Showing papers by "Laval University published in 1983"
TL;DR: In this paper, the growth of twenty plant species was compared under field conditions in a methyl bromide fumigated and non-fumigated soil, and three groups of plants were distinguishable based on plant growth responses.
Abstract: The growth of twenty plant species was compared under field conditions in a methyl bromide fumigated and non-fumigated soil. The non-fumigated soil had a wild endomycorrhizal flora and contained 100 μg/g of available phosphorus. No phosphorus was added to the soil but both fumigated and non-fumigated plots received a basal fertilization of 100 kg/ha N−NH4NO3 and 100 kg/ha K−KCl. Based on plant growth responses, three groups of plants were distinguishable. Plants from group I were mycorrhizal and had better growth in non-fumigated than in the fumigated soil. This group was the most important, including sixteen plant species. Stunting of plants from group I following soil fumigation was mainly attribuable to the destruction of mycorrhizae. Plants from group II (oat and wheat) grew equally well in non-fumigated and fumigated soils. For these plants which were mycorrhizal in the non-fumigated plots, the P-content of the soil was sufficient for growth and therefore no stunting was observed in the absence of mycorrhizae. Plants from group III (cabbage and garden beet) grew better in fumigated than in non-fumigated soil. Their better growth in fumigated soil was tentatively attributed to the destruction of soil-borne pathogens. They did not form mycorrhizae in non-fumigated soil.
548 citations
TL;DR: The present data show that complete withdrawal of androgens by combined hormonal therapy with the LHRH agonist (or castration) and a pure antiandrogen leads to a positive objective response in more than 95% of cases as opposed to 60%‐70% as reported by many groups using the previous partial hormonal therapy.
Abstract: To completely eliminate androgens of both testicular and adrenal origin, 37 previously untreated patients with advanced (stages C or D) prostatic cancer received the combination therapy using an LHRH agonist (HOE-766) and a pure antiandrogen (RU-23908). The response criteria developed by the National Prostatic Cancer Project were used. A positive response (assessed by bone scan and/or serum prostatic acid phosphatase measured by radioimunoassay was observed in 29 of the 30 cases who could be evaluated by these objective criteria (97%). The objective response was parallel to a rapid and marked improvement of the clinical signs and symptoms related to prostate cancer (prostatism, bone pain, and general well being). In marked contrast, the same combination therapy applied to patients previously treated with high doses of diethylstilbestrol (13 patients) showed a positive objective response in only 55% of cases. In 23 previously castrated patients showing relapse, an objective response was seen in only 25% of cases after neutralization of adrenal androgens by the antiandrogen. Previous treatment with chlorotrianisene (TACE) had no detectable effect on prostatic cancer and patients having previously received such treatment had a rate of positive response similar to previously untreated patients (five of five). In the previously untreated patients receiving the combination therapy, a 60% fall in serum prostatic acid phosphatase was observed as early as five days after starting treatment, at a time when the serum androgen concentration was 100% to 200% above control. Combined treatment with the pure antiandrogen completely prevents flare-up of the disease, a complication previously found in a significant proportion of patients treated with an LHRH agonist alone. The present data show that complete withdrawal of androgens by combined hormonal therapy with the LHRH agonist (or castration) and a pure antiandrogen leads to a positive objective response in more than 95% of cases as opposed to 60%-70% as reported by many groups using the previous partial hormonal therapy (castration or high doses of estrogens). Adrenal androgens are most likely responsible for this difference. The present study also shows that the proportion of androgen-sensitive cells decreases from more than 95% in untreated patients to 25% to 55% after previous partial hormonal therapy. Such data clearly indicate that the previous partial hormonal therapy exclusively aimed at neutralizing testicular androgens left 25% to 55% of cancer cells having a relatively low sensitivity to adrogens in a hormonal milieu compatible with their continuous growth. No clinical or biochemical side effect could be detected except those related to reduced serum androgen levels. Due to the ease of its application and the lack of secondary effects other than those related to hypoandrogenicity, the present data clearly suggest that complete (instead of partial) androgen withdrawal should be performed as early as possible after diagnosis, at least in advanced prostatic cancer, to reduce the development of androgen-insensitive cell clones and to facilitate the adjuvant treatment with chemotherapeutic agents and/or radiotherapy of androgen-insensitive tumors in the appropriate cases.
