The daily metabolic cycle of fully fed, adult white mice, at temperatures from − 8 °C. to 37 °C., averaged 48 ml. of oxygen per mouse per hour between the highest nocturnal and lowest diurnal values, but this value was significantly greater at the higher temperatures. Over the same temperature range, forced activity of mice in a rotating metabolism chamber, up to approximately one-half the maximum running speeds studied, resulted in direct superimposition of work metabolism upon that of rest, with a constant metabolic increment at all temperatures. At the maximum running speeds the metabolism produced by the work decreased with decreasing temperature, with some gain in efficiency. The daily metabolic cycle fell within the activity range in which a given degree of work produced the same increment in oxygen consumption at all temperatures. These studies lead to the hypothesis that, in mice, some of the metabolic components of the daily cycle are additive over the biokinetic range. This results in a very lar...
{"title":"INTERRELATIONS OF DAILY METABOLIC CYCLE, ACTIVITY, AND ENVIRONMENTAL TEMPERATURE OF MICE","authors":"J. Hart","doi":"10.1139/CJR50D-020","DOIUrl":"https://doi.org/10.1139/CJR50D-020","url":null,"abstract":"The daily metabolic cycle of fully fed, adult white mice, at temperatures from − 8 °C. to 37 °C., averaged 48 ml. of oxygen per mouse per hour between the highest nocturnal and lowest diurnal values, but this value was significantly greater at the higher temperatures. Over the same temperature range, forced activity of mice in a rotating metabolism chamber, up to approximately one-half the maximum running speeds studied, resulted in direct superimposition of work metabolism upon that of rest, with a constant metabolic increment at all temperatures. At the maximum running speeds the metabolism produced by the work decreased with decreasing temperature, with some gain in efficiency. The daily metabolic cycle fell within the activity range in which a given degree of work produced the same increment in oxygen consumption at all temperatures. These studies lead to the hypothesis that, in mice, some of the metabolic components of the daily cycle are additive over the biokinetic range. This results in a very lar...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"12 1","pages":"293-307"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76441935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Of 660 cultures of actinomycetes isolated on a nonselective basis from soils from five locations in Northern Canada, 404 strains, or 61.2%, showed antagonism against at least one of eight test organisms consisting of five bacteria and three plant pathogenic fungi. The degree of activity ranged from slight to strong, with the number of test organisms inhibited by any single culture varying from one to six. In all, 49 different antibiotic spectra were observed. Activity against one or more of the pathogenic fungi was shown by 138 cultures, 20.9% of the isolates. The percentage of active cultures was greater, and the degree of inhibition much more marked, against Helminthosporium sativum than against Fusarium culmorum or Fusarium lini. The percentage of active isolates varied with the location and with the depth of the soil. It is suggested that the high proportion of actinomycetes with antagonistic properties occurring in northern soils may be related to the lower degree of plant development in such regions.
{"title":"A study of the antibiotic activity of actinomycetes from soils of northern Canada.","authors":"G. B. Landerkin, Jane R. G. Smith, A. Lochhead","doi":"10.1139/CJR50C-042","DOIUrl":"https://doi.org/10.1139/CJR50C-042","url":null,"abstract":"Of 660 cultures of actinomycetes isolated on a nonselective basis from soils from five locations in Northern Canada, 404 strains, or 61.2%, showed antagonism against at least one of eight test organisms consisting of five bacteria and three plant pathogenic fungi. The degree of activity ranged from slight to strong, with the number of test organisms inhibited by any single culture varying from one to six. In all, 49 different antibiotic spectra were observed. Activity against one or more of the pathogenic fungi was shown by 138 cultures, 20.9% of the isolates. The percentage of active cultures was greater, and the degree of inhibition much more marked, against Helminthosporium sativum than against Fusarium culmorum or Fusarium lini. The percentage of active isolates varied with the location and with the depth of the soil. It is suggested that the high proportion of actinomycetes with antagonistic properties occurring in northern soils may be related to the lower degree of plant development in such regions.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"34 1","pages":"690-698"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78074494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antibiotic XG has been studied for its possible application as a pea seed treatment in the control of Ascochyta leaf and pod spot. Fungistatic properties of Antibiotic XG against Ascochyta Pisi at various concentrations in relation to pH and temperature in vitro were studied. At antibiotic concentrations up to 1 p.p.m. no fungistatic effect was observed at pH values from 3.5 to 6.5, but, at concentrations above 1 p.p.m., complete inhibition of growth was found at all pH values tested. In the temperature range of 22 °C. to 30 °C. antibiotic concentrations of 1 p.p.m. had no effect on growth. Fungicidal activity to spores of A. Pisi has also been tested. A spore suspension of 10,000 spores per ml. required an exposure of 12 hr. with an antibiotic concentration of 100 p.p.m. for complete lethal dosage. The soaking of diseased pea seed samples in Antibiotic XG at a concentration of 25 p.p.m. for a period of 18 hr. effectively controls A. Pisi infection as determined by laboratory test and does not seriously i...
