Signalled free-operant avoidance of shock by pigeons pecking a key

Two pigeons were trained to peck a key under a free-operant avoidance schedule. Then, changes in key color signalled the beginning (safe period) and the end (warning period) of the response-shock interval, with a response required to change the key color. Finally, a change in key color signalled the warning period and either a response or a shock reinstated the safe stimulus. During signalled avoidance, response rate was higher during the warning stimulus than during the safe stimulus. More responding tended to occur in the warning stimulus when it was terminated by either a response or a shock than by only a response. In either procedure, response latency during the warning stimulus was a function of the duration of the warning stimulus. In general, response and shock rate were higher during unsignalled than during signalled avoidance. When the warning stimulus was brief, the results were similar to those of unsignalled avoidance. These results confirm previous findings with pigeons, are in general agreement with data provided by other species in studies of signalled avoidance, and thereby indicate the transituationality of the key-pecking operant.     

The role of anionic, imidic and amidic forms in structure-activity relationships. Conjugation and bacteriostatic activity in sulphonamides.

The electronic structures of anionic, imidic and amidic forms of sulphonamides were investigated and compared by means of I.R., Raman and U.V. spectroscopy. Indices reflecting the electronic situation of the common moiety p-H2N-C6H4-SO2 was a whole, although not necessarily related, physically, to any event taking place in the biological processes, were found to correlate with the in vitro bacteriostatic activity of the specific individual forms. The influence of N1-substituents both on the SO2 electronic features and on the coupling between the para amino group and the phenyl ring was discussed. It resulted that the most active chemical species, in this class of compounds, are characterized, electronically, by the most electron-rich common moiety and, in particular, by the most negative oxygens in the SO2 group and the most available (less engaged) lone-pair in the rho-amino group. These conclusions give a new settlement both to the problem of resonance and to the relation between resonance effects and bacteriostatic activity in this class of compounds.     

老化的年龄标识:主观年龄对老年人主观老化体验的影响

为证明年龄对老化的标识作用,研究假设降低被试的主观年龄可减少老年人的主观老化体验。采取实验组控制组前测后测设计,以主观年龄为自变量,分为"等于年代年龄"(控制组)和"小于年代年龄10±5岁"(实验组)两种水平,随机分配至两组的62名老年被试填写《个人老化体验问卷》,评估其主观老化体验。结果显示,实验组在后测中的主观老化体验不仅显著低于本组前测,也显著低于控制组,且这一结果不受被试最初自评的主观年龄影响。原假设得到证明,支持年龄对老化的标识作用。年龄标识对老化意义的简单化建构了世俗的绝对老化观。     

Primary School Correlates of Secondary School Achievement

This study is an investigation of the relationship between third grade final marks, achievement test scores, and subsequent achievement in elementary and secondary school. It was focused on the early identification of students for whom changes in the curriculum might be indicated.     

Strategic Revenue Management under Uncertainty: A Case Study on Real Estate Projects in India

This paper proposes an approach for strategic revenue management under uncertainty for real estate projects. It integrates three modelling techniques: first, artificial neural network integrated support vector machines for forecasting the profit and loss‐making real estate residential projects; second, analytical network process approach using decision making trials and evaluation laboratory methodology for establishing interrelationships among factors; and third, multiobjective genetic algorithm approach for obtaining optimal numbers and types of apartments in a real estate project. We compare the respective revenues generated with the new number of apartments and price from the suggested revenue maximization model and that of the old practiced one through a case study of India. Copyright © 2015 John Wiley & Sons, Ltd.