The relation of multiple-schedule behavioral contrast to deprivation,time in session,and within-session changes in responding

Pigeons' keypecking was reinforced by food on baseline schedules of multiple variable interval (VI) x VI x and on contrast schedules of multiple VI x VI y. Deprivation of food was varied by maintaining subjects at 75%, 85%, and 95% (+/- 2%) of their free-feeding weights. Positive and negative behavioral contrast were observed. The size of the contrast was not systematically altered by changes in deprivation. Positive and negative contrast were both larger later in the session than they were earlier. Within-session decreases in responding were steeper for the baseline than for the contrast schedules for positive contrast. Within-session decreases were steeper for the contrast than for the baseline schedules for negative contrast. These results were predicted by the idea that different amounts of habituation to the reinforcer during the baseline and contrast schedules contribute to behavioral contrast. The results show that contrast occurs under conditions that reduce the effect of the following component. The results support the assumption that positive and negative contrast are produced by symmetrical theoretical variables.     

Subject-matter oriented measurement of achievement motivation

European Journal of Psychology of Education -     

Effects of identical context on visual pattern recognition by pigeons

The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth—an upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair 2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results.     

Blurring the color line: The desegregation of the Baltimore city public schools, 1954–1994

Perched on the Mason-Dixon line, Baltimore ignored calls for resistance from its southern neighbors by becoming one of the first cities in the country to comply withBrown. By the beginning of the 1955 school year, leaders had implemented a desegregation plan, and Baltimore was being applauded for the early and peaceful integration of its public schools. Within a few years, however, the praise faded as it became clear that Baltimore still suffered from de facto segregation. Faced with this reality, the school board refused to take the steps necessary to remedy the problem, instead shifting the blame to society at large. This failure by the board started a pattern of abandonment by school leadership that culminated in 1991 with the privatization of several of Baltimore's public schools. The result of this abandonment is a crippled school system that still has not dealt with issues of race and equality.     

Video-assisted thoracoscopic surgery （VATS） for bilateral primary spontaneous pneumothorax

Objective:To review our experience of the treatment of bilateral primary spontaneous pneumothorax (PSP) by video-assisted thoracoscopic surgery (VATS). Materials and methods: Retrospective chart review was followed by an on-clinic or telephone interview. Patients were cared for by one thoracic surgeon in four medical centers or community hospitals in Northern and Central Taiwan. Thirteen patients with bilateral PSP underwent bilateral VATS simultaneously or sequentially from July 1994 to December 2005. Results: Twelve males and one female, with age ranging from 15 to 36 years (mean 23.1 years), were treated with VATS for bilateral PSP, under the indications of bilateral pneumothoracis simultaneously (n=4) or sequentially (n=9). The interval between the first and second contra-lateral VATS procedure for non-simultaneous PSP patients ranged from 7 d to 6 years. Eleven of 13 patients (84.6%) had prominent pulmonary bullae/blebs, and underwent bullae resection with mechanical or chemical pleurodesis. The mean operative time was (45.6±18.3) min (range 25-96 min) and (120.6±28.7) min (range 84-166 min) respectively for the non-simultaneous (second VATS for the recurrence of contralateral side after first VATS) and simultaneous (bilateral VATS in one operation) procedures. There was no postoperative mortality. However, prolonged air leakage (>7 d) occurred in one patient (7.7%) who recovered after conservative treatment. The mean duration of chest tube drainage was 3.1 d and the median follow up period was 3.4 years. Conclusions: VATS is a safe and effective procedure in the treatment of bilateral PSP. Bilateral VATS is only recommended for patients with simultaneously bilateral PSP, because the incidence of recurrence, even with visible bullae, was not so high in my group and in some previous literature. Bilateral VATS in a supine position should only be used in selective cases, because of possible pleural adhesion or hidden bullae on the posterior side.     

Context-sensitive regularities in English vowel spelling

The predictive value of rime spellings in English was compared directly to other types of regularities beyond the level of the single letter. A computer-assisted analysis of a list of twenty-four thousand written words, each paired with its corresponding pronunciation, reveals that only a small number of rime spellings are highly regular in their pronunciations. The conventional division of vowel letter pronunciations into short and long in closed and open written syllables is the most reliable key to English pronunciation. Our findings support the notion that English spelling is based at least in part on syllable structure. In addition, prefixes and suffixes provide very reliable clues to pronunciation, which suggests that their regularity should be exploited in the teaching of reading.     

Appropriability of innovation benefit as a predictor of the source of innovation

It has been empirically observed that, in some industries product users are the most frequent sources of product innovations while, in other industries, product manufacturers are. I hypothesize that such differences are caused by differences in the ability of these two “functional” categories of innovators to appropriate innovation benefit. I explore this hypothesis by examining the real-world effectiveness of mechanisms (such as patents and lead time) used for the appropriation of innovation benefit and the dependence of this effectiveness on the functional relationship between innovator and innovation.     

Relative efficiency of R&D activities: A cross-country study accounting for environmental factors in the DEA approach

This paper applies the production framework associated with the data envelopment analysis (DEA) method to evaluate the relative efficiency of R&D activities across countries. R&D capital stocks and manpower are treated as inputs while patents and academic publications are considered as outputs. A three-stage approach, which involves using DEA for evaluating efficiency and using Tobit regressions for controlling the external environment, is applied to 30 countries in recent years. The results show that less than one-half of the countries are fully efficient in R&D activities and that more than two-thirds are at the stage of increasing returns to scale. Most countries have a more significant advantage in producing SCI cum EI publications than in generating patents.     

Marital conflict and conduct problems in Children of Twins

The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14-39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate that genetic and nonshared environmental factors influence the risk of marital conflict. Furthermore, genetic influences mediated the association between marital conflict frequency and conduct problems. These results highlight the need for quasiexperimental designs in investigations of intergenerational associations.