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This paper gives some examples of the control systems currently operating in the paper and cement industries where CONRAD software is in use. While the primary concern is to show how the various strategies that are required on applications are implemented with CONRAD software, control strategies themselves may be of some interest. The main advantages of digital computer regulation on the majority of processes lie not in the direct replacement of functions, which can be performed by three term analogue controllers, but rather in implementing the type of control that cannot be tackled satisfactorily by analogue control equipment. This includes feedforward, feedback, and multivariable non-interactive control on processes with long time scales and complex transfer functions, particularly where dead times or transport delays are involved.

The problem of plotting on probability paper is extended to continuous distributions which are completely specified except for scale and location parameters. Necessary and sufficient conditions are given to ensure that the plot which is optimal for estimating the scale parameter is also optimal for estimating each of the percentiles.

Wright's model for the effects of random fluctuations in gene frequency in a population of fixed size is generalized to randomly fluctuating population size, and treated from the viewpoint of G. Malécot, using a martingale convergence theorem. The gene frequency approaches a limit, whose value depends on the actual realization, or history, of the process; that is, convergence is with probability one (or: almost surely) in statistical language. The limit does not necessarily represent a state of fixation of either allele; in particular, the limiting probability distribution is not necessarily trivial. For the special case of deterministically varying population size, a necessary and sufficient condition for such non-triviality is given.

In a recent paperf entitled A note on the linear fractional group, Todd obtained an abstract definition for the group LF(2, 2) in terms of n+2 generators. Apparently he gave no consideration to the question of the independence of the defining relations, for they can be considerably simplified. First, in view of the condition RSi = Si+iR (which is the same as i£S0^~* = Si), the three generators U, R and S0 are sufficient to generate the entire group. If we give a definition in teims of these three generators alone, the relations

1. A method has been developed for the estimation of testosterone in human urine by using acid hydrolysis followed by a quantitative form of a modified Girard reaction that separates a ;conjugated-ketone' fraction from a urine extract; this is followed by column chromatography on alumina and paper chromatography. 2. Comparison of methods of estimation of testosterone in the final fraction shows that estimation by gas-liquid chromatography is more reproducible than by colorimetric methods applied to the same eluates from the paper chromatogram. 3. The mean recovery of testosterone by gas-liquid chromatography is 79.5%, and this method appears to be specific for testosterone. 4. The procedure is relatively rapid. Six determinations can be performed by one worker in 2 days. 5. Results of determinations on human urine are briefly presented. In general, they are similar to earlier estimates, but the maximal values are lower.

1. The branched-chain pentose apiose reacts with the benzidine-trichloroacetic acid reagent on paper chromatograms to give a yellow spot with.an intense white fluorescence in ultraviolet light; on chromatograms developed with butanol-acetic acid-water this spot lies between fucose and rhamnose. 2. Examination of paper chromatograms of hydrolysates of whole plant material has shown the presence of a substance with these properties in a wide variety of species. 3. Among the plants examined two members of the Lemnaceae (Lemna minor and Wolffia arrhiza) were found to be especially rich sources, comparable with Posidonia australis (Bell, Hardwick, Isherwood & Cahn, 1954). 4. Measurements of the apiose content of fractions derived from Lemna have shown that the sugar is present at a concentration of about 4% in the holocellulose, and part of this is retained in the alpha-cellulose left by extraction with 24% (w/v) potassium hydroxide containing borate.

1. The lipids of purified human leucocytes were extracted with chloroform-methanol and the extract was washed with water. Glycolipids, isolated by Florisil chromatography, were subjected to mild alkaline hydrolysis and the alkali-resistant fraction was fractionated on a silicic acid column. 2. Three classes of glycolipid were separated. The less polar, containing 3.6% of the total glycolipid hexose as galactose, was tentatively identified as ceramide monohexoside. The major glycolipid fraction was characterized as ceramide dihexosides. The more polar glycolipids comprised 1.6% of the total glycolipid hexose as galactose and glucose (in the molar ratio 2:1) and were non-acidic. This class was separated as a mixture containing ninhydrin-positive glycolipids. 3. The ceramide dihexosides taken from two leucocyte preparations accounted for 15.2% and 16.4% by weight of the total lipids. 4. The carbohydrate moiety of the ceramide dihexosides contained galactose and glucose in the molar ratio 2:1. Partial acid hydrolysis and paper chromatography indicated that the hexoses are present as disaccharides, lactose being identified as one of them. 5. Palmitic acid (C(16:0)) and nervonic acid (C(24:1)) were the major fatty acids of this glycolipid. Hydroxy fatty acids were not detected.

Part of the instrumentation for measurement of pollution from motor vehicles is described. The methods are selected for sensitivity and selectivity and will give a continuous record. Calibration is important and selected example procedures are described. The data-handling problem is overcome by inclusion of a 10-channel logger with punched paper tape output.

The purpose of this short paper is to point out how a slight modification of the formulation of the problem in Brown (1966) yields a variety of admissibility results for problems involving an unknown location or scale parameter. The results sketched, but not proved, include some applications of the analogous two parameter results in Brown and Fox (1974). The applications involve testing problems, estimation problems, and confidence set problems. We treat here only fixed sample size situations; although there also exist similar sequential applications. The proof is essentially that contained in Brown (1966).

