ALBERT

Notizen: The growth inhibition of Tetrahymena furgasoni (once known as “T. pyriformis W”) by C19 and C21 steroids of similar structure was measured by determining cell population at 24 h and 48 h following addition of the steroid. A cis-fusion of the A/B rings junction, unsaturation at C-1,2, or C-4,5 and carbonyl substitution all enhanced inhibition, whereas the presence of two hydroxyl groups decreased inhibition. The results indicated that the transformation of C19 and C21 steroids by this protozoon may be part of a detoxication mechanism.

Notizen: The metabolism of phospholipids in synchronous Plasmodium falciparum-infected erythrocytes was studied over one cycle of 48 h by the incorporation of labeled palmitate, serine, choline, and myo-inositol into cellular lipids. The rates of incorporation of palmitate and serine into total phospholipids and of choline into phosphatidylcholine (PC) were linear with the maturation of the parasite, increasing by a factor of 2–5.6 according to the precursors. The rate of inositol incorporation into phosphatidylinositol was 9.6 times higher at the schizont stage than at the ring stage, with a marked increase in the second half of the cycle. A significant incorporation of palmitate into triglycerides also occurred during the schizont stage of the parasite. The incorporations of serine and palmitate into phosphatidylethanolamine (PE) and PC showed a net increase at approximately the twentieth hour of the cycle, while the radioactivities recovered in phosphatidylserine (PS) had already reached a maximum by this time. These findings indicate an instantaneous transformation of PS into PE and PC through a decarboxylation of PS into PE, then a methylation of PE into PC during the second half of the cycle. Although PS is a minor component of the Plasmodium parasite, our findings demonstrate the important role of this phospholipid as a precursor of PE and PC, which are major constituents of parasite phospholipids.

Notizen: With the aid of energy-dispersive X-ray microanalysis, several protozoa were tested for content of cations within inorganic minerals. The skeleton of acantharia consists mainly of Sr with small quantities of Ca and Ba. Two Loxodes species contain nothing but Ba, while in some Remanella species Sr with small quantities of Ba were present. In one Geleia species, Ca with small quantities of Sr was found; in two Trachelocerca species from Sylt (Germany), Ba is there in addition. Another Trachelocerca species from northern Italy lacked Ba, but did possess Mn. In Prorodon only Ca was found.

Notizen: Thin-sectioning and freeze-etching electron microscopy were applied to explore the structure and the temperature- and Ca2+-response of the different host and parasite membranes during intraerythrocytic development of Plasmodium knowlesi in Macacca mulatta. The plasma membrane of uninfected erythrocytes is temperature- and Ca2+-responsive: chilling to 4°C and exposure to 5 mM Ca2+ induces a slight decrease in IMP-frequency and the emergence of small IMP-devoid patches on P-faces. On parasite infection, the erythrocyte membrane becomes modified as indicated by an enhanced temperature-response and the appearance of caveolae, ca. 70–90 nm in diameter. The frequency of these caveolae is increased in schizont-infected erythrocytes. Moreover, electron dense plaques, ca. 40 nm in width, appear just beneath the erythrocyte membrane in late trophozoites and schizonts, thus indicating a further modification of the host cell membrane during parasite development. The membrane of the parasitophorous vacuole, derived from the host plasma membrane, dramatically reduces the IMP-frequency especially on the P-face upon parasite infection. This leads to an apparent reversal of the IMP-distribution persisting throughout the whole infection cycle. The parasite plasma membrane forms local compaction domains with the nuclear envelope in ca. 30% of the ring-stages and trophozoites, which disappear in late trophozoites and schizonts. Moreover, the IMP-frequency on plasma membrane fracture faces almost doubles during parasite development. Chilling induces a decrease in the IMP-frequency on P-faces of the plasma membrane. Surprisingly, however, the parasite plasma membrane and the vacuolar membrane respond to externally applied Ca2+ with almost a doubling of the IMP-frequency. The different parasite endomembranes also undergo characteristic changes during parasite development.

Notizen: The leech Calliobdella vivida (Verrill) is the vector of Trypanoplasma bullocki. At 10°C, infective-stage flagellates were first present in the leech's proboscis sheath five days after feeding. At 5°C, infective-stage flagellates were not present in the leech's proboscis sheath until 10 days after feeding, but at 20°C, flagellates were located there as early as 24 h after feeding. Infected leeches retained flagellates through three subsequent feeds on uninfected fish. When flagellates were first observed in hogchoker, Trinectes maculatus (Bloch & Schneider), they were much larger than infective stages from the leech. Average flagellate length then decreased during early acute phase, but gradually increased thereafter. Peak parasitemia was greater in a hogchoker inoculated by only one leech but held at colder temperature than in a hogchoker inoculated by 45 leeches, suggesting that temperature may be more important than inoculum in determining peak parasitemia. Cell division in the fish host is described. SEM studies of fish blood flagellates revealed a pre-oral ridge and a cytostome.

Notizen: Histones were prepared from chromatin of the eukaryotic (endosymbiont) nucleus of Peridinium balticum (Levander) Lemmermann. The amino acid composition of whole histone was rich in lysine and similar to that of Olisthodiscus luteus and Euglena gracilis. Electropheretic analysis of these proteins in acidic-urea disc gels revealed four major bands: one with a mobility slightly lower than that of calf thymus HI; and three others which comigrated with calf H2B, H2A, and H4, respectively. The low mobility band was soluble in 5% perchloric acid and was sensitive to FeCl3 destaining. Electrophoresis in slab gels containing 0.1% SDS revealed five major components, with approximate molecular weights of 23,000, 20,000, 15,000, 13,000, and 11,000, respectively. The 15,000 and 11,000 dalton histones had mobilities identical to those of calf H3 and H4, respectively. The two highest molecular weight components were soluble in 5% perchloric acid. No bands were found to comigrate with calf H2A or H2B but a band was present that migrated to a position intermediate between calf H2A and H4 (13,000 dalton histone). Two-dimensional gels consisting of acidic-urea gels in the first dimension and SDS gels in the second dimension revealed that the 20,000 dalton component and the 13,000 dalton component are not resolved in the acidic-urea gel. As a working hypothesis, it is suggested that two of the five bands seen in SDS gels represent an H1-like doublet, and two are analagous to H3 and H4, respectively. The remaining histone may replace H2A and H2B.

Notizen: The iodinating reagent 1,3,4,6,-tetrachloro-3α,6α-diphenylglycoluril (IODOGEN3) was used to label antigens on zygotes of Plasmodium gallinaceum with parallel studies using lactoperoxidase-catalyzed radioiodination for comparison. Proteins labeled by the IODOGEN method are most probably on the surface of the zygote, as the pattern of labeled proteins analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis was very similar to the pattern of lactoperoxidase-labeled proteins. Furthermore, the labeled proteins represented only a subset of the total Coomassie Blue-stained proteins. The radioiodinated zygote proteins were immuno-reactive after IODOGEN or lactoperoxidase labeling. The IODOGEN method is technically much more simple than the lactoperoxidase method and does not require the addition of extraneous proteins or H2O2. The advantages of IODOGEN labeling, together with the essential equivalence of results obtained by these two, methods, make the IODOGEN method attractive for labeling parasite antigens in general.

Notizen: A new method is described for mass cultivation of Euplotes aediculatus, a hypotrich ciliate containing omikron-symbionts. The ciliate cultures, continuously aerated in Erlenmeyer flasks (5000 ml) with 4500 ml medium, yield densities of 2300 cells/ml which are four to five times higher than cell densities of cultures grown in unaerated Fernbach flasks. Harvesting such cultures involves the application of 25-μm mesh sieves. Cells so concentrated can be purified by using columns or special chambers in which Euplotes migrates towards the cathodes in an electric field (field strength 7 V/cm).

