Showing papers by "Agriculture and Agri-Food Canada published in 1974"
TL;DR: In this article, an orthochlorite (sheridanite) was heated to 610~ to dehydroxylate the hydroxide sheet and to oxidize ferrous iron.
Abstract: An orthochlorite (sheridanite) was heated to 610~ to dehydroxylate the hydroxide sheet and to oxidize ferrous iron. The heated sample was shaken for 20 min in a mixed solution of 0"2 N HCI and 0'2 N NaC1 to dissolve the dehydroxylated hydroxide sheet. X-ray diffraction, thermal, infrared absorption and chemical analyses showed that the resulting product was similar to Kenya vermiculite. The procedure shows promise for the individual determination of the composition of the hydroxide sheet and of the mica layer in the chlorite structure. The experiments indicate that the hydroxide sheet in orthochlorites must be structurally disturbed before it can be selectively removed. In nature, structural disorganization of the hydroxide sheet of chlorite by dehydroxylation and oxidation of ferrous iron might occur during meta- morphic processes, and chlorite to vermiculite transformation could take place during subsequent acid weathering. In pedogenic weathering conditions it is likely that oxidation of ferrous iron plays a major role in initiation of the structural disorder required for the selective removal of the hydroxide sheet in the weathering of chlorite to vermiculite.
68 citations
TL;DR: Aedes females that subsequently fed on sensitized mammals showed substantially reduced fecundity in another mosquito, Culex tarsalis, that fed on the same mammals, but other life stages of the mosquitoes apparently were not affected.
62 citations
TL;DR: A link between cold acclimation and winter survival may exist involving the structural and functional modifications in membrane structure which occur during Acclimation.
Abstract: The responses in membrane lipid composition, structure, and function of four cultivars of wheat (Triticum aestivum L.) to growth at low temperature have been investigated. Marked growth temperature-dependent alterations in the fatty acid composition and unsaturation of the mitochondrial phospholipids correlate with changes in respiratory activity in all the varieties. Parameters such as the respiratory control ratio and the phosphorylative efficiency decrease in cold-adapted seedlings. Three temperature-dependent structural transitions were identified in the mitochondria by the spin-labeling method. The structural transitions occur at lower temperatures in the cold-grown material. The shift in one transition appears to be quantitatively greater in the winter hardy varieties. Cold-induced changes in all of the other measured parameters were indistinguishable in hardy and nonhardy varieties. The results indicate major involvement of the phospholipid matrix in cold acclimation. A link between cold acclimation and winter survival may exist involving the structural and functional modifications in membrane structure which occur during acclimation.
60 citations
TL;DR: A facile chromatographic procedure is described for the isolation and purification of miserotoxin and new spray reagents are demonstrated for aliphatic nitro compounds and a colorimetric method is developed which is sensitive to 1 ppm miserot toxin.
35 citations
TL;DR: In this article, the authors used column-, thin layer-, and preparative gas chromatography to extract phenolic aldehydes and esters from the soil of a Podzol soil, and then oxidized with alkaline cupric oxide.
Abstract: Fulvic acid, (FA), extracted from the Bh horizon of a Podzol soil, was methylated and then oxidized with alkaline cupric oxide. The oxidation products were extracted into organic solvents, remethylated and separated by column-, thin layer-, and preparative gas chromatography into relatively pure components, which were identified by matching their mass and i.r. spectra and gas Chromatographic retention times with those of authentic specimens. The degradation products isolated and identified accounted for approximately 18 per cent of the weight of the initial methylated FA. Major oxidation products were: (a) methylated phenolic aldehydes and esters (66.9 per cent): (b) benzenecarboxylic acid methyl esters (14.6 per cent): (c) aliphatic dicarboxylic acid methyl esters (2.7 per cent): and (d) adsorbed materials such as n -alkanes (0.3 per cent), n -fatty acid methyl esters (0.3 per cent) and dioetyl adipate (15.2 per cent). The oxidalive degradation of methylated FA indicates the presence of two types of basic structural units: (1) those yielding phenolic aldehydes and esters, and (2) those producing benzenecarboxylic acids. Alkaline cupric oxide oxidation of methylated FA is relatively selective for the isolation of the phenolic components and appears to be a promising technique for structural investigations on humic substances.