{"title":"ANTIBIOTIC XG AS A SEED TREATMENT FOR THE CONTROL OF LEAF AND POD SPOT OF PEAS CAUSED BY ASCOCHYTA PISI","authors":"V. Wallen, A. J. Skolko","doi":"10.1139/CJR50C-038","DOIUrl":"https://doi.org/10.1139/CJR50C-038","url":null,"abstract":"Antibiotic XG has been studied for its possible application as a pea seed treatment in the control of Ascochyta leaf and pod spot. Fungistatic properties of Antibiotic XG against Ascochyta Pisi at various concentrations in relation to pH and temperature in vitro were studied. At antibiotic concentrations up to 1 p.p.m. no fungistatic effect was observed at pH values from 3.5 to 6.5, but, at concentrations above 1 p.p.m., complete inhibition of growth was found at all pH values tested. In the temperature range of 22 °C. to 30 °C. antibiotic concentrations of 1 p.p.m. had no effect on growth. Fungicidal activity to spores of A. Pisi has also been tested. A spore suspension of 10,000 spores per ml. required an exposure of 12 hr. with an antibiotic concentration of 100 p.p.m. for complete lethal dosage. The soaking of diseased pea seed samples in Antibiotic XG at a concentration of 25 p.p.m. for a period of 18 hr. effectively controls A. Pisi infection as determined by laboratory test and does not seriously i...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"20 1","pages":"623-636"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89640192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A volumetric procedure is described for determining small amounts of iridium (from 2 to 20 mgm.). A solution of the metal is heated to dense fumes with sulphuric acid, cooled, diluted with water, and then oxidized with an excess of cerium (IV) sulphate solution. The resultant solution is titrated with a standard 0.01 N iron (II) sulphate solution, the course of the titration being followed potentiometrically. In solutions containing other platinum metals it has been found possible to determine iridium directly in some cases by this procedure; in other cases it was found necessary to remove osmium as the volatile tetroxide prior to oxidizing with cerium (IV) sulphate. The method is probably less accurate than existing gravimetric procedures, but offers considerable advantage in simplicity.
{"title":"VOLUMETRIC DETERMINATION OF SMALL AMOUNTS OF IRIDIUM","authors":"W. Mcbryde, M. Cluett","doi":"10.1139/CJR50B-096","DOIUrl":"https://doi.org/10.1139/CJR50B-096","url":null,"abstract":"A volumetric procedure is described for determining small amounts of iridium (from 2 to 20 mgm.). A solution of the metal is heated to dense fumes with sulphuric acid, cooled, diluted with water, and then oxidized with an excess of cerium (IV) sulphate solution. The resultant solution is titrated with a standard 0.01 N iron (II) sulphate solution, the course of the titration being followed potentiometrically. In solutions containing other platinum metals it has been found possible to determine iridium directly in some cases by this procedure; in other cases it was found necessary to remove osmium as the volatile tetroxide prior to oxidizing with cerium (IV) sulphate. The method is probably less accurate than existing gravimetric procedures, but offers considerable advantage in simplicity.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"5 1","pages":"788-798"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87905806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The main factors that influence the production of proteolytic enzymes by a few selected cultures have been studied. The time taken to reach the maximum yield of proteases is dependent upon the growth rate of each organism, and varies from two to five days. The fungi tested require the presence of an easily available carbohydrate source in addition to a protein substrate in order to produce high yields of proteolytic enzymes. The Streptomyces cultures will produce proteases in the absence of a carbohydrate source, but yields are generally low. The fungi studied will not produce significant amounts of proteases when grown on predominately inorganic nitrogen sources in contrast with the Streptomyces cultures, one of which produced almost as high yields of proteolytic enzymes when grown with sodium nitrate as when grown with Klim. Of a number of protein sources Klim and malt sprouts provided the best media for protease production. The temperature of incubation and pH of the culture medium are also important f...
