Showing papers by "The Hertz Corporation published in 1978"

Photorespiratory nitrogen cycle

Abstract: MOST temperate plants form phosphoglyceric acid as the first stable product of photosynthesis. These plants also photo-respire, that is, during CO2 fixation they simultaneously release CO2 to the atmosphere from the oxidation of an intermediate of the photosynthetic process1,2. The reaction below, which takes place in the mitochondria3,4, is chiefly responsible for this CO2 release.

The occurrence of some acid phosphatases and dehydrogenases in the vesicular‐arbuscular mycorrhizal fungus glomusmosseae

Abstract: SUMMARY The occurrence of acid phosphatase, glutamate dehydrogenase, succinate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glucose-6-phosphate dehydrogenase and NADH and NADPH diaphorases in Glomus mosseae (yellow vacuolate Endogone spore type) was demonstrated cytochemically. Acid phosphatase was found in lysing and growing fungal structures. It was inferred that the fungus possesses an Embden-Meyerhof-Parnas system, a tricarboxylic acid cycle and a hexose monophosphate shunt.

A comparison of methods for the extraction and separation of hordein fractions from 29 barley varieties

Abstract: Methods have been developed for extracting and comparing the hordein fractions of barley seed as a means of identifying different varieties. A rapid method involving a single extraction with 55% (v/v) propan-2-ol+2% (v/v) 2-mercaptoethanol at 60°C removed slightly less nitrogen from milled grain than a more detailed procedure in which three sequential extractions were made with the same solvent. The hordein fractions extracted by these two procedures were alkylated and their component poly-peptides separated by four one-dimensional and two two-dimensional systems. The results showed that the hordein extracted by both techniques had the same polypeptide composition and thus the rapid method was satisfactory for use in comparing varieties. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and isoelectric focusing were used to compare the polypeptide composition of the hordein fractions from 29 varieties. Using the former system a total of 11 different patterns were recognised while further small differences between several varieties were revealed by isoelectric focusing or two-dimensional analysis. If the polypeptide patterns obtained by these techniques are considered in conjunction with other grain characters it should be possible to identify almost all of the 29 varieties.

The suitability of soils for sequential direct drilling of combine-harvested crops in Britain: a provisional classification:

Abstract: A classification based on experimental results is proposed for the suitability of land in Britain for repeated direct drilling of cereals. Chalk and limestone soils and other well-drained loams are...

Tomato pith necrosis caused by Pseudomonas corrugata n. sp.

Abstract: SUMMARY A disease of mature tomato plants is described, the symptoms of which include brown discoloration and/or necrosis and collapse of the pith. These are sometimes accompanied by vascular browning, external dark brown to black stem lesions, bacterial flux from stem wounds and adventitious root formation. The disease, which appears to be favoured by high humidity and/or free water on the plant surfaces and by high N fertiliser, has been widespread on many glasshouse holdings in England since 1971 but has caused severe loss on only a few. It is thought to be caused by a new species of the genus Pseudomonas for which the name P. corrugata Roberts and Scarlett is proposed.

Unusual response of DDT-resistant houseflies to carbinol analogues of DDT

Abstract: THE toxic action of DDT is thought to be caused by complex formation between the insecticide and nerve protein, a mechanism consistent with the well known phenomenon of negative correlation between insect mortality and temperature1. We present here evidence which indicates that some carbinols which are close analogues of DDT may have a different mode of action. These compounds elicit very different symptoms of poisoning, and none of the major mechanisms of resistance to DDT in the housefly confers significant resistance to these compounds.

Varietal identification of single seeds of barley by analysis of hordein polypeptides

Abstract: Methods for the extraction and separation of hordein fractions from single or half-seeds of barley have been evaluated. Sodium dodecylsulphate-polyacrylamide gel electrophoresis at pH 8.9 gave rapid and reproducible separations of reduced and alkylated hordein, and this system was used to analyse hordein fractions from 88 barley varieties. On the basis of this character the varieties can be divided into 29 groups, each containing between one and 25 varieties. The largest group can be further divided into four subgroups on the basis of minor hordein polypeptide differences revealed by a second electrophoretic system, urea polyacrylamide gel electrophoresis at pH 4.6. Of the samples of the varieties studied, all except five contained seed homogeneous with respect to hordein polypeptide pattern. It is concluded that analysis of hordein polypeptide patterns from single seeds is of great potential value, both for the commercial identification of grain samples and as an aid to existing techniques for the establishment of varietal distinctness.

