Mosquito Microbiomes of Rwanda: Characterizing Mosquito Host and Microbial Communities in the Land of a Thousand Hills.

Mosquitoes are a complex nuisance around the world and tropical countries bear the brunt of the burden of mosquito-borne diseases. Rwanda has had success in reducing malaria and some arboviral diseases over the last few years, but still faces challenges to elimination. By building our understanding of in situ mosquito communities in Rwanda at a disturbed, human-occupied site and at a natural, preserved site, we can build our understanding of natural mosquito microbiomes toward the goal of implementing novel microbial control methods. Here, we examined the composition of collected mosquitoes and their microbiomes at two diverse sites using Cytochrome c Oxidase I sequencing and 16S V4 high-throughput sequencing. The majority (36 of 40 species) of mosquitoes captured and characterized in this study are the first-known record of their species for Rwanda but have been characterized in other nations in East Africa. We found significant differences among mosquito genera and among species, but not between mosquito sexes or catch method. Bacteria of interest for arbovirus control, Asaia, Serratia, and Wolbachia, were found in abundance at both sites and varied greatly by species.

Quantitative T1 brain mapping in early relapsing-remitting multiple sclerosis: longitudinal changes, lesion heterogeneity and disability.

OBJECTIVES: To quantify brain microstructural changes in recently diagnosed relapsing-remitting multiple sclerosis (RRMS) using longitudinal T1 measures, and determine their associations with clinical disability. METHODS: Seventy-nine people with recently diagnosed (< 6 months) RRMS were recruited from a single-centre cohort sub-study, and underwent baseline and 1-year brain MRI, including variable flip angle T1 mapping. Median T1 was measured in white matter lesions (WML), normal-appearing white matter (NAWM), cortical/deep grey matter (GM), thalami, basal ganglia and medial temporal regions. Prolonged T1 (≥ 2.00 s) and supramedian T1 (relative to cohort WML values) WML voxel counts were also measured. Longitudinal change was assessed with paired t-tests and compared with Bland-Altman limits of agreement from healthy control test-retest data. Regression analyses determined relationships with Expanded Disability Status Scale (EDSS) score and dichotomised EDSS outcomes (worsening or stable/improving). RESULTS: Sixty-two people with RRMS (mean age 37.2 ± 10.9 [standard deviation], 48 female) and 11 healthy controls (age 44 ± 11, 7 female) contributed data. Prolonged and supramedian T1 WML components increased longitudinally (176 and 463 voxels, respectively; p < .001), and were associated with EDSS score at baseline (p < .05) and follow-up (supramedian: p < .01; prolonged: p < .05). No cohort-wide median T1 changes were found; however, increasing T1 in WML, NAWM, cortical/deep GM, basal ganglia and thalami was positively associated with EDSS worsening (p < .05). CONCLUSION: T1 is sensitive to brain microstructure changes in early RRMS. Prolonged WML T1 components and subtle changes in NAWM and GM structures are associated with disability. CLINICAL RELEVANCE STATEMENT: MRI T1 brain mapping quantifies disability-associated white matter lesion heterogeneity and subtle microstructural damage in normal-appearing brain parenchyma in recently diagnosed RRMS, and shows promise for early objective disease characterisation and stratification. KEY POINTS: • Quantitative T1 mapping detects brain microstructural damage and lesion heterogeneity in recently diagnosed relapsing-remitting multiple sclerosis. • T1 increases in lesions and normal-appearing parenchyma, indicating microstructural damage, are associated with worsening disability. • Brain T1 measures are objective markers of disability-relevant pathology in early multiple sclerosis.

The Mycobiome of Bats in the American Southwest Is Structured by Geography, Bat Species, and Behavior.

