Isostasy in australia and the evolution of the compensation mechanism   总被引：2，自引：0，他引：2  

McNutt MK  Parker RL 《Science (New York, N.Y.)》1978,199(4330):773-775

A linear transfer function analysis has been applied to gravity and topographic data from Australia to calculate the isostatic response function of Dorman and Lewis. The Australian response function is considerably different from that calculated for the United States. The differences can be explained on the basis of an apparent evolution of the isostatic compensation mechanism in which viscoelastic creep occurs in the lithosphere and relaxes the initial long-wavelength elastic stresses.  相似文献   

The role of technology in enhancing low resource agriculture in Africa     

Bruce J. Horwith  Phyllis N. Windle  Edward F. MacDonald  J. Kathy Parker  Allen M. Ruby  Chris Elfring 《Agriculture and Human Values》1989,6(3):68-84

Traditional forms of farming, herding, and fishing are remarkably adapted to African conditions but these traditional approaches are being overtaken by modern pressures, particularly population growth. According to a report published by the Office of Technology Assessment (OTA), a nonpartisan analytical support agency of the U. S. Congress, one promising way to help African farmers and herders would be for development assistance organizations to focus more attention on the various forms of low-resource agriculture that predominate in Africa. In keeping with OTA's mission and primary audience, “Enhancing Agriculture in Africa: A Role for U. S. Development Assistance” (1988) is a policy-oriented synthesis of available technical information. The report provides Congress with a range of options that, if pursued, could help Africans enhance agriculture, increase their food security, and improve their lives. This paper is drawn from the larger OTA report, and it focuses on the role technology might play in enhancing low-resource agriculture. Readers should see the full assessment (OTA, 1988) for more information on policy considerations; the specific technologies mentioned; or a complete list of advisory panel members, workshops and participants, and commissioned papers. OTA's report comes at a critical time: for a variety of reasons—ranging from changing values to increased budget constraints—U. S. foreign assistance policy is undergoing a fundamental reevaluation. This review of the potential of low-resource agriculture, and options the United States might pursue to enhance this approach, was intended to aid in this reevaluation.  相似文献   

The complete primary structure of protein kinase C--the major phorbol ester receptor   总被引：71，自引：0，他引：71  

P J Parker  L Coussens  N Totty  L Rhee  S Young  E Chen  S Stabel  M D Waterfield  A Ullrich 《Science (New York, N.Y.)》1986,233(4766):853-859

Protein kinase C, the major phorbol ester receptor, was purified from bovine brain and through the use of oligonucleotide probes based on partial amino acid sequence, complementary DNA clones were derived from bovine brain complementary DNA libraries. Thus, the complete amino acid sequence of bovine protein kinase C was determined, revealing a domain structure. At the amino terminal is a cysteine-rich domain with an internal duplication; a putative calcium-binding domain follows, and there is at the carboxyl terminal a domain that shows substantial homology, but not identity, to sequences of other protein kinase.  相似文献   

Stimulation of cells by antibody   总被引：4，自引：0，他引：4  

W T Shearer  G W Philpott  C W Parker 《Science (New York, N.Y.)》1973,182(119):1357-1359

Tumor cell lines exposed to immunoglobulins specific for cell surface antigens developed increased cellular incorporation of [(125)I]iododeoxyuridine and [(3)H]thymidine (up to 200-fold increases over cells treated with normal rabbit immunoglobulins). Antibody-stimulated cells multiplied more rapidly and lived longer than control cells in tissue culture. These observations were made both with cells substituted with 2,4,6-trinitrophenol and purified antibody against 2,4,6-trinitrophenol, and with several cell lines and their respective whole-cell antibodies. Antibodies that were stimulatory at low concentrations were cytotoxic at high concentrations. These observations may have significance in regard to enhancing effects of antibodies on tumor cell growth in vivo.  相似文献   

Morphine: radioimmunoassay   总被引：11，自引：0，他引：11  

S Spector  C W Parker 《Science (New York, N.Y.)》1970,168(937):1347-1348

The development of a radioimmunoassay for morphine is described.The hapten morphine is made antigenic by coupling it to a protein at the phenolic group of the molecule. Extremely low concentrations of morphine (0.5 nanogram) can be measured by this assay procedure.  相似文献   

SOME SUGGESTIONS FOR NATIONAL SERVICE ON THE PART OF ZOOLOGISTS AND ZOOLOGICAL LABORATORIES     

Conklin EG  Forbes SA  Kofoid CA  Lillie FR  Morgan TH  Parker GH  Reighard J  Smith HM 《Science (New York, N.Y.)》1917,45(1173):627-630

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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   

Electronic origin of the inhomogeneous pairing interaction in the high-Tc superconductor Bi2Sr2CaCu2O8+delta     

Pasupathy AN  Pushp A  Gomes KK  Parker CV  Wen J  Xu Z  Gu G  Ono S  Ando Y  Yazdani A 《Science (New York, N.Y.)》2008,320(5873):196-201

Identifying the mechanism of superconductivity in the high-temperature cuprate superconductors is one of the major outstanding problems in physics. We report local measurements of the onset of superconducting pairing in the high-transition temperature (Tc) superconductor Bi2Sr2CaCu2O8+delta using a lattice-tracking spectroscopy technique with a scanning tunneling microscope. We can determine the temperature dependence of the pairing energy gaps, the electronic excitations in the absence of pairing, and the effect of the local coupling of electrons to bosonic excitations. Our measurements reveal that the strength of pairing is determined by the unusual electronic excitations of the normal state, suggesting that strong electron-electron interactions rather than low-energy (<0.1 volts) electron-boson interactions are responsible for superconductivity in the cuprates.  相似文献   

THE AMERICAN MORPHOLOGICAL SOCIETY     

Parker GH 《Science (New York, N.Y.)》1898,7(163):194-203

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THE AMERICAN MORPHOLOGICAL SOCIETY     

Parker GH 《Science (New York, N.Y.)》1897,5(114):388-392

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