Petrography, stratigraphy and weathering of late pleistocene tills in east yorkshire, lincolnshire and north norfolk

Abstract: SUMMARY A study of the vertical and lateral variations in particle size distribution, mineralogy and other petrographic features of tills in East Yorkshire, Lincolnshire and north Norfolk shows that the Devensian glacial succession in eastern England contains only two tills, for which the new names Skipsea and Withernsea Tills are proposed. The “Hessle Till”, recognised as a third member by most previous workers, is shown to be the postglacial (Flandrian) weathering profile on whichever of these two occurs at the surface. South of Flamborough Head, the upper (Withernsea) till occurs on land only in an arcuate area adjoining the coast of south-east Holderness. The Skipsea Till occupies the whole of Holderness, and extends westwards on to the lower dip-slope of the Wolds and southwards to the northern coastal strip of Norfolk, where in its weathered form it has previously been known as the Hunstanton Till. These conclusions agree with those reached by Bisat forty years ago, but hitherto unpublished. The weathering of the tills involves decalcification, the softening and disaggregation of sandstone, shale, igneous and metamorphic erratics, clay alteration and translocation, and the alteration of micas and some heavy minerals in the sand and silt fractions. Reddish brown colours, previously regarded as characteristic of the “Hessle Till”, result from oxidation of pyrite and siderite to depths of approximately 5 m.

Pharmacokinetic and metabolic studies of the hypoxic cell radiosensitizer misonidazole.

Abstract: 1. The metabolism of the radiosensitizing 2-nitroimidazole, misonidazole, has been investigated in mice, rats, baboons, human volunteers, and in patients receiving radiotherapy for advanced malignant disease. 2. Plasma levels of unchanged drug and its desmethylated metabolite have been measured, and in humans there is good correlation of peak plasma concn. with drug dose. All drug-related material in plasma was accounted for as unchanged misonidazole or its desmethylated metabolite, both compounds being radiosensitizers in vitro. 3. Extensive faecal excretion of material not containing any nitro group occurred in mice, rats, and baboons dosed with radiolabelled drug. 4. Renal excretion is the preferred route of elimination in man, baboon and mouse. Nitroimidazole metabolites accounting for over half the urinary excretion in all species were identified. 5. The compound penetrates solid murine tumours in concentrations sufficient to achieve radiosensitization.

Optimally partitioning soil transects

Abstract: Summary Two methods are described for locating soil boundaries on transects from multivariate data. One method (split moving-window, SMW) examines a transect through a window which is split at its mid point and the two halves compared. The window is moved along the transect and a boundary inferred wherever the difference between the two halves attains a local maximum. The other (maximum level-variance, MLV) examines all possible partitions of a transect that can be produced by a given number of boundaries or less and places boundaries in those positions that minimize the within-segment sum of squared deviations from the segment means (and hence maximize the between-segment sum of squares). The performances of the two methods are compared for two soil transects in Oxfordshire. MLV identified all major changes even where gradual, but was less reliable for small changes. SMW identified all sharp boundaries, even between soil types that are fairly similar. In its original form SMW did not identify gradual changes reliably, but its performance was improved both by omitting data near the centre of the window and by concentrating the discriminating power of the data beforehand as in MLV. SWM requires less computing than MLV.

Detection of mutagenic derivatives of cyclophosphamide and a variety of other mutagens in a "microtitre" fluctuation test, without microsomal activation

Abstract: The fluctuation test recently introduced by Green et al. has been used on a ‘microtitre’ scale, to detect mutagenic activity in the breakdown product or products of CP formed during its storage in phosphate buffer. The mutagenic product(s) accumulated over a period of 72 h at 37°C, however after 7 days further degradation into non-mutagenic forms seemed to occur. At 23°C although a slower breakdown into mutagenic product(s) was observed, these persisted even after 7 days at this temperature. The breakdown product or products produced base-pair mutations in E. coli strains, WP2, WP2 uvrA, which appeared to be subject to the excision-repair system in this bacterium. Frameshift mutations were not detected using S. typhimurium strain TA98. The ‘microtitre’ fluctuation test was also used to detect a variety of other mutagens, including proflavin (an acridine); NG (alkylating agent); Nifuroxime (nitrofuran); Hycanthone (anti-schistosomal drug): AZ (azo-dye) and MMC (anti-neoplastic antibiotic). It appears to be as sensitive as the macroscale test, and it can be used with both the E. coli strains and Salmonella strains currently available. Because of its potential automation the use of a ‘microtitre’ system greatly extends the application of fluctuation testing as a general screen for mutagenic compounds. These tests involve chronic treatment of the test strains with low doses of mutagen, which corresponds more closely to the environmental situation.

