The Social ecology of Madrid: Stratification in comparative perspective

This paper examines the characteristics of residential zones in Madrid, Spain. The primary difference between zones is found to lie in a new bourgeoisie life-style dimension. Working women are found to be the best indicator of this dimension, which also involves servants, natives of Madrid and high degrees of literacy. Fertility-related considerations, however, are unrelated to working women, and this is explained as due to the availability of domestic help and "women-oriented" working arrangements. Fertility and socioeconomic status are found to be interrelated and constitute a second dimension of residential segregation. In conclusion, Madrid is examined in relation to both more and less industrialized cities, leading to a further modification of social area theory contentions concerning the ecology of stratification in developing cities.     

The coevolution of population and environment: The ecology and ideology of feedback relations in Pakistan

A new approach to the study of population and environment is proposed, based on Norgaard's theory of co-evolution. This theory is applied to two developments currently underway in Pakistan: the transfer of tree cover from public forests to private farms, and the partial replacement of woodfuel by dungfuel in household hearths. Both developments are characterized by feedback from the ecosystem to the sociosystem, which consists of a shift of regulatory mechanisms and complexity from the former to the latter. The efficacy of this feedback depends on an accurate perception of the process by the participating population. These perceptions are more accurate in the case of the forest-farm transition than the woodfuel-dungfuel transition, and this explains why the latter appears less sustainable than the former. Accuracy of perception also varies systematically between government officials and local peoples, primarily due to openness to explanations of behavior based on population/resource pressure. It is concluded that external development agencies have a potentially important role to play in demystifying perception of feedback processes between ecosystem and sociosystem.     

Frontiers in population ecology of microtine rodents: A pluralistic approach to the study of population ecology

Current challenges for the study of population ecology of microtine rodents are reviewed. Comparisons with other taxonomic groups (other mammals, birds and insects) are given throughout. A major challenge is to link patterns and processes (i.e. mechanisms) better than is the case today. Other major challenges include the furthering of our understanding of the interaction between deterministic and stochastic processes, and as part thereof, the interaction between density-dependent and density-independent processes. The applicability of comparative studies on populations exhibiting different temporal dynamical patterns is, in this connection, emphasized. Understanding spatiotemporal dynamical patterns is another major challenge, not the least from a methodological point of view. Long-term and large-scale ecological data on population dynamics (in space and time) are critical for this purpose. Looking for consistency between hypothesized mechanisms and observed patterns is emphasized as a good platform for further empirical and theoretical work. The intellectual feedback process between different approaches to the study of microtine population ecology (observational studies, experimental manipulative studies, statistical modeling and mathematical modeling) are discussed. We recommend a pluralistic approach (involving both observational and experimental as well as theoretical studies) to the study of small rodent ecology.     

Emerging issues in urban ecology: implications for research,social justice,human health,and well-being

Urbanization affects landscape structure and the overall human condition in numerous ways. Green spaces include vegetated land cover (e.g., urban forests, trees, riparian zones, parks) which play a distinctive role in urban ecology. This article reviews emergent literature on the linkages between urban green spaces, social justice, and human health. We explore this subject in the context of landscape structure, ecosystem services, and distributional equity as it relates to various health outcomes. Finally, we conclude by identifying gaps in the scholarship and potential areas of future research.     

The ecology of race and socioeconomic distress: infant and working-age mortality in Chicago

We examine the effects of education, unemployment, and racial segregation on age-, sex-, and race-specific mortality rates in racially defined Chicago community areas from 1989 to 1991. Community socioeconomic factors account for large observed areal variations in infant and working-age mortality, but especially working-age mortality for the black population. For black men, the mortality consequences of living in economically distressed communities are quite severe. Segregation effects on mortality are more modest and largely operate through neighborhood socioeconomic conditions, although some direct effects of segregation on mortality for blacks are apparent.     

农村人口流动对农田生态建设的影响

本文从我国实际出发,分析了农村剩余劳动力流出及其回流对农田生态建设的影响,趋利避害,因势利导,为新形势下我国农田生态建设提出相应的建议,以期为我国经济建设提供良好的生态环境支持和强大的经济动力。     

天山北坡经济带人与自然生态协调发展的实证分析

作为可持续发展的重要组成部分,人与自然生态的协调发展意义重大。作为新疆经济最发达的地区之一,天山北坡经济带中人与自然生态的发展状况处于何种阶段,不协调的因素有哪些,是否能适应可持续发展的要求,近来成为经济学家探讨的热门话题。本文从人口、资源、环境三个系统间的协调程度入手,借助历史数据,运用协调系数法和主成分分析法对天山北坡经济带人与自然生态的协调发展进行实证分析。     

Economics,ecology and entropy: The second law of thermodynamics and the limits to growth

The second law of thermodynamics has played an important role in ecological economics as providing a justification for the view that economies have limits to growth. Yet beyond basic textbooks statements of this law, we seldom find informed philosophical examinations of the meaning and metaphysical justification for the second law. In this paper we shall examine some challenges which have been made to the limits to growth (Limitationist) position by those criticizing the scope and application of the second law of thermodynamics and we shall in turn defend Limitationism against these criticisms.     

