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  • 101
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS Doublet Paramecium tetraurelia contain either a single macronucleus which is substantially larger than that in a singlet cell, or 2 smaller macronuclei. Doublets have approximately twice the DNA content and twice the total protein content of singlets. The cell cycle of doublets is 164% as long as that of singlets, but the relative position of the macronuclear DNA synthesis period within the cell cycle is the same as in singlets. The DNA content of doublets is regulated so that differences in the number of macronuclei do not produce corresponding changes in DNA content; bimacronucleate doublets have only 27% more DNA than unimacronucleate doublets.
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  • 102
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS Triplet conjugants of Paramecium caudatum which appeared naturally in mating mixtures and those of Paramecium multimicronucleatum which were produced by conjugation-inducing chemicals were isolated. Triplet conjugants lasting for more than 3 h were stained to examine macronuclear events. In P. caudatum, only 2 triplets among 182 (1%) contained macronuclear fragmentation in all 3 members. The most frequently occurring triplets (79%) were those producing 1 cell without and 2 cells with macronuclear fragments. There were also triplets (17%) producing 1 cell with, and 2 without macronuclear fragments, and some (3%) with 3 cells that contained no fragments. The length of persistence of the triplet was not responsible for the occurrence of macronuclear fragmentation in the 3rd cell of the triplet. In P. multimicronucleatum, the same 4 classes of triplets occurred, but the most frequently occurring class was that consisting of 3 cells (91%) with macronuclear fragments. Induction of nearly 100% of triplets with 3 such cells was possible by isolating the triplets' from a culture which was treated chemically at about 24 h after the last feeding. Treatment with chemicals in starved cultures resulted in triplets with incompletely fragmented or nonfragmented macronuclei. Further, in P. multimicronucleatum, chemicallyinduced triplets involving only holdfast pairs to which the 3rd cells were uniting often produced 3 cells with fragmented macronuclei.
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  • 103
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS Observations were made on the ultrastructure of a species of Vorticella containing endosymbiotic Chlorella. The Vorticella, which were collected from nature, bore conspicuous tubercles of irregular size and distribution on the pellicle. Each endosymbiotic algal cell was located in a separate vacuole and possessed a cell wall and cup-shaped chloroplast with a large pyrenoid. The pyrenoid was bisected by thylakoids and surrounded by starch plates. No dividing or degenerating algal cells were observed.
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  • 104
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS Euglena gracilis strain Z, at a concentration of 106 cells/ml and in containers of ∽ 0.1-mm thickness, spontaneously forms dynamic ring patterns in the dark. These patterns are modified differentially by illumination with red and with blue light. The red light effect is abolished by treatment with an inhibitor of photosynthesis. Pattern formation is apparently the result of chemophobic responses to oxygen dissolved in the medium. Euglena can respond to both negative and positive concentration gradients, depending upon the absolute magnitude of oxygen concentration. The photo- and chemosensory transduction systems of Euglena interact at a stage which precedes the overt expression of motor responses.
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  • 105
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS The pattern of chloroplast development was followed in Euglena gracilis strain Z greening in media with a variety of fixed carbon and nitrogen sources. The greening pattern of cells grown in inorganic medium with added ethanol or glucose involves an inhibition of chloroplast development when compared to that of cells grown in inorganic medium alone. Several nitrogen sources were tested to ascertain their effectiveness in relieving the inhibition of chloroplast development by glucose. Of those, only 0.05% (w/v) (NH4)2 SO4 accelerated the recovery from the inhibition after most of the glucose had been removed from the medium by the cells. The other nitrogen sources tested were not effective. An inhibition of chloroplast development, similar to that observed in cells greening in the presence of glucose, was seen in cells greening in an ethanol-containing medium. These cells, however, had a different response upon the addition of 0.05% (NH4)2 SO4. They appeared to recover from the inhibition of chloroplast development, even before the ethanol was removed from the medium by the cells. A slight enhancement of chloroplast development was noted in cells greening in an inorganic medium with glycine or serine. Other amino acids tested had little or no effect.
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  • 106
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The carbohydrate which accumulates in the cytoplasm of the marine protozoon, Parauronema acutum, during normal growth was isolated, purified and characterized chemically. The highly purified material yielded only glucose residues following hydrolysis in 0.6 N HCl for 3 h at 100 C; measurement of total carbohydrate by the phenol-sulfuric acid method and by treatment with amylo-glucosidase and glucose oxidase gave similar values. Aqueous solutions of the purified material reacted with iodine to form a complex which exhibited an absorption peak at 456 nm with a shift to 484 nm in the presence of 50% saturated (NH4)2SO4. Digestion with α-amylase, β-amylase, and isoamylase yielded 71%, 45% and 8.3% hydrolysis, respectively. Treatment sequentially with both isoamylase and β-amylase gave complete hydrolysis of the polymer. The average chain length (CL) determined by the isoamylase procedure was 12. These observations are consistent with the view that the carbohydrate isolated from the protozoan is a polymer consisting of α-D-glucose residues arranged in chains containing α-(1→4) linkages with branch points containing α-(1→6) linkages occurring once on the average of ∼ 12 glucose residues and, as such, is indistinguishable from glycogen isolated from mammalian sources.
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  • 107
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Oocysts of Wenyonella baghdadensis sp. n. were found in the feces of 2 of 12 bandicoot rats Nesokia indica Gray & Hardwicke from the Baghdad area. Sporulated oocysts were subspherical to broadly ellipsoidal, 25.4 (18–22) × 20.8 (15–28) μm, with a 2-layered wall, the outer wall being mammillated, without micropyle, micropylar cap, residuum, or polar granule. Sporozoites were ovoid, 11.8 (9–15) × 8.4 (6–10) μm, with Stieda body and residuum. Two sporozoites in each sporocyst were elongate, with granular cytoplasm and a refractile globule, the other 2 were bean-shaped, without granules or refractile globule. Sporulation time equalled 3 days at 22–24 C. Entamoeba coli and Giardia sp. cysts were also found in 3 rats each.
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  • 108
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The schizogonic development of Leucocytozoon dubreuili in the kidney proximal tubule cells of the American robin, Turdus migratorius, was studied by electron microscopy. Renal schizogony is initiated by the entry of certain hepatic merozoites into cells of the proximal tubules. Development of the schizont consists of a coordinated sequence of events including extensive mitotic nuclear division, multiplication of mitochondria, increase in endoplasmic reticulum and ribosomes, differentiation of membranes, microtubules, micronemes and rhoptries, and cytoplasmic segmentation (cytomere formation). Merozoites form by budding around numerous centers in the schizont and, when mature, are bounded by a single plasma membrane subtended by microtubules. Each merozoite contains a large nucleus, a mitochondrion, and a well developed apical complex consisting of 3 polar rings, paired rhoptries, and numerous micronemes.An atypical nuclear division observed in some maturing schizonts was characterized by the multiple fission of a nucleus within a persistent outer nuclear membrane and the absence of mitotic spindle apparatus. Alterations in infected renal cells consisted of disorganization and loss of cytoplasmic organelles and the accumulation of lipofuscin-like inclusions.
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  • 109
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. The life cycle of a turkey strain of Eimeria dispersa Tyzzer was studied in Beltsville Small White turkeys. There were 4 asexual generations. Mature schizonts of the first generation were present 30 h postinoculation (PI); those of the 2nd, 3rd, and 4th generations were present 48, 72, and 96 h PI, respectively. Average size of schizonts and number and size of merozoites for each generation were as follows: first, 14.3 × 13.0 μm with 19.2 merozoites, each 4.5 × 1.2 μm; second, 8.0 × 7.2 μm with 13.5 merozoites, each 4.5 × 1.1 μm; third, 8.9 × 8.9 μm with 15.1 merozoites, each 5.6 × 2.1 μm; fourth, 11.6 × 10.5 μm with 6.7 merozoites, each 8.2 × 2.0 μm. Sporozoites and developmental stages of the first generation were in close association with an epithelial cell nucleus and located between the brush border and the “row” of epithelial cell nuclei; developmental stages of the other 3 generations were not associated with a nucleus and were located just under the brush border. Early macrogametes and microgametocytes were present 96 h PI. Development was confined to the epithelial cells of the villus and extended from the tip of the villus to ∼ 1/2 the distance down the sides in all areas of the intestine except the cecum. The prepatent period was between 114 and 120 h. Percentage of sporulation was 15, 57, and 90, at 24, 36, and 48 h, respectively. Sporulated oocysts averaged 24.5 × 20.2 μm.
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  • 110
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Macronuclei of Paramecium primaurelia were isolated and examined by scanning electron microscopy. These nuclei consisted of a closely packed array of chromatin bodies measuring ∼ 0.2 μm in diameter. We estimated there were ∼ 30,000 such bodies/macronucleus, 20 times more than the number of unit genome equivalents. This suggests that a unit genome is physically shared by several chromatin bodies.
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  • 111
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. A quantitative method for the analysis of cirral patterns in the genus Euplotes is developed and contrasted with alternative approaches. Inherent variations in cirral pattern, as they are reflected in frequency distributions of intercirral distances, are ascertained through subclonal analyses of Euplotes harpa samples grown under different conditions. This assessment of the extent of variation within a form having 10 frontoventral cirri provides a basis for a comparative study of other Euplotes of cirrotype 10. These results suggest that all marine cirrotype 10 forms with a single dargyrome have the same configuration of frontoventral and transverse cirri. Similarly, most marine double dargyrome forms of cirrotype 10 have this same cirral pattern, and thus constitute variations upon the same morphometric theme.