Taxonomy and biology of Pyrenopeziza brassicae sp.nov. (Cylindrosporium concentricum), a pathogen of winter oilseed rape (Brassica napus ssp. oleifera)

Abstract: Pyrenopeziza brassicae Sutton & Rawlinson sp.nov., the teleomorphosis (perfect state) of Cylindrosporium concentricum Grev., is formally described from apothecia developed in culture. The taxonomic affinities of this fungus, the cause of light leaf spot or leaf scorch of Brassicae, are discussed. Its infection, symptomatology and novel occurrence on winter oilseed rape ( Brassica napus L. ssp. oleifera ) are described, including reference to possible seed-borne transmission. Factors influencing infection, disease incidence, spore dispersal and cultivar susceptibility are discussed in relation to disease control.

Soil erosion in north Norfolk

Abstract: Soil erosion in a field in north Norfolk is described. Gullies formed, one up to 2 m deep, 5 m wide and 214 m long, and from this gully about 450 t of soil was eroded. Other gullies and rills deposited about 275 t of soil. In the large (61 ha) field the area subject to erosion was small, about 2·5%. The soil, slope, cultural and rainfall factors which caused erosion are discussed. Erosion in this field is not a rare phenomenon and crop yields will be affected if erosion continues. A solution to the problem is suggested.

Racquet Player's Pisiform

Abstract: Four patients whose sport involved wielding a racquet presented with symptoms at the base of the hypothenar eminence which were due to minor degrees of subluxation of the pisiform. In two there was in addition a chondromalacia of the articular cartilage of the joint.

Morphology and histology of the antenna of Cydia nigricana (F.) (Lepidoptera: Tortricidae)

Abstract: The morphology of the antenna of male and female Cydia nigricana (F.) including the detailed mosphology and distribution of the different types of sensilla is described. Features of the internal structure of the sensilla that assist in their identification are reported. Six main types of sensillum occur on the antenna of both sexes and sexual dimorphism is mainly restricted to differences in the size and number of sensilla trichodea . The sensilla styloconica resemble those in other Lepidoptera and their structure suggests that they are contact chemoreceptors. The straight, blunt sensilla chaetica are easily distinguished from the sensilla trichodea and have both longitudinal and annular grooves on their surface. Sensilla trichodea and sensilla basiconica appear similar, being curved hairs with annular grooves, but are easily separated on the basis of length, and basal diameter. The sensilla trichodea are thick-walled and have 2 dendrites in males and up to 5 in females. Distortion of the annulations near the base of the sensilla gives the appearance of spiral grooves. Sections through sensilla basiconica indicate that there are 2 types; type I contains up to 9 dendrite branches, whereas type II contains approximately 20. Type II has not been found on female antennae. The sensilla coeloconica have been divided into two groups according to size and the number of teeth; they are distributed so that the majority point downwards during flight. The sensilla auricillica resemble flattened sensilla basioconica in that they have thin porous walls and many dendrite branches. They are distributed mainly under the scales on the dorsal surface of the antenna.

Studies on the lenticel development, surface microflora and infection by common scab (Streptomyces scabies) of potato tubers growing in wet and dry soils

Abstract: SUMMARY The mechanisms of control of potato common scab (Streptomyces scabies) by irrigation were investigated in 5 years by studying the growth and surface microflora of young potato tubers developing in wet or dry soils. Direct examination of the tuber surface by light or scanning electron microscopy showed that the newly formed internodes near the apex, which carry stomata, had a very sparse microflora. In dry soil the older internodes, which carry lenticels at a susceptible stage, were increasingly colonised by actinomycete hyphae and discrete, although sometimes large, bacterial colonies. In wet soil, actinomycetes were rarely seen on tuber surfaces but bacteria were generally scattered over them, differences not always shown by isolation from periderm pieces onto water agar. When dry scab-infested soil was wetted, scabs did not subsequently develop on the two youngest tuber internodes (A-1, A-2), which may be an example of disease escape rather than inherent resistance of the stomata. The scab control achieved in wet soil was probably caused by some form of microbial antagonism, but whether through competition or antibiosis was not established.

