Increase In Total Output Research Articles

The influence of a diet rich in wheat fibre on the human faecal flora.

The effect on the faecal flora of adding wheat fibre to a controlled diet in four healthy volunteers for a 3-week period has been observed. No change in the concentration of the bacteria in the bacterial groups counted was found, although there was a slight increase in total output associated with increased faecal weight. The predominant organisms in all subjects were non-sporing anaerobes, but the dominant species in each subject was different and was unaffected by changing the diet. Similarly, the concentration of faecal beta-glucuronidase detected in two subjects was unaltered and the concentration of clostridia able to dehydrogenate the steroid nucleus found in one subject was unaltered. It is suggested that the faecal microflora is not primarily controlled by the presence of undigested food residues in the large bowel.

Effects of Blacklight Trap Design and Placement on Catch of Adult Hickory Shuckworms13

Seventeen comparisons of blacklight traps were made to determine the effects of trap components, ultraviolet output, killing agents, and trap placement on captures of Laspeyresia caryana (Fitch) moths, and on the total weight of all insects caught. Placement of traps dose to the fruiting area of a pecan tree was found to be the most important consideration, but catches of L. caryana were increased by increases in total output of ultraviolet radiation. Baffles on the trap did not aid in the catch of L. caryana and may increase the catch of unwanted insects. The closeness of the lamp to the collecting funnel appeared to be important, but an increase in the funnel diameter was of minor importance.

Directional flow of fallopian tube secretion in the Romney ewe.

The continuous collection of fluid flowing from both ends of the Fallopian tube of the ewe was attempted by placing a cannula in the ovarian end of the ampulla and a further cannula passing through the wall of the corresponding uterine horn and opposed to the uterotubal junction. Daily recordings of fluid were made in thirty ewes over a period ranging from 3 to 106 days; observations were also made for oestrous behaviour. There was an increase in total output of tubal fluid starting on the last day of the oestrous cycle and reaching a maximum about Day 2, after which a gradual decline occurred. A greater part of the total fluid secreted flowed through the ampullar end. Flow through the utero-tubal junction into the uterus remained low for most of the cycle, but markedly increased in all cycles 3\m=.\9\m=+-\0\m=.\1days after the onset of oestrus. The peak flow through the utero-tubal junction would therefore appear to coincide with the time during which ova enter the uterus in the ewe.

Technical Change in Corn Production in the United States, 1870-1960

tion techniques explains most of the measured increase in total output in the United States, and the declining relative prices of agricultural products reflect lower unit costs of production. Nevertheless, evaluation of the contribution of specific changes in techniques toward total economic growth has been seriously neglected. Because success in raising incomes in the poorer countries will depend mainly on the rate at which economic changes can be achieved, it is urgent that the economic implications of competing technical changes be understood and that the consequences of alternative timing and sequence patterns of adoption be more fully considered. The aim of this paper is to reexamine the evidence on resource use as well as that on technical changes attending the great increase in corn production in the United States over the past century. Viewed in its relation to the total economy, a principal product of the agricultural sector is energy. Food and feed grains, hay and pasture, as well as other crops, constitute the basic energy sources. Some are directly usable for human consumption, but may be converted into draft power by animals, or into the more costly meat and dairy products. It seems evident that achieving ability to produce such energy cheaply is one kind of economic growth that permits more growth; technical change * This paper is a contribution from the Project on Causes of Increased Productiv.ity in American Agriculture directed by Karl Brandt and supported by the Relmhn Foundation. We are also indebted to our colleague R. J. Hammond for critical discussions of the argument and suggestions that helped to improve the clarity of exposition.

Neutrality of Technical Progress

Technical Change R ECENT studies have attempted to derive the relative proportions of total increase in output that are caused by growth in capital stock and by technical advance. These studies seem to have turned attention away from capital formation as a source of growth to technical change as the only important factor. Each of these papers has assumed, explicitly or implicitly, that the technical change takes place in a neutral fashion. The present paper examines this assumption and finds it to be questionable. In this light, new estimates of the importance of capital formation are found. The first important recent paper attempting to measure technical change was presented by Robert Solow.' He concluded that technical change is neutral on the average, that there was little basis of choice with his data among five possible production functions, and that about 87?2 per cent of the increase in gross output per man hour is attributable to technical change, and I2/2 per cent to increased use of capital. Other authors with various techniques have studied the relative importance of capital and of technical progress. Niitamo made a regression model of production in Finland and found most of the increase was attributable to the passage of time and to education, and little was attributable to capital formation.2 He concluded that emphasis should be taken away from capital as an aid to economic growth and placed instead on these other factors which he lumped together as the human factor. Massell made a study with improved data that used the same methods as Solow but which annlied only to the manufacturing sector.3 His results again gave the greatest importance to technical change. He said,

Uncertainty, Learning, and the Economics of Parallel Research and Development Efforts

