数量认知和密度认知的关系

数量和密度认知的关系是数量认知研究的关键问题。相关研究在三个方面存在不足：首先, 先前实验研究缺乏对两种加工的有效操控和区分; 其次, 现有理论或认为“数量和密度加工完全独立”, 或认为“数量加工是对密度进行推论的结果”, 比较片面; 第三, 已有理论模型抽象, 不重视功能模块的解释。基于数量认知的多阶段加工特点, 未来研究可以讨论数量认知进行基于密度认知的整合加工的可能性, 提出整合数量和密度加工的理论构想。     

Impact of artificial fissioning and social networks on levels of aggression and affiliation in primates

Levels of aggression may be affected by stability of social relationships or by population density. A number of studies of nonhuman primates have indicated that spatial density influences agonistic activity levels less than does social density. Artificial fissioning of a captive troop of rhesus macaques was undertaken and the resultant differences in patterns of aggression and affiliation were examined. If population density has a major effect on levels of aggression, then fissioning will result in a decrease in aggression; if social stability has a major effect on levels of aggression, then fissioning is likely to be accompanied by an increase in aggression. An increase in rates of both aggressive and affiliative behavior resulted from artificial troop fissioning. These findings concur with other studies that have concluded that social stability is a more important determinant of primate aggression than is population density. Nonhuman primates use affiliative mechanisms to adjust their behavior when population density increases such that potentially adverse consequences of crowding are avoided.     

Shaping in the 21st century: Moving percentile schedules into applied settings

The present paper provides a primer on percentile reinforcement schedules, which have been used for two decades to study response differentiation and shaping in the laboratory. Arranged in applied settings, percentile procedures could be used to specify response criteria, standardizing treatment across subjects, trainers, and times to provide a more consistent training environment while maintaining the sensitivity to the individual's repertoire that is the hallmark of shaping. Percentile schedules are also valuable tools in analyzing the variables of which responding is a function, both inside and outside the laboratory. Finally, by formalizing the rules of shaping, percentile schedules provide a useful heuristic of the processes involved in shaping behavior, even for those situations that may not easily permit their implementation. As such, they may help further sensitize trainers and researchers alike to variables of critical importance in behavior change.     

Reward Density And Variable-interval Schedule Performance In An Open Economy

There is no general agreement regarding the form of the relation between response rate and reinforcement rate when single schedules of reinforcement are studied in an open economy. The present study assessed the form of this relation using reward density, which incorporates both reinforcement rate and duration of access to food, as an independent variable. Reward density was manipulated with 4 pigeons by changing the value of the variable-interval schedule, the hopper duration, or both. The relations between response rate and reward density were sharply rising and hyperbolic in 3 of 4 pigeons, replicating results obtained by Catania and Reynolds (1968). Because eating efficiency was lower in conditions that provided longer hopper durations, programmed reward densities differed from obtained reward densities. When response rates were examined as a function of obtained reward densities, the same relations were demonstrated more strongly. In further clarifying the relation between response rate and reward density in an open economy, these results lend support to the conclusion that open and closed economies yield different behavioral effects.     

Estimating an unobserved component of a serial response time model

A method is developed for estimating the response time distribution of an unobserved component in a two-component serial model, assuming the components are stochastically independent. The estimate of the component's density function is constrained only to be unimodal and non-negative. Numerical examples suggest that the method can yield reasonably accurate estimates with sample sizes of 300 and, in some cases, with sample sizes as small as 100.The author wishes to thank David Kohfeld, Jim Ramsay, Jim Townsend and two anonymous referees for a number of useful and stimulating comments on an earlier version of this paper.     

Within-session changes in the VI response function: separating food density from elapsed session time.

