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An agar-sheet method of testing the efficiency of seed treating machines. 检验种子处理机效率的琼脂片法。
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-047
J. Machacek
{"title":"An agar-sheet method of testing the efficiency of seed treating machines.","authors":"J. Machacek","doi":"10.1139/CJR50C-047","DOIUrl":"https://doi.org/10.1139/CJR50C-047","url":null,"abstract":"The efficiency of a seed treating machine depends to a considerable extent on the uniformity with which the fungicide used for treatment is mixed with the seed. The uniformity of treatment may be ascertained by placing treated seeds, at 2-in. intervals, on large sheets of inoculated potato-sucrose agar. In the preparation of these sheets, melted, acidified agar is poured in a uniform layer over panes of glass and, when the agar has solidified, it is dusted heavily with spores of Penicillium purpurogenum Stoll. After the treated seed is placed on the agar, the culture is covered with a sheet of glass and incubated for two days at room temperature. The uniformity of treatment may then be determined from the variability in diameter of the zones of inhibition around the seeds. This technique may also be used for determining the comparative potency of different fungicides, and the rate at which they are lost from the seed.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"13 1","pages":"739-744"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82845240","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}
引用次数: 10
FLOCCULATION IN SUSPENSIONS OF LARGE PARTICLES 大颗粒悬浮液中的絮凝作用
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50B-095
S. G. Mason, C. Hubley, A. Robertson
{"title":"FLOCCULATION IN SUSPENSIONS OF LARGE PARTICLES","authors":"S. G. Mason, C. Hubley, A. Robertson","doi":"10.1139/CJR50B-095","DOIUrl":"https://doi.org/10.1139/CJR50B-095","url":null,"abstract":"Based upon an assumed mechanism of particle aggregation by shear-induced interparticle collisions, a new method of studying flocculation in suspensions of large particles is described, and representative results obtained with cellulose–fiber suspensions are presented. The method consists in subjecting the suspension to a reproducible condition of shear motion and analyzing the fluctuations in optical transmission coefficient electronically. An approximate statistical theory is presented on the basis of which a flocculation index (σ/N0) appropriate to the method is proposed. The index is a function of both the number and size of the aggregates. The flocculation index was found to decrease with increasing rate of shear and decreasing fiber length. The effect of concentration and of additives was investigated. Alternative experimental techniques are outlined and limitations to the present method are pointed out.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"117 1","pages":"770-787"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78317635","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}
引用次数: 10
Qualitative and quantitative determination of the wheat leaf carbohydrates. 小麦叶片碳水化合物的定性和定量测定。
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-049
D. Roberts
{"title":"Qualitative and quantitative determination of the wheat leaf carbohydrates.","authors":"D. Roberts","doi":"10.1139/CJR50C-049","DOIUrl":"https://doi.org/10.1139/CJR50C-049","url":null,"abstract":"The nonreducing sugar in wheat leaves is probably entirely sucrose. It is the only abundant sugar. Free reducing sugars are absent, or almost absent from wheat leaves grown under the conditions described. The reducing power in the cleared alcoholic extracts of the leaves is, at least, partly due to degradation products of ascorbic acid. Other nonsugar reducing substances also are apparently present. The alcohol insoluble residue from wheat leaves contains little or no fructosan, dextrin, or starch at the two and one-half week old stage. Satisfactory methods for extracting and determining the sucrose are described. The following methods gave satisfactory results with wheat leaf extracts: the reducing power methods of Hanes and Somogyi after acid or preferably invertase hydrolysis, Ost's solution for fructose residues, the method of Neuberg and Strauss, the colorimetric resorcinol method. The latter method gives only approximate values for fructose residues unless the sugar concentration is high; the method...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"55 6 1","pages":"754-779"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90010266","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}
