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Cities have suffered from three years of the COVID-19 pandemic and are increasingly experiencing exacerbated heatwaves, floods, and droughts due to climate change. Going forward, cities need to address both climate and public health crises effectively while reducing poverty and inequity, often in the context of economic pressure and declining levels of trust in government. The COVID-19 pandemic has revealed gaps in city readiness for simultaneous responses to pandemics and climate change, particularly in the Global South. However, these concurrent challenges to cities present an opportunity to reformulate current urbanization patterns and the economies and dynamics they enable. This Element focuses on understanding COVID-19's impact on city systems related to climate change mitigation and adaptation, and vice versa, in terms of warnings, lessons learned, and calls to action. This title is also available as open access on Cambridge Core.
The role of adsorbed and structural Fe3+ in palygorskite and sepiolite with respect to the oxidation of hydrocortisone in aqueous suspension has been evaluated using electron spin resonance and UV-visible spectroscopy. Natural surface-adsorbed Fe3+ showed an important activity in the oxidation process, although smaller than octahedral Fe3+. The kinetics of oxidative degradation of hydrocortisone by palygorskite appear to be composed of two apparent first order reactions which may be associated with two kinds of sites for Fe in palygorskite. The lower oxidizing power of sepiolite for hydrocortisone degradation is due to its very low Fe3+ content.
We report the discovery of a bow-shock pulsar wind nebula (PWN), named Potoroo, and the detection of a young pulsar J1638$-$4713 that powers the nebula. We present a radio continuum study of the PWN based on 20-cm observations obtained from the Australian Square Kilometre Array Pathfinder (ASKAP) and MeerKAT. PSR J1638$-$4713 was identified using Parkes radio telescope observations at frequencies above 3 GHz. The pulsar has the second-highest dispersion measure of all known radio pulsars (1 553 pc cm$^{-3}$), a spin period of 65.74 ms and a spin-down luminosity of $\dot{E}=6.1\times10^{36}$ erg s$^{-1}$. The PWN has a cometary morphology and one of the greatest projected lengths among all the observed pulsar radio tails, measuring over 21 pc for an assumed distance of 10 kpc. The remarkably long tail and atypically steep radio spectral index are attributed to the interplay of a supernova reverse shock and the PWN. The originating supernova remnant is not known so far. We estimated the pulsar kick velocity to be in the range of 1 000–2 000 km s$^{-1}$ for ages between 23 and 10 kyr. The X-ray counterpart found in Chandra data, CXOU J163802.6$-$471358, shows the same tail morphology as the radio source but is shorter by a factor of 10. The peak of the X-ray emission is offset from the peak of the radio total intensity (Stokes $\rm I$) emission by approximately 4.7$^{\prime\prime}$, but coincides well with circularly polarised (Stokes $\rm V$) emission. No infrared counterpart was found.
Harnessing the power of the presidency, Lyndon Baines Johnson required America to wrestle with its past. Together, the powerful social movements of the 1960s and his Great Society catalyzed a cycle of reckoning and discomfort that changed America until the war in Vietnam, and anger and angst about government, identity, and power brought it to an end. We’ve tried to forget LBJ and, in some cases, what his presidency achieved and helped unearth. But we ignore him at our peril. The Johnson years have much to teach us, as America in the 1960s and today’s America have much in common. America today, as in the 1960s, is tumultuous. Armed with our memories and different conceptions of how we got here, we’re struggling to define our problems and the answers appear unknowable and out of reach. But instead of actively looking away from the past, we can choose to learn from it. Remembering Lyndon Johnson and his presidency – the good and the bad – offers us the opportunity to reposition government as an ally, not an enemy, and to acknowledge and confront the historically toxic relationship that binds power, politics, and American identity so we can move closer to our democratic aspirations.
Children with conduct problems and high callous-unemotional (CP+CU) traits are characterized by dampened emotional responding, limiting their ability for affective empathy and impacting the development of prosocial behaviors. However, research documenting this dampening in young children is sparse and findings vary, with attachment-related stimuli hypothesized to ameliorate deficits in emotional responding. Here we test emotional responsiveness across various emotion-eliciting stimuli using multiple measures of emotional responsiveness (behavioral, physiological, self-reported) and attention, in young children aged 2–8 years (M age = 5.37), with CP+CU traits (CP+CU; n = 36), CPs and low CU traits (CP−CU; n = 82) and a community control sample (CC; n = 27). We found no evidence that attachment-related stimulus ameliorated deficits in emotional responding. Rather, at a group level we found a consistent pattern of reduced responding across all independent measures of responsiveness for children with CP+CU compared to the CC group. Few differences were found between CP+CU and CP−CU groups. When independent measures were standardized and included in a regression model predicting to CU trait score, higher CU traits were associated with reduced emotional responding, demonstrating the importance of multimodal measurement of emotional responsiveness when investigating the impact of CU traits in young children.
