We review evidence of racial discrimination as a critical and understudied form of adversity that has the potential to impact stress biology, particularly hypothalamic–pituitary–adrenal (HPA) axis activity. We highlight ethnic racial identity (ERI) as a positive regulatory influence on HPA axis activity, as indexed by levels of salivary cortisol. In past research by our group, Black individuals with high adolescent discrimination had low adult cortisol levels (hypocortisolism). Here, we present new analyses showing that ERI, measured prospectively from ages 12 through 32 in 112 Black and white individuals, is related to better-regulated cortisol levels in adulthood, particularly for Black participants. We also describe ongoing research that explores whether the promotion of ERI during adolescence can reduce ethnic–racial disparities in stress biology and in emotional health and academic outcomes.

Parents serve important functions in regulating children's responses to stress and challenge. However, the parental characteristics that modulate the effectiveness of parents as stress buffers remain to be fully characterized. To address this gap, this study examined parental characteristics and behaviors that may explain variation in parents’ ability to buffer cortisol responses to acute stress of 180 children (ages 9–11 years old, M = 9.9 years, SD = .58). Children were randomly assigned to either participate in a public speaking task, the Trier Social Stress Test – modified for children (TSST-M) or a control condition. Children in the TSST-M condition were randomly assigned to prepare for the public speaking task either with their parent (N = 59) or alone (N = 60), whereas 61 children were assigned to the control condition (no TSST-M). We found that parental education moderated the effect of condition on children's responses to acute stress. Children whose parents had lower levels of education exhibited reduced cortisol responses in the parent condition compared to the alone condition, showing a buffered pattern of reactivity. In contrast, children of parents with high levels of education displayed higher cortisol reactivity in the parent condition compared to the alone and control conditions. Parental education was also positively associated with higher levels of state anxiety within the parent condition. These results suggest that highly educated parents may emphasize performance over comfort, amplifying their children's state anxiety and cortisol responses to a public performance.

The Rapid ASKAP Continuum Survey (RACS) is the first large-area survey to be conducted with the full 36-antenna Australian Square Kilometre Array Pathfinder (ASKAP) telescope. RACS will provide a shallow model of the ASKAP sky that will aid the calibration of future deep ASKAP surveys. RACS will cover the whole sky visible from the ASKAP site in Western Australia and will cover the full ASKAP band of 700–1800 MHz. The RACS images are generally deeper than the existing NRAO VLA Sky Survey and Sydney University Molonglo Sky Survey radio surveys and have better spatial resolution. All RACS survey products will be public, including radio images (with $\sim$ 15 arcsec resolution) and catalogues of about three million source components with spectral index and polarisation information. In this paper, we present a description of the RACS survey and the first data release of 903 images covering the sky south of declination $+41^\circ$ made over a 288-MHz band centred at 887.5 MHz.

Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter phenology in thirteen economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after physiological maturity at multiple sites spread across fourteen states in the southern, northern, and mid-Atlantic U.S. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate increased at northern latitudes. Amaranthus species seed shatter was low (0 to 2%), whereas shatter varied widely in common ragweed (Ambrosia artemisiifolia L.) (2 to 90%) over the weeks following soybean physiological maturity. Overall, the broadleaf species studied shattered less than ten percent of their seeds by soybean harvest. Our results suggest that some of the broadleaf species with greater seed retention rates in the weeks following soybean physiological maturity may be good candidates for HWSC.

Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.

Antibiotics are not indicated for the treatment of bronchitis and bronchiolitis. Using a nationally representative database from 2006–2015, we found that antibiotics were prescribed in 58% of outpatient visits for bronchitis and bronchiolitis in children, serving as a possible baseline for the expanded HEDIS 2020 measure regarding antibiotic prescribing for bronchitis.

POST goosegrass and other grassy weed control in bermudagrass is problematic. Fewer herbicides that can control goosegrass are available due to regulatory pressure and herbicide resistance. Alternative herbicide options that offer effective control are needed. Previous research demonstrates that topramezone controls goosegrass, crabgrass, and other weed species; however, injury to bermudagrass may be unacceptable. The objective of this research was to evaluate the safening potential of topramezone combinations with different additives on bermudagrass. Field trials were conducted at Auburn University during summer and fall from 2015 to 2018 and 2017 to 2018, respectively. Treatments included topramezone mixtures and methylated seed oil applied in combination with five different additives: triclopyr, green turf pigment, green turf paint, ammonium sulfate, and chelated iron. Bermudagrass bleaching and necrosis symptoms were visually rated. Normalized-difference vegetative index measurements and clipping yield data were also collected. Topramezone plus chelated iron, as well as topramezone plus triclopyr, reduced bleaching potential the best; however, the combination of topramezone plus triclopyr resulted in necrosis that outweighed reductions in bleaching. Masking agents such as green turf paint and green turf pigment were ineffective in reducing injury when applied with topramezone. The combination of topramezone plus ammonium sulfate should be avoided because of the high level of necrosis. Topramezone-associated bleaching symptoms were transient and lasted 7 to 14 d on average. Findings from this research suggest that chelated iron added to topramezone and methylated seed oil mixtures acted as a safener on bermudagrass.

