The incorporation of bentonites in aflatoxin-contaminated animal feeds to remedy aflatoxicosis has been tested widely in animal trials. Yet, a large variation in efficacy among samples has been observed which has been attributed to variations in the properties of the clay mineral adsorbents. The objectives of the current study were: (1) to evaluate the mineral and chemical composition of two selected bentonites to find minerals or elements which are potentially of concern; (2) to characterize the aflatoxin B1 (AfB1) adsorption (selectivity, capacity, reversibility, and interlayer accessibility) by the bentonites; and (3) to evaluate the safety and efficacy of selected clays as amendments of aflatoxin-contaminated feed for broiler chickens. The mineral, chemical, and exchange cation composition of the clays were analyzed, and they appeared to be safe for use in feed. The bentonites and their fractions showed that adsorption capacities range from 0.48 to 0.97 mol/kg. The interlayer spaces of both montmorillonites were accessible by AfB1, and the adsorption was irreversible. Three-day old broiler chickens were given clean and high-aflatoxin-concentration (1400 mg/kg) diets with and without the presence of the two bentonites. After three weeks the chickens were sacrificed and biomarkers were evaluated. The presence of aflatoxins reduced the body weight by 58% and resulted in a 25% mortality rate. Adding bentonites 1TX and 4TX increased the body weight of the chickens by 14 and 23%, respectively, but did not improve the mortality rates. The results suggested that selected bentonites could effectively sequester aflatoxins in vivo but did not eliminate the total toxicity present in highly contaminated poultry feed.

Moderates are often overlooked in contemporary research on American voters. Many scholars who have examined moderates argue that these individuals are only classified as such due to a lack of political sophistication or conflicted views across issues. We develop a method to distinguish three ways an individual might be classified as moderate: having genuinely moderate views across issues, being inattentive to politics or political surveys, or holding views poorly summarized by a single liberal–conservative dimension. We find that a single ideological dimension accurately describes most, but not all, Americans’ policy views. Using the classifications from our model, we demonstrate that moderates and those whose views are not well explained by a single dimension are especially consequential for electoral selection and accountability. These results suggest a need for renewed attention to the middle of the American political spectrum.

We study the number of random permutations needed to invariably generate the symmetric group Sn when the distribution of cycle counts has the strong α-logarithmic property. The canonical example is the Ewens sampling formula, for which the special case α = 1 corresponds to uniformly random permutations.

For strong α-logarithmic measures and almost every α, we show that precisely ⌈(1−αlog2)−1⌉ permutations are needed to invariably generate Sn with asymptotically positive probability. A corollary is that for many other probability measures on Sn no fixed number of permutations will invariably generate Sn with positive probability. Along the way we generalize classic theorems of Erdős, Tehran, Pyber, Łuczak and Bovey to permutations obtained from the Ewens sampling formula.

Between 2003 and 2007, North Gasherbrum Glacier on the northeastern slope of the Karakoram mountains in Asia underwent a dramatic acceleration, during which a velocity wave propagated down the glacier. There was a significant transfer of ice from up-glacier downstream, which resulted in a strong surface elevation increase over the lower tongue, but only a moderate advance of the glacier snout. We interpret this behaviour as that of a glacier surge, and we explain the observations by means of a simple version of the Kamb drainage-switching theory.

In this paper we undertake a quantitative analysis of the dynamic process by which ice underneath a dry porous debris layer melts. We show that the incorporation of debris-layer airflow into a theoretical model of glacial melting can capture the empirically observed features of the so-called Østrem curve (a plot of the melt rate as a function of debris depth). Specifically, we show that the turning point in the Østrem curve can be caused by two distinct mechanisms: the increase in the proportion of ice that is debris-covered and/or a reduction in the evaporative heat flux as the debris layer thickens. This second effect causes an increased melt rate because the reduction in (latent) energy used for evaporation increases the amount of energy available for melting. Our model provides an explicit prediction for the melt rate and the temperature distribution within the debris layer, and provides insight into the relative importance of the two effects responsible for the maximum in the Østrem curve. We use the data of Nicholson and Benn (2006) to show that our model is consistent with existing empirical measurements.

Recession of the Laurentide Ice Sheet from northern New Hampshire was interrupted by the Littleton-Bethlehem (L-B) readvance and deposition of the extensive White Mountain Moraine System (WMMS). Our mapping of this moraine belt and related glacial lake sequence has refined the deglaciation history of the region. The age of the western part of the WMMS is constrained to ~14.0–13.8 cal ka BP by glacial Lake Hitchcock varves that occur beneath and above L-B readvance till and were matched to a revised calibration of the North American Varve Chronology presented here. Using this age for when boulders were deposited on the moraines has enabled calibration of regional cosmogenic-nuclide production rates to improve the precision of exposure dating in New England. The L-B readvance coincided with the Older Dryas (OD) cooling documented by workers in Europe and the equivalent GI-1d cooling event in the Greenland Ice Core Chronology 2005 (GICC05) time scale. The readvance and associated moraines provide the first well-documented and dated evidence of the OD event in the northeastern United States. Our lake sediment cores show that the Younger Dryas cooling was likewise prominent in the White Mountains, thus extending the record of this event westward from Maine and Maritime Canada.

