Characterising dust emission events from long-term surface observations in northern Africa

Dust plays multiple important roles in the Earth system with emissions from northern Africa contributing on the order of 60% to the global total. Current model estimates of annual dust production from this crucial region vary by a factor of up to 5. This low agreement between models is to a great extent due to differences in the representation of near-surface winds. One barrier to better understanding of wind processes is the sparse observation network in northern Africa combined with regionally varying, but not necessarily documented, reporting procedures that lead to uncertainties and biases. Previous studies have utilised long-term station observations of visibility over this region to investigate dust climatology, but this work is the first to focus specifically on emission, based on quality-controlled reports from station observers and measurements of 10 m wind-speed. The interannual, seasonal and diurnal cycles of dust emission frequency (FDE), as well as trends, are investigated using existing and new analysis methods, such as the estimation of emission thresholds. Spatially, it is shown that threshold wind-speeds for dust emission are highest in northern Algeria and lowest in Sudan and around the latitude band 16◦N - 21◦N. FDE peaks in spring at most stations, while in the Sahel seasonal cycles vary between stations depending on their proximity to the Saharan Heat Low, and as a result of seasonal exposure to both the summer monsoon and winter Harmattan. Seasonally, FDE is largely controlled by changes in strong winds, rather than changes in emission thresholds. The relative contribution of different wind-speeds to dust uplift are investigated using the observed winds and calculated thresholds. Case studies and field campaign data are analysed to determine the plausibility of SYNOP high-wind reports. In northern regions, 50% of uplift is associated with high winds which occur only 0.3% - 0.5% of the time. This contrasts with an occurrence range of 0.7% - 2.5% for southern regions. Winds of 12 – 15 ms−1 contribute the most to northern total DUP, while in the south the range is lower at 7-11 ms−1. A percentage occurrence of 0.3% equates to only 5.5 events per year. Previous studies have documented changes in the dust output from northern Africa on interannual to decadal time scales, though the reasons for this variability are still debated. This study shows that the likely contributors to an observed decreasing trend in FDE are changes in circulation patterns, changes to the Bowen ratio and, most significantly, the effect of a change in roughness on wind-speed as a result of a greening of the Sahel. This work forms a base for further investigations into mechanisms for dust emission in northern Africa and their relative importance, as well as providing reference material for model and reanalysis evaluation

Phase transitions in 3-dimensional Dirac semi-metals using Schwinger-Dyson equations

We study the semi-metal/insulator quantum phase transition in three-dimensional Dirac semi-metals by solving a set of Schwinger-Dyson equations. We study the effect of an anisotropic fermion velocity on the critical coupling of the transition. We consider the influence of several different approximations that are commonly used in the literature and show that results for the critical coupling change considerably when some of these approximations are relaxed. Most importantly, the nature of the dependence of the critical coupling on the anisotropy depends strongly on the approximations that are used for the photon polarization tensor. On the one hand, this means that calculations that include full photon dynamics are necessary to answer even the basic question of whether the critical coupling increases or decreases with anisotropy. On the other hand, our results mean that it is possible that anisotropy could provide a mechanism to promote dynamical gap generation in realistic three-dimensional Dirac semi-metallic materials.Comment: 24 pages, 8 figure

Unique Rabin-Williams Signature Scheme Decryption

Abstract. The extremely efficient Rabin-Williams signature scheme relies on decryption of a quadratic equation in order to retrieve the original message. Customarily, square roots are found using the Chinese Remainder Theorem. This can be done in polynomial time, but generally produces four options for the correct message which must be analyzed to determine the correct one. This paper resolves the problem of efficient deterministic decryption to the correct message modulo $p^2q$ by establishing conditions on the primes $p$ and $q$ as well as on any legitimate message. We do this using the CRT modulo pq to find four roots. We show that the correct root (initial message) is the only one of these four which is in our allowed message set (it is in fact the smallest of the four integers) and which satisfies a quadratic equation modulo $p^2q$; no additional work is required to eliminate the others. As a result, we propose what we believe is now the most efficient version of R-W signature scheme decryption