引用次数: 9
NUTRITIONAL REQUIREMENTS OF PSEUDOMONAS NIGRIFACIENS AS RELATED TO GROWTH AND PIGMENT PRODUCTION 与生长和色素产生有关的黑假单胞菌的营养需求
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-044
H. Katznelson, A. H. White
{"title":"NUTRITIONAL REQUIREMENTS OF PSEUDOMONAS NIGRIFACIENS AS RELATED TO GROWTH AND PIGMENT PRODUCTION","authors":"H. Katznelson, A. H. White","doi":"10.1139/CJR50C-044","DOIUrl":"https://doi.org/10.1139/CJR50C-044","url":null,"abstract":"The organic and inorganic requirements were determined for growth and pigment production by Pseudomonas nigrifaciens, an organism causing a reddish brown discoloration on the surface of mildly salted butter. Amino acids such as alanine, asparagine, proline, or glutamic acid were the best source of nitrogen for both growth and pigment production in a synthetic medium containing sodium chloride, inorganic salts, and glycerol; however, a carbohydrate was required only for pigment production in this amino acid medium. Na, K, Mg, S, P, and Cl or Br were also essential for both growth and pigmentation, larger amounts of these elements usually being required for synthesis of pigment than for growth. The dark brown-purple pigment produced was insoluble in all the common organic solvents hot or cold. With proline as a source of nitrogen a reddish-purple pigment developed which became deep purple then a deep brown purple. It is suggested that two pigments may be formed; one, a melanin-like dark brown substance orig...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"97 1","pages":"706-715"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91465678","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}
引用次数: 6
PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XXXVII. A STUDY OF FACTORS AFFECTING THE BACILLUS SUBTILIS FERMENTATION 2,3-丁二醇的制备及性质枯草芽孢杆菌发酵影响因素的研究
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-037
A. Blackwood, F. J. Simpson
{"title":"PRODUCTION AND PROPERTIES OF 2,3-BUTANEDIOL: XXXVII. A STUDY OF FACTORS AFFECTING THE BACILLUS SUBTILIS FERMENTATION","authors":"A. Blackwood, F. J. Simpson","doi":"10.1139/CJR50C-037","DOIUrl":"https://doi.org/10.1139/CJR50C-037","url":null,"abstract":"The optimum temperature for fermentation of seven strains of the Ford type of Bacillus subtilis is close to 45 °C. At these higher temperatures 10% glucose or equivalent hydrolyzed molasses ferments completely in six days while 10% fructose takes only three days. The rate of fermentation is similar under aerobic or anaerobic conditions but agitation or shallow layers of media increase this rate. The yields of 2,3-butanediol, acetoin, glycerol, and lactic acid are high under anaerobic conditions but in the presence of oxygen the yield of glycerol and lactic acid is decreased. The organism demonstrates strong oxidative tendencies and can give a large yield of acetoin. Other factors affecting the fermentation are also assessed.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"119 1","pages":"613-622"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75248137","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}
引用次数: 0
THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: III. SOME CHARACTERISTICS OF EXTRACELLULAR PROTEASES PRODUCED IN SUBMERGED CULTURE 微生物的蛋白水解酶;细胞外蛋白酶在深层培养中的一些特性
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-036
W. Mcconnell
{"title":"THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: III. SOME CHARACTERISTICS OF EXTRACELLULAR PROTEASES PRODUCED IN SUBMERGED CULTURE","authors":"W. Mcconnell","doi":"10.1139/CJR50C-036","DOIUrl":"https://doi.org/10.1139/CJR50C-036","url":null,"abstract":"Some of the general characteristics of the proteases liberated into the culture medium by molds and actinomycetes grown in submerged culture have been studied. Species of Alternaria, Streptomyces, Mortierella, and Gliocladium were used. The enzymes resemble trypsin in that they are most active at a pH slightly above 7 and are inhibited by a preparation of egg albumin. They are stable at low temperatures but suffer marked losses in activity when stored for 16 hr. above 40 °C. The most rapid hydrolysis of gelatin occurs at temperatures between 40 °C. and 50 °C. The enzymes from different organisms show definite differences with respect to their ability to attack different proteins, gelatin and casein being in general the most readily digested. The protease systems from different organisms also vary with respect to the extent to which they can digest gelatin; some enzymes are able to release about three times as many amino groups from gelatin as others. The limit of the hydrolysis is not dependent upon subst...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"40 1","pages":"600-612"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85764654","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}
