Disentangling Spatiotemporal Signals in Global Atmospheric Methane Columns

Methane is a major driver of atmospheric chemistry and a powerful radiative forcing agent. Thus, explaining tropospheric methane trends over the last two decades is critical for the scientific understanding of the global carbon cycle as well as the ability to predict future consequences on the climate and biosphere. Tropospheric concentrations of methane have been increasing, but the growth rate in the last two decades has been extremely variable. Long-term trends in atmospheric methane concentrations and short-term fluctuations in its growth rate are not well understood because its surface emissions and chemical loss are poorly constrained. The ranges of uncertainties for estimates of methane sources and sinks are considerably broad due to the complexity of both natural and anthropogenic fluxes and the heterogeneity of their timescales. This research takes a multifaceted approach to constraining methane fluxes and determining the causes of interannual and long-term variability by developing and synthesizing measurements, integrating methane observations with tracers of tropospheric advection, and assessing systematic biases in chemical transport models. This work synthesizes satellite, aircraft, and surface measurements, including a newly developed dataset of tropospheric column-averaged dry-air mole fractions from Fourier Transform Spectrometer (FTS) instruments within the Total Carbon Column Observing Network (TCCON). Assimilating measurements into the GEOS-Chem chemical transport model, the sensitivities of the temporal and spatial distributions of methane to changes in the distributions of sources and sinks are evaluated. We demonstrate that systematic biases in model stratospheres alias into assimilation of total column methane, masking measurement-model mismatch in tropospheric seasonality. This work also investigates the influence of large-scale transport to the spatial distribution, and in particular the interhemispheric and meridional gradients, of methane

Virtual OSCE Delivery and Quality Assurance During a Pandemic: Implications for the Future

Background: During 2020, the COVID-19 pandemic caused worldwide disruption to the delivery of clinical assessments, requiring medicals schools to rapidly adjust their design of established tools. Derived from the traditional face-to-face Objective Structured Clinical Examination (OSCE), the virtual OSCE (vOSCE) was delivered online, using a range of school-dependent designs. The quality of these new formats was evaluated remotely through virtual quality assurance (vQA). This study synthesizes the vOSCE and vQA experiences of stakeholders from participating Australian medical schools based on a Quality framework. Methods: This study utilized a descriptive phenomenological qualitative design. Focus group discussions (FGD) were held with 23 stakeholders, including examiners, academics, simulated patients, professional staff, students and quality assurance examiners. The data was analyzed using a theory-driven conceptual Quality framework. Results: The vOSCE was perceived as a relatively fit-for purpose assessment during pandemic physical distancing mandates. Additionally, the vOSCE was identified as being value-for-money and was noted to provide procedural benefits which lead to an enhanced experience for those involved. However, despite being largely delivered fault-free, the current designs are considered limited in the scope of skills they can assess, and thus do not meet the established quality of the traditional OSCE. Conclusions: Whilst virtual clinical assessments are limited in their scope of assessing clinical competency when compared with the traditional OSCE, their integration into programs of assessment does, in fact, have significant potential. Scholarly review of stakeholder experiences has elucidated quality aspects that can inform iterative improvements to the design and implementation of future vOSCEs

Assessing a 600-mg Loading Dose of Clopidogrel 24 Hours Prior to Pipeline Embolization Device Treatment

