Transport of Dissolved Amino Acids by the Mussel, Mytilus edulis: Demonstration of Net Uptake from Natural Seawater     

Manahan DT  Wright SH  Stephens GC  Rice MA 《Science (New York, N.Y.)》1982,215(4537):1253-1255

High-performance liquid chromatography provides direct evidence for substantial removal of naturally occurring specific free amino acids during a single passage of water through the mantle cavity of mussels. This occurs during the few seconds required for passage of the water across the gill, and removal proceeds unabated at ambient substrate concentrations as low as 38 nanomoles per liter.  相似文献   

施肥对稻米品质和产量影响的研究   总被引：7，自引：0，他引：7  

周瑞庆 《湖南农业大学学报(自然科学版)》1989,(3)

通过1985～1087年的多点田间试验和盆栽试验,探索了施氮量,施氮时期,氮、磷、钾三要素及其组合方式,基肥种类以及稀土微肥对稻米产量和品质的影响,为优质稻合理施肥提供了理论依据。  相似文献   

Virginia barrier island configuration: a reappraisal     

Leatherman SP  Rice TE  Goldsmith V 《Science (New York, N.Y.)》1982,215(4530):285-287

The 12 Virginia barrier islands are divided into three groups on the basis of historical retreat rates and characteristics. The growth and reversal of inlet offsets is a long-term event that results from the operation of known coastal processes. Both geomorphic evidence and wave refraction analyses indicate that shoreline irregularity will diminish with time. There is no basis for the prediction (or expectation) that cape-like features will evolve along this shoreline.  相似文献   

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   

A Burkholderia pseudomallei toxin inhibits helicase activity of translation factor eIF4A     

Cruz-Migoni A  Hautbergue GM  Artymiuk PJ  Baker PJ  Bokori-Brown M  Chang CT  Dickman MJ  Essex-Lopresti A  Harding SV  Mahadi NM  Marshall LE  Mobbs GW  Mohamed R  Nathan S  Ngugi SA  Ong C  Ooi WF  Partridge LJ  Phillips HL  Raih MF  Ruzheinikov S  Sarkar-Tyson M  Sedelnikova SE  Smither SJ  Tan P  Titball RW  Wilson SA  Rice DW 《Science (New York, N.Y.)》2011,334(6057):821-824

The structure of BPSL1549, a protein of unknown function from Burkholderia pseudomallei, reveals a similarity to Escherichia coli cytotoxic necrotizing factor 1. We found that BPSL1549 acted as a potent cytotoxin against eukaryotic cells and was lethal when administered to mice. Expression levels of bpsl1549 correlate with conditions expected to promote or suppress pathogenicity. BPSL1549 promotes deamidation of glutamine-339 of the translation initiation factor eIF4A, abolishing its helicase activity and inhibiting translation. We propose to name BPSL1549 Burkholderia lethal factor 1.  相似文献   

Impact on discharge monitoring of recent epa initiatives in water quality measurement     

R. F. Maddalone  J. W. Scott  J. K. Rice  B. R. Nott 《Water, air, and soil pollution》1996,90(1-2):245-255

Human health and aquatic life requirements can result in the establishment of effluent limitations on power plant aqueous discharges that are below the quantitation and even the detection capability of many of the current sampling and analytical procedures. To meet this situation for compliance monitoring, EPA has developed analytical methods that reportedly lower detection and quantitation levels by one to two orders of magnitude. Procedures to develop appropriate statistically-based detection and quantitation estimates for these methods are being developed by the Electric Power Research Institute (EPRI) and other industry and regulatory groups. EPA is also in the process of developing guidelines for performance based methods, which they believe will encourage innovation and speed the process of bringing new methods into use. This paper will discuss the impact of these proposed changes on the end user.  相似文献   

Fumonisin B1 concentrations in feeds from 45 confirmed equine leukoencephalomalacia cases   总被引：1，自引：0，他引：1  

P F Ross  L G Rice  J C Reagor  G D Osweiler  T M Wilson  H A Nelson  D L Owens  R D Plattner  K A Harlin  J L Richard 《Journal of veterinary diagnostic investigation》1991,3(3):238-241