Emergent and effective properties in ecology and evolution

Emergent properties are often discussed in arguments concerning relationships among different levels. However, the different definitions of emergent properties sometimes confuse the arguments about macro-level phenomena, since some authors regard emergent properties not only as observable global patterns but as properties that affect and cause change in ecological and evolutionary processes. Thus it is important to distinguish higher-level or larger-scale properties that can influence particular ecological and evolutionary processes from those that cannot. I call the former properties effective properties. I gave examples that show why the distinctions between effective and non-effective properties are important.     

Factorial ecology: A critique and some suggestions

Studies in factorial ecology have typically used the principal factor procedure coupled with varimax rotation. Since it can be shown that the results one obtains vary according to the factor and rotation models he employs, and since there is no one “best” way of obtaining initial and derived factor solutions, it is proposed that future research in the area adopt an approach involving the simultaneous use of several different computing algorithms for obtaining initial solutions and both orthogonal and oblique rotation procedures to avoid the possibility that the results one obtains are not method-dependent. Ideally, the factor models employed should differ maximally with respect to the principles upon which they are based. If one finds a given factor regardless of the method he uses, only then can he assert with any confidencethat it is not an artifact of his method. Factorial ecologists are often interested in computing “factor scores”, but “true” factor scores are not uniquely computable; they can only be estimated. Since the proposed research strategy involves using either a component or an image model, in which the corresponding scores are exact and uniquely computable, the factor score problem is, in a sense, solved. Next it is suggested that, by using orthogonal solutions, factorial ecologists may be overlooking a very important piece of information—the correlation between the factors. There is some reason to believe that this varies from city to city, and may account for the fact that some factors which emerge in studies of Western cities are sometimes not found in cities elsewhere. Some comments are also made on the value of using census tract data, and on the availability of computer programs for different initial and derived factor solutions.     

The length of the human fertile period

Abstract Estimates of the. length of the human fertile period (that interval within the menstrual cycle during which insemination is associated with a non-zero probability of conception) are necessarily indirect. Moreover, those estimates do not seem in close agreement with one another. For instance, it has been suggested that:     

The length of the human fertile period

Estimates of the. length of the human fertile period (that interval within the menstrual cycle during which insemination is associated with a non-zero probability of conception) are necessarily indirect. Moreover, those estimates do not seem in close agreement with one another. For instance, it has been suggested that:     

The effects of temperature on human fertility

Monthly birth and temperature data for a variety of states and countries are used to estimate the effect of short-run temperature fluctuations on fertility. Regressions of monthly births on a flexible specification of lagged monthly temperature show that temperature has quantitatively important effects on both seasonal and nonseasonal variation in births. Summer temperature extremes reduce conceptions in the southern United States, explaining a substantial part of the observed seasonal birth pattern. Extreme cold shows no evidence of affecting conceptions. The results also show significant seasonality in births even after accounting for temperature. Controls for monthly temperature do not explain the persistent spring peak in births in northern Europe. This finding suggests that other factors play an important role.     

Incorporating physiology into parasitoid behavioral ecology: the allocation of nutritional resources

A critical problem faced by most theoretical studies of parasitoid behavior and population dynamics has been the paucity of empirically obtained information about the pattern of resource allocation to egg production and metabolic maintenance in relation to adult diet in female parasitoids. This review calls for a shift from traditional manipulative feeding studies to studies that quantify the energetic budget of parasitoids and which take into account the dynamic nature of metabolic processes. As guidelines, we highlight the advances made along these lines with other insect groups and some of the simplest tools already available today for fulfilling this goal. Received: December 22, 1998 / Accepted: January 12, 1999     

Urban dominance,ecology and community well-being in a Philippine region

There is a strong difference of opinion concerning whether the effects of urban centers are generally beneficial or deleterious to outlying communities. Based on a sample of seventy-three barrios in Cavite Province, this paper examines several basic features of community organization to determine what effects Manila's dominance exerts. The Manila-Cavite metropolitan region is further complicated by a pronounced highland—lowland division. Land tenure, occupational structure, political activity, indebtedness, and measures of community well-being give evidence of both positive and negative effects. However, Manila's dominance does not correspond to uniform gradient patterns. Due to sharp ecological differences, the impact of the city varies between highland and lowland barrios. The fairest conclusion able to be drawn from the evidence is that contact with the city is indispensible and in many ways beneficial, but these benefits are often counterbalanced by economic and social costs for certain communities.     

The effect of emigration on human capital formation

This paper focuses on a possible effect of emigration on human capital formation. Emigration to a higher returns to skill country provides an incentive to invest in human capital. The level of human capital formation in the source country can therefore be positively correlated with the probability of emigration. Incidentally a surge in emigration can lead the source country out of an under-development trap. The implications of the model for the convergence controversy are also discussed. Received: 16 July 1997/Accepted: 28 July 1998