Background: Clopidogrel/aspirin antiplatelet therapy routinely is administered 7-10 days before pipeline aneurysm treatment. Our study assessed the safety and efficacy of a 600-mg loading dose of clopidogrel 24 hours before Pipeline Embolization Device (PED) treatment. Methods: In this retrospective cohort study, we included patients treated with PED from October 2010 to May 2016. A total of 39.7% (n = 158) of patients were dispensed a loading dose of 650 mg of aspirin plus at least 600 mg of clopidogrel 24 hours preceding PED deployment, compared to 60.3% (n = 240) of patients who received 81-325 mg of aspirin daily for 10 days with 75 mg of clopidogrel daily preprocedurally. The mean follow-up was 15.8 months (standard deviation [SD] 12.4 months). modified Rankin Scale (mRS) was registered before the discharge and at each follow-up visit. To control confounding, we used multivariable logistic regression and propensity score conditioning. Results: Of 398 patients, the proportion of female patients was ~16.5% (41/240) in both groups and shared the same mean of age ~56.46 years. ~12.2% (mean = 0.09; SD = 0.30) had a subarachnoid hemorrhage. 92% (mean = 0.29; SD = 0.70) from the pretreatment group and 85.7% (mean = 0.44; SD = 0.91) of the bolus group had a mRS ≤2. In multivariate analysis, bolus did not affect the mRS score, P = 0.24. Seven patients had a long-term recurrence, 2 (0.83%; mean = 0.01; SD = 0.10) of which from the pretreatment group. In a multivariable logistic regression, bolus was not associated with a long-term recurrence rate (odds ratio [OR] 1.91; 95% confidence interval [CI] 0.27-13.50; P = 0.52) or with thromboembolic accidents (OR 0.99; 95% CI 0.96-1.03; P = 0.83) nor with hemorrhagic events (OR 1.00; 95% CI 0.97-1.03; P = 0.99). Three patients died: one who received a bolus had an acute subarachnoid hemorrhage. The mean mortality rate was parallel in both groups ~0.25 (SD = 0.16). Bolus was not associated with mortality (OR 1.11; 95% CI 0.26-4.65; P = 0.89). The same associations were present in propensity score-adjusted models. Conclusions: In a cohort receiving PED, a 600-mg loading dose of clopidogrel should be safe and efficacious in those off the standard protocol or showing \u3c30% platelet inhibition before treatment

Microplastic abundance and sources in surface water samples of the Vaal River, South Africa

DATA AVAILABILITY : Data are available upon request.Microplastics (MPs) have emerged as a global environmental concern due to their persistent nature. In South Africa, microplastic research has primarily focused on marine systems. However, recent years have seen a shift in focus to studying MPs in South African freshwaters. In this study, MPs with a minimum size of 0.055 mm in surface water of the Vaal River, South Africa, were reported. MPs were 100% prevalent, with a mean numerical abundance of 0.68 ± 0.64 particles/m3. Small-sized MPs of < 1 mm accounted for the largest proportion. MPs were chemically identified as high-density polyethylene, low-density polyethylene, and polypropylene according to their Raman spectra. The prevalence of fragments (41.6%) and fibers (38.5%) over pellets (8.1%) indicates that microplastics are from secondary sources. The prevalence of polyethylene and polypropylene is consistent with microplastics being from secondary sources. These polymers are commonly used in single-use plastics, packing bags, textiles, and containers. These characteristics are of great concern due to their implications on the bioavailability and toxicological impacts of MPs. Consequently, these properties may pose more hazards to aquatic biota inhabiting the Vaal River.The Royal Society, UK, and funded by Government’s Grand Challenges Research Fund (GCRF). Open access funding provided by University of the Witwatersrand.http://link.springer.com/journal/128hj2024ChemistrySDG-06:Clean water and sanitatio

“Could You Work in My Team?”: Exploring How Professional Clinical Role Expectations Influence Decision-Making of Assessors During Exit-Level Medical School OSCEs

Decision-making in clinical assessment, such as exit-level medical school Objective Structured Clinical Examinations (OSCEs), is complex. This study utilized an empirical phenomenological qualitative approach with thematic analysis to explore OSCE assessors' perceptions of the concept of a “prototypical intern” expressed during focus group discussions. Topics discussed included the concept of a prototypical intern, qualities to be assessed, and approaches to clinical assessment decision-making. The thematic analysis was then applied to a theoretical framework (Cultural Historical Activity Theory—CHAT) that explored the complexity of making assessment decisions amidst potentially contradicting pressures from academic and clinical perspectives. Ten Australasian medical schools were involved with 15 experienced and five less experienced assessors participating. Thematic analysis of the data revealed four major themes in relation to how the prototypical intern concept influences clinical assessors' judgements: (a) Suitability of marking rubric based on assessor characteristics and expectations; (b) Competence as final year student vs. performance as a prototypical intern; (c) Safety, trustworthiness and reliability as constructs requiring assessment and (d) Contradictions in decision making process due to assessor differences. These themes mapped well within the interaction between two proposed activity systems in the CHAT model: academic and clinical. More clinically engaged and more experienced assessors tend to fall back on a heuristic, mental construct of a “prototypical intern,” to calibrate judgements, particularly, in difficult situations. Further research is needed to explore whether consensus on desirable intern qualities and their inclusion into OSCE marksheets decreases the cognitive load and increases the validity of assessor decision making

