Parasitoids as selective agents in the symbiosis between lycaenid butterfly larvae and ants     

Pierce NE  Mead PS 《Science (New York, N.Y.)》1981,211(4487):1185-1187

The larvae of Glaucopsyche lygdamus (Lepidoptera: Lycaenidae) secrete substances that attract ants. In two field sites in Colorado, tending ants protect caterpillars of G. lygdamus from attack by braconid and tachinid parasitoids. This protection may have been an important feature in the evolution of the association between lycaenid larvae and ants.  相似文献   

Accelerated healing of incisional wounds in rats induced by transforming growth factor-beta   总被引：62，自引：0，他引：62  

T A Mustoe  G F Pierce  A Thomason  P Gramates  M B Sporn  T F Deuel 《Science (New York, N.Y.)》1987,237(4820):1333-1336

The role of polypeptide growth factors in the processes of inflammation and repair was investigated by analyzing the influence of transforming growth factor-beta (TGF-beta), applied directly to linear incisions made through rat dorsal skin. A dose-dependent, direct stimulatory effect of a single application of TGF-beta on the breaking strength of healing incisional wounds was demonstrated. An increase in maximum wound strength of 220 percent of control was observed at 5 days; the healing rate was accelerated by approximately 3 days for at least 14 days after production of the wound and application of TGF-beta. These increases in wound strength were accompanied by an increased influx of mononuclear cells and fibroblasts and by marked increases in collagen deposition at the site of application of TGF-beta. TGF-beta is thus a potent pharmacologic agent that can accelerate wound healing in rats.  相似文献   

A unified description of linear and nonlinear polarization in organic polymethine dyes     

Marder SR  Gorman CB  Meyers F  Perry JW  Bourhill G  Brédas JL  Pierce BM 《Science (New York, N.Y.)》1994,265(5172):632-635

An internal or external electric field F can drive the chemical structure, bond order alternation, and electronic structure of linear polymethine dyes from a neutral, bond-alternated, polyene-like structure, through a cyanine-like structure, and ultimately to a zwitterionic (charge-separated) bond-alternated structure. As the structure evolves under the influence of F, the linear polarizability alpha, the first hyperpolarizability beta, and the second hyperpolarizability gamma are seen to be derivatives, with respect to F, of their next lower order polarization (for alpha) or polarizability (for beta and gamma). These derivative relations provide a unified picture of the dependence of the polarizability and hyperpolarizabilities on the structure in linear polymethine dyes. In addition, they allow for predictions of structure-property relations of higher order hyperpolarizabilities.  相似文献   

Artificial placenta: two days of total extrauterine support of the isolated premature lamb fetus     

W M Zapol  T Kolobow  G G Pierce JEVUREK  R L Bowman 《Science (New York, N.Y.)》1969,166(905):617-618

A premature lamb fetus was totally sustained by extracorporeal perfusion with the use of a silicone-membrane blood oxygenator and parenteral nutritional support. The fetus remained in a metabolically stable state lasting several days.  相似文献   

PEAR BLIGHT IN CALIFORNIA     

Pierce NB 《Science (New York, N.Y.)》1902,16(396):193-194

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The chemical genomic portrait of yeast: uncovering a phenotype for all genes     

Hillenmeyer ME  Fung E  Wildenhain J  Pierce SE  Hoon S  Lee W  Proctor M  St Onge RP  Tyers M  Koller D  Altman RB  Davis RW  Nislow C  Giaever G 《Science (New York, N.Y.)》2008,320(5874):362-365

Genetics aims to understand the relation between genotype and phenotype. However, because complete deletion of most yeast genes ( approximately 80%) has no obvious phenotypic consequence in rich medium, it is difficult to study their functions. To uncover phenotypes for this nonessential fraction of the genome, we performed 1144 chemical genomic assays on the yeast whole-genome heterozygous and homozygous deletion collections and quantified the growth fitness of each deletion strain in the presence of chemical or environmental stress conditions. We found that 97% of gene deletions exhibited a measurable growth phenotype, suggesting that nearly all genes are essential for optimal growth in at least one condition.  相似文献   

THE LIFE AND SERVICES OF PROFESSOR JOHN TROWBRIDGE     

Lyman T  Richards TW  Pierce GW 《Science (New York, N.Y.)》1923,57(1483):631-632

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Ecology. Metalife!     

Dobson A 《Science (New York, N.Y.)》2003,301(5639):1488-1490

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Risks from low doses of radiation     

Pierce DA  Preston DL 《Science (New York, N.Y.)》1996,272(5262):632a-633b

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Man's Role in Space     

Pierce JR 《Science (New York, N.Y.)》1987,236(4806):1161

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