Bats are widespread mammals that play key roles in ecosystems as pollinators and insectivores. However, there is a paucity of information about bat-associated microbes, in particular their fungal communities, despite the important role microbes play in host health and overall host function. The emerging fungal disease, white-nose syndrome, presents a potential challenge to the bat microbiome and understanding healthy bat-associated taxa will provide valuable information about potential microbiome-pathogen interactions. To address this knowledge gap, we collected 174 bat fur/skin swabs from 14 species of bats captured in five locations in New Mexico and Arizona and used high-throughput sequencing of the fungal internal transcribed (ITS) region to characterize bat-associated fungal communities. Our results revealed a highly heterogeneous bat mycobiome that was structured by geography and bat species. Furthermore, our data suggest that bat-associated fungal communities are affected by bat foraging, indicating the bat skin microbiota is dynamic on short time scales. Finally, despite the strong effects of site and species, we found widespread and abundant taxa from several taxonomic groups including the genera Alternaria and Metschnikowia that have the potential to be inhibitory towards fungal and bacterial pathogens.

Chronic stress and captivity alter the cloacal microbiome of a wild songbird.

There are complex interactions between an organism's microbiome and its response to stressors, often referred to as the 'gut-brain axis'; however, the ecological relevance of this axis in wild animals remains poorly understood. Here, we used a chronic mild stress protocol to induce stress in wild-caught house sparrows (Passer domesticus), and compared microbial communities among stressed animals, those recovering from stress, captive controls (unstressed) and a group not brought into captivity. We assessed changes in microbial communities and abundance of shed microbes by culturing cloacal samples on multiple media to select for aerobic and anaerobic bacteria and fungi. We complemented this with cultivation-independent 16S and ITS rRNA gene amplification and sequencing, pairing these results with host physiological and immune metrics, including body mass change, relative spleen mass and plasma corticosterone concentrations. We found significant effects of stress and captivity on the house sparrow microbiomes, with stress leading to an increased relative abundance of endotoxin-producing bacteria - a possible mechanism for the hyperinflammatory response observed in captive avians. While we found evidence that the microbiome community partially recovers after stress cessation, animals may lose key taxa, and the abundance of endotoxin-producing bacteria persists. Our results suggest an overall link between chronic stress, host immune system and the microbiome, with the loss of potentially beneficial taxa (e.g. lactic acid bacteria), and an increase in endotoxin-producing bacteria due to stress and captivity. Ultimately, consideration of the host's microbiome may be useful when evaluating the impact of stressors on individual and population health.

Prevalence of multimorbidity and its impact on survival in people with motor neuron disease.

BACKGROUND AND PURPOSE: This study was undertaken to determine the prevalence of multimorbidity in people with motor neuron disease (MND) and to identify whether specific patterns of multimorbidity impact survival beyond age alone. METHODS: We performed a retrospective analysis of the Scottish national MND register from 1 January 2015 to 29 October 2019. People with amyotrophic lateral sclerosis, primary lateral sclerosis, progressive muscular atrophy, or progressive bulbar palsy were included. We fitted latent class regression models incorporating comorbidities (class indicators), age, sex, and bulbar onset (covariates), and survival (distal outcome) with multimorbidity as a hypothesised latent variable. We also investigated the association between the Charlson Comorbidity Index and survival in Cox regression and compared its discrimination and calibration to age alone. RESULTS: A total of 937 people with MND were identified (median age = 67 years, 60.2% male); 64.8% (n = 515) had two or more comorbidities. We identified a subpopulation with high prevalence of cardiovascular disease, but when accounting for the relationship between age and individual comorbidities, there was no difference in survival. Both Charlson Comorbidity Index (hazard ratio [HR] per unit increase = 1.11, 95% confidence interval [CI] = 1.07-1.15, p < 0.0001) and age (HR per year increase = 1.04, 95% CI = 1.03-1.05, p < 0.0001) were significantly associated with survival, but discrimination was higher for age compared to Charlson Comorbidity Index (C-index = 0.63 vs. 0.59). CONCLUSIONS: Multimorbidity is common in MND, necessitating holistic interdisciplinary management, but age is the dominant predictor of prognosis in people with MND. Excluding people with MND and multimorbidity from trial participation may do little to homogenise the cohort in terms of survival potential and could harm generalisability.

Long-Term Fertilization Alters Nitrous Oxide Cycling Dynamics in Salt Marsh Sediments.