289 citations
TL;DR: This paper is an attempt to put model validation and related issues in a framework that may be of use both to model-builders and to decision-makers.
252 citations
TL;DR: An increase in the level of intracellular free calcium concentration in rabbit and human neutrophils stimulated by chemotactic factors has been demonstrated directly using the calcium-sensitive fluorescent probe quin-2.
185 citations
183 citations
TL;DR: It is shown in this paper that non-conforming finite elements on the triangle using second-degree polynomials can be easily built and used and that this element exhibits a very peculiar regularity property.
Abstract: It is shown in this paper that non-conforming finite elements on the triangle using second-degree polynomials can be easily built and used. Indeed they appear as an ‘enriched’ version of the standard piecewise quadratic six-node element. This work is divided into two parts. In the first we present the basic properties of the element, namely how it can be built and basic error estimates. We also show that this element exhibits a very peculiar regularity property. In the second part we apply our element to the approximation of viscous incompressible flows and more generally to the approximation of incompressible materials.
174 citations
TL;DR: It is concluded that the serum-ascites albumin gradient offers the best diagnostic discrimination between ascite caused by liver disease and ascites caused by a neoplasm.
158 citations
TL;DR: It is suggested that a 3-day dietary record provides reliable estimates of the intake of almost all nutrients, particularly in children.
157 citations
TL;DR: In this article, the osmotic dehydration of apples using a circulation system is described in terms of mass transfer concepts, where the parameters investigated were the loss of water and the gain of sugar.
Abstract: The osmotic dehydration of apples using a circulation system is described in terms of mass transfer concepts, where the parameters investigated were the loss of water and the gain of sugar. It was found that the loss of water was influenced by the temperature and the °Brix of the osmotic agent. The sugar gain reached a maximum after 30 min dehydration time and remained constant for the rest of the processing time. A mathematical model for this phenomena was proposed and it was found to correlate highly with the experimental data. The apparent diffusion coefficient D was evaluated and multilinear analysis revealed that D depended on temperature and °Brix in addition to a combined effect of both parameters.
138 citations
TL;DR: In the experimental area a sharp increase in the growth rate of a cohort of very small urchins, which was not eliminated by the removal effort, demonstrated that there is strong intraspecific competition amongst urchin competition when the food supply is limited.
Abstract: The role of sea urchins, Strongylocentrotus droebachiensis, in structuring the rocky subtidal community was examined at Anse aux Basques on the north shore of the St. Lawrence Estuary, Quebec. In an experimental area, measuring 20x20 m and extending from 0 to 10 m in depth, we greatly reduced the intensity of urchin grazing by eliminating all urchins larger than 10 mm in test diameter. This area was observed for two years and compared to an adjacent control area. In the upper portion of the experimental area during the first month after urchin removal, mid-July to mid-August 1978, a dense diatom cover developed, and during the second month the diatoms were overgrown by Ulvaria obscura. After four months (November) an Alaria esculenta overstory was present from near low water level to 3 m deep. Community development was much slower at greater depths and it took a year for the Alaria zone to extend to 4–5 m deep, and two years to extend to 6 m deep. The low light penetration at this estuarine location was probably the main factor for the slow algal development at 6–10 m deep. At the end of the experiment Agarum cribrosum was second in importance after Alaria and was most common at 3 to 6 m in depth. Laminaria spp. was found in low numbers in the first year and did not show an increase during the second year. There was a dramatic increase in the number of species and abundance of algae in the experimental area. Also, there was a marked increase in many animal species, particularly Acmaea testudinalis, Mytilus edulis and Margarites helicinus, and a decrease in Metridium senile. By contrast, in the control area, the number of algal and invertebrate species remained low. In the experimental area a sharp increase in the growth rate of a cohort of very small urchins, which was not eliminated by our removal effort, demonstrated that there is strong intraspecific competition amongst urchins when the food supply is limited. In the St. Lawrence Estuary, there are few predators of urchins and the urchin dominated community appears to be a stable situation.