IN recent years, there has been a very marked rise in the interest economists have shown in the process of invention, and in industrial Research and Development the institutionalization of inventive activities by business enterprises. developing interest in invention has stemmed from several roots. One important one is the growing body of research findings on productivity,' which turned the attention of economists interested in economic growth toward the process of technological change. These studies showed that only a small fraction of the total increase in output per worker which had occurred in the American economy since the late igth century could be explained by capital per worker. lion's share had to be attributed to something else, to or efficiency. term increased productivity covers a wide number of different elements and the operation by which is defined and measured obscures a variety of economic phenomena. Better allocation of existing factor supplies (the process of dynamic adjustment) and capital formation in humans (education, health, etc.) are two of the most important. But it seems obvious that technological change also has been an important ingredient. A second source of the interest in invention is the changing way that economists are coming to look at the competitive process. Increasingly the focus is on competition through new products, rather than on direct price competition. And concurrently, normative considerations are shifting toward conditions of long run growth rather than fixing on short term Pareto optimality. In a sense these developments represent a renaissance of Schumpeter. A third source of the heightened interest in inventive activity has been the cold war, and the growing awareness that our national security may depend on the output of our military research and development effort organized inventive effort for the purpose of creating more effective weapons. Closely related to the interest in military R and D 2 is the growing concern with the technological race to which the Soviets have challenged us. interest in inventive activity which stems from interest in defense and the space program has tended to be more micro-oriented than the interest stemming from concern with problems of economic growth. studies generated have tended to be normative analyses of conditions of efficiency (how resources should be allocated), rather than analyses of factors determining the actual allocation of inventive effort. This paper is focused on one aspect of R and D efficiency: the problem of achieving a given objective at minimum cost. Thus the paper is directly concerned with the third area of interest discussed above. However, some of the implications of the model seem to have relevance to more macro issues of policy, and to a positive analysis of the allocation of inventive effort. In Section I, the basic efficiency problem is discussed and the concept of a parallel path strategy is introduced. Section II presents a model. Lest the reader expect too much, let me state at the outset that the model is much too crude to provide reliable quantitative answers. Rather, the purpose of the model is to provide a framework for analysis and to explore some implications of two aspects of the R and D nrocess. the uncertaintv which exists * This paper is one product of a continuing RAND study of Research and Development management. idea of a parallel development strategy has a long history at RAND. Burton Klein, William Meckling, Emmanuel Mesthene, Leland Johnson, Thomas Marschak, Armen Alchian, William Capron, and others all have contributed to its evolution. ' See, for example: J. Schmookler, The Changing Efficiency of the American Economy, I869--I934, this REVIEW, XXXIV (Aug. I952); M. Abramowitz, Resource and Output Trends in the United States since I870, American Economic Review, XLVI (May I956); Robert Solow, Technical Change and the Associate Production Function, this REVIEW, XXXIX (Aug. I957); B. F. Massell, Capital Formation and Technological Change in United States' Manufacturing, this REVIEW, XLII (May I960). 2 Research and Development will henceforth be abbreviated as R and D.

Fluctuations et croissance économique en France (1820-1952)

<i>Economic growth and fluctuations in France 1820-1952 </i> This study sets out to analyse the growth of the french economy over a period of 130 years by presenting, as far as available statistical material allows, continuous, or comparable time series. The major task has been to construct satisfactory indices for the pre-1914 period. The material already published by the I.S.E.A. has been used, but the author has endeavoured to give deflated total production figures. Various cross-checks have also been provided by the addition of the available statistical material for certain sectors of economic activity. In particular, time series on coal production and imports, iron and steel output and transports, both inland and maritime, have been constructed. The author considers two types of trend-production capacity and output. The concept of productive capacity is applied here for the first time to long-term trends derived from french pre-1914 data. Finally, the author considers the political implications of the fact that, down to 1913, and, to some extent until 1930, despite marked instability in output, increases in production were sufficient to give all social groups, in each generation, an increased real volume of consumption. On the contrary, from 1930 to 1952, an increase in total output was not available and, as a result, one social group could only increase its consumption at the expense of others.

The use of procaine penicillin in the production of table poultry under practical conditions in the united kingdom

AbstractProcaine penicillin (procaine benzylpenicillin) given from the first day after hatching to slaughter led to a total increase in output of 11 and 15.4% respectively in two trials on different strains of table cockerels. The improved yield was partly due to improved growth and partly to a reduction in cull rate. Penicillin improved food‐conversion up to seven weeks of age, but this advantage was no longer evident at 15 weeks.

Response of the Left Ventricle to Changes in Output

Previous studies on the mammalian heart have demonstrated that both the diastolic and systolic volumes increase with an increase in total output, mean arterial pressure remaining constant. (Patterson, Piper and Starling, Wiggers and Katz). Kozawa, working with the turtle's heart found that only the diastolic volume varied. The present study was made on dogs using the modified heart lung preparation of Dusser de Barenne in conjunction with an apparatus designed to maintain physical conditions as constant as possible regardless of variations in output. A cannula of large diameter was inserted into the aorta. The pulmonary artery was cannulated twice, one cannula toward the right ventricle and the other toward the lungs. The right ventricle pumped only blood flowing from the coronary system, while the left ventricle that which was allowed to return from the venous reservoir. Fig. 1 shows the result obtained by rapidly increasing the input to the left ventricle. The changes in volume of the ventricles, were recorded so that systole produced a downward movement of the piston-recorder lever. Prior to (1) no blood was returning to the left ventricle from the venous reservoir, the right ventricle pumping only the coronary blood flow. At (1) blood from the venous reservoir was allowed to return to the left ventricle by way of the lungs. The diastolic volume rapidly increased to a plateau at (6). The systolic volume decreased with one exception to (2). From (3) to (4) the output of the left ventricle was about 1000 cc. per minute. The venous return to the left ventricle was blocked at (4). At (5) the volume changes of the heart were again approximately the same as at (1). Heart rate was constant and mean blood pressure increased only about one mm. Hg. during the peak of the flow, as indicated at (4).