Promote Population Growth Research Articles

THE EFFECT OF TWO ORGANIC AMENDMENTS AND Trichoderma spp. TO CONTROL Sclerotinia spp. IN LETTUCE

The effect of organic matter contained in a biosolid and chicken manure on the establishment and performance of Trichoderma spp. used as biocontrol agents against Sclerotinia spp. in lettuce (Lactuca sativa L. cv. Buba) was evaluated. Population dynamics of Trichoderma spp. was evaluated by the method of counting colony forming units on plaques of Potato-Dextrose-Agar (PDA), and its efficiency to control the disease was measured by visual assessment of the degree of crop damage by Sclerotinia spp. Statistically significant differences observed in population dynamics of Trichoderma spp. were attributed to the influence of the source of the organic matter. The biocontrol agent Trichoderma lignorum was able to use the organic matter of the biosolid and in situ organic matter. Poultry manure and the biosolid were not efficient enough to promote population growth of native Trichoderma species. The damage caused by Sclerotinia spp. was statistically similar in all treatments and less than 25 %, so that the efficiency of T. lignorum and T. harzianum to control the pathogen was proven.

Integrated water resources management in the Luquillo mountains, Puerto Rico: an evolving process

The ecologically unique forest ecosystems of the Luquillo Mountains in Eastern Puerto Rico and the scenic value of its forests, rivers and surrounding beaches have promoted population growth, tourism and light industry, thus increasing regional water demands. In light of further increases in future water demand, integrated water resources management (IWRM) initiatives are rapidly evolving in this area. In an effort to seek international collaboration and information exchange on IWRM, the Luquillo Mountains joined the Hydrology for the Environment, Life, and Policy (HELP) Programme of the United Nations Educational, Scientific, and Cultural Organization (UNESCO)/International Hydrological Programme (IHP) in 1999. This paper was prepared to document existing IWRM efforts and to promote internal discussion for further IWRM development in the region.

Promotion of the Population Growth of Pinewood Nematode in 4-month-old Japanese Black Pine Seedlings by Pretreatment with Simulated Acid Rain

Simulated acid rain (SAR) at three pH levels (pH 4, 3, 2) was applied to only the top or both the top and roots of 4-month-old Japanese black pine seedlings repeatedly for two months. Then the seedlings were inoculated with a virulent isolate (S10) of pinewood nematode, Bursaphelenchus xylophilus. The exposure to SAR at any level did not kill the seedlings. When inoculated with nematodes, however, the nematode population build-up was significantly higher in the seedlings pretreated with SAR at any level than in the control at the 7th and 17th day after inoculation, and subsequent disease symptom development was also significantly accelerated by the exposure to SAR at pH 2 and 3. This result indicates that even acid rain at pH 4 has the potential for promoting population growth of pinewood nematodes in 4-month-old Japanese black pine seedlings.

Growth, population, and knowledge diffusion

This paper reviews the recent development of growth theory, focusing on the consistency between theory and evidence in terms of effects of population on growth, and presents some policy implications. Although positive effects of the population size on growth are likely to exist, the size does not necessarily mean the size of the domestic population. In the world with substantial but costly international knowledge diffusion, what affects growth is the population size of the technological leader country, the United States, from which knowledge spills over, and it is the world population when diffusion is costless. Therefore, policies to promote population growth may not be growth-enhancing for most advanced countries. A more effective population-related policy objective theoretically suggested is to encourage international knowledge diffusion.

Demographic and genetic invasion history of a 9-year-old roadside population of Bunias orientalis L. (Brassicaceae).

