Fully anharmonic infrared cascade spectra of polycyclic aromatic hydrocarbons

The infrared (IR) emission of polycyclic aromatic hydrocarbons (PAHs) permeates our universe; astronomers have detected the IR signatures of PAHs around many interstellar objects. The IR emission of interstellar PAHs differs from their emission as seen under conditions on Earth, as they emit through a collisionless cascade down through their excited vibrational states from high internal energies. The difficulty in reproducing interstellar conditions in the laboratory results in a reliance on theoretical techniques. However, the size and complexity of PAHs requires careful consideration when producing the theoretical spectra. In this work we outline the theoretical methods necessary to lead to a fully theoretical IR cascade spectra of PAHs including: an anharmonic second order vibrational perturbation theory (VPT2) treatment; the inclusion of Fermi resonances through polyads; and the calculation of anharmonic temperature band shifts and broadenings (including resonances) through a Wang--Landau approach. We also suggest a simplified scheme to calculate vibrational emission spectra that retains the essential characteristics of the full IR cascade treatment and can directly transform low temperature absorption spectra in IR cascade spectra. Additionally we show that past astronomical models were in error in assuming a 15 cm$^{-1}$ correction was needed to account for anharmonic emission effects

Spark Plasma Sintering as a powder processing route for pre-alloyed Sm2(Co, Fe, Cu, Zr)17 permanent magnets

The ’rare earth crisis’ that occurred in 2011 ignited research into mitigating and replacing the dependence on these elements in Rare Earth Permanent Magnets (REPM) and their applications. It is the former that this body of work is based upon. A method of increasing the bulk resistivity of a REPM, Sm(Co, Fe, Cu, Zr)8.2 (henceforth referred to as Sm2(Co, Fe, Cu, Zr)17), through the addition of an electrically insulating material, CaF2, to form a rare earth composite permanent magnet is studied. The aim of increasing the bulk resistivity is to minimise the irreversible demagnetisation and performance losses that occur within REPMs due to circulating eddy currents during operation of high frequency applications, such as electric motors and drives. The project utilises an emerging sintering technology platform, Spark Plasma Sintering (SPS), to rapidly consolidate powders. The processing methodology for Sm2(Co, Fe, Cu, Zr)17 powders by the SPS technique has therefore been studied with the optimal processing parameters found for producing full dense specimens for study: 1050°C to 1100°C hold temperature, 100°C= min to 200°C= min heating rate, 51MPa hold pressure and 5 minute hold time. Sm2(Co, Fe, Cu, Zr)17 permanent magnets require a characteristic multi-stage heat treatment to precipitate a cellular nanostructure which enhances the coercivity of the permanent magnets. The optimal heat treatment for the full density SPS processed Sm2(Co, Fe, Cu, Zr)17 magnets has also been studied, with the following achieving the largest coercivities and energy products: 1. Homogenisation - 1170°C for 2 hours in an argon atmosphere. Cooled slowly in air to room temperature. 2. Ageing - 850°C for 8 hours (for largest coercivity) or 16 hours (for largest (BH)max) in argon atmosphere. 3. Slow cool (1°C=min) from 850°C to 400°C in argon atmosphere. Quench in oil to room temperature. This established processing route was then used to prototype isotropic Sm2(Co, Fe, Cu, Zr)17 and CaF2 composite magnets and study the effect of the electrically insulating phase on the microstructure, and material and magnetic properties before and after heat treatment

“I’m Not Gonna Pull the Rug out from under You”: Patient-Provider Communication about Opioid Tapering

In response to increases in harms associated with prescription opioids, opioid prescribing has come under greater scrutiny, leading many healthcare organizations and providers to consider or mandate opioid dose reductions (tapering) for patients with chronic pain. Communicating about tapering can be difficult, particularly for patients on long-term opioids who perceive benefits and are using their medications as prescribed. Given the importance of effective patient-provider communication for pain management and recent health system-level initiatives and provider practices to taper opioids, this study used qualitative methods to understand communication processes related to opioid tapering, to identify best practices and opportunities for improvement. Up to 3 clinic visits per patient were audio-recorded, and individual interviews were conducted with patients and their providers. Four major themes emerged: 1) Explaining—Patients needed to understand individualized reasons for tapering, beyond general, population-level concerns such as addiction potential; 2) Negotiating—Patients needed to have input, even if it was simply the rate of tapering; 3) Managing difficult conversations—When patients and providers did not reach a shared understanding, difficulties and misunderstandings arose; 4) Non-abandonment—Patients needed to know that their providers would not abandon them throughout the tapering process