Notizen: Stocks of Entamoeba histolytica grown in a monoxenic culture system from the feces of nonhuman primates are compared with the eleven zymodemes of E. histolytica so far demonstrated from man. In a similar fashion, Entamoeba chattoni has also been grown and identified. Both E. histolytica and E. chattoni have been demonstrated in keepers of the primate collections. Comparisons have been made using the electrophoretic patterns of three enzymes: glucosephosphate isomerase [(GPI) E.C.5.3.1.9], phosphoglucomutase [(PGM) E.C.2.7.5.1], and L-malate—NADP+ oxidoreductase (oxaloacetate-decarboxylating) [(ME) E.C. 1.1.1.40]. Enzyme patterns of E. histolytica from the apes were found to be identical with three of those already demonstrated from man. The enzyme pattern of E. chattoni was distinctly different from that of any of the E. histolytica zymodemes. Other protozoa found in the single fecal sample examined from each subject are also listed.

Notizen: . Freeze-cleave replicas of encysted cells of the myxamoebae of Physarum polycephalum were examined to determine the intrawall substructure and to compare the intramembrane structural components. Cleaved areas of the cyst wall revealed a laminated substructure devoid of the macromolecular interruptions (intramembrane particles or IMP) visible in the cleaved cell membranes. The cyst wall adjacent to the cell membrane appears laminated, and a loose branching network of fibers and fibrils occurs at the wall periphery. The absence of intrawall particles is interpreted as a lack of protein or polypeptide components, thus suggesting additional support for the conclusion that polysaccharides are the major wall constituents. When cleaved cell membranes of encysted cells were examined, more intramembrane particles per unit area were observed on the extracellular membrane leaflet than on the protoplasmic membrane leaflet. In addition, homogeneous as well as aggregated particle distributions were visible on cleaved membrane leaflets. Moreover, the presence of aggregated and unaggregated particles on the same membrane leaflets similarly suggests asynchrony of the cell population. This paper examines and compares biological processes involving the cell membrane that may be related to different stages in the cell cycle or to periods of temporary stasis during the cell cycle.

Notizen: . The multiplication rate of “wild-type” (WT) populations of Acanthamoeba castellanii was inhibited 50% by ∼3 μg otigomycin/ml; OliR2 an oligomycin resistant cell line, required ∼27 μg/ml for the same inhibition. ATPase solubilized from OliR2 mitochondrial fractions required 3–10-fold higher concentrations of oligomycin than did identical WT fractions to achieve 50% inhibition of activity. Resistance was correlated with altered mitochondrial ATPase sensitivity to oligomycin.

Notizen: . The electrophoretic mobility of six isoenzymes from 10 species of Crithidia from insects were compared. Five zymogram patterns emerged. Pattern I was presented by C. acanthocephali and Crithidia sp. from Euryophthalmus davisi; pattern II by C. hutneri and C. luciliae thermophila; pattern III by C. arili; pattern IV by C. luciliae luciliae, Crithidia sp. from Aedes solicitans, C. harmosa, and C. fasciculata; pattern V by C. oncopelti.

Notizen: . Activity of ornithine decarboxylase, the major rate limiting enzyme of polyamine biosynthesis, was determined in bloodstream trypomastigotes of Trypanosoma brucei brucei. The enzyme required pyridoxal-5′-phosphate, dithiothreitol and EDTA for optimal activity. Several properties of the enzyme were investigated and compared to the mammalian enzyme. Most notably, the parasite enzyme was 〉60-fold more sensitive to the inhibitor DL-α-difluoromethylornithine than its mammalian counterpart, thus making it an attractive target for chemotherapy.

Notizen: . Xanthine phosphoribosyltransferase (XPRTase; EC 2.4.4.22) was found in the promastigotes of four species of Leishmania (L. mexicana, L. donovani, L. braziliensis and L. tarentolae). In no case was there any transribosylation from 5-phosphoribosyl-1-pyrophosphate (PRibPP), forming XMP, in dialyzed preparations, unless activated by a divalent cation. Magnesium and zinc were very low in activation efficiency in all cases, while manganese was optimally efficient. Cobalt was essentially equal to manganese for activation of the enzyme from L. mexicana and L. braziliensis but much less efficient for the enzyme from L. donovani and L. tarentolae. Gel filtration profiles of cell extracts of L. mexicana on Sephadex G-200 indicated that the enzymes catalyzing the transribosylation from PRibPP to guanine. hypoxanthine, and xanthine were inseparable. All were eluted near the void volume. The enzyme for adenine transribosylation was clearly separate. When cell extracts of L. mexicana were applied to Sephadex G-100 columns, the activity toward XMP formation from xanthine eluted with the void volume, together with a portion of that for the formation of GMP and IMP from guanine and hypoxanthine. A second peak of HGPRTase (EC 2.4.2.8) eluted somewhat later and was devoid of XPRTase activity. XPRTase from promastigotes of L. mexicana is heat labile, has rather a broad pH optima, and is stable to freezing when protected by nonspecific cell protein (40,000 g supernate as opposed to 100.000 g supernates).

Notizen: . The DNA content of the hemoflagellate Leishmania brasiliensis. strain Y, has been determined by colorimetric reactions and found to be nearly 0.226 pg/cell. When this DNA is bound to filters and hybridized with labeled rRNA from the same organism, saturation is reached at 0.47% of the DNA, corresponding to an estimated 160 ribosomal gene copies. When the DNA is sheared and centrifuged to equilibrium in CsCl gradients, two major satellites of the main band (p = 1.712 g/cm3) are observed: a heavy one (1.720 g/cm3), which hybridizes with labeled rRNA, and a light one (1.699 g/cm3) with the electron microscopic characteristics of the kinetoplast DNA network.

Notizen: . Gametocyte formation was observed in six isolates of Plasmodium falciparum in continuous culture. Optimal conditions include constant temperature and addition of caffeine at 2.0 mM. Depletion of glucose in the medium and treatment with cAMP did not consistently trigger the formation of gametocytes.

Notizen: . To identify the unknown liver cell type initially invaded by sporozoiles of mammalian malaria, young rats were inoculated intravenously with large numbers of Plasmodium berghei sporozoites obtained from infected Anopheles stephensi mosquitoes. Fine structural studies of liver specimens obtained from the rats within 2 min after inoculation demonstrated the presence of morphologically unaltered sporozoites in the cytoplasm of hepatocytes. Many sporozoites were also observed undergoing cytolysis within the lysophagosomes of Kupffer cells, as well as other phagocytic cells. These observations strongly suggest direct infection of the hepatocyte by the sporozoite.

Notizen: . The role of bacterial endosymbionts in the acquisition of new phenotypic characters was studied by transplanting nuclei from an uninfected strain of Amoeba proteus into the enucleated cytoplasm of a symbiont-carrying strain. After 1–10 cell cycles, the nuclei were tested for two characters: compatibility with uninfected and infected cytoplasm, and their lethal effect against amoebae of the uninfected parent strain. A significant number of transplanted nuclei displayed both of the new phenotypic traits after a few divisions in the infected cytoplasm. Thus the influence of these endosymbionts on the nucleus of A. proteus was virtually instantaneous.

Notizen: In order to verify the applicability of biochemical methods for species identification of Trypanosomatidae, 13 species of monoxenic trypanosomatids plus the heteroxenous Trypanosoma cruzi were comparatively analyzed by three different biochemical methods. Insect trypanosomatids examined were: Crithidia acanthocephali, C. fasciculata (three varieties), C. luciliae luciliae, C. luciliae thermophila, C. deanei, C. oncopelti, Herpetomonas muscarum muscarum, H. megaseliae, H. samuelpessoai, H. mariadeanei, Leptomonas seymouri, L. collosoma, L. samueli, and Blastocrithidia culicis. Also included in the survey were aposymbiotic strains of C. deanei and C. oncopelti. Methods used were: electrophoretic profiling of endonuclease-generated fragments of k-DNA, esterase isoenzymes profiling, and polyacrylamide-gel electrophoresis (SDS-PAGE) of radioiodinated cell surface proteins. Interspecific but not intraspecific differences were detected by all three methods among the 13 monoxenic species examined. Thus, it is concluded that these methods can be successfully used, in addition to classical criteria, for species identification of insect trypanosomatids.

