Showing papers by "University of Guelph published in 1970"
TL;DR: The first observations on interspecific crosses, followed by embryo culture, illustrating an equally promising method for obtaining haploids in barley and perhaps other species are reported.
Abstract: HAPLOIDS have been sought and investigated in many plant species since their first identification in Datura1. The chief limitation in using them to produce homozygous lines for plant breeding programmes or genetic research has been the lack of techniques by which large numbers of haploids can be obtained from any given stock2. Reports3,4 of haploid plants obtained from anther cultures offer a potential technique and here we report our first observations on interspecific crosses, followed by embryo culture, illustrating an equally promising method for obtaining haploids in barley and perhaps other species.
593 citations
TL;DR: In this paper, the effects of familiarity and changes in stimulus orientation on immediate and delayed recognition of human faces, canine faces, and buildings were examined. And it was concluded that increased familiarity improved recognition and the disproportionate difficulty for rotated human faces was independent of familiarity.
Abstract: The purpose of this study was to examine the effects of familiarity and changes in stimulus orientation on immediate and delayed recognition of human faces, canine faces, and buildings. Eighty Ss were assigned randomly to one of four experimental conditions: immediate or delayed recognition of stimuli presented and tested in the same orientation and immediate or delayed recognition of stimuli presented and tested in opposite orientations. Results indicated that familiar stimuli presented for seven successive inspection trials were significantly better recognized than were unfamiliar stimuli inspected only once. Recognition performance declined as a function of stimulus rotation and a 20-min delay in testing. This decline was significantly greater for human faces than for other stimuli, regardless of the recall interval used. It was concluded that increased familiarity improved recognition and that the disproportionate difficulty for rotated human faces was independent of familiarity.
149 citations
TL;DR: In this paper, a tranesterifying reagent used consists of 15% methanolic sodium methoxide solution 0.5 N, 60% petroleum ether and 25% diethyl ether which forms a one phase system at room temperature.
120 citations
TL;DR: Chromosome pairing takes two steps: members of the homologous pair become aligned first and then “zip up” throughout their length, followed by a diffuse stage in which the chromosomes are most indistinct.
Abstract: Chromosome pairing takes two steps: members of the homologous pair become aligned first and then “zip up” throughout their length. Initial contact may begin from one end or from both ends of the chromosomes. Prom late paehytene to diplotene, the chromosomes are somewhat elongated and exhibit lampbrush characteristics. This is followed by a diffuse stage in which the chromosomes are most indistinct. The centrosome divides at this time. The chromosome numbers are as follows: Coprinus lagopus, n=12; C. micaceus, n=12, C. comatus, n=14; and C. atramentarius, n=16.
120 citations
TL;DR: In this paper, the anniliation lineshape is used to measure the percentage of positrons trapped by dislocations, and the sample hardness is a linear function of the logarithm of the deformation.
118 citations
01 Jan 1970
TL;DR: In this paper, the authors examined the initial effects of the introduction of Universal Primary Education (UPE) in January 1997 on school entry in Uganda and found that the effect of UPE on the probability that a child begins attending school before age nine.
Abstract: This paper examines the initial effects of the introduction of Universal Primary Education (UPE) in January 1997 on school entry in Uganda. Given that advanced age at school entry has historically been associated with primary school dropout, the paper focuses on the the effects of fee elimination on the age at which a child enters school. Data from the 2000 Uganda Demographic and Health Survey and 2001 Education Data Survey are employed to examine the effects of UPE on the probability that a child begins attending school before age nine. School fee elimination under UPE is found to cause a 3% increase in this probability on average. Effects are found to be particularly pronounced for girls and children living in rural areas.
108 citations
TL;DR: In this paper, a cross-Canada survey of B5141-63 potatoes grown at 12 locations showed a distinct bitter off-flavour found to be due to the presence of unusually high total glycoalkaloid content (TGA), mostly in excess of 20 mg per 100 gm of fresh weight.
Abstract: A cross-Canada survey of B5141-63 potatoes grown at 12 locations showed a distinct bitter off-flavour found to be due to the presence of unusually high total glycoalkaloid content (TGA), mostly in excess of 20 mg per 100 gm of fresh weight. Samples of check varieties commonly grown in the selected locations, Kennebec, Irish Cobbler and Netted Gem, showed comparably low, normal TGA levels. As there is strong evidence that the high TGA levels in B5141-6 tubers are reached before detachment from the mother plant, it is assumed that the ability of B5141-6 to produce or accumulate such high levels is strongly inherited. To date, high TGA levels were found to be only due to the effects of post-harvest environment (6, 7). The implications of the TGA potential are discussed in relation to the existing potato improvement programmes and the need for a routine screening test for new introductions.