The Capacity of Cognitive Control Estimated from a Perceptual Decision Making Task

Cognitive control refers to the processes that permit selection and prioritization of information processing in different cognitive domains to reach the capacity-limited conscious mind. Although previous studies have suggested that the capacity of cognitive control itself is limited, a direct quantification of this capacity has not been attempted. In this behavioral study, we manipulated the information rate of cognitive control by parametrically varying both the uncertainty of stimul measured as information entropy and the exposure time of the stimuli. We used the relationship between the participants’ response accuracy and the information rate of cognitive control (in bits per second, bps) in the model fitting to estimate the capacity of cognitive control. We found that the capacity of cognitive control was approximately 3 to 4 bps, demonstrating that cognitive control as a higher-level function has a remarkably low capacity. This quantification of the capacity of cognitive control may have significant theoretical and clinical implications

Collaborative Autoethnographic Writing as Communal Curative

This collaborative autoethnography reflects on how each author experienced COVID-19 and associated precarity. We explore the ways in which this experience relates to our identities (both particular and plural), and our positionalities in terms of privilege and marginality. As a collective of diverse collaborators, we confront dialectical questions of self and society. Our contributions reveal our advantage/disadvantage, mobility/immobility, and the borders and boundedness before/during/after COVID-19. We show the power of curative writing in collaborative autoethnography and how the sharing of our experiences of vulnerability represents an invitation to human connection

Soluble urokinase-type plasminogen activator receptor levels in patients with burn injuries and inhalation trauma requiring mechanical ventilation: an observational cohort study

Soluble urokinase-type plasminogen activator receptor (suPAR) has been proposed as a biologic marker of fibrinolysis and inflammation. The aim of this study was to investigate the diagnostic and prognostic value of systemic and pulmonary levels of suPAR in burn patients with inhalation trauma who need mechanical ventilation. suPAR was measured in plasma and nondirected lung-lavage fluid of mechanically ventilated burn patients with inhalation trauma. The samples were obtained on the day of inhalation trauma and on alternate days thereafter until patients were completely weaned from the mechanical ventilator. Mechanically ventilated patients without burns and without pulmonary disease served as controls. Systemic levels of suPAR in burn patients with inhalation trauma were not different from those in control patients. On admission and follow up, pulmonary levels of suPAR in patients with inhalation trauma were significantly higher compared with controls. Pulmonary levels of suPAR highly correlated with pulmonary levels of interleukin 6, a marker of inflammation, and thrombin-antithrombin complexes, markers of coagulation, but not plasminogen activator activity, a marker of fibrinolysis. Systemic levels of suPAR were predictive of the duration of mechanical ventilation and length of intensive care unit (ICU) stay. Duration of mechanical ventilation and length of ICU stay were significantly longer in burn-injury patients with systemic suPAR levels > 9.5 ng/ml. Pulmonary levels of suPAR are elevated in burn patients with inhalation trauma, and they correlate with pulmonary inflammation and coagulation. Although pulmonary levels of suPAR may have diagnostic value in burn-injury patients, systemic levels of suPAR have prognostic valu

Associations with photoreceptor thickness measures in the UK Biobank.

Spectral-domain OCT (SD-OCT) provides high resolution images enabling identification of individual retinal layers. We included 32,923 participants aged 40-69 years old from UK Biobank. Questionnaires, physical examination, and eye examination including SD-OCT imaging were performed. SD OCT measured photoreceptor layer thickness includes photoreceptor layer thickness: inner nuclear layer-retinal pigment epithelium (INL-RPE) and the specific sublayers of the photoreceptor: inner nuclear layer-external limiting membrane (INL-ELM); external limiting membrane-inner segment outer segment (ELM-ISOS); and inner segment outer segment-retinal pigment epithelium (ISOS-RPE). In multivariate regression models, the total average INL-RPE was observed to be thinner in older aged, females, Black ethnicity, smokers, participants with higher systolic blood pressure, more negative refractive error, lower IOPcc and lower corneal hysteresis. The overall INL-ELM, ELM-ISOS and ISOS-RPE thickness was significantly associated with sex and race. Total average of INL-ELM thickness was additionally associated with age and refractive error, while ELM-ISOS was additionally associated with age, smoking status, SBP and refractive error; and ISOS-RPE was additionally associated with smoking status, IOPcc and corneal hysteresis. Hence, we found novel associations of ethnicity, smoking, systolic blood pressure, refraction, IOPcc and corneal hysteresis with photoreceptor thickness

