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Showing papers by "University of Guelph published in 1972"


Journal ArticleDOI
TL;DR: It was confirmed that the lactobacilli are the only group of organisms generally present in the small intestine in numbers exceeding 104/g, and during the growth of the bird the flora changed.
Abstract: Synopsis A study has been made of the intestinal flora of chickens aged between 2 and 6½ weeks. No major differences were found when rations containing 9 or 25% fish meal were compared or when two different sources of fish meal were used. Throughout the period investigated, it was confirmed that the lactobacilli are the only group of organisms generally present in the small intestine in numbers exceeding 104/g. Clostridia were regularly found at 102 to 104/g, but Clostridium welchii was isolated from only occasional samples. In the caeca, the total number of bacteria present at 2, 3, 4 and 6½ weeks was about 1011/g. Of these it was generally possible to isolate more than 20% using an anaerobic roll‐tube technique and oxygen‐free CO2. Many different types of anaerobes were isolated including strictly anaerobic budding bacteria which had not previously been studied. During the growth of the bird the flora changed. Anaerobic streptococci (peptostreptococci) predominated at 2 weeks but gradually decreased so ...

319 citations



Journal ArticleDOI
TL;DR: Meningeal worm can apparently have considerable impact on moose populations in endemic areas and the existence of clinical disease in moose in an area should be regarded as evidence of a much more widespread disease problem which may have eventually a serious impact on the population.
Abstract: The author reviews the relationship of meningeal worm (Parelapostrongylus tenuis) and its usual host, the white-tailed deer (Odocoileus virginianus). Important alterations in the environment in the past 100 years have greatly expanded the northern range of white-tailed deer and brought host and parasite into contact with other native cervids such as moose (Alces americana), mule deer (Odocoileus hemionus), and woodland caribou (Rangfier tarandus) in which meningeal worm is highly pathogenic. There is evidence the parasite is spreading westward with deer in the aspen-parklands of Canada. Meningeal worm can apparently have considerable impact on moose populations in endemic areas. Possibly the existence of clinical disease in moose in an area should be regarded as evidence of a much more widespread disease problem which may have eventually a serious impact on the population.

117 citations


Journal ArticleDOI
TL;DR: During a 3-year study in Nairobi National Park, 1965–1968, 250 giraffe were identified by their neck markings, including the relationships between particular individuals, and population information collected included the times of calving, the growth and longevity of giraffe, their reproductive potential and the age structure of the population.
Abstract: Summary During a 3-year study in Nairobi National Park, 1965–1968, 250 giraffe were identified by their neck markings. The herd structure of these animals was studied, including the relationships between particular individuals. Population information collected included the times of calving, the growth and longevity of giraffe, their reproductive potential, the age structure of the population and its density. Immigration, emigration and home range studies were completed with the help of radio telemetry equipment. The effect of giraffe on the vegetation and the possibility of giraffe surviving without free water are discussed.

110 citations


Journal ArticleDOI
TL;DR: Both enzyme activities were very much higher in the Vantress × W.P.R. chicks than in the parent (White Plymouth Rock) strain, but the former birds were less affected by thyrocasein.

79 citations


Journal ArticleDOI
TL;DR: It is suggested that the hydrogenation process results in tallow with physical form which resists dispersion and hydrolysis in the rumen and solubilization in the small intestine in order to facilitate adaptation of sheep to fat-supplemented diets.
Abstract: A TOTAL of 28 crossbred wethers were used in two experiments to determine the digestibilty of hydrogenated tallow-, saturated fatty acidsand soybean oil-supplemented diets. Digestibility values for individual fats were determined by subtracting from total dietary lipid and fecal output the dietary and fecal lipids measured with basal diets. In the first experiment addition of 3% flaked, hydrogenated tallow to a basal diet resulted in lower digestibility (34%) for the tallow compared with soybean oil (98%). In the second experiment, hydrogenated tallow was added to a basal diet at approximately the 4.8% level either in dry flaked form or melted and mixed (blended) into the concentrate portion of the basal diet. A further treatment comparison involved addition of saturated free fatty acids at approximately the 4.8% level to the basal diet. Tenday digestion trials were conducted starting at 10 and again at 35 days of this experiment to measure adaptation of sheep to fat-supplemented diets. Melting and mixing the tallow into the diet resulted in significant (P< .01) improvement in digestibility over flaked tallow (40% vs. 30%). Saturated fatty acids were significantly (P<.01) better digested (73%) than either form of tallow. Blood plasma lipid fatty acid levels of sheep reflected these differences in digestibility after 33 days on feed. It is suggested that the hydrogenation process results in tallow with physical form which resists dispersion and hydrolysis in the rumen and solubilization in the small intestine. Additions of soybean oil, saturated fatty acids and hydrogenated tallow tended to lower digestibilities of crude fiber and acid detergent fiber. The decreases were significant

