This investigation examined the effects of randomizing components of an interdependent group contingency procedure on the target behavior of 12 students in a second-grade classroom in a rural southeastern school district. Specifically, using a multiphase time-series design (i.e., A-B-A-C-B-C design) levels of disruptive behavior were compared across baseline, an intervention phase with only randomized reinforcers (the RRϩ phase), and an intervention phase with all components randomized (R-ALL phase). Results suggest that both interventions were successful in decreasing levels of disruptive behavior, with the R-ALL phase resulting in lower mean, and more stable, percentages of disruptive behavior. The advantages to randomizing components within a group contingency procedure are discussed, because this procedure not only incorporates the strengths of an interdependent group contingency, but also addresses the limitations.

2‐Acetylpyridine hydrazone derivatives of benzothiazole, benzoxazole, and benzimidazole were found to exhibit potent cytotoxic activity against the growth of suspended leukemia and lymphomas. They were also active in a number of solid tumor screens, e.g. HeLa uterine carcinoma, SOS bone osteosarcoma, lung MB9812, lung A549, Mcf‐7 breast growth. In L1210 lymphoid leukemia cells the compounds preferentially inhibited RNA synthesis followed by DNA synthesis at 100 μM after 60 min. The reduction of de novo purine synthesis by the compounds at the regulatory sites PRPP‐amido transferase, IMP dehydrogenase and dihydrofolate reductase was responsible for the suppression of nucleic synthesis. Other minor sites where the agents have metabolic effects were thymidylate synthetase and thymidine kinase which would be additive with the overall inhibition of cell growth. The ct‐DNA studies suggest that the compounds also interacted with the DNA molecule itself, probably affecting template activity.

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We can understand viewed scenes and extract task-relevant information within a few hundred milliseconds. This process is generally supported by three cortical regions that show selectivity for scene images: parahippocampal place area (PPA), medial place area (MPA) and occipital place area (OPA). Prior studies have focused on the visual information each region is responsive to, usually within the context of recognition or navigation. Here, we move beyond these tasks to investigate gaze allocation during scene viewing. Eye movements rely on a scene’s visual representation to direct saccades, and thus foveal vision. In particular, we focus on the contribution of OPA, which is: (i) located in occipito-parietal cortex, likely feeding information into parts of the dorsal pathway critical for eye movements; and (ii) contains strong retinotopic representations of the contralateral visual field. Participants viewed scene images for 1034 ms while their eye movements were recorded. On half of the trials, a 500 ms train of five transcranial magnetic stimulation (TMS) pulses was applied to the participant’s cortex, starting at scene onset. TMS was applied to the right hemisphere over either OPA or the occipital face area (OFA), which also exhibits a contralateral visual field bias but shows selectivity for face stimuli. Participants generally made an overall left-to-right, top-to-bottom pattern of eye movements across all conditions. When TMS was applied to OPA, there was an increased saccade latency for eye movements toward the contralateral relative to the ipsilateral visual field after the final TMS pulse (400 ms). Additionally, TMS to the OPA biased fixation positions away from the contralateral side of the scene compared to the control condition, while the OFA group showed no such effect. There was no effect on horizontal saccade amplitudes. These combined results suggest that OPA might serve to represent local scene information that can then be utilized by visuomotor control networks to guide gaze allocation in natural scenes.