This article explores the causes of authoritarian durability. Why do some authoritarian regimes survive for decades, often despite severe crises, while others collapse quickly, even absent significant challenges? Based on an analysis of all authoritarian regimes between 1900 and 2015, the authors argue that regimes founded in violent social revolution are especially durable. Revolutionary regimes, such as those in Russia, China, Cuba, and Vietnam, endured for more than half a century in the face of strong external pressure, poor economic performance, and large-scale policy failures. The authors develop and test a theory that accounts for such durability using a novel data set of revolutionary regimes since 1900. The authors contend that autocracies that emerge out of violent social revolution tend to confront extraordinary military threats, which lead to the development of cohesive ruling parties and powerful and loyal security apparatuses, as well as to the destruction of alternative power centers. These characteristics account for revolutionary regimes’ unusual longevity.

Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.

We describe system verification tests and early science results from the pulsar processor (PTUSE) developed for the newly commissioned 64-dish SARAO MeerKAT radio telescope in South Africa. MeerKAT is a high-gain ( ${\sim}2.8\,\mbox{K Jy}^{-1}$ ) low-system temperature ( ${\sim}18\,\mbox{K at }20\,\mbox{cm}$ ) radio array that currently operates at 580–1 670 MHz and can produce tied-array beams suitable for pulsar observations. This paper presents results from the MeerTime Large Survey Project and commissioning tests with PTUSE. Highlights include observations of the double pulsar $\mbox{J}0737{-}3039\mbox{A}$ , pulse profiles from 34 millisecond pulsars (MSPs) from a single 2.5-h observation of the Globular cluster Terzan 5, the rotation measure of Ter5O, a 420-sigma giant pulse from the Large Magellanic Cloud pulsar PSR $\mbox{J}0540{-}6919$ , and nulling identified in the slow pulsar PSR J0633–2015. One of the key design specifications for MeerKAT was absolute timing errors of less than 5 ns using their novel precise time system. Our timing of two bright MSPs confirm that MeerKAT delivers exceptional timing. PSR $\mbox{J}2241{-}5236$ exhibits a jitter limit of $<4\,\mbox{ns h}^{-1}$ whilst timing of PSR $\mbox{J}1909{-}3744$ over almost 11 months yields an rms residual of 66 ns with only 4 min integrations. Our results confirm that the MeerKAT is an exceptional pulsar telescope. The array can be split into four separate sub-arrays to time over 1 000 pulsars per day and the future deployment of S-band (1 750–3 500 MHz) receivers will further enhance its capabilities.

Conventional wisdom holds that great power patrons prop up client dictatorships. But this is generally assumed rather than systematically analyzed. This article provides the first comprehensive analysis of the relationship between foreign sponsorship and authoritarian regime survival, using an original data set of all autocratic client regimes in the postwar period. The results demonstrate that patronage from Western powers—the United States, France, and the United Kingdom—is not associated with client regime survival. Rather, it’s only Soviet sponsorship that reduced the risk of regime collapse. The author explains this variation by considering the effects of foreign sponsorship on the likelihood of military coups d’état. He argues that the Soviet Union directly aided its clients by imposing a series of highly effective coup prevention strategies. By contrast, the US and its allies didn’t provide such aid, leaving regimes vulnerable to military overthrow.

The development of a therapeutic alliance with the patient is a challenge for emergency psychiatry. The therapeutic alliance could reduce the number of non-voluntary admissions and of compulsory administration of medication. Moreover, a better dialogue with the patients could increase the patients’ compliance with ambulatory care, and could prevent inutile hospitalizations. To evaluate the level of satisfaction with the emergency psychiatric treatment we created and validated a 10-item questionnaire. The questionnaire focuses on the “human quality” and the empathy of the psychiatrist, but also on his professional skills, the delay in the waiting room before medical evaluation, the level of satisfaction concerning the proposed care and a comparison between psychiatrists, nurses and the security staff. The same questionnaire is proposed to the patients and to the psychiatrists. The validation is still running and focuses on around 5000 patients admitted in emergency during one year (June 2007-June 2008). Preliminary results are discussed, taking into account diagnosis and differences between patients and psychiatrists about their therapeutic alliance.