Notizen: A quantitative method for experimentally separating the adhesion and interiorization phases of the interaction of Trypanosoma cruzi with mammalian cells was developed. Incubation of confluent monolayers of mammalian cells with epimastigotes or trypomastigotes at 4°C allowed the evaluation of the number of adhered parasites that do not become interiorized at this temperature. Quantification of interiorized parasites at 34°C was achieved by employing hypotonic lysis to eliminate the extracellularly adhered trypomastigotes. Both adhesion and interiorization were found to be proportional to the time of exposure of cells to parasites and to the multiplicity of infection. These phenomena occur normally for trypomastigotes in the absence of serum with LLC-MK2 cells, HeLa cells, and 3T3 fibroblasts. Moreover, it was possible to obtain trypomastigotes that presented the same infectivity to LLC-MK2 cells as did parasites obtained in the presence of 2% fetal calf serum after 10 serial passages in a medium devoid of serum. Inhibition of adhesion (of epimastigotes and trypomastigotes) and of interiorization (of trypomastigotes) was obtained with inactivated normal serum from several sources, a saturation effect being observed at a final concentration of 20%. Bovine serum albumin, at the concentrations present in the sera, had no inhibitory effect. Trypomastigotes that have been pre-incubated with 40% FCS (45 min at 4°C) showed decreased adhesion and interiorization indices, effects that can be reversed by trypsinization of the parasites prior to exposure of the cells. A progressive internalization of previously attached trypomastigotes was observed on raising the temperature from 4°C to 34°C; no spontaneous detachment of parasites was detected up to 120 min. Approximately 75% of the adhered parasites were found inside the cells after 45 min at 34°C. The presence of normal inactivated calf serum during incubation at 34°C resulted in a certain degree of detachment and in a lower interiorization index.

Notizen: A reliable method for producing reproductive cysts in Tetrahymena patula is described. The procedure involves the isolation of macrostomes without cytopharyngeal pouches in microdrops of distilled water under oil. The study of silver-impregnated specimens has shown that a complex pattern of oral resorption and reformation occurs within the cyst that leads to the formation of a group of small cells with recessed oral apparatuses. These cells, called “cryptostomes,” swim very rapidly on excystment and are incapable of either feeding or reproducing. They are presumably dispersal forms. Oral morphogenesis during the transformation of excysted cryptostomes into microstomes and macrostomes is also described.

Notizen: The reproduction of Babesia ovis inside the ovary of the vector tick Rhipicephalus bursa was studied by electron microscopy. The kinetes of B. ovis invade the ovary of the tick via hemolymph. The kinete, when situated intracellularly, is transformed into a polymorphous stage that loses all features of the invasive form. The nucleus elongates enormously and forms many folds which extend throughout the cell. Subsequently, the lobulated nucleus and the cytoplasm are divided into numerous uninuclear cytomeres by invaginations of the cell boundary and by interconnecting endoplasmic reticulum. Each cytomere, bounded by a unit-membrane, measures ca. 4 μm in diameter and finally forms a new kinete. This proceeds as protrusion of the cytoplasm into an intracytoplasmic vacuole. An apical complex is initially visible at the tip of the protrusion that emerges steadily into the lumen of the expanding vacuole. The nucleus of each cytomere is incorporated into the newly formed kinete, which is surrounded by a coccidian pellicle the inner membranes of which are formed at the base of the intracellular protrusion. Nearly all of the cytoplasm is used for the differentiation of the kinete, which finally lies folded inside the vacuole. The kinete is apparently released by rupture of the vacuole. The description of this peculiar reproduction completes the knowledge of similar reproductive processes in other tissues of the tick. A comparison of the differentiation of the kinete in Babesia and in Theileria indicates a similar mode of development.

Notizen: The formidable expansion in the scope of the United Nations International Comparison Project has brought into evidence limitations of the methodology used in the first three phases. The author considers that there are two indispensable conditions needed to give renewed impetus to the ICP: (a) the objectives must be redefined, and (b) the methodology must be built on an entirely new basis. He considers the broad lines of such an evolution to be the following.(a) The objective of volume comparison must be kept distinct from that of purchasing power comparison, given that both the basic material and the formulae to be used at the aggregate level differ in the two cases.(b) At the basic heading level, it is proposed, for both volume and purchasing power comparisons, to replace the multilateral approach by a “minimum scale” binary and unilateral approach, and to use the EKS method. This will make possible an improvement in the accuracy of the estimates, a reduction in the overall costs, and a drastic reduction in execution time. What is more, it would be possible to regionalize the worldwide comparison, in the sense that the results of the basic heading comparisons already obtained at the regional level for regional purposes can be used as an input in the framework of the worldwide comparison. At the aggregate level, in the framework of volume comparison, it is proposed that a constant price procedure in the spatial sense should continue to be used. It is, however, proposed that the prices of the set of countries (GK) be replaced by a structure of common “equi-distant” prices (G). This would permit the elimination of the significant systematic distortions observed in the comparison between rich and poor countries in the first three phases of ICP. What is more, this gives maximum stability to results obtained for the same countries at different geographical levels. By using a set of common “equi-distant” quantities, the same advantage can be obtained in the purchasing power comparison.

Notizen: A number of rather traditional problems relating to the estimation of the national accounts have been raised in the recent literature. This paper examines five of these problems from the point of view of a government statistician working within certain time and resource constraints. Credibility, comprehensibility, theoretical validity, cost and analytical usefulness are the criteria which should aid in deciding how to treat such matters as the extension of the boundaries of economic production, proposed changes in the categorization of both final and intermediate expenses, the treatment of “total” welfare and estimation relating to the so-called underground economy.

Notizen: Book review in this article:JAMES MEADE: Stagflation Vol 1: Wage Fixing. George Allen & Unwin LA.

Notizen: The growth of the public sector in the post-war period and the consequences of this development for economic growth is a strongly disputed subject of economic theory and policy. In this paper the development trends of state activities in the case of the Federal Republic of Germany are presented. The structure of public expenditures as well as the tax structure are taken into consideration and possible impacts on real economic growth are analysed. The negative correlations between some kinds of public expenditures (or taxes) and the growth rate of real GNP should not be taken in proof of the growth-retarding effects which might ensue from increasing state activities. It seems to be more likely that state activities have induced shifts of resources from the formal into the informal economy. Politicians should be aware that some measures of economic policy conventionally proposed will strengthen the movement into the informal economy, thus intensifying the current problems within the public budgets as well as in the social security system.

Notizen: This paper uses five valuation methods to derive aggregate and per person estimates of the value of household work in the United States. Two general questions are posed: (1) what is the relationship between the aggregate estimates and the valuation method used, and (2) how do per person estimates vary by sex and earnings?The main observations of the paper are as follows: First, the aggregate value of household work is sizable regardless of the valuation method used. Second, aggregate estimates are extremely sensitive to the method of valuation. For example, the highest estimate is $475 billion greater than the lowest estimate. Third, contrary to earlier findings, opportunity cost valuation methods generally produce significantly higher estimates than market cost valuation methods. Fourth, per person estimates vary significantly by sex and level of earnings across valuation methods. Generally, market cost estimates.

Notizen: Income generating functions are statistical tools used to explain income inequality and other economic outcomes and behavior. These functions are often associated with a strict human capital framework, but they need not be. Instead, they may be viewed as a reduced form equation summarizing the relationship between income and various personal and locational characteristics. Following this latter interpretation, we develop the regression and analysis of variance approaches to income generating functions and estimate them empirically using micro-economic data from one low income country, Colombia. Proceeding to increasingly parsimonious specifications of income generating functions, insights are gained into the structure of incomes in Colombia.

