Hygroscopic growth and activation of HULIS particles: experimental data and a new iterative parameterization scheme for complex aerosol particles

International audienceThe hygroscopic growth and activation of two HULIS and one Aerosol-Water-Extract sample, prepared from urban-type aerosol, were investigated. All samples were extracted from filters, redissolved in water and atomized for the investigations presented here. The hygroscopic growth measurements were done using LACIS (Leipzig Aerosol Cloud Interaction Simulator) together with a HH-TDMA (High Humidity Tandem Differential Mobility Analyzer). Hygroscopic growth was determined for relative humidities up to 99.75%. The critical diameters for activation were measured using LACIS for supersaturations between 2 and 10 per mill. All three samples showed a similar hygroscopic growth behaviour, and the two HULIS samples also were similar in their activation behavior, while the Aerosol-Water-Extract turned out to be more CCN active than the HULIS samples. The experimental data was used to derive parameterizations for the hygroscopic growth and activation of HULIS particles. The concept of ?ion (Wex et al., 2007a) and the Szyszkowski-equation (Szyszkowski, 1908; Facchini et al., 1999) were used for parameterizing the Raoult and the Kelvin (surface tension) terms of the Köhler equation, respectively. This concept proved to be very successful for the HULIS samples in the saturation range from relative humidities larger than 98% up to activation. However it failed for the Aerosol-Water extract

In Solidarity

This edition of Next Page is a departure from our usual question and answer format with a featured campus reader. Instead, we asked speakers who participated in the College’s recent Student Solidarity Rally (March 1, 2017) to recommend readings that might further our understanding of the topics on which they spoke

Hygroscopic growth and activation of HULIS particles: Experimental data and a new iterative parameterization scheme for complex aerosol particles

The hygroscopic growth and activation of two HULIS (HUmic LIke Substance) and one Aerosol-Water-Extract sample, prepared from urban-type aerosol, were investigated. All samples were extracted from filters, redissolved in water and atomized for the investigations presented here. The hygroscopic growth measurements were done using LACIS (Leipzig Aerosol Cloud Interaction Simulator) together with a HH-TDMA (High Humidity Tandem Differential Mobility Analyzer). Hygroscopic growth was determined for relative humidities (RHs) up to 99.75%. The critical diameters for activation were measured for supersaturations between 0.2 and 1%. All three samples showed a similar hygroscopic growth behavior, and the two HULIS samples also were similar in their activation behavior, while the Aerosol-Water-Extract turned out to be more CCN active than the HULIS samples. The experimental data was used to derive parameterizations for the hygroscopic growth and activation of HULIS particles. The concept of ρion (Wex et al., 2007a) and the Szyszkowski-equation (Szyszkowski, 1908; Facchini, 1999) were used for parameterizing the Raoult and the Kelvin (surface tension) terms of the Köhler equation, respectively. This concept proved to be very successful for the HULIS samples in the saturation range from RHs larger than 98% up to activation. It was also shown to work well with data on HULIS taken from literature. Here, different atmospheric life-times and/or different sources for the different samples showed up in different coefficients for the parameterization. However, the parameterization did not work out well for the Aerosol-Water-Extract

Parent-reported outcomes in young children with disorders/differences of sex development

Background: There is a paucity of tools that can be used in routine clinical practice to assess the psychosocial impact of Disorders/Differences of Sex Development (DSD) on parents and children. Objective: To evaluate the use of short Parent Self-Report and Parent Proxy-Report questionnaires that can be used in the outpatient setting. Methods: Previously validated DSD-specific and generic items were combined to develop a Parent Self-Report questionnaire and a Parent Proxy-Report questionnaire for children under 7 years. Of 111 children approached at one tertiary paediatric hospital, the parents of 95 children (86%) with DSD or other Endocrine conditions completed these questionnaires. Results: Questionnaires took under 10 min to complete and were found to be easy to understand. Compared to reference, fathers of children with DSD reported less stress associated with Clinic Visits (p = 0.02) and managing their child’s Medication (p = 0.04). However, parents of children with either DSD or other Endocrine conditions reported more symptoms of Depression (p = 0.03). Mothers of children with DSD reported greater Future Concerns in relation to their child’s condition (median SDS − 0.28; range − 2.14, 1.73) than mothers of children with other Endocrine conditions (SDS 1.17; − 2.00, 1.73) (p = 0.02). Similarly, fathers of children with DSD expressed greater Future Concerns (median SDS -1.60; − 4.21, 1.00) than fathers of children with other Endocrine conditions (SDS 0.48; − 2.13, 1.52) (p = 0.04). Conclusion: DSD was associated with greater parental concerns over the child’s future than other Endocrine conditions. Brief parent-report tools in DSD can be routinely used in the outpatient setting to assess and monitor parent and patient needs

