Characterizing the structure and composition of clay minerals on the surface of Mars is important for reconstructing past aqueous processes and environments. Data from the CheMin X-ray diffraction (XRD) instrument on the Mars Science Laboratory Curiosity rover demonstrate a ubiquitous presence of collapsed smectite (basal spacing of 10 Å) in ~3.6-billion-year-old lacustrine mudstone in Gale crater, except for expanded smectite (basal spacing of 13.5 Å) at the base of the stratigraphic section in a location called Yellowknife Bay. Hypotheses to explain expanded smectite include partial chloritization by Mg(OH)2 or solvation-shell H2O molecules associated with interlayer Mg2+. The objective of this work is to test these hypotheses by measuring partially chloritized and Mg-saturated smectite using laboratory instruments that are analogous to those on Mars rovers and orbiters. This work presents Mars-analog XRD, evolved gas analysis (EGA), and visible/shortwave-infrared (VSWIR) data from three smectite standards that were Mg-saturated and partially and fully chloritized with Mg(OH)2. Laboratory data are compared with XRD and EGA data collected from Yellowknife Bay by the Curiosity rover to examine whether the expanded smectite can be explained by partial chloritization and what this implies about the diagenetic history of Gale crater. Spectral signatures of partial chloritization by hydroxy-Mg are investigated that may allow the identification of partially chloritized smectite in Martian VSWIR reflectance spectra collected from orbit or in situ by the SuperCam instrument suite on the Mars 2020 Perseverance rover. Laboratory XRD and EGA data of partially chloritized saponite are consistent with data collected from Curiosity. The presence of partially chloritized (with Mg(OH)2) saponite in Gale crater suggests brief interactions between diagenetic alkaline Mg2+-bearing fluids and some of the mudstone exposed at Yellowknife Bay, but not in other parts of the stratigraphic section. The location of Yellowknife Bay at the base of the stratigraphic section may explain the presence of alkaline Mg2+-bearing fluids here but not in other areas of Gale crater investigated by Curiosity. Early diagenetic fluids may have had a sufficiently long residence time in a closed system to equilibrate with basaltic minerals, creating an elevated pH, whereas diagenetic environments higher in the section may have been in an open system, therefore preventing fluid pH from becoming alkaline.

Through a series of example research studies, we illustrate processes in translating case report forms to increase language diversity in study populations while simultaneously highlighting implications for data collection and analyses. The Northwestern University Data Analysis and Coordinating Center manages the translation of participant-facing study documents into languages other than English through a process that has been refined over several years, adjusting for changes in technical capabilities in electronic case report forms. This approach to manage, examine for context, and implement certified case report form translations offers an efficient workflow to streamline data capture in multiple languages.

This repeated cross-sectional study assessed the validity and reproducibility of the myfood24® dietary assessment tool against dietary intake biomarkers in healthy Danish adults. The study included 71 healthy adults (14/57 m/f), aged 53.2 ± 9.1 years with an average BMI of 26.1 ± 0.3 kg/m2. Participants were instructed to complete seven-day weighed food records using myfood24® at baseline and 4 ± 1 weeks thereafter. Estimated mean dietary intake was compared with objective measures of energy metabolism and selected dietary intake biomarkers in fasting blood (folate) and in 24-hour urine (urea, potassium). Resting energy expenditure was measured by indirect calorimetry. Application of the Goldberg cut-off classified 87% (n = 62) of participants as acceptable reporters. A strong Spearman’s rank correlation was observed between total folate intake and serum folate (ρ = 0.62). Acceptable correlations were noted for serum folate (ρ = 0.49) and urinary potassium excretion (ρ = 0.44) with estimated and measured protein intake (ρ = 0.45); energy intake and total energy expenditure (ρ = 0.38); potassium intake and potassium excretion (ρ = 0.42); and estimated fruit and vegetable intake. Reproducibility analysis revealed strong correlations (ρ ≥ 0.50) across most nutrients and food groups, except for fish and vitamin D (ρ = 0.30 and ρ = 0.26, respectively). Notably, reproducibility for folate and total vegetable intake exhibited the highest correlations (ρ = 0.84 and ρ = 0.78, respectively). In conclusion, while some limitations exist, myfood24® remains a useful tool for ranking individuals by intake, particularly in studies focusing on relative comparisons.

Contaminated surfaces in clinics pose a pathogen transmission risk. Far ultraviolet-C light (UVC), with a favorable safety profile for human exposure, has the potential for continuous pathogen inactivation in occupied clinical areas. This study demonstrated real-world bioburden reduction on surfaces, despite frequent contamination from routine use by staff and patients in clinics.

All regimes require supporters to govern and survive. We discuss the concept of a ‘regime support group’ and present and validate measures from an extensive dataset recording different features of such groups. This Regime Support and Opposition Groups (ReSOG) dataset covers approximately 2,000 political regimes from almost 200 countries, across 1789–2020. Drawing on the knowledge of about 1,000 country experts, we estimate the size and main geographical location of regime support coalitions and key opposition actors. We also map the social basis of regime support coalitions and opponents, using a 14-category scheme covering various social groups. These data provide a unique quantitative history of the social underpinnings of regimes in the modern era. Using them, we show and discuss the broadening of support coalitions over time, especially in autocracies, the rise of major urban groups, and the relative decline of rural elites in politics, globally.