34 citations
TL;DR: It was found that at maximal isotonic contraction the myofilaments pass through the expanded Z-regions, and the previously observed prolonged time course of muscle contraction seems to correlate with the present observations on the poorly developed sarcoplasmic reticulum and irregular distribution of transverse tubules.
25 citations
23 citations
TL;DR: A swarm of honey bees, Apis mellifera, which has lost its queen is capable of finding and rejoining her in a short period of time, and workers in a swarm prefer their own to a foreign queen.
Abstract: A swarm of honey bees, Apis mellifera , which has lost its queen is capable of finding and rejoining her in a short period of time. When given a choice, workers in a swarm prefer their own to a foreign queen. Accurate discrimination is contingent upon antennal and/or proboscal contact with both queens. Such discrimination appears to be based on the perception of small differences in hive odors. Hive odors are persistent substances which are adsorbed to the body surfaces of the queens. Upon finding and recognizing their own queen, the workers feed her and disperse Nassanoff pheromone, thus attracting other searchers. Upon finding and identifying a foreign queen, the workers react aggressively towards her, and signal her rejection by ‘marking’ her with alarm pheromones.
22 citations
TL;DR: Thirty-nine potential embryo transfer and 13 ovum collection experiments were initiated within a small experimental herd of mainly nulliparous cattle and results were obtained by collecting ova on Day 5 or 6 and using recipients within one day of being synchronous with the donor.
21 citations
TL;DR: It is concluded that these membranes are the major sites of synthesis of the dipeptide, γ-l -glutamyl- l -phenyl-alanine (γ-glu-phe), which accumulates in the blood during larval growth and is consumed upon the onset of puparium tanning.
20 citations
TL;DR: The properties of a tyrosinase inhibitor purified by column and affinity chromatography are described, indicating different entities even from the same sources.
TL;DR: Respiratory control values and ADP: O ratios show a general decline in mitochondria from seedlings of increasing age, whether grown in light or dark, and in both light- and dark-grown seedlings, oxygen consumption during state 3 respiration is severely inhibited by oligomycin.
Abstract: Mitochondria isolated from shoots of 2 days, light- and dark-grown winter wheat (Triticum aestivum L. cv. Rideau) seedlings oxidize α-ketoglutarate and l-malate with good respiratory control and ADP: O ratios. The efficiency of oxidative phosphorylation, and respiratory control are both reduced significantly when succinate or NADH is employed as substrate. Respiratory control values and ADP: O ratios show a general decline in mitochondria from seedlings of increasing age, whether grown in light or dark. In light-grown seedlings, the decrease in respiratory control with aging is due principally to a decrease in the rate of state 3 respiration, while in dark-grown material, the decrease appears to be due mainly to an increased rate of state 4 respiration. In both light- and dark-grown seedlings, oxygen consumption during state 3 respiration is severely inhibited by oligomycin. During state 4 respiration, 2,4-dinitrophenol stimulates oxygen uptake to a level approximately two-thirds the normal ADP-stimulated rate.
TL;DR: The parenchyma cells of three vegetable tissues varying in starch content as well as in textural response to freeze-thawing were studied ultrastructurally before and after controlled freezing regimes.
Abstract: The parenchyma cells of three vegetable tissues varying in starch content as well as in textural response to freeze-thawing were studied ultrastructurally before and after controlled freeze-thaw regimes. Similar tissue samples were also studied after blanching and after the blanch-freeze-thaw combination. Subcellular structures were altered more drastically by blanching than by freeze-thawing. There was much less fine structural disruption in the high starch tissue (green pea cotyledon) than in the tissues of lower starch content (spinach leaf and green bean pod) following all processing treatments. As judged by sensory evaluation, peas also underwent less textural change on processing than the other tissues studied. The minimal ultrastructural change observed in peas may be associated with certain cell characteristics: high starch content, abundant protoplasmic structure, and resultant low degree of vacuolation. It is concluded that - of these - the starch granule component is the major contributor to texture. This probably applies in the case of most processed vegetable tissues of relatively high starch content. The protective role of cellular starch is discussed in relation to fine structure retention and to texture.
TL;DR: The amount of water in larval tissues may be an indicator of the degree of malnutrition experienced by larvae of Tenebrio molitor on experimental dietary substrates.