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  • 112
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    Oxford, UK : Blackwell Publishing Ltd
    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: RÉSUMÉ. Des expérimentations portant sur des cellules isolées ont montré que 77% des microstomes de Tetrahymena paravorax, prélevés au hasard dans des cultures en phase logarithmique de croissance, se transforment directement en macrostomes en présence de “stomatine.” Ces macrostomes apparaissent à des moments variés entre 1,5 et 9 h après l'addition de la stomatine (“point 50% de transformations” vers 2,5 h). La compétence pour le remplacement oral est en relation avec la position dans le cycle cellulaire. Les pourcentages de transformation les plus élevés sont observés avec les populations testées pendant la première moitié de la période moyenne d'interfission. La formation des macrostomes est d'autant plus rapide que l'ǎge initial des microstomes est plus proche du point médian du cycle cellulaire (“point de compétence”). Dans la seconde moitié de ce cycle, le temps moyen de transformation reste à peu près constant, mais le pourcentage de divisions augmente: le “point de transition” (50% de divisions) se trouve au début d'une phase terminale représentant 19–20% de la durée totale du cycle. La transformation des produits de bipartition antérieur et postérieur est nettement asynchrone: dans la majorité des paires cellulaires, l'opisthe se transforme avant le proter. Les cellules-soeurs se divisent aussi de manière asynchrone: le temps de génération du proter est plus long que celui de l'opisthe.Le problème de l'acquisition de la compétence pour le changement de phénotype est discuté en envisageant les corrélations éventuelles avec certains processus majeurs du cycle cellulaire.SYNOPSIS. Seventy-seven percent of the microstomes of Tetrahymena paravorax taken from random samples of log-phase cultures transform directly into macrostomes in the presence of “stomatin.” These macrostomes appear between 1.5 and 9 h after addition of stomatin (“50% transformation point,”∼ 2.5 h). Competence for oral replacement is related to the position in the cell cycle. The highest percentages of transformation are observed in populations tested during the first half of the mean interfission period. Formation of macrostomes is more rapid when the initial age of the microstomes is nearer to the midpoint of the cell cycle (“competence point”). In the 2nd half of this cycle, the mean transformation time remains approximately constant, but the percentage of cells undergoing division is increasing. The “transition point” (50% divided cells) is found at the beginning of a terminal phase which accounts for 19–20% of the cell cycle. Transformation of anterior and posterior fission products is fairly asynchronous; in the majority of individual pairs, the opisthe is transformed before the proter. The daughter cells also divide asynchronously, the generation time of the proter being longer than that of the opisthe. The problem of acquisition of competence for phenotypic change is discussed in light of possible correlations with certain major processes of the cell cycle.
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  • 113
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    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Following electroshock-induced extrusion of its inserted trichocysts, Paramecium tetraurelia rapidly begins replacement of the population of lost organelles. Light microscopy of the cortical insertion of new trichocysts reveals a series of characteristic motility activities. An uninserted trichocyst in the cyclotic flow of the cell appears to be “captured” and removed to the noncyclotic, subcortical regions. The trichocyst then makes a series of saltatory motions which apparently serve to transport it to the cortex, with proper orientation (tip first) for insertion. Trichocyst saltations end with either cortical insertion of the organelle, or return to cyclosis. If the trichocyst is inserted, it makes a series of unique pivoting movements around the motionless tip. This form of motility, termed “wobble,” continues for a short period of time. After cessation of wobble, the insertion of the trichocyst is apparently complete, since no further motility is observed. With the aid of these observations it was possible to identify saltatory motility as the means for transporting trichocysts to the cortex for insertion, and also to observe a motility of unknown significance (wobble) apparently associated with the process of cortical insertion.
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  • 114
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    The @journal of eukaryotic microbiology 25 (1978), S. 0 
    ISSN: 1550-7408
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: SYNOPSIS. Symbiosis between Chlamydomonas hedleyi (Lee, Crockett, Hagen & Stone) and Archais angulatus (Fichtel & Moll) was examined during laboratory studies of primary production and light-enhanced calcification. Photosynthesis and calcification are directly proportional to light intensity in the range of 0–200 μEinsteins m-2 sec-1. Calcification in the light is directly proportional to photosynthesis and proceeds at rates that are 2–3 times that observed in the dark. The herbicide 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), in concentrations of 1–100 μM, completely inhibits photosynthesis and light-enhanced calcification. Calcification of the foraminiferan test is therefore due to the photosynthetic activity of the symbiote. Calcification rates for foraminifers incubated in the dark or with DCMU are not significantly different from the calcification rates obtained for dead foraminifers. Rates of calcification obtained with 45Ca are twice that obtained with 14C.
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  • 115
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: Income redistribution studies on the macro–economic level have been undertaken in Denmark for the years 1938–39, 1949, 1955, and 1963. By use of national accounts figures and all other available statistics, it was on certain assumptions possible to distribute public sector income and expenditure by income groups.A quite different approach is used in a Danish redistribution study on the micro-economic level for 1971, which relies solely on the comprehensive data from the family budget survey for that year. Unfortunately this study only relates to employee households.This paper deals with the 1963 and 1971 studies. First it describes and discusses the differences in methodology between the two studies and indicates some ideas for future studies in this field in Denmark. In the following sections some main results of the two studies are given, briefly for the 1963 study and more comprehensively for the 1971 study. The studies show the great and growing strength of the policy of redistribution through public sector income and expenditure in Denmark.It is the opinion of the authors that the appearance of redistribution studies based on comprehensive family budget surveys makes for a substantial improvement of redistribution figures, and that the purely micro-level frame of reference makes it possible to interpret the results in a more satisfactory way than before. Furthermore, the appearance of detailed input-output based national accounts data should bring about further improvements in redistribution figures through better data on indirect taxes and subsidies as well as supporting data which are necessary to link the micro and macro levels in a consistent way.
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  • 116
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: It is often discussed that inflation introduces a substantial, arbitrary and regressive redistribution of income and wealth under even mild inflation. But after a quarter century of experience with inflation in postwar Japan, very little is known about these costs of inflation on an empirical basis. Due to the complexity of the evaluation of the redistributional impact on Japan, the present paper analyzes the effects of inflation on individuals or groups as wage earners, debtors and creditors, taxpayers, and holders of real estate.The main results of the present investigation suggest that the Japanese inflation for 1955–75 did not seem to introduce much inequality in the income (flow) account in the economy, but that the inequality between households has appeared more in the wealth (stock) account, especially between the house-owner groups and non-house-owner groups. These observations are mainly derived from the following investigations; (i) the wage lag hypothesis about inflation, even if not wrong, does not seem acceptable when applied to the entire period (1955–75) as well as to each of the five sub-periods; (ii) there has been a substantial transfer of real purchasing power from households to non-financial corporations, and, to a lesser extent, to government entities in the debtor-creditor redistribution; (iii) among households, the most substantial redistribution takes place from the non-houseowners to houseowners with land, because of the huge amount of capital gains from the rapid increase in the price of real estate relative to the prices of other assets or the consumer price index, except for the last three years of rampaging inflation.
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  • 117
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: Preliminary estimates of the total incomes system of accounts (TISA) are provided for 1959 and 1969. They extend conventional accounts to include all consumption services produced by government and households as well as by enterprises, but define household purchases of durable and semi-durable goods as investment. Acquisitions of capital throughout the economy, intangible as well as tangible, and not only in the business sector, are included in capital accumulation along with, for tangible capital, net revaluations, that is capital gains net of increases in the general price level. Imputations are offered for non market consumption and capital accumulation, most prominently in unpaid household work and education. Much of government output, particularly police services and defense, is recalculated as intermediate, along with expenses related to work, while media services, treated by the United States Bureau of Economic Analysis (BEA) as business purchases of intermediate product, enter into TISA consumption. Subsidies are included in the value of product, as are services of volunteers and imputations for the underpayment of military conscripts and of jurors. Separate accounts are offered for the national income and product, business, nonprofit institutions, government enterprises, government and households.The ratios of BEA to TISA Net National Product were 81.4 percent and 76.5 percent in 1959 and 1969, respectively. BEA national income was 74.1 percent of the corresponding TISA net national income in 1959 and 69.6 percent in 1969, reflecting a greater per annum rate of growth of TISA net national income, 7.49 percent, as against 6.82 percent for the corresponding BEA national income.BEA gross private domestic investment, restricted to business acquisitions of tangible capital at original cost, was estimated as only approximately 22 percent of comprehensive TISA gross domestic capital formation in 1959 and some 20 percent in 1969. The BEA net private domestic investment growth rate of 7.32 percent per annum from 1959 to 1969 may be compared with a TISA net domestic capital formation growth rate of 9.42 percent.
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  • 118
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This paper is in 7 sections. Section 1 gives as background a chronological account of the steps taken in the United Kingdom, from 1974 to late 1977, towards the development of a new system of accounting in company reports which would allow for the effect of changing costs and prices on the measurement of profit and of capital employed in the business. Section 2 discusses the main features of the system, known as current cost accounting, as it is seen in the United Kingdom. Section 3 surveys the relationship between current cost accounting and the national income and expenditure statistics, and the likely implications of the introduction of current cost accounting upon the quality of macro-economic statistics, including estimates of national and sector balance sheets. Section 4 describes some of the problems of implementing current cost accounting, particularly in special situations, and outlines the solutions which were proposed in the “Exposure Draft” published in 1976 by the accountancy profession in the United Kingdom. Section 5 considers the definition of distributable profit in relation to the need to maintain capital, considering the concept of gain, the system of valuing assets and liabilities, and the enterprise's capacity to take on additional debt as a means of financing its assets. Section 6 briefly surveys the implications for taxation, price control and price setting. Section 7 concludes by surveying the scene at the end of 1977 and by looking at likely future developments.
