An educational format for teaching stress management to groups with a wide range of stress symptoms

In view of the pervasiveness of stress reactions in contemporary society, together with the limited availability of effective coping techniques, the authors attempted to develop a stress management program that combined education on the nature of stress disorders with instruction on several practical procedures useful in coping with stress. Our study used a general population drawn from a small rural university community. There were 38 subjects, 17 male and 21 female, in the final statistical analyses. One independent variable was a lecture-discussion format to present cognitive and relaxation skills. A second independent variable was biofeedback training to decrease frontal EMG activity. The subjects were divided into five treatment groups that consisted of one or some combination of these two treatment conditions. Dependent variables were the two scales—A-State and A-Trait—of Spielberger's STAI(Spielberger, Gorsuch, & Lushene, 1970) and an adaptive application of Kerle and Bialek's(1958) Subjective Stress Scale(SSS). The SSS served as an instrument to keep subjects aware of their physical and psychological responses to stress as well as providing a pre/post measure of reactions to stress as they experienced it. Results indicated that the lecture-discussion format was effective in reducing the subjects' level of stress as measured by the State-Trait Anxiety Inventory and the Subjective Stress Scale. There was no evidence that frontal EMG feedback relaxation training contributed to the reduction of stress.     

DAPI as a Useful Stain for Nuclear Quantitation

A simple-to-use fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI), visualizes nuclear DNA in both living and fixed cells. DAPI staining was used to determine the number of nuclei and to assess gross cell morphology. Following light microscopic analyses, the stained cells were processed for electron microscopy. Cells stained with DAPI showed no ultrastructural changes compared to the appearance of cells not stained with DAPI. DAPI staining allows multiple use of cells eliminating the need for duplicate samples.     

Nucleotide sequence of the thioredoxin gene fromEscherichia coli

The nucleotide sequence of the thioredoxin gene fromEscherichia coli was determined. The structural gene was identified on a cloned 3-kbPvuII Iragment by hybridization with a synthetic oligodeoxyribonucleotide corresponding to a part of the amino acid sequence of thioredoxin. Restriction-enzyme fragments were used as templates in the dideoxy sequence method, directly and after subcloning into M13mp8. A segment of 450 nucleotides was determined using both strands7 alternatively, without extensive overlaps. The sequence contains the thioredoxin coding region, a potential ribosome-binding site, and a putative promotor region. The predicted amino acid sequence differs by two inversions from the previously given thioredoxin sequence. The revised sequence is presented and the results further show that thioredoxins fromE. coli B and K12 are identical.     

Isolation and initial characterization of myelin-like membrane fractions from the nerve cord of earthworms (Lumbricus terrestris L)

We report here the isolation of fractions enriched in components of the myelin-like membranes surrounding the giant axons of the earthworm.Lumbricus terrestris L. The composition and purity of the fractions have been assessed using SDS-protein electrophoresis, Western immunoblots, and electron microscopy. Preliminary enzyme assays indicated that the mitochondrial marker, succinate dehydrogenase, has a similar specific activity distribution in earthworm nerve cord and in mouse liver sedimentation velocity fractions, however, the distribution of the total units of activity among the fractions seems to indicate the existence of smaller mitochondria in earthworm nerve cord compared with mouse liver mitochondria. In earthworm nerve cord fractions, Na⁺/K⁺ ATPase and Ca²⁺/Mg²⁺ ATPase were found to be enriched exclusively in the fraction containing large plasma and myelin-like membranes, while in the mouse liver fractions, the total units of these two enzymes were found to be distributed broadly among fractions. 5-Nucleotidase activity in the earthworm nerve cord seemed to be restricted to the microsomal fractions (endomembrane network), with a very low activity associated with the large plasma and myelin-like membrane fraction. We have established the presence of keratins or prekeratins in the myelin-like membranes, probably in the form of tonofilaments. However, we could not show that the desmosome-like structures, characteristic of these membranes, are composed of those proteins described for vertebrate epithelial desmosomes.     

Genetic structuring in a Neotropical palm analyzed through an Andean orogenesis‐scenario

Andean orogenesis has driven the development of very high plant diversity in the Neotropics through its impact on landscape evolution and climate. The analysis of the intraspecific patterns of genetic structure in plants would permit inferring the effects of Andean uplift on the evolution and diversification of Neotropical flora. In this study, using microsatellite markers and Bayesian clustering analyses, we report the presence of four genetic clusters for the palm Oenocarpus bataua var. bataua which are located within four biogeographic regions in northwestern South America: (a) Chocó rain forest, (b) Amotape‐Huancabamba Zone, (c) northwestern Amazonian rain forest, and (d) southwestern Amazonian rain forest. We hypothesize that these clusters developed following three genetic diversification events mainly promoted by Andean orogenic events. Additionally, the distinct current climate dynamics among northwestern and southwestern Amazonia may maintain the genetic diversification detected in the western Amazon basin. Genetic exchange was identified between the clusters, including across the Andes region, discarding the possibility of any cluster to diversify as a distinct intraspecific variety. We identified a hot spot of genetic diversity in the northern Peruvian Amazon around the locality of Iquitos. We also detected a decrease in diversity with distance from this area in westward and southward direction within the Amazon basin and the eastern Andean foothills. Additionally, we confirmed the existence and divergence of O. bataua var. bataua from var. oligocarpus in northern South America, possibly expanding the distributional range of the latter variety beyond eastern Venezuela, to the central and eastern Andean cordilleras of Colombia. Based on our results, we suggest that Andean orogenesis is the main driver of genetic structuring and diversification in O. bataua within northwestern South America.