Salt marsh sediments are known hotspots for nitrogen cycling, including the production and consumption of nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting agent. Coastal eutrophication, particularly elevated nitrogen loading from the application of fertilizers, is accelerating nitrogen cycling processes in salt marsh sediments. Here, we examine the impact of long-term fertilization on nitrogen cycling processes with a focus on N2O dynamics in a New England salt marsh. By combining 15N-tracer experiments with numerical modeling, we found that both nitrification and denitrification contribute to net N2O production in fertilized sediments. Long-term fertilization increased the relative importance of nitrification to N2O production, likely a result of increased oxygen penetration from nutrient-induced increases in marsh elevation. Substrate utilization rates of key nitrogen cycling processes revealed links between functions and the corresponding microbial communities. Higher specific substrate utilization rates leading to N2O production from nitrification in fertilized sediments indicate a shift in the community composition of ammonia oxidizers, whereas the lack of change in specific substrate utilization of N2O production from denitrification under long-term fertilization suggests resilience of the denitrifying communities. Both are consistent with previous studies on the functional gene community composition in these experimental plots.

Questioning the regressivity of tobacco taxes: a distributional accounting impact model of increased tobacco taxation.

BACKGROUND: Tobacco taxes, as with other 'sin taxes', are generally regarded as a highly cost-effective mechanism to reduce consumption but are often considered by policymakers to be regressive, undermining efforts to fully implement them at levels recommended by the WHO due to concerns of fairness. We aim to demonstrate whether there are circumstances in which the impacts of additional tobacco taxes are not regressive, using a standard income-share accounting definition of tax burden. METHODS AND FINDINGS: We apply mathematical modelling and explore the hypothetical distributions in the net change in tobacco taxes and cigarette expenditures by income group, following an increase in tobacco taxation. The hypothetical distribution per income group of additional taxes and cigarette expenditures borne by individuals following tobacco tax hikes was calculated with respect to a selection of parameters including: the change in the retail price of cigarettes, the price elasticity of demand for tobacco, smoking prevalence, cigarette consumption and individual income. We determine the range of hypothetical parameter values for which increased tobacco taxation should not be considered to penalise the poorest income groups when examining marginal cigarette consumption expenditures and using an accounting definition of tax burden. CONCLUSIONS: Our findings question the doctrine that tobacco taxes are uniformly regressive from a standard income-share accounting view and point to the importance of the specific features of tax policy to shape a progressive approach to tobacco taxation: tobacco tax increases are less likely to be regressive when accompanied by a broad framework of demand-side measures that enhance the capacity of low-income smokers to quit tobacco use.

Non-invasive risk scores do not reliably identify future cirrhosis or hepatocellular carcinoma in Type 2 diabetes: The Edinburgh type 2 diabetes study.

BACKGROUND: The incidence of cirrhosis and hepatocellular carcinoma (HCC) is increased in Type 2 diabetes, primarily secondary to non-alcoholic fatty liver disease (NAFLD). European guidelines recommend screening for NAFLD in Type 2 diabetes. American guidelines, while not advocating a screening protocol, suggest using non-invasive markers of fibrosis for risk-stratification and guiding onward referral. AIMS: To test the ability of individual fibrosis scores and the European screening algorithm to predict 11-year incident cirrhosis/HCC in an asymptomatic community cohort of older people with Type 2 diabetes. METHODS: The Edinburgh Type 2 Diabetes Study investigated men and women with Type 2 diabetes (n = 1066, aged 60-75 at baseline). Liver markers were measured at baseline and year 1; steatosis and fibrosis markers were calculated according to independently published calculations. During 11 years of follow-up, cases of cirrhosis and HCC were identified. RESULTS: Forty-three out of 1059 participants with no baseline cirrhosis/HCC developed incident disease. All scores were significantly associated with incident liver disease by odds ratio (P < .05). The ability of the risk-stratification tools to accurately identify those who developed incident cirrhosis/HCC was poor with low-positive predictive values (5-46%) and high false-negative and -positive rates (up to 60% and 77%) respectively. When fibrosis risk scores were used in conjunction with the European algorithm, they performed modestly better than when applied in isolation. CONCLUSIONS: In a cohort with a moderately low incidence of cirrhosis/HCC, existing risk scores did not reliably identify participants at high risk. Better prediction models for cirrhosis/HCC in people with Type 2 diabetes are required.