70 citations


Journal ArticleDOI
TL;DR: In this article, the authors examined pseudo-potentials which approximate the formation of a valence set of basis functions which are orthogonal and non-interacting with the core, and which simulate the core in 'valence-orbital only' calculations.
Abstract: Examination is made of inner (core) and outer-shell (valence) separation in molecular orbital calculations. Assuming a set of simple Slater type functions, pseudo-potentials are examined which approximate the formation of a valence set of basis functions which are orthogonal and non-interacting with the core, and which simulate the core in ‘valence-orbital only’ calculations. The simplest form of this potential is , where Δαi is the overlap between valence orbital i and core orbital α and F αα, the diagonal element of the Fock matrix for core orbital α, is estimated from atomic X-ray terms or fitted empirically from model diatomic calculations. Errors introduced by dropping explicit consideration of core orbitals in the formation of the Fock matrix elements for valence orbitals are not small, but can be compensated for in adjustments of F αα in approximate formulations. The total energy is examined and it is found that the ‘valence-orbital only’ energy gives a rather accurate description of the system ene...

61 citations


Journal ArticleDOI
TL;DR: In this paper, the Bourbaki conventions for rings and modules are used for associative and unital modules, where all rings are associative but not necessarily commutative and all modules are unital.
Abstract: In this paper we use the Bourbaki conventions for rings and modules: all rings are associative but not necessarily commutative and have an identity element; all modules are unital.

61 citations


Journal ArticleDOI
TL;DR: Results indicated close relationships between R. lupini and R. japonicum, and (with less certainty) betweenR.
Abstract: Deoxyribonucleic acid (DNA) was isolated from 20 strains of Rhizobium and Agrobacterium and from one strain of Serratia marcescens; the guanine plus cytosine content of each DNA sample was determined by thermal denaturation. Radioactive DNA was isolated from three reference strains following the uptake of [2-14C]thymidine in the presence of deoxyadenosine. Ribonucleic acid (RNA) polymerase was used to synthesize radioactive RNA on DNA templates from the three reference strains. Radioactive DNA and RNA from the three reference strains were each hybridized with filter-bound DNA from all of the 21 test strains in 6 × SSC (standard saline citrate) and 50% formamide at 43 C for 40 hr. DNA/DNA relatedness was also determined by spectrophotometric measurement of the rates of association of single-stranded DNA. The order of relatedness between strains was similar by each method. Overall standard deviations for the DNA/DNA and DNA/RNA membrane filter techniques were ±0.87 and ±1.03%, respectively; that for the spectrophotometric technique was ±4.11%. The DNA/DNA membrane technique gave higher absolute values of hybridization than did the DNA/RNA technique. R. leguminosarum and R. trifolii could not be distinguished from each other by these techniques. These results also indicated close relationships between R. lupini and R. japonicum, and (with less certainty) between R. meliloti and R. phaseoli. Of all the rhizobia tested against the A. tumefaciens 371 reference strain, the R. japonicum strains were the most unrelated. The three Agrobacterium strains used were as related to the R. lupini and R. leguminosarum references as were several rhizobium strains.

