Probing The Unimolecular Decay Of Atmospherically Important Criegee Intermediates

Ozonolysis of alkenes is an important source of hydroxyl (OH) radicals, key oxidants in the Earth’s troposphere. Alkene ozonolysis proceeds via carbonyl oxide species known as Criegee intermediates. Infrared (IR) action spectroscopy is used to study OH production from jet-cooled, stabilized Criegee intermediates. IR activation drives the rate-limiting 1,4 H-atom transfer from a syn-alkyl substituent to the terminal oxygen of the carbonyl oxide group, followed by rapid unimolecular decay to OH, which is detected by ultraviolet (UV) laser-induced fluorescence (LIF). IR action spectra provide spectral fingerprints of the Criegee intermediates. OH appearance rates are measured following IR activation by varying the IR-UV time delay. This technique is applied to two prototypical Criegee intermediates, syn-CH3CHOO and (CH3)2COO, in three different energy regimes, including at energies significantly below the calculated transition state (TS) barrier, indicating the importance of quantum mechanical tunneling in the H-atom transfer reaction. The role of tunneling is further confirmed by a significant observed kinetic isotope effect for the D-atom transfer reaction of syn-CD3CHOO. The IR action spectroscopy technique is also extended to more complex Criegee intermediates. Methyl vinyl ketone oxide (MVK-oxide) is an unsaturated four-carbon Criegee intermediate formed from the ozonolysis of isoprene, the most abundant non-methane volatile organic compound in the atmosphere. MVK-oxide was generated via a novel synthetic method and identified by its IR action spectrum. OH appearance rate measurements validate the calculated TS barrier for the H-atom shift reaction, and provide insight into an alternative unimolecular decay mechanism. The methyl-ethyl substituted Criegee intermediate (MECI) is a saturated four-carbon Criegee intermediate and is unique among Criegee intermediates studied by IR action spectroscopy because multiple conformational forms can undergo H-atom transfer to OH. Comparisons among the Criegee intermediates studied provides insight into substituent effects on unimolecular decay. The experimental OH appearance rates across many systems are in good agreement with statistical RRKM rate calculations incorporating tunneling, validating the unimolecular decay mechanism. Finally, UV LIF is used to detect vinoxy radicals, a coproduct in the H-atom transfer reaction. LIF detection of vinoxy radicals may be a probe for alternative unimolecular chemistry of vinyl-substituted Criegee intermediates from isoprene ozonolysis

Low-Dimensional Reality-Based Algebras

In this paper we introduce the definition of a reality-based algebra (RBA) as well as a subclass of reality-based algebras, table algebras. Using sesquilinear forms, we prove that a reality-based algebra is semisimple. We look at a specific reality-based algebra of dimension 5 and provide formulas for the structure constants of this algebra. We determine by looking at these structure constants and setting conditions on specific structural components when this particular reality-based algebra is a table algebra. In fact, this will be a noncommutative table algebra of dimension 5

Jet-Cooled Spectroscopic Characterization of Anethole (methoxy-4-(prop-1-enyl)benzene), a Natual Styrene Derivative

The molecular structure of anethole (methoxy-4-(prop-l-enyl)benzene), was investigated using Jet-Cooled UV spectroscopy. A laser-induced fluorescence spectrum was obtained of the S₁-S₀ transition. Two 0⁰₀ transitions were observed in the LIF spectrum, separated by 69 cm⁻¹, and were assigned to the syn and anti conformers of anethole. Single vibronic level fluorescence spectra were obtained for both of the origin transitions. Bands of the S|VLF spectrum of each conformer were assigned by comparison with theoretical calculations at the DFT/B3LYP, 6-311G++(d,p) level of theory, as well as experimental information from similar molecules. In order to assign the LIF spectrum further, SVLF spectra were obtained of many of the LIF transitions, and assigned where possible. SVLF transitions of particular importance are the 63⁰₂ and the 39⁰₁ which appear reliably in almost all SVLF spectra, but at slightly different frequencies for each conformer, allowing the assignment of SVLF spectra to a specific conformation of anethole. LIF and SVLF data indicated the possibility of water-anethole van der Waals clusters, which were confirmed by adding water to the jet. Additionally, we performed potential energy scans of the vinyl and methoxy rotations of anethole, and fit these scans in order to determine parameters for anharmonicity and the barrier to rotation. By comparing to experimental fits in the literature, we determined that MP2 calculations predicted the barrier to rotation best, but HF calculations did a better job of predicting the anharmonicity. Opportunities for future work include the modeling of the potential using experimental data, further investigation of anethole-water clusters, finishing the assignment of the LIF and SVLF, and possibly investigating the spectroscopy of cis-anethole