133 citations
TL;DR: Findings could signify either that the binocular region contains additional interneurons specifically related to binocular interactions or that it has a greater number of neurons projecting to other cortical and subcortical areas, or both.
Abstract: The number of neurons in individual laminae of area 17 was determined separately for both the binocular and the monocular, regions in the left hemi-sphere of six cats. The number of neurons/mm3 of tissue was obtained for each lamina by using the method of size-frequency distribution applied to neuronal nuclei. The number of neurons per unit of cortical surface could then be calculated from measurements of layer, thickness. The number of neurons/mm3 of tissue for trie total cortical thickness is on the order of 48,000 to 50,000 neurons, with no statistically significant differences be-tween binocular and monocular regions. There are no significant differences for any of the layers except layer IV, in which the numerical density is 20% higher in the monocular region. The thickness of the cortex and of many of its layers, however, do vary between the two regions. Consequently there are significant differences in the number of neurons under 1 mm2 the total cortical thickness there are significantly more (27%) neurons in the binocular (78,440) than in the monocular region (61,900). This overall difference is due to significant changes in layers II, IIIA, IVA, and especially in layers V and VIA where neurons are 40% more numerous in the binocular region. These findings could signify either that the binocular region contains additional interneurons specifically related to binocular interactions or that it has a greater number of neurons projecting to other cortical and subcortical areas, or both.
TL;DR: In this paper, a double multiple stream tube (DMS) model was used for predicting the aerodynamic loads and performance of the Darrieus vertical-axis turbine, and a semi-empirical dynamic-stall model has been incorporated and a better approximation was obtained for modeling the local aerodynamic forces and performance.
Abstract: The objective of the present paper is to show the new capabilities of the double multiple streamtube (DMS) model for predicting the aerodynamic loads and performance of the Darrieus vertical-axis turbine. The original DMS model has been improved (DMSV model) by considering the variation in the upwind and downwind induced velocities as a function of the azimuthal angle for each streamtube. A comparison is made of the rotor performance for several blade geometries (parabola, catenary, troposkien, and Sandia shape). A new formulation is given for an approximate troposkien shape by considering the effect of the gravitational field. The effects of three NACA symmetrical profiles, 0012, 0015 and 0018, on the aerodynamic performance of the turbine are shown. Finally, a semiempirical dynamic-stall model has been incorporated and a better approximation obtained for modeling the local aerodynamic forces and performance for a Darrieus rotor.
TL;DR: The results for 34 college students confirmed previous data showing high performance in identification of all emotions, although there were some important differences between emotions.
Abstract: The aim of the experiment was to study the relation between accuracy of judgment of facial expressions of emotions and time for judgment The results for 34 college students confirmed previous data showing high performance in identification of all emotions, although there were some important differences between emotions Also, times for judgment were longer for the emotions which were more difficult to identify
TL;DR: The findings reveal that the SNr neurons in primate, as those in rat and cat, display a high degree of axonal branching and the output organization of SNr appears to differ markedly from that of the substantia nigra pars compacta, but is remarkably similar to the internal pallidum which is the other major output structure of the basal ganglia.
TL;DR: It appeared that the degree of atrophy was not related closely to changes in the IEMG suggesting that limb immobilization was not necessarily a model of “disuse”.
TL;DR: Rats were trained to feed each day from 10 o'clock to 12 noon and the preference was: shortcake, Coca-cola, meat pâté, peanut butter, and chow, there was a considerable variation between rats in their attraction to different foods.
TL;DR: It is recommended that a DCMU treatment be subtracted from the standard light carbon dioxide fixation for accurate estimation of phytoplankton production.
Abstract: Subtracting dark 14C fixation from light 14C fixation can lead to serious underestimates of phytoplankton production in aquatic environments. Light, temperature, and nutrient time-course experiments show that there is an active and an inactive incorporation component of 14C in the dark. The active incorporation can be prevented by adding DCMU (dissolved in water) to either a light or a dark bottle, thus estimating the inactive component. It is therefore recommended that a DCMU treatment be subtracted from the standard light carbon dioxide fixation for accurate estimation of phytoplankton production.
