Dental research: the past two decades. National Institute of Dental Research interdisciplinary programs have broadened the base of dental science     

A L Morris  R C Greulich 《Science (New York, N.Y.)》1968,160(832):1081-1088

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Cementum annuli in mammal teeth from archeological sites     

Bourque BJ  Morris K  Spiess A 《Science (New York, N.Y.)》1978,202(4367):542

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Language discrimination by human newborns and by cotton-top tamarin monkeys     

Ramus F  Hauser MD  Miller C  Morris D  Mehler J 《Science (New York, N.Y.)》2000,288(5464):349-351

Humans, but no other animal, make meaningful use of spoken language. What is unclear, however, is whether this capacity depends on a unique constellation of perceptual and neurobiological mechanisms or whether a subset of such mechanisms is shared with other organisms. To explore this problem, parallel experiments were conducted on human newborns and cotton-top tamarin monkeys to assess their ability to discriminate unfamiliar languages. A habituation-dishabituation procedure was used to show that human newborns and tamarins can discriminate sentences from Dutch and Japanese but not if the sentences are played backward. Moreover, the cues for discrimination are not present in backward speech. This suggests that the human newborns' tuning to certain properties of speech relies on general processes of the primate auditory system.  相似文献   

Oxalate Content of Tropical Forage Grasses     

Garcia-Rivera J  Morris MP 《Science (New York, N.Y.)》1955,122(3179):1089-1090

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Response     

Morris CE  Horn R 《Science (New York, N.Y.)》1991,253(5021):801

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Environment. Environmental monitoring network for India     

Sundareshwar PV  Murtugudde R  Srinivasan G  Singh S  Ramesh KJ  Ramesh R  Verma SB  Agarwal D  Baldocchi D  Baru CK  Baruah KK  Chowdhury GR  Dadhwal VK  Dutt CB  Fuentes J  Gupta PK  Hargrove WW  Howard M  Jha CS  Lal S  Michener WK  Mitra AP  Morris JT  Myneni RR  Naja M  Nemani R  Purvaja R  Raha S  Vanan SK  Sharma M  Subramaniam A  Sukumar R  Twilley RR  Zimmerman PR 《Science (New York, N.Y.)》2007,316(5822):204-205

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Astronomy. Glimpsing matter at the brink     

Morris MR 《Science (New York, N.Y.)》2004,304(5671):689-692

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Pyroclastic activity at Home Plate in Gusev Crater, Mars     

Squyres SW  Aharonson O  Clark BC  Cohen BA  Crumpler L  de Souza PA  Farrand WH  Gellert R  Grant J  Grotzinger JP  Haldemann AF  Johnson JR  Klingelhöfer G  Lewis KW  Li R  McCoy T  McEwen AS  McSween HY  Ming DW  Moore JM  Morris RV  Parker TJ  Rice JW  Ruff S  Schmidt M  Schröder C  Soderblom LA  Yen A 《Science (New York, N.Y.)》2007,316(5825):738-742

Home Plate is a layered plateau in Gusev crater on Mars. It is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. A coarsegrained lower unit lies under a finer-grained upper unit. Textural observations indicate that the lower strata were emplaced in an explosive event, and geochemical considerations favor an explosive volcanic origin over an impact origin. The lower unit likely represents accumulation of pyroclastic materials, whereas the upper unit may represent eolian reworking of the same pyroclastic materials.  相似文献   

Coal conversion technologies: some health and environmental effects     

Morris SC  Moskowitz PD  Sevian WA  Silberstein S  Hamilton LD 《Science (New York, N.Y.)》1979,206(4419):654-662

Several technologies to convert coal to liquid and gaseous fuels are being developed in the United States, some with support from the Department of Energy. Substitution of these technologies for those currently being used will produce different health and environmental hazards. In this article, selected health and environmental effects of four coal conversion and four existing technologies are compared. For each technology, the emission estimates for complete fuel cycles, including all steps in fuel use from extraction to the end use of space and water heating by electricity or direct combustion, were prepared by means of the Brookhaven Energy System Network Simulator model. Quantitative occupational health and safety estimates are presented for the extraction, transportation, distribution, processing, and conversion activities associated with each technology; also included are some public health damage estimates arising from fuel transportation and air pollution impacts. Qualitative estimates of health damage due to polycyclic organic matter and reduced sulfur are discussed. In general, energy inefficiencies, environmental residuals, and hence implied environmental effects and health damage increase in the order: (i) direct combustion of natural gas and oil, (ii) direct combustion of synthetic gas and oil, (iii) central-station electric power produced from synthetic gas, (iv) central-station electric power produced from coal, and (v) central-station electric power produced by the combustion of synthetic liquid fuels. The compliance and conflict of these technologies with the amendments of the Clean Air Act and other legislation are discussed.  相似文献   

A synthetic nickel electrocatalyst with a turnover frequency above 100,000 s⁻¹ for H₂ production     

Helm ML  Stewart MP  Bullock RM  DuBois MR  DuBois DL 《Science (New York, N.Y.)》2011,333(6044):863-866

Reduction of acids to molecular hydrogen as a means of storing energy is catalyzed by platinum, but its low abundance and high cost are problematic. Precisely controlled delivery of protons is critical in hydrogenase enzymes in nature that catalyze hydrogen (H(2)) production using earth-abundant metals (iron and nickel). Here, we report that a synthetic nickel complex, [Ni(P(Ph)(2)N(Ph))(2)](BF(4))(2), (P(Ph)(2)N(Ph) = 1,3,6-triphenyl-1-aza-3,6-diphosphacycloheptane), catalyzes the production of H(2) using protonated dimethylformamide as the proton source, with turnover frequencies of 33,000 per second (s(-1)) in dry acetonitrile and 106,000 s(-1) in the presence of 1.2 M of water, at a potential of -1.13 volt (versus the ferrocenium/ferrocene couple). The mechanistic implications of these remarkably fast catalysts point to a key role of pendant amines that function as proton relays.  相似文献