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Precise instrumental calibration is of crucial importance to 21-cm cosmology experiments. The Murchison Widefield Array’s (MWA) Phase II compact configuration offers us opportunities for both redundant calibration and sky-based calibration algorithms; using the two in tandem is a potential approach to mitigate calibration errors caused by inaccurate sky models. The MWA Epoch of Reionization (EoR) experiment targets three patches of the sky (dubbed EoR0, EoR1, and EoR2) with deep observations. Previous work in Li et al. (2018) and (2019) studied the effect of tandem calibration on the EoR0 field and found that it yielded no significant improvement in the power spectrum (PS) over sky-based calibration alone. In this work, we apply similar techniques to the EoR1 field and find a distinct result: the improvements in the PS from tandem calibration are significant. To understand this result, we analyse both the calibration solutions themselves and the effects on the PS over three nights of EoR1 observations. We conclude that the presence of the bright radio galaxy Fornax A in EoR1 degrades the performance of sky-based calibration, which in turn enables redundant calibration to have a larger impact. These results suggest that redundant calibration can indeed mitigate some level of model incompleteness error.
Psychosocial stress in childhood and adolescence is linked to stress system dysregulation, although few studies have examined the relative impacts of parental harshness and parental disengagement. This study prospectively tested whether parental harshness and disengagement show differential associations with overall cortisol output in adolescence. Associations between overall cortisol output and adolescent mental health problems were tested concurrently. Adolescents from the Fragile Families and Child Wellbeing Study (FFCWS) provided hair samples for cortisol assay at 15 years (N = 171). Caregivers reported on parental harshness and disengagement experiences at 1, 3, 5, 9, and 15 years, and adolescents reported at 15 years. Both parent and adolescent reported depressive and anxiety symptoms and antisocial behaviors at 15. Greater parental harshness from 1–15 years, and harshness reported at 15 years in particular, was associated with higher overall cortisol output at 15. Greater parental disengagement from 1–15 years, and disengagement at 1 year specifically, was associated with lower cortisol output. There were no significant associations between cortisol output and depressive symptoms, anxiety symptoms, or antisocial behaviors. These results suggest that the unique variances of parental harshness and disengagement may have opposing associations with cortisol output at 15 years, with unclear implications for adolescent mental health.
We apply two methods to estimate the 21-cm bispectrum from data taken within the Epoch of Reionisation (EoR) project of the Murchison Widefield Array (MWA). Using data acquired with the Phase II compact array allows a direct bispectrum estimate to be undertaken on the multiple redundantly spaced triangles of antenna tiles, as well as an estimate based on data gridded to the uv-plane. The direct and gridded bispectrum estimators are applied to 21 h of high-band (167–197 MHz; z = 6.2–7.5) data from the 2016 and 2017 observing seasons. Analytic predictions for the bispectrum bias and variance for point-source foregrounds are derived. We compare the output of these approaches, the foreground contribution to the signal, and future prospects for measuring the bispectra with redundant and non-redundant arrays. We find that some triangle configurations yield bispectrum estimates that are consistent with the expected noise level after 10 h, while equilateral configurations are strongly foreground-dominated. Careful choice of triangle configurations may be made to reduce foreground bias that hinders power spectrum estimators, and the 21-cm bispectrum may be accessible in less time than the 21-cm power spectrum for some wave modes, with detections in hundreds of hours.
The Southern African Radiocarbon Database (SARD) is a new online, open-access database of published radiocarbon dates from southern African archaeological contexts. Compatible with the calibration, Bayesian modelling and mapping functionality of the OxCal software, the SARD will greatly assist in the documentation and analysis of chronological trends across the subcontinent. This article introduces the database and presents two case studies that demonstrate its utility and its integration with OxCal, comparing the temporal distribution of radiocarbon dates in two archaeologically well-investigated regions, and assessing the timing of Middle to Later Stone Age technological developments across the African subcontinent.
Ocular complaints prompt a significant number of emergency department (ED) visits, and they can range from benign to sight-threatening. Detailed fundoscopic examination is difficult, even for experienced providers. Point-of-care ultrasound (POCUS) is increasingly utilized in the ED for numerous applications, including ocular evaluation. We present a case in which ocular POCUS was used to diagnose a submacular hemorrhage in a patient who presented with acute painless loss of vision. Ocular POCUS can be readily employed to assess for myriad clinically significant pathologies.
The early village at Çatalhöyük (7100–6150 BC) provides important evidence for the Neolithic and Chalcolithic people of central Anatolia. This article reports on the use of lipid biomarker analysis to identify human coprolites from midden deposits, and microscopy to analyse these coprolites and soil samples from human burials. Whipworm (Trichuris trichiura) eggs are identified in two coprolites, but the pelvic soil samples are negative for parasites. Çatalhöyük is one of the earliest Eurasian sites to undergo palaeoparasitological analysis to date. The results inform how intestinal parasitic infection changed as humans modified their subsistence strategies from hunting and gathering to settled farming.
Women have organized around their gendered identity to accomplish political goals both inside and outside legislatures. Formal and informal institutional norms shape the form this collective action takes and whether it is successful. What, then, are the favorable conditions for organizing women's caucuses inside legislatures? Using an original dataset and employing an event history analysis, we identify the institutional conditions under which women's caucuses emerged in the 50 US states from 1972 to 2009. Within a feminist institutional framework, we argue that women's ability to alter existing organizational structures and potentially affect gender norms within legislatures is contextual. Although we find that women's presence in conjunction with Democratic Party control partially explains women's ability to act collectively and in a bipartisan way within legislatures, our analysis suggests that institutional-level variables are not enough to untangle this complicated phenomenon. Our work explains how gender and party interact to shape legislative behavior and clarifies the intractability of institutional norms while compelling further qualitative evidence to uncover the best conditions for women's collective action within legislatures.
The depressive-realism effect refers to a phenomenon in which depressed individuals are more realistic at assessing the relationship between two events than non-depressed individuals. Recent evidence suggests that the depressive realism hypothesis is weaker than first thought. Thus, we sought evidence for depressive-realism under conditions that we hypothesised would maximise the effect. We tested a clinically depressed sample of participants who were administered a rumination induction. Twenty-eight clinically depressed and 39 non-depressed participants were randomly allocated to either a rumination condition (focused on the causes, consequences, and meaning of their mood) or a distraction condition (focused on external objects/events such as a classroom). Participants then completed a contingency task in which there was no relationship between their responses and an outcome, and they were asked to make a judgment of how much control they had over an outcome. Both groups and conditions did not differ in their judgments of control; participants in all conditions showed a non-normative judgment of control. The depressive-realism effect was not observed in this study, even when depressed participants were encouraged to ruminate. Rather, the present study clearly demonstrates the robustness of the illusion of control.