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The impact of heterogeneous uptake of HO2 on aerosol surfaces on radical concentrations and the O3 production regime in Beijing in summertime was investigated. The uptake coefficient of HO2 onto aerosol surfaces, γHO2, was calculated for the AIRPRO campaign in Beijing, in summer 2017, as a function of measured aerosol soluble copper concentration, [Cu2+]eff, aerosol liquid water content, [ALWC], and particulate matter concentration, [PM]. An average γHO2 across the entire campaign of 0.070±0.035 was calculated, with values ranging from 0.002 to 0.15, and found to be significantly lower than the value of γHO2=0.2, commonly used in modelling studies. Using the calculated γHO2 values for the summer AIRPRO campaign, OH, HO2 and RO2 radical concentrations were modelled using a box model incorporating the Master Chemical Mechanism (v3.3.1), with and without the addition of γHO2, and compared to the measured radical concentrations. The rate of destruction analysis showed the dominant HO2 loss pathway to be HO2 + NO for all NO concentrations across the summer Beijing campaign, with HO2 uptake contributing % to the total loss of HO2 on average. This result for Beijing summertime would suggest that under most conditions encountered, HO2 uptake onto aerosol surfaces is not important to consider when investigating increasing O3 production with decreasing [PM] across the North China Plain. At low [NO], however, i.e. ppb, which was often encountered in the afternoons, up to 29 % of modelled HO2 loss was due to HO2 uptake on aerosols when calculated γHO2 was included, even with the much lower γHO2 values compared to γHO2= 0.2, a result which agrees with the aerosol-inhibited O3 regime recently proposed by Ivatt et al. (2022). As such it can be concluded that in cleaner environments, away from polluted urban centres where HO2 loss chemistry is not dominated by NO but where aerosol surface area is high still, changes in PM concentration and hence aerosol surface area could still have a significant effect on both overall HO2 concentration and the O3 production regime. Using modelled radical concentrations, the absolute O3 sensitivity to NOx and volatile organic compounds (VOCs) showed that, on average across the summer AIRPRO campaign, the O3 production regime remained VOC-limited, with the exception of a few days in the afternoon when the NO mixing ratio dropped low enough for the O3 regime to shift towards being NOx-limited. The O3 sensitivity to VOCs, the dominant regime during the summer AIRPRO campaign, was observed to decrease and shift towards a NOx-sensitive regime both when NO mixing ratio decreased and with the addition of aerosol uptake. This suggests that if [NOx] continues to decrease in the future, ozone reduction policies focussing solely on NOx reductions may not be as efficient as expected if [PM] and, hence, HO2 uptake to aerosol surfaces continue to decrease. The addition of aerosol uptake into the model, for both the γHO2 calculated from measured data and when using a fixed value of γHO2=0.2, did not have a significant effect on the overall O3 production regime across the campaign. While not important for this campaign, aerosol uptake could be important for areas of lower NO concentration that are already in a NOx-sensitive regime.

The photostationary state (PSS) equilibrium between NO and NO2 is reached within minutes in the atmosphere and can be described by the PSS parameter, φ. Deviations from expected values of φ have previously been used to infer missing oxidants in diverse locations, from highly polluted regions to the extremely clean conditions observed in the remote marine boundary layer (MBL), and have been interpreted as missing understanding of fundamental photochemistry. Here, contrary to these previous observations, we observe good agreement between PSS-derived NO2 ([NO2]PSS ext.), calculated from measured NO, O3, and jNO2 and photochemical box model predictions of peroxy radicals (RO2 and HO2), and observed NO2 ([NO2]Obs.) in extremely clean air containing low levels of CO ( ppbV) and VOCs (volatile organic compounds). However, in clean air containing small amounts of aged pollution (CO > 100 ppbV), we observed higher levels of NO2 than inferred from the PSS, with [NO2]Obs. / [NO2]PSS ext. of 1.12–1.68 (25th–75th percentile), implying underestimation of RO2 radicals by 18.5–104 pptV. Potential NO2 measurement artefacts have to be carefully considered when comparing PSS-derived NO2 to observed NO2, but we show that the NO2 artefact required to explain the deviation would have to be ∼ 4 times greater than the maximum calculated from known interferences. If the additional RO2 radicals inferred from the PSS convert NO to NO2 with a reaction rate equivalent to that of methyl peroxy radicals (CH3O2), then the calculated net ozone production rate (NOPR, ppbV h−1) including these additional oxidants is similar to the average change in O3 observed, within estimated uncertainties, once halogen oxide chemistry is accounted for. This implies that such additional peroxy radicals cannot be excluded as a missing oxidant in clean marine air containing aged pollution and that modelled RO2 concentrations are significantly underestimated under these conditions.

