The effect of environmental temperature on sebum composition in tropical and temperate breeds of cattle

This study compared the effect of environmental temperature on sebum composition in 2 breeds of cattle, British (SH) and Brahman (GB), which differ in their abilities to tolerate heat. By long-term exposure of both breeds to environmental temperatures of 24 C and 32 C and the more heat-tolerant GB breed to 38 C, it was possible to make breed comparison at (a) different body temperatures, i.e, when all animals were exposed to the same environmental temperature, and (b), at the same body temperature, i.e., when the 2 breeds were exposed to different ambient temperatures. The composition of sebum excreted to saturation level on the skin surface was determined. At the same body temperatures, the amounts of fatty acids in each lipid class were higher in GB than in SH animals except during hyperthermia when the amounts of triglyceride fatty acids were similar in both breeds. The total amounts of individual fatty acids except 14∶1, 16∶1, 20∶0 and 14∶OH were higher in both breeds at 32 C than at 24 C. The GB cattle excreted more essential fatty acids (EFA) than the SH cattle at 24 C and at 32 C. There was a significant genotype by environment interaction in the amounts of EFA partitioned between triglycerides and wax esters; in GB cattle, the amount of EFA excreted in triglycerides decreased whereas the amount excreted in wax esters increased with rising body temperature.     

Enhanced HBsAb production in pathogenesis of fulminant viral hepatitis type B

The possible importance of humoral immunity in the pathogenesis of fulminant hepatitis was investigated by comparing 17 patients with fulminant hepatitis type B with 20 patients with severe but non-fulminant disease. Hepatitis B surface antigen (HBsAg) was cleared from the serum significantly faster (P less than 0-001) in those with fulminant hepatitis, and in 41% anti-HBsAg (HBsAb) was detectable by radioimmunoassay (RIA) at presentation. In all 11 sera from patients with fulminant hepatitis that were examined by electron microscopy aggregates of HBsAg and HBsAb were seen. In contrast, HBsAb was never detected by RIA in those with non-fulminant hepatitis, and in only one serum specimen (5%) were aggregates seen on electron microscopy. A significant sex difference between fulminant and non-fulminant hepatitis was observed, 65% of patients with fulminant hepatitis but only 15% of patients with non-fulminant hepatitis being women (P less than 0-01). An enhanced production of HBsAb in fulminant hepatitis, by leading to free HBsAb in portal blood, may cause an Arthus reaction in the sinusoids of the liver with ensuing ischaemic necrosis of hepatocytes.     

Safety and reliability in superconducting fusion magnet systems

Superconducting toroidal field coils for future commercial Tokamak reactors must operate safely and reliably for periods of up to 30 years or more with minimal interruption for maintenance. This paper represents an initial attempt to consider safety and reliability issues for superconducting fusion magnets. Goals and approaches for safety and reliability are characterized. Possible accident initiators are identified, and the effect of mechanical, thermal, and electrical factors are examined, by using some early Tokamak reactor concepts as illustrations. Principal factors in magnet instrumentation and control are identified, and the role of engineered-safety features are discussed.     

Molecular weights from fractionation data by a simplified log-normal treatment

A simplified procedure is presented to estimate the two adjustable parameters in a lognormal distribution function. From values of these parameters, the weight distribution function, W(M), as well as various molecular weight averages can be calculated. The method was applied to fractionation data selected at random for several polymers. The agreement between calculated and reported values appears to be good.     

The generalization of assertions throughout a cognitive network.

30 undergraduates gave answers to sentence pairs of the following form: "Martians hate robins. Do Martians hate birds?" Objects of the sentence pairs were related as 1st- and 2nd-level superordinate and subordinate, and similar and dissimilar coordinate. Generalization between levels was consistent with a model based on judgment of set-subset relations among the object sets to which concepts refer. Coordinate generalization was described by a 2nd model based on judgments of the proportion of properties shared by 2 concepts. Implications of these findings for research on the syllogism are discussed. (French summary) (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Molecular weight changes during polyolefin autoxidation

Expressions were derived relating changes of intrinsic viscosity to reaction time, based on a scheme previously presented for the uncatalyzed, uninhibited thermal oxidation of polyolefins. A value of the kinetic parameter A may be obtained from these expressions by using an iterative type of procedure and employing data presented by other workers for the oxidation of atactic polybutene-1. This value of A was compared with the corresponding value obtained by the authors from rate of carbonyl formation studies in oxidation of atactic polybutene-1 by means of infrared absorption spectroscopy methods. The good agreement between the values of A obtained from the two different experimental techniques employed lends further support to the validity of the scheme used and the expressions derived therefrom.     

Intercostal thorascopic harvesting of the internal mammary artery for supercharging a pedicled rectus abdominis flap

This review on non-heartbeating donation focusses on three issues: the number of kidneys procured from a non-heartbeating donor programme, the transplant results and the influence of a non-heartbeating programme on public opinion regarding transplantation.