61 citations


Journal ArticleDOI
TL;DR: In this paper, a thermoplastic extrusion was employed to produce an experimental texturized soybean product and the physical properties relative to process temperature were examined by test methods which yielded information on product density, shear strength, work of shearing, break elongation, breaking strength, stress relaxation and water regain.
Abstract: Thermoplastic extrusion was employed to produce an experimental texturized soybean product. Physical properties relative to process temperature were examined by test methods which yielded information on product density, shear strength, work of shearing, break elongation, breaking strength, stress relaxation and water regain. Light and scanning electron microscopy were employed to examine product structure. Shear force and work (Kramer Shear Press) and product density were affected markedly by process temperature, showing an increase in the former two and a decrease in the latter with increasing process temperature. Breaking strength (Instron), shear force (Warner-Bratzler Shear) and water regain were also affected but demonstrated more complex relationships. The photomicrographs obtained showed clearly the physical changes which occurred during processing and indicated that, under our experimental conditions, maximum texturization occurred between 175°C and 192°C.

54 citations


Journal ArticleDOI
D. Arthur1
TL;DR: The selenium content of a variety of foods consumed by Canadians was determined by fluorometric chemical analysis as mentioned in this paper, which showed that foods prepared from grains grown in Ontario (C) contained less Se than those from grains of the prairie provinces (W).
Abstract: The selenium content of a variety of foods consumed by Canadians was determined by fluorometric chemical analysis. Breakfast cereals varied widely in their Se content with species of grain and geographical origin. Average values for corn and rice products were 0.07 and 0.11 µg Se/g respectively. Foods prepared from grains grown in Ontario (C) contained less Se than those from grains of the prairie provinces (W). Average values (µg Se/g) were: oat 0.15C, 0.45W; wheat 0.08C, 0.56W, 1.27 durum variety; bran preparations 0.07C, 0.87W. Average analyses of breads were: white 0.54 µg Se/g, brown 0.67, biscuits and pretzels 0.24. Se in spaghettis, macaroni and noodles varied from 0.65 - 1.42 µg Se/g. Values for vegetables varied from 0.001 to 0.138 µg Se/g and most fruits contained 0.01 µg Se/g or less. Meats varied in Se content from 0.03 µg/g in muscle to 2.70 in organs, and from 0.14 in egg white to 0.85 in yolk. Of the milk products analyzed, butter and cream had the least amount of Se, less than 0.01 µg/g and cheddar cheese the most, ca 0.12. Baby food preparations varied in Se content in a manner similar to that of adult foods.

Journal ArticleDOI
TL;DR: In this article, the relative stabilities of boehmite and beohmite in soils were examined in terms of experimental and thermodynamic evidence and it was shown that all three possible divariant assemblages of two phases that can exist between gibbsite, beahmite and H2O, may do so at 25°C and 1 atmosphere total pressure depending on the status of h2O.
Abstract: Two mutually exclusive views exist concerning the relative stabilities of gibbsite and boehmite in soils. These are examined in terms of experimental and thermodynamic evidence and it is shown that all three possible divariant assemblages of two phases that can exist between gibbsite, beohmite and H2O, may do so at 25°C and 1 atmosphere total pressure depending on the status of H2O. It is further shown that the conditions of H2O chemical potential needed to stabilize boehmite + H2O relative to gibbsite + H2O or gibbsite + boehmite, are unlikely to occur in natural waters in the zone of weathering.

Journal ArticleDOI
TL;DR: Abscisic acid, which inhibits stomatal opening, prevents the influx of K + ions into the guard cells in epidermal strips from leaves of Vicia jaba as discussed by the authors.