This article explores Francesco Guicciardini’s concept of the imagination and argues that it plays a vital, yet hitherto unexplored, role in his political thought. What are called “imaginary conceptions” determine the effects that different governmental strategies have upon a given society. As these both affective and cognitive conceptions are tied to shared, symbolic representations, understanding informal aspects of political life becomes a crucial aspect of Guicciardini’s construal of effective government. To understand these aspects it is necessary to reconstruct the historical genesis of the communal representations as it determines the specificity of the society under consideration. The historical contingency of a society’s imaginary conceptions forces political theory to “imaginatively construct” the institutional forms it suggests, rather than “discover” them among the exempla of the past. The centrality of contingent, imaginary conceptions to political reality leads Guicciardini to break with former Renaissance conceptions of exemplarity.

Politicians frequently face toxic behaviors. We argue that these behaviors impose a double burden on women, who may not only face higher exposure to toxicity, but experience attacks that they and others understand to be motivated by prejudice and designed to push them out of office. Using large-scale image-based conjoint experiments in the United States, Denmark, Belgium, and Chile, we demonstrate that both politicians themselves and citizens regard messages targeting women politicians as more toxic than otherwise equivalent messages targeting men. This perception intensifies when messages mention gender or come from perpetrators who are men. A second experiment to investigate the mechanisms shows that hostile behaviors toward women are more frequently understood as driven by prejudice and attempts to remove women from politics. These findings highlight the importance of understanding how perceptions of perpetrators’ motives affect the severity of political toxicity, and provide insights into the gendered effects of political hostility.

We study a skew product transformation associated to an irrational rotation of the circle $[0,1]/\sim $. This skew product keeps track of the number of times an orbit of the rotation lands in the two complementary intervals of $\{0,1/2\}$ in the circle. We show that under certain conditions on the continued fraction expansion of the irrational number defining the rotation, the skew product transformation has certain dense orbits. This is in spite of the presence of numerous non-dense orbits. We use this to construct laminations on infinite type surfaces with exotic properties. In particular, we show that for every infinite type surface with an isolated planar end, there is an infinite clique of $2$-filling rays based at that end. These $2$-filling rays are relevant to Bavard and Walker’s loop graphs.

While political scientists regularly engage in spirited theoretical debates about elections and voting behavior, few have noticed that elected politicians also have theories of elections and voting. Here, we investigate politicians’ positions on eight central theoretical debates in the area of elections and voting behavior and compare politicians’ theories to those held by ordinary citizens. Using data from face-to-face interviews with nearly one thousand politicians in 11 countries, together with corresponding surveys of more than twelve thousand citizens, we show that politicians overwhelmingly hold thin, minimalist, “democratic realist” theories of voting, while citizens’ theories are more optimistic and policy oriented. Politicians’ theoretical tendencies—along with their theoretical misalignment from citizens—are remarkably consistent across countries. These theories are likely to have important consequences for how politicians campaign, communicate with the public, think about public policy, and represent their constituents.

Cover crops are important in organic arable cropping systems because they improve soil fertility and suppress annual weeds in the post-harvest period (the period between cash crops), but their effectiveness against perennial weeds is less clear. This study analyzed outbreaks of perennial weeds in two long-term organic crop rotations with and without cover crops in the period 2011–2022 in Denmark. In addition, the impact of including forage plantain (Plantago lanceolata) in cover crop mixtures on the growth of perennial weeds was studied from 2020 to 2022. P. lanceolata is known to contain secondary metabolites that inhibit nitrification and may influence nitrogen (N) availability. This study found that cover crops did not hinder outbreaks of Cirsium arvense, Sonchus arvensis, Elytrigia repens or other perennial weed species. E. repens actually proliferated more with cover crops whose presence prevented repeated mechanical post-harvest interventions. The crop rotation involving regular cutting of a one-year or two-year green manure crop provided the best management of perennial weeds if repeated post-harvest soil cultivation was also conducted. This could only be done in the absence of cover crops. Mixing P. lanceolata into the cover crop mixtures did not change the outcome of competition between cover crops and perennial weeds in the period between crop harvest in August and November. Instead, P. lanceolata significantly reduced the number of shoots emerging from perennial weeds in the subsequent growing season. The causality of this effect was not further elaborated in the study.

Given an algebra and a finite group acting on it via automorphisms, a natural object of study is the associated skew group algebra. In this article, we study the relationship between quasi-hereditary structures on the original algebra and on the corresponding skew group algebra. Assuming a natural compatibility condition on the partial order, we show that the skew group algebra is quasi-hereditary if and only if the original algebra is. Moreover, we show that in this setting an exact Borel subalgebra of the original algebra which is invariant as a set under the group action gives rise to an exact Borel subalgebra of the skew group algebra and that under this construction, properties such as normality and regularity of the exact Borel subalgebra are preserved.