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  • 119
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This article explores the assumptions underlying present definitions of national income in its principal uses, and considers the alterations that would be needed to allow for the inclusion of environmental quality. A numerical example illustrates the impact of alternative measures. The discussion concludes that if we want national income to conform more closely to theoretical concepts of welfare indices, then we need to include a proxy for those environmental services that would not be completely free goods if it were possible to overcome their inherent non-marketability. The least unsatisfactory proxy would be the spending on environmental protection.
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  • 120
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This paper examines the causes and consequences of the inflationary process in terms of its impact upon the national accounting flows, illustrated by the case of France during the period 1966–76. The first section of the paper discusses the apparent causes of inflation, and lays out the circuits through which inflation is propagated. The second section looks behind the apparent causes to examine more closely the reasons for the observed behavior. The final section considers the consequences of inflation in terms of factor allocation, and in turn its impact upon unemployment, the balance of payments, and the rate of growth.
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  • 121
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: In the June 1977 issue of the American Economic Review extraordinary attention was given to the statistical problem of measuring the effect on inequality in current income arising from differences associated with age. The method adopted by Paglin was severely criticized although everyone recognized the value of Paglin's unusual, if not original, emphasis on the importance of the underlying issue.This paper is not primarily concerned with the statistical problem of correcting data on current income distributions for income-age differences. It is concerned mainly with the lifetime income perspective itself-with ways of viewing the long-term path of persons and of ways of viewing inequalities in that path as they develop within and among different generations.The paper discusses issues of measurement on a birth-cohort or longitudinal basis, recent trends for selected cohorts, intra-and inter-cohort variances in lifetime income, and various policy issues, for example, the equity of the U.S. Social Security System viewed on a lifetime dimension.
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  • 122
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: This article reports on the plans of the member countries of the Council for Mutual Economic Assistance (CMEA) in the area of the purchasing power parity comparisons of national product and similar aggregates. A series of comparisons of the U.S.S.R. with other individual member countries was made for 1959,1966, and 1973. A new series will be undertaken for the year 1978. The scope of the program will be expanded to cover several new aggregates, including productivity concepts and total consumption of the population. The article discusses the conceptual and methodological problems and plans. Among other matters, attention is being given to the possibility of reducing the number of specifications priced, without sacrificing accuracy.
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  • 123
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    Review of income and wealth 24 (1978), S. 0 
    ISSN: 1475-4991
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Economics
    Notes: The problem of identification and classification of off-shore financial flows and extra-territorial funds is discussed with special reference to the case of the “captive” insurance market in Bermuda. The problem is examined in the context of the UN SNA definitions relating to the evaluation of insurance activities and the difficulty of gaining access to relevant and complete data. The conclusion is reached that the conduct of off-shore financial operations by local institutions and the resulting surpluses generated remain essentially extranational and thus contribute very little to the domestic value added of the tax haven concerned. Furthermore, by its very nature, information relating to the transactors involved, as well as the value of their transactions, is difficult to obtain. This raises a much wider issue, however, as to whether such surpluses are ever identified in any country's national income estimates.
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    Notes: This paper has two main points. First, the usefulness of the industry detail called for in the SNA would be increased if it were altered to facilitate the construction of price and quantity aggregates classified by stage-of-process sectors. Second, the price and quantity data so arranged should be augmented by data on behaviorally related variables classified the same way. The feasibility of the stage-of-process approach is demonstrated by a table showing the high degree to which the U.S. input-output table for 1967 can be triangularized. The analytical usefulness of the approach is demonstrated through analysis of changes in prices, output, unfilled orders and finished goods inventories for primary and for finished goods manufacturers.
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    Notes: This article proposes a method of characterizing the growth process using two parameters, a production index measuring growth, and a structural change index measuring the changes in the composition of output. It discusses the properties of the structural change index that is developed, including its relation to the bias in growth rates measured by conventional index numbers. It then applies the measure to an examination of Yugoslav industry for the period 1952–71.
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    Notes: Expanding a conventional national accounting framework in order to include activities that are not produced or consumed via ordinary markets requires the accountant to adopt some procedure for assigning unit values to these activities. Often, as is the case with governmental services, unit values are equated with unit costs of production.This paper argues that the appropriate valuation generally differs depending on whether the activity is viewed from the perspective of the producer, the consumer, or society. The theoretical justification for this position is developed first for the case of nonmarketed environmental services and then for in-kind governmental transfers.Rather than choosing a single unit value, the paper argues for and outlines an accounting system that will permit the simultaneous adoption of more than one valuation. Techniques for implementing the system for the environment and for in-kind transfers are discussed.Finally, drawing on the experience of the authors, the paper argues for the importance of developing data sets with more than one valuation. The authors claim that the effort to implement the system has generated valuable ancillary data sets even though data limitations and unresolved methodological questions have precluded complete implementation.
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    Notes: The paper presents some estimates of the imputed dollar value of household work (HW)for Canada in 1961 and 1971, finding this to be about $16 and $38 billion respectively, equal to 40 percent of GNP. From the results we derive some implications about five questions raised in the relevant literature. First, no clear evidence of a downward trend for the ratio HW/GNP is found, contrary to U.S. results. Second, addition of HW to GNP as a welfare measure does not affect the general pattern of past growth estimates. Third, a cost–by-function method of estimating HW is found superior in its theoretical support and the detail it provides, but the opportunity-cost method, despite doubts on its theoretical validity, gives a good approximation in the aggregate, and, being simpler, is likely to remain popular. Fourth, disaggregation does matter if detail by region or family type is required, in which case data by number and ages of children and market-employment status of females are needed; for the total, a reasonable estimate (6–7 percent error)is given by further aggregated data. Fifth, sensitivity of HW to accuracy in the data used is large only for female wages chosen, in particular for the function “cooking”. Finally, though available data must be manipulated to fit the needs of HW, especially for earlier years, the extent of this is not all that much more than is commonly found for GNP estimations.
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    Notes: This paper discusses the problem of valuing the time spent on household production and presents estimates of that production for the United States in 1960 and 1970. The estimates are derived by using both opportunity cost and market cost valuations of household time. A comparative analysis of these estimates concludes first that opportunity cost estimates exceeded market cost estimates by 1.0 to 3.0 percent of the GNP. Second, the ratio of household production to the GNP, although declining slightly between 1960 and 1970, may in the long run tend to be relatively stable. These conclusions do not support the popular views that over time household production will decline in relative magnitude, or that the opportunity cost method of valuing household time, relative to the market cost method, is significantly upward biased.
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    Notes: Construction has traditionally constituted one of the problem areas in the preparation of industry price and quantity statistm with in the system of national accounts of most countries. The difficulty stems from what is considered to be the unique character of construction projects. This has unnecessarily impeded the calculation of output price indexes and has resulted in the use of various input-based prices as proxies for output prices.One of the objectives of the development of the system of construction price statistics described in this paper is to permit deflation of the outputs of construction industries in order to produce industry output data in constant prices in a manner consistent with measures for the rest of the economy. This is a more promising approach to improving constant price industry and expenditure measures within the SNA framework than attempting such improvements through the collection of a vast array of quantity data.Construction industries sell specified configurations of materials-in-place which are, to borrow the jargon of other fields, sub-assemblies of some total system. As in other areas of industrial pricing, some of these products are simple and some are complex. Trade contractors sell these sub-assemblies or commodities mainly to an owner-builder or to a general contractor who, in turn, resells the trade contractors’ commodities along with whatever sub-assemblies the general contractor has produced. These sub-assemblies, when combined with, for example, the relevant outputs (or sub-assemblies) of manufacturers, the design services of service industries and the purchasers’ own contributions, yield the wide variety of plant and structures which constitute the various classes of gross fixed capital formation, which are not typically solely the outputs of the construction industries.The resulting contractors’ selling price indexes will provide deflators for the whole range of outputs of the various construction industries. These will become part of the system of industry selling price indexes from which relevant indexes for the various goods and services can be selected and combined with appropriate weights to yield arrays of deflators for the highly complex capital expenditures of business, institutions and government.Ultimately this integrated system of construction industry statistics will permit the preparation of gross output and value added measures, in both current and constant prices, to be calculated for the construction industries as an integral part of the Canadian System of National Accounts, as well as provide a key element for improving the deflation of fixed capital formation.
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    Notes: The constant price method is used here to evaluate transfers related to inflation either between households and other economic agents (essentially enterprises) or among groups of households defined by occupation, age class and so on. The results obtained are only fragmentary due to a lack of many pieces of information. The method requires in fact the splitting up of every value variation into a price component and a size component.Nevertheless, some interesting results are shown. In recent years, if the total productivity surplus has always been positive, the wealth surplus of households is sometimes positive, sometimes negative. Concerning the distribution of the productivity surplus among household groups, it has not been possible to find significant distortions, other than those which are related to differences in the propensity to save. On the contrary, marked distortions appear in the distribution of the wealth surplus due to wide differences in estate composition and indebtedness level.