This study explores our ability to simulate the atmospheric chemistry stemming from isoprene emissions in pristine and polluted regions of the Amazon basin. We confront two atmospheric chemistry models – a global, Eulerian chemistry-climate model (UM-UKCA) and a trajectory-based Lagrangian model (CiTTyCAT) – with recent airborne measurements of atmospheric composition above the Amazon made during the SAMBBA campaign of 2012. The simulations with the two models prove relatively insensitive to the chemical mechanism employed; we explore one based on the Mainz Isoprene Mechanism, and an updated one that includes changes to the chemistry of first generation isoprene nitrates (ISON) and the regeneration of hydroxyl radicals via the formation of hydroperoxy-aldehydes (HPALDS) from hydroperoxy radicals (ISO2). In the Lagrangian model, the impact of increasing the spatial resolution of trace gas emissions employed from 3.75° × 2.5° to 0.1° × 0.1° varies from one flight to another, and from one chemical species to another. What consistently proves highly influential on our simulations, however, is the model framework itself – how the treatment of transport, and consequently mixing, differs between the two models. The lack of explicit mixing in the Lagrangian model yields variability in atmospheric composition more reminiscent of that exhibited by the measurements. In contrast, the combination of explicit (and implicit) mixing in the Eulerian model removes much of this variability but yields better agreement with the measurements overall. We therefore explore a simple treatment of mixing in the Lagrangian model that, drawing on output from the Eulerian model, offers a compromise between the two models. We use this Lagrangian/Eulerian combination, in addition to the separate Eulerian and Lagrangian models, to simulate ozone at a site in the boundary layer downwind of Manaus, Brazil. The Lagrangian/Eulerian combination predicts a value for an AOT40-like accumulated exposure metric of around 1000 ppbv h, compared to just 20 ppbv h with the Eulerian model. The model framework therefore has considerable bearing on our understanding of the frequency at which, and the duration for which, the rainforest is exposed to damaging ground-level ozone concentrations.

Research on two-dimensional (2D) materials, such as graphene and molybdenum disulfide (MoS2), now involves researchers worldwide, implementing cutting edge technology to study them. However, when considering using 2D materials in such promising applications, one of the major concerns is the mechanical failure, which remains heavily underexplored. In this work, we demonstrate the use of sequential and concurrent multiscale modeling to study the effect of various fracture modes on graphene and molybdenum disulfide (MoS2). Some of the fracture modes explored are pure tensile loading, shear loading, and a combination of tensile and shear loading and cyclic loading to investigate fatigue.

In this work, the kinematics and basic laws of micromorphic theory are briefly introduced. Then, constitutive equations for micromorphic thermo-visco-elastoplastic solids are rigorously derived. Finite element equations for the displacement, micromotion and temperature fields are formulated based on the principle of virtual work. As examples, three-dimensional, dynamic, finite strain, mixed mode fracture mechanics problems have been solved by a general purpose in-house developed code. Numerical results, including temperature, [Formula: see text] norms of stresses, plastic strains and micromotions, are presented and the physical meanings are discussed. This paper provides theoretical fundamentals to study the thermo-visco-elastic-plastic behaviors of micromorphic solids and constructs a numerical framework to study fracture mechanics of edge-crack problems.

The UK’s large atmospheric research aircraft is a converted BAe 146 operated by the Facility for Airborne Atmospheric Measurements (FAAM). With a range of 2000 nautical miles, the FAAM aircraft is capable of operating all over the world and it has taken part in science campaigns in over 30 different countries since 2004. The aircraft can fly as low as 50 feet over the sea and sustain flight at 100 feet high. The service ceiling is nearly 11 km high. Typically, flights will last anywhere between one and six hours, and we will carry up to 18 scientists onboard, who guide the mission and support the operation of up to 4 tonnes of scientific equipment. Currently, the aircraft is undergoing a £49 million mid-life upgrade (MLU) program, which will extend its lifetime to at least 2040. The three overarching objectives of the MLU are to:Safeguard the UK’s research capability – allowing the facility to meet the needs of the research community, enhance the range of services available, and respond to environmental emergencies.Provide frontier science capability – meeting new and existing research needs and supporting ground-breaking science discoveries, with a flexible and world-class airborne laboratory.Reduce environmental impact – maintaining and improving the performance of the facility, and minimising emissions and resource use from aircraft operation.Presented here will be a brief history of the aircraft operations, including example science outcomes from all flights all over the world. In addition, detail of the ongoing upgrades, in particular the new and cutting-edge measurement capability for gases, aerosols, clouds, radiation and meteorology. Also presented will be the expected reductions in environmental impact of the aircraft and how these will be monitored.