Establishment Limitation Constrains the Abundance of Lactic Acid Bacteria in the Napa Cabbage Phyllosphere.

Patterns of phyllosphere diversity have become increasingly clear with high-throughput sequencing surveys, but the processes that control phyllosphere diversity are still emerging. Through a combination of lab and field experiments using Napa cabbage and lactic acid bacteria (LAB), we examined how dispersal and establishment processes shape the ecological distributions of phyllosphere bacteria. We first determined the abundance and diversity of LAB on Napa cabbage grown at three sites using both culture-based approaches and 16S rRNA gene amplicon sequencing. Across all sites, LAB made up less than 0.9% of the total bacterial community abundance. To assess whether LAB were low in abundance in the Napa cabbage phyllosphere due to a limited abundance in local species pools (source limitation), we quantified LAB in leaf and soil samples across 51 vegetable farms and gardens throughout the northeastern United States. Across all sites, LAB comprised less than 3.2% of the soil bacterial communities and less than 1.6% of phyllosphere bacterial communities. To assess whether LAB are unable to grow in the phyllosphere even if they dispersed at high rates (establishment limitation), we used a gnotobiotic Napa cabbage system in the lab with experimental communities mimicking various dispersal rates of LAB. Even at high dispersal rates, LAB became rare or completely undetectable in experimental communities, suggesting that they are also establishment limited. Collectively, our data demonstrate that the low abundance of LAB in phyllosphere communities may be explained by establishment limitation.IMPORTANCE The quality and safety of vegetable fermentations are dependent on the activities of LAB naturally present in the phyllosphere. Despite their critical role in determining the success of fermentation, the processes that determine the abundance and diversity of LAB in vegetables used for fermentation are poorly characterized. Our work demonstrates that the limited ability of LAB to grow in the cabbage phyllosphere environment may constrain their abundance on cabbage leaves. These results suggest that commercial fermentation of Napa cabbage proceeds despite low and variable abundances of LAB across different growing regions. Propagule limitation may also explain ecological distributions of other rare members of phyllosphere microbes.

Nutrient Enrichment Alters Salt Marsh Fungal Communities and Promotes Putative Fungal Denitrifiers.

Enrichment of ecosystems with excess nutrients is occurring at an alarming rate and has fundamentally altered ecosystems worldwide. Salt marshes, which lie at the land-sea interface, are highly effective at removing anthropogenic nutrients through the action of macrophytes and through microbial processes in coastal sediments. The response of salt marsh bacteria to excess nitrogen has been documented; however, the role of fungi and their response to excess nitrogen in salt marsh sediments is not fully understood. Here, we document the response of salt marsh fungal communities to long-term excess nitrate in four distinct marsh habitats within a northern temperate marsh complex. We show that salt marsh fungal communities varied as a function of salt marsh habitat, with both fungal abundance and diversity increasing with carbon quantity. Nutrient enrichment altered fungal communities in all habitats through an increase in fungal abundance and the proliferation of putative fungal denitrifiers. Nutrient enrichment also altered marsh carbon quality in low marsh surface sediments where fungal response to nutrient enrichment was most dramatic, suggesting nutrient enrichment can alter organic matter quality in coastal sediments. Our results indicate that fungi, in addition to bacteria, likely play an important role in anaerobic decomposition of salt marsh sediment organic matter.

Nitrifying and Denitrifying Bacterial Communities in Advanced Nitrogen-Removal Onsite Wastewater Treatment Systems.

