Thermal Desorption Metastable Atom Bombardment Ionization Aerosol Mass Spectrometer

A metastable atom bombardment (MAB) ionization source has been coupled to an existing thermal desorption aerosol mass spectrometer. The design allows real-time alternation between MAB and electron ionization (EI). A jet of metastable species produced in a DC discharge is directed at the ionization volume of the mass spectrometer, where Penning ionization is thought to be the dominant mechanism. Performance is characterized in experiments with oleic acid particles. By changing discharge gases between N2, Kr, and Ar, the excited state energy of the metastable species can be adjusted in the range 8.5-11.7eV. For vaporization at 180oC, all gases yield significantly less fragmentation than EI, which could improve results of factor analysis. Fragmentation increases with vaporization temperature, but generated fragments have higher average mass than those produced by EI. Analyte signal levels are 0.1% and 0.006% of equivalent analysis with EI when using Ar* and Kr*, respectively. These sensitivities are not practical for ambient studies, but are sufficient for source measurements, as demonstrated with direct measurements of biomass burning emissions. The measured Ar* flux of 3.6 x 1013sr-1s-1 is ~30 times lower than the best literature values for similar metastable beam sources, suggesting that sensitivity can be increased by source design improvements

Hygroscopic Optical Growth of Atmospherically Relevant Mixed Particles

The direct interaction of ambient atmospheric particles with solar radiation affects Earth's climate and local visibility. Light extinction by particles in the atmosphere is strongly dependent on particle size, chemical composition, hygroscopic growth properties and particle mixing state. Changes in relative humidity can influence particle extinction because hygroscopic growth causes the particles to increase in size. Laboratory quantification of the optical growth of various particle compositions is needed for inclusion in radiative transfer models. While the optical growth of pure particles is well understood, less is known about mixed particles. Atmospheric aerosols are typically 50-80% organic, but also contain sulfates. This thesis describes laboratory investigations into the role of organics on the optical hygroscopic growth of ammonium sulfate (AS). The influence of an organic 1,2,6-hexanetriol coating on an ammonium sulfate particle was first studied. The particle optical growth factor, fRHext, was measured using cavity ring-down aerosol extinction spectroscopy at 532 nm. The particles were composed of pure ammonium sulfate, pure 1,2,6-hexanetriol, and mixed particles containing a wet or dry ammonium sulfate core and 1,2,6-hexanetriol coating. Dry, coated particles were generated by atomization followed by drying. Wet, coated particles were formed via liquid-liquid phase separation (LLPS). LLPS was achieved by deliquescing the mixed particles, and then the particles were dried to a relative humidity (RH) between the phase separation RH and the efflorescence RH. For the LLPS particles, the fRHext at each RH was found to be between the fRHext of ammonium sulfate and 1,2,6-hexanetriol. In contrast, for the mixed dry, coated particles, the fRHext was the same as 1,2,6-hexanetriol particles. This work shows that at room temperature, the water uptake properties of AS coated with 1,2,6-hexanetriol are largely dictated by the phase of the AS. Thus, the total water uptake depends on the RH history of the particle and the resulting phase of AS. The influence of adding semi-solid, glassy particles to AS particles on the particle optical growth was then studied. Particles were composed of ammonium sulfate (AS), 1,2,6-hexanetriol, sucrose, raffinose, and mixed particles containing AS and either sucrose or raffinose. Both sucrose and raffinose were used because they can be semi-solid or glassy at room temperature. For the pure 1,2,6-hexanetriol, sucrose, and raffinose, the particles optical growth begins to occur around an RH between 34 and 40%. The liquid 1,2,6-hexanetriol exhibits similar water uptake behavior as the glassy sucrose and raffinose. Therefore, pure glassy aerosols may be treated similar to liquids is climate change models. For the mixed AS and sucrose or raffinose particles, the component weight % significantly affects the RH where water uptake is observed. When particles contain more AS than organic, it acts similar to a pure AS particle. The AS in the mixture is crystalline, and the particle doesn't take up much water until it deliquesces. When the particle contains more organic, it acts like a liquid particle and has slow continuous water uptake. This significantly simplifies the addition of mixed glassy aerosols in climate change models

Understanding the patient journey: a mechanism to reduce staff burnout?

No abstract available

Understanding the patient journey: a mechanism to reduce staff burnout?