Glasma properties in small proper time expansion

In a series of works by two of us, various characteristics of the glasma from the earliest phase of relativistic heavy-ion collisions have been studied using a proper time expansion. These characteristics include: energy density, longitudinal and transverse pressures, collective flow, angular momentum and parameters of jet quenching. In this paper we extend the proper time interval where our results are reliable by working at higher order in the expansion. We also generalize our previous study of jet quenching by extending our calculations to consider inhomogeneous glasma. Inhomogeneities are an important aspect of physically realistic systems that are difficult to include in calculations and are frequently ignored.Comment: 22 pages, 13 figure

Neighbourhood walkability, road density and socio-economic status in Sydney, Australia

Background Planning and transport agencies play a vital role in influencing the design of townscapes, travel modes and travel behaviors, which in turn impact on the walkability of neighbourhoods and residents\u27 physical activity opportunities. Optimising neighbourhood walkability is desirable in built environments, however, the population health benefits of walkability may be offset by increased exposure to traffic related air pollution. This paper describes the spatial distribution of neighbourhood walkability and weighted road density, a marker for traffic related air pollution, in Sydney, Australia. As exposure to air pollution is related to socio-economic status in some cities, this paper also examines the spatial distribution of weighted road density and walkability by socio-economic status (SES). Methods We calculated walkability, weighted road density (as a measure of traffic related air pollution) and SES, using predefined and validated measures, for 5858 Sydney neighbourhoods, representing 3.6 million population. We overlaid tertiles of walkability and weighted road density to define sweet-spots (high walkability-low weighted road density), and sour- spots (low walkability-high weighted road density) neighbourhoods. We also examined the distribution of walkability and weighted road density by SES quintiles. Results Walkability and weighted road density showed a clear east-west gradient across the region. Our study found that only 4 % of Sydney\u27s population lived in sweet-spot neighbourhoods with high walkability and low weighted road density (desirable), and these tended to be located closer to the city centre. A greater proportion of neighbourhoods had health limiting attributes of high weighted road density or low walkability (about 20 % each), and over 5 % of the population lived in sour-spot neighbourhoods with low walkability and high weighted road density (least desirable). These neighbourhoods were more distant from the city centre and scattered more widely. There were no linear trends between walkability/weighted road density and neighbourhood SES. Conclusions Our walkability and weighted road density maps and associated analyses by SES can help identify neighbourhoods with inequalities in health-promoting or health-limiting environments. Planning agencies should seek out opportunities for increased neighbourhood walkability through improved urban development and transport planning, which simultaneously minimizes exposure to traffic related air pollution

Bifidobacterium breve MRx0004 protects against airway inflammation in a severe asthma model by suppressing both neutrophil and eosinophil lung infiltration

All authors were employees of (or in the case of MID, seconded full-time to) 4D Pharma Research Ltd while engaged in the research project. This work was supported by funding provided by 4D Pharma PLC. 4D Pharma Research Ltd owns a family of patent applications which are pending internationally which are derived from International Patent Publication No. WO2016/203223 which protect the treatment of severe asthma using MRx0004. George Grant, Angela Patterson, Imke Mulder, Seanin McCluskey and Emma Raftis are named as inventors for this patent family. The authors declare no other competing interests.Peer reviewedPublisher PD

Interventions to support the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic: a mixed methods systematic review