How does living in a battleground state during a presidential election affect an individual’s political engagement? We utilize a unique collection of 113 million Facebook status updates to compare users’ political discussion during the 2008 election. “Battleground” state users are significantly more likely to discuss politics in the campaign season than are users in uncompetitive “blackout” states. Posting a political status update—a form of day-to-day engagement with politics—mediates ∼20 percent of the relationship between exposure to political competition and self-reported voter turnout. This paper is among the first to use a massive quantity of social media data to explain the microfoundations of how people think, feel, and act on a daily basis in response to their political environment.

The American Political Science Review recently published a critique of an article we published in the Journal of Politics in 2008. In that article we showed that variants of the genes 5HTT and MAOA were significantly associated with voter turnout in a sample of 2,300 subjects from the National Longitudinal Study of Adolescent Health. Here, we address the critique first by conducting a replication study using an independent sample of 9,300 subjects. This study replicates the gene-environment interaction of the 5HTT gene variant with church attendance, but not the association with MAOA. We then focus on the general argument of the critique, showing that many of its characterizations of the literature in genetics and in political science are misleading or incorrect. We conclude by illustrating the ways in which genopolitics has already made a lasting contribution to the field of political science and by offering guidelines for future studies in genopolitics that are based on state-of-the-art recommendations from the field of behavior genetics.

Models of political participation have begun to incorporate actors who possess “social preferences.” However, these models have failed to take into account the potentially incongruent political goals of different social preference types. These goals are likely to play an important role in shaping political behavior. To examine the effect of distinct social preferences on political activity we conducted an experiment in which participants played five rounds of a modified dictator game (Andreoni and Miller2002). We used the decisions in these games to determine their preference type and mapped these types to reported political activity. Our results show that subjects who were most interested in increasing total welfare in the dictator game were more likely to participate in politics than subjects with selfish preferences, whereas subjects most interested in reducing the difference between their own well-being and the well-being of others were no more likely to participate than subjects with selfish preferences.

The decision to vote has puzzled scholars for decades. Theoretical models predict little or no variation in participation in large population elections and empirical models have typically accounted for only a relatively small portion of individual-level variance in turnout behavior. However, these models have not considered the hypothesis that part of the variation in voting behavior can be attributed to genetic effects. Matching public voter turnout records in Los Angeles to a twin registry, we study the heritability of political behavior in monozygotic and dizygotic twins. The results show that a significant proportion of the variation in voting turnout can be accounted for by genes. We also replicate these results with data from the National Longitudinal Study of Adolescent Health and show that they extend to a broad class of acts of political participation. These are the first findings to suggest that humans exhibit genetic variation in their tendency to participate in political activities.

Phil C. Weigand has devoted his career to the anthropology and archaeology of the most poorly known area of Mesoamerica, “an enormous area of elaborate cultural development [that] has been relegated to unimportance” (Weigand and Foster 1985:5). We refer, of course, to the Occidente or West Mexico, roughly defined by the states of Michoacán, Colima, Jalisco, and Nayarit, often including parts of Guanajuato, Zacatecas, Sinaloa, and sometimes Guerrero. Over the course of his career, Weigand has integrated data from archaeology, ethnohistory, and ethnography to gain a better understanding of western Mesoamerica. This Special Section is an homenaje to Phil that draws together contributions by some of his friends and colleagues who have felt his influence over the years.

Mammogenesis and lactation were induced in five multiparous, non-pregnant goats by treatment with oestrogen and progesterone for 11 d, followed by dexamethasone for 3 d. Reserpine was administered during the last 5 d. All five goats lactated, although milk yield was less than had been achieved in previous natural lactations. Mammary development was assessed in vivo, using magnetic resonance imaging. Although parenchyma volume increased by more than 6-fold overall, only 25% of this increase occurred during steroid treatment. Most development took place after the cessation of treatment, when milking commenced. Maximum size was not achieved until week 8 of the induced lactation, and was only 70% of normal parenchyma volume. After 18 weeks lactation the activities of three key milk synthetic enzymes were very similar to values previously found in natural lactations, and secretion efficiency (milk production per unit volume of parenchyma) was also similar to that of natural lactations. We conclude that the lower than normal milk yields were associated with incomplete proliferation of mammary tissue, rather than inadequate differentiation of individual secretory cells.

Four goats were studied from the end of their second lactation. One mammary gland of each goat was dried off just prior to the start of the third gestation, whilst the other gland was milked throughout gestation, with no dry period. At the end of gestation the continuously milked gland was significantly smaller than the gland that had been allowed a dry period. However, this difference did not persist beyond parturition and there was no significant difference between the milk yields of the two glands in the next lactation, although the continuously milked gland tended to have the higher yield. At 18 weeks of lactation, mammary parenchyma weight and secretory cell number were significantly greater in the continuously milked gland, but mammary enzyme activities did not differ between the two glands.