{"title":"THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: II. FACTORS AFFECTING THE PRODUCTION OF PROTEASES IN SUBMERGED CULTURE","authors":"W. Dion","doi":"10.1139/CJR50C-035","DOIUrl":"https://doi.org/10.1139/CJR50C-035","url":null,"abstract":"The main factors that influence the production of proteolytic enzymes by a few selected cultures have been studied. The time taken to reach the maximum yield of proteases is dependent upon the growth rate of each organism, and varies from two to five days. The fungi tested require the presence of an easily available carbohydrate source in addition to a protein substrate in order to produce high yields of proteolytic enzymes. The Streptomyces cultures will produce proteases in the absence of a carbohydrate source, but yields are generally low. The fungi studied will not produce significant amounts of proteases when grown on predominately inorganic nitrogen sources in contrast with the Streptomyces cultures, one of which produced almost as high yields of proteolytic enzymes when grown with sodium nitrate as when grown with Klim. Of a number of protein sources Klim and malt sprouts provided the best media for protease production. The temperature of incubation and pH of the culture medium are also important f...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"1 1","pages":"586-599"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76453243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A series of nine delicate species, for the most part inconspicuous forms, which seem related to the more typical members of Bourdot and Galzin's section Athele of the genus Corticium are described and illustrated. The general features of the group are discussed as well as the possible interrelations of the species described.
{"title":"STUDIES OF CANADIAN THELEPHORACEAE: VII. SOME NEW SPECIES OF CORTICIUM, SECTION ATHELE","authors":"H. S. Jackson","doi":"10.1139/CJR50C-045","DOIUrl":"https://doi.org/10.1139/CJR50C-045","url":null,"abstract":"A series of nine delicate species, for the most part inconspicuous forms, which seem related to the more typical members of Bourdot and Galzin's section Athele of the genus Corticium are described and illustrated. The general features of the group are discussed as well as the possible interrelations of the species described.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"25 1","pages":"716-725"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83294549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wheat straw holocellulose, after soaking in liquid ammonia for 36 hr. at room temperature, was fractionated by successive extractions with cold water, 0.5% sodium carbonate, 0.5% potassium hydroxide, and 2.2% potassium hydroxide. Pretreatment with liquid ammonia increased the material soluble in cold water from 3% to 20.2%. Hemicellulose fractions were precipitated from the extracts by ethanol. A complete analytical balance was obtained by estimating ash, pentosan, uronic acid anhydride, acetyl, and methoxyl contents of the original holocellulose, of each of the fractions and of the residue. Analyses of the isolated fractions showed some systematic differences, with pentosan contents increasing and uronic acid anhydride decreasing progressively in the alkali soluble fractions. D-xylose, L-arabinose, D-glucose, D-galactose, and hexuronic acid in approximate molar ratios of 40:7:2:1:4 were found in the hemicellulose fractions. The presence of the sugars was confirmed by isolation of crystalline derivatives....
{"title":"USE OF LIQUID AMMONIA IN THE FRACTIONATION OF WHEAT STRAW HOLOCELLULOSE","authors":"C. T. Bishop, G. Adams","doi":"10.1139/CJR50B-093","DOIUrl":"https://doi.org/10.1139/CJR50B-093","url":null,"abstract":"Wheat straw holocellulose, after soaking in liquid ammonia for 36 hr. at room temperature, was fractionated by successive extractions with cold water, 0.5% sodium carbonate, 0.5% potassium hydroxide, and 2.2% potassium hydroxide. Pretreatment with liquid ammonia increased the material soluble in cold water from 3% to 20.2%. Hemicellulose fractions were precipitated from the extracts by ethanol. A complete analytical balance was obtained by estimating ash, pentosan, uronic acid anhydride, acetyl, and methoxyl contents of the original holocellulose, of each of the fractions and of the residue. Analyses of the isolated fractions showed some systematic differences, with pentosan contents increasing and uronic acid anhydride decreasing progressively in the alkali soluble fractions. D-xylose, L-arabinose, D-glucose, D-galactose, and hexuronic acid in approximate molar ratios of 40:7:2:1:4 were found in the hemicellulose fractions. The presence of the sugars was confirmed by isolation of crystalline derivatives....","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"1 1","pages":"753-761"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79775010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The copper salts of the basic amino acids (arginine, histidine, lysine, and ornithine) are formulated as complex salts. They contain a cation (with two positive charges) consisting of a copper atom and two amino acid molecules. The anion can be a simple inorganic group, such as Cl−, NO3−, SO4=. The complex copper amino acid cations form double complex compounds with anions HgI3− or HgI4=. The double complex salts of arginine, [Cu(C6H14O2N4)2][HgI4], and lysine, [Cu(C6H14O2N2)2][HgI3]2, are only slightly soluble in water and have characteristic crystal forms. They can be used for the quantitative determination of these amino acids. The copper salts of the natural amino acids are classified into four groups.