Concern over mental health and well-being is acute, particularly following stressful pandemic times, marked by social disconnection and loneliness. At risk is one’s sense of social belonging, a fundamental human need critical to human survival. We echo Holt-Lunstad’s (2022) call for prioritizing social factors when addressing public health during and in recovery from the pandemic, arguing that workplace supervisors and leaders can play an important role. As a workplace context, the military is especially focused on social relationships as service member employees face extreme health and safety challenges, not unlike other high risk first responder occupations. This study evaluated the efficacy of an evidence-based supportive-leadership training intervention targeting active-duty U.S. Army platoon leaders. The goal of the training was to increase service members’ social connectedness through leaders providing social support for psychological health and resilience, thereby decreasing loneliness. One hundred-four platoon leaders completed the 90-minute training that consisted of both in-person and computer-based components. Intervention effects were tested using an intent-to-treat approach and revealed a significant effect, whereby loneliness for service members who were randomized to the intervention group (N=118) was significantly reduced compared to loneliness reports for service members in the control group (N=158). Service members with higher baseline loneliness were more strongly and positively impacted by the supervisor training, reporting higher levels of emotional support and stigma-reduction behaviors from their leaders at 3 months post-baseline. In sum, these results suggest how workplaces and their leaders play a critical role in a national strategy to address Americans’ well-being.

Purpose: The purpose of this review article was to (a) scope the literature related to coaching caregivers of children with autism to provide an overview of current practices for assessment and intervention conducted via telepractice in collaboration with caregivers and (b) examine commonly reported challenges related to telepractice and potential solutions. Method: We conducted a search of relevant literature and identified seven articles that are related to the topic of caregiver involvement in remote assessments and interventions for children with autism. Results: Seven studies that include 10 caregiver-implemented interventions were identified. Researchers have used telepractice to conduct both assessments and interventions, and they generally reported having successful interactions with caregivers using different telepractice platforms. The most common telepractice modality was conducting live videoconferencing to provide services. These articles also contained rich information related to the commonly reported barriers and needs of caregivers to conduct telepractice, such as challenges in using telepractice technology and providing adequate training to caregivers. The studies also address different strategies researchers and professionals may utilize to alleviate these practical challenges to provide more streamlined telepractice services. Conclusions: Although there are challenges related to conducting assessments and interventions via telepractice, it was suggested that telepractice can be a supplement in delivering evidence-based interventions. As there are implications for future research and practice, we call for more research and practice to examine how professionals may optimize service delivery to caregivers.

Challenging behavior exhibited by young children with neurodevelopmental disabilities is known to negatively affect their optimal development and families’ quality of life. Although some support exists for English-speaking parents of children with autism who live in high-resource countries, it is scarce for others. Such disparity may also be heightened during the coronavirus disease 2019 (COVID-19) pandemic with its various societal restrictions. To mitigate the treatment gap, we developed and adapted a series of online training modules on behavioral principles and examined its effectiveness with 88 South Korean parents using a randomized controlled trial. We found significant interaction effects on increasing parents’ knowledge of behavioral principles, increasing positive parenting practices, and decreasing parental stress. Qualitative social validity data also indicated that parents were highly satisfied with the goals, procedures, and outcomes and that the program positively affected their parenting styles.