Prospects for habitat management to suppress vegetable pests in Australia

Abstract Habitat management is an ecologically based approach to suppress pest densities, utilising properties of non-crop vegetation to improve the impact of natural enemies or to directly affect pest behaviour. Research in this approach has escalated dramatically this century, extending to uptake in some crops, but adoption in Australia has been lower than overseas. Here, we address the need of the Australian vegetable sector to reduce reliance on insecticides by assessing the scope for habitat management in brassica (Brassicaceae), lettuce (Lactuca sativa) (Asteraceae), capsicum (Capsicum annuum) (Solanaceae), carrot (Daucus carota) (Apiaceae), French bean (Phaseolus vulgaris) (Fabaceae) and sweetcorn (Zea mays) (Poaceae) crops. Each crop is of major economic importance, and together, they represent contrasting botanical families and production systems that are associated with different arthropod complexes. We review studies of habitat management that are based on provision of shelter, nectar, alternative prey or pollen for natural enemies (top-down effects) or changing pest behaviour (bottom-up effects) through intercropping or trap crops. The likely utility of these approaches under Australian conditions is assessed, and recommendations are made to promote adoption and for adaptive research. Nectar- and pollen-providing plants, such as alyssum (Lobularia maritima) (Brassicaceae), offer strong potential to promote natural enemies in multiple crops whilst trap crops, especially yellow rocket (Barbarea vulgaris) (Brassicaceae), have more targeted utility against diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae), the most serious pest of brassicas. Opportunities for intercrops and banker plant species are also identified. Our recommendations serve as a platform for researchers and for farmer-led studies to help realise the full potential of habitat management approaches in Australian vegetable production systems

Psychotic-like experiences among university female students in Qatar: A qualitative-phenomenological study

Background and aims: Psychotic-like experiences (PLEs) are hallucinatory or delusional experiences that fall below the threshold of a diagnosable psychotic disorder. Although PLEs are common across the spectrum of psychiatric disorders, they also have been commonly reported in the general population. In this study, we aimed to describe the types of PLEs experienced by university students in Qatar. Furthermore, we aimed to examine how students frame, explain, and deal with these experiences as well as understand how culture and religion may shape the way students attribute and respond to these experiences. Method: This study used a qualitative phenomenological approach. For collecting the data, we conducted semi-structured interviews using the Questionnaire for Psychotic Experiences (QPE). The QPE is a valid and reliable tool to assess the phenomenology of psychotic-like experiences. The questionnaire was translated into Arabic and tested and validated in Qatar (a fast-developing Muslim country in the Arabian Peninsula). We conducted interviews in Arabic with 12 undergraduate female students at Qatar University (the only national university in Qatar). The interviewees were of different Arab nationalities. Interviews were transcribed verbatim and two authors conducted the content-thematic analysis separately, as a strategy to validate the findings. The study was part of a larger nationally funded project that was approved by the Qatar University Institutional Review Board. The approvals were granted before any interview was conducted. Results: The PLEs were prevalent in our non-clinical sample. The content-thematic analysis revealed the following main themes about these experiences: type, impact on daily function, frequency, immediate reaction, attribution style, assumptions about the root cause of these experiences, other associations, and religious links to experiences. The results also highlighted that religion and culture play a role in shaping the types of hallucinations and some delusions. Conclusion: Our findings support the importance of culture and religion in relation to the types and explanations that students provided when describing PLEs. Notably, it was common among those who reported having these experiences to normalize and link PLEs to real-life events. This may be a defense mechanism to protect the self against the stigma of mental illness and from being labeled as “abnormal”.This research was supported by the National Priorities Research Program award (NPRP-11S- 0119-180341) awarded to PW, SK, IS, and AY from the Qatar National Research Fund (a member of the Qatar Foundation)

Insights into the sources of ultrafine particle numbers at six European urban sites obtained by investigating COVID-19 lockdowns