How to incorporate telemedicine in medical residency: A Brazilian experience in pediatric emergency

Introduction: The exponential growth of telehealth services during the COVID-19 pandemic led to the implementation of a telemedicine care service in a tertiary university pediatric hospital. It brought the need to develop a training aimed at remote care within the pediatric emergency rotation program. Objective: To describe the implementation of a telemedicine training for pediatric residents and present the preliminary results. Methods: Descriptive prospective study (pre and post), with&nbsp;40&nbsp;resident physicians of the first year of pediatrics. Reaction Assessments were applied before and after training, in addition to a resident physician perception questionnaire at the end of the training. Results: There was a significant difference in the resident's perception of experience and safety after initial training. Most rated the proposal as good or excellent, considered teaching telemedicine relevant and that this experience contributed to their learning on the subject. Conclusion: This study describes an innovative proposal for training in telemedicine. The preliminary results were encouraging, demonstrating the program's potential in training future pediatricians

The Developmental Trajectory of Brain-Scalp Distance from Birth through Childhood: Implications for Functional Neuroimaging

Measurements of human brain function in children are of increasing interest in cognitive neuroscience. Many techniques for brain mapping used in children, including functional near-infrared spectroscopy (fNIRS), electroencephalography (EEG), magnetoencephalography (MEG) and transcranial magnetic stimulation (TMS), use probes placed on or near the scalp. The distance between the scalp and the brain is a key variable for these techniques because optical, electrical and magnetic signals are attenuated by distance. However, little is known about how scalp-brain distance differs between different cortical regions in children or how it changes with development. We investigated scalp-brain distance in 71 children, from newborn to age 12 years, using structural T1-weighted MRI scans of the whole head. Three-dimensional reconstructions were created from the scalp surface to allow for accurate calculation of brain-scalp distance. Nine brain landmarks in different cortical regions were manually selected in each subject based on the published fNIRS literature. Significant effects were found for age, cortical region and hemisphere. Brain-scalp distances were lowest in young children, and increased with age to up to double the newborn distance. There were also dramatic differences between brain regions, with up to 50% differences between landmarks. In frontal and temporal regions, scalp-brain distances were significantly greater in the right hemisphere than in the left hemisphere. The largest contributors to developmental changes in brain-scalp distance were increases in the corticospinal fluid (CSF) and inner table of the cranium. These results have important implications for functional imaging studies of children: age and brain-region related differences in fNIRS signals could be due to the confounding factor of brain-scalp distance and not true differences in brain activity

Nanoparticle Network Formation in Nanostructured and Disordered Block Copolymer Matrices

Incorporation of nanoparticles composed of surface-functionalized fumed silica (FS) or native colloidal silica (CS) into a nanostructured block copolymer yields hybrid nanocomposites whose mechanical properties can be tuned by nanoparticle concentration and surface chemistry. In this work, dynamic rheology is used to probe the frequency and thermal responses of nanocomposites composed of a symmetric poly(styrene-b-methyl methacrylate) (SM) diblock copolymer and varying in nanoparticle concentration and surface functionality. At sufficiently high loading levels, FS nanoparticle aggregates establish a load-bearing colloidal network within the copolymer matrix. Transmission electron microscopy images reveal the morphological characteristics of the nanocomposites under these conditions