01 Jan 1983
TL;DR: Xylitol inhibited the growth of all but one of ten strains of S. mutans and failed to inhibit the grow of the lactobacilli, actinomycetes, and other streptococci tested except S. sanguis 10556, which was slightly inhibited.
Abstract: We investigated the effect of xylitol on the growth of different oral bacteria in the presence of glucose. Xylitol inhibited the growth of all but one of ten strains of S. mutans and failed to inhibit the growth of the lactobacilli, actinomycetes, and other streptococci tested except S. sanguis 10556, which was slightly inhibited. However, the rate of acid production of the sensitive S. mutans strains was not equally affected by xylitol. These data, obtained with pure cultures of acidogenic oral bacteria, may explain the lack of an in vitro inhibitory effect of xylitol on dental plaque samples.
TL;DR: The simple Bouguer gravity anomaly field of continental Ecuador corresponds closely to the physiographic provinces of the country as mentioned in this paper, including the Andes and their foothills, which is characterized by a pronounced low with values to −292 mgal, which reflects the deep Andean root.
Abstract: The simple Bouguer gravity anomaly field of continental Ecuador corresponds closely to the physiographic provinces of the country. The Sierra, which includes the Andes and their foothills, is characterized by a pronounced low with values to −292 mgal, which reflects the deep Andean root. Bouguer anomalies over the Oriente become less negative away from the Sierra, chiefly in response to progressive thinning of continental crust eastward. The Costa, between the Sierra and the Pacific shore, in the north has the most positive on-land Bouguer anomalies (+162 mgal) so far known in the Western Hemisphere. This part of the Costa is underlain by an ancient oceanic plate now welded to the northwestern corner of the otherwise continental South American plate.
TL;DR: Osmium tetroxide was used to sterilize the surface of roots of Vaccinium angustifolium and V. corymbosum in order to isolate mycorrhizal fungi and three isolates of sterile mycelium, all of similar cultural appearance, were obtained and proved capable of forming ericoid my Corrhizas under aseptic conditions.
Abstract: SUMMARY
Osmium tetroxide was used to sterilize the surface of roots of Vaccinium angustifolium and V corymbosum in order to isolate mycorrhizal fungi Three isolates of sterile mycelium, all of similar cultural appearance, were obtained from V angustifolium and were proved capable of forming ericoid mycorrhizas under aseptic conditions Three isolates were also obtained from V corymbosum and all formed conidiophores identified as Oidiodendron griseum Robak; they also formed ericoid mycorrhizas under aseptic conditions
TL;DR: The quaternARY ammonium compound as well as the quaternary ammonium-glutaraldehyde complex were more readily neutralized whereas anionic acid, iodophor and sodium hypochlorite did not tolerate the presence of organic matter.
Abstract: The effect of organic matter on the activity of eight disinfectants was evaluated. Three types of interfering substrates (whole milk powder, dried beef blood and fish meal) were tested according to the method of Whitmore and Miner adapted to the AOAC use-dilution method. Glutaraldehyde and to a certain extent, chlorhexidine acetate and the amphoteric surfactant kept their disinfecting activity after contact with high concentrations of organic matter. The quaternary ammonium compound as well as the quaternary ammonium-glutaraldehyde complex were more readily neutralized whereas anionic acid, iodophor and sodium hypochlorite did not tolerate the presence of organic matter. The neutralizing activity of powders was correlated to their solubility and composition.
TL;DR: In this article, a mixture of 507 sewage sludge and algae increases the methane yield and the productivity over twofold and showed a synergistic effect and spent sulfite liquor added at concentrations over 307 V/V has inhibited methanogenic activity.
Abstract: Mixtures of carbon-rich wastes andS. maxima algal biomass increase markedly the performance of anaerobic digestion. A mixture of 507 sewage sludge and algae increases the methane yield and the productivity over twofold. Peat hydrolyzate and sewage sludge, when added to algae, have shown a synergistic effect and spent sulfite liquor added at concentrations over 307 V/V has inhibited methanogenic activity.