Carbon uptake and distribution in Spark Plasma Sintering (SPS) processed Sm(Co, Fe, Cu, Zr)z

Spark Plasma Sintering (SPS) rapidly consolidates high-melting point powders between carbon dies, but carbon can pose a risk for many materials. Carbon uptake in SPS and conventional, pressure-less sintered (CS) Sm(Co, Fe, Cu, Zr)z has been analysed using Electron Probe Micro-Analysis (EPMA) to produce high-detail elemental distribution maps. Field's metal was used as mounting material to avoid introducing carbon into the samples. The distribution maps show high surface carbon levels in the SPS-processed Sm(Co, Fe, Cu, Zr)z to a depth of 10 μm. Much less carbon was observed in CS Sm(Co, Fe, Cu, Zr)z. Furthermore, elemental carbon analysis (LECO-C) confirmed carbon was most abundant at the surface in SPS-processed Sm(Co, Fe, Cu, Zr)z but also at higher levels internally, when compared to the CS sample. It is inferred that the carbon contamination is due to the contact between the powder and the graphite die/paper at elevated temperatures during SPS process. The measured levels of carbon in the SPS-processed sample are not expected to significantly impact the magnetic properties of Sm(Co, Fe, Cu, Zr)z. These results may have implications for other powder materials processed by SPS with properties sensitive to carbon

Threatened North African seagrass meadows have supported green turtle populations for millennia

"Protect and restore ecosystems and biodiversity" is the second official aim of the current UN Ocean Decade (2021 to 2030) calling for the identification and protection of critical marine habitats. However, data to inform policy are often lacking altogether or confined to recent times, preventing the establishment of long-term baselines. The unique insights gained from combining bioarchaeology (palaeoproteomics, stable isotope analysis) with contemporary data (from satellite tracking) identified habitats which sea turtles have been using in the Eastern Mediterranean over five millennia. Specifically, our analysis of archaeological green turtle (Chelonia mydas) bones revealed that they likely foraged on the same North African seagrass meadows as their modern-day counterparts. Here, millennia-long foraging habitat fidelity has been directly demonstrated, highlighting the significance (and long-term dividends) of protecting these critical coastal habitats that are especially vulnerable to global warming. We highlight the potential for historical ecology to inform policy in safeguarding critical marine habitats

Investigation of associations between retinal microvascular parameters and albuminuria in UK Biobank: a cross-sectional case-control study.

BACKGROUND: Associations between microvascular variation and chronic kidney disease (CKD) have been reported previously. Non-invasive retinal fundus imaging enables evaluation of the microvascular network and may offer insight to systemic risk associated with CKD. METHODS: Retinal microvascular parameters (fractal dimension [FD] - a measure of the complexity of the vascular network, tortuosity, and retinal arteriolar and venular calibre) were quantified from macula-centred fundus images using the Vessel Assessment and Measurement Platform for Images of the REtina (VAMPIRE) version 3.1 (VAMPIRE group, Universities of Dundee and Edinburgh, Scotland) and assessed for associations with renal damage in a case-control study nested within the multi-centre UK Biobank cohort study. Participants were designated cases or controls based on urinary albumin to creatinine ratio (ACR) thresholds. Participants with ACR ≥ 3 mg/mmol (ACR stages A2-A3) were characterised as cases, and those with an ACR < 3 mg/mmol (ACR stage A1) were categorised as controls. Participants were matched on age, sex and ethnic background. RESULTS: Lower FD (less extensive microvascular branching) was associated with a small increase in odds of albuminuria independent of blood pressure, diabetes and other potential confounding variables (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.03-1.34 for arterioles and OR 1.24, CI 1.05-1.47 for venules). Measures of tortuosity or retinal arteriolar and venular calibre were not significantly associated with ACR. CONCLUSIONS: This study supports previously reported associations between retinal microvascular FD and other metabolic disturbances affecting the systemic vasculature. The association between retinal microvascular FD and albuminuria, independent of diabetes and blood pressure, may represent a useful indicator of systemic vascular damage associated with albuminuria