Notizen: In this paper a definition of poverty in terms of welfare is given. A method is developed to derive poverty lines from an individual welfare function of income. The model is extended to analyse the effect of several socio-economic characteristics on the level of the poverty line. An empirical application of the method is given based on data from a survey in eight European countries in 1979. Differences in the poverty lines both between countries and between socio-economic groups within each country are considered. Finally the number of people below these poverty lines is estimated for all countries in the group.

Notizen: The Kingdom of Nepal is one of the least developed and least known countries. In order to understand the sometimes non-conventional estimating procedure used, a background section is included, describing the physical, socio-economic and institutional framework. In the second part of the paper some illustrative examples of the approaches used are given, the full description being published in four volumes, National Accounts of Nepal, National Planning Commission, Kathmandu. The last part of the paper considers the usefulness of national accounts based upon the market economy, and in general, the problem of applicability of international concepts to a developing country. What is the significance of international concepts to a developing country? What is the significance of national value aggregates in a country in which the unit of national currency does not serve as a nation-wide standard of value? Can a common denominator be found if the scale of values and the whole outlook of different groups are so different? What do people value, and does the rural population in localized economies put a monetary price on the value? Has the concept of labour force or employment, as used in industrial societies, any meaning in a society where all those capable, including small children, of contributing to daily survival do so? The conceptual problems have not yet been solved. National accounts are a useful first step in providing planners with symbols for telling a complex story in simple terms and as a kind of statistical reconnaissance, but as development planning is moving more and more in the direction of planning from below and into regional and rural development projects, household surveys are becoming essential planning and evaluation tools. Based upon twenty-five years of field experience, the author reflects upon problems and possible solutions, discussing managerial, training, substantive and statistical aspects.

Notizen: This paper describes the composition of the public sector in the United Kingdom and traces the development and contribution to the economy of the three main sub-sectors-central government, local government and public corporations—over the past thirty years. Relevant data for output, employment, fixed capital formation and national wealth set the public sector into perspective with the economy as a whole and illustrate how its share of human and other resources has changed over the years. While all four measures show the public sector share of the total to have been around 30 percent in 1980, historically the changes have moved very differently. The slow, but fairly steady, increase in the share of employment and output contrasts with very marked changes in the other two measures. Although public sector fixed investment nearly doubled in real terms between 1950 and 1980 its share of total investment declined from 48 to 31 percent, a much smaller share being taken by dwellings, electricity supply and the railways. In terms of the share of national wealth the public sector moved from a state of indebtedness to the rest of the economy in the fifties and sixties to a position of holding nearly one third of the value of tangible and financial assets in the late seventies.A small part of the paper considers the international dimension, but because few other countries use the concept of a public sector, this section examines only the relationship between total tax revenue and GDP in a number of countries and employment in general government.The problems of determining the boundary of the public and private sectors occurs most frequently at the interface between public corporations and private enterprises; the rules for deciding classification are set out in so far as they can be specified.The last sections of the paper put the statistics into their policy context and consider the value of public sector aggregates. The conclusion is that a general case cannot be made to justify assembling public sector aggregates for all countries; the need will be determined by the economic policies being pursued in a particular country. Although the United Kingdom gives considerable prominence to a public sector financial aggregate, the Public Sector Borrowing Requirement, the functions of the public corporations and the rest of the public sector are so disparate that consolidated accounts for the public sector are no longer prepared.

Notizen: Has the underground economy caused the increase in United States GNP in recent years to be understated relative to earlier periods? The ratio of employment to population provides powerful evidence that it has not. This ratio’ was as high in the middle 1970s as in previous periods and in 1978–80 rose to its highest level of the postwar era, suggesting that employment growth has not been understated. Employment series based on both establishment reports and household surveys yield exceptionally high ratios in recent years. This article provides a step-by-step explanation of why employment data are pertinent to the question raised about GNP.This explanation may be summarized as follows. GNP measured as the sum of final products is not understated unless GNP measured as the sum of national income and other charges against GNP is also understated. Appreciable understatement of the growth of charges against GNP as a result of growth of the underground economy is highly unlikely in the absence of understatement of the growth of wages and salaries, because of the way the estimates are made. Understatement of the growth of wages and salaries without understatement of the growth of employment based on establishment reports is highly unlikely because of the way data are collected.The article explains briefly the relationship between income tax evasion and errors in measuring the various components of charges against GNP. It also explains how illegal activities are meant to be handled in GNP measurement.

Notizen: In this paper we deal with the question of which measures of economic well-being are adequate to identify those groups of households in the U.S. whose economic conditions justify public concern and assistance. We derive a utility based measure of economic well-being from the estimation of a complete set of consumer demand equations. The demand system is Lluch's Extended Linear Expenditure System (Lluch, 1973). Household characteristics are incorporated using the scaling method proposed by Barten (1966). Using the welfare indicator derived, we study the composition of the poorest part of the population, using data from the 1972–73 Consumer Expenditure Survey. We compare our results with those obtained using various other welfare indicators, including the official U.S. poverty line. We show that using different family composition adjustments significantly and systematically affects just who are considered to be at the bottom of the welfare distribution. We finally suggest that program designers therefore can improve their target efficiency by carefully selecting from among the acceptable indices of welfare when defining program eligibility.

Notizen: In this article an attempt is made to generate internationally comparable income distribution data for the Federal Republic of Germany (1974), Mexico (1968) and the United Kingdom (1979). To that end, the same income concept and income unit were adopted for each country, i.e. respectively household available income and the household. Moreover, incomes from various sources were adjusted for inconsistency with National Accounts according to Altimir's methodology. The paper finds that the distribution of persons by household income per equivalent unit is probably the best way of looking at the distribution of economic welfare. It further demonstrates that the distribution of persons by household available income per capita is much closer to this ‘ideal’ distribution than the distribution of households by household available income. Finally, the paper discusses some of the problems arising from the fact that one normally works with grouped data. It is found that in the case of the three countries under study, grouping is likely to have had only a small impact on the results.

Notizen: This paper provides a description of the annual Input-Output Tables for Canada. It describes the accounting framework and notes its close affinity to the one described in the United Nations report, A System of National Accounts. It demonstrates the ready derivation of GDP and Expenditure on GDP, both in current and constant prices, from the Input-Output Accounts as well as their relationship to the other subsystems of the Canadian System of National Accounts, particularly the Income and Expenditure Accounts and Real Domestic Product by Industry. Compatibility of basic accounting records of the transactors with the rectangular (commodity-industry) format of the Canadian tables is described. The need to have a consistent commodity classification and to develop a consistent valuation of all transactors in the economy is emphasized. The particular formulation of the Input-Output Impact tables is noted. The problem of deflating trade margins and the resolution of this problem is described. A strong plea is made for the economics profession to pay more attention to the problem of aggregation; all economic analysis is approached with blinkers but the aggregation problem isn't even recognized as a blind spot in most analyses.

Notizen: Cooperation between the Austrian and Hungarian central statistical offices in the field of industrial productivity has a history of two decades. The first comparison, carried out in 1965, was partly experimental in objective and nature. The second full scale survey took place a decade later in 1975. This was followed by a further study of about two years duration of the level of productivity and the factors influencing it in three sectors: food, metallurgy and engineering. For this study the three sectors were broken down into 31 sub-branches and nearly 400 product groups. An important and labour-intensive element of the comparisons was harmonization of the sector and product classification system; UN recommendations were increasingly helpful for this work, and relying upon them will be expedient also in the future.In the decade under review the productivity advantage of Austrian industry increased, from about 40 percent in 1965 to an average 75 percent in 1975. The dispersion of sectoral productivity indices around the average value was significant in both years.The similarity of the 1965 and 1975 comparisons offered an exceptional opportunity to examine the reliability of extrapolation. The investigations unambiguously demonstrated that extrapolation did not give reliable results for a period as long as ten years, primarily because of structural changes in production and changes in price weights.The most important conclusion to be drawn from the investigation of the three selected branches is its extraordinary usefulness from the economic, political and methodological points of view. A further important conclusion is that the method of comparison must be selected in the light of an extensive consideration of the output and technological structure of the branches.

