The limits of counting: numerical cognition between evolution and culture     

Beller S  Bender A 《Science (New York, N.Y.)》2008,319(5860):213-215

Number words that, in principle, allow all kinds of objects to be counted ad infinitum are one basic requirement for complex numerical cognition. Accordingly, short or object-specific counting sequences in a language are often regarded as earlier steps in the evolution from premathematical conceptions to greater abstraction. We present some instances from Melanesia and Polynesia, whose short or object-specific sequences originated from the same extensive and abstract sequence. Furthermore, the object-specific sequences can be shown to be cognitively advantageous for calculations without notation because they use larger counting units, thereby abbreviating higher numbers, enhancing the counting process, and extending the limits of counting. These results expand our knowledge both regarding numerical cognition and regarding the evolution of numeration systems.  相似文献   

Molecular Genetics of the Bithorax Complex in Drosophila melanogaster     

Bender W  Akam M  Karch F  Beachy PA  Peifer M  Spierer P  Lewis EB  Hogness DS 《Science (New York, N.Y.)》1983,221(4605):23-29

The bithorax complex in Drosophila melanogaster is a cluster of homeotic genes that specify developmental pathways for many of the body segments of the fly. The DNA of the bithorax complex has been isolated, and a region of 195,000 base pairs that covers the left half of the complex is described here. The lesions associated with many of the bithorax complex mutants have been identified, and most are due to DNA rearrangements. Most of the spontaneous mutants have insertions of a particular mobile element named "gypsy." This element affects the functions of sequences removed from the site of insertion. Mutant lesions for a given phenotypic class are distributed over large DNA distances of up to 73,000 base pairs.  相似文献   

Radar detection of the nucleus and coma of comet hyakutake     

JK Harmon  SJ Ostro  LAM Benner  KD Rosema  RF Jurgens  R Winkler  DK Yeomans  D Choate  R Cormier  JD Giorgini  DL Mitchell  PW Chodas  R Rose  D Kelley  MA Slade  ML Thomas 《Science (New York, N.Y.)》1997,278(5345):1921-1924

Radar observations of comet Hyakutake (C/1996 B2) made at the Goldstone Deep Space Communications Complex in California have detected echoes from the nucleus and from large grains in the inner coma. The nucleus of this bright comet was estimated to be only 2 to 3 kilometers in diameter. Models of the coma echo indicate backscatter from porous, centimeter-size grains ejected anisotropically at velocities of tens of meters per second. The radar observations suggest that a comet's activity may be a poor indicator of its size and provide evidence that large grains constitute an important component of the mass loss from a typical active comet.  相似文献   

Differential expression of c-myb mRNA in murine B lymphomas by a block to transcription elongation   总被引：49，自引：0，他引：49  

T P Bender  C B Thompson  W M Kuehl 《Science (New York, N.Y.)》1987,237(4821):1473-1476

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Detection of papillomavirus DNA in human semen   总被引：10，自引：0，他引：10  

R S Ostrow  K R Zachow  M Niimura  T Okagaki  S Muller  M Bender  A J Faras 《Science (New York, N.Y.)》1986,231(4739):731-733

Human papillomavirus DNA has been detected in the semen of three patients, two of whom have severe chronic wart disease. These data support the contention that sexual transmission of human papillomavirus DNA could occur via semen, a possibility suggested by epidemiological data on the sexual transmission of human papillomavirus.  相似文献   