Background Evidence from disease epidemics shows that healthcare workers are at risk of developing short‐ and long‐term mental health problems. The World Health Organization (WHO) has warned about the potential negative impact of the COVID‐19 crisis on the mental well‐being of health and social care professionals. Symptoms of mental health problems commonly include depression, anxiety, stress, and additional cognitive and social problems; these can impact on function in the workplace. The mental health and resilience (ability to cope with the negative effects of stress) of frontline health and social care professionals ('frontline workers' in this review) could be supported during disease epidemics by workplace interventions, interventions to support basic daily needs, psychological support interventions, pharmacological interventions, or a combination of any or all of these. Objectives Objective 1: to assess the effects of interventions aimed at supporting the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic. Objective 2: to identify barriers and facilitators that may impact on the implementation of interventions aimed at supporting the resilience and mental health of frontline health and social care professionals during and after a disease outbreak, epidemic or pandemic. Search methods On 28 May 2020 we searched the Cochrane Database of Systematic Reviews, CENTRAL, MEDLINE, Embase, Web of Science, PsycINFO, CINAHL, Global Index Medicus databases and WHO Institutional Repository for Information Sharing. We also searched ongoing trials registers and Google Scholar. We ran all searches from the year 2002 onwards, with no language restrictions. Selection criteria We included studies in which participants were health and social care professionals working at the front line during infectious disease outbreaks, categorised as epidemics or pandemics by WHO, from 2002 onwards. For objective 1 we included quantitative evidence from randomised trials, non‐randomised trials, controlled before‐after studies and interrupted time series studies, which investigated the effect of any intervention to support mental health or resilience, compared to no intervention, standard care, placebo or attention control intervention, or other active interventions. For objective 2 we included qualitative evidence from studies that described barriers and facilitators to the implementation of interventions. Outcomes critical to this review were general mental health and resilience. Additional outcomes included psychological symptoms of anxiety, depression or stress; burnout; other mental health disorders; workplace staffing; and adverse events arising from interventions. Data collection and analysis Pairs of review authors independently applied selection criteria to abstracts and full papers, with disagreements resolved through discussion. One review author systematically extracted data, cross‐checked by a second review author. For objective 1, we assessed risk of bias of studies of effectiveness using the Cochrane 'Risk of bias' tool. For objective 2, we assessed methodological limitations using either the CASP (Critical Appraisal Skills Programme) qualitative study tool, for qualitative studies, or WEIRD (Ways of Evaluating Important and Relevant Data) tool, for descriptive studies. We planned meta‐analyses of pairwise comparisons for outcomes if direct evidence were available. Two review authors extracted evidence relating to barriers and facilitators to implementation, organised these around the domains of the Consolidated Framework of Implementation Research, and used the GRADE‐CERQual approach to assess confidence in each finding. We planned to produce an overarching synthesis, bringing quantitative and qualitative findings together. Main results We included 16 studies that reported implementation of an intervention aimed at supporting the resilience or mental health of frontline workers during disease outbreaks (severe acute respiratory syndrome (SARS): 2; Ebola: 9; Middle East respiratory syndrome (MERS): 1; COVID‐19: 4). Interventions studied included workplace interventions, such as training, structure and communication (6 studies); psychological support interventions, such as counselling and psychology services (8 studies); and multifaceted interventions (2 studies). Objective 1: a mixed‐methods study that incorporated a cluster‐randomised trial, investigating the effect of a work‐based intervention, provided very low‐certainty evidence about the effect of training frontline healthcare workers to deliver psychological first aid on a measure of burnout. Objective 2: we included all 16 studies in our qualitative evidence synthesis; we classified seven as qualitative and nine as descriptive studies. We identified 17 key findings from multiple barriers and facilitators reported in studies. We did not have high confidence in any of the findings; we had moderate confidence in six findings and low to very low confidence in 11 findings. We are moderately confident that the following two factors were barriers to intervention implementation: frontline workers, or the organisations in which they worked, not being fully aware of what they needed to support their mental well‐being; and a lack of equipment, staff time or skills needed for an intervention. We are moderately confident that the following three factors were facilitators of intervention implementation: interventions that could be adapted for local needs; having effective communication, both formally and socially; and having positive, safe and supportive learning environments for frontline workers. We are moderately confident that the knowledge or beliefs, or both, that people have about an intervention can act as either barriers or facilitators to implementation of the intervention. Authors' conclusions There is a lack of both quantitative and qualitative evidence from studies carried out during or after disease epidemics and pandemics that can inform the selection of interventions that are beneficial to the resilience and mental health of frontline workers. Alternative sources of evidence (e.g. from other healthcare crises, and general evidence about interventions that support mental well‐being) could therefore be used to inform decision making. When selecting interventions aimed at supporting frontline workers' mental health, organisational, social, personal, and psychological factors may all be important. Research to determine the effectiveness of interventions is a high priority. The COVID‐19 pandemic provides unique opportunities for robust evaluation of interventions. Future studies must be developed with appropriately rigorous planning, including development, peer review and transparent reporting of research protocols, following guidance and standards for best practice, and with appropriate length of follow‐up. Factors that may act as barriers and facilitators to implementation of interventions should be considered during the planning of future research and when selecting interventions to deliver within local settings

Long-term exposure to low concentrations of air pollutants and hospitalisation for respiratory diseases:A prospective cohort study in Australia