{"title":"THE NEW COMPLEX COMPOUNDS OF ARGININE AND LYSINE","authors":"A. Taurins","doi":"10.1139/CJR50B-094","DOIUrl":"https://doi.org/10.1139/CJR50B-094","url":null,"abstract":"The copper salts of the basic amino acids (arginine, histidine, lysine, and ornithine) are formulated as complex salts. They contain a cation (with two positive charges) consisting of a copper atom and two amino acid molecules. The anion can be a simple inorganic group, such as Cl−, NO3−, SO4=. The complex copper amino acid cations form double complex compounds with anions HgI3− or HgI4=. The double complex salts of arginine, [Cu(C6H14O2N4)2][HgI4], and lysine, [Cu(C6H14O2N2)2][HgI3]2, are only slightly soluble in water and have characteristic crystal forms. They can be used for the quantitative determination of these amino acids. The copper salts of the natural amino acids are classified into four groups.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"4 1","pages":"762-769"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85269082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In comparative tests for ascospore formation by 43 different yeast strains a solid medium containing acetate and dextrose was shown to be superior to two other sporulation media. Ascospores were formed more frequently and in greater numbers on the former medium. Eleven cultures of the thirty forming ascospores on acetate–dextrose agar yielded 50% or more asci, and seven cultures formed asci only on this agar medium.
{"title":"A COMPARATIVE STUDY OF ASCOSPORE FORMATION BY 43 YEAST CULTURES","authors":"A. M. Adams","doi":"10.1139/CJR50F-037","DOIUrl":"https://doi.org/10.1139/CJR50F-037","url":null,"abstract":"In comparative tests for ascospore formation by 43 different yeast strains a solid medium containing acetate and dextrose was shown to be superior to two other sporulation media. Ascospores were formed more frequently and in greater numbers on the former medium. Eleven cultures of the thirty forming ascospores on acetate–dextrose agar yielded 50% or more asci, and seven cultures formed asci only on this agar medium.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"144 1","pages":"413-416"},"PeriodicalIF":0.0,"publicationDate":"1950-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77491135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Meat from pigs slaughtered in a fatigued condition, as in present packing house procedures, had a lower glycogen reserve than meat from animals that had been fed and rested. Post-mortem breakdown of glycogen to lactic acid lowered the pH of meat from fed animals to approximately 5.3 while that from fatigued animals remained at about 6.0 or even as high as 6.6. Meat of low pH contained less sodium nitrite immediately after cure, and retained the desirable red color of cut lean surfaces much longer than did meal of high pH. Meal of low pH was also less susceptible to spoilage by bacteria. Color differences were less apparent after the meat had been smoked, and the preslaughter treatment of the pigs is therefore of less importance in the production of smoked products. The quality of unsmoked Wiltshire skies, on the other hand, would be greatly improved by proper preslaughter handling of the pigs.
{"title":"Effect of ante-mortem treatment of pigs on the quality of Wiltshire bacon.","authors":"N. Gibbons, D. Rose","doi":"10.1139/CJR50F-039","DOIUrl":"https://doi.org/10.1139/CJR50F-039","url":null,"abstract":"Meat from pigs slaughtered in a fatigued condition, as in present packing house procedures, had a lower glycogen reserve than meat from animals that had been fed and rested. Post-mortem breakdown of glycogen to lactic acid lowered the pH of meat from fed animals to approximately 5.3 while that from fatigued animals remained at about 6.0 or even as high as 6.6. Meat of low pH contained less sodium nitrite immediately after cure, and retained the desirable red color of cut lean surfaces much longer than did meal of high pH. Meal of low pH was also less susceptible to spoilage by bacteria. Color differences were less apparent after the meat had been smoked, and the preslaughter treatment of the pigs is therefore of less importance in the production of smoked products. The quality of unsmoked Wiltshire skies, on the other hand, would be greatly improved by proper preslaughter handling of the pigs.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"223 1","pages":"438-450"},"PeriodicalIF":0.0,"publicationDate":"1950-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85926995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：