Leibholz: Politics and Law

A Review of Politics and Law by Gerhard Leibhol

Kaiser: Planung I-Recht und Politik der Planung in Wirtschaft und Gesellschaft

A Review of Planung I-Recht und Politik der Planung in Wirtschaft und Gesellschaft edited by Joseph H. Kaise

Negative magnetic susceptibility and nonequivalent ensembles for the mean-field ϕ4\phi^4 spin model

We calculate the thermodynamic entropy of the mean-field $\phi^4$ spin model in the microcanonical ensemble as a function of the energy and magnetization of the model. The entropy and its derivative are obtained from the theory of large deviations, as well as from Rugh's microcanonical formalism, which is implemented by computing averages of suitable observables in microcanonical molecular dynamics simulations. Our main finding is that the entropy is a concave function of the energy for all values of the magnetization, but is nonconcave as a function of the magnetization for some values of the energy. This last property implies that the magnetic susceptibility of the model can be negative when calculated microcanonically for fixed values of the energy and magnetization. This provides a magnetization analog of negative heat capacities, which are well-known to be associated in general with the nonequivalence of the microcanonical and canonical ensembles. Here, the two ensembles that are nonequivalent are the microcanonical ensemble in which the energy and magnetization are held fixed and the canonical ensemble in which the energy and magnetization are fixed only on average by fixing the temperature and magnetic field.Comment: 14 pages, 4 figures, 2 appendices, REVTeX

Drinking-Water Herbicide Exposure in Indiana and Prevalence of Small-for-Gestational-Age and Preterm Delivery

Bac k g r o u n d: Atrazine and other corn herbicides are routinely detected in drinking water. Two studies on potential association of atrazine with small-for-gestational-age (SGA) and preterm birth prevalence found inconsistent results. Moreover, these studies did not control for individual-level potential confounders. Objectives: Our retrospective cohort study evaluated whether atrazine in drinking water is associated with increased prevalence of SGA and preterm birth. Me t h o d s: We developed atrazine concentration time series for 19 water systems in Indiana from 1993 to 2007 and selected all births (n = 24,154) based on geocoded mother’s residences. Logbinomial models were used to estimate prevalence ratios (PRs) for SGA and preterm delivery in relation to atrazine concentrations during various periods of the pregnancy. Models controlled for maternal demographic characteristics, prenatal care and reproductive history, and behavioral risk factors (smoking, drinking, drug use). Re s u l t s: Atrazine in drinking water during the third trimester and the entire pregnancy was associated with a significant increase in the prevalence of SGA. Atrazine in drinking water> 0.1 µg/L during the third trimester resulted in a 17–19 % increase in the prevalence of SGA compared with the control group (< 0.1 µg/L). Mean atrazine concentrations over the entire pregnancy> 0.644 µg/L were associated with higher SGA prevalence than in the control group (adjusted PR = 1.14; 95% confidence interval, 1.03–1.24). No significant association was found for preterm delivery. Con c l u s i o n s: We found that atrazine, and perhaps other co-occurring herbicides in drinking water, is associated with an increased prevalence of SGA, but not preterm delivery. Key w o r d s: atrazine, birth weight, epidemiology, herbicides, preterm birth. Environ Health Perspect 117:1619–1624 (2009). doi:10.1289/ehp.0900784 available vi