The landslide hazard in the San Francisco Bay region     

Earl E. Brabb 《Water, air, and soil pollution》1977,7(2):237-238

Development in hilly or mountainous terrain has resulted in much landslide damage. Areas susceptible to landsliding can be recognized. Practices for minimizing landslides are presented.  相似文献   

Identification of the fusion peptide of primate immunodeficiency viruses   总被引：48，自引：0，他引：48  

M L Bosch  P L Earl  K Fargnoli  S Picciafuoco  F Giombini  F Wong-Staal  G Franchini 《Science (New York, N.Y.)》1989,244(4905):694-697

Membrane fusion induced by the envelope glycoproteins of human and simian immunodeficiency viruses (HIV and SIVmac) is a necessary step for the infection of CD4 cells and for the formation of syncytia after infection. Identification of the region in these molecules that mediates the fusion events is important for understanding and possibly interfering with HIV/SIVmac infection and pathogenesis. Amino acid substitutions were made in the 15 NH2-terminal residues of the SIVmac gp32 transmembrane glycoprotein, and the mutants were expressed in recombinant vaccinia viruses, which were then used to infect CD4-expressing T cell lines. Mutations that increased the overall hydrophobicity of the gp32 NH2-terminus increased the ability of the viral envelope to induce syncytia formation, whereas introduction of polar or charged amino acids in the same region abolished the fusogenic function of the viral envelope. Hydrophobicity in the NH2-terminal region of gp32 may therefore be an important correlate of viral virulence in vivo and could perhaps be exploited to generate a more effective animal model for the study of acquired immunodeficiency syndrome.  相似文献   

V1 neurons signal acquisition of an internal representation of stimulus location     

Sharma J  Dragoi V  Tenenbaum JB  Miller EK  Sur M 《Science (New York, N.Y.)》2003,300(5626):1758-1763

A fundamental aspect of visuomotor behavior is deciding where to look or move next. Under certain conditions, the brain constructs an internal representation of stimulus location on the basis of previous knowledge and uses it to move the eyes or to make other movements. Neuronal responses in primary visual cortex were modulated when such an internal representation was acquired: Responses to a stimulus were affected progressively by sequential presentation of the stimulus at one location but not when the location was varied randomly. Responses of individual neurons were spatially tuned for gaze direction and tracked the Bayesian probability of stimulus appearance. We propose that the representation arises in a distributed cortical network and is associated with systematic changes in response selectivity and dynamics at the earliest stages of cortical visual processing.  相似文献   

Rebuttal: Disturbance to Surface Lithic Components of Archaeological Sites by Drill Seeding     

Jeffrey A. Rust  Dale. Earl 《Strength and Conditioning Journal》2011,64(5):548-551

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Letter to the editor     

C. Arden Pope  Earl O. Heady 《Agricultural Systems》1983,11(4):255-257

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Butterflies and woodlands in Britain     

C.F. Mason  T.G. Shreeve  Earl D. McCoy 《Biological conservation》1984,28(4):377-379

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Pharmacokinetics and pharmacodynamics of enrofloxacin and a low dose of amikacin administered via regional intravenous limb perfusion in standing horses     

Parra-Sanchez A  Lugo J  Boothe DM  Gaughan EM  Hanson RR  Duran S  Belknap JK 《American journal of veterinary research》2006,67(10):1687-1695