107 citations
TL;DR: In this article, sufficient statistics for the parameters a and v of the Pareto distribution are obtained using sufficiency and stochastic independence of Z and Y 1, and the exact distribution of the maximum likelihood estimator is derived.
Abstract: In this paper, sufficient statistics for the parameters a andv of thePareto distribution are obtained. Using sufficiency, it is shown that the statistic
$$Z = \mathop \sum \limits_{i = 1}^N \log \left( {{}^{Y_{i/} }Y_1 } \right)$$
is stochastically independent of the sufficient statisticY
1. Using sufficiency and stochastic independence ofZ andY
1, the exact distribution of the maximum likelihood estimator
$$\hat v$$
is derived.
100 citations
TL;DR: Pectic enzyme production and virulence were not closely correlated, although there was some suggestion with the hop isolates of V. albo-atrum that higher PME and PG production was associated with high virulence.
Abstract: Twenty-three isolates of Verticillium albo-atrum, sixteen of V. dahliae, two of V. tricorpus, four of V. nigrescens and one of V. nubilum, all produced endopoly-galacturonase (PG), pectin trans-eliminase (PTE) and pectin methylesterase (PME) in amounts that varied as much within species as between them. Maximal production of viscosity-reducing enzymes occurred after 7 days, with peaks of activity at approximately pH 5·0 and 9·0; the former was attributed to the action of endo-PG, and the latter coincided with the optimal pH of PTE. Production of PTE and PG was constitutive but was increased by the presence of pectin in the medium. PME was produced in a pectin-glucose-salts medium but not in a potato extract-pectin medium. Pectic enzyme production and virulence were not closely correlated, although there was some suggestion with the hop isolates of V. albo-atrum that higher PME and PG production was associated with high virulence. When isolates of V. albo-atrum or V. dahliae, grown on pectin-glucose-salts medium, were ranked according to PG or PME activity they tended to fall into groups having in common the species, variety or locality of the host from which they were isolated.
80 citations
TL;DR: Incubation of DNA-loaded filters in a solution of 50% formamide containing 6x standard saline citrate, at 48 C for 40 hr, was judged to be the best set of conditions tested based on relatively good retention of immobilized DNA, very low hybridization with unrelated DNA of a similarly high T(m) (from Sarcina lutea), and the formation of complexes similar in thermal stability to the native DNA.
Abstract: Variations of the membrane filter technique for deoxyribonucleic acid (DNA) hybridizations were studied with respect to Streptomyces species At the temperatures required for specific hybridization of DNA with the high melting temperature (Tm) characteristic of Streptomyces, large amounts (up to 97%) of filter-bound DNA became eluted, in all reaction mixtures studied, within 21 hr In most solutions this leaching was increased by the presence of sheared denatured DNA Incubation of DNA-loaded filters in a solution of 50% formamide containing 6× standard saline citrate, at 48 C for 40 hr, was judged to be the best set of conditions tested based on relatively good retention of immobilized DNA, very low hybridization with unrelated DNA of a similarly high Tm (from Sarcina lutea), and the formation of complexes similar in thermal stability to the native DNA The expression of results as sheared DNA bound in relation to long-chain DNA retained is recommended when a high concentration of sheared DNA relative to immobilized DNA is used
43 citations
TL;DR: An investigation into the Healing of experimentally produced fractures of the radius and ulna of miniature poodles is reported and a comparison is made between the healing of fractures subjected to various postoperative regimes.
Abstract: An investigation into the healing of experimentally produced fractures of the radius and ulna of miniature poodles is reported.
A comparison is made between the healing of fractures subjected to various postoperative regimes.
Resume. Etude de la consolidation des fractures experimentales du radius et du cubitus chez les caniches nains. Comparaison des resultats de differentes methodes de traitement post-operatoire.
Zusammenfassung. Es wird uber eine Untersuchung der Heilung experimentell verursachter Frakturen des Radius und der Ulna von Zwergpudeln berichtet.
Zwischen den Heilungserfolgen bei den Frakturen nach verschiedenen postoperativen Behandlungsweisen werden Vergleiche angestellt.
TL;DR: In this paper, a sociological framework for the study of any social phenomenon is presented, where the main concern is with the collectivity dimensions of the phenomenon modified as appropriate and meaningful by its culture and personality systems dimensions.