1. The phosphate esters of dimethylaminoethanol and monomethylaminoethanol can be incorporated from their cytidine diphosphate esters into the phospholipids of brain and liver dispersions; the deoxycytidine nucleotides of the same bases are less effective precursors. 2. The cytidylyltransferases of brain and liver are less effective in forming the cytidine diphosphate esters of monomethylaminoethanol and dimethylaminoethanol than those of ethanolamine and choline.

1. Incubation conditions were established in experiments with human-prostate homogenates for almost complete conversion of [4-(14)C]testosterone into at least ten transformation products. 2. Whole homogenates of tissue with benign hypertrophy were shown to contain 3alpha-, 3beta- and 17beta-hydroxy steroid dehydrogenases, Delta(4)-3-oxo steroid 5alpha- and 5beta- reductases and unidentified hydroxylases. 3. Most of the 17beta-hydroxy steroid-dehydrogenase activity was located in the mitochondria, which showed little other activity. 4. The 3alpha- and 3beta-hydroxy steroid dehydrogenases and the 5beta-reductase were located in the high-speed supernatant and required supplementation with NADPH for activity. 5. The 5alpha-reductase was located in both microsomal and high-speed supernatant fractions and also required supplementation with NADPH.

1. A rat-liver supernatant preparation can achieve the biological O-sulphation of l-tyrosylglycine and l-tyrosyl-l-alanine at pH7·0. 2. The optimum concentrations of l-tyrosylglycine and l-tyrosyl-l-alanine in this system are 50mm and 60mm respectively. 3. l-Tyrosylglycine yields two sulphated products, whereas l-tyrosyl-l-alanine yields three sulphated products, when used as acceptor for sulphate in the rat-liver system. 4. With both substrates, one of the sulphated products has been identified as the O-sulphate ester of the corresponding parent peptide.

1. The phospholipids from the non-capsulated strain of Pneumococcus I–192R, A.T.C.C. 12213, were separated into three fractions by chromatography on columns of silicic acid and DEAE-cellulose (acetate form). 2. The water-soluble phosphate esters produced by deacylation of each fraction were separated by chromatography on columns of DEAE-cellulose (HCO3− form). 3. Three deacylated products, diglycerol phosphate, glycerylphosphorylglycerol phosphate and bis(glycerylphosphoryl)glycerol, were identified by analysis, by chemical degradations and by comparison with synthetic materials. 4. From a study of freshly isolated lipids prepared and worked up under conditions where exposure to acid was minimal, it was concluded that the Pneumococcus contains phosphatidylglycerol and bisphosphatidylglycerol, in the molar proportion 1:2·5–3·0, and that the deacylation product glycerylphosphorylglycerol phosphate was probably an artifact of the isolation procedure. 5. Acid-catalysed isomerization (phosphodiester migration) of diglycerol phosphate and bis(glycerylphosphoryl)glycerol and transesterification (glycerol phosphate transfer) of diglycerol phosphate were observed. The structures of the products were established by degradation. 6. A novel mechanism for the biosynthesis of bisphosphatidylglycerol is presented.

1. A non-enzymic method for the preparation of adenosine 5′-diphosphate is described, in which the terminal phosphate of adenosine 5′-triphosphate is transferred to methanol in the presence of hydrochloric acid. The final purified product can be obtained in 60% yield. 2. Experiments with [14C]methanol showed that no methylation of the adenosine diphosphate occurs during the reaction. 3. Confirmation that the pyrophosphate moiety of the adenosine diphosphate produced was in the 5′-position was obtained by: (a) periodate oxidation; (b) treatment with apyrase and examination of the resulting adenylic acid isomer by paper chromatography. 4. The method appears to be generally applicable to the preparation of nucleoside 5′-diphosphates from the corresponding nucleoside 5′-triphosphates.

1. A method is described for the quantitative separation of the sulphur compounds in a single sample of tissue by passing an extract through a serial assembly of ion-exchange resins in the order: Dowex 2 (Cl(-) form), Dowex 1 (CO(3) (2-) form), Amberlite CG-50 (H(+) form) and Zeo-Karb 225 (H(+) form). 2. Groups of sulphur amino acids were eluted separately from each column; the recovery of sulphur compounds after their labelling with (35)S in vivo by injection of l-[(35)S]-methionine was 91-106%. Individual sulphur compounds were further resolved by one-dimensional or two-dimensional paper chromatography. 3. Evidence is presented on the occurrence of S-adenosylmethionine and S-adenosylhomocysteine in rat liver and brain. Rat liver and brain contained 83.6 and 31.4mmu-moles/g. respectively of S-adenosylmethionine.

