A SIMPLE ULTRA HIGH RESOLUTION SQUID RESISTANCE BRIDGE

On décrit un pont de résistance simple et bon marché, capable de détecter des changements faibles de résistance avec une résolution allant jusqu'à 1/107. Cette méthode représente une amélioration de deux ordres de grandeur par rapport à un circuit potentiométrique SQUID conventionnel. Elle égale la résolution obtenue par comparateurs de courants (une méthode coûteuse) et a l'avantage supplémentaire sur ces derniers de pouvoir être utilisée avec des échantillons de très faibles résistances.A simple and inexpensive resistance bridge is described which can monitor small changes in resistance with a resolution of up to 1 in 107. Its performance improves on that of the conventional SQUID potentiometric circuit by up to two orders of magnitude; its resolution equals that obtained with (expensive) current comparators, with the added advantage that, unlike the latter, it can be used with very small sample resistances

Changes in adipose tissue composition in malnourished patients before and after liver transplantation: A carbon-13 magnetic resonance spectroscopy and gas-liquid chromatography study

We investigated adipose tissue fatty acid composition in 22 moderately to severely malnourished patients with cirrhosis and in 22 healthy volunteers by in vivo carbon-13 magnetic resonance spectroscopy (MRS). Gas-liquid chromatography (GLC) of adipose tissue samples was also performed in 11 of the patients and in 4 volunteers. In vivo13C magnetic resonance spectra were obtained from the subcutaneous adipose tissue before and after eight weeks following orthotopic liver transplantation (OLT). Adipose tissue biopsy samples were obtained for GLC analysis at the time of transplantation in the patients and at inguinal hernia repair in the 4 volunteers. No significant differences were found in the subcutaneous adipose tissue total-saturated, - polyunsaturated or -monounsaturated fatty acid composition between patients and healthy volunteers by in vivo13C MRS. GLC analysis of adipose tissue samples confirmed that total levels of saturated, poly-, and monounsaturated fatty acids remained the same but revealed significant differences in levels of individual fatty acids, particularly n-3 fatty acids (total n-3, cirrhotics: .84% ± .07% vs. controls: 1.36% ± .13%, P < .01). Eight weeks following transplantation, recipients showed a considerable increase in body mass (pretransplantation: 59.3 ± 3.2 vs. posttransplantation: 63.2 ± 3 kg, P < .01). 13C MRS revealed a significant increase in saturated fatty acids (pretransplantation: 21.6 ± 2.8 vs. posttransplantation: 25.5% ± 1.2%, P < .05) and a significant decrease in unsaturated fatty acids. The application of noninvasive MRS techniques may be important to identify the differential uptake of fats, examining both specific fatty acids and different body fat compartments. In the future, this may be useful in optimizing the dietary management of severely malnourished patients with chronic liver disease before liver transplantation

An agency theoretic analysis of the professionalized family firm

The professionalized firm must evaluate the performance of managers and provide incentives that will motivate them to achieve the firm's goals. Using the agency theoretic framework we develop propositions on how differences in goals, altruistic tendencies, and strategic time horizons might affect performance evaluation and incentive compensation in family firms that employ both family and nonfamily managers and how these differences would affect the performance of the professionalized family firms relative to that of nonfamily firms