Human Health Risk Assessment of Penicillin/Aminopenicillin Resistance in Enterococci Due to Penicillin Use in Food Animals

Penicillin and ampicillin drugs are approved for use in food animals in the United States to treat, control, and prevent diseases, and penicillin is approved for use to improve growth rates in pigs and poultry. This article considers the possibility that such uses might increase the incidence of ampicillin-resistant Enterococcus faecium (AREF) of animal origin in human infections, leading to increased hospitalization and mortality due to reduced response to ampicillin or penicillin. We assess the risks from continued use of penicillin-based drugs in food animals in the United States, using several assumptions to overcome current scientific uncertainties and data gaps. Multiplying the total at-risk population of intensive care unit (ICU) patients by a series of estimated factors suggests that not more than 0.04 excess mortalities per year (under conservative assumptions) to 0.14 excess mortalities per year (under very conservative assumptions) might be prevented in the whole U.S. population if current use of penicillin drugs in food animals were discontinued and if this successfully reduced the prevalence of AREF infections among ICU patients. These calculations suggest that current penicillin usage in food animals in the United States presents very low (possibly zero) human health risks.     

Urban forest cover of the Chicago region and its relation to household density and income

Urban forests and herbaceous open space play a vital role in the environmental and aesthetic health of cities, yet they are rarely identified in land-use inventories of urban areas. To provide information on urban forests and other vegetative land cover in Illinois cities, Landsat Thematic Mapper (TM) data from June 27, 1988, were classified for the Chicago metropolitan region (9,717 km²). Ten land-cover classes were identified, including two types of forestland (occupying 5.8% of the total area), residential land with trees (14.6%) or without trees (7.8%), cropland (37.5%), two types of grassland (7.7%), urban with impervious surfaces (23.1%), water (1.6%), and miscellaneous vegetation (2.1%). Correlation analyses indicated that household income and household density are strongly related to land covers in the region, particularly those with tree cover and urbanized land. Population changes for 1980–1985 and 1985–2010 (projected) show a pattern of increasing density in the urbanized zone concurrent with continued urban sprawl, primarily into current cropland.     

Social theory and the de-escalation of international conflict*

Are we like the mothers and fathers at Jonestown, with the cyanide in place, rehearsing for suicide-murder? Daniel Ellsberg (1981) observes that the marchers protesting nuclear weapons are doing what the mothers and fathers in Jonestown waited too long to say ‘No! Not our children! This is craziness; we won't be part of it.’ He writes that ‘It is none too soon to be saying this to the President/Prime Minister/Chairman Jim Jones's of the world; nor is it, yet, too late.’ How did we get into a place that even resembles Jonestown: And more importantly, how do we get out of it? Social theory should help provide answers to such questions, but does not obviously do so. In the first part of this paper I discuss an emerging theoretical paradigm that has particular relevance for understanding how international conflicts increase and decrease in intensity. Then I apply that paradigm to instances of international conflict de-escalation, focusing on declines in tension and hostility between the Soviet and American governments and the Israeli and Egyptian governments. Finally, I will point to some implications of the discussion for social theory and for international policy.     

Community Control,Community Mobilization,and Community Political Structure in 57 U. S. Cities*

This paper describes the results of a comparative study of the factors which inhibited or facilitated the development of the issue of community control of schools in fifty-seven cities in the United States. The findings suggest that the degree to which blacks and the poor were mobilized for political action and the political characteristics of the city were important in determining whether or not the issue entered the political arena.     

On the multivariate structure of wellbeing

A mapping sentence is provided for defining the universe of observations of wellbeing. According to this, assessment of wellbeing is attitudinal. Data from several studies verify that the First Law of Attitude holds for wellbeing. These data also show the structure of the interrelationships among the variables to be that of intermeshing cylindrexes, in an SSA space of four dimensions. Areas of life play the role of polarizing facets, while self-versus-community and situation-versus-treatment serve as axial facets. Modulating facets include primary-to-secondary interaction, and generality-to-specificity.     