Advanced N-removal onsite wastewater treatment systems (OWTS) rely on nitrification and denitrification to remove N from wastewater. Despite their use to reduce N contamination, we know little about microbial communities controlling N removal in these systems. We used quantitative polymerase chain reaction and high-throughput sequencing targeting nitrous oxide reductase () and bacterial ammonia monooxygenase () to determine the size, structure, and composition of communities containing these genes. We analyzed water samples from three advanced N-removal technologies in 38 systems in five towns in Rhode Island in August 2016, and in nine systems from one town in June, August, and October 2016. Abundance of ranged from 9.1 × 10 to 9 × 10 copies L and differed among technologies and over time, whereas bacterial abundance ranged from 0 to 1.9 × 10 copies L and was not different among technologies or over time. Richness and diversity of -but not -differed over time, with median Shannon diversity indices ranging from 2.61 in October to 4.53 in August. We observed weak community similarity patterns driven by geography and technology in The most abundant and containing bacteria were associated with water distribution and municipal wastewater treatment plants, such as and species. Our results show that communities in N-removal OWTS technologies differ slightly in terms of size and diversity as a function of time, but not geography, whereas communities are similar across time, technology, and geography. Furthermore, community composition appears to be stable across technologies, geography, and time for .

The Impact of Physician Assistants on a Breast Reconstruction Practice: Outcomes and Cost Analysis.

BACKGROUND: Physician assistants (PAs) are commonly employed in plastic surgery. However, limited data exist on their impact, which may guide decisions regarding how best to integrate them into practice. METHODS: A review of the practices of 2 breast reconstructive surgeons was performed. A comparison was made between a 1-year period before to a 1-year period after the addition of a PA into practice. The practice model was a one-to-one pairing of a plastic surgeon and a PA. RESULTS: A total of 4141 clinic encounters and 1356 surgical cases were reviewed. After the addition of PAs, there was a significant increase in relative value units (1057 vs 1323 per month per surgeon, P < 0.001). Operative times were similar with and without PAs (P = 0.45). However, clinic encounter times for surgeons were shorter for all visit types when patients were first seen by a PA before the surgeon: global follow-up (P = 0.03), other follow-up (P = 0.002), consultation (P = 0.76), and preoperative (P = 0.02), translating to 9 additional patients seen per day. Charges (P = 0.001) and payments (P = 0.007) also increased, which offset the cost of using a PA. However, the financial contribution from PA involvement as first assistant in surgery was limited (5.2%). The peak effect of PAs was observed between the third and fourth quarters. CONCLUSIONS: In breast reconstruction, PAs primarily enhance the efficiency of plastic surgeons, particularly in the clinic, with downstream clinical and financial gains of an indirect nature for surgeons.

The skin microbiome of cow-nose rays (Rhinoptera bonasus) in an aquarium touch-tank exhibit.

Public aquaria offer numerous educational opportunities for visitors while touch-tank exhibits offer guests the ability to directly interact with marine life via physical contact. Despite the popularity of touch-tanks, there is a paucity of research about animal health in these exhibits and, in particular, there is little research on the microbial communities in these highly interactive exhibits. Microbial community structure can have implications for both host health and habitat function. To better understand the microbiome of a touch-tank we used high-throughput sequencing of the 16S rRNA gene to analyze the microbial community on the dorsal and ventral surfaces of cow-nose rays (Rhinoptera bonasus) as well as their environment in a frequently visited touch-tank exhibit at the New England Aquarium. Our analyses revealed a distinct microbial community associated with the skin of the ray that had lower diversity than the surrounding habitat. The ray skin was dominated by three orders: Burkholderiales (∼55%), Flavobacteriales (∼19%), and Pseudomonadales (∼12%), taxonomic groups commonly associated with other fish species. Our results provide a survey of ray-associated bacterial communities in a touch-tank environment, thereby laying the foundation for future studies examining the role of potential challenges to ray microbiota and their associated health.

Diabetes Care Management Teams Did Not Reduce Utilization When Compared With Traditional Care: A Randomized Cluster Trial.