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    Notes: As a basis for judging how public policy affects the poor, this article explores how “poor” families may be defined and how well such families can be distinguished from other families in the less developed countries. This is done by seeking proxies for poverty which are relatively easy to measure, accurate in discriminating between the poor and the non-poor, and relevant to public policy. To this end, a highly parsimonious model is developed, based on truncation and regression procedures, using only family size and number of wage earners in addition to either income or an education-age combination. Application of this model to data from household surveys in three major cities of Latin America shows that the model is highly effective in pinpointing poverty households, although the pattern of errors is not random, the most frequent type of error being to classify poverty households as non-poor.Especially significant is that the model is nearly as effective for discriminating poverty households from others when financial variables are excluded as when they are included. This would suggest that a good deal of flexibility exists in deciding what variables to include in future studies of this type. The results also suggest that even better results should be possible if more complete information is obtained on the employment status of the different members of the household and on the contribution of each to household income. Ideally, the data collection and model development should proceed in an iterative manner since there are numerous possible variables as well as alternative model formulations.
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    Notes: Unlike most developing countries, the Philippines has had several (four) reasonably comparable family income and expenditure surveys, covering a reasonable period of time (15 years). This study draws on those surveys and on wage data in an attempt to judge how, if at all, the distribution of income has been changing. The household survey data shows a declining share of both income and consumption for the top income groups; for the bottom quintile the share of recorded income fell while that of recorded consumption rose. When possible biases of the data are allowed for, it is hard to argue that either a narrowing or widening of income differentials occurred over these years. Real wages of a number of important occupations appear to have fallen, however. Only a partial reconciliation of the trends indicated by these wage series and the income trends for various occupational groups implicit in the household survey data was possible, indicating either data problems or the need for more subtle interpretations of the data. Since structural change in the labour force has been rapid (an increasing share being found in the high income occupations as time passed), declining wage rates for certain lower income groups cannot be taken to imply a general worsening of distribution. Our final conclusion is that distribution has probably changed little, and is about as likely to have changed one way as the other.
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    Notes: The paper reports on several results from a comprehensive study of the household incidence of public expenditure in Peninsular Malaysia in 1974. The results for education show a pro-poor distribution of expenditure when measured as a share of household income. Using however the criterion of each according to his needs (that is the number of school-age children per household) reverses this outcome. In agriculture, because of the importance of land settlement, benefits from public expenditure distribute predominantly in favor of the poor.The research differs from the usual study of this kind in that individual government outputs such as school years, or fertilizer loans, were defined, and in the case of education their unit costs estimated and their distribution across households measured. In the case of education, both the costs of services from capital and the households’ out-of-pocket educational costs were added to the current subsidies. As one consequence, it was seen that total expenditure for education in Malaysia exceeds one-eighth of GNP, nearly double the conventional estimate. Equally important, for the poor the burden of private costs for education even within a public system were seen to be very high.The contrasts between the strong results for education, a broad based social service, and the less conclusive results for agriculture, an economic service which impacts directly on production, were instructive in suggesting the limitations of such research in measuring the effects of government budget activity on distribution.
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    Notes: To adjust business accounting for inflation, one current proposal is to convert all dollar figures in existing financial statements to units of fixed general purchasing power. A widely offered alternative is to retain the dollar units but replace the historical-cost figures by current values. The two alternatives would yield very different results. After reviewing these and variant proposals, the analysis concentrates on certain major issues: the unit of measurement; the treatment of capital gains; the concept of capital maintenance; and the treatment of changes in the purchasing power of debt. Current value accounting would not correct for changes in the general price level and would involve far more difficult problems of concept and measurement than general purchasing power accounting. The latter is therefore preferable.
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    Notes: In this paper, we reclassify U.S. input-output data along functional lines by analyzing the use of products represented in the detailed coefficients of the 1967 interindustry study. Our new categories comprise 11 producing “industries,” services (nonproduction), energy (nonproduction), marketing, distribution, other general, crude materials, semi-finished materials, energy production, service production, and machinery replacement, furnishing products to 80 consuming industries. This functional input-output system is then used to analyze postwar structural change in the American economy. Distinct shifts in the uses of different types of inputs are indicated and the implications of these results are discussed.
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    Topics: Geosciences , Physics
    Notes: The method of finite differences is applied to the computation of multi-dimensional synthetic seismograms. This paper gives a study of the mathematical and numerical formulations of the problem, the boundary conditions, the convergence conditions and how to simulate the source in both one solid or a liquid. It is shown that the numerical formulation chosen is valid both for direct and inverse problems (i.e. for modeling and migration). This formulation makes it possible to use the normal incidence reflection coefficients for P and S waves, whether they travel horizontally or vertically. The examples shown have been chosen on purpose in order to be easily interpreted. They do not give a full idea of the possibilities of the algorithm which allows to consider non-planar interfaces, except close to the vertical axis.
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    Notes: Finite difference migration has been developed and popularized by J. F. Claerbout of Stanford University and is now widely used in seismic processing. For most sections finite difference migration gives results comparable to those obtained by conventional Kirchhoff migration and, where events are not dipping too much, a cleaner appearance is often apparent. However, there are two practical limitations to the method, and these occur in regions of very steep dip and where there is a large variation of the velocity in the lateral direction.It is possible to develop successively more accurate equations to deal with the steep dip problem, but above third order these schemes become prohibitively expensive to implement. The finite difference method itself introduces errors and so imposes further limitations on the angle of dip. For the effective treatment of steeply dipping beds there appears to be no method available in the time domain which does not suffer from dispersion inaccuracies. However, by developing wavenumber migration, an exact one-way wave equation can be used, and this eliminates any error except that caused by finite sampling.The other difficulty with wave migration is the correct migration in regions with lateral velocity variation. A number of approaches are possible of which three are discussed here. The first uses an exact theory, the second is based on the deviation from a depth stratified model, and the third uses a transformation to a depth co-ordinate system. All methods are discussed with their advantages and limitations. Finally, some examples are shown of wave migration applied to synthetic and real data.
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    Notes: In seismic refraction surveys, in particular those using first arrival recording techniques, the hidden layer problem occurs where energy from a refractor of higher velocity arrives at the surface before energy from an overlying refractor. The maximum thickness of the hidden layer is referred to as the blind zone.Hypothetically, every recorded refractor has an associated blind zone which may or may not contain a hidden layer. For an assumed earth model of plane constant-velocity layers and stepwise increase of velocity with depth, the effect of a blind zone on an interpreted depth section may be evaluated by defining an intercept time for a blind zone of assumed or known velocity and by using standard time-term equations for layer thicknesses and depths.The treatment covers an arbitrary number of blind zones embedded within a multilayer sequence of horizontal or dipping refractors. Model calculations affirm the benefits of this approach compared with previous methods which, in general, have been restricted to the case of two horizontal layers with one intermediate blind zone.
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    Notes: For a thin highly-conducting layer with given longitudinal conductance the recurrence formulae for an n-fold horizontally stratified subsoil are established for d.c. resistivity and magnetotelluric soundings. Similarly, a thin low conductivity layer with given transverse resistance is treated in the d.c. case and a non-conducting intermediate bed in magnetotellurics. Model curves for a thin high- or low-conductivity intermediate layer in the three-layer case have been carried out, which may serve as an extension of the well-known three-layer diagrams for a Schlumberger configuration. The corresponding model curves in magnetotellurics are given.By numerical comparison of these curves with real three-layer curves some diagrams have been developed to show the allowed thicknesses of the intermediate layer in the Schlumberger case and in the case of magnetotelluric sounding.
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    Notes: Four radar systems at three different frequencies are described which are useful in probing into salt for finding information of interest to miners. Ranges in salt to (a) the edge of a salt dome, (b) the top of the salt dome, (c) boreholes in salt, or (d) faults or hazards ahead of mining can be determined using one or more of these radar systems. Radar wave velocities in salt are determined by radar probing through pillars of known length, and then used to determine ranges in salt to timed radar reflections. Radar probing results are shown obtained in different salt mines probing upwards and downwards. Enclosed areas in the mine are the best radar station locations to probe into salt as air reverberation of radar energy is shortened.
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    Notes: A simple extension of our previous work in which digital filters were developed to transform dipole resistivity measurements over layered earth to Schlumberger ones leads us to the development of filters for transforming the latter to the former. As in the previous work we use a sampling interval of 1/6 In 10 in designing the filters that are both accurate and fast in operation.
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    Notes: Seismic facies analysis makes use of different seismic parameters in order to get other than structural information. A review is given of possibilities and usefulness of seismic facies analysis in oil exploration.A seismic facies unit can be defined as a sedimentary unit which is different from adjacent units in its seismic characteristics. Parameters that should be taken into consideration in the seismic facies analysis are as follows: reflection amplitude, dominant reflection frequency, reflection polarity, interval velocity, reflection continuity, reflection configuration, abundance of reflections, geometry of seismic facies unit, and relationship with other units.Interpretation of seismic facies data may be either direct or indirect. The purpose of the direct interpretation is to find out geological causes responsible for the seismic signature of a seismic facies unit. So, the direct interpretation may be aimed at predicting lithology, fluid content, porosity, relative age, overpressured shales, type of stratification, geometry of the geological body corresponding to the seismic facies unit and its geological setting. The indirect interpretation is intended to reach some conclusions on depositional processes and environments, sediment transport direction, and some aspects of geological evolution (transgression, regression, subsidence, uplift, erosion).The results of the seismic facies analysis may be shown on seismic facies cross-sections and seismic facies maps. Depending on the available seismic data and geological conditions in the area under consideration, the seismic facies maps may be of different types such as general seismic facies maps showing distribution of different seismic facies units, sand-shale ratio maps, direction of cross-bedding and paleo-transport maps etc.Several kinds of seismic facies units and their geological interpretation are discussed as examples of seismic facies analysis.