Notizen: The paper by Gerardi covers considerable ground, touching on a wide variety of issues in the area of international comparisons of product and purchasing power. Since our views on most of these subjects have been expounded in one or another of the International Comparison Project volumes and we will concentrate mainly on the central issue raised by Gerardi of the selection of an aggregation process that must somehow take account of the tastes of all the people who are the subject of an international comparison inquiry. In addition, we comment on some other points including the notion of special purpose PPPs. Finally, we make a brief statement about where we think future research will be most useful in improving international comparisons.

Notizen: Just as intertemporal price indices have two functions, to measure price changes and to deflate current values to constant values, this is true also for interspatial price indices, purchasing power parities (PPPs). In practice these two functions of PPPs, for conversion and for comparing price levels, are not always distinguished, and this may have some disadvantages since in a number of cases the differences between the two PPPs might be considerable. The authors review the differences in content of the two types of PPPs, and make some suggestions for making the distinction more explicitly.

Notizen: This paper explores the possibility of using the Classification of the Functions of Government published recently by the United Nations (COFOG) in order to segregate intermediate from final use of government production in the national accounts. It is argued that the notorious difficulties of doing that can be traced to two reasons, one the multiplicity of theoretical concepts, and the other the lack of sufficient detail at the statistical level. The first can be removed by clarifying that on the production account of an economy only production and not welfare is to be measured. The second seems to be overcome by the three-digit detail of COFOG. It is shown that many of these categories are now sufficiently homogeneous for a panel of experts to agree in assigning them to either intermediate or final use, although for a number of categories this is still difficult. The question is whether consensus in the major categories is large enough to consider the remaining controversial ones as border cases, normal in any classification and solved in the last instance not by argument but by convention. Some preliminary figures for the intermediate part of government production are given.

Notizen: The public sector is defined here to include government plus public enterprises. Historically, economists and statisticians have been more concerned with its separate components than with the public sector as a whole, but it is suggested that the public sector may be an appropriate concept for studying several current problems of economic policy.While there is general agreement as to what constitutes government, countries have differing views about what makes an enterprise public. Differences in country definitions of public enterprises are identified as one of the main problems in making international comparisons for the public sector.Statistics are presented for up to 16 OECD countries on the share of the public sector in total final demand, value added, employment, and net lending. It is argued that there is rarely a unique answer to the question “How big is the public sector?” For most countries judicious selection of data and careful definition will lead to different conclusions about the size and growth of the public sector.Because of the lack of data, it is not possible to analyse public sectors in developing countries in the same detail as OECD countries. The evidence available suggests that while public sectors are about the same size in both OECD and developing countries, public enterprises play a more important role in the latter.

Notizen: Following the growth of the public sector traditional measures of the size of the public sector have appeared to be inadequate for policy purposes. In the article the role of the public sector in the Finnish economy is described first by using some traditional methods and indicators. The historical background of the development is briefly discussed. After that some specific problems of the measurement are discussed. These problems include measurement of output and productivity, definition of appropriate balance of the public sector, different measures to describe the size and scope of the public sector, role of tax reliefs and subsidies, different organizational arrangements, public sector regulation etc.The growth of the public sector takes many different forms and it appears to be more difficult than formerly to obtain a comprehensive picture of the scope of the public sector. For different purposes different indicators have to be used. At the end of the paper the implications of the changing emphasis in the public policy are discussed.

Notizen: This paper outlines a general strategy for constructing socio-demographic matrices, starting with a set of initial estimates based on available data and ending with a set of final estimates adjusted to meet the constraints connecting their true values.The method is described and illustrated by a numerical example taken from the author's current work on marital transition matrices. The figures relate to the male population of England and Wales in 1978 and are based on British official statistics of population numbers, births, deaths, migrations, marriages, widowhoods and divorces.

Notizen: Extended accounts of total income and product and associated capital stocks for the United States, in current and constant dollars, are offered for the years 1946 to 1976. They include intangible and tangible capital accumulation and non-market and market outputs in all sectors, services of government and household capital and of unpaid household labor, and opportunity costs of students. Defense and police services are classified as intermediate product; a portion of commercial media services is counted as final product. Expenses related to work are subtracted while the values of employee training and human capital formation and net revaluations of existing tangible capital are added.Total incomes (TISA) net national product was 50 percent greater than official Bureau of Economic Analysis (BEA) NNP in 1976. BEA gross private domestic investment was only about 18 percent of TISA gross capital accumulation. Intangible investment and TISA net domestic capital accumulation grew more rapidly than BEA net private domestic investment. Household investment has been growing while there have been sharp declines in government investment, particularly in research and development. Contrary to some views of the import of the narrower BEA accounts, total capital accumulation appears to have risen considerably more rapidly than total consumption, 6.3 percent versus 2.2 percent per annum from 1946 to 1976, thus increasing sharply its share of TISA GNP.

Notizen: The paper is mainly concerned with statistical problems relating to intermediate services that arise in the construction of national input-output (I–O) tables. Though these problems are sometimes discussed in the literature, their precise nature is usually not spelled out in any detail and this is done in the paper. The problems are closely related to the company-establishment statistical dichotomy permeating the ultimate sources and allocation of intermediate services. Important examples can be found regarding the statistical treatment of head offices, research and development expenditures, and international trade of intermediate services. Presently used procedures for Canadian and U.S. I–O compilation show evidence of statistical inconsistencies and lack an appropriate framework to utilize full information. The paper suggests a possible approach for reconciling company and establishment data based on industrial organization linkage studies at the microlevel. Considerable empirical support is offered, using various official Canadian statistical publications, to show that the suggested approach is both feasible and has desirable properties.The paper goes on to argue that the contemporary information technology revolution has profound implications for I–O compilation and use with special reference to intermediate services. Four major implications are explained in the context of the growing microelectronics technological change and related literature. Some basic suggestions are put forward with regard to joint-cost allocation and inter temporal comparisons problems with respect to I–O compilation. It also appears that some fundamental rethinking of commonly accepted standard industrial classification conventions may be called for in the near future if I–O tables are to remain relevant and viable. The paper thus features a somewhat broader view of I–O statistical problems than usual and attempts to show that this view is potentially appropriate to questions of economic policy formulation.

Notizen: International comparisons always raise difficult problems, more especially when they deal with services which are jointly financed by households and government in varying shares with varying procedures in each country. This is obvious in the case of health where the area itself, the principles of economic analysis and the UN method of National Accounting appear to be either vague or unwieldy. Before any proposal it is necessary to review what is involved in the concept of service and the possibility of delimiting the health field inside which economic measures are feasible. Then using the SNA concept and with the help of six interdependent tables we propose two aggregates: the National Medical Consumption and the Current National Expenditure on health. The detailed and harmonized breakdowns of these global results make it possible to compare the structures of values, prices and quantities on an international base.

Notizen: Stagflation is a combination of an increasing rate of inflation with a decreasing rate of real growth. It appears when the inflationary gap of production costs raises faster than the inflationary gap of expenditures on Gross Domestic Marketable Product. The decomposition of these two gaps into their main elements gives then the possibility of determining the sources of the inflationary increase in costs and the causes of the relative retardation of the inflationary increase in expenditures. The main cause of stagflation in 1974 for France and Germany was the huge rise in oil prices which had not been immediately followed by an equal rise in prices of their exports. The inflationary rise in wages is an almost permanent factor of stagflation in France; in Germany its responsibility is involved only before 1975. In France the insufficient increase in the inflationary gap of expenditures was mainly due to the restrictive monetary policy and to the official price regulation. In Germany the restrictive monetary policy also contributed to the slowdown in demand in 1974 and 1975. In 1977, on the contrary, the main cause of stagflation was the slackening of export demands due to the world recession and the revaluation of the DM.