Journal ArticleDOI
TL;DR: In this paper, two major types of objective measurements were performed on raw porcine psoas muscle (I - shearing and breaking strength tests; II - sarcomere length, elasticity, stress relaxation and break elongation) and compared with taste panel evaluation (tenderness and chew count) of cooked meat.
Abstract: Two major types of objective measurements were performed on raw porcine psoas muscle (I - shearing and breaking strength tests; II - sarcomere length, elasticity, stress relaxation and break elongation) and compared with taste panel evaluation (tenderness, elasticity, and chew count) of cooked meat. A standard sample of texturized vegetable protein used as a reference by the panel proved useful in reducing variations between the chew count test and the objective evaluation; it was not of significant value with the other sensory evaluations. No significant correlations were found between the two groups of objective measurements. Breaking strengths of small longitudinal strips of tissue, following a brief cyclic or extension stretching on the Instron, were the best predictors of sensory tenderness accounting for 59–90% of variation. Other measurements also gave significant correlations. The major source of variation in breaking strength values was the variation between animals, but the post-mortem treatment (restraining versus not restraining during rigor) and the interaction between animals and the post-mortem treatment also were significant in some cases. Breaking strengths of uncooked samples from the same muscle showed a coefficient of variation of up to 54%. It is concluded that there are two major structural contributions of raw muscle to cooked meat tenderness, a connective tissue factor and a contraction factor; different objective methods are best suited for their evaluation.

Journal ArticleDOI
TL;DR: Emulsions of crude oil are lethal to larvae of the American Iobster at concentrations of 100 ppm and appear to have sublethal effects at concentrations down to 1 ppm.

Journal ArticleDOI
24 Mar 1972-Nature
TL;DR: A virus survey is conducted to determine the possible presence of IPN virus in fishes in the tailwaters of two IPN-infected trout hatcheries.
Abstract: INFECTIOUS pancreatic necrosis (IPN) is an acute, highly contagious viral disease of salmonid fishes. The disease is characterized by explosive outbreaks of mortalities in salmonid fry. Epizootics in hatchery fishes are dreaded, and have characterized it as a major disease of hatchery salmonids. Although the occurrence of the disease has been well documented in hatchery salmonids, little is known of its occurrence and consequences in native fishes. We conducted a virus survey to determine the possible presence of IPN virus in fishes in the tailwaters of two IPN-infected trout hatcheries.

Journal ArticleDOI
TL;DR: Normal female Ss were tested for the discrimination of paired flashes in the mornings and evenings of 3 days during the menstrual cycle, under both resting and activation conditions, and the threshold for fusion was highest at the premenstrual point and in the evening.
Abstract: Normal female Ss were tested for the discrimination of paired flashes in the mornings and evenings of 3 days during the menstrual cycle, under both resting and activation conditions. The threshold for fusion was highest at the premenstrual point and in the evening. A signal detection analysis indicated that the threshold change was the result of a change in criterion placement and not a change in sensory sensitivity as required by a biological clock hypothesis. No interactions were apparent for the three arousal variables.

Journal ArticleDOI
TL;DR: In this article, the efficiency curves measured for Si(Li and Ge(Li) X-ray detectors by the X/γ technique are presented and discussed, and the situation as regards efficiency calibration is reviewed and further work suggested.

Patent
25 May 1972
TL;DR: In this paper, the bacterial cells are treated with dilute formalin solutions (about 0.02 to about 0.08% v/v formalin) for a period to modify the bacteria without inactivation thereof.
Abstract: Preparation of and live bacterial vaccine from selected strains of Escherichia coli. The bacterial cells are treated with dilute formalin solutions (about 0.02 to about 0.08% v/v formalin) for a period to modify the bacteria without inactivation thereof. One preferred strain is EW1 serogroup of 0157. The vaccine has been found particularly effective in preventing the occurrence of enteric colibacillosis in newborn animals. A preferred technique is to vaccinate cows, recover the milk, and continually feed it as a milk replacer to the newborn during the susceptible period.

Journal ArticleDOI
16 Aug 1972-Nature
TL;DR: Under these conditions, induction is shown to be reversibly controlled by red and far red light, an effect ascribable to the pigment phytochrome.
Abstract: THE extractable activity of nitrate reductase from higher plant leaves is inducible by light and shows, under natural growth conditions, a pattern of diurnal variation1. Studies on the nature of light involvement have generally used the green leaf as experimental material, implying that photosynthesis supports the induction process1,2. We have examined the role of light for the induction of nitrate reductase activity in the etiolated terminal buds of field peas (Pisum arvense cv. Century). Treatments consisted of brief exposure of intact plants to broad bands of light, followed by a period in darkness before extraction for enzyme assay. These light treatments exclude the possibility of photosynthesis as a process contributing to induction. Under these conditions, induction is shown to be reversibly controlled by red and far red light, an effect ascribable to the pigment phytochrome.