Previous studies examining the relationship between response rate and reinforcement rate on variable-interval schedules (the variable-interval response function) have confounded elapsed session time with within-session changes in food density. The present experiments attempted to manipulate these factors independently and thus isolate their effects on responding. In Experiment 1, 7 rats pressed a bar for food on a series of four variable-interval schedules (7.5 s, 15 s, 30 s, and 480 s). Elapsed session time was held constant while food density was manipulated via a presession feeding. Changes in food density altered the form of the variable-interval response function, independently of elapsed session time. In Experiment 2, 8 rats responded on the same series of variable-interval schedules as in Experiment 1, but food density was held constant and elapsed session time was manipulated via the use of timeout periods. The results revealed no evidence for an effect of elapsed session time independent of food density. The present results extend a recent analysis of the variable-interval response function by Dougan, Kuh, and Vink (1993) by identifying food density as an important factor determining the form of the function. The present results also help clarify the controversy over the correct empirical form of the variable-interval response function by further defining the variables responsible for differences in the form of that function.     

Maspin在腮腺癌中的表达及其与微血管密度的关系

为检测乳腺丝氨酸蛋白酶抑制剂（maspin）在腮腺癌中的表达,探讨其与腮腺癌I洛床病理特征及微血管密度（MVD）的关系。应用免疫组化技术分别对50例腮腺癌组织及30例瘤旁正常组织行maspin蛋白半定量测定,并对前者行CD34蛋白半定量测定,与各临床病理指标进行统计学分析。发现maspin、MVD在腮腺癌组织中表达与淋巴转移、术后复发、分化程度显著相关,后者的表达还与腮腺癌的临床分期密切相关。因此,maspin与MVD的联合检测,在判断恶性程度及顸后等方面具有重要的临床意义。     

The rise of information in an evolutionary universe

This paper outlines the grand scenario of cosmic evolution by examining the ongoing changes among radiation, matter and life in standard, big‐bang cosmology. Using aspects of non‐equilibrium thermodynamics and information science, we argue that it is the contrasting temporal behavior of various energy densities that have given rise to the environments needed for the emergence of galaxies, stars, planets, and life forms. We furthermore argue that a necessary (though perhaps not sufficient) condition—a veritable prime mover—for the emergence of such ordered structures of growing complexity is the expansion of the Universe itself. Neither demon‐strably new science nor appeals to non‐science are needed to explain the impressive hierarchy of developmental change, from quark to quasar, from microbe to mind.     

On the low-frequency vibrational spectrum of water

A new assignment is proposed for the low-frequency region of the vibrational spectrum of water, based on a comparison of the times of relevant occurring events. The time-matching is made between the dynamics of the rupture and formation time of the hydrogen bond, and the so-called bending and stretching oscillation periods of the O–H ··· O tetrahedral network. The same assignment also emerges by comparing thermal and solute concentration effects. Furthermore, a critical re-examination of the literature already existing on the subject corroborates the now proposed assignments for the modes at 60 and 170 cm^?1. These are considered to arise first from a transverse acoustic phonon with a low-frequency contribution sensitive to temperature and concentration effects, and second from external motions such as translations or restricted rotations of small water clusters inside a cage, and subjected to its potential field.     

Alcohol Availability and Violence among Inner-City Adolescents: A Multi-Level Analysis of the Role of Alcohol Outlet Density

Researchers recognize that the connection between alcohol and peer violence may relate to community level ecological factors, such as the location of businesses that sell alcohol. Building on previous research among adults, this study examines the relationship between alcohol outlet density and violent behaviors among adolescents, taking into account demographic characteristics, individual alcohol use, and neighborhood level socioeconomic indicators. Data drawn from a diverse Emergency Department based sample of 1,050 urban adolescents, combined with tract level data from the state liquor control commission and U.S. Census, were analyzed. Results of multivariate multi-level regression analysis indicate that alcohol outlet density is significantly related to adolescents’ violent behaviors, controlling for demographic characteristics and individual alcohol use. Census tract level socioeconomic indicators were not significantly associated with youth violence. Findings suggest that alcohol outlet density regulation should be considered as part of broader violence prevention strategies for urban adolescents.