Abstract: Larvae of Tenebrio molitor L., Gembloux strain, race F, tripled their initial fresh weight during a 4-week period, when fed a diet containing 10% of an amino acid mixture based on the protein of larval carcass and dextrin. They gained almost twice as much weight with this diet as with the same diet in which glucose was the dietary carbohydrate. Gains in weight were related to the concentration of amino acid mixture in the diet, the optimal concentration being 10%. They were also related to the dietary carbohydrate, being greater with dextrin than with glucose. On dextrin diets, larvae of Tenebrio molitor contained more water in their tissues when reared on diets with low concentrations of amino acid mixture than on diets with high concentrations. The amount of water in larval tissues may be an indicator of the degree of malnutrition experienced by larvae of Tenebrio molitor on experimental dietary substrates.
TL;DR: Electron microscopic observation showed the occurrence of unusual structures in the phloem of carrot root and aster stem tissue cultures, infected with the aster yellows disease, which lost their distinct outlines, became enlarged, and their membranes gave rise to layered structures.
TL;DR: In this article, a Varian carbon rod flameless atomizer was used to estimate trace amounts of selenium in biological samples by atomic absorption utilizing the Varian Carbon Rod Flameless Atomizer.
Abstract: Trace amounts of selenium in biological samples were estimated by atomic absorption utilizing a Varian carbon rod flameless atomizer. Samples were digested with nitric perchloric acids, selenium was separated from the interfering sample matrices by reduction-precipitation with ascorbic acid, redissolved in acid and five microliter aliquots were taken for analysis. For a variety of samples, the results were comparable with, but somewhat lower than, levels determined by fluoro-metry. Sensitivity and detection limit are 80 ng/ml and 60 ng/ml respectively; absolute sensitivity and detection limit are 4×10 −10 g and 3×10 −10 g respectively.
TL;DR: Mature seeds ofBrassica campestris var.
Abstract: Mature seeds ofBrassica campestris var. yellow sarson were extracted with hexane to yield free lipid. The residue then was extracted with chloroform-methanol to release bound lipid. Free and bound lipids were separated into polar and nonpolar fractions chromatographically. The nonpolar fraction of both free and bound lipid consisted mainly of triglycerides with small amounts of steryl esters, free sterols, mono- and di-glycerides, and free fatty acids. The principal components of polar bound lipid were phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, and steryl glycoside. In the free polar lipid, there was more phosphatidyl inositol and less phosphatidyl choline and phosphatidyl ethanolamine. Erucic acid content was much greater in the nonpolar fractions and in the polar free lipid than in the polar bound lipid.
TL;DR: The differences in fertility between the present hybrids and the only other rugosa x chinensis hybrid described, R. calocarpa(Andrê) Willmott, are discussed.
Abstract: Reciprocal crosses were carried out for 6 combinations of 4 R. rugosa with 3 R. chinensis cultivars. The parental combinations were evaluated for successful pollinations, seed germination and flowering and seed setting seedlings in populations of 3 year old plants. Seeds and viable seedlings were obtained from each of the 12 seedling populations. Only 3 populations produced female fertile offssprings. The average of seed setting seedlings was 1.5%. The percentage of flowering seedlings was significantly reduced in the offspring from certain parents. The success of cross pollination, seed germination and the ability to initiate flowers were influenced by cytoplasmic factors.
TL;DR: The presence of the chromosomal mutation dnaB43 in F prime strains of Escherichia coli growing at temperatures in the permissive range results in a reduction in the number of cells with surface attached pili determined by the F plasmid (F pili).
Abstract: The presence of the chromosomal mutation dnaB43 in F prime strains of Escherichia coli growing at temperatures in the permissive range results in a reduction in the number of cells with surface attached pili determined by the F plasmid (F pili). This effect is independent of temperature and is observed under conditions when DNA synthesis is not affected. It is reversed by the presence of 0.15 M KCl added to the growth medium. The observations indicate that this effect of the dnaB mutation on F piliation is over and above the effect of growth temperature on F piliation. It provides yet another indirect evidence to indicate that dnaB mutations affect the cell membrane.
TL;DR: The "ascorbic acid system" developed by BRODIE et al. (1954) is considered to be closest to biological systems and has been used successfully to oxidize aromatic substrates to give products similar to those observed in biological systems.