Journal ArticleDOI
J.C. Roff1
TL;DR: Eier, die im Winter 1969 im Meretta-Lake abgelegt wurden, waren bis Juli 1970 nicht geschlupft (wahrscheinlich wegen des niedrigen Sauerstoffgehalts am Seegrund) and auch nach Einbringung in mit SauerStoff angereichertes Wasser im Labor nicht schlupften, konnen sie n
Abstract: [Die Fortpflanzungsbiologie von Limnocalanus macrurus wurde an Exemplaren aus arktischen Seen und dem Ontario See untersucht. Paarung und Ei-Ablage sowie das Ei werden beschrieben. Unter Laboratoriumsbedingungen nimmt die Inkubationszeit von 26 Tagen bei 0°C auf 17 Tage bei 10°C ab. Bei 16°C jedoch betragt die Eientwicklungsdauer 40 Tage, und die Sterblichkeitsrate wahrend der Eientwicklung, oder unmittelbar darauf, erreicht 100%. Auf Grund von Planktonuntersuchungen im Char-Lake wurde die Eientwicklungsdauer bei 0.5°C auf etwa 30 Tage geschatzt. Wenn man davon ausgeht, dass das Plankton in Abstanden von 5 bis 10 Tagen gesammelt wurde, so stimmt diese Schatzung sehr gut mit den Ergebnissen der Laboruntersuchungen (26 Tage) uberein. Eier, die im Winter 1969 im Meretta-Lake abgelegt wurden, waren bis Juli 1970 nicht geschlupft (wahrscheinlich wegen des niedrigen Sauerstoffgehalts am Seegrund) und auch nach Einbringung in mit Sauerstoff angereichertes Wasser im Labor nicht schlupften, konnen sie nicht als resistente oder ruhende Eier angesehen werden; es liegt der Schluss nahe, dass es sich hier um Subitaneier handelt., Die Fortpflanzungsbiologie von Limnocalanus macrurus wurde an Exemplaren aus arktischen Seen und dem Ontario See untersucht. Paarung und Ei-Ablage sowie das Ei werden beschrieben. Unter Laboratoriumsbedingungen nimmt die Inkubationszeit von 26 Tagen bei 0°C auf 17 Tage bei 10°C ab. Bei 16°C jedoch betragt die Eientwicklungsdauer 40 Tage, und die Sterblichkeitsrate wahrend der Eientwicklung, oder unmittelbar darauf, erreicht 100%. Auf Grund von Planktonuntersuchungen im Char-Lake wurde die Eientwicklungsdauer bei 0.5°C auf etwa 30 Tage geschatzt. Wenn man davon ausgeht, dass das Plankton in Abstanden von 5 bis 10 Tagen gesammelt wurde, so stimmt diese Schatzung sehr gut mit den Ergebnissen der Laboruntersuchungen (26 Tage) uberein. Eier, die im Winter 1969 im Meretta-Lake abgelegt wurden, waren bis Juli 1970 nicht geschlupft (wahrscheinlich wegen des niedrigen Sauerstoffgehalts am Seegrund) und auch nach Einbringung in mit Sauerstoff angereichertes Wasser im Labor nicht schlupften, konnen sie nicht als resistente oder ruhende Eier angesehen werden; es liegt der Schluss nahe, dass es sich hier um Subitaneier handelt.]