Abstract: A general theorectical orientation is missing in most studies of migration. Although there have been efforts in this direction a sociological theory of migration which meets the stringent demands of formal theory is not likely to materialize in the ner future. For purposes of this discussion migration is conceived of as a phenomenon having some aspects located within the culture system some within the social system and some within the personality system sectors of human social organization. The main concern is with the collectivity dimensions of the phenomenon modified as appropriate and meaningful by its culture and personality systems dimensions. In developing a sociological framework for the study of any social phenomenon attention must be on a number of tasks: 1) that part of the phenomenon which is socially relevant must be abstracted from the totality of its dimensions; 2) a sociological frame of reference for the study of society must then be outlined and the phenomenon of interest located within that framework; and 3) in order to test the utility of this approach crucial questions derviced from the proposed theoretical treatment should be indicated and examined as to their researchability and their potential contribution. This is the procedure followed in this discussion. Following a discussion of the sociological dimensions of migration - permanent moving away and changes in the interactional system - the attempt is made to demonstrate the usefulness of the presented approach by pointing out how sociologically relevant quesitons concerning migraiton can be considered within the context of this approach.
TL;DR: In this article, Tiku's (1965) approximation to the distribution of a non-central F, say F', based on the central F or variance ratio distribution, is investigated, by examining the relations between the moment ratios,81 and t32 for F and F', and it is shown why the approximation proved successful.
Abstract: SUMMARY The investigation starts from Tiku's (1965) approximation to the distribution of a non-central F, say F', based on the central F or variance ratio distribution. By examining the relations between the moment ratios ,81 and t32 for F and F', it is shown why the approximation proved successful.
TL;DR: A simplified gas-liquid chromatographic technique for the separation and quantification of the major aromatic aldehydes and acids produced by the alkaline nitrobenzene oxidation of lignin has been described in this article.
TL;DR: In this paper, the authors developed a large pool of items to measure the dimension of Evaluation Sensitivity, and to appraise the degree to which this item pool would shorn adequate psychometric properties.
Abstract: THE area of personality assessment has experienced very substantial advances during the past decade, both in terms of its conceptual development, and in terms of its increased use of measurement techniques. Nowhere have these changes become more apparent than in the area of personality test development, where a modern 'methodology has replaced the simplistic conceptions of an earlier day. Ad hoc procedures, like empirical item selection against external criteria, have been found inadequate as a means for approaching the measurement of personality traits as constructs (Loevinger, 1957). Increasingly, there has developed an appreciation of the value of sequential strategies for item selection in personality assessment. Multiple strategies for item selection have been required by virtue of the simultaneous demands for item representativeness and scale generalizability, substantive cogency, homogeneity, and freedom from response biases, as well as for convergent and discriminant validity. One important purpose of the present investigation was to develop a large pool of items to measure the dimension of Evaluation Sensitivity, and to appraise the degree to which this item pool. would shorn adequate psychometric properties. The theoretical,
TL;DR: The dichotomy of the natural environment of amphibious mammals presents special optical problems if a well focused, faithful representation of their world in both media is to appear on the retina.
Abstract: THE dichotomy of the natural environment of amphibious mammals presents special optical problems if a well focused, faithful representation of their world in both media is to appear on the retina. When the cornea of a vertebrate eye is in contact with water, the overall refractive power of the eye is somewhat lessened because of the similarity of the refractive indices of water and the cornea.
TL;DR: The plasticity of the species to adapt to a variety of ecological conditions and the species potential for high production favour its introduction to waters requiring a good converter in the food chain.
Abstract: The study of the emerald shiner Notropis atherinoides Rafinesque was conducted in 1967 and 1968 in Lake Simcoe, a eutrophic inland lake with an area of 725 km2 situated in the Province of Ontario, Canada. On the basis of meristic characters, the emerald shiner of Lake Simcoe conforms to the classical description of the species and is not distinct from the form inhabiting the Great Lakes. Annulus formation occurred in early June on age I fish but second and third annuli were not formed on older fish until late July through August.Young-of-the-year emerald shiners reached a total length of 45 mm by October; age I were 81 mm and age II measured 92 mm by the same month. By September, age I female emerald shiners attained a size superiority of 5 mm over males of that age group and by the end of the third summer age II females exceeded age II males by 8 mm. Spawning occurred offshore in the latter part of July when surface water temperatures approximated 20°C. Of the three age groups, age II specimens were the most prevalent on the spawning grounds. Average absolute fecundity was 3410 eggs in fish of all age classes combined. Differences in water temperature seem to strongly influence the seasonal distribution pattern of the emerald shiner. The final temperature preferendum of the species, as determined in a vertical temperature gradient tank, was 25°C. The emerald shiner is extensively utilized as a bait fish by anglers and appears to be an important forage fish. The plasticity of the species to adapt to a variety of ecological conditions and the species potential for high production favour its introduction to waters requiring a good converter in the food chain.
