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1.
It is well known that Frege's system in the Grundgesetze der Arithmetik is formally inconsistent. Frege's instantiation rule for the second-order universal quantifier makes his system, except for minor differences, full (i.e., with unrestricted comprehension) second-order logic, augmented by an abstraction operator that abides to Frege's basic law V. A few years ago, Richard Heck proved the consistency of the fragment of Frege's theory obtained by restricting the comprehension schema to predicative formulae. He further conjectured that the more encompassing 1 1-comprehension schema would already be inconsistent. In the present paper, we show that this is not the case.  相似文献   
2.
The effects of a carefully monitored and increased police patrol on the report of crime were examined in four patrol zones. Overall patrol movement was increased to four times normal levels and slow patrol movement (under 20 mph) to around 30 times normal levels for 10 days. The patrol was active in two zones between 9:00 a.m. and 5:00 p.m. and in the other two zones between 7:00 p.m. and 3:00 a.m. A multiple-baseline design and time-series statistical analyses showed statistically reliable changes in reported levels of Part I crime (such as robbery, burglary, and aggravated assault) during both night patrols, but not in the day patrols. In both night-patrol zones, there were also reliable increases from saturation patrol to postsaturation patrol in report of Part I crime after the night patrol was terminated. Neither of the day patrols showed significant crime report changes on termination. Despite statistically reliable decreases in report of crime during nighttime hours, the value of saturation patrolling as a crime-prevention technique was questioned on cost/benefit grounds.  相似文献   
3.
在无痛胃镜检查中观察并比较等效剂量瑞芬太尼和芬太尼血流动力学指标、氧饱和度的影响以及不良反应的发生率。择期无痛胃镜检查ASAⅠ级~Ⅱ级的患者90例,随机分为丙泊酚+芬太尼组(PF组,n=40)和丙泊酚+瑞芬太尼组(PR组,n=50),记录患者睫毛反射消失时间、胃镜操作时间、苏醒时间以及用药前(T1)、睫毛反射消失时(T2)、胃镜过咽喉部时(T3)、胃镜退出时(T4)、苏醒时(T5)等时点血流动力学指标和氧饱和度。结果两组患者较术前都有明显的血压下降,PR组窦性心动过缓20例(40.8%)、PF组8例(20.0%),PR组窦性心动过缓发生率明显增加(P〈0.05)。用于无痛胃镜检查麻醉时,瑞芬太尼不良反应较多,芬太尼相对更为安全。  相似文献   
4.
Piéron's Law describes the relationship between stimulus intensity and reaction time. Previously (Stafford & Gurney, 2004), we have shown that Piéron's Law is a necessary consequence of rise-to-threshold decision making and thus will arise from optimal simple decision-making algorithms (e.g., Bogacz, Brown, Moehlis, Holmes, & Cohen, 2006). Here, we manipulate the color saturation of a Stroop stimulus. Our results show that Piéron's Law holds for color intensity and color-naming reaction time, extending the domain of this law, in line with our suggestion of the generality of the processes that can give rise to Piéron's Law. In addition, we find that Stroop condition does not interact with the effect of color saturation; Stroop interference and facilitation remain constant at all levels of color saturation. An analysis demonstrates that this result cannot be accounted for by single-stage decision-making algorithms which combine all the evidence pertaining to a decision into a common metric. This shows that human decision making is not information-optimal and suggests that the generalization of current models of simple perceptual decision making to more complex decisions is not straightforward.  相似文献   
5.
This paper extends Parikh’s earlier work in semantics with games of partial information and attempts to derive and represent the full content of an utterance from first principles. It also discusses various ways in which this content may be indeterminate.  相似文献   
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7.
Scholars and political consultants alike know that during a campaign even the hint of a scandal has the potential to distract from a candidate's policy messages—or even worse—can have dire consequences on Election Day. But does it matter whether the scandal breaks early as opposed to late in the campaign? And how do citizens respond when the scandal drags on for weeks? This study represents the first effort to shed light on these temporal dynamics. Results reveal that timing affects the immediate impact of scandal information, the rate at which those initial effects decay, and candidate evaluations offered at the campaign's conclusion. Additionally, I develop two competing hypotheses regarding how citizens may process scandal information when it is repeated throughout a campaign. Empirical tests suggest that voters eventually reach a saturation threshold after which additional repetition of scandal information has negligible effects on evaluations unless new details are a prominent feature of ongoing coverage, in which case repetition can extend the negative effects of scandal.  相似文献   
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9.
Justice‐involved people vary substantially in their risk of reoffending. To date, recidivism prediction and prevention efforts have largely focused on individual‐level factors like antisocial traits. Although a growing body of research has examined the role of residential contexts in predicting reoffending, results have been equivocal. One reason for mixed results may be that an individual’s susceptibility to contextual influence depends upon his or her accumulated risk of reoffending. Based on a sample of 2218 people on probation in San Francisco, California, this study draws on observational and secondary data to test the hypothesis that individual risk moderates the effect of neighborhood factors on recidivism. Results from survival analyses indicate that individual risk interacts with neighborhood concentrated disadvantage and disorder—and these factors increase recidivism among people relatively low in individual risk, but not those at higher risk. This is consistent with the disadvantage saturation perspective, raising the possibility that some people classified as low risk might not recidivate but for placement in disadvantaged and disorderly neighborhoods. Ultimately, residential contexts “matter” for lower risk people and may be useful to consider in efforts to prevent recidivism.  相似文献   
10.
Three experiments used similar methods to investigate the pigeon's perception of saturation of monochromatic lights. This trial-wise procedure consisted of brief presentations of positive and negative stimuli in random sequence. Pecks to the positive stimuli were occasionally reinforced on a low fixed-ratio schedule. The first study determined absolute thresholds for "white" and monochromatic lights by establishing a discrimination between lights of various radiances and a dark key. Experiment II investigated generalization from a white light to various monochromatic lights under conditions that minimized the use of luminance as a cue. The third experiment examined discrimination of various monochromatic lights along a colorimetric purity continuum; responses to white light were reinforced, while responses to lights that combined white and monochromatic lights in various proportions were not. The results indicated that lights of different wavelength differ in saturation, but that all are discriminable from white. Wavelengths between 550 and 600 nm are least saturated for the pigeon, and saturation increases markedly as wavelength decreases below this region of the spectrum.  相似文献   
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