Red wine quality: Correlations between colour, aroma and flavour and pigment and other parameters of young Beaujolais

Abstract: In 15 young Beaujolais red wines from the 1974 and 1975 vintages statistically significant linear correlations were found between overall quality and the contents of total pigments, total anthocyanins, coloured anthocyanins and tasters' mean colour scores; and also between flavour and the contents of total pigments and total anthocyanins. In 1974 additional significant correlations were found between (a) overall quality and wine colour density; non-coloured anthocyanins and pH, (b) flavour and colour scores and coloured anthocyanins, (c) aroma and total pigments, total anthocyanins, coloured and non-coloured anthocyanins and pH and (d) the chemical parameters of pH and total pigments and total anthocyanins. In 1975 flavour was correlated also with non-coloured anthocyanins and pH. The results demonstrate the desirable effects of anthocyanins on wine flavour and quality, whereas the polymeric pigments formed on ageing of Beaujolais appear to be indifferent features of quality. Thus, the negative correlations found between quality factors and wine ‚chemical age’ tend to support the opinion that most Beaujolais should be drunk young. Comparison of the results with data on Australian and Swiss red wines suggests that sulphur dioxide affects not only quality itself but also the nature of the quality correlation found. Simple colour measurement of acidified wine provides a useful indication of quality in young red wines of the same grape cultivar and age, having minimal sulphur dioxide content.

Chloride leaching in the rothamsted drain gauges: influence of rainfall pattern and soil structure

Abstract: Summary Calcium chloride giving 253 kgClha−1 was applied to the 20-inch and 40-inch 1/1000 th acre drain gauges after drainage re-started in 1974. It was tagged with 30Cl in the 40-inch gauge. After two preliminary peaks in each gauge, chloride concentration was related to cumulative drainage in the 20-inch gauge with an overall pattern of peak, decline and tail, interrupted by subsidiary peaks, whereas in the 40-inch gauge it declined very slowly with marked fluctuations. Total chloride and 30Cl behaved similarly. A simple computer model simulated the main features of the relationship well for the 20-inch gauge, but less satisfactorily in the 40-inch gauge and only if water was assumed to move in a very small proportion of the clay in the lower half of the gauge. These simulations and some for model rainfall regimes suggested that the shapes of the relationships were greatly influenced by rainfall pattern and by retention of soil solution in fine pores during movement in larger pores. Possible effects of soil structure on leaching are discussed.

Interactions between pheromone traps for the pea moth, cydia nigricana (f.)

Abstract: Interactions between pheromone traps were investigated in a series of trap spacing experiments involving the pea moth, Cydia nigricana. Central traps in circles or lines of traps, always caught fewer moths than isolated traps. This effect was significant even when the radius of the circle or the spacing in the line was 100 m, indicating a range of attraction of at least this distance. In lines of three traps across the wind, the central trap caught fewer moths than the outer traps. In similar lines along the wind, the upwind trap caught more moths than either the central or downwind traps, whose catches were equal. An explanation for these results is proposed, based on overlapping trapping zones, and supported by independent field observations. The implications of these results for pheromone trapping in general are discussed. ZUSAMMENFASSUNG WECHSEL WIRKUNGEN ZWISCHEN PHEROMONFALLEN FUR DEN ERBSENWICKLER, CYDIA NIGRICANA (F.) Wechselwirkungen zwischen Pheromonfallen fur den Erbsenwickler, Cydia nigricana (F.), wurden in einer Versuchsreihe mit verschiedenen Fallenabstanden untersucht. Fallen, die je 100 μg (E,E)-8-10-Dodecadienylacetat auf Gummistopfen enthielten, wurden jeweils an einem Ort in mehreren raumlichen Anordnungen plaziert. An der zentralen Falle innerhalb eines Kreises oder einer Linie wurden immer weniger Falter gefangen als an isolierten Fallen. Dieses Resultat war sogar dann signifikant, wenn der Kreisradius oder der Fallenabstand in der Linie 100 m betrug. Demnach betragt die Anlockungsdistanz mindestens diesen Wert. Wenn drei Fallen quer zur Windrichtung angeordnet waren, fing die zentrale Falle weniger als die peripheren Fallen. Wenn drei Fallen in der Windrichtung angeordnet waren, fing die windaufwarts plazierte Falle mehr als die zentrale und die windabwarts plazierte Falle; bei den zwei letzteren war der Fang gleich gross. Eine Erklarung dieser Ergebnisse wird vorgeschlagen und zwar aufgrund sich uberdeckender Fangzonen und von Direktbeobachtungen im Feld. Folgerungen daraus werden diskutiert inbezug auf den Fang mit Pheromonfallen im Allgemeinen.