Background: Short- and long-term spatiotemporal variation in exposure to air pollution is associated with respiratory morbidity in areas with moderate-to-high level of air pollution, but very few studies have examined whether these associations also exist in areas with low level exposure. Objectives: We assessed the association between spatial variation in long-term exposure to PM and NO and hospitalisation for all respiratory diseases, asthma, chronic obstructive pulmonary disease (COPD), and pneumonia, in older adults residing in Sydney, Australia, a city with low-level concentrations. Methods: We recorded data on hospitalisations for 100,084 participants, who were aged >45 years at entry in 2006–2009 until June 2014. Annual NO and PM concentrations were estimated for the participants’ residential addresses and Cox proportional hazards regression was used to model the association between exposure to air pollutants and first episode of hospitalisation, controlling for personal and area level covariates. We further investigated the shape of the exposure-response association and potential effect modification by age, sex, education level, smoking status, and BMI. Results: NO and PM annual mean exposure estimates were 17.5 μg·m and 4.5 μg·m respectively. NO and PM was positively, although not significantly, associated with asthma. The adjusted hazard ratio for a 1 μg·m increase in PM was 1.08, 95% confidence interval 0.89–1.30. The adjusted hazard ratio for a 5 μg·m increase in NO was 1.03, 95% confidence interval 0.88–1.19. We found no positive statistically significant associations with hospitalisation for all respiratory diseases, and pneumonia while negative associations were observed with COPD. Conclusions: We found weak positive associations of exposure to air pollution with hospitalisation for asthma while there was no evidence of an association for all respiratory diseases

All-cause mortality and long-term exposure to low level air pollution in the ‘45 and up study’ cohort, Sydney, Australia, 2006–2015

Epidemiological studies show that long-term exposure to ambient air pollution reduces life expectancy. Most studies have been in environments with relatively high concentrations such as North America, Europe and Asia. Associations at the lower end of the concentration-response function are not well defined.We assessed associations between all-cause mortality and exposure to annual average particulate matte

Evaluation of the impact of an augmented model of The Productive Ward: Releasing Time to Care on staff and patient outcomes: a naturalistic stepped-wedge trial

Background: Improving the quality and efficiency of healthcare is an international priority. A range of complex ward based quality initiatives have been developed over recent years, perhaps the most influential programme has been Productive Ward: Releasing Time to Care. The programme aims to improve work processes and team efficiency with the aim of ‘releasing time’, which would be used to increase time with patients ultimately improving patient care, although this does not form a specific part of the programme. This study aimed to address this and evaluate the impact using recent methodological advances in complex intervention evaluation design.Method: The objective of this study was to assess the impact of an augmented version of The Productive Ward: Releasing Time to Care on staff and patient outcomes. The design was a naturalistic stepped-wedge trial. The setting included fifteen wards in two acute hospitals in a Scottish health board region. The intervention was the Productive Ward: Releasing Time to Care augmented with practice development transformational change methods that focused on staff caring behaviours, teamwork and patient feedback. The primary outcomes included nurses’ shared philosophy of care, nurse emotional exhaustion, and patient experience of nurse communication. Secondary outcomes covered additional key dimensions of staff and patient experience and outcomes and frequency of emergency admissions for same diagnosis within 6 months of discharge.Results: We recruited 691 patients, 177 nurses and 14 senior charge nurses. We found statistically significant improvements in two of the study’s three primary outcomes: patients’ experiences of nurse communication (Effect size=0.15, 95% CI; 0.05 to 0.24), and nurses’ shared philosophy of care (Effect size =0.42, 95% CI; 0.14 to 0.70). There were also significant improvements in secondary outcomes: patients’ overall rating of ward quality; nurses’ positive affect; and items relating to nursing team climate. We found no change in frequency of emergency admissions within six months of discharge.Conclusions: We found evidence that the augmented version of The Productive Ward: Releasing Time to Care Intervention was successful in improving a number of dimensions of nurse experience and ward culture, in addition to improved patient experience and evaluations of the quality of care received. Despite these positive summary findings across all wards, intervention implementation appeared to vary between wards. By addressing the contextual factors, which may influence these variations, and tailoring some elements of the intervention, it is likely that greater improvements could be achieved