Searching for Communities in Bipartite Networks

Bipartite networks are a useful tool for representing and investigating interaction networks. We consider methods for identifying communities in bipartite networks. Intuitive notions of network community groups are made explicit using Newman's modularity measure. A specialized version of the modularity, adapted to be appropriate for bipartite networks, is presented; a corresponding algorithm is described for identifying community groups through maximizing this measure. The algorithm is applied to networks derived from the EU Framework Programs on Research and Technological Development. Community groups identified are compared using information-theoretic methods.Comment: 12 pages, 4 figures, to appear in "Proceedings of the 5th Jagna International Workshop: Stochastic and Quantum Dynamics of Biomolecular Systems," C. C. Bernido and M. V. Carpio-Bernido, editors. A version with full-quality figures and larger file size is available at http://ccm.uma.pt/publications/Barber-Faria-Streit-Strogan-2008.pd

Young people's beliefs about the health effects of different alcoholic beverages : an exploratory comparison of the UK and France

Different kinds of alcoholic drink have different connotations for drinkers in terms of their potential to produce intoxication and their effects on health. These connotations are likely to be important influences on drinking behaviour. This mixed methods study examined how young people (18 to 24 years old) in two countries with different drinking cultures (France and the UK) perceive the costs and benefits of consuming particular kinds of alcoholic beverage, specifically contrasting beers (blonde and dark), wines (red and white) and spirits (clear and dark). More broadly, the project evaluated young peoples beliefs about the different beverage types, and the factors that influence their choices of beverage, including, peer influence, beliefs about drink-specific effects and how different kinds of drink affect body weight. A pilot study of online drinking diaries was conducted to establish drinking trends among young adults in the two countries. A number of key difference were found between the two countries which informed areas of discussion in the focus groups, including beverage preferences, the difference in levels of preloading and mixing drinks, as well as the relationship between alcohol and food. The qualitative part consisted of sixteen structured focus groups (8 in each country), which examined participants’ understanding and beliefs about the health consequences of consuming different kinds of alcoholic beverage. They also explored how different drinks are related to drinking styles. In both countries, participants highlighted ‘getting drunk’ as a reason for drinking, and they adopted similar justifications for their drinking behaviours. UK participants tended to view all drinks (except wine) as equally problematic for health, whereas French participants had more diverse beliefs about the health effects of different beverages. The quantitative phase consisted of a large survey distributed across the two countries (UK= 555 participants and France= 401), which looked further into people’s health beliefs about different beverage types. The notion that wine is healthier than other beverages was widely held in both countries, but was stronger in France than the UK and it had different determinants in the two countries. Also, in France, spirits were identified as particularly problematic for health, much more so than in the UK. In the UK, apart from wine, all beverages were considered to have a similar potential for causing health problems. Liver damage was identified as a key problem linked to chronic alcohol consumption; in France, it was most strongly associated with drinking dark spirits, whereas in the UK it was not linked to any particular beverage type(s). In both countries, the acute effects on health were more salient than the chronic effects, and the primary concern relating to long-term consumption was addiction rather than damage to physical health. Lastly, 14 semi-structured interviews were conducted in the two countries (7 in each country) exploring the impacts of public information, media reports and peer influence on beliefs about different beverage types. Across the two countries the participants believed that there was a lack of information about the long-term health effects of alcohol, and expressed a lack of trust in the media (i.e. newspapers and television advertising). They believed that information should be more accessible through the internet, i.e. social media sites, and they also suggested the use of images to illustrate the major health impacts of alcohol consumption. To conclude: drinking practices and views about alcohol’s health effects appear to be converging across the two countries. Participants showed a limited understanding of (and concern about) long-term health problems associated with different drinks, and their views were confounded with stereotypes about typical consumers and beliefs about the “naturalness” or “authenticity” of different drink types