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    Notes: The reflectivity method for computing synthetic seismograms can be applied to seismic prospecting problems with special focus on coal-mining problems. The method allows the calculation of reflected waves for point-source excitation and non-vertical incidence. It automatically includes all possible conversions of wave types and all inner multiple reflections. Synthetic horizontal- and vertical-component seismogram sections are given for a simple two-seam model and for a realistic seam sequence which is represented by 48 layers; the source-receiver distances range from 100 m to 1000 m. These seismograms show prominent PS reflections already at moderate source-receiver distances. These waves complicate the vertical-component records by producing arrivals of similar strength as the PP reflections. From this it is concluded that PS reflections in strongly layered media can cause problems in routine CDP stacking. On the horizontal-component records the PS reflections are dominant. Because of the lower velocities of S waves the time resolution of PS reflections is better than that of PP reflections. This suggests that horizontal-component recording may be useful in the investigation of subsurface regions with strong velocity contrasts, even with conventional energy sources producing mainly P waves.
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    Notes: Expressions for the I. P. activity coefficient for an inhomogeneous sphere with the conductivity increasing/decreasing from the core towards the periphery according to a power law have been derived.In certain geometrical situations of the electrode configurations a negative I. P. signal is obtained. The negative I. P. may be understood as due to modifications in the discharge current from the polarized medium during the discharge process.The results of the investigation may be useful for more accurate interpretation of I. P. anomalies due to isometric inhomogeneous bodies.
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    Notes: Magneto-telluric experiments were performed in August 1974 in the Muhos Jotnian sedimentary formation and the Koillismaa Precambrian basement complex by the Centre de Recherches Géophysiques, Garchy, and the Department of Geophysics, University of Oulu, employing the “Résistivimètre magnéto-tellurique”, an instrument which permits apparent resistivity values to be observed at eight pre-selected frequencies between 8–1700 Hz.Preliminary soundings were made on the Muhos formation and on its surroundings, after which a magneto-telluric profile was measured involving eleven sites on a line 13 km long extending across the formation. Some further soundings were made at certain sites of known stratigraphy. The resistivity values in the sedimentary formation were found to vary between 10 ωm and 200 ωm, while those in the basement were markedly higher. This resistivity contrast suggests that the method seems to be suitable for delimiting the sedimentary formation.Soundings made on the basement at Koillismaa show apparent resistivity values in the range 1000–20000 ωm. The interpretation of these soundings was in agreement with other, independently obtained geophysical results.
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    Notes: Multispectral recordings used for remote sensing are not without analogy with seismic records from CDP field set-ups. These seismic data may be regarded as “photographs’ of deep regions of the earth taken from various angles.The Karhunen-Loève (K.L.) transformation is commonly used for multispectral data processing, where it helps emphasize some features of remote sensing information. The same method may be applied to seismic data processing. Signal-to-noise ratio is improved on synthetic or field examples when K.L. transformation is applied instead of conventional CDP stacking. Residual statics seem to be diminished by a significant factor.
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    Notes: A horizontally layered non-absorptive system of homogeneous layers may be specified by giving the reflection coefficients at each interface. Provided the layers have equal vertical travel time and a perfect reflector as a free surface, the reflection coefficients are generally reconstructed from the reflected pulses by way of solving simultaneous equations of the Toeplitz matrix form with the Levinson recursion method. There exists an alternative approach to solving this problem which by simple reasoning immediately turns out the (Levinson) recursion scheme. The method is based on formulas that relate to solving the forward problem. It resembles Kunetz's (1962) original inverse solution in as much as the computation of the reflection coefficients is based on the idea of separating the contribution of a primary from the sum of all multiples.
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    Topics: Geosciences , Physics
    Notes: The magneto-telluric and telluric-telluric profiling techniques are presented, and then a new method which combines these two techniques for mapping a parameter defined as the “apparent pseudo-resistivity”.The results obtained for the uranium structures in the Cluff Lake district (Saskatchewan Canada) indicate the use of these different techniques in the detection of zones of conduction for surface zones and for deeper zones, and demonstrate the advantages of these methods over the usual electrical methods in problems of structural research.
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  • 159
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    Topics: Geosciences , Physics
    Notes: The geological sequence rock-coal-rock represents a seismic low-velocity channel. Channel waves generated in a coal seam and their reflections from discontinuities can be used for proving the minability of the seam. To investigate the process of reflection, two-dimensional models of the sequence rock-coal-rock have been investigated by means of the ultrasonic transducer technique. Two-dimensional models have the advantage that the wave field can be observed at an arbitrarily chosen point of the model plate. Thus, by means of these models the direct and the reflected Rayleigh channel wave can be observed along their path of propagation.From the geophysical point of view the various types of discontinuities of a coal seam can be divided into two basic types: one is restricted to the seam, the other includes in addition a fractured zone in the adjoining rock.The investigation of the symmetrical Rayleigh channel wave reflected by a discontinuity yields the following results:For dip angles γ between approximately 90° and approximately 60° the reflectivity is virtually independent of the type of discontinuity. This does not hold for the limiting case of γ= 90° (vertical dip) for which the reflectivity increases with increasing influence of the fractured zone. For dip angles γ between approximately 60° and approximately 40° the reflectivity is still independent of the fractured zone but the shape of the reflected wave deteriorates with increasing influence of the fractured zone.For dip angles γ below approximately 40° the reflected wave deteriorates such that the application of the in-seam seismic reflection method will be difficult or even impossible.The conversion of the direct wave of the symmetrical fundamental mode into a reflected wave of the antisymmetrical fundamental mode has been observed.
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    Topics: Geosciences , Physics
    Notes: Analytical solutions exist for the potential of a Point Source in media with depth dependent conductivity of the form σ(z) =σ0(1 +αz)n.Of particular importance is the case of the linear gradient (n= 1). More general distributions of conductivity with depth can be approximated by equivalent sequences of homogeneous layers. Comparison between such approximations and the analytical solution for media with linear gradient of conductivity indicates that already a coarse step function yields a reasonably good approximation.
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  • 161
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    Grass and forage science 33 (1978), S. 0 
    ISSN: 1365-2494
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: In a field experiment with Italian ryegrass residual effects of N applied in late April at four rates, 28, 84, 140 and 196 kg ha−1, and of different dates of first harvest ranging from 1 to 14 weeks after N application, were studied. The harvests after the first added about 10 kg dry matter yield and about 0.16 kg N yield for each extra kg N applied in April. Residual response was similar for each increment of applied N. A positive residual response to N was obtained in May of the year following N application despite high winter rainfall. N content of herbage during part of the summer was reduced by extra N applied in April although N yield was increased. The reduction in N content was accompanied by a reduction in P and K content, these latter elements having been applied only once and at a uniform rate on all plots. Loss of N, P and K from the crop, when a period of more than about 9 weeks regrowth was allowed prior to the first harvest, was not recouped at subsequent harvests. Residual marginal recovery of N in Aberystwyth was no higher than in comparable experiments in Cambridge although marginal recovery of N at the first harvest had been appreciably lower in Aberystwyth than in Cambridge.
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  • 162
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    Grass and forage science 33 (1978), S. 0 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A mathematical model which simulates a single-cut forage conservation system is described. It was designed to investigate the effect of machine performance on the nutrient content of conserved forage but its scope is much wider, so that the effects of such aspects as crop growth characteristics, climatic differences and management policy can be assessed. An example of the use of the model to determine the value of chemical additives to high moisture content hay is described in detail. Various uses of the model are discussed and some of its limitations are shown to be caused by a lack of data on factors determining dry matter losses.
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  • 163
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Inoculation in the glasshouse revealed marked differences in resistance to both ryegrass mosaic virus (RMV) and crown rust (Puccinia coronata Corda) among eight unselected populations of Italian ryegrass (Lolium multiflorum Lam.). Two generations of selection for crown rust resistance led to a significant improvement in all eight populations, while one generation of selection for RMV gave a more variable response. Frequency distributions of individual genotype scores suggested that much of the resistance to crown rust was under the control of one or two genes with major effects, while resistance to RMV appeared to be controlled by a large number of genes each having a small effect.In the field, resistance to RMV meeisured after 20 months was strongly correlated with that obtained in the glasshouse. Natural infection by crown rust in the field was too low to reveal any differences between populations, although three populations from the Po Valley region of Northern Italy became heavily infected with Puccinia recondita.Selection for disease resistance significantly reduced the persistency of three populations, but that of four others was unaffected and one showed a significant improvement. Selection reduced water-soluble carbohydrate (WSC) levels in spring slightly but significantly from 27.6 to 25.8% WSC overall. These results emphasize that agronomic performance must be monitored during selection for disease resistance.
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  • 164
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: A field investigation was carried out over 3 years to determine if there was a synergistic effect on total or seasonal yield when cultivars of perennial ryegrass were grown in combination.The three cultivars used were Stormont Zephyr, Hora and Perma, representing respectively early, medium late and late maturing groups. Each cultivar was grown as a pure stand and also as a 50:50 mixture with each of the other two cultivars. Each of these swards was maintained under two rates of nitrogen fertilization (300 and 600 kg per ha per annum) and under two harvesting treatments (4 and 8 harvests per annum).Mixture yield did not exceed significantly the pure sward yieid of the highest yielding component. Occasional yield improvements were detected for the mixtures averaged as a group over monocultures averaged as a group. There was a tendency, especially under frequent cutting, for the yield response to nitrogen to be greater from mixed than from pure swards.