Abstract: Many attempts have been made in the past to develop chemical oxidation methods that would simulate biological oxidation processes (BUHLER and MASON 1961, HAMILTON et al. 1966, MERZ and WALTERS 1949). Fenton's reagent, consisting of hydrogen peroxide and ferrous ions, is known to give hydroxylation products from aromatic substrates similar to those obtained with liver microsomal systems (MERZ and WALTERS 1949). However, the "ascorbic acid system" developed by BRODIE et al. (1954) and UDENFRIEND et al. (1954) is considered to be closest to biological systems. It consists of L-ascorbic acid, ferrous ions, ethylenediaminetetracetate (EDNA) and soluble oxygen. It has been used successfully to oxidize aromatic substrates to give products similar to those observed in biological systems (BRODIE et al. 1954, UDENFRIEND et al. 1954).
TL;DR: Counterimmunoelectrophoresis detected antigen by the formation of precipitin lines with antibody within 1 h and promises to be a useful technique for detecting and identifying mycoplasma isolates in either pure or mixed cultures.
Abstract: Twelve reference strains of mycoplasma and acholeplasma previously reported to have been recovered from cattle were tested against hyperimmune rabbit serum by counterimmunoelectrophoresis. This technique detected antigen by the formation of precipitin lines with antibody within 1 h and promises to be a useful technique for detecting and identifying mycoplasma isolates in either pure or mixed cultures.
TL;DR: In this paper, an improved dough Extensigraph is described, which has replaced the standard mechanical sensing system and increased the precision of measurement and its operational flexibility by using an electronic system to record forces generated during dough extension on a rectilinear chart.
Abstract: An improved dough Extensigraph is described. An electronic system has replaced the standard mechanical sensing system. Forces generated during dough extension are recorded on a rectilinear chart. Cradle depression effects on the measurements are eliminated. Modifications of the Extensigraph increased the precision of measurement and its operational flexibility. The improved Extensigraph readings were correlated with standard Brabender Extensigraph results. Stress relaxation and effects of hook speed were studied. The application of this instrument for the study of the transverse breaking strength of spaghetti demonstrated its operational flexibility.
TL;DR: In this article, wheat grains were treated with 11 to 450 ppm of lindane-14 C. The treated grains were stored in closed containers at ambient temperature (with and without adding 10% water to the grains) and also a...
Abstract: Wheat grains were treated with 11 to 450 ppm of lindane-14 C. The treated grains were stored in closed containers at ambient temperature (with and without adding 10% water to the grains) and also a...
TL;DR: The use of newer agarose preparations, which gel at low temperatures, produced matrices of excellent clarity, and resolution of arcs was enhanced by steric exclusion of the antigen-antibody complexes to form precipitates of greater optical density.
TL;DR: In this paper, the AIS of the edible portion of apple tissue was isolated, purified and chemically modified to yield the sodium salt of the carboxymethylether, and the derivative was water soluble, of medium-high viscosity and showed signs of an ability to weakly gel a high solids sugar solution in the presence of calcium ions.
Abstract: The alcohol insoluble solids (AIS) of the edible portion of apple tissue were isolated, purified and chemically modified to yield the sodium salt of the carboxymethylether. The derivative was water soluble, of medium-high viscosity and showed signs of an ability to weakly gel a high solids sugar solution in the presence of calcium ions. This property is akin but not identical to the jellying characteristics of pectins. These findings are considered of interest to those studying the role of cell-wall material of apples during processing and storage.
TL;DR: In this article, several complex foods were evaluated in the electronic recording mixer and torque-time, torque-mixing speed, and torque sample size relationships were investigated for tomato paste, apple sauce, peanut butter and mayonnaise.
Abstract: Several complex foods were evaluated in the electronic recording mixer and torque-time, torque-mixing speed, and torque-sample size relationships investigated Tomato paste, apple sauce, peanut butter and mayonnaise showed non-Newtonian behaviour, characteristic differences were found between suspension and emulsion-type foods The instrument was calibrated with mineral oil of known viscosity Apparent viscosity equations were derived from the standardization graphs
TL;DR: An electrical network is presented as a model of the electrical connections between cells in a cross section of visceral smooth muscle, providing an estimate of the shunting effect of the current paths through parallel cells to make possible a more accurate interpretation of electrical measurements of intercellular resistance.