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691.
692.
This paper derives easy-to-calculate preditors for seasonal and nonseasonal fractionally integrated autoregressive-moving average (ARIMA (p, d, q) × (P, D, Q)s) models with both differencing parameters d and D assuming values on the real line. It is shown that these predictors are optimum. Special attention is given to the one-step-ahead predictors as they are constantly in demand in almost every practical situation.  相似文献   
693.
This study was designed to investigate the possible association of high colony counts of legionellae from cooling towers and evaporative condensers with Legionnaires' disease outbreaks. We obtained legionellae counts from samples of cooling towers and evaporative condensers that were the likely sources of two different Legionnaires' disease outbreaks and compared these counts with those from cooling towers that were not associated with reports of human disease. Among 675 potential control cooling tower that were samples from 258 facilities, 136 facilities had one or more cooling towers that met our criteria for inclusion into the study. Samples taken from buildings where an outbreak had occurred had much higherLegionella counts than did samples from other buildings. Colony counts from the two outbreak-associated facilities were significantly higher than colony counts from other facilities [Wilcoxon Rank Sum Test (Exact), p<0.01]. The results of the study suggest that, among cooling towers that test positive for the presence of legionellae, higher colony counts are associated with higher risk of Legionnaires' disease.  相似文献   
694.
We describe a computer model that stimulates a combination of stabilizing and frequency-dependent selection acting on a quantitative character determined by several loci. The results correspond to many features of natural variations at both the phenotypic and genotypic levels. The model is robust, and its results are not strongly dependent either on the nature and shape of the function describing the stabilizing selection, or on the precise form of frequency dependence, except near the extrema. It suggests a mechanism for the maintenance of large amounts of variability, and shows a relation between population size and heterozygosity roughly corresponding to that found in nature. In this respect it is unlike the purely neutral model.  相似文献   
695.
696.
A computer-controlled system for the investigation of the responseproperties of the tibio-femoral chordotonal organ in the locustis described. The computer is used to generate small amplitudesinusoidal movements of the tibia via a small servo-controlledmotor. The resulting response recorded via a suction electrodeis simultaneously detected, processed and stored on disk. Fullconstructional details for all hardware required are given.The software, developed for a BBC microcomputer, in additionto controlling all the hardware, has graphics and analysis routinesenabling the operator to display and manipulate the stored data.  相似文献   
697.
More than 95% of the sequence of human erythrocyte catalase (HEC) has been determined. There are at least 41 differences in sequence between it and that of bovine liver and erythrocyte catalases (BLC and BEC). Although the normal subunit length of BLC is 506 residues, BEC has at least 517 and HEC 520 residues. Most differences between HEC and BLC or BEC are conservative substitutions. If the heme-protein contacts as determined by X-ray crystallography are examined, only one of 39 residues in contact with the heme group differs between HEC and BLC or BEC.  相似文献   
698.
Differentiation of mouse thymus cultured in diffusion chambers   总被引:3,自引:0,他引:3  
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699.
Information is presented concerning revisions of the fermentation air system equipment which improved the sterility situation in the production of monosodium glutamate. Basically, the revision were a relocation and elevation of the intake to the air compressors and installation of a retention chamber after the compressors to take advantage of the heat of compression. The extended high temperature retention ensures sterile air to the final air filter before the fermentor. Contamination losses—mainly from phage—have been materially reduced relative to the level prevailing before the change.  相似文献   
700.
Relative tryptophanyl fluorescence intensities of eleven different proteins (bovine liver glutamate dehydrogenase, bovine pancreas trypsin and α-chymotrypsinogen, egg white lysozyme, ovalbumin, bovine serum albumin and γ-globulin, bovine heart and rabbit muscle lactate dehydrogenases, rabbit muscle glyceraldehyde-3-phosphate dehydrogenase, and yeast alcohol dehydrogenase) were evaluated as a function of the physical state of the protein, i.e., native, denatured with intact disulfide bonds, and denatured with reduced disulfide bonds.  相似文献   
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