Recent research in American politics demonstrates that despite gender-based partisan sorting, gender gaps in policy preferences persist within political parties—particularly among Republicans. Republican women report significantly more moderate views than their male counterparts across a range of policy areas. These gaps are largely attributable to gender differences in beliefs about the appropriate scope of government and attitudes toward gender-based inequality. Arguably, gender has become a more salient feature of American elections in recent years, and this heightened salience raises questions about whether these within-party gender gaps are stable over time or vary across campaign contexts. We use survey data from the 2012 and 2016 American National Election Study to evaluate whether gender gaps in policy preferences are stable across elections or if the 2016 election context affected the magnitude of gender differences in policy preferences. We find that gender gaps in policy preferences within political parties are fairly stable across the two electoral periods.
Much of our current understanding about novel coronavirus disease 2019 (COVID-19) comes from hospitalised patients. However, the spectrum of mild and subclinical disease has implications for population-level screening and control. Forty-nine participants were recruited from a group of 99 adults repatriated from a cruise ship with a high incidence of COVID-19. Respiratory and rectal swabs were tested by polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Sera were tested for anti-SARS-CoV-2 antibodies by enzyme-linked immunosorbent assay (ELISA) and microneutralisation assay. Symptoms, viral shedding and antibody response were examined. Forty-five participants (92%) were considered cases based on either positive PCR or positive ELISA for immunoglobulin G. Forty-two percent of cases were asymptomatic. Only 15% of symptomatic cases reported fever. Serial respiratory and rectal swabs were positive for 10% and 5% of participants respectively about 3 weeks after median symptom onset. Cycle threshold values were high (range 31–45). Attempts to isolate live virus were unsuccessful. The presence of symptoms was not associated with demographics, comorbidities or antibody response. In closed settings, incidence of COVID-19 could be almost double that suggested by symptom-based screening. Serology may be useful in diagnosis of mild disease and in aiding public health investigations.
Magnetised plasma turbulence can have a multiscale character: instabilities driven by mean temperature gradients drive turbulence at the disparate scales of the ion and the electron gyroradii. Simulations of multiscale turbulence, using equations valid in the limit of infinite scale separation, reveal novel cross-scale interaction mechanisms in these plasmas. In the case that both long-wavelength (ion-gyroradius-scale) and short-wavelength (electron-gyroradius-scale) linear instabilities are driven far from marginal stability, we show that the short-wavelength instabilities are suppressed by interactions with long-wavelength turbulence. Two novel effects contributed to the suppression: parallel-to-the-field-line shearing by the long-wavelength ${{\boldsymbol {E}} \times \boldsymbol {B}}$ flows, and the modification of the background density gradient by the piece of the long-wavelength electron adiabatic response with parallel-to-the-field-line variation. In contrast, simulations of multiscale turbulence where instabilities at both scales are driven near marginal stability demonstrate that when the long-wavelength turbulence is sufficiently collisional and zonally dominated the effect of cross-scale interaction can be parameterised solely in terms of the local modifications to the mean density and temperature gradients. We discuss physical arguments that qualitatively explain how a change in equilibrium drive leads to the observed transition in the impact of the cross-scale interactions.
Velvetleaf is an economically important weed in popcorn production fields in Nebraska. Many PRE herbicides in popcorn have limited residual activity or provide partial velvetleaf control. There are a limited number of herbicides applied POST in popcorn compared with field corn, necessitating the evaluation of POST herbicides for control of velvetleaf. The objectives of this study were to (1) evaluate the efficacy and crop safety of labeled POST herbicides for controlling velvetleaf that survived S-metolachlor/atrazine applied PRE and (2) determine the effect of velvetleaf height on POST herbicide efficacy, popcorn injury, and yield. Field experiments were conducted in 2018 and 2019 near Clay Center, Nebraska. The experiments were arranged in a split-plot design with four replications. The main plot treatments were velvetleaf height (≤15 cm and ≤30 cm) and subplot treatments included a no-POST herbicide control, and 11 POST herbicide programs. Fluthiacet-methyl, fluthiacet-methyl/mesotrione, carfentrazone-ethyl, dicamba, and dicamba/diflufenzopyr provided greater than 96% velvetleaf control 28 d after treatment (DAT), reduced velvetleaf density to fewer than 7 plants m−2, achieved 99% to 100% biomass reduction, and had no effect on popcorn yield. Herbicide programs tested in this study provided greater than 98% control of velvetleaf 28 DAT in 2019. Most POST herbicide programs in this study provided greater than 90% control of up to 15 cm and up to 30 cm velvetleaf and no differences between velvetleaf heights in density, biomass reduction, or popcorn yield were observed, except with topramezone and nicosulfuron/mesotrione 28 DAT in 2018. On the basis of contrast analysis, herbicide programs with fluthiacet-methyl or dicamba provided better control than herbicide programs without them at 28 DAT in 2018. It is concluded that POST herbicides are available for control of velvetleaf up to 30-cm tall in popcorn production fields.