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  • 165
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Persistence assessments on eight mid-season and ten late cultivars of perennial ryegrass were made at the end of the second, third and fourth years after sowing. Botanical analyses were carried out on the herbage from plots cut in the fourth year and these results related lo the different persistence assessments. It was found that persistence assessments carried out at the end of the second year enabled predictions to be made about botanical composition of cuitivars in the fourth year. Little extra precision was gained by delaying assessment until the third or fourth years as the ranking order of cultivars with respect to persistence remained largely unchanged. All persistence assessments were positively correlated with yields of sown cultivars and negatively correlated with yields of unsown herbage species in the fourth year. However, only low correlation coefficients were obtained between persistence assessments and the total yield of sown cultivar and unsown species in the fourth year, due to yield substitution between these two components.In swards sown as monocultures low persistence in a cultivar is considered to be a lack of perenniality and tiller regeneration rather than poor competitive ability against volunteer species though in mixed swards competitive ability per se will have considerable influence upon the changes in botanical composition under different managements. Persistence and yield capacity are seen, however, as distinct characteristics of a cuitivar and long-term yield potential is a joint function of these characteristics.
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  • 166
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The effects of applying nitrogen at different growth stages to S24 and S23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1971 to 1976. These varieties of ryegrass were found to be insensitive to timing of nitrogen application from apex initiation to the stage when ears first emerged. However, if nitrogen application was delayed until about 30% or more of the ears had emerged, yields were lower compared with earlier applications, this effect being significant when nitrogen was delayed until 70–80% ear emergence because of a decrease in both numbers of fertile tillers and number of seeds per unit area. No advantages were found for splitting nitrogen applications between apex initiation and ear emergence.
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  • 167
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Oven- and freeze-dried samples of the separated green material of Trichophorum caespitosum, Molinia caerulea, Eriophorum vaginatum, Erio-phorum angustifolium, Juncus acutiflorus and J. squarrosus collected in May, July and September were analysed for dry matter digestibility (DMD) using an in vitro procedure and for structural carbohydrate content.Results were affected by method of drying, oven-dried (45°C) samples in general giving lower estimates of quality than freeze-dried samples. Low DMD values were obtained for J. squarrosus for all sampling dates. The remaining species had DMD values above 60 in May; some maintained these levels until July but all had low values by September.A comparison was made between in vitro DMD and predicted DMD using the data from the structural carbohydrate analyses and the summative equation of Van Soest (1965a). Two species, J. acutiflorus and J. squarrosus, showed poor agreement between values obtained by the two methods. The other species showed good agreement between values in May and July but poor agreement in September.The data are discussed in relation to the quality and seasonal patterns of growth of species of hill vegetation.
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  • 168
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: In two 4 × 4 Latin Square experiments, one with dry cows and one with sheep, animals were given ad libitum early-cut ryegrass silages prepared using formic acid (2.31 t−1) as an additive. The silages were offered either untreated or partially neutralized with either a low (8 g kg−1 fresh weight) or high (16 g kg−1) level of sodium bicarbonate or with sodium bicarbonate solution (50 g kg−1) given as an intraruminal infusion at a rate sufficient to provide bicarbonate at a rate similar to that provided by the high level of dietary addition.In cows the bicarbonate treatments were associated with a depression in the intake of organic matter which at the high level of addition of bicarbonate was statistically significant (P 〈 0.05). In sheep the bicarbonate treatments were associated with a slight increase in the intake of organic matter but the efFects were non-significant (P 〉 0.05). In both species water intake increased directly with the quantity of bicarbonate ingested.In both experiments the bicarbonate treatments increased rumen pH but there were no significant treatment effects on the concentration of ammonia or of total or individual short-chain fatty acids in the rumen fluid. In sheep, bicarbonate addition or infusion had no effect on the digestibility of organic matter but at the high levels of bicarbonate supplementation there was a tendency for the digestibility of nitrogen to be depressed.In two further experiments each with two dry cows determinations were made of the effects on food intake of (a) the insertion of water-filled bags into the rumen and (b) the removal of digesta from the rumen. Treatment (a) produced consistent and significant (P 〈 0.05) depressions in dry matter intake and treatment (b) increased (P 〈 0.05) dry matter intake in one cow but not in the other.The lack of significant improvement in silage intake through the addition of sodium bicarbonate to the diet indicated that the acidity of the silage was not a major factor limiting appetite. On the other hand, the effects of the insertion of water-filled bags into the rumen and of the removal of digesta from the rumen on feed intake were consistent with appetite being controlled through a rumen-fill mechanism.
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    Notes: Moisture and mineral concentrations and calorific values of cattle dung pats were studied under field conditions. The rate of moisture loss from dung pats varied according to the season but the dung was rarely re-wetted by rainfall. Soluble mineral ions were only leached from pats by prolonged rainfall. Magnesium was particularly resistant to leaching. In the summer months about 15% of the organic matter in the dung was lost over 2 months. The calorific value of the dung decreased by 18% in the same period. The loss of organic matter resulted in a concentration effect in calcium, iron, magnesium and nitrogen.
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  • 170
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    Notes: The regrowth of Italian ryegrass was studied at weekly intervals from 2 to 14 weeks after a cut in late April when 140 kg ha-1 N was applied. Reduction in digestibility with delay in date of harvest was due to both an increase in the proportion of cell wall and a reduction in the digestibility of the cell wall, particularly the former from week 2 to about week 5 and particularly the latter after week 5. The reduction in the digestibility of the cell wall was about equally attributable to reduction in digestibility of cellulose and to reduction in digestibility of hemicellulose. The proportion of lignin in cell wall was highly correlated with both digestibility of cellulose and digestibility of hemicellulose. The proportion of digestible cell wall in dry matter was not as constant as has sometimes been noted, increasing by about 5 percentage units from week 2 to week 5 and decreasing by about 10 percentage units from week 5 to week 13. During the latter period the decline in digestible cell wall in dry matter accounted for nearly half the decline in true digestibility of dry matter. The ratio of cellulose:hemicellulose averaged 1:0.89 and hemicellulose was more digestible than cellulose. Rate of increase in yield of cell contents appeared to diminish from about the third week of regrowth onwards, whereas the rate of increase in yield of dry matter did not begin to diminish until about the seventh week. In vitro dry matter digestibility was not increased by adding extra N to the digestion tubes, even with samples containing only 1% N in dry matter.
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    Notes: A reproducible method of causing tiller death on individual ryegrass (Lolium perenne L., cv. S23) plants is described. This was achieved by subjecting whole plants grown previously for 7 weeks in full light (100%) and full nutrient (100%) to either light stress (17.5% or 2.5%) or nutrient stress (10% or 0%) or various combinations of light and nutrient stress. Detailed records were made of tiller appearance, position and weight, and the probability of tiller death was calculated. Analysis of each plant indicated that the smallest tiller, which was often, but not always the youngest, was the most vulnerable when the whole plant was stressed. Tiller position was relatively unimportant in determining survival. The results are discussed in relation to tiller mortality in natural populations and crop communities.
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    Notes: Book reviewed in This Article: Protein and Non-protein Nitrogen for Ruminants By various authors Green Crop Fractionation Occasional Symposium No. 9, British Grassland Society Edited by R. J. Wilkins Soil Organisms as Components of Ecosystems Proceedings of the Sixth International Soil Zoology Colloquium, Uppsala, 21–25 June 1976 Ecological Bulletins No. 25 Edited by U. Lohm and T. Persson
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The causes of tiller death in a 2-year-old perennial ryegrass sward were examined between April and August 1977. Physiological causes accounted for most tiller deaths and grazing by slugs and rodents was more important than the damage caused by stem-boring larvae. Tillers which died were mainly small and vegetative, although some flowering tillers died prematurely. Low nutrient status delayed but did not prevent tiller death.Using 14CO2 it was shown that small tillers fixed relatively less radiocarbon than did larger tillers and they did not receive much support for their carbon economy. Selective defoliation showed that in April defoliated tillers imported radiocarbon from undefoliated tillers but that in July at anthesis an undefoliated reproductive tiller retained most of the carbon it fixed, despite its vascular association with defoliated tillers. It appears that much of the tiller death during the period April-August is due to the failure of the more favourably placed tillers to support other tillers which are heavily shaded.
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  • 174
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    Notes: Five experiments were conducted to determine the effect of pre-harvest treatment with steam or formic acid on the moisture concentration (MC) in crops of lucerne, two varieties of perennial ryegrass, tall fescue and Italian ryegrass. In each experiment, plots were treated with a mixture of hot gases and steam (S) or sprayed with an aqueous solution of formic acid (F). In the tall fescue experiment the F treatment was applied to the cut swath but in all other instances the F and S treatments were applied to the swards before cutting and the MC changes after treatment compared with those in untreated cut swaths (W 1). Twenty-four hours after initial treatment all S plots, and those F plots other than tall fescue, were cut and the subsequent water loss compared with that from (i) untreated material cut at the same time (W 2) and (ii) the W 1 plots cut the previous day.In all five experiments the change in the MC of the S plots was similar to that of the W 1 plots both before and after cutting. The reduction in the MC of the F plots before cutting was less than that of the S and W 1 plots, and in three of the five experiments water loss from cut F plots was apparently restricted in comparison with that from untreated cut material (W2).Neither desiccant treatment showed great promise as a pre-treatment to cutting for hay making although formic acid may have limited value when a crop is to be harvested directly for silage or artificial dehydration.In an appendix, the efficacy of using accumulated vapour pressure deficit as a basis for comparing the water loss from the untreated cut crops drying under different conditions is demonstrated.