Palliative care needs of people and/or their families with serious and/or chronic health conditions in low- or middle-income country (LMIC) humanitarian settings-a systematic scoping review protocol

BACKGROUND: Palliative care in low- or middle-income country (LMIC) humanitarian settings is a new area, experiencing a degree of increased momentum over recent years. The review contributes to this growing body of knowledge, in addition to identifying gaps for future research. The overall aim is to systematically explore the evidence on palliative care needs of patients and/or their families in LMIC humanitarian settings.METHODS: Arksey and O'Malley's (Int J Soc Res Methodol. 8:19-32, 2005) scoping review framework forms the basis of the study design, following further guidance from Levac et al. (Implement Sci 5:1-9, 2010), the Joanna Briggs Institute (JBI) Peters et al. (JBI Reviewer's Manual JBI: 406-452, 2020), and the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) from Tricco et al. (Ann Intern Med 169:467-73, 2018). This incorporates a five-step approach and the population, concept, and context (PCC) framework. Using already identified key words/terms, searches for both published research and gray literature from January 2012 to October 2022 will be undertaken using databases (likely to include Cumulative Index of Nursing and Allied Health (CINAHL), MEDLINE, Embase, Global Health, Scopus, Applied Social Science Index and Abstracts (ASSIA), Web of Science, Policy Commons, JSTOR, Library Network International Monetary Fund and World Bank, Google Advanced Search, and Google Scholar) in addition to selected pre-print sites and websites. Data selection will be undertaken based on the inclusion and exclusion criteria and will be reviewed at each stage by two reviewers, with a third to resolve any differences. Extracted data will be charted in a table. Ethical approval is not required for this review.DISCUSSION: Findings will be presented in tables and diagrams/charts, followed by a narrative description. The review will run from late October 2022 to early 2023. This is the first systematic scoping review specifically exploring the palliative care needs of patients and/or their family, in LMIC humanitarian settings. The paper from the review findings will be submitted for publication in 2023.</p

Simulation of Blood Flow and Nanoparticle Transport in a Stenosed Carotid Bifurcation and Pseudo-Arteriole

Numerical simulation of flow through a realistic bifurcated carotid artery geometry with a stenosis has been conducted for comparison to experimental measurements. The behaviour of simplified therapeutic nanoparticles in relatively low concentration was observed using a discrete particle approach. The role of size (diameters from 500 nm to 50 nm) in determining particle residence time and the potential for both desirable and undesirable wall interactions was investigated. It was found that mean particle residence time reduced with decreasing particle diameter, and the percentage of particles experiencing one or more wall interactions increased simultaneously. Further simulations were conducted on a scaled-down version of the geometry which approximated the size and flow conditions of an arteriole with capillary branches, and in this instance the mean residence time increased with decreasing particle diameter, owing largely to the greater influence of Brownian motion. 33% of all 50 nm particles were involved in wall interactions, indicating that smaller particles would have a greater ability to target, for instance, cancerous tumours in such regions

The effectiveness of Advance Care Planning (ACP) training for care home staff: an updated systematic review

Context: Population ageing and projections that more people will die in care homes demand that care home staff are prepared for advance care planning (ACP). This is an update of a prior review, published in 2021, of ACP education interventions for healthcare professionals in care homes. Objective: We sought to address the questions: (1) What ACP education interventions exist for care home staff? and (2) How effective are these interventions? Method: The review adheres to PRISMA; PROSPERO (ID: CRD42022337865). Original research evaluating ACP education for care home staff, reporting any measurable outcome of effectiveness, was included. Extensive literature searches were performed from March 2018 to June 2022. The results were reported by narrative synthesis. Findings: We identified 10 studies (310 care homes), from the UK, Belgium, Norway and Canada. Major sources of heterogeneity between studies include intervention design, target population and outcome measure. More recent interventions target the wider multi-disciplinary team. There is a trend towards the adoption of more resident/family and staff-related outcomes. There was insufficient evidence to draw conclusions about the effectiveness of ACP education interventions. Limitations: Heterogeneity of the primary studies did not allow for meta-analysis. Implications: There is still insufficient data to determine the effectiveness of ACP education interventions for care home staff. Future researchers should aim to agree on outcomes that are specific to ACP education interventions for care home staff and develop standardised, validated outcome measures. Study design should consider an intervention’s ‘theory of change’ when considering outcomes