Journal ArticleDOI
TL;DR: These mycetomes in Helochara communis are anomalous, apparently lacking DNA, and probably being derivatives of t -symbiotes, thus requiring that Muller9s hypothesis of homopteran evolutionary pathways be rephrased.
Abstract: Mycetomes in Helochara communis are paired syncytia each enclosed by an epithelium. Adjacent are loose aggregates of mycetocytes. Mycetomes harboured 3 kinds of inclusions:companion, a - and t -symbiotes according to Buchner9s classification of homopteran symbiotes. In the mycetocytes, a fourth kind of inclusion was found and named g -symbiotes. All inclusions were Feulgen and Gram negative. Nucleoids were revealed in companion symbiotes by osmium-HCL-Giemsa; and, in some g - and t -, but not in a -, symbiotes by RNase-papain Giemsa. DNase digestion caused loss of basophilia in g - and t -, but not in a -, symbiotes. By electron microscopy, using Kellenberger9s fixative, companion, g - and t - symbiotes had lucid areas with reticular strands 4 nm thick; a -symbiotes were in general, homogeneously densely granular. Companion symbiotes had Gram-negative profiles with additional surface material; a - and t -symbiotes had 3, g -symbiotes 2, peripheral, trilaminar membranes. Parallel striations and regularly arranged granules occurred in companion symbiotes; crystalline inclusions in g - and t - symbiotes; and fibrillar elements and dense bodies in a -symbiotes. Companion symbiotes may be Gram-negative bacteria or rickettsiae; g - and t -symbiotes, L-phase bacteria; but a -symbiotes are anomalous, apparently lacking DNA, and probably being derivatives of t -symbiotes, thus requiring that Muller9s hypothesis of homopteran evolutionary pathways be rephrased.

Journal ArticleDOI
TL;DR: In this article, the authors analyze the process of conversion to A and its various phases, with special emphasis on the ways A.A. helps alcoholics to come to terms with their &dquo;sordid pasts, and that is, with discontinuity and guilt.
Abstract: no longer felt any guilt. Lofland points to two major problems which individuals undergoing the profound change demanded by conversion often face: the problems of discontinuity (the loss of the old identity and meaning system) and guilt.4 In this paper we shall analyze the process of conversion to A.A. and its various phases, with special emphasis on the ways A.A. helps alcoholics to come to terms with their &dquo;sordid pasts,&dquo; that is, with discontinuity and guilt. Our general perspective is derived from Goffman, particularly his essay &dquo;On Cooling Out the Mark,&dquo;5 and the writings of Berger (1963) and Berger and Luckman (1967) on the social construction of reality.

Journal ArticleDOI
TL;DR: In this article, the double layer effect in the electroreduction of ferricyanide anion in both water and forma-mide was investigated and attributed to a non-equilibrium distribution of the reactant in the double-layer and the participation of ion pairs in the reaction mechanism.

Journal ArticleDOI
TL;DR: Four rumen-fistulated Holstein cows were used in a Latin square design experiment over 20 weeks to compare effects of a standard diet, basal low-fat, basal + hydrogenated tallow, and basal + soybean oil diets on voluntary feed intake, rumen fermentation, and on yield and composition of milk.

Journal ArticleDOI
TL;DR: Calves sensitized by subcutaneous injection of horse serum in Freund's adjuvant induced increased blood kinin activity, and this kinin activation correlated with the protracted fall in systemic blood pressure seen in the same animals.
Abstract: Calves were sensitized by subcutaneous injection of horse serum in Freund's adjuvant. Subsequent challenge with intravenous horse serum induced increased blood kinin activity. This kinin activation correlated with the protracted fall in systemic blood pressure seen in the same animals.

Journal ArticleDOI
TL;DR: Consonant report was unaffected by carrying a spatial load and barely affected by carrying the auditory digit load, suggesting an auditory-verbal loop cannot play a mandatory role in the coding and storage of visual information.
Abstract: Subjects were required to report an array of consonants presented tachistoscopically for various durations. Concurrently, they held in memory a load of auditory digits, a load of spatial locations or no load. These several forms of information did not seem to compete for a fixed capacity short term store. Consonant report was unaffected by carrying a spatial load and barely affected by carrying the auditory digit load. An auditory-verbal loop cannot play a mandatory role in the coding and storage of visual information. Some criticisms of structural interpretations of immediate memory are suggested. Now at University of Guelph, Guelph, Ontario, Canada.