Notizen: There are two types of masked layers in seismic refraction work: the velocity reversal (low-velocity layer) and the hidden layer (insufficient velocity contrast or layer thickness). On the basis of an analytical formulation of the general case of a masked layer under an overburden of plane and parallel multiple refractors the two limiting cases are discussed: the solution resulting from an uncritical interpretation of the measured time-distance curve and the blind zone solution. Between these two limiting cases there is a variety of possible masked layer solutions. These no-blind zone solutions—as well as the blind zone solution itself—are formulated separately for the velocity inversion and the hidden layer case.For the evaluation of some no-blind zone solution a diagram is presented which can be used for any case of multiple refractors in the overburden of the masked layer. However, it is only for the three- and the four-layer case that a blind zone interpretation by use of diagrams is advisable. Such diagrams are presented together with the basic sets of formulae which contain as parameters only ratios of velocities and layer thicknesses. As the velocity of the masked layer is usually unknown the diagrams are principally constructed to show the dependence on the masked layer velocity. This is useful for estimation of the largest possible error.

Notizen: Wave equation migration techniques have shown the limits of traditional stacking methods with data from tectonically complicated areas. An improved stack can be obtained utilizing the dip-moveout correction technique based on offset continuation. The properties and the limits of the algorithms used are summarized briefly.Several synthetic and real data examples are shown and compared with the results obtained using conventional processing in order to show the focusing effects and the strong improvement in signal-to-noise ratios, both at the stacked and migrated section level. The possibility of exploiting this technique to transform multiple coverage into increased spatial resolution is illustrated with examples.

Notizen: The accuracy of short length digital linear filter operators can be substantially increased if the sampling interval as well as the abscissa shift are properly adjusted. This may be done by a trial and error process of adjustment of these parameters until the error made by the filter operator, applied to a suitably chosen test function, is smallest.As an illustration of the application of this method, 7-, 11- and 19-point filters for the calculation of Schlumberger apparent resistivity from a known resistivity transform are designed. Errors with the new 7-point filter are seen to be less than those with a 19-point filter of conventional design. The errors with the new 19-point filter are two to three orders of magnitude smaller than those made by the conventional 19-point filter.The new method should provide digital linear operators that allow significant improvements in accuracy for comparable computation efforts, or substantial reduction in computation for comparable accuracy of results, or something of both.

Notizen: A well-known technique for the migration of normal-incidence two-way travel-time maps is extended to common-source-point travel-time data. The travel time and the travel-time gradient are used to compute the parameters defining the tangent plane of the reflecting interface. It is also shown how the curvature matrix of the received wavefront can be used to compute the curvature of the reflecting interface. The method is initially derived for common-source-point data and then extended to common-midpoint data.In a three-dimensional medium the wavefront curvature matrix is computed by solving a 2 × 2 symmetric matrix Riccati equation. In a two-dimensional medium and in a medium with constant velocity gradient, the wavefront curvature matrix is computed by solving a scalar Riccati equation and two linear equations. The migration procedures are also simplified.When the velocity function is unknown, the migration procedures cannot be used. An inverse modeling algorithm which simultaneously performs the migration and estimates the velocity function must then be applied. Two different inversion schemes are discussed briefly.

Notizen: Time-domain-induced polarization (IP) laboratory measurements were performed on about 200 fine sediment samples with varying water content. The results permitted an analysis of IP properties of clays, loams, silts, and sands.Particular emphasis has been given to the analysis of the chargeability m as a function of lithotype and the water content.By analyzing decay curves, a new parameter was identified. It is a statistically specific characteristic of the lithotype and is independent of the water content. Therefore, it provides a diagnostic parameter for lithotype identification. In association with the values of chargeability and electrical resistivity, this parameter permits a reliable evaluation of water content and yields useful information about the porosity and permeability of the lithotype.

Notizen: Approaches to the reduction of bias in the computation of the elements of the magnetotelluric impedance tensor have been proposed in the past by several authors. In this paper a clear distinction is made between random errors and bias errors. No effort is made to reduce either, but the emphasis is on their estimation. Both types of errors depend critically upon the polarization of the magnetic field. The random error increases with increasing noise-to-signal ratio in the electrical field, and it is rather insensitive to noise in the magnetic field. The bias error increases with increasing noise-to-signal ratio in the magnetic field. Expressions for random errors and maximum bias errors are developed and discussed using a single station set-up. Random errors with a reference station set-up are also calculated.

Notizen: The main object of the experiment was to assess the effect of the relative proportion of non-protein nitrogen (NPN) to total nitrogen in silage on digestion in the sheep. Four unwilted perennial ryegrass silages were made with the addition of formic acid at 0, 2·2, 4·2 and 5·2 litres t-1 to provide foods with NPN proportions reducing from 0·26 to 0·20 of the total N. The digestion of the silages was studied in a 4 × 4 Latin Square experiment with sheep cannulated in the rumen, proximal duodenum and terminal ileum.Results for organic matter (OM), cellulose and N showed no major difference between silages in their digestion in the rumen, small intestine and caecum and colon, though small differences (P 〈0·25) in rumen fermentation pattern and in the proportion of digestible OM disappearing in the small intestine were observed. Concentrations of ammonia N in the rumen and rates of rumen bacterial protein synthesis did not differ significantly between silages and there were no treatment effects on the passage of individual amino acids to the small intestine. The results indicate that the proportions of NPN to total N in the silages examined had little influence on the efficiency of silage N utilization in the rumen or on the passage of undegraded dietary protein to the small intestine.

Notizen: Two experiments were carried out to determine whether the differences in intake and feeding value previously shown between two grass cultivars when offered to ruminants as chopped artificially dehydrated (dried) material could also be demonstrated when the grasses were offered in other forms. Two cultivars of tetraploid Italian ryegrass (Lolium multiflorum), Sabalan and Tetila, were established in the same field in 1975. In 1976 they were grazed and conserved (two cuts of primary growth) as dried material or as silage.The composition of the herbage selected at pasture and conserved showed higher concentrations of normal detergent fibre and acid detergent fibre in the dry matter for Tetila than for Sabalan, but differences between cultivars in digestibility were small. In both grazing and winter feeding trials differences in voluntary intake between the two cultivars were not significant, but at pasture young beef cattle spent less time grazing and tended to spend more time ruminating on Tetila than Sabalan. There was no measure of animal performance at pasture but liveweight gain was 15% higher for Sabalan than Tetila when both were offered to young beef cattle as the sole feed of dried grass or of silage. The voluntary intakes of the three forms of feed were very similar, which in part reflected a similarity in digestibility. However, gains were lower for calves given silage than those given dried grass. This may have been due to a lower efficiency in the utilization of the nitrogeneous components of silage for tissue growth than those of dried grass.

Notizen: Four grass silages, all made in mid-July from second-harvest perennial ryegrass swards, were compared in a 16-week feeding experiment with twelve Ayrshire cows. Two silages were unwilted and two wilted. All the silages received formic acid (‘Add-F’) at the rate of 3 litres t-1 either with formalin at the rate of 1 litre t-1 or without formalin. The unwilted and wilted silages had mean dry matter (DM) concentrations of 200 and 243 g kg-1, and in vitro D-values of 0·293 and 0·272 respectively. The silages were offered ad libitum plus 6 kg concentrates per cow per day. The daily intakes of unwilted and wilted silage DM were 10·2 and 9·2 kg per cow respectively on the formic acid treatment, and 10·2 and 9·2 kg on the formic acid + formalin treatment. The mean daily milk yield on the unwilted silage treatments was 19·2 kg per cow which was significantly higher than the yield of 17·2 kg per cow on the wilted silage treatments. The formalin had no significant effect on milk yield. The four silage treatments had small and non-significant effects on milk composition. It is concluded that the unwilted silages, which had excellent fermentation characteristics, were superior to the wilted silages as a feed for dairy cows.

