Effects of growth with ethanol on fermentation and membrane fluidity of Saccharomyces cerevisiae

Saccharomyces cerevisiae HSc was grown with ethanol at concentrations up to 10% (v/v). The immediate effects of additions of externally added ethanol on CO₂ production and O₂ consumption of washed organisms were studied by stopped-flow membrane inlet quadrupole mass spectrometry. Fermentative activities of organisms grown with ethanol (0–5% v/v) showed similar sensitivities to inhibition by ethanol, whereas those grown with 10% (v/v) ethanol had become protected and were markedly less sensitive. The fluidity of subcellular membrane fractions was measured by determination of the temperature dependence of the rotational order parameter of the spin label 5-doxyl stearic acid (free radical) by electron spin resonance. Mitochondria prepared from yeasts grown with 0, 7 and 9% (v/v) ethanol showed similar overall fluidity, although differences in temperature-dependent behaviour indicate altered lipid composition or lateral phase separations. On the other hand the microsomal fraction from organisms grown with 9% ethanol showed a remarkable increase in fluidity. These data suggest that the protective effects of growth with ethanol near the limit of tolerance on fermentative activities may arise from altered plasma membrane fluidity properties.     

Improvement in the accuracy of determining shear moduli for orthotropic bars with twisting

A method is described for improving the accuracy of measuring shear moduli under twisting conditions taking account of the compliance of elements by testing an additional specimen.Translated from Problemy Prochnosti, No. 3, pp. 60–62, March, 1994.     

Tuberculosis presenting with generalized lymphadenopathy, pulmonary infiltrates, and bone destruction in a young man

Although tuberculosis is still relatively common in Canada, particularly among recent immigrants, one tends not to consider it very strongly in the absence of definite pulmonary symptoms and in the face of negative smears of expectorated sputum and bronchial washings. We present the case of a young immigrant from Ethiopia who presented with mild constitutional symptoms, bony tenderness of the chest wall, generalized lymphadenopathy, and rib erosions--a set of features which, in the face of smear-negative sputum and bronchial washings, raised a possibility of lymphoma. Eventually, diagnosis of tuberculous lymphadenitis and osteomyelitis was established and the patient responded well to appropriate therapy.     

Surface tension nonuniformity effect on fluid distribution in a porous body

Surface forces nonuniformity within the volume of a capillary system for a given structure has been examined in terms of its effect on a wetting fluid distribution. This approach enables the distribution for a porous body with a uniform structure to be quantified using a specific function for the pore volume size distribution. The surface forces nonuniformity effect is illustrated using a fibrous structure impregnated with molten copper.Institute of Materials Science Problems, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya, No. 8(368), pp. 66–69, August, 1993.     

"Memory independence and memory interference in cognitive development": Correction.

Reports an error in the original article by C. J. Brainerd and V. F. Reyna (Psychological Review, 1993[Jan], Vol 100[1], 42–67). On page 56, there were some incorrect data values in the 3rd and 4th columns of Table 4. The amended table is presented. (The following abstract of this article originally appeared in record 1993-17013-001.) Recent experiments have established the surprising fact that age improvements in reasoning are often dissociated from improvements in memory for determinative informational inputs. Fuzzy-trace theory explains this memory-independence effect on the grounds that reasoning operations do not directly access verbatim traces of critical background information but, rather, process gist that was retrieved and edited in parallel with the encoding of such information. This explanation also envisions 2 ways in which children's memory and reasoning might be mutually interfering: (1) memory-to-reasoning interference, a tendency to process verbatim traces of background inputs on both memory probes and reasoning problems that simultaneously improves memory performance and impairs reasoning and (2) reasoning-to-memory interference… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Potential fields based on circular multipole series

In the frame of cylindrical coordinates the Dirichlet outer boundary-value problem is solved on the basis of circular multipoles. A number of multipole-cylindrical fields is calculated.     

In situ13C NMR study of tert-butanol interaction with moderately concentrated sulfuric acid

An in situ NMR study of tert-butanol dehydration in 95 and 85% sulfuric acid did not indicate the formation of tert-butyl cations as active reaction intermediates. Instead, only NMR lines from oxonium ions under the condition of fast exchange with water and the acid were observed. It is most likely that, in the concentrated acid, the active intermediates of this reaction are represented by tert-butyl sulfuric ester which probably is a precursor of invisible tert-butyl carbenium ions representing short-lived excited or transition states.