Components of rust resistance in lentil     

T. Negussie  Z. A. Pretorius  C. M. Bender 《Euphytica》2005,142(1-2):55-64

Four components of resistance to Uromyces viciae-fabae, namely, latent period (LP), infection efficiency (IE), pustule size (PS) and spore production (SP) were evaluated on lentil (Lens culinaris) in glasshouse experiments. Four cultivars, Gudo, R-186, FLIP-87-66L and FLIP-89-60L, with different levels of resistance, and the susceptible check EL-142, were included in this study. The cultivars were also compared for area under the disease progress curve (AUDPC), area under the pustule density curve (APDC), apparent infection rate (r_G), disease severity (DS), pustule density (PD), LP and PS under field conditions. Gudo and R-186 had significantly smaller and fewer pustules, lower spore yield and longer latent period than EL-142. FLIP-87-66L was intermediate for infection efficiency and pustule size. In addition, significant differences were found between cultivars for AUDPC, APDC, DS and r_G. Estimates of AUDPC, APDC, DS and r_G were reduced in Gudo, R-186 and FLIP-87-66L compared with the susceptible check EL-142. FLIP-89-60L also showed low AUDPC, APDC and DS. Some of the components obtained in the field were significantly correlated with each other (r = 0.92–0.99, P 0.05) and those measured in the glasshouse. Most of the components studied in the glasshouse were significantly (P 0.05) correlated with AUDPC and DS. Data indicated the existence of incomplete [partial (PR)] resistance in the test cultivars, and the possibility of using IE, LP, SP and PS as selection criteria in the evaluation of PR to rust in lentil. Since there was an interdependence of the components, selection based on more than one component should help obtain lines with higher levels of PR. The AUDPC, DS and r_G could also be used for selecting lines with PR in the field.  相似文献   

Long-term radiographic appearance of a bioabsorbable biocomposite tibial tuberosity advancement cage implant     

CL Ferrell  MD Barnhart  AT Watson  ML Barron-Chapman  SJ Naber 《Australian veterinary journal》2020,98(1-2):26-30

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Fish feeds from grass clippings     

Judith A. Bender  Yupha Vatcharapijarn  Arturo Russell 《Aquacultural Engineering》1989,8(6):407-419

The objective of this research was to develop a quality fish feed that could be produced from simple plant material by way of microbial processing. Silaged grass clippings, applied to shallow ponds, produced floating mats of microbial biomass containing 26% protein and 43% carbohydrate in 7–10 days. The final silage-microbe mat (SMM) showed increases of over 300% in biomass and 100% in protein content over the silage feedstock. Productivity and microbial succession patterns were similar in laboratory ponds and tropical field ponds located in the Dominican Republic. In laboratory experiments SMM-fed tilapia, Oreochromis niloticus, showed significant growth increases over controls (fed commercial catfish fish feed), if they were allowed to graze the SMM together with the gelatinous detrital deposited during SMM culture. SMM produced little fish growth if it was harvested and fed separately in clean-bottom ponds without detrital buildup. These data show that the microbial mat produced from processed grass clippings can produce a nutritious natural fish food in the pond. The detrital trophic level in the sediment (stimulated by SMM culture), is a critical component in this diet.  相似文献   

Radiogaschromatographie von Kohlenhydraten,Organischen Säuren und Aminosäuren aus Pflanzen     

C. Pertzsch  L. Bender  K. -H. Neumann 《植物养料与土壤学杂志》1981,144(3):231-240

Radio gaschromatography of carbohydrates, organic acids and amino acids A method for the radio-gaschromatographic determination of carbohydrates, organic acids and amino acids as well as the simultaneous recording of the specific activity of radioactive labelled compounds of these fractions is described and its application to the analysis of plant extracts or protein hydrolysates demonstrated. The application of 0.05–0.1 mCi ¹⁴C/g fresh weight of plant material is enough to obtain a sufficiently strong labelling even in short-term incubation experiments (15 sec.), as for example in photosynthesis research.  相似文献   

Anthelmintic resistance in Australian sheep nematode populations   总被引：2，自引：0，他引：2  

DJ OVEREND †  ML PHILLIPS  AL POULTON†  CED FOSTER† 《Australian veterinary journal》1994,71(4):117-121

SUMMARY The resistance status of gastro–intestinal nematodes to anthelmintics was evaluated on 881 sheep farms throughout Australia during 1991–92. Resistance was shown to be widespread. Overall, 85% of farms had sheep infected with nematodes resistant to benzimidazole, 65% to levamisole and 34% to combination (benzimidazole + levamisole) products. Resistance to ivermectin was not detcted. On only 9% of farms did all anthelmintic groups reduce egg counts by greater than or equal to 95%. The culture of faeces from untreated sheep showed Telodorsagia circumcincta, Trichostrongylus spp, Chabertia ovina and Haemonchus contortus to be the principal species. The nature and prevalence of resistance was not significantly correlated with stocking rate. However, resistance to combination products was almost twice as prevalent on farms in areas with an average annual rainfall of greater than 500 mm.  相似文献