During the fall of 1989 and winter of 1990, numerous reports of equine leukoencephalomalacia (ELEM) occurred from many regions of the United States. Typically, horses were consuming feed partially or entirely composed of corn and/or corn screenings. From October 1989 through May 1990, samples from 55 confirmed or suspected ELEM cases were received at the National Veterinary Services Laboratories, Ames, Iowa, for fumonisin B1 analysis. Samples from 9 cases in 1984-1985 were also obtained. Fumonisin B1, a mycotoxin produced by Fusarium moniliforme, causes ELEM, but little is known of naturally occurring toxic or safe levels in feeds. To determine what levels of fumonisin B1 in feeds are associated with ELEM, 45 selected cases were studied. The fumonisin B1 concentrations ranged from less than 1 ppm to 126 ppm, with the majority of the samples above 10 ppm. All types of feeds were included: corn, screenings, sweet feeds, and commercially pelleted rations. The length of exposure varied from 7 to greater than 35 days. Horse feed samples not associated with ELEM were also collected and analyzed. None of the nonproblem feed samples contained fumonisin B1 levels greater than 8 ppm.  相似文献   

Role of blackflies in the epidemiology of Potomac horse fever     

N E Hahn  B D Perry  R M Rice  J W Hansen  E C Turner 《The Veterinary record》1989,125(10):273-274

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Effects of diet on fecal occult blood testing in healthy dogs.          下载免费PDF全文

J E Rice  S L Ihle 《Canadian journal of veterinary research》1994,58(2):134-137

Six dogs were fed each of nine diets to evaluate the effects of diet on fecal occult blood test results. The diets represented a range of different type (i.e. canned, dry or semi-moist), protein and vegetable constituents, and fiber contents. Each diet was fed twice daily for five consecutive days; fecal samples were collected twice daily on days 4 and 5. An o-tolidine test kit and a guaiac paper test kit for fecal occult blood were used. Two hundred and sixteen fecal samples were analyzed (24 samples/diet). When using the guaiac test the following positive results were obtained from fecal samples from dogs consuming a canned meat- and vegetable-based diet (24/24 samples); a canned meat-based diet (24/24 samples); a dry corn and poultry-based diet (9/24 samples); a dry corn, wheat, and meat meal diet (4/24 samples), a canned poultry-based diet (1/24 sample) and a semi-moist soybean meal-based diet (2/24 samples). A total of 64 samples were positive using the guaiac test. Using the o-tolidine test, no samples were positive. The difference between the number of positive results with each test kit was highly significant (p < 0.001). Results indicate that 1) diet affects the specificity of guaiac test fecal occult blood results in the dog and 2) positive o-tolidine test results were not caused by diets fed in the study.  相似文献   

Response of susceptible and resistant peach-potato aphids Myzus persicae (Sulz.) to insecticides in leaf-dip bioassays     

Roman M. Sawicki  Adrian D. Rice 《Pest management science》1978,9(6):513-516

The response of susceptible (S), moderately resistant (R₁) and strongly resistant (R₂) peach-potato aphids, Myzus persicae (Sulz.) to organophosphorus, carbamate and pyrethroid insecticides was tested by a leaf-dip bioassay. The aphids were placed on potato leaves (dipped in insecticide solutions 1–2 or 24 h before infestation) and their mortality examined 48 h later. R₁ aphids were virtually susceptible to most of the carbamates, demephion and acephate, but were slightly to moderately resistant (2.1–9.4 times) to permethrin, cypermethrin and (S)-α-cyano-3-phenoxybenzyl (1R)-cis-3-(2,2-dibromovinyl)-2,2-dimethylcyclopropanecarboxylate (I), (NRDC 161), to 5,6,7,8-tetrahydro-2-methylquinolin-4-yl dimethylcarbamate (II), (Hoechst 25 682) and demeton-S-methyl. R₂ aphids resisted more strongly or very strongly (between 65 and 1280 times) the pyrethroids, demeton-S-methyl (×94), II (×83) and demephion (×9), and were slightly to moderately (2–5 times) resistant to acephate, pirimicarb, ethiofencarb and 2-(dimethylcarbamoyloxyimino)-3-methoxyimino-N,N- dimethylbutyramide (III), (DPX 3853). Both resistant strains were susceptible to nitrilacarb [4,4-dimethyl-5-(methylcarbamoyloxyimino)pentanenitrile] complex (1:1) with zinc chloride (IV), (AC 85 258). The implications of these results in terms of practical aphid control are discussed.  相似文献