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    Notes: Storage losses in moist hay treated with propionic acid were compared with those occurring in untreated moist hay in two experiments and with field-cured hay in three experiments. Dry matter losses in treated hays ranged from 41 to 8.6% and from 1.7 to 12.6% in untreated hays. Digestible organic matter losses in both treated and untreated hays were generally greater than dry matter losses. Only in one experiment did propionic acid application significantly reduce nutrient losses in moist hays.Nutrient losses, and water-soluble carbohydrate losses in particular, were shown to be correlated with maximum and cumulative bale temperatures during storage in two of the experiments. The rise in hale temperatures during storage was reduced in all three experiments, to a greater or lesser extent, by application of the additive.Loss of propionic acid from the hay during and after application was very large. In the three experiments 86.2, 85.3 and 85.6% of the acid applied was lost by the end of the storage period. Acid distribution studies indicated that variation in acid concentration within bales was as great as between bales. It was concluded that more research is needed into applicator design and position on the baler and into alternative application methods if the benefits of propionic acid as a moist hay preservative are to be fully exploited.
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    Notes: The resistance often early, ten medium late and ten late flowering ryegrass populations to two rates of dalapon (2.8 and 5.6 kg ha-1 acid equivalent) was measured in a box experiment. There was no difference in the mean effect of dalapon on the maturity groups at the time of greatest yield reduction, but the recovery of the late flowering population was, on average, better than that of the medium late group. There was a range of reaction to herbicide within all three maturity groups and, in general, the high yielding populations without dalapon were the most resistant, but there were exceptions. Assessment at 2.8 kg ha-1 acid equivalent gave a similar ranking order to that using twice the amount of dalapon. The results of the current box experiment with seedlings were consistent with those obtained in the field at another location (Faulkner, 1974) for the eleven cultivars common to both trials. The resistance of a permanent pasture population was much lower than that of some cuttivars.
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    Notes: Two contrasting Gremie perennial ryegrass and Blanca white clover seeds mixtures were established. Each sward type was either continuously or rotationally (four paddocks) grazed at two stocking rates by lambs of 26–28 kg initial mean live weight in two 12-week experiments. Dry matter production, assessed by the cage method, was lower on the high-clover sward during the first experiment but overall was similar between seeds mixtures. Clover content, and differences between sward types, declined with time and was lowered by continuous grazing in both experiments and by the higher stocking rate in the first experiment.Animal performance was related to intake and both were increased by lowering stocking rate, increasing clover content and adopting a continuous grazing system. The results are discussed in relation to the experimental methods used and to other published findings.
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Four Italian ryegrass varieties of different origins and winter hardiness were grown as spaced plants at a lowland and an upland site and subjected to ten managements comprising two nitrogen levels and five autumn cutting treatments. Tiller mortality after the winter of 1971–72 was measured in March and subsequent spring recovery from winter damage in April.Although the winter was not severe, there was considerable winter kill, particularly at the upland site where the most severe treatment combinations killed up to 90% of the plants of the more susceptible varieties. In general, winter kill was increased by raising the level of nitrogen fertilizer and by late or frequent autumn defoliations, and significant interactions between locations and the two treatment factors emphasized the importance of the siting of the experiment.The varieties difFered in their overall winter hardiness, with Bb 1430 and RvP suffering less tiller mortality than S22 and Grasslands Paroa in all the treatment combinations, but significant interactions of varieties with locations and cutting treatments revealed that the magnitude of the difference between varieties varied with location and cutting management. Regression analysis of these interactions, however, showed that the tiller mortality of all four varieties increased linearly with the increasing stresses applied by the location × management combinations. There was no differential variety recovery from winter kill, the spring yields being entirely related to the level of tiller mortality experienced.These results are discussed in relation to the breeding of winter hardy varieties, the choice of variety and autumn management practice.
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  • 180
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    Grass and forage science 33 (1978), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Two experiments were conducted with sheep to investigate the effect of silage chop length on voluntary intake and eating and ruminating behaviour. The silages, made from Italian rye-grass, either received no additive or formic acid at a rate of 4 g kg−1 and were chopped to lengths of 5.3 cm (long), 1.8 cm (short) before ensiling or 1.8 cm (long/short) before feeding. The addition of the additive and short chopping improved the fermentation characteristics of the silage. Voluntary intake of silage dry matter and organic matter was higher with the short than with the long silage. Differences in silage digestibilities and cellulolytic activity did not explain the increase in silage intake. Sheep on the long silage had a lower rate of intake and a shorter ruminating time than on short silage, and thus the effective breakdown of the silage in the rumen was delayed, i.e. an increased latency time. Pseudo-rumination was significantly higher on the long than on the short silage.
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  • 181
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    Grass and forage science 33 (1978), S. 0 
    ISSN: 1365-2494
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: In two experiments conducted with Ayrshire dairy cows in 1974 and 1975 on swards of S23 perennial ryegrass, four systems of continuous grazing were investigated. The leys received 345 and 370 kg ha-1 fertilizer nitrogen in 1974 and 1975 respectively and were stocked at the rate of five cows per ha. In 1974, a comparison was made between two systems which either integrated silage making with, or separated it from, the continuous grazing. The provision of a silage aftermath in late July increased milk yield after that time, but had no significant effect on milk yield over the 19-week experimental period. In 1975, a comparison between weekly and monthly applications of fertilizer N showed no significant differences between milk yields in a 20-week period. The feeding of supplementary concentrates from late July onwards significantly increased milk yield. The treatments in both years had only small and mainly non-significant effects on milk composition. On average, excluding the concentrate treatment, the annual output of milk was 10,800 kg ha-1 using spring-calved cows.
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    Grass and forage science 33 (1978), S. 0 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 183
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    Grass and forage science 33 (1978), S. 0 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Book reviewed in This Article: Green Crop Fractionation: an Economic Analysis by R. J. Wilkins, S. B. Heath, W. P. Roberts, P. R. Foxell and A. Windram.
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  • 184
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    Grass and forage science 33 (1978), S. 0 
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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  • 185
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    Grass and forage science 33 (1978), S. 0 
    ISSN: 1365-2494
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    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Maize silages made in October were fed to forty-three autumn-calving cows during a 20-week winter feeding trial. The control silage received no additive whereas a non-protein nitrogen (NPN) additive was applied to the other silage at harvest time. The four experimental feeding treatments were: A, maize silage + 6 kg d−1 barley; B, maize silage with NPN + 6 kg d−1 barley; C, maize silage + 5 kg d−1’barley + 1 kg d−1 extracted decorticated groundnut cake; D, maize silage with NPN. The mean daily milk yields of cows on the treatments were 14.7, 15.1, 15.3 and 15.0 kg respectively. All cows received maize silage ad libitum. There were no significant differences in milk yield but the milk produced by the cows on treatment D had significantly lower concentrations of milk fat, protein and solids-not-fat when compared to the other three treatments. The cows on treatment D had a negative liveweight change which was significantly different (P 〈 0.05) from those of the cows on treatments B and C.
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  • 186
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    Geophysical prospecting 26 (1978), S. 0 
    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: The use of arrays to separate primary reflections from unwanted coherent seismic events is common practice in land seismic surveys. Very long source and receiver arrays have been used recently to reduce the effects of waterbottom multiples on marine seismic data.The source array consists of five uniformly spaced identical subarrays, each with five different airguns, where the distance between the subarrays may vary from 20 m56 m. The volume of each subarray is 10.3 1 (630 cu.in.) which gives a total volume of the array of 51.5 1 (3150 cu.in.) operated at a pressure of 14 MPa (2000 psi). In order to have a flexible receiver system it was decided to implement the extended receiver array in data processing by computing a weighted sum of two to five traces. The hydrophone cable consists of fifty-four channels with a group length of 50 m.Data shot with the superlong airgun array are processed by a combination of standard techniques and special procedures. In particular, the quality of the stack section is improved by using a weighted stack. The stack weights are computed by a program which takes into account the primary-to-multiple ratio.Comparisons with conventional data show significant improvements in data quality obtained by using the superlong airgun array. Examples show that the waterbottom multiples have been strongly attenuated and the deep seismic events have been enhanced.The combined array response function for dipping events is given in an appendix.
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  • 187
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    Topics: Geosciences , Physics
    Notes: We start from the Hankel transform of Stefanescu's integral written in the convolutionintegral form suggested by Ghosh (1971). In this way it is possible to obtain the kernel function by the linear electric filter theory. Ghosh worked out the sets of filter coefficients in frequency domain and showed the very low content of high frequencies of apparent resistivity curves.Vertical soundings in the field measure a series of apparent resistivity values at a constant increment Δx of the logarithm of electrode spacing. Without loss of information we obtain the filter coefficient series by digital convolution of the Bessel function of exponential argument with sine function of the appropriate argument. With a series of forty-one values we obtain the kernel functions from the resistivity curves to an accuracy of better than 0.5%. With the digital method it is possible to calculate easily the filter coefficients for any electrode arrangement and any cut-off frequency.
