Atmospheric emission and attenuation in the range 100 to 600 GHz measures from a mountain site

Further measurements of atmospheric emission from a site in the Canary Islands (Izana, âltitude 2.4 km) have been made during the month of August 1980. The measurements were made with a polarising Interferometer and a composite Ge bolometer. An independent measurement of the precipitable water vapour was made using Infrared Hygrometers. The experimental details are described and the spectra obtained are compared with model spectra using the measured precipitable water vapour.     

Realization of Finite Impulse Response Filters Using Coefficients +1, 0, and -1

New classes of nonrecursive linear digital filters are proposed as alternatives to conventional methods for digital signal processing devices. In fact, the traditional approach, where signal samples are represented by 8-15 bit words, can be very expensive to implement due to the complexity of multibit multipliers and adders. Filter structures consisting of a transversal filter with tap coefficients restricted to - 1, 0, or + 1 and cascaded with simple recursive sections are proposed. Using a mean square error criterion, dynamic programming methods to select optimum sets of coefficient values for the taps are presented and evaluated. It is shown that these structures lend themselves to very simple hardware implementations and offer a valid alternative to the conventional filtering approach. Designs for several example filters are presented, and their implementation complexity is examined.     

The effect of respiratory immunization on cell-mediated immune effector cells of the lung

In order to understand the mechanisms of cellular immune injury in hypersensitivity pneumonitis, the effect of type of antigen on cell-mediated immunity in guinea-pigs receiving respiratory immunization was studied. Lymphocytes obtained by pulmonary lavage were compared with those from peritoneal exudate following immunization with either a soluble protein, human serum albumin, or a particulate suspension of Thermoactinomyces vulgaris. Assays were obtained without mixing cells from these two sources. Statistically significant increases (13-22%) in the number of alveolar rosette-forming cells (RFC) were found in the animals immunized with either antigen, but only the particulate T. vulgaris was also capable of inducing a systemic increase of such cells. That this increase in RFC could be due to specifically reactive lymphocytes was demonstrated by the production of antigen-stimulated macrophage migration inhibition. Some evidence was obtained that indicated that T. vulgaris could act both as a non-specific B-cell stimulant and a specific T-cell activator. The concept of a hypothetical pulmonary 'barrier' is discussed which must be overcome to induce systemic immune responses following respiratory immunization. T. vulgaris must be added to the list of known agents or means for overcoming this 'barrier'.     

Suxamethonium-induced porcine malignant hyperthermia

Metabolic, haemodynamic and neuroendocrine responses to suxamethonium (SCh) were measured in five normal swine and five swine susceptible to malignant hyperthermia (MH), to compare the responses with those previously reported for halothane. Following SCh, the onset of MH was sooner and more abrupt than following halothane. The maximal changes in aerobic metabolism and body temperature sere similar, while the changes in lactate, potassium, hydrogen ion and catecholamine concentrations were smaller than those observed following halothane. These results are discussed in terms of the action of chemical depolarizing drugs such as suxamethonium and acetylcholine. The propagated muscle action potentials produce an increase in the free intracellular calcium concentration which may be self-regenerative, but which may become uncontrollable because of the peculiarities of MH that effect the calcium pump or storage areas.     

Substrate inhibition of beta-lactamases, a method for predicting enzymatic stability of cephalosporins

Selected cephalosporins, including cefamandole, cephaloridine, cephaloglycin, and cefoxitin, were examined for their ability to inhibit the enzymatic activity of and act as substrates for beta-lactamases produced by Enterobacter cloacae and Staphylococcus aureus. Enzyme inhibition was determined by Michaelis-Menten kinetic measurements and by a spot plate assay using a chromogenic substrate (Glaxo compound 87/312). These two methods provide comparable estimates of kinetic parameters. Inhibition of beta-lactamase, as measured by these two methods, was generally found to correlate with resistance to hydrolysis and is proposed as a preliminary method of assessing susceptibility of cephalosporins to beta-lactamase hydrolysis. Four 7-alphaOCH(3), 7-alphaH cephalosporin analogue pairs were also examined. The presence of the 7-alphaOCH(3) substituent invariably resulted in reduced susceptibility to enzymatic hydrolysis, regardless of the other C7 substituent. The 7-alphaOCH(3) compounds were also better inhibitors than were their 7-alphaH analogues, with the exception that 7-alphaOCH(3) compounds having C7 adipic acid substituents were less inhibitory to the S. aureus enzyme than were the corresponding 7-alphaH analogues. Response of these two enzymes to 7-alphaOCH(3) and 7-alphaH cephalosporins suggests that beta-lactamase hydrolysis of these compounds involves attack at the alpha side of the betalactam ring.     