1. l-alpha-Amino[6-(14)C]adipic acid has been prepared from the dl-amino acid by oxidation of the l-isomer with l-amino acid oxidase to alpha-oxo[6-(14)C]adipic acid and by transamination of the latter with l-glutamic acid in an extract of a Cephalosporium sp. prepared by ultrasonic treatment of the mycelium. 2. The optical configuration of small amounts of (14)C-labelled alpha-aminoadipic acid from the mycelium of the Cephalosporium sp. has been determined by treatment with l-amino acid oxidase and measurement of the proportion of radioactivity subsequently retained on a column of a strong cation-exchange resin. 3. alpha-Aminoadipic acid which had been labelled in the mycelium from [1-(14)C]acetate appeared to contain more than 99% of the l-isomer. 4. l-alpha-Amino[(14)C]adipic acid (sodium salt) was taken up much more rapidly than the d-isomer, or alpha-oxo[6-(14)C]adipic acid, by suspensions of washed mycelium of the Cephalosporium sp. in water. The pool of intracellular alpha-aminoadipic acid was expandable. 5. Intracellular products found to be labelled with (14)C from l-alpha-amino[(14)C]adipic acid were delta-aminovaleric acid, saccharopine, lysine, protein, compounds which behaved like penicillin N, cephalosporin C and deacetylcephalosporin C respectively on paper chromatography and electrophoresis, and a peptide whose amino acid residues include alpha-aminoadipic acid, cysteine and valine. 6. l-alpha-Amino[(14)C]adipic acid acted as a precursor of the delta-(d-alpha-aminoadipoyl) side chains of extracellular penicillin N and cephalosporin C. 7. (14)C from d-alpha-amino[(14)C]adipic acid was incorporated into penicillin N and cephalosporin C, but the incorporation was accompanied by a relatively high dilution of specific radioactivity and some l-alpha-amino[(14)C]adipic acid was found in the intracellular pool. 8. These findings are discussed in relation to the origin of the d- configuration of the alpha-aminoadipoyl side chain of the antibiotics.

1. A transfructosylase was separated from Jerusalem artichoke-tuber extracts. The partially purified enzyme was practically free from fructosans and its specific activity was increased more than sevenfold. 2. The enzyme was highly specific for terminal beta-(2-->1')-linked fructofuranosyl residues. 3. The most active donor found was 1(F)-fructosylsucrose, which had about five times the reactivity of the next higher homologues (degree of polymerization 4-6); (1-fructosyl)(2)fructose was intermediate in reactivity; sucrose was inactive. 4. Sucrose, and polymers of high degree of polymerization (>20), were the most efficient acceptors for transferred fructosyl residues of the compounds tested. 5. A variety of transferase activities appeared to be catalysed by the enzyme, namely, dismutation (;self-transfer') giving rise to a series of polymers ranging in degree of polymerization both above and below that of the original substrate, transfer to polymer giving rise to limited quantities of higher polymers, and transfer to sucrose; in the last case 1(F)-fructosylsucrose/sucrose transfer (resulting in exchange labelling of sucrosyl groups) was used to investigate the mechanism of the reaction more fully. 6. Since fructose transfer can be demonstrated in the living plant tissue, the inter-relationships of the various activities and their significance in fructosan metabolism are discussed.

1. A ribonuclease has been partially purified from the cotyledons of germinating seed of Pisum arvense. 2. The enzyme degrades ribopolynucleotides to adenosine 3′-phosphate, guanosine 3′-phosphate and the cyclic nucleotides cytidine 2′,3′-phosphate and uridine 2′,3′-phosphate; no resistant `core' remains. 3. The activity of RNA-degrading enzymes in the cotyledons increases to a maximum during the first 5 days of germination, passes through a minimum around the eighth day, and thereafter increases again. 4. Ion-exchange chromatography of methanol-soluble extracts of cotyledons revealed the presence, amongst other components, of the 2′-, 3′- and 5′-phosphates of cytidine and uridine, the 3′- and 5′-phosphates of adenosine, and guanosine 5′-phosphate. 5. Seed soaked in a solution containing [32P]orthophosphate gave a methanol-soluble fraction containing labelled nucleoside 5′-phosphates, but nucleoside 2′- and 3′-phosphates were not labelled. 6. It is believed that the nucleoside 2′- and 3′-phosphates arise by the action of ribonuclease on cotyledon RNA.

The oligosaccharide units of a type K and a type L IgA immunoglobulin have been examined. The two proteins differed in their content of 6-deoxy-l-galactose and N-acetylneuraminic acid, and in the d-mannose/d-galactose ratio. With glycopeptides prepared from the type K protein, specific glycosidases liberated the N-acetylneuraminic acid and 7-8 residues of 2-acetamido-2-deoxy-d-glucose, and mild acid hydrolysis released most of the 6-deoxy-l-galactose. The type K immunoglobulin appeared to contain 3 oligosaccharide units, whereas the type L protein probably contained 3 or more units.

1. gamma-Ethylideneglutamic acid has been isolated from fruit capsules of tulip plants. 2. The assigned structure was indicated by examining the products formed after oxidation and catalytic hydrogenation and was confirmed by nuclear-magnetic-resonance spectroscopy and by synthesis of gamma-ethylglutamic acid. 3. The ability of gamma-ethylideneglutamic acid to participate in transamination and decarboxylation reactions was examined.