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Summary 1-Tetrahydrocannabinol ( 1-THC) has been quantified directly in erythrocyte membranes from drug-treated mice using gas chromatography/mass spectrometry. Concentrations of approximately 6 ng 1-THC/mg membrane protein (10–5 M) were found when effects of the drug on behavior were prevalent. At these concentrations the drug produced a decrease in membrane order as measured by ESR.This work was supported by grants from the Medical Research Council, the Wellcome Trust and the E. P. Abraham Cephalosporin Trust  相似文献   
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Paton JJ  Belova MA  Morrison SE  Salzman CD 《Nature》2006,439(7078):865-870
Visual stimuli can acquire positive or negative value through their association with rewards and punishments, a process called reinforcement learning. Although we now know a great deal about how the brain analyses visual information, we know little about how visual representations become linked with values. To study this process, we turned to the amygdala, a brain structure implicated in reinforcement learning. We recorded the activity of individual amygdala neurons in monkeys while abstract images acquired either positive or negative value through conditioning. After monkeys had learned the initial associations, we reversed image value assignments. We examined neural responses in relation to these reversals in order to estimate the relative contribution to neural activity of the sensory properties of images and their conditioned values. Here we show that changes in the values of images modulate neural activity, and that this modulation occurs rapidly enough to account for, and correlates with, monkeys' learning. Furthermore, distinct populations of neurons encode the positive and negative values of visual stimuli. Behavioural and physiological responses to visual stimuli may therefore be based in part on the plastic representation of value provided by the amygdala.  相似文献   
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Preferential germline mutation of the paternal allele in retinoblastoma   总被引:19,自引:0,他引:19  
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Zusammenfassung Es wurde die Wirkung von Lokalanästhetika auf die Anhäufung von [3H]-Metaraminol im Vorhofmuskel und Vas deferens des Kaninchens untersucht. Die von Kokain hervorgerufene Hemmung der [3H]-Metaraminol-Akkumulation ist mindestens hundertmal stärker als diejenige nach Procain, Prilocain und Lidocain.

Supported by a grant-in-aid from the Medical Research Council of Canada. The author is indebted to Astra Pharmaceuticals (Canada) Ltd. for supplies of lidocaine hydrochloride and prilocaine hydrochloride.  相似文献   
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AB5 toxins are produced by pathogenic bacteria and consist of enzymatic A subunits that corrupt essential eukaryotic cell functions, and pentameric B subunits that mediate uptake into the target cell. AB5 toxins include the Shiga, cholera and pertussis toxins and a recently discovered fourth family, subtilase cytotoxin, which is produced by certain Shiga toxigenic strains of Escherichia coli. Here we show that the extreme cytotoxicity of this toxin for eukaryotic cells is due to a specific single-site cleavage of the essential endoplasmic reticulum chaperone BiP/GRP78. The A subunit is a subtilase-like serine protease; structural studies revealed an unusually deep active-site cleft, which accounts for its exquisite substrate specificity. A single amino-acid substitution in the BiP target site prevented cleavage, and co-expression of this resistant protein protected transfected cells against the toxin. BiP is a master regulator of endoplasmic reticulum function, and its cleavage by subtilase cytotoxin represents a previously unknown trigger for cell death.  相似文献   
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Closed‐door decisions may be defined as decisions in which the outcome is determined by a limited number of decision‐makers and where the process is shrouded in at least some secrecy. In this paper, we examine the use of betting markets to forecast one particular closed‐door decision: the election of the pope. Within the context of 500 years of papal election betting, we employ a unique dataset of betting on the 2013 papal election to investigate how new public information is incorporated into the betting odds. Our results suggest that the market was generally unable to incorporate effectively such information. We venture some possible explanations for our findings and offer suggestions for further research into the prediction and predictability of other ‘closed‐door’ decisions. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
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In this paper, we examine a relatively novel form of gambling, spread (or index) betting that overlaps with practices in conventional financial markets. In this form of betting, a number of bookmakers quote bid–offer spreads about the result of some future event. Bettors may buy (sell) at the top (bottom) end of a spread. We hypothesize that the existence of an outlying spread may provide uninformed traders with forecasting information that can be used to develop improved trading strategies. Using data from a popular spread betting market in the United Kingdom, we find that the price obtaining at the market mid‐point does indeed provide a better forecast of asset values than that implied in the outlying spread. We further show that this information can be used to develop trading strategies leading to returns that are consistently positive and superior to those from noise trading. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
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