Lockdown restrictions in response to the COVID-19 pandemic led to the curtailment of many activities and reduced emissions of primary air pollutants. Here, we applied positive matrix factorisation to particle size distribution (PSD) data from six monitoring sites (three urban background and three roadside) between four European cities (Helsinki, Leipzig, Budapest, and London) to evaluate how particle number concentrations (PNCs) and their sources changed during the respective 2020 lockdown periods compared to the reference years 2014-2019. A number of common factors were resolved between sites, including nucleation, road traffic semi-volatile fraction (road trafficsvf), road traffic solid fraction (road trafficsf), diffuse urban (wood smoke + aged traffic), ozone-Associated secondary aerosol (O3-associated SA), and secondary inorganic aerosol (SIA). Nucleation, road traffic, and diffuse urban factors were the largest contributors to mean PNCs during the reference years and respective lockdown periods. However, SIA factors were the largest contributors to particle mass concentrations, irrespective of environment type. Total mean PNCs were lower at two of the urban-background and all roadside sites during lockdown. The response of nucleation and road trafficsvf factors to lockdown restrictions was highly variable, although road trafficsf factors were consistently lower at roadside sites. The responses of diffuse urban factors were largely consistent and were mostly lower at urban-background sites. Secondary aerosols (O3-Associated SA and SIA) exhibited extensive reductions in their mean PNCs at all sites. These variegated responses to lockdowns across Europe point to a complex network of sources and aerosol sinks contributing to PSDs.</p

Omiganan Enhances Imiquimod-Induced Inflammatory Responses in Skin of Healthy Volunteers

Omiganan (OMN; a synthetic cationic peptide) and imiquimod (IMQ; a TLR7 agonist) have synergistic effects on interferon responses in vitro. The objective of this study was to translate this to a human model for proof-of-concept, and to explore the potential of OMN add-on treatment for viral skin diseases. Sixteen healthy volunteers received topical IMQ, OMN, or a combination of both for up to 4 days on tape-stripped skin. Skin inflammation was quantified by laser speckle contrast imaging and 2D photography, and molecular and cellular responses were analyzed in biopsies. IMQ treatment induced an inflammatory response of the skin. Co-treatment with OMN enhanced this inflammatory response to IMQ, with increases in perfusion (+17.1%; 95% confidence interval (CI) 5.6%–30%; P < 0.01) and erythema (+1.5; 95% CI 0.25%–2.83; P = 0.02). Interferon regulatory factor-driven and NFκB-driven responses following TLR7 stimulation were enhanced by OMN (increases in IL-6, IL-10, MXA, and IFNɣ), and more immune cell infiltration was observed (in particular CD4+, CD8+, and CD14+ cells). These findings are in line with the earlier mechanistic in vitro data, and support evaluation of imiquimod/OMN combination therapy in human papillomavirus-induced skin diseases

Recipient screening in IVF: First data from women undergoing anonymous oocyte donation in Dublin

BACKGROUND: Guidelines for safe gamete donation have emphasised donor screening, although none exist specifically for testing oocyte recipients. Pre-treatment assessment of anonymous donor oocyte IVF treatment in Ireland must comply with the European Union Tissues and Cells Directive (Directive 2004/23/EC). To determine the effectiveness of this Directive when applied to anonymous oocyte recipients in IVF, we reviewed data derived from selected screening tests performed in this clinical setting. METHODS: Data from tests conducted at baseline for all women enrolling as recipients (n = 225) in the anonymous oocyte donor IVF programme at an urban IVF referral centre during a 24-month period were analysed. Patient age at programme entry and clinical pregnancy rate were also tabulated. All recipients had at least one prior negative test for HIV, Hepatitis B/C, chlamydia, gonorrhoea and syphilis performed by her GP or other primary care provider before reproductive endocrinology consultation. RESULTS: Mean (±SD) age for donor egg IVF recipients was 40.7 ± 4.2 yrs. No baseline positive chlamydia, gonorrhoea or syphilis screening results were identified among recipients for anonymous oocyte donation IVF during the assessment interval. Mean pregnancy rate (per embryo transfer) in this group was 50.5%. CONCLUSION: When tests for HIV, Hepatitis B/C, chlamydia, gonorrhoea and syphilis already have been confirmed to be negative before starting the anonymous donor oocyte IVF sequence, additional (repeat) testing on the recipient contributes no new clinical information that would influence treatment in this setting. Patient safety does not appear to be enhanced by application of Directive 2004/23/EC to recipients of anonymous donor oocyte IVF treatment. Given the absence of evidence to quantify risk, this practice is difficult to justify when applied to this low-risk population