. Individual features exhibit apparent motions of 10 to 20 arc seconds per year, independently confirmed by near-infrared observations. The observed tangential velocities are at roughly the speed of light. It is likely that the moving structures are infrared echoes, in which interstellar dust is heated by the explosion and by flares from the compact object near the center of the remnant.  相似文献   

Chemistry of the Natural Atmosphere. Peter Warneck. Academic Press, San Diego, CA, 1988. xiv, 757 pp., illus. $85. International Geophysics Series, vol. 41     

Gordon GE 《Science (New York, N.Y.)》1988,242(4875):121-122

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Circulation and melting beneath the ross ice shelf     

Jacobs SS  Gordon AL  Ardai JL 《Science (New York, N.Y.)》1979,203(4379):439-443

Thermohaline observations in the water column beneath the Ross Ice Shelf and along its terminal face show significant vertical stratification, active horizontal circulation, and net melting at the ice shelf base. Heat is supplied by seawater that moves southward beneath the ice shelf from a central warm core and from a western region of high salinity. The near-freezing Ice Shelf Water produced flows northward into the Ross Sea.  相似文献   

Plasma testosterone levels in the male rhesus: influences of sexual and social stimuli   总被引：3，自引：0，他引：3  

R M Rose  T P Gordon  I S Bernstein 《Science (New York, N.Y.)》1972,178(61):643-645

Four adult male rhesus monkeys were provided access individually to a group of receptive females. Each male assumed dominance and engaged in frequent copulations. Plasma testosterone levels increased two- to threefold during this period. Next, each male was subjected to sudden and decisive defeat by a large all-male group, and plasma testosterone fell following this experience. Two males were later reintroduced to the females, and plasma testosterone rose rapidly to the previous elevated levels.  相似文献   

A single IGF1 allele is a major determinant of small size in dogs   总被引：3，自引：0，他引：3  

Sutter NB  Bustamante CD  Chase K  Gray MM  Zhao K  Zhu L  Padhukasahasram B  Karlins E  Davis S  Jones PG  Quignon P  Johnson GS  Parker HG  Fretwell N  Mosher DS  Lawler DF  Satyaraj E  Nordborg M  Lark KG  Wayne RK  Ostrander EA 《Science (New York, N.Y.)》2007,316(5821):112-115

The domestic dog exhibits greater diversity in body size than any other terrestrial vertebrate. We used a strategy that exploits the breed structure of dogs to investigate the genetic basis of size. First, through a genome-wide scan, we identified a major quantitative trait locus (QTL) on chromosome 15 influencing size variation within a single breed. Second, we examined genetic variation in the 15-megabase interval surrounding the QTL in small and giant breeds and found marked evidence for a selective sweep spanning a single gene (IGF1), encoding insulin-like growth factor 1. A single IGF1 single-nucleotide polymorphism haplotype is common to all small breeds and nearly absent from giant breeds, suggesting that the same causal sequence variant is a major contributor to body size in all small dogs.  相似文献