The irreversibility, temperature, and entropy are identified for an atomic system of solid material. Thermodynamics second law is automatically satisfied in the time evolution of molecular dynamics (MD). The irreversibility caused by an atom spontaneously moves from a non-stable equilibrium position to a stable equilibrium position. The process is dynamic in nature associated with the conversion of potential energy to kinetic energy and the dissipation of kinetic energy to the entire system. The forward process is less sensitive to small variation of boundary condition than reverse process, causing the time symmetry to break. Different methods to define temperature in molecular system are revisited with paradox examples. It is seen that the temperature can only be rigorously defined on an atom knowing its time history of velocity vector. The velocity vector of an atom is the summation of the mechanical part and the thermal part, the mechanical velocity is related to the global motion (translation, rotation, acceleration, vibration, etc.), the thermal velocity is related to temperature and is assumed to follow the identical random Gaussian distribution for all of its [Formula: see text], [Formula: see text] and [Formula: see text] component. The [Formula: see text]-velocity (same for [Formula: see text] or [Formula: see text]) versus time obtained from MD simulation is treated as a signal (mechanical motion) corrupted with random Gaussian distribution noise (thermal motion). The noise is separated from signal with wavelet filter and used as the randomness measurement. The temperature is thus defined as the variance of the thermal velocity multiply the atom mass and divided by Boltzmann constant. The new definition is equivalent to the Nose–Hover thermostat for a stationary system. For system with macroscopic acceleration, rotation, vibration, etc., the new definition can predict the same temperature as the stationary system, while Nose–Hover thermostat predicts a much higher temperature. It is seen that the new definition of temperature is not influenced by the global motion, i.e., translation, rotation, acceleration, vibration, etc., of the system. The Gibbs entropy is calculated for each atom by knowing normal distribution as the probability density function. The relationship between entropy and temperature is established for solid material.

Challenging behaviors exhibited by young children negatively affect development and may also prevent children from receiving appropriate education. These behaviors may also hinder positive family interactions and have a significant impact on parents and other family members. Although various parent training approaches exist to increase parents' capacity to address these challenging behaviors, many parents are reportedly not able to access training due to time and resource constraints. To address inequitable dissemination of information, we developed and piloted the use of the Challenging Behavior Online Modules with 10 parents of children with disabilities. In particular, we examined the feasibility of the Challenging Behavior Online Modules for increasing parents' knowledge and use of positive parenting practices with their young children. Parents reported satisfaction with the contents and delivery method of the intervention. Implications and directions for future research are also suggested.

Particulate nitrate ( pNO 3 − ) has long been considered a permanent sink for NO x (NO and NO 2 ), removing a gaseous pollutant that is central to air quality and that influences the global self-cleansing capacity of the atmosphere. Evidence is emerging that photolysis of pNO 3 − can recycle HONO and NO x back to the gas phase with potentially important implications for tropospheric ozone and OH budgets; however, there are substantial discrepancies in “renoxification” photolysis rate constants. Using aircraft and ground-based HONO observations in the remote Atlantic troposphere, we show evidence for renoxification occurring on mixed marine aerosols with an efficiency that increases with relative humidity and decreases with the concentration of pNO 3 − , thus largely reconciling the very large discrepancies in renoxification photolysis rate constants found across multiple laboratory and field studies. Active release of HONO from aerosol has important implications for atmospheric oxidants such as OH and O 3 in both polluted and clean environments.

This work developed the optimal and active control algorithms applicable to structural control for earthquake resistance. [Lewis, F. L., Vrabie, D. and Syrmos, V. L. [2012] Optimal Control (John Wiley & Sons)] developed a rigorous and comprehensive procedure for the derivation of an optimal control strategy based on the calculus of variation. This work is an application of Lewis’ formulation to the control of a structure for earthquake resistance. We developed a computer software which can be used to generate a dynamic model to simulate a planar structure and to construct the control law. This model also includes the tendon driven actuators, sensors and true history of earthquake excitation. The control law has two parts: (I) the feedback control which depends on the estimate state variables (Kalman filter) and (II) the record of the realistic earthquake excitation. The optimal control problem eventually leads to a two-point boundary value problem whose solution hinges on the knowledge of the entire history of the earthquake excitation. We employ true records of earthquake excitation as input. This approach enables one to solve the Riccati equations rigorously. Then, from the simulation results, one may study the relations between the control algorithm design and the characteristics (frequency, amplitude and duration) of earthquake excitation.