TL;DR: There were no statistically significant differences in the various test scores between the two populations at age 12 months, but at age 18 and 36 months the hypothyroid infants had lower scores in hearing-speech performance scales and practical reasoning which also decreased their global quotient.
TL;DR: The present data show that the additive effect of epinephrine on CRF-induced ACTH release is achieved through an alpha-adrenergic receptor and is accompanied by a marked stimulation of intracellular cyclic AMP levels.
TL;DR: Results of the nonparametric tests used to compare the forecasts confirmed that technical expertise, judgmental adjustment, and individualized analyses were of little value in improving forecast accuracy as compared to black box approaches.
Abstract: Technical expertise, human judgment, and the time spent by an analyst are often believed to be key factors in determining the accuracy of forecasts obtained with the use of a time series forecasting method. A control experiment was designed to empirically test these beliefs. It involved the participation of experts and persons with limited training. Forecasts were generated for 25 time series with the use of the Box-Jenkins, Holt-Winters and Carbone-Longini filtering methods. Results of the nonparametric tests used to compare the forecasts confirmed that technical expertise, judgmental adjustment, and individualized analyses were of little value in improving forecast accuracy as compared to black box approaches. In addition, simpler methods were found to provide significantly more accurate forecasts than the Box-Jenkins method when applied by persons with limited training.
TL;DR: In this article, the photosynthetic 14C assimilation of phytoplankton from the St. Lawrence estuary was measured under various artificial light regimes, combining different intensities, colors, and high frequency fluctuations.
Abstract: The photosynthetic 14C assimilation of phytoplankton from the St. Lawrence estuary was measured under various artificial light regimes, combining different intensities, colors, and high frequency fluctuations. The light fluctuations consisted of rapid alternation of high and low light intensities of equal duration. In the first set of experiments, the photosynthetic response was measured under red, green, blue, and white light, steady or fluctuating (2.5 Hz). Under fluctuating light, the color: white 14C assimilation ratios were significantly higher than those under steady light. In the second set of experiments, light saturation curves were made under fluctuating (10 Hz) and steady lights. No differences were recorded for PBmax but the photosynthetic efficiencies α were 30% higher under fluctuating light. Vertical distribution of rapid light fluctuations, together with light intensities and color, is therefore of ecological significance. These experiments also raise the problem of deck incubations, where not only the color is modified but also the frequency of light fluctuations, leading to a median error as high as 30%.
TL;DR: In this article, the alga Spirulina maximima was subjected to mechanical (ultrasonic + mechanical disintegration) and thermochemical pretreatments and used as a substrate in anaerobic digestion.
Abstract: The algaSpirulina
maxima was subjected to mechanical (ultrasonic + mechanical disintegration) and thermochemical pretreatments and used as a substrate in anaerobic digestion. Results indicate that the pretreatments increased the solubility of biomass and had a positive effect on acid forming bacteria. Thermochemical treatments produced compounds toxic to methanogenic bacteria especially when treatment conditions became more severe.
TL;DR: The ability of two shrubby alders to form ectomycorrhizae with known species of fungus was investigated in this article, and the Hartig net was always confined to the epidermal layer of the root, never completely surrounding it.
Abstract: SUMMARY
The ability of two shrubby alders to form ectomycorrhizae with known species of fungus was investigated. Frankia- inoculated seedlings of Alnus crispa and Alnus rugosa were raised in growth pouches and inoculated with a pure culture inoculum of potential ectomycorrhizal fungi. Ten of the 46 species of fungi used formed ectomycorrhizae with both Alnus species. Only Alpova diplophloeus showed a well distributed Hartig net; others had a net only proximally, while others had none. These patterns are discussed in terms of more or less rapid Hartig net development. The Hartig net was always confined to the epidermal layer of the root, never completely surrounding it. This situation appears to predominate in the Angiosperms. Colonization of young actinorhizae by Alpova diplophloeus led to the formation of ectomycorrhizal structures.