Notizen: Book review in this article Forage Evaluation: Concepts and Techniques Edited by J. L. Wheeler and R. D. Mochrie Improved Feeding of Cattle and Sheep By P. N. Wilson and T. D. A. Brigstocke Nitrogen Cycling in West African Ecosystems Edited by T. Rosswall Land Evaluation By S. G. McRae and C. P. Burnham

Notizen: Three field experiments showed that perennial ryegrass can be successfully slot-seeded into an existing Festuca-Agrostis sward. Ryegrass survival was satisfactory in all cases but was improved on a low fertility site by the application of fertilizer N, P and K in the slot at sowing.The effect of varying inter-row spacing from 37·2 to 15 cm was measured in a 3-year experiment. In year one, involving seven cuts, slot-seeding increased total herbage dry matter harvested by a mean value of 17%; inter-row distances of 22·2-30 cm gave the optimal combination of ryegrass + old sward herbage. Differences in yield between inter-row spacings declined in the subsequent two years, as the rows of ryegrass thickened. Ryegrass digestibility (measured only in year two, from six cuts) was higher than that of the old sward; total metabolizable energy harvested from 15-cm rows was 20% higher than that from unsown controls. Increasing N input from 200 to 400 kg ha-1, starting in year two, only produced a significant increase in total herbage harvested in year three but proved effective in increasing the ryegrass contribution from the wider spaced rows.

Notizen: In three separate feeding experiments using a total of thirty individually-housed Ayrshire cows three silages made from perennial ryegrass were given ad libitum together with supplements of four different hays in the long form. The in vitro D-values of the silages ranged from 0·298 to 0·283, and the hays from 0·280 to 0·200. The daily intake of hay DM varied from 0·2 to 4·2 kg per cow and was given either without or with a daily maximum of 2·2 kg concentrate DM containing 379–527 g CP per kg DM. On average, 1 kg hay DM decreased silage intake by 0·24 kg DM with a range of 0·21–1·20 kg. The hay supplements had only small and non-significant effects on total DM intake, milk yield and milk composition, but increased the daily intake of drinking water. In three behavioural studies, the eating and ruminating times expressed as min per kg DM did not differ significantly between the various supplement treatments. It is concluded that hay has only a marginal value as a supplement for grass silage, although the hay could serve as a useful ‘buffer’ feed if the amount of silage was limited.

Notizen: Two areas of an early-heading perennial ryegrass cv. Cropper were harvested by either a precision-chop or a flail harvester at around 50% ear emergence (15 May 1978) and 14d later (29 May). Formic acid (85%) was applied at the rate of 2·2 litres t-1. Mature crossbred wethers were used in a 2 × 2 factorial design to determine the effect of stage of maturity and method of harvesting (chop length) on the in vivo digestibilities of formic acid-treated grass in experiment 1 and formic acid silage in experiment 2. Apparent digestibility coefficients were determined at a fixed level of feeding for both grass and silage and at ad libitum access to feed for silage only.There were no significant differences in the concentrations of crude protein (CP), ether extract (EE), acid-detergent fibre (ADF) or acid-detergent lignin (ADL) in grass or silages of differing chop lengths but the later cut forages had significantly higher ADF and ADL concentrations and lower CP concentrations than the early-cut forages. The ADF and ADL concentrations were also higher in the silages than in the corresponding grasses.In general, the fermentation characteristics of precision-chopped silage were better than for the corresponding flail-cut silage but date of harvest was a more important determinant of quality and the late, flail-cut silage had the highest butyrate and ammonia N concentrations and the highest pH (411) of any treatment. There was a significantly higher intake of precision-chopped as compared with flail-cut silage with both the early-and the late-cut silage but there were no significant differences attributable to stage of maturity (i.e. date of harvest) or significant interaction between chop length and maturity. The slightly increased intake of early harvested, precision-chopped silage as compared with late precision-chopped silage was not significant.Dry matter digestibility (DMD) of the grass decreased at a rate of 0004 units d-1 post 50% ear emergence. The results of experiment 2 indicated a decrease of 0·207 units d-1 in silage fed at a similar level. The late-cut silage (DMD 0·292, mean of both harvesting treatments) thus had a significantly lower digestibility than the corresponding grass (mean DMD 0·247). Chop length had a variable influence on the DMD of both grass and silage fed at a fixed level but treatment differences were non-significant. However, a trend towards higher digestibility of flail-cut as compared with precision-chopped silage was apparent and this became statistically significant when the animals were allowed ad libitum access to feed. This may be a response to the generally lower intake of flail-cut silage.

Notizen: Book review in this article Weed and Pasture Management in South Africa Edited by N. M. Tainton Collecting and testing tropical forage plants Edited by R. J. Clements and D. G. Cameron Herbage Intake by Grazing Dairy Cows By J. A. C. Meijs

Notizen: Two experiments were carried out to evaluate propionic acid-treated hay as a feed for sheep in which eighteen ewes (experiment 1) and eighteen ewe lambs (experiment 2) were fed ad libitum on hay only. At feeding, the propionic acid-treated hays had higher D-values and water-soluble carbohydrate concentrations, but a lower dry matter concentration, than the untreated hays. The voluntary feed intake and liveweight gain of the sheep fed on two acid-treated hays and on an untreated hay in experiment 1 were similar. In the second experiment an acid-treated moist hay was eaten in greater amounts by the sheep and liveweight gains were greater than on the corresponding untreated hay, but were not significantly different from those of sheep fed on field-cured hay.

Notizen: Six varieties of white clover, each grown with perennial ryegrass, four intervals between cuts and two levels of applied nitrogen in all combinations, were compared in a field experiment during the first 27 months after sowing. Information about yields, crop fractions, heights and ryegrass tillers has been presented in an earlier paper (Wilman and Asiegbu, 1982). The present paper is concerned with the more detailed studies of white clover, which help to explain the yield results and contribute to the understanding of the response of this species to management when grown in competition with grass.Increasing the interval between harvests increased the length of clover stolon per unit area of ground and increased stolon diameter, petiole length, weight per leaf and number of leaves harvested as a proportion of the number present in the sward while only slightly reducing the rate of leaf emergence, helping to explain the positive effect of increasing the interval on clover yield noted in the earlier paper. During regrowth, successive leaves had longer petioles and the length of individual petioles increased beyond the stage at which the leaflets were fully opened. Weight per leaf in clover increased considerably from April to June and declined to below the April value by October. It was shown that weight per leaf can be greatly increased by increasing the interval between harvests without reducing the number of leaves harvested per unit area per year. The stolon length measurements provided some support for the view that medium large-leaved varieties of white clover can with advantage be defoliated rather less frequently than small-leaved varieties. Stolon length was less adversely affected by applied N in the medium large- than in the small-leaved varieties. The small-leaved varieties had thinner stolons than the medium large-leaved varieties but about twice the stolon length when no N was applied, and a relatively high proportion of leaves which escaped defoliation. The application of N reduced stolon diameter, increased petiole length and had little or no effect on weight per clover leaf.

Notizen: Data from twenty-two comparisons carried out at ADAS Experimental Husbandary Farms are used to compare untreated and formic acid-treated silages. Additive treatment led to an improved fermentation in some crops, particularly those of low DM concentration (〈262 g kg-1). Where this occurred there were associated benefits in silage digestibility (+0·234 units), intake (+16%) and the growth rate of young cattle (+0·28 kg d-1). Where the fermentation of the untreated silage was good, both digestibility and animal performance associated with treated and untreated silages were similar. It is suggested that the justification for using formic acid in a commercial situation is thus restricted to occasions where the untreated crop would be liable to develop a clostridial fermentation. These may be when crops contain less than 35 g water-soluble carbohydrate kg-1.

Notizen: The change in structure of continuously grazed versus infrequently cut swards of perennial ryegrass (Lolium perenne L), cv. S23, was investigated during their first full harvest year. Measurements were made from early May until late September. The intensity of stocking by sheep in the grazed sward was adjusted in an attempt to maintain a high level of radiation interception and the cut sward was harvested at approximately monthly intervals.The herbage mass, lamina area index and radiation interception of the cut sward varied in a cyclic pattern between harvests but in the grazed sward these parameters showed considerably less variation, although they all increased early in the season and then declined later. The proportion of dead material above ground increased throughout the season in both sward types but was more marked in the grazed sward.There were major differences between the grazed and cut swards in the number of tillers per unit ground area; the difference became more marked throughout the season and by September the tiller densities in the grazed and cut swards were 3·204 m-2 and 6·203 m-2 respectively. Divergence in tiller density was associated with differences in specific stem weight and leaf area per tiller.Rates of appearance and death of leaves on tillers in the grazed sward were determined. During May, leaf appearance exceeded leaf death but this was reversed in June. During the rest of the season as a new leaf appeared on a tiller so the oldest leaf died.