Flux measurements of nitrogen oxides (NOx) were made over London using airborne eddy covariance from a low-flying aircraft. Seven low-altitude flights were conducted over Greater London, performing multiple overpasses across the city during eight days in July 2014. NOx fluxes across the Greater London region (GLR) exhibited high heterogeneity and strong diurnal variability, with central areas responsible for the highest emission rates (20–30 mg m−2 h−1). Other high-emission areas included the M25 orbital motorway. The complexity of London's emission characteristics makes it challenging to pinpoint single emissions sources definitively using airborne measurements. Multiple sources, including road transport and residential, commercial and industrial combustion sources, are all likely to contribute to measured fluxes. Measured flux estimates were compared to scaled National Atmospheric Emissions Inventory (NAEI) estimates, accounting for monthly, daily and hourly variability. Significant differences were found between the flux-driven emissions and the NAEI estimates across Greater London, with measured values up to 2 times higher in Central London than those predicted by the inventory. To overcome the limitations of using the national inventory to contextualise measured fluxes, we used physics-guided flux data fusion to train environmental response functions (ERFs) between measured flux and environmental drivers (meteorological and surface). The aim was to generate time-of-day emission surfaces using calculated ERF relationships for the entire GLR; 98 % spatial coverage was achieved across the GLR at 400 m2 spatial resolution. All flight leg projections showed substantial heterogeneity across the domain, with high emissions emanating from Central London and major road infrastructure. The diurnal emission structure of the GLR was also investigated, through ERF, with the morning rush hour distinguished from lower emissions during the early afternoon. Overall, the integration of airborne fluxes with an ERF-driven strategy enabled the first independent generation of surface NOx emissions, at high resolution using an eddy-covariance approach, for an entire city region.

The ways caregivers perceive and respond to challenging behavior (CB) could depend, in part, on their cultural and ethnic backgrounds. Yet, limited research is available on the definitions, perceptions, and response strategies of CB across cultural groups, particularly among caregivers of young children with disabilities. In this exploratory multimethod study, data were collected from four diverse caregiver groups (i.e., Black, Korean American, Mexican American, and White) with young children with disabilities to understand (a) what behaviors they considered challenging and (b) how they responded to those behaviors. Data revealed similarities and differences in the types of behaviors reported and indicated caregivers rely on preplanned consequence strategies and unplanned responses.

Isoprene nitrates are important chemical species in the atmosphere which contribute to the chemical cycles that form ozone and secondary organic aerosol (SOA) with implications for climate and air quality. Accurate chemical mechanisms are important for the prediction of the atmospheric chemistry of species such as isoprene nitrates in chemical models. In recent years, studies into the chemistry of isoprene nitrates have resulted in the development of a range of mechanisms available for use in the simulation of atmospheric isoprene oxidation. This work uses a 0-D chemical box model to assess the ability of three chemically detailed mechanisms to predict the observed diurnal profiles of four groups of isoprene-derived nitrates in the summertime in the Chinese megacity of Beijing. An analysis of modelled C5H9NO5 isomers, including isoprene hydroperoxy nitrate (IPN) species, highlights the significant contribution of non-IPN species to the C5H9NO5 measurement, including the potentially large contribution of nitrooxy hydroxyepoxide (INHE). The changing isomer distribution of isoprene hydroxy nitrates (IHNs) derived from OH-initiated and NO3-initiated chemistry is discussed, as is the importance of up-to-date alkoxy radical chemistry for the accurate prediction of isoprene carbonyl nitrate (ICN) formation. All mechanisms under-predicted C4H7NO5 as predominately formed from the major isoprene oxidation products, methyl vinyl ketone (MVK) and methacrolein (MACR). This work explores the current capability of existing chemical mechanisms to accurately represent isoprene nitrate chemistry in urban areas significantly impacted by anthropogenic and biogenic chemical interactions. It suggests considerations to be taken when investigating isoprene nitrates in ambient scenarios, investigates the potential impact of varying isomer distributions on iodide chemical ionisation mass spectrometry (I−-CIMS) calibrations, and makes some proposals for the future development of isoprene mechanisms.

Fluxes of nitrogen oxides (NOx=NO+NO2) and carbon dioxide (CO2) were measured using eddy covariance at the British Telecommunications (BT) Tower in central London during the coronavirus pandemic. Comparing fluxes to those measured in 2017 prior to the pandemic restrictions and the introduction of the Ultra-Low Emissions Zone (ULEZ) highlighted a 73 % reduction in NOx emissions between the two periods but only a 20 % reduction in CO2 emissions and a 32 % reduction in traffic load. Use of a footprint model and the London Atmospheric Emissions Inventory (LAEI) identified transport and heat and power generation to be the two dominant sources of NOx and CO2 but with significantly different relative contributions for each species. Application of external constraints on NOx and CO2 emissions allowed the reductions in the different sources to be untangled, identifying that transport NOx emissions had reduced by >73 % since 2017. This was attributed in part to the success of air quality policy in central London but crucially due to the substantial reduction in congestion that resulted from pandemic-reduced mobility. Spatial mapping of the fluxes suggests that central London was dominated by point source heat and power generation emissions during the period of reduced mobility. This will have important implications on future air quality policy for NO2 which, until now, has been primarily focused on the emissions from diesel exhausts.