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  • 188
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    ISSN: 1365-2478
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Physics
    Notes: Most of the data recorded at seismological observatories are essentially noise, not signal. One way to achieve a higher information density is to trigger the seismograph, as in strong-motion accelerographs. This approach loses the first motion—not important for earthquake-engineering studies, but very important for studies of focal mechanism. To eliminate this defect, various cumbersome techniques have been used, such as closed-loop tape-recording.Here we describe a seismograph that records only the signals and does not lose the first motion. Our procedure uses a microprocessor (MC6800) to monitor the energy level adaptively, uses a solid-state memory like a large shift-register, and has the microprocessor trigger recording from the solid-state memory onto a tape cassette whenever a signal (as defined by energy level) is recognized by the microprocessor.A field station consists of a crystal clock, seismometer, amplifier, analog-to-digital converter, Parallel Interface Adapter (PIA), MC6800 microprocessor, 8K solid-state memory, Asynchronous Communications Interface Adapter (ACIA), cassette tape-recorder, and battery. The duration of operation depends upon the frequency content of data, the sampling rate used, and the frequency of events. The design criteria used for the stations of the first field system are a 1 Hz to 10 Hz bandpass amplifier, 8-bit digitization, 5 samples per cycle of highest frequency content, and quality tape cassettes. These requirements are appropriate for exploring for magma chambers in subduction zones—the motivation for developing this system. A playback facility uses the DEC LSI-11 computer, which has an assembly language set very similar to that of the MC6800.This equipment, or a slight modification thereof, would be suitable for recording strong-motion earthquakes, for monitoring quarry blasts, or for any seismological effort in which the triggering criterion can be specified as an algorithm for programming into the microprocessor firmware. The resulting data are digital and only include significant signals, thus the data reduction facilities may properly concentrate on analysis and interpretation. Because the parameters of the system can be easily modified in firmware or software, the system is very flexible and can be considered the Universal Geophysical Recorder. An adaptation to recording transient EM phenomena is in progress. In this application, the source is controlled, but the use of the self-triggering approach eliminates the need for a radio-control system to activate the recorders, HIG Contribution no. 753.
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  • 189
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    Geophysical prospecting 26 (1978), S. 0 
    ISSN: 1365-2478
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    Topics: Geosciences , Physics
    Notes: The problem of detecting discontinuities which interrupt coal seams is of great importance to the coal mining industry. One possible method of detecting such discontinuities is that of in-seam seismology where both source and detectors are placed under- ground on the coal face. In this paper the propagation of SH waves from a line source in the seam is investigated. There exists a particular set of waves–channel waves–, confined to the coal seam. These waves are dispersive and have an associated Airy phase whose geometrical attenuation is least. However, if absorption of energy within the coal is included then the Airy phase is the dominant wavegroup only for distances less than a certain maximum. If a detection criterion proposed by Dresen and Freystätter applies, then there is a lower limit to the frequency that should be used for exploration. This requirement may be in conflict with attenuation considerations.
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  • 190
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    Geophysical prospecting 26 (1978), S. 0 
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    Topics: Geosciences , Physics
    Notes: Reflections and refractions from curved interfaces were studied on two dimensional scale models. Time of arrival, amplitude and character of reflected, converted, and refracted waves were mainly used for this study. Some reflected refractions, refracted reflections and diffractions were also considered. It was possible to separate PS and SP waves and to study their amplitude and character separately. From the amplitude study of refracted arrivals it was concluded that the refracted ray path penetrates into the high velocity layer rather than propagating along the interface. Although most of the results are interesting from the theoretical point of view, a few applications to exploration problems are suggested.
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  • 191
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    Geophysical prospecting 26 (1978), S. 0 
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    Topics: Geosciences , Physics
    Notes: The results of specific processing of seismic sections on an actual oil field have proved that it is possible to find a link between a seismic parameter (amplitude of a reflecting horizon) and petrophysical characteristics of a reservoir whose changes modify well productivity.A good correlation appears between the values of good oil productivity and the weakness of the amplitudes of one horizon close to the oil producing layers.
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    Geophysical prospecting 26 (1978), S. 0 
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    Topics: Geosciences , Physics
    Notes: The expressions for quasi-static electromagnetic fields of a horizontal electrical dipole placed on the surface of a polarizable half-space have been derived for low and high values of induced polarization parameter and presented along with numerical results. It has been observed that the polarity of the mutual impedance function is negative for low values and positive for high values of the induced polarization parameter in the entire time domain, whereas the induced voltage function is positive for low values of induced polarization parameter and becomes negative for high values. In the case of low values of induced polarization parameter the transient electromagnetic field in the beginning increases with time, later on it starts to decay with time. The present study shows that the decay rate of electromagnetic field is highly dependent upon the induced polarization parameter. In the light of the present study the conductivity of the polarizable medium may be determined more accurately.
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    Topics: Geosciences , Physics
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    Geophysical prospecting 26 (1978), S. 0 
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    Topics: Geosciences , Physics
    Notes: Stratigraphic models are usually oversimplified by petroleum geologists, and the result is that the principles which we use for interpreting geophysical data are also over-simplified or even incorrect.Based on the marine seismic data from the Adriatic Sea, an example of prediction of a rather complex sedimentation model of detrital sediments is shown. On the basis of the stratigraphic interpretation using seismic techniques only for this some very important characteristics are discussed:— paleotopography of the valley and conditions which have given opportunity to map accurately the pre-depositional surface,— seismic signatures of the sedimentary section of the ancient valley in which we have recognized aluvial sequence and marine one.The conclusion is that there is a real opportunity for exploration of stratigraphic traps in this part of the Mediterranean Basin.
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  • 195
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    Geophysical prospecting 26 (1978), S. 0 
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    Topics: Geosciences , Physics
    Notes: Boreholes present a potential hazard to mining in rock salt mines. The only rock salt mine in England was almost lost when they mined into an unknown borehole open to an aquifer. Rock salt is a good transmitter of VHF radar waves, so a good method of detecting boreholes is by using radar probing. This paper investigates theoretically the detection of a borehole in advance of mining using two different radar systems, Bravo II and Charlie II. Bravo II has a peak power of 20 kW at 230 MHz and Charlie II has 3 W at 440 MHz. The borehole detectability depends critically on the radar wave attenuation in salt, which is characterized by its loss tangent, tan δ. The backscattering cross section σ of the borehole is also important. These parameters are related in the radar signal-to-noise equation which determines the signal-to-noise ratio (S/N) for a given range in salt to the borehole. Theoretically, in salt with a tan δ of 10-3, Charlie II can detect (S/N= 3 dB) a 12.7 cm borehole 225 m in advance of mining while Bravo II, using only 100 W, can detect the same borehole 680 m ahead. These values are with the antenna E field parallel to the axis of the borehole. Theory shows this antenna orientation to be optimum for maximum detection probability. For salt with a tan δ of 2 × 10-5, the smallest value measured for salt, Bravo II can detect the borehole up to 15.3 km using maximum power of 20 kW.
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    Topics: Geosciences , Physics
    Notes: The electromagnetic surface detection of underground quarries by classical methods becomes difficult when they are situated at depths greater than ten meters and when the thickness and conductivity of the superficial layers are irregular.The problem is tackled in two stages: at first using successive approximations, characteristics of the miscellaneous layers of a stratified medium are identified, and the quarries are then detected by observation of the conductivity changes of one of the lower layers. Computer interpretation, however, is necessary.The chances of detection of the quarries are considerably improved by a field localization method developed by us: computer interpretation is eliminated. The new aspect is an auxiliary transmitter which annuls the currents induced by the principal transmitter in the uppermost—generally more conductive—layers.The theoretical and experimental results show that the probability of detection of the quarries by this method are four times as high as by the classical one.
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    Topics: Geosciences , Physics
    Notes: This final part of our study of the resistivity sounding method in the presence of transitional layers deals with the direct application of the theoretical developments, previously reported, to both theoretical and field examples. The former are used to explain in more detail all steps of the direct procedure of interpreting resistivity measurements, when transitional layers with different dispositions are present in the assumed earth section. An alternate sequence of uniform and transitional layers is at first considered, then the case of a random sequence of these layers, and finally a sequence of only transitional layers. Then we give some logical considerations about the best fields of application of the new interpretation theory, with particular reference to hydrogeological, geological- structural, and mining exploration problems. Representative field examples are finally presented and discussed in detail for each of the exploration fields above listed. The comparison of the geophysical models obtained with the old interpretative scheme and the new system shows the greater resolving power of the new theory, provided that preliminary geological considerations, and where existing–borehole evidence justify the use of the new approach.
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    Topics: Geosciences , Physics
    Notes: During the last few years many airgun arrays have been designed with the objective of generating a short signature of high amplitude. For linear arrays of non-interacting airguns two rules have been derived that may help in the design or evaluation of airgun arrays. To achieve a short pressure pulse, the total available air volume has to be distributed over the individual guns in such a way that the tail of the signal, owing to the added bubble signals, becomes as flat as possible.When we think of ordering airguns according to volume, this flat signal tail can be achieved by designing the volumes such that the difference in bubble times of two adjacent guns is proportional to their volume to the power 2/3.The amplitude expected from a linear array of non-interacting airguns is limited by the physical length of the array.A graph of measured values tends to confirm this relation.No relation has been found between the total volume of an array and its amplitude.The graph also detects inefficient use of available array length of existing arrays.
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