PURPOSE: Health services research evaluates redesign models for primary care. Care management is one alternative. Evaluation includes resource utilization as a criterion. Compare the impact of care-manager teams on resource utilization. The comparison includes entire panes of patients and the subset of patients with diabetes. DESIGN: Randomized, prospective, cohort study comparing change in utilization rates between groups, pre- and post-intervention. METHODOLOGY: Ten primary care physician panels in a safety-net setting. Ten physicians were randomized to either a care-management approach (Group 1) or a traditional approach (Group 2). Care managers focused on diabetes and the cardiovascular cluster of diseases. Analysis compared rates of hospitalization, 30-day readmission, emergency room visits, and urgent care visits. Analysis compared baseline rates to annual rates after a yearlong run-in for entire panels and the subset of patients with diabetes. RESULTS: Resource utilization showed no statistically significant change between baseline and Year 3 (P=.79). Emergency room visits and hospital readmission increased for both groups (P=.90), while hospital admissions and urgent care visits decreased (P=.73). Similarly, utilization was not significantly different for patients with diabetes (P=.69). CONCLUSIONS: A care-management team approach failed to improve resource utilization rates by entire panels and the subset of diabetic patients compared to traditional care. This reinforces the need for further evidentiary support for the care-management model's hypothesis in the safety net.

Frequency comb SFG: a new approach to multiplex detection.

Determination of molecular orientation at interfaces by vibrational sum frequency generation spectroscopy (VSFG) requires measurements using at least two different polarization combinations of the incoming visible, IR, and generated SFG beams. We present a new method for the simultaneous collection of different VSFG polarization outputs by use of a modified 4f pulseshaper to create a simple frequency comb. Via the frequency comb, two visible pulses are separated spectrally but aligned in space and time to interact at the sample with mixed polarization IR light. This produces two different VSFG outputs that are separated by their frequencies at the monochromator rather than their polarizations. Spectra were collected from organic thin films with different polarization combinations to show the reliability of the method. The results show that the optical arrangement is immune to fluctuations in laser power, beam pointing, and IR spectral shape.

Diminazene attenuates pulmonary hypertension and improves angiogenic progenitor cell functions in experimental models.

RATIONALE: Studies have demonstrated that angiotensin-converting enzyme 2 (ACE2) plays a protective role against lung diseases, including pulmonary hypertension (PH). Recently, an antitrypanosomal drug, diminazene aceturate (DIZE), was shown to exert an "off-target" effect of enhancing the enzymatic activity of ACE2 in vitro. OBJECTIVES: To evaluate the pharmacological actions of DIZE in experimental models of PH. METHODS: PH was induced in male Sprague Dawley rats by monocrotaline, hypoxia, or bleomycin challenge. Subsets of animals were simultaneously treated with DIZE. In a separate set of experiments, DIZE was administered after 3 weeks of PH induction to determine whether the drug could reverse PH. MEASUREMENTS AND MAIN RESULTS: DIZE treatment significantly prevented the development of PH in all of the animal models studied. The protective effects were associated with an increase in the vasoprotective axis of the lung renin-angiotensin system, decreased inflammatory cytokines, improved pulmonary vasoreactivity, and enhanced cardiac function. These beneficial effects were abolished by C-16, an ACE2 inhibitor. Initiation of DIZE treatment after the induction of PH arrested disease progression. Endothelial dysfunction represents a hallmark of PH pathophysiology, and growing evidence suggests that bone marrow-derived angiogenic progenitor cells contribute to endothelial homeostasis. We observed that angiogenic progenitor cells derived from the bone marrow of monocrotaline-challenged rats were dysfunctional and were repaired by DIZE treatment. Likewise, angiogenic progenitor cells isolated from patients with PH exhibited diminished migratory capacity toward the key chemoattractant stromal-derived factor 1α, which was corrected by in vitro DIZE treatment. CONCLUSIONS: Our results identify a therapeutic potential of DIZE in PH therapy.

Viral etiology of hospitalized acute lower respiratory infections in children under 5 years of age -- a systematic review and meta-analysis.