Parent-implemented autism interventions are considered empirically validated interventions and the use of telepractice in these interventions is reported as effective. However, little is known about the social validity assessments and outcomes of these interventions. The purpose of this review is to explore the current practices of conducting social validity assessment and reporting its outcomes within parent-implemented telepractice autism interventions.The 11 reviewed studies included caregivers as participants, telepractice intervention focusing on social communication outcomes of young autistic children, and were published in a peer-reviewed journal within the past five years.The researchers in the reviewed articles reported positive outcomes for parent-implemented telepractice autism interventions. Notably, however, information about social validity assessments of the interventions was limited. Researchers are encouraged to evaluate the social validity of interventions using multiple data sources and methods, and report on their findings as they relate to other types of data.

Although global prevalence of autism has grown substantially, researchers still report inequity in access to evidence-based interventions in many low-resource settings where majority of world’s children live. Capacity building of diverse stakeholders in low-resource settings has been suggested to be a potential way to mitigate low levels of access to resources; however, little is known about what these stakeholders consider as helpful strategies in capacity building. In this qualitative research, we conducted five focus groups with 30 Mongolian caregivers of children with autism and 15 individual interviews with professionals in Mongolia. Three themes emerged from this study, including (a) partnership, (b) advocacy, and (c) empowerment. Each theme also contained several categories. For example, partnerships included enhancing collaboration among stakeholders and collaboration with international development agencies; advocacy included parental and legislative advocacy; and empowerment included training for diverse stakeholders, including caregivers and professionals. Implications and directions for future research are also suggested. Lay abstract Prevalence of autism is increasing all around the globe, but there is still great inequity in accessing evidence-based interventions. Although the field of autism research has made great strides in identifying and establishing evidence-based interventions, dissemination and implementation of these interventions have been reported as inequitable. This inequity is especially highlighted in many low-resource settings, such as Mongolia. As a field, there is still much to be learned about what strategies are used by stakeholders in low-resource settings to build capacity and to mitigate the hardships. To gain a deeper understanding of strategies for capacity building within a low-resource setting, we conducted five focus groups with 30 Mongolian caregivers of children with autism and 15 individual interviews with various professionals who work in Mongolia. These stakeholders reported three main strategies, including (a) partnership, (b) advocacy, and (c) empowerment, which included several strategies and implications on capacity-building practices. Furthermore, the findings from this study may suggest important implications for future intervention research.

The importance of family engagement in their children’s education and treatment is emphasized by researchers, professional organizations, and legislatures. Providing services with caregivers via telepractice has gained more support and is becoming especially timely due to the current pandemic and social distancing requirements. Professionals, such as board-certified behavior analysts (BCBAs), who work with caregivers with children with disabilities may benefit from receiving professional development on strategies for building better rapport with caregivers and coaching them to bring about maximum clinical efficacy. The current pilot study replicated an earlier study by Meadan et al. to examine the effects of the Coaching Caregiver Professional Development (CoCarePD) intervention package, in which BCBAs received training and coaching from researchers via telepractice, on their caregiver coaching practices. A single-case, multiple-probe design study across three BCBAs was conducted, and findings support a functional relationship between the CoCarePD and BCBAs’ use of coaching practices.