The population history of a 9-year-old roadside population of the invasive plant Bunias orientalis was reconstructed by demographic analysis including size, position, age (determined by herbchronology) and RAPD-PCR patterns of individual plants. We evaluated emerging patterns of population growth and genetic structure during a full period of population development under typical site conditions (anthropogenic disturbance) and their possible consequences for the invasion potential of the species. The population has grown rapidly and continuously (though with slowing geometric population increase) during the 9 years since its foundation, filling the space available in the study area. Genetic variation (RAPD markers) was already high in the founder cohorts and remained at the same level throughout population development (variance fluctuations <15%). Both results may be related to the mowing management at the site which seems to promote population growth of B. orientalis relative to other co-occuring species and to prevent the genetic drift and the development of spatial genetic structure that would be expected under isolation-by-distance models. Large founder plants had comparatively low genetic variance and were more closely related to younger cohorts than were small founder plants, indicating that selection acted during population development. Overall, the current anthropogenic disturbance regimes may contribute to high genetic variability by artificially increasing gene flow and thereby promoting the adaptability of invasive species to the often unpredictable conditions at disturbed sites. Our approach using retrospective demographic investigation allows the detection of spatio-temporal microscale patterns in genetic and phenotypic variation. Thus it allows a thorough understanding of local invasions of perennial herbaceous plants.

Community, Capitalism, and Rebellion in Chiapas

In this paper, we examine the role of local land tenure, community solidarity, and recent commercialization in the 1994 rebellion in Chiapas. We find that neither the ejido land tenure system, nor community solidarity, nor community disruption and proletarianization due to recent economic change, may be considered as primary causal factors behind the revolt. We find the best explanation for the revolt to lie in the desire of certain groups, notably immigrants to the Lacondón rain forest area, for land, and in recent changes in land tenure law which have ended their hopes of acquiring land. The primary effect of economic change was indirect. It promoted population growth, which has led to increasing pressure on land.

Was low atmospheric CO2 during the Pleistocene a limiting factor for the origin of agriculture?

AbstractAgriculture originated independently in many distinct regions at approximately the same time in human history. This synchrony in agricultural origins indicates that a global factor may have controlled the timing of the transition from foraging to food‐producing economies. The global factor may have been a rise in atmospheric CO2 from below 200 to near 270 μol mol−1 which occurred between 15,000 and 12,000 years ago. Atmospheric CO2 directly affects photosynthesis and plant productivity, with the largest proportional responses occurring below the current level of 350 μol mol−1. In the late Pleistocene, CO2 levels near 200 μol mol−1 may have been too low to support the level of productivity required for successful establishment of agriculture. Recent studies demonstrate that atmospheric CO2 increase from 200 to 270 μol mol−1 stimulates photosynthesis and biomass productivity of C3 plants by 25% to 50%, and greatly increases the performance of C3 plants relative to weedy C4 competitors. Rising CO2 also stimulates biological nitrogen fixation and enhances the capacity of plants to obtain limiting resources such as water and mineral nutrients. These results indicate that increases in productivity following the late Pleistocene rise in CO2 may have been substantial enough to have affected human subsistence patterns in ways that promoted the development of agriculture. Increasing CO2 may have simply removed a productivity barrier to successful domestication and cultivation of plants. Through effects on ecosystem productivity, rising CO2 may also have been a catalyst for agricultural origins by promoting population growth, sedentism, and novel social relationships that in turn led to domestication and cultivation of preferred plant resources.

Ethics of family planning

The expression, “ethics of family planning,” it is argued, has no firm meaning, and should not be taken to imply that a full set of moral rules and principles governing family planning has been or is likely to be established. A survey is made of recent views on population and economic and social development, and it is argued that, although there is, indeed, no “universal problem” of population, the optimistic — as well as the pessimistic — view of this relationship is open to doubt. It is further argued that “ethics” cannot be imposed on subject matter of population from without: The very identification of a “problem” of population is evaluative from the start. A scheme of analysis to appraise the ethical status of measures to arrest or promote population growth is proposed, and a number of such measures are critically analyzed.

The European Parliament on the Need for Promoting Population Growth

The European Parliament on the Need for Promoting Population Growth

Community Power and Population Increase: An Empirical Test of the Growth Machine Model

Attempts to relate community power to policy outputs have been criticized for lacking theoretical relevance and statistical significance. To overcome these criticisms, this research employs a power-policy model based on a political economy framework which utilizes Molotch's conpetion of the community as a growth machine. Analysis of the Permanent Community Sample provides strong power-policy relationships that support the major tenets of the growth machine explanation: As members of the business elite gain power, they can successfully promote population growth that provides them with greater profits through higher property values. The most widely cited common good for growth, lower unemployment, does not accrue. This supports the relevance of a political economy approach to community phenomena and suggests different directions for community power research.