OBJECTIVE: To evaluate the pharmacokinetic-pharmacodynamic parameters of enrofloxacin and a low dose of amikacin administered via regional IV limb perfusion (RILP) in standing horses. ANIMALS: 14 adult horses. PROCEDURES: Standing horses (7 horses/group) received either enrofloxacin (1.5 mg/kg) or amikacin (250 mg) via RILP (involving tourniquet application) in 1 forelimb. Samples of interstitial fluid (collected via implanted capillary ultrafiltration devices) from the bone marrow (BMIF) of the third metacarpal bone and overlying subcutaneous tissues (STIF), blood, and synovial fluid of the radiocarpal joint were collected prior to (time 0) and at intervals after tourniquet release for determination of drug concentrations. For pharmacokinetic-pharmacodynamic analyses, minimum inhibitory concentrations (MICs) of 16 microg/mL (amikacin) and 0.5 microg/mL (enrofloxacin) were applied. RESULTS: After RILP with enrofloxacin, 3 horses developed vasculitis. The highest synovial fluid concentrations of enrofloxacin and amikacin were detected at time 0; median values (range) were 13.22 microg/mL (0.254 to 167.9 microg/mL) and 26.2 microg/mL (5.78 to 50.0 microg/mL), respectively. Enrofloxacin concentrations exceeded MIC for approximately 24 hours in STIF and synovial fluid and for 36 hours in BMIF. After perfusion of amikacin, concentrations greater than the MIC were not detected in any samples. Effective therapeutic concentrations of enrofloxacin were attained in all samples. CONCLUSIONS AND CLINICAL RELEVANCE: In horses with orthopedic infections, RILP of enrofloxacin (1.5 mg/kg) should be considered as a treatment option. However, care must be taken during administration. A dose of amikacin > 250 mg is recommended to attain effective tissue concentrations via RILP in standing horses.  相似文献   

U.S. elections. Scientists urge Obama, Romney to address key S&T issues     

E Lane  B Ham 《Science (New York, N.Y.)》2012,337(6098):1059

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Vocalizations of the South African cliff swallow Hirundo spilodera     

R.A. Earlé 《African Zoology》2013,48(3):229-232

The vocalizations of both adult and juvenile South African cliff swallows Hirundo spilodera are described. This swallow has a large vocal repertoire considering that it is a highly colonial species, and at least seven distinctive calls are recognized. In chicks there is a gradual change in the food soliciting call and it develops into the contact call. Contact calls of both chicks and adult birds were individually recognizable.  相似文献   

Uptake and nutrient balance of nitrogen,sulfur, and boron for optimal canola production in eastern Canada     

Bao-Luo Ma  Zhiming Zheng  Joann K. Whalen  Claude Caldwell  Anne Vanasse  Denis Pageau  Peter Scott  Hugh Earl  Don L. Smith 《植物养料与土壤学杂志》2019,182(2):252-264

Balanced plant nutrition is essential to achieve high yields of canola (Brassica napus L.) and get the best economic return from applied fertilizers. A field study was conducted at nine site‐years across eastern Canada to investigate the effects of nitrogen (N), sulfur (S) and boron (B) fertilization on canola nutrient uptake, nutrient balance, and their relationship to canola yields. The factorial experiment consisted of four N rates of 0 (N0), 50 (N50), 100 (N100), and 150 (N150) kg ha^?1, two S rates of 0 (S0) and 20 (S20) kg ha^?1, and three B treatments of 0 (B0), 2 kg ha^?1 at preplant (B2.0P), and 0.5 kg B ha^?1 foliar‐applied at early flowering stage (B0.5F). Each site‐year used the same experimental design and assigned treatments in a randomized complete block design with four replications. Fertilizer S application greatly improved seed yields at six out of nine site‐years, and the highest N use efficiency was in the N150+S20 treatment. Sulfur application generally increased seed S concentration, seed S removal, and plant total S uptake, while B fertilization mainly elevated straw B concentration and content, with minimal effect on seed yields. At the early flowering stage, plant tissue S ranged from 2.2 to 6.6 mg S g^?1, but the N : S ratio was over or close to the critical value of 12 in the N150+S0 combination at five site‐years. On average across nine site‐years, canola reached a plateau yield of 3580 kg ha^?1 when plants contained 197 kg N ha^?1, 33 kg S ha^?1 and 200 g B ha^?1, with a seed B content of 60 g B ha^?1. The critical N, S, and B values identified in this work and their potential for a posteriori nutrient diagnosis of canola should be useful to validate fertilizer requirements for canola production in eastern Canada.  相似文献