Notizen: A rising-plate meter was used in a double sampling technique to measure the herbage mass of rotationally grazed perennial ryegrass-white clover swards over a period of 2 years. The meter was calibrated by developing a linear regression between meter reading and herbage dry matter mass as measured by cutting 0·2-m2 quadrats to ground level.There was a strong relationship between meter reading and herbage mass, and correlation coefficients were consistently 0·2 or above. The calibration regression was normally constant for extended periods, especially over the winter and spring. The relationship was more variable over the summer but appeared to follow a pattern that was to some extent repeatable between years. The slope of the regression (kg DM ha-1 cm-1) was 312 and 267 in the two winters and reached values of 800 and 452 in the two summers. The calibration relationship was adequately described by a linear model over the winter and spring but there was a tendency for a curved relationship in mid-to late summer.The standard pooled regression found with winter ryegrass-clover swards was not applicable to the more erect prairie grass, and the standard regression overestimated slightly the yield of heavily grazed swards. There was no evidence of a difference in relationship between irrigated and non-irrigated swards over the summer.The individual meter readings could be used to develop a useful diagrammatic picture of the changes that occurred in sward structure as the pastures were subjected to different managements and this could be used to illustrate problem areas in pasture management.The meter was useful in overcoming the problem of variability of herbage mass within paddocks and could give precise estimates of herbage mass, especially when it was possible to use a pooled regression encompassing a large number of calibration cuts. In these cases the meter could be used to detect differences of about 8%.

Notizen: A numerical technique to compute the resistivity transform directly from the observed Wenner sounding data has been developed. In principle, the procedure is based on a decomposition method and consists of two steps: the first step determines a function that approximates the apparent resistivity data and the second step transforms this function into the corresponding kernel by an analytical operation. The proposed method is tested on some theoretical master curves. A high degree of precision is achieved with very little computer time. The applicability is shown on two field examples.

Notizen: A suite of electrical, radiation, and mechanical borehole probes were run in a 76-mm-diameter borehole drilled to a slant depth of 380 m in leptite and granite. The hole is located in Precambrian bedrock in central Sweden where a site is dedicated to in-situ experiments pertaining to the disposal of radioactive wastes. The challenge to borehole logging methods for such site investigations is to resolve geological features and fluid flow parameters in geological sites which are initially chosen for their homogeneity, low porosity, and minimal fracturing. The Stripa borehole is characterized by high electrical resistivity values in the 20–100 kΩm range, by acoustic velocities around 5800 m s-1 (which is close to laboratory values on intact specimens), and by total porosity of around one volume percent. In this context, probe resolution was adequate to produce interpretable information on almost all of the logs.Two principal rock types were encountered in the hole: granite, of quartz monzonitic composition, and leptite. The granite and leptite intercepts are subdivided into units characterized by mafic mineral content, sulfide mineral content, and electrical and radiation properties. Iron-rich zones in the leptite are highly anomalous on the gamma-gamma and neutron logs; thin mafic zones in the granite can also be distinguished. Occurrences of a few percent pyrite are detected by the electrical, gamma-gamma, and neutron logs. Although overall porosity is quite low throughout the hole, analysis of the resistivity and neutron logs indicates the porosity increases by a few volume percent at fracture zones. The differential resistance and caliper probes detect borehole diameter roughness of less than 1 mm, helping to confirm acoustic waveform anomalies which are indicative of fracture zones. Compres-sional wave transit time and shear-wave interference patterns usually occur coincident with open fractures observed in core, the correlation being especially good at major fracture zones.

Notizen: The use of conventional CDP-stacking in the processing of reflection data imposes restrictions on the horizontal and vertical resolution. Ideally, the final seismic section should consist only of short offset or, in practice, near-trace primary energy. Through the use of the iterative stacking algorithm, the signal-to-noise ratio on a single trace in the CDP-gather may be improved to an extent comparable to what occurs on a conventional stacked trace. By using this approach and treating the near-trace section after iterative stacking as the final section, the seismic resolution can be improved.

Notizen: A Fredholm integral equation of the first kind with respect to the surface charge density is presented via a weighted residual formulation in the standard isotropic problem. The surface charge densities are numerically obtained by solving the well-known Fredholm integral equation of the second kind, where the new equation can be regarded as a constraint. The accuracy of boundary element solutions is examined in connection with the violation of such a constraint and the “modified reciprocal averaging techniques” are proposed.

Notizen: The roots of the so-called shaly-sand problem in hydrocarbon evaluation lie in the effect of relatively fine-grained minerals upon measured electrical parameters of granular reservoirs. This influence manifests itself as an excess conductivity, over and above that due to the purely geometric effects of electrolyte distribution within the pore space. For formations with low shaliness, this excess conductivity is usually insignificant in typical oilfield situations.The influence of shaliness upon observed values of formation resistivity has been appraised by collating core-sample data from four different reservoirs. It has been demonstrated that during the course of electrical measurement under conditions of full electrolyte saturation, any given lithology can exhibit both negligible and highly significant shale effects depending upon the resistivity of the interstitial aqueous electrolyte. The effects of shaliness are also governed by the degree of water saturation.Because the manifestation of shaliness in electrical data is not a function of lithology alone, recourse is made to a more realistic concept of shale effects whereby a formation, or section of a formation, is classified as “effectively clean” or “effectively shaly” according to whether it obeys or defies, respectively, the fundamental empirical laws of Archie (1942). In particular, since an intrinsic formation factor can be obtained directly in fully-saturated effectively clean reservoirs, whereas only an apparent quantity may be recorded directly in fully-saturated effectively shaly reservoirs, the ratio of apparent to intrinsic formation factor serves as a useful conceptual indicator of shale effects, attaining the limiting value of unity only under effectively clean conditions.In the context of electrical measurement the terms “shaliness” and “shale effects” are evidently not synonymous and it is the latter which should be considered when selecting equations for the computation of water saturation. The implications for well-log analysis follow through formulated guidelines that describe the relative levels of shale effects in different zones of lithologically uniform reservoirs.

Notizen: Shear waves can today be generated and observed, though not with the flexibility and the technical standard of compressional waves, and they can be identified in seismograms by various means. Their potential lies not so much in their lower velocity (corresponding—for the same frequency—to shorter wavelength and higher resolution) but in the fact that they probe the earth with stresses and strains that differ from those of compressional waves. Full utilization of the information potential of shear waves, therefore, requires combined use of P-and S-waves.Complications in the combined use of different wave types should be regarded as opportunities to obtain additional information. A typical example is the observation that the depth of one and the same interface estimated on the bases of P- and SH-reflections, respectively, can differ significantly. This discrepancy may be due to the anisotropy of a finely layered medium. Under favorable circumstances some of the parameters describing this anisotropy can be deduced from the different depth estimates and the curvature of the squared-offset/squared-time representation of the different reflections. Since in anisotropic media vertically polarized shear waves are significantly different from horizontally polarized ones, the combined observation of all three waves opens up additional possibilities.

Notizen: An interpretation scheme for horizontal-loop EM measurements is presented for a permeable sphere model. The induced multipole moments are found to contribute significantly even at very low frequencies for a permeable conductor. The anomaly profiles are computed considering multipole excitation (up to 20) to study the effect of depth of burial and permeability of conductor. The anomaly half-width along with the inphase and quadrature anomaly amplitudes allow direct interpretation of the parameters of the sphere. The above scheme is suitable for results of Dighem II (coplanar configuration), Slingram and Max Min II measurements.