Air pollution in urban environments has been shown to have a negative impact on air quality and human health, particularly in megacities. Over recent decades, Delhi, India, has suffered high atmospheric pollution, with significant particulate matter (PM) concentrations as a result of anthropogenic activities. Organic aerosols (OAs) are composed of thousands of different chemical species and are one of the main constituents of submicron particles. However, quantitative knowledge of OA composition, their sources and their processes in urban environments is still limited. This is important particularly in India, as Delhi is a massive, inhomogeneous conurbation, where we would expect the apportionment and concentrations to vary depending on where in Delhi the measurements/source apportionment is performed, indicating the need for multisite measurements. This study presents the first multisite analysis carried out in India over different seasons, with a focus on identifying OA sources. The measurements were taken during 2018 at two sites in Delhi, India. One site was located at the India Meteorological Department, New Delhi (ND). The other site was located at the Indira Gandhi Delhi Technical University for Women, Old Delhi (OD). Non-refractory submicron aerosol (NR-PM1) concentrations (ammonium, nitrate, sulfate, chloride and organic aerosols) of four aerosol mass spectrometers were analysed. Collocated measurements of volatile organic compounds, black carbon, NOx and CO were performed. Positive matrix factorisation (PMF) analysis was performed to separate the organic fraction, identifying a number of conventional factors: hydrocarbon-like OAs (HOAs) related to traffic emissions, biomass burning OAs (BBOAs), cooking OAs (COAs) and secondary OAs (SOAs). A composition-based estimate of PM1 is defined by combining black carbon (BC) and NR-PM1 (C-PM1= BC + NR-PM1). No significant difference was observed in C-PM1 concentrations between sites, OD (142 ± 117 µg m−3) compared to ND (123 ± 71 µg m3), from post-monsoon measurements. A wider variability was observed between seasons, where pre-monsoon and monsoon showed C-PM1 concentrations lower than 60 µg m−3. A seasonal variation in C-PM1 composition was observed; SO42- showed a high contribution over pre-monsoon and monsoon seasons, while NO3- and Cl− had a higher contribution in winter and post-monsoon. The main primary aerosol source was from traffic, which is consistent with the PMF analysis and Aethalometer model analysis. Thus, in order to reduce PM1 concentrations in Delhi through local emission controls, traffic emission control offers the greatest opportunity. PMF–aerosol mass spectrometer (AMS) mass spectra will help to improve future aerosol source apportionment studies. The information generated in this study increases our understanding of PM1 composition and OA sources in Delhi, India. Furthermore, the scientific findings provide significant information to strengthen legislation that aims to improve air quality in India.

This article reports on a simulated phishing experiment targeting 6,938 faculty and staff at George Mason University. The three-week phishing campaign employed three types of phishing exploits and examined demographic, linked workstation/network monitoring audit data, and a variety of behavioral and psychological factors measured via pre- and post-campaign surveys. While earlier research studies have reported disparate effects of gender and age, the present results suggest that these effects are not significant or are of limited strength and that other underlying factors may be more important. Specifically, significant differences in phishing susceptibility were obtained for different email contexts and based on whether individuals have been successfully phished before (these people were more likely to succumb to subsequent phishing emails in our study). Further, participants who responded to phishing exploits scored higher on impulsivity than the non-clickers. Also, participants whose survey responses indicated that they had more appropriate online “security hygiene habits,” such as checking the legitimacy of links, were less likely to be successfully phished in our campaign. Participants whose post-campaign survey responses indicated that they were suspicious of a phishing email message in our campaign were far less likely to click on the phishing link than those who were not suspicious. Similar results were obtained for judgments of pertinence of the email. Participants who indicated that they thought about the negative consequences of clicking the link were less likely to do so than participants who did not think about the negative consequences. Implications for effective training and awareness are discussed.

Volatile organic compounds (VOCs) are important precursors to the formation of ozone (O3) and secondary organic aero-sols (SOA) and can also have direct human health impacts. Generally, given the range and number of VOC species, their emissions are poorly characterised. The VOC levels in Beijing during two campaigns (APHH) were investigated using a dispersion model (NAME), and a chemical box model (AtChem2) in order to understand how chemistry and transport affect the VOC concentrations in Beijing. Emissions of VOCs in Beijing and contributions from outside Beijing were modelled using the NAME dispersion model combined with the emission inventories and were used to initialize the AtChem2 box model. The modelled concentrations of VOCs from the NAME-AtChem2 combination were then compared to the output of a chemical transport model (GEOS-Chem). The results from the emission inventories and the NAME air mass pathways suggest that industrial sources to the south of Beijing and within Beijing both in summer and winter are very important in con-trolling the VOC levels in Beijing. A number of scenarios with different nitrogen oxides to ozone ratios (NOx / O3) and hydroxyl (OH) levels were simulated to determine the changes in VOC levels. In Beijing over 80 % of VOC are emitted locally during winter, while during summer about 35 % of VOC concentrations (greater for some individual species) are transported into Beijing from the surrounding regions. Most winter scenarios are in good agreement with daily GEOS-Chem simulations, with the best agreements seen for the modelled concentrations of ethanol, benzene and propane with correlation coefficients of 0.67, 0.63 and 0.64 respectively. Furthermore, the production of formaldehyde within 24 hours air travel from Beijing was investigated, and it was determined that 90 % of formaldehyde in the winter and 83 % in the summer in Beijing is secondary, produced from oxidation of non-methane volatile organic compounds (NMVOCs). The benzene / CO and toluene / CO ratios during the campaign is very similar to the ratio derived from literature for 2014 in Beijing, however more data are needed to enable investigation of more species over longer timeframes to determine whether this ratio can be applied to predicting VOCs in Beijing. The results suggest that VOC concentrations in Beijing are driven predominantly by sources within Beijing and by local atmospheric chemistry during the winter, and by a combination of transport and chemistry during the summer. Moreover, the relationship of the NOx / VOC and O3 during winter and summer shows the need for season-specific policy measures.