TL;DR: To investigate the degree of variation which might be encountered with the multitude of commercial crosses yet avoid actual experimentation with each, Moran et al. (1970) determined the differences which existed between two of the most commonly used broiler breeds and their reciprocal crosses.
TL;DR: It is concluded that recombination is an event subsequent to the formation of the S.C. and is independent of the process of its formation and is suggested that the event takes place at the synaptic centre.
Abstract: The frequency of genetic recombination in Coprinus lagopus may be modified by heat and cold shock. By removal of samples from a fruiting body before and after temperature treatment, it is possible to study the ultrastructure of chromosomes at the time recombination frequency (between den + x + me -1) can be modified. The sensitive period for temperature effects and, therefore, probably the time of crossing over, commences with the formation of the synaptinemal complex (S.C.) and ends with its disappearance, i.e. during the entire existence of the S.C. It is concluded that recombination is an event subsequent to the formation of the S.C. and is independent of the process of its formation. It is suggested that the event takes place at the synaptic centre.
TL;DR: Viomycin resistance in a mutant of Rhizobium meliloti was found to involve an accumulation of phospholipid in the cell envelope, and 14C-labelling revealed that this accumulation occurred at the expense: of neutral lipids in the envelope.
TL;DR: In this paper, a spatio-temporal equilibrium model that incorporates intraseasonal demands for irrigation water is developed for the situation with a (constrained) competitive market for water.
Abstract: A spatio-temporal equilibrium model that incorporates intraseasonal demands for irrigation water is developed for the situation with a (constrained) competitive market for water. An application of the quadratic programming model, which utilizes demand and supply estimates relating to an intensive irrigation area in southeastern Australia, is used to derive optimal short-run allocation and pricing patterns for the resource. Extensions of the model to cover multiple dam river basins and additional water uses seem conceptually straightforward, but the limitations imposed by its deterministic partial equilibrium character should be recognized.
TL;DR: The immediate effects on blood composition were mainly caused by aspirated water, whereas later effects probably were considerably influenced by swallowed water, and whether blood composition continues to change after cardiac arrest is investigated.
Abstract: Experiments involving lethal and nonlethal drowning were performed in rats and dogs to investigate the effects of aspirated and swallowed water on blood composition, scrum potassium increase owing to hemolysis, damage to pulmonary tissue, and whether blood composition continues to change after cardiac arrest The ratios between aspirated and swallowed water amounted to 1:1 in fresh-water and 1:3 In sea-water drowning. The immediate effects on blood composition were mainly caused by aspirated water, whereas later effects probably were considerably influenced by swallowed water. A maximum of 33 per cent of the potassium increase in lethal drowning was due to hemolysis. Sea water produced more damage to pulmonary tissue than fresh water. After cardiac arrest, blood composition did not continue to change for at least three minutes.
TL;DR: In the Cratylus, the main distinguishing feature is its plurality, as opposed to the unity characteristic of the "classical Form" as mentioned in this paper, which is a characteristic of Heracliteanism.
Abstract: In this paper I want to consider two passages of the Cratylus in some detail (389 a 390 e, and 439 c 440 d). Despite their familiarity to students of Plato, it is my belief that commentators have overlooked certain subtle but important distinctions that are to be discerned in them, distinctions which, if sound, modify the usual interpretations of the dialogue. Briefly, what I hope to show is that in the first passage we are introduced to a different kind of non-sensible entity, akin to the Form, but whose main distinguishing feature is its plurality, as opposed to the unity characteristic of the "classical Form". In the second, a short discussion of Heracliteanism, it seems to me that Plato's analysis of the doctrine of flux is far more intricate and complicated than is generally allowed.
TL;DR: In this article, a yaw sphere has been designed that measures a quantity proportional to the vertical heat flux, and some comparisons are given with measurements made with a three-dimensional pressure-sphere anemometer, in combination with a fast-response thermometer.
Abstract: A yaw sphere has been designed that measures a quantity that is proportional to the vertical heat flux. The method is described, and some comparisons are given with measurements made with a three-dimensional pressure-sphere anemometer, in combination with a fast-response thermometer.
TL;DR: The gross and histological lesions produced in the colon and caecum of each pig are described and Necrotic enteritis occurred in the pigs infected with the largest numbers of infective larvae.
TL;DR: Direct and correlated responses to selection for 12-week body weight, together with time trends in heritability estimates were also studied in strains derived from the base populations of turkeys.
TL;DR: If oviposition occurs at a time approximating the average then shell formation per se will not commence until after 4 p.m. that afternoon, and if the sole source of calcium is from the diet then less than half of the 20 or so hours used in shell building is available for direct use of the consumed calcium.