Assessment of soil potassium reserves available to plant roots

Abstract: Summary Successive extraction with Ca-saturated sulphonated resin is used to remove potassium from soils. The kinetics of K-release are analysed mathematically to define three simultaneous rate processes by the amounts and rate-functions associated with them. The diffusion coefficient (3 × 10-19 cm2 sec-1) calculated for the slowest process (suggested to be from the mineral matrix) is of the same magnitude as that for illitic clay minerals. The effect of K manuring on these parameters is evaluated from measurements on soils from the Nil and K-fertilised plots of the Rothamsted Classical Experiments. Based on this analysis, a procedure is suggested for deriving from a smaller number of observations the amount of K a soil would release in a given time, and the contribution of each process to this amount is demonstrated.

Effects of previous legume and oat crops on grain yield and take-all in spring barley

Abstract: Two experiments compared yields of spring barley following barley, oats, beans (Vicia faba), red clover (cut) and (one experiment only) oil-seed rape, and tested effects of trefoil (Medicago lupulina) undersown in the preliminary crops of barley and oats. N fertilizer was applied at two rates to preliminary crops, and four rates to the final crop in each experiment. Barley following barley suffered severely from take-all disease (Gaeumannomyces graminis var. tritici); barley after other crops was little affected. Other recognized soil-borne diseases were unimportant. Barley yielded less after barley than after other crops except where excessive N fertilizer caused lodging. Clover and beans left N residues equivalent to about 88 and 44 kg fertilizer N/ha respectively; undersown trefoil left inconsistent N residues. Couchgrass (Agropyron repens) was more prevalent after barley than after other crops.

Effects of systemic fungicides on vesicular-arbuscular mycorrhizal infection and plant phosphate uptake

Abstract: The effects of two systemic fungicides on vesicular-arbuscular mycorrhiza were investigated with a view to using them in the study of mycorrhizal phosphate uptake. Formation of mycorrhiza in clover roots was prevented by soil drenches of benomyl and thiophanatemethyl and the spread of established infections was halted. Immersion of fungal inoculum in suspensions of the fungicides reduced infectivity. However clover plants grown in benomyl-treated soil did not retain enough fungicide to affect the amount of infection after transplanting into benomyl-free soil. Benomyl and thiophanate-methyl soil drenches reduced phosphate uptake of inoculated onion and strawberry plants when grown in irradiated soil, but not in unsterile soil. The short term uptake of radioactive 32P was reduced by benomyl but the results were variable and further work is required to improve the technique.

Insecticidal activity of the pyrethrins and related compounds. Part XI. Relative potencies of isomeric cyano‐substituted 3‐phenoxybenzyl esters

Abstract: The insecticidal activities to Musca domestica L. and Phaedon cochleariae Fab. of a series of 3-phenoxybenzyl pyrethroid esters with a cyano substituent at the 2-, 6-. (R)-α-, or (S)-α-position are compared with those of the unsubstituted analogues. Only an (S)-α-substituent enhances activity; others diminish or almost eliminate it. (RS)-α-mixtures are generally less active than would be predicted from the potencies of their separate constituents.

Osmotic-stress and the hatching of globodera-rostochiensis

Abstract: When hatched juveniles are transferred from distilled water to 0.4 M sucrose or trehalose solutions their water content falls from 72% to 67%, the value observed for unhatched juveniles in eggs equilibrated with water. Juveniles move little after 6 hr immersion in 0.4 M or more concentrated sugar solutions, but dilution with water to give a sugar concentration 0.1 M restores many to active movement. Few juveniles emerge from cysts in solutions of potato-root diffusate or of an artificial hatching agent (0.4 mM picrolonic acid) which contain sucrose at concentrations 0.4 M. The evidence suggests that loss of solutes from the egg fluid permits hatching and supports the belief that changes in permeability of the egg shell precede other steps in the hatching process. Prolonged storage of second-stage juveniles is possible in 0.4 M solutions of sugars.