A Comparative Analysis of Propositions Describing Social Movement Organizations*

Natural history, observational, and interview data from a study of two anti-pornography crusades and the social movement organizations which created and directed them are used to assess nine propositions formulated by Zald and Ash (1966) concerning the structure and dynamics of social movement organizations. The Zald-Ash propositions were formulated from the literature on national, established social movement organizations. This paper explores the applicability of the propositions to those organizations which are small and emerging. The propositions are generally supported. Discrepancies are accounted for by the significant influence of leadership orientation, goal specificity, and incentive structure in determining other structural and dynamic characteristics of small or emerging social movement organizations.     

Stable matching problems with exchange restrictions

We study variants of classical stable matching problems in which there is an additional requirement for a stable matching, namely that there should not be two participants who would prefer to exchange partners. The problem is motivated by the experience of real-world medical matching schemes that use stable matchings, where cases have arisen in which two participants discovered that each of them would prefer the other’s allocation, a situation that is seen as unfair. Our main result is that the problem of deciding whether an instance of the classical stable marriage problem admits a stable matching, with the additional property that no two men would prefer to exchange partners, is NP-complete. This implies a similar result for more general problems, such as the hospitals/residents problem, the many-to-one extension of stable marriage. Unlike previous NP-hardness results for variants of stable marriage, the proof exploits the powerful algebraic structure underlying the set of all stable matchings. In practical matching schemes, however, applicants’ preference lists are typically of short fixed length, and we describe a linear time algorithm for the problem in the special case where all of the men’s preference lists are of length ≤3.     

An Exposure‐Response Threshold for Lung Diseases and Lung Cancer Caused by Crystalline Silica

Whether crystalline silica (CS) exposure increases risk of lung cancer in humans without silicosis, and, if so, whether the exposure‐response relation has a threshold, have been much debated. Epidemiological evidence is ambiguous and conflicting. Experimental data show that high levels of CS cause lung cancer in rats, although not in other species, including mice, guinea pigs, or hamsters; but the relevance of such animal data to humans has been uncertain. This article applies recent insights into the toxicology of lung diseases caused by poorly soluble particles (PSPs), and by CS in particular, to model the exposure‐response relation between CS and risk of lung pathologies such as chronic inflammation, silicosis, fibrosis, and lung cancer. An inflammatory mode of action is described, having substantial empirical support, in which exposure increases alveolar macrophages and neutrophils in the alveolar epithelium, leading to increased reactive oxygen species (ROS) and nitrogen species (RNS), pro‐inflammatory mediators such as TNF‐alpha, and eventual damage to lung tissue and epithelial hyperplasia, resulting in fibrosis and increased lung cancer risk among silicotics. This mode of action involves several positive feedback loops. Exposures that increase the gain factors around such loops can create a disease state with elevated levels of ROS, TNF‐alpha, TGF‐beta, alveolar macrophages, and neutrophils. This mechanism implies a “tipping point” threshold for the exposure‐response relation. Applying this new model to epidemiological data, we conclude that current permissible exposure levels, on the order of 0.1 mg/m³, are probably below the threshold for triggering lung diseases in humans.     

Why a time effect often has a limited impact on capture‐recapture estimates in closed populations

The author is concerned with log‐linear estimators of the size N of a population in a capture‐recapture experiment featuring heterogeneity in the individual capture probabilities and a time effect. He also considers models where the first capture influences the probability of subsequent captures. He derives several results from a new inequality associated with a dispersive ordering for discrete random variables. He shows that in a log‐linear model with inter‐individual heterogeneity, the estimator N is an increasing function of the heterogeneity parameter. He also shows that the inclusion of a time effect in the capture probabilities decreases N in models without heterogeneity. He further argues that a model featuring heterogeneity can accommodate a time effect through a small change in the heterogeneity parameter. He demonstrates these results using an inequality for the estimators of the heterogeneity parameters and illustrates them in a Monte Carlo experiment