A new fixation procedure for preserving the ultrastructure of marine invertebrate tissues

Addition of 0·05% OsO₄ to a conventional glutaraldehyde fixative for the first 10 min of fixation was found to improve greatly the preservation of ultrastructure in the eggs of Urechis caupo. Several workers have since confirmed this result in other marine invertebrate tissues. Specific protocols and techniques are given. We believe that the OsO₄ rapidly renders the plasma membranes of cells freely permeable to glutaraldehyde, allowing faster penetration of this fixative. This method should be applicable to a wide variety of tissues that are difficult to fix.     

Short-circuiting of threat by experimentally altering cognitive appraisal.

Previous research has shown that film-induced threat could be reduced by appropriately designed narratives or sound tracks based on ego-defense theory. This study demonstrated that such a narrative, based on the concepts of denial and reaction formation, is even more effective if presented as an introductory statement before the film begins. It significantly reduced both physiological and self-report evidence of stress reaction. Moreover, the amount of stress reaction and the capacity of the narrative to reduce stress reaction depended upon personality. Ss high in disposition to deny threat as measured by various MMPI scales did indeed deny affective disturbance more than low deniers, while showing greater autonomic evidence of stress reaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)