The search for life in the Universe is a fundamental problem of astrobiology and modern science. The current progress in the detection of terrestrial-type exoplanets has opened a new avenue in the characterization of exoplanetary atmospheres and in the search for biosignatures of life with the upcoming ground-based and space missions. To specify the conditions favourable for the origin, development and sustainment of life as we know it in other worlds, we need to understand the nature of global (astrospheric), and local (atmospheric and surface) environments of exoplanets in the habitable zones (HZs) around G-K-M dwarf stars including our young Sun. Global environment is formed by propagated disturbances from the planet-hosting stars in the form of stellar flares, coronal mass ejections, energetic particles and winds collectively known as astrospheric space weather. Its characterization will help in understanding how an exoplanetary ecosystem interacts with its host star, as well as in the specification of the physical, chemical and biochemical conditions that can create favourable and/or detrimental conditions for planetary climate and habitability along with evolution of planetary internal dynamics over geological timescales. A key linkage of (astro)physical, chemical and geological processes can only be understood in the framework of interdisciplinary studies with the incorporation of progress in heliophysics, astrophysics, planetary and Earth sciences. The assessment of the impacts of host stars on the climate and habitability of terrestrial (exo)planets will significantly expand the current definition of the HZ to the biogenic zone and provide new observational strategies for searching for signatures of life. The major goal of this paper is to describe and discuss the current status and recent progress in this interdisciplinary field in light of presentations and discussions during the NASA Nexus for Exoplanetary System Science funded workshop ‘Exoplanetary Space Weather, Climate and Habitability’ and to provide a new roadmap for the future development of the emerging field of exoplanetary science and astrobiology.
Understanding the critical time of weed removal (CTWR) is necessary for designing effective weed management programs in popcorn production that do not result in yield reduction. The objective of this study was to determine the CTWR in popcorn with and without a premix of atrazine and S-metolachlor applied PRE. Field experiments were conducted at the University of Nebraska–Lincoln, South Central Agricultural Laboratory near Clay Center, NE in 2017 and 2018. The experiment was laid out in a split-plot design with PRE herbicide as the main plot and weed removal timing as the subplot. Main plots included no herbicide or atrazine/S-metolachlor applied PRE. Subplot treatments included a weed-free control, a non-treated control, and weed removal timing at V3, V6, V9, V15, and R1 popcorn growth stages and then kept weed free throughout the season. A four-parameter log-logistic function was fitted to percentage popcorn yield loss and growing degree days separately to each main plot. The number of growing degree days, when 5% yield loss was achieved, was extracted from the model and compared between main plots. The CTWR was from the V4 to V5 popcorn growth stage in absence of PRE herbicide. With atrazine/S-metolachlor applied PRE, the CTWR was delayed until V10 to V15. It is concluded that, to avoid yield loss, weeds must be controlled before the V4 popcorn growth stage when no PRE herbicide is applied, and PRE herbicide, such as atrazine/S-metolachlor in this study, can delay the CTWR until the V10 growth stage.
Widespread and repeated use of glyphosate resulted in an increase in glyphosate-resistant (GR) weeds. This led to an urgent need for diversification of weed control programs and use of PRE herbicides with alternative sites of action. Field experiments were conducted over a 4-yr period (2015 to 2018) across three locations in Nebraska to evaluate the effects of PRE-applied herbicides on critical time for weed removal (CTWR) in GR soybean. The studies were laid out in a split-plot arrangement with herbicide regime as the main plot and weed removal timing as the subplot. The herbicide regimes used were either no PRE or premix of either sulfentrazone plus imazethapyr (350 + 70 g ai ha−1) or saflufenacil plus imazethapyr plus pyroxasulfone (26 + 70 + 120 g ai ha−1). The weed removal timings were at V1, V3, V6, R2, and R5 soybean stages, with weed-free and weedy season-long checks. Weeds were removed by application of glyphosate (1,400 g ae ha−1) or by hoeing. The results across all years and locations suggested that the use of PRE herbicides delayed CTWR in soybean. In particular, the CTWR without PRE herbicides was determined to be around the V1 to V2 (14 to 21 d after emergence [DAE]) growth stage, depending on the location and weed pressure. The use of PRE-applied herbicides delayed CTWR from about the V4 (28 DAE) stage up to the R5 (66 DAE) stage. These results suggest that the use of PRE herbicides in GR soybean could delay the need for POST application of glyphosate by 2 to 5 wk, thereby reducing the need for multiple applications of glyphosate during the growing season. Additionally, the use of PRE herbicides could provide additional modes of action needed to manage GR weeds in GR soybean.