No abstract available

Characterization of COVID-19 Mitigation Measures Among Workers from May 2020-June 2021

Objectives: To determine the relationship between early adherence to COVID-19 mitigation measures (before vaccine availability) and later vaccination status (after vaccines were widely available) in the Southwest Indiana workforce population. Design: Retrospective analysis of existing longitudinal cohort from two surveys: a COVID-19 prevalence survey in May 2020 and a follow up survey in June 2021. Setting: This study focused on secondary analysis of existing data from two surveys of the same Southwest Indiana workforce population, spanning manufacturing, finance, healthcare, and service industries. Participants: The analysis included participants who completed the 2020 survey (845), 2021 survey (492), or both (343). Main Outcome Measures: Relationship of adherence to early mitigation measures on vaccine adoption. We also examined differences in demographic characteristics including age, rurality (rural, rural/mixed, or urban county based on zip code of residence), education level, gender, and workplace environment. Results: Significant differences in age (p=0.02) and education (p=0.01), but not rurality, were observed between the vaccinated and unvaccinated groups. Furthermore, comparison of vaccinated and unvaccinated groups found significantly different responses to the degree of self-reported mitigation practices in early 2020. Conclusions: Consistent with previous studies, we found that demographic characteristics such as age and education may influence vaccination status. Furthermore, our data suggest an association between willingness to practice mitigation measures at the beginning of the pandemic and willingness to receive the COVID-19 vaccine. 

Some Middle School Students Want Behavior Commitment Devices (but Take-Up Does Not Affect Their Behavior)

Commitment devices impose costs on one's future self for failing to follow through on one's intentions, offer no additional benefit to one's future self for following through on the intention, and people voluntarily enroll in them. Enrollment in commitment devices reflects self-awareness that one may lack sufficient self-control to fulfill one's intentions. There is little experimental research on whether school-age children possess the self-awareness necessary to enroll in a commitment device, despite evidence that children and young adolescents have many positive intentions that they fail to live up to, such as demonstrating improved school conduct or eating healthier. We report the first field experiment examining the demand for, and impact of, commitment devices among middle school students. We offered students a commitment device that imposed future costs for failing to improve in-school conduct. When presented with the opportunity to actively opt-in (default not enrolled), over one-third of students elected to enroll. When presented with the opportunity to actively opt-out (default enrolled), more than half elected to remain enrolled, showing that changing default options can increase commitment device enrollment. Despite demand for the self-control strategy, taking-up the commitment device did not affect student behavior. These findings have implications for youth-based behavioral interventions broadly, as well as those focused on eating behaviors

Software Citation Implementation Challenges

The main output of the FORCE11 Software Citation working group (https://www.force11.org/group/software-citation-working-group) was a paper on software citation principles (https://doi.org/10.7717/peerj-cs.86) published in September 2016. This paper laid out a set of six high-level principles for software citation (importance, credit and attribution, unique identification, persistence, accessibility, and specificity) and discussed how they could be used to implement software citation in the scholarly community. In a series of talks and other activities, we have promoted software citation using these increasingly accepted principles. At the time the initial paper was published, we also provided guidance and examples on how to make software citable, though we now realize there are unresolved problems with that guidance. The purpose of this document is to provide an explanation of current issues impacting scholarly attribution of research software, organize updated implementation guidance, and identify where best practices and solutions are still needed

Rebuild the Academy: Supporting academic mothers during COVID-19 and beyond

The issues facing academic mothers have been discussed for decades. Coronavirus Disease 2019 (COVID-19) is further exposing these inequalities as womxn scientists who are parenting while also engaging in a combination of academic related duties are falling behind. These inequities can be solved by investing strategically in solutions. Here we describe strategies that would ensure a more equitable academy for working mothers now and in the future. While the data are clear that mothers are being disproportionately impacted by COVID-19, many groups could benefit from these strategies. Rather than rebuilding what we once knew, let us be the architects of a new world

Software Citation Checklist for Developers

This document provides a minimal, generic checklist that developers of software (either open or closed source) used in research can use to ensure they are following good practice around software citation. This will help developers get credit for the software they create, and improve transparency, reproducibility, and reuse

Nutrition and frailty:Opportunities for prevention and treatment

Frailty is a syndrome of growing importance given the global ageing population. While frailty is a multifactorial process, poor nutritional status is considered a key contributor to its pathophysiology. As nutrition is a modifiable risk factor for frailty, strategies to prevent and treat frailty should consider dietary change. Observational evidence linking nutrition with frailty appears most robust for dietary quality: for example, dietary patterns such as the Mediterranean diet appear to be protective. In addition, research on specific foods, such as a higher consumption of fruit and vegetables and lower consumption of ultra-processed foods are consistent, with healthier profiles linked to lower frailty risk. Few dietary intervention studies have been conducted to date, although a growing number of trials that combine supplementation with exercise training suggest a multi-domain approach may be more effective. This review is based on an interdisciplinary workshop, held in November 2020, and synthesises current understanding of dietary influences on frailty, focusing on opportunities for prevention and treatment. Longer term prospective studies and well-designed trials are needed to determine the causal effects of nutrition on frailty risk and progression and how dietary change can be used to prevent and/or treat frailty in the future