Mexico's Population Policy Turnaround

Until 1972 Mexico's officials seemed to believe that the annual population growth rate of 3.5% was not really a problem as long as the economic development rate could be kept ahead of the population growth rate. The General Law of Population of 1947 was actually promoting population growth. It was only during the 1960s that elite opinion shifted, and privately funded family planning programs became increasingly active. By 1972 the population had reached 54 million, from 20 million in 1940. President Echevarria, till then a traditional pronatalist, announced in 1972 the creation of a national family planning program, and, in 1974, the creation of a national population council. Since then the Mexican government has embarked on ambitious programs of mass communication and sex education to make the population receptive to its new attitudes. The plans have worked: by mid-1979 estimates put the population growth rate at 2.9%, within sight of the 2.5% target set for 1982 by new president Lopez Portillo. According to a survey conducted by the National Fertility Survey, by late 1976 41.50% of Mexican women of childbearing age were practicing contraception. Within the 41.50% of active contraceptors, 14.9% use the pill, and 7.8% the IUD. New channels of information and of contraceptive delivery are being explored to reach Mexico's widely scattered rural population, and to bring the average family size down to 2 children from the average of 6.5 children per woman for 1973-1975. The government goal is of a 1% population increase by the year 2000.

CONTRASTS IN COMMUNITY ACTION AND OPINION1

ABSTRACT. Opinion or attitude surveys and observations of people's actions are complementary research tools, but they often provide different results. This was the case where two communities, one rural, one suburban, made waste water management decisions which would promote population growth while survey data indicated that community attitudes were neutral or slightly opposed to population growth. Observation of action, and expanding the range of survey response variation revealed that the structure of both community opinion and action was primarily influenced by small groups of people with very strong feelings favoring and disfavoring population growth. Those with very strong feelings were the ones observed to be acting to promote or retard growth.

Mathematical analysis of the asymptotic behavior of the Leslie population matrix model.

Let L be a Leslie population matrix. Leslie (1945) and others have shown that the matrix L has a leading positive eigenvalue λ0 and that in general: lim ⁡ t → ∞ L t X λ 0 t = γ X λ 0 , ( 1 ) where X λ 0 is an eigenvector corresponding to λ0, X is any initial population vector, and γ is a scalar quantity determined by X. In this article we generalize (1) exhaustively by removing the mild restrictions on the fertility rates which most writers impose. The result is an oscillatory limit of a kind first noted by Bernardelli (1941) and Lewis (1942) and described by Bernardelli as “population waves”. We calculate in terms of λ0 and the entries of the matrix L the values of this oscillatory limit as well as its time-independent average over one period. This calculation includes as its leading special case the result of (1), confirming incidentally that γ is non-zero. To stabilize a population, the matrix L must be adjusted so that λ0 = 1. The limits calculated for the oscillatory and non-oscillatory cases then have maximum significance since they represent the limiting population vectors. We discuss a simple scheme for accomplishing stabilization which yields as a byproduct an easily accessible scalar measure of L's tendency to promote population growth. The reciprocal of this measure is the familiar net reproduction rate.

The Poor Law Report Reexamined

In an earlier article, I pleaded for a reappraisal of the Old Poor Law. Despite what all the books say, the evidence that we have does not suggest that the English Poor Law as it operated before its amendment in 1834 reduced the efficiency of agricultural workers, promoted population growth, lowered wages, depressed rents, destroyed yeomanry, and compounded the burden on ratepayers. Beyond this purely negative argument, I tried to show that the Old Poor Law was essentially a device for dealing with the problems of structural unemployment and substandard wages in the lagging rural sector of a rapidly growing but still underdeveloped economy. It constituted, so to speak, “a welfare state in miniature,” combining elements of wage-escalation, family allowances, unemployment compensation, and public works, all of which were administered and financed on a local level. Far from having an inhibitory effect, it probably contributed to economic expansion. At any rate, from the economic point of view, things were much the same after 1834 as before. The Poor Laws Amendment Act of 1834 marked a revolution in British social administration, but it left the structure of relief policy substantially unchanged.