AIM: To estimate the proportional contribution of influenza viruses (IV), parainfluenza viruses (PIV), adenoviruses (AV), and coronaviruses (CV) to the burden of severe acute lower respiratory infections (ALRI). METHODS: The review of the literature followed PRISMA guidelines. We included studies of hospitalized children aged 0-4 years with confirmed ALRI published between 1995 and 2011. A total of 51 studies were included in the final review, comprising 56091 hospitalized ALRI episodes. RESULTS: IV was detected in 3.0% (2.2%-4.0%) of all hospitalized ALRI cases, PIV in 2.7% (1.9%-3.7%), and AV in 5.8% (3.4%-9.1%). CV are technically difficult to culture, and they were detected in 4.8% of all hospitalized ALRI patients in one study. When respiratory syncytial virus (RSV) and less common viruses were included, at least one virus was detected in 50.4% (40.0%-60.7%) of all hospitalized severe ALRI episodes. Moreover, 21.9% (17.7%-26.4%) of these viral ALRI were mixed, including more than one viral pathogen. Among all severe ALRI with confirmed viral etiology, IV accounted for 7.0% (5.5%-8.7%), PIV for 5.8% (4.1%-7.7%), and AV for 8.8% (5.3%-13.0%). CV was found in 10.6% of virus-positive pneumonia patients in one study. CONCLUSIONS: This article provides the most comprehensive analysis of the contribution of four viral causes to severe ALRI to date. Our results can be used in further cost-effectiveness analyses of vaccine development and implementation for a number of respiratory viruses.

Assessment of ChatGPT's performance on neurology written board examination questions.

Background and objectives: ChatGPT has shown promise in healthcare. To assess the utility of this novel tool in healthcare education, we evaluated ChatGPT's performance in answering neurology board exam questions. Methods: Neurology board-style examination questions were accessed from BoardVitals, a commercial neurology question bank. ChatGPT was provided a full question prompt and multiple answer choices. First attempts and additional attempts up to three tries were given to ChatGPT to select the correct answer. A total of 560 questions (14 blocks of 40 questions) were used, although any image-based questions were disregarded due to ChatGPT's inability to process visual input. The artificial intelligence (AI) answers were then compared with human user data provided by the question bank to gauge its performance. Results: Out of 509 eligible questions over 14 question blocks, ChatGPT correctly answered 335 questions (65.8%) on the first attempt/iteration and 383 (75.3%) over three attempts/iterations, scoring at approximately the 26th and 50th percentiles, respectively. The highest performing subjects were pain (100%), epilepsy & seizures (85%) and genetic (82%) while the lowest performing subjects were imaging/diagnostic studies (27%), critical care (41%) and cranial nerves (48%). Discussion: This study found that ChatGPT performed similarly to its human counterparts. The accuracy of the AI increased with multiple attempts and performance fell within the expected range of neurology resident learners. This study demonstrates ChatGPT's potential in processing specialised medical information. Future studies would better define the scope to which AI would be able to integrate into medical decision making.

A National Survey of Perspectives of Physician Assistants in Academic Plastic and Reconstructive Surgery.

Physician assistants (PAs) are an essential part of the healthcare team who improve access and efficiencies in patient care. A better understanding of the impact and current utilization of PAs in plastic and reconstructive surgery is needed. The purpose of this national survey was to evaluate the role and scope of practice of PAs in academic plastic surgery, as well as characterize current trends of PA utilization, compensation, and perceived value from a PA perspective. Methods: A voluntary, anonymous 50-question survey was distributed via SurveyMonkey to practicing PAs at 98 academic plastic surgery programs. The survey included questions about employment characteristics, involvement in clinical research and academic work, structural organization, academic benefits, compensation, and position held. Results: Ninety-one PAs from 35 plastic surgery programs completed the survey and were included (overall program response rate = 36.8%, participants response rate = 30.4%). Practice environments included outpatient clinics, the operating room, and inpatient care. Most commonly, respondents supported multiple surgeons as opposed to one surgeon's practice. For 57% of respondents, compensation is based on a tiered system that accounts for specialty and experience. The reported mode base salary range corroborates national averages and most reported annual bonuses based on merit. The majority of respondents felt valued in their role. Conclusions: Through this national survey, we provide granularity as to how PAs are utilized and compensated in academic plastic surgery. We offer insight into the overall perceived value from a PA perspective that helps define the role and will ultimately help strengthen collaboration.