Atmospheric nitrogen oxides (NO + NO 2 = NO x ) have been measured at the Cape Verde Atmospheric Observatory (CVAO) in the tropical Atlantic (16 ∘ 51 ′ N, 24 ∘ 52 ′ W) since October 2006. These measurements represent a unique time series of NO x in the background remote troposphere. Nitrogen dioxide (NO 2 ) is measured via photolytic conversion to nitric oxide (NO) by ultraviolet light-emitting diode arrays followed by chemiluminescence detection. Since the measurements began, a blue light converter (BLC) has been used for NO 2 photolysis, with a maximum spectral output of 395 nm from 2006 to 2015 and of 385 nm from 2015 onwards. The original BLC used was constructed with a Teflon-like material and appeared to cause an overestimation of NO 2 when illuminated. To avoid such interferences, a new additional photolytic converter (PLC) with a quartz photolysis cell (maximum spectral output also 385 nm) was implemented in March 2017. Once corrections are made for the NO 2 artefact from the original BLC, the two NO 2 converters are shown to give comparable NO 2 mixing ratios (BLC = 0.99 × PLC + 0.7 ppt, linear least-squares regression), giving confidence in the quantitative measurement of NO x at very low levels. Data analysis methods for the NO x measurements made at CVAO have been developed and applied to the entire time series to produce an internally consistent and high-quality long-term data set. NO has a clear diurnal pattern with a maximum mixing ratio of 2–10 ppt during the day depending on the season and ∼ 0 ppt during the night. NO 2 shows a fairly flat diurnal signal, although a small increase in daytime NO x is evident in some months. Monthly average mixing ratios of NO 2 vary between 5 and 30 ppt depending on the season. Clear seasonal trends in NO and NO 2 levels can be observed with a maximum in autumn and winter and a minimum in spring and summer.

Chronic disease management requires achievement of critical individualised targets to mitigate again long-term morbidity and premature mortality associated with diabetes mellitus. The responsibility for this lies with both the patient and health care professionals. Care plans have been introduced in many healthcare settings to provide a patient-centred approach that is both evidence-based to deliver positive clinical outcomes and allow individualised care. The Alphabet strategy (AS) for diabetes is based around such a care plan and has been evidenced to deliver high clinical standards in both well-resourced and under-resourced settings. Additional patient educational resources include special care plans for those people with diabetes undertaking fasting during Ramadan, Preconception Care, Prevention and Remission of Diabetes. The Strategy and Care Plan has facilitated evidence-based, cost-efficient multifactorial intervention with an improvement in the National Diabetes Audit targets for blood pressure, cholesterol levels and glycated haemoglobin. Many of these attainments were of the standard seen in intensively treated cohorts of key randomized controlled trials in diabetes care such as the Steno-2 and United Kingdom Prospective Diabetes Study. This is despite working in a relatively under-resourced service within the United Kingdom National Health Service. The AS for diabetes care is a useful tool to consider for planning care, education of people with diabetes and healthcare professional. During the time of the coronavirus disease 2019 pandemic the risk factors for the increased mortality observed have to be addressed aggressively. The AS has the potential to help with this aspiration.

Although the Individuals With Disabilities Education Improvement Act (IDEA) mandates parent participation in their children’s education programs, the implementation of IDEA results in parent effort beyond participation, specifically, an expectation of advocacy. To date, research on the advocacy expectation is mixed, with some parents perceiving advocacy as an obligation to ensure appropriate services for their children, whereas others argue it is unreasonable and has cultural dissonance, disadvantaging some parents. We examined parent perspectives of the advocacy expectation in special education through 19 focus groups with 127 parents of children with disabilities across four states. Findings included a nuanced understanding of the advocacy expectation, with participants reporting the importance of advocacy and some describing that advocacy was part of their social role. However, under adversarial circumstances with school personnel, participants described feeling overwhelmed because the advocacy expectation felt more difficult than it needed to be. We discuss implications for policy and practice.