Biological phosphonates: determination by phosphorus-31 nuclear magnetic resonance   总被引：2，自引：0，他引：2  

T Glonek  T O Henderson  R L Hilderbrand  T C Myers 《Science (New York, N.Y.)》1970,169(941):192-194

Advanced methods of phosphorus-31 nuclear magnetic resonance spectroscopy provided a method whereby biological phosphonates and phosphates can be determined on simple lipid fractions of biological origin. The spectra consist of two easily distinguished resonance bands; one corresponds to families of phosphonates, and the other corresponds to families of orthophosphates.  相似文献   

Alcohol drinking: abnormal intake caused by tetrahydropapaveroline in brain   总被引：5，自引：0，他引：5  

R D Myers  C L Melchior 《Science (New York, N.Y.)》1977,196(4289):554-556

Tetrahydropapaveroline (THP), a dopamine-dopaldehyde condensation product, was delivered directly into the cerebral ventricle of rats automatically every 15 minutes for 12 days. The animals were given access to both water and ethylalcohol, the latter being presented in 12 concentrations from 3 to 30 percent. Within 3 to 6 days of the start of the infusion of THP, the rats, which normally rejected alcohol, drank alcohol solutions in increasingly excessive amounts; this was accompanied by symptoms that were similar to those of withdrawal and intoxication. These results provide evidence that an abnormal metabolite in the brain may produce the addictive state caused by alcoholic beverages.  相似文献   

Infants' discrimination of the duration of a rapid spectrum change in nonspeech signals   总被引：1，自引：0，他引：1  

P W Jusczyk  D B Pisoni  M A Reed  A Fernald  M Myers 《Science (New York, N.Y.)》1983,222(4620):175-177

Two-month-old infants discriminated complex sinusoidal patterns that varied in the duration of their initial frequency transitions. Discrimination of these nonspeech sinusoidal patterns was a function of both the duration of the transitions and the total duration of the stimulus pattern. This contextual effect was observed even though the information specifying stimulus duration occurred after the transitional information. These findings parallel those observed with infants for perception of synthetic speech stimuli. Specialized speech processing capacities are thus not required to account for infants' sensitivity to contextual effects in acoustic signals, whether speech or nonspeech.  相似文献   

An expanded approach to the problem of disappearing species     

Myers N 《Science (New York, N.Y.)》1976,193(4249):198-202

Assistance for disappearing species is at present too localized and dispersed to make much impact on the problem with its growing dimensions. Species are threatened primarily because of their status as common property. Institutional deficiencies, notably those of free markets and property rights, promote depletion of species. Conversely, present institutional mechanisms offer little scope for society to express its preferences for goods without price or to establish responsibility for common-heritage resources. The situation postulates corrective measures on the part of collective authority at the international level. These measures would require a joint commitment by the developed and developing worlds, on a scale to reflect the increasingly interdependent needs and opportunities of the community at large. Whether the community perceives itself as a community or not, it functions as such in many of its ecological relationships and economic interactions. The community will sooner or later be obliged to respond to the problem of vanishing species: either sooner, through protective measures of sufficient scope, or later, when it finds that the disappearance of large numbers of species represents a loss through which it is indivisibly impoverished.  相似文献   

Radiation hybrid mapping: a somatic cell genetic method for constructing high-resolution maps of mammalian chromosomes   总被引：69，自引：0，他引：69  

D R Cox  M Burmeister  E R Price  S Kim  R M Myers 《Science (New York, N.Y.)》1990,250(4978):245-250

Radiation hybrid (RH) mapping, a somatic cell genetic technique, was developed as a general approach for constructing long-range maps of mammalian chromosomes. This statistical method depends on x-ray breakage of chromosomes to determine the distances between DNA markers, as well as their order on the chromosome. In addition, the method allows the relative likelihoods of alternative marker orders to be determined. The RH procedure was used to map 14 DNA probes from a region of human chromosome 21 spanning 20 megabase pairs. The map was confirmed by pulsed-field gel electrophoretic analysis. The results demonstrate the effectiveness of RH mapping for constructing high-resolution, contiguous maps of mammalian chromosomes.  相似文献   

A High-Temperature Electrical Conduction Mechanism in the Lower Mantle Phase (Mg,Fe)1-xO     

DP Dobson  NC Richmond  JP Brodholt 《Science (New York, N.Y.)》1997,275(5307):1779-1781

Measurements of electrical conductivity at high pressure and temperature were taken on the lower mantle phase magnesiowustite with varying Fe3+ content. Although previous measurements at atmospheric pressure suggest Fe2+-Fe3+ hopping (small polaron) as the dominant conductivity mechanism, the present experiments show a change in charge transport mechanism with temperature. The lower temperature measurements are consistent with small polaron conduction, but at higher temperatures, which are more applicable to the lower mantle, a large polaron mechanism is suggested. Because these mechanisms have different temperature and compositional dependencies, this transition has important implications for extrapolation to mantle conditions.  相似文献   

Altered response to pneumococcal polysaccharide in offspring of immunologically paralyzed mice   总被引：3，自引：0，他引：3  

R Kerman  D Segre  W L Myers 《Science (New York, N.Y.)》1967,156(781):1514-1516

The dose of pneumococcal polysaccharide type III required to induce immunologic paralysis in newborn offspring of immunologically paralyzed mice was one-tenth of the corresponding paralyzing dose for newborn offspring of normal mice. Similarly, immunization of the offsprinig of the paralyzed mice was accomplished with one-tenth the dose of polysaccharide necessary to immunize normal newborn mice. The altered susceptibility of newborn mice from paralyzed mothers to the induction of both paralysis and immunity was predicted from theories of antibody formation which postulate that the induction of tolerance or immunity is controlled by the concentration of natural antibodies specific for the antigen used.  相似文献   

Navy F-14: New Fighter's Cost, Sophistication, Stir Controversy     

Myers HR 《Science (New York, N.Y.)》1972,176(4030):35-37

  相似文献   

Who fights in little wars?     

Myers JM 《Science (New York, N.Y.)》1967,156(3778):1035

  相似文献   

Regulation of blood and lymphatic vascular separation by signaling proteins SLP-76 and Syk     

Abtahian F  Guerriero A  Sebzda E  Lu MM  Zhou R  Mocsai A  Myers EE  Huang B  Jackson DG  Ferrari VA  Tybulewicz V  Lowell CA  Lepore JJ  Koretzky GA  Kahn ML 《Science (New York, N.Y.)》2003,299(5604):247-251

Lymphatic vessels develop from specialized endothelial cells in preexisting blood vessels, but the molecular signals that regulate this separation are unknown. Here we identify a failure to separate emerging lymphatic vessels from blood vessels in mice lacking the hematopoietic signaling protein SLP-76 or Syk. Blood-lymphatic connections lead to embryonic hemorrhage and arteriovenous shunting. Expression of slp-76 could not be detected in endothelial cells, and blood-filled lymphatics also arose in wild-type mice reconstituted with SLP-76-deficient bone marrow. These studies reveal a hematopoietic signaling pathway required for separation of the two major vascular networks in mammals.  相似文献