Modification of the Ehrlich ascites tumor cell nuclear lipids

The fatty acid composition of Ehrilich ascites tumor cell nuclei was differend when the tumor-bearing mice were fed diets rich in either coconut or sunflower oil. When coconut oil was fed, the monoenoic fatty acid content of many of the nuclear lipids was increased and their polyenoic fatty acid content was reduced as compared with the sunflower oil diet. By contrast, only small changes were produced in the saturated fatty acid contents of the nuclear lipids. The nuclear membrane choline phospholipid, ethanolamine phospholipid and combined serine phospholipid plus inositol phospholipid fractions exhibited statistically significant changes in fatty acid composition, but the sphingomyelins were not altered appreciably by dietary lipid modification. The fatty acid composition of the small quantity of phospholipids associated with the chromatin was much more resistant to diet-induced mosification. Except for sphingomyelin, the fatty acid composition of the chromatin phospholipids was different from that of the corresponding nuclear membrane phospholipids, containing much larger amounts of fatty acids having less than 16 carbon atoms. The fatty acid compositons of the nuclear triaclglycerols and cholesterol esters, which were associated almost entirely with the chromatin, were modified by the dietary lipid modifications. There were no changes in the DNA, RNA or lipid content of these nuclei. Therefore, this experimental system can be used to prepare mamalian nuclei that differ appreciably only in their fatty acyl composition.     

Effects of Vegetation Cover on the Microwave Radiometric Sensitivity to Soil Moisture

The reduction in sensitivity of the microwave brightness temperature to soil moisture content due to vegetation cover is analyzed using airborne observations made at 1.4 and 5 GHz. The data were acquired during six flights in 1978 over a test site near Colby, Kansas. The test site consisted of bare soil, wheat stubble, and fully mature corn fields. The results for corn indicate that the radiometric sensitivity to soil moisture S decreases in magnitude with increasing frequency and with increasing angle of incidence (relative to nadir).The sensitivity reduction factor, defined in terms of the radiometric sensitivities for bare soil and canopy-covered conditions Y=1 - Scan/ Ss was found to be equal to 0.65 for normal incidence at 1.4 GHz, and increases to 0.89 at 5 GHz. These results confirm previous conclusions that the presence of vegetation cover may pose a serious problem for soil moisture detection with passive microwave sensors.     

Functional status and well-being in a placebo-controlled trial of zidovudine in early symptomatic HIV infection

To determine the effect of zidovudine on functional status and well-being in patients with early symptomatic human immunodeficiency virus (HIV) infection, 70 subjects in a randomized, placebo-controlled trial (ACTG Protocol 016) were observed for 1 year using a brief quality-of-life questionnaire. Thirty-four subjects were assigned to placebo and 36 subjects to zidovudine, 200 mg orally every 4 h (1,200 mg daily). Functional status and well-being were measured every 3 months using a 30-item self-administered questionnaire derived from health ratings from the Medical Outcomes Study. The mean changes from baseline for zidovudine versus placebo groups were compared using paired and two-sample t tests. Subjects receiving a placebo reported better quality of life compared to baseline than subjects receiving zidovudine at 24 weeks for all dimensions of well-being, including overall health, energy, mental health, health distress, pain, and quality of life. The difference between the two groups' changes from baseline for overall health was 11.5 points on a 100-point scale (p = 0.02), and 11.1 points for energy (0.002). There were no differences between changes from baseline along various dimensions of functional status (physical, social, role, and cognitive function). At 52 weeks both groups reported worse overall health than at baseline, and changes in scores were more similar for the two groups. Although zidovudine has previously been demonstrated to delay progression of disease for patients with mildly symptomatic HIV infection, early in treatment the net effect of a 1,200 mg daily dose of zidovudine may diminish patients' subjective well-being.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chorda tympani transection and selective desalivation differentially disrupt two-lever salt discrimination performance in rats

Water-restricted rats were trained to press 1 of 2 levers if a sampled stimulus was NaCl and the other lever if the stimulus was KCl (0.05, 0.1, or 0.2 M). Responses were reinforced with water. After training, the average rate of correct responses was 90%. Performance was unchanged following sham surgery. Chorda tympani (CT) transection reduced average discrimination performance to 67.7% correct, and extirpation of the sublingual and submaxillary salivary glands reduced average performance to 80% correct. Although selective desalivation moderately reduced discriminability, a disrupted salivary environment does not explain the effects of CT transection. More likely, the discrimination deficit in CT-transected rats reflects a loss of critical taste input conveyed by the CT about salts.     

Matrix collagen type and pore size influence behaviour of seeded canine chondrocytes

This study directly compared the behaviour of chondrocytes in porous matrices comprising different collagen types and different pore diameters. There was a dramatic difference in the morphology of the cells in the type I and type II collagen matrices. The cells in the type II collagen matrix retained their chondrocytic morphology and synthesized glycosaminoglycans, while in the type I matrix the chondrocytes displayed a fibroblastic morphology with less biosynthetic activity than those in the type II. Small pore diameter affected morphology initially in the type I matrices and showed a higher increase of DNA content, but with time the cells lost the chondrocytic morphology. Our results demonstrate the marked influence of collagen type and pore characteristics on the phenotypic expression of seeded chondrocytes.     

Inferring category attributes from exemplar attributes: Geometric shapes and social categories.

Three experiments tested the hypothesis that judgments about the attributes of categories are disproportionately based on the characteristics of exemplars that fit the category. In the first 2 experiments, subjects were presented with good and bad exemplars of categories with defining attributes (rectangles, triangles, pentagons, and ellipses) in which different colors were arbitrarily paired with the good and poor exemplars. In both experiments, subjects erroneously judged the colors paired with the good exemplars as more frequent than colors paired with the poor exemplars. A third experiment, using social categories, examined whether attributes associated with a single category member were more likely to generalize to the category as a whole for prototypical than for nonprototypical category members. Subjects were presented with information about individual fraternity members who varied in prototypicality, and the tendency to infer a target behavior (liberal vs. conservative voting behavior) from the individual fraternity member to the fraternity as a whole increased with the prototypicality of the category member. Implications for the contact hypothesis, category–exemplar relations, and belief stability are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

A NOMENCLATOR USED BY PROPAGANDA FIDE DURING THE CHINESE RITES CONTROVERSY

The irresolvable conflicts between the missionaries of the Propaganda Fide and the Jesuits, generated by the Chinese Rites Controversy during the early 18th century, are considered most responsible for the failure of Christianity in this great country. A refined nomenclator concealed secret documents exchanged between Rome and Peking.     

Effects of perceived ability and grade status on social interaction and influence in cooperative groups.

In this study we investigated how a natural status characteristic (grade level) and an experimentally induced status characteristic (ability) combine to affect group interaction and interpersonal perception in homogeneous and heterogeneous groups. Eighty male fifth and sixth graders were randomly assigned to groups of four that were made into homogeneous or heterogeneous "ability" groups on the basis of a bogus aptitude test. Their social interaction was videotaped as groups worked on a group consensus task. The data indicated that the two status characteristics (actual and induced) had a similar and significant effect on the social interaction in the groups. High-status students dominated group interaction, were more influential, and were more likely to be perceived as leaders. The data also indicated that differences in helping behavior may be due, in part, to the perceived status of the student and not only to the student's ability to give help. (PsycINFO Database Record (c) 2010 APA, all rights reserved)