引用次数: 8
ON THE FRICTION OF VARIOUS SYNTHETIC AND NATURAL RUBBERS ON ICE 各种合成橡胶和天然橡胶在冰上的摩擦
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50F-044
P. Pfalzner
{"title":"ON THE FRICTION OF VARIOUS SYNTHETIC AND NATURAL RUBBERS ON ICE","authors":"P. Pfalzner","doi":"10.1139/CJR50F-044","DOIUrl":"https://doi.org/10.1139/CJR50F-044","url":null,"abstract":"The dynamic and static friction on ice, the hardness, and the resilience of natural and synthetic rubber tire compounds were measured. General relationships were found to exist between friction and hardness of the rubber, friction and ice temperature, hardness and temperature, hardness and age of the rubber, resilience and hardness. Extraction of the rubber had a variable effect.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"6 1","pages":"468-489"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88769582","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}
引用次数: 13
Studies in Septoria lycopersici Speg. 番茄紫霉的研究。
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-040
B. Macneill
{"title":"Studies in Septoria lycopersici Speg.","authors":"B. Macneill","doi":"10.1139/CJR50C-040","DOIUrl":"https://doi.org/10.1139/CJR50C-040","url":null,"abstract":"Investigations into the biology of Septoria lycopersici Speg., a leaf-spotting fungus parasite of the tomato, reveal that this fungus species is composed of at least two physiologic races which show both qualitative and quantitative differences in their pathogenicity. Other factors, such as humidity, temperature, light, and host nutrition, which influence host–parasite interaction, have been shown to cause further variability in the symptomatological picture. Studies of spore germination and the prepenetration phase of host–parasite relationships suggest an interaction before actual penetration which, in some cases, is sufficient to condition the germination of the spores themselves. A minimum period of 48 hr. at saturation is required to promote germination and stomatal penetration, but this experience at high humidity need not be continuous. The fungus inhabits an intercellular locus, but is very intimately associated with the cells of the tissues parasitized. There is no evidence of action in advance; ...","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"8 1","pages":"645-672"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88866708","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}
引用次数: 15
INTERRELATIONS OF DAILY METABOLIC CYCLE, ACTIVITY, AND ENVIRONMENTAL TEMPERATURE OF MICE 小鼠日常代谢周期、活动与环境温度的相互关系
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50D-020
J. Hart
{"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}
引用次数: 46
THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: I. SURVEY OF FUNGI AND ACTINOMYCETES FOR PROTEASE PRODUCTION IN SUBMERGED CULTURE 微生物的蛋白水解酶:i.真菌和放线菌在深层培养中生产蛋白酶的调查
Canadian journal of research Pub Date : 1950-12-01 DOI: 10.1139/CJR50C-034
W. Dion
{"title":"THE PROTEOLYTIC ENZYMES OF MICROORGANISMS: I. SURVEY OF FUNGI AND ACTINOMYCETES FOR PROTEASE PRODUCTION IN SUBMERGED CULTURE","authors":"W. Dion","doi":"10.1139/CJR50C-034","DOIUrl":"https://doi.org/10.1139/CJR50C-034","url":null,"abstract":"Of 289 fungi and actinomycetes tested, only 20 were found to produce high yields of proteolytic enzymes when grown in submerged culture. Strains of Gliocladium roseum and Alternaria tenuis were found to be consistently proteolytic, and other good strains were also found in the genera Chaetomium, Sordaria, Epicoccum, Rhizoctonia, and Streptomyces.","PeriodicalId":9392,"journal":{"name":"Canadian journal of research","volume":"162 1","pages":"577-585"},"PeriodicalIF":0.0,"publicationDate":"1950-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91208535","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}
引用次数: 18
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