Specific inhibition of hepatic fatty acid synthesis exerted by dietary linoleate and linolenate in essential fatty acid adequate rats

Dietary linoleate and linolenate were investigated for their ability to specifically inhibit liver and adipose tissue lipogenesis in meal-fed (access to food 900-1,200 hr), essential fatty acid (EFA) adequate rats. Supplementing a high carbohydrate diet containing 2.5% safflower oil with 3% palmitate 16:0, oleate 18:1, or linoleate 18:2 did not affect in vivo liver or adipose tissue fatty acid synthesis. However, 18:2 addition to the basal diet did result in a significant (P less than 0.05) decline of liver fatty acid synthetase (FAS) and glucose-6-phosphate dehydrogenase (G6PD) activities. When the safflower oil content of the basal diet was reduced to 1%, the addition of 3% 18:2 or linolenate 18:3 significantly (P less than 0.05) depressed hepatic FAS, G6PD, and in vivo fatty acid synthesis by 50%. Addition of 18:1 caused no depression in hepatic FAS activity but did result in a significant (P less than 0.05) decline in liver G6PD activity and fatty acid synthesis which was intermediate between basal and basal +18:2- or +18:3-fed animals. Adipose tissue rates of lipogenesis were completely unaffected by dietary fatty acid supplementation. Similarly, the addition of 3 or 5% 18:3 to a basal diet for only one meal resulted in no change in lipogenesis relative to that in animals fed the basal diet. The data indicate that, like rats fed EFA-deficient diets, dietary 18:2 and 18:3 exert a specific capacity to depress rat liver FAS and G6PD activities and rate of fatty acid synthesis.     

The wider uses of conjoint psychotherapy

Aged (12- to 14-month-old) C57BL oestrous mice exhibited significantly lower (P less than 0-001) ovarian delta 5-3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) concentration, specific activity and total content than young (3-month-old) oestrous mice, suggesting a decrease in the potential of the older animals to produce ovarian delta 4-3-oxosteroids. Mice in both age groups maintaining pregnancy to 10 or 18 days post coitum (p.c.) had similar values for activity of ovarian 3 beta-HSD. In the aged females in which foetal resorption had occurred, the majority of foetuses had been resorbed by 10 days p.c. However, ovarian 3 beta-HSD activity in these animals was not significantly different from that of young or aged mice maintaining pregnancy. By day 18, however, ovarian dehydrogenase activity in aged females failing to maintain pregnancy had decreased significantly. It is suggested that foetal death in aged mice is not the result of a deficiency in ovarian 3 beta-HSD, but rather may initiate luteal regression and consequently a decline in 3 beta-HSD.     

The specificity of split renal membranes in hereditary nephritis

This study was undertaken to assess the specificity of split renal basement membranes in hereditary nephritis (HN). Thirteen specimens from eight patients with HN were mixed in a random fashion with specimens from control patients with either idiopathic nephrotic syndrome or various forms of glomerulonephritis and with specimens from patients with benign recurrent hematuria (BRH). Each biopsy specimen was scored for splitting of glomerular basement membranes (GBMs). Control and BRH specimens contained focal splitting in the GBMs; the biopsy specimens from HN patients had widespread lesions. Evaluation of split GBMs is useful in differentiating patients with HN from those with BRH and other renal diseases that may be confused with HN.