This article presents findings from a study that evaluated the impact of an Australian sustainability initiative, with a view to unravelling the realities of teachers’ implementation approaches. The paper outlines a study that reviews a government initiative in early years, primary and secondary educational settings that uses the Data Collection, Storage and Visualisations System (DCSVS) aimed at enhancing sustainability awareness and embedding sustainability as part of everyday practice in schools and early childhood services. It was also intended to offer school leaders, teachers and students avenues to engage with their consumption of natural resources. This in turn was anticipated to increase awareness about conservation, with the long-term aim to engage with the broader themes of sustainability. This article focuses on the role of teachers’ identities in enacting these policy initiatives. It highlights teachers’ enactment of the policies, the crucial role of school leaders in the process, as well as the deeper connections between curriculum and pedagogy.
SNP in the vitamin D receptor (VDR) gene is associated with risk of lower respiratory infections. The influence of genetic variation in the vitamin D pathway resulting in susceptibility to upper respiratory infections (URI) has not been investigated. We evaluated the influence of thirty-three SNP in eleven vitamin D pathway genes (DBP, DHCR7, RXRA, CYP2R1, CYP27B1, CYP24A1, CYP3A4, CYP27A1, LRP2, CUBN and VDR) resulting in URI risk in 725 adults in London, UK, using an additive model with adjustment for potential confounders and correction for multiple comparisons. Significant associations in this cohort were investigated in a validation cohort of 737 children in Manchester, UK. In all, three SNP in VDR (rs4334089, rs11568820 and rs7970314) and one SNP in CYP3A4 (rs2740574) were associated with risk of URI in the discovery cohort after adjusting for potential confounders and correcting for multiple comparisons (adjusted incidence rate ratio per additional minor allele ≥1·15, Pfor trend ≤0·030). This association was replicated for rs4334089 in the validation cohort (Pfor trend=0·048) but not for rs11568820, rs7970314 or rs2740574. Carriage of the minor allele of the rs4334089 SNP in VDR was associated with increased susceptibility to URI in children and adult cohorts in the United Kingdom.
Spherical coordinate systems, which are ubiquitous in astronomy, cannot be shown without distortion on flat, two-dimensional surfaces. This poses challenges for the two complementary phases of visual exploration—making discoveries in data by looking for relationships, patterns, or anomalies—and publication—where the results of an exploration are made available for scientific scrutiny or communication. This is a long-standing problem, and many practical solutions have been developed. Our allskyVR approach provides a workflow for experimentation with commodity virtual reality head-mounted displays. Using the free, open source s2plot programming library, and the A-FrameWebVR browser-based framework, we provide a straightforward way to visualise all-sky catalogues on a user-centred, virtual celestial sphere. The allskyVR distribution contains both a quickstart option, complete with a gaze-based menu system, and a fully customisable mode for those who need more control of the immersive experience. The software is available for download from https://github.com/cfluke/allskyVR.
Treatment of medical patients with the inflammatory cytokine, interferon-α (IFN-α), is frequently associated with the development of clinical depressive symptomatology. Several important biological correlates of the effect of IFN-α on mood have been described, but the neuropsychological changes associated with IFN-α treatment are largely unexplored. The aim of the present preliminary study was to assess the effect of IFN-α on measures of emotional processing.
Method
We measured changes in emotional processing over 6–8 weeks in 17 patients receiving IFN-α as part of their treatment for hepatitis C virus infection. Emotional processing tasks included those which have previously been shown to be sensitive to the effects of depression and antidepressant treatment, namely facial expression recognition, emotional categorisation and the dot probe attentional task.
Results
Following IFN-α, patients were more accurate at detecting facial expressions of disgust; they also showed diminished attentional vigilance to happy faces. IFN-α produced the expected increases in scores on depression rating scales, but there was no correlation between these scores and the changes in emotional processing.
Conclusions
Our preliminary findings suggest that IFN-α treatment produces negative biases in emotional processing, and this effect is not simply a consequence of depression. It is possible that increased recognition of disgust may represent a neuropsychological marker of depressive disorders related to inflammation.