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.     

Decisions to donate bone marrow: The role of attitudes and subjective norms across cultures

Abstract

This paper reports the results of a field investigation of the determinants of decisions to donate bone marrow. Predictions are made on the basis of a modification of the theory of reasoned action wherein attitudes are operational-ized in separate affective and evaluative components. Boundary conditions of the theory of reasoned action are further explored by examining the effects of culture (Hong Kong Chinese, N= 190; American Chinese, N = 107; black Americans, N = 124; and white Americans N = 122) on decisions to donate for each of four targets: Immediate Family Members (TFM), Close Relatives (CR), Ethnic Strangers (ES), and Total Strangers (TS). For this life or death decision, the willingness to give is hypothesized to vary as a function of the so-called fitness value of the recipients (i.e., their capacity to contribute to the donor's inclusive fitness), as modified by cultural differences between group- versus independent-based cultures. Among other results, the following gradient was found in attitudes, subjective norms, and intentions for Chinese: IFM > CR > ES > TS; for Americans the pattern was IFM = CR > ES = TS. American Chinese showed stronger attitudes and felt norms, but not intentions, to give to close relatives than did Hong Kong Chinese, reflecting differential in-group/out-group pressures. Black and White Americans showed stronger attitudes, subjective norms, and intentions to donate to strangers than did Chinese.     

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.     

淋巴管生成与肿瘤转移间的关系

肿瘤淋巴管生成是肿瘤转移过程的必要环节,肿瘤细胞可以通过表达淋巴管生成的调控因子VEGF-C和VEGF-D诱导淋巴管生成,并且促进肿瘤细胞的淋巴道转移。肿瘤淋巴管生成及其对抗研究是当前肿瘤研究的热点,并有可能成为治疗肿瘤淋巴道转移的靶点。两者之间关系密切,并且相互作用,相互影响。     

Some effects of noncontingent positive reinforcement on multiply controlled problem behavior and compliance in a demand context

Functional analysis suggested that the problem behavior of an 8-year-old girl with autism was maintained by escape from demands and access to edible items. Noncontingent delivery of an edible item was sufficient to increase compliance and reduce the rate of problem behavior without the use of escape extinction in a demand context. Leaner and richer schedules of noncontingent reinforcement were equally effective, and there were minimal differences between noncontingent reinforcement and differential reinforcement of compliance.     

Asymptotic Densities in Logic and Type Theory

This paper presents a systematic approach for obtaining results from the area of quantitative investigations in logic and type theory. We investigate the proportion between tautologies (inhabited types) of a given length n against the number of all formulas (types) of length n. We investigate an asymptotic behavior of this fraction. Furthermore, we characterize the relation between number of premises of implicational formula (type) and the asymptotic probability of finding such formula among the all ones. We also deal with a distribution of these asymptotic probabilities. Using the same approach we also prove that the probability that randomly chosen fourth order type (or type of the order not greater than 4), which admits decidable lambda definability problem, is zero. Presented by Jacek Malinowski