Life-history stage influences immune investment and oxidative stress in response to environmental heterogeneity in Antarctic fur seals.

Immune defenses are crucial for survival but costly to develop and maintain. Increased immune investment is therefore hypothesized to trade-off with other life-history traits. Here, we examined innate and adaptive immune responses to environmental heterogeneity in wild Antarctic fur seals. In a fully crossed, repeated measures design, we sampled 100 pups and their mothers from colonies of contrasting density during seasons of contrasting food availability. Biometric and cortisol data as well as blood for the analysis of 13 immune and oxidative status markers were collected at two key life-history stages. We show that immune responses of pups are more responsive than adults to variation in food availability, but not population density, and are modulated by cortisol and condition. Immune investment is associated with different oxidative status markers in pups and mothers. Our results suggest that early life stages show greater sensitivity to extrinsic and intrinsic effectors, and that immunity may be a strong target for natural selection even in low-pathogen environments such as Antarctica.

At-focus scanning ptychography for high resolution imaging with a wide field of view.

From manufacturing to medicine, there is a demand for phase-resolved, high resolution imaging of large samples. Here we present at-focus scanning ptychography (AFSP), a novel ptychographic metrology station designed for high resolution imaging over a large field of view. AFSP builds on scanning ptychography, but samples remain stationary during the imaging process, allowing for in-situ imaging. We demonstrate a resolution of 44.19µm, present images of spherical and freeform optics with a FOV of over 4cm, and validate the fidelity of the AFSP system by comparing it to established commercial instruments. AFSP's comparable performance underscores its credibility as a valuable addition to quantitative phase imaging technologies.

Three-stage modeling of HIV infection and implications for antiretroviral therapy.

We consider a deterministic model of HIV infection that involves macrophages as a long-term active reservoir to describe all three stages of the disease process: the acute stage, chronic infection, and the transition to AIDS. The proposed model is shown to retain crucial properties, such as the positivity of solutions, regardless of variations in model parameters. A dynamical analysis is performed to identify the local stability properties of the viral clearance steady state. This analysis illustrates how chronically infected macrophages can explain the progression to AIDS and provoke viral explosion, while previous models do not. We further demonstrate that the infected T-cell population, even if not responsible for the majority of new infections that lead to viral explosion, may contribute significantly to the transition amongst the three stages of infection. Moreover, we explore the implications of the model for the administration of antiretroviral therapy (ART) and provide quantitative estimates that emphasize the time sensitive nature of treatment initiation and the level of drug efficacy. Finally, we study the effects of treatment interruption on the disease dynamics predicted by the model and elucidate the influence of both interruption time and duration.

Implementing Public Health Modules as an Approach to Improve Knowledge and Attitudes of Medical Students: A Student-Led, Multiyear Study.

PURPOSE: Public health is a necessary focus of modern medical education. However, while numerous studies demonstrate benefits of public health education during medical school among self-selected students (i.e., those interested in public health), there are few educational models shown to be effective across the general medical student population. This study examined the effect of a multiyear, case-based, longitudinal online public health curriculum required for all medical students at an urban, research-focused U.S. medical school. METHOD: The authors created 11 short public health modules to supplement a year-long, organ-based preclerkship course at Columbia University Vagelos College of Physicians and Surgeons. Beginning in 2020, all students were required to complete these modules, with repeated surveys to assess changes in attitudes and knowledge of public health over time. The authors compared responses for these domains before and after each module, across multiple time points throughout the year, and cross-sectionally to a 2019 cohort of students who were not provided the modules. RESULTS: Across 3 cohorts, 405 of 420 (96.4%) students provided responses and were included in subsequent analyses. After completing the modules, students reported perceiving a greater importance of public health to nearly every medical specialty ( P < .001), more positive attitudes toward public health broadly ( P < .001), and increased knowledge of public health content ( P < .001). These findings were consistent across longitudinal analysis of students throughout the year-long course and when compared to the cohort who did not complete the modules. CONCLUSIONS: Case-based, interactive, and longitudinal public health content can be effectively integrated into the required undergraduate medical education curriculum to improve all medical students' knowledge and perceptions of public health. Incorporating evidence-based public health education into medical training may help future physicians to better address the needs of the communities and populations in which they practice.

Comprehensive evaluations of a prototype full field-of-view photon counting CT system through phantom studies.

Objective. Photon counting CT (PCCT) has been a research focus in the last two decades. Recent studies and advancements have demonstrated that systems using semiconductor-based photon counting detectors (PCDs) have the potential to provide better contrast, noise and spatial resolution performance compared to conventional scintillator-based systems. With multi-energy threshold detection, PCD can simultaneously provide the photon energy measurement and enable material decomposition for spectral imaging. In this work, we report a performance evaluation of our first CdZnTe-based prototype full-size PCCT system through various phantom imaging studies.Approach.This prototype system supports a 500 mm scan field-of-view and 10 mmz-coverage at isocenter. Phantom scans were acquired using 120 kVp from 50 to 400 mAs to assess the imaging performance on: CT number accuracy, uniformity, noise, spatial resolution, material differentiation and quantification.Main results.Both qualitative and quantitative evaluations show that PCCT, under the tested conditions, has superior imaging performance with lower noise and improved spatial resolution compared to conventional energy integrating detector (EID)-CT. Using projection domain material decomposition approach with multiple energy bin measurements, PCCT virtual monoenergetic images have lower noise, and good accuracy in quantifying iodine and calcium concentrations. These results lead to increased contrast-to-noise ratio (CNR) for both high and low contrast study objects compared to EID-CT at matched dose and spatial resolution. PCCT can also generate super-high resolution images using much smaller detector pixel size than EID-CT and greatly improve image spatial resolution.Significance.Improved spatial resolution and quantification accuracy with reduced image noise of the PCCT images can potentially lead to better diagnosis at reduced radiation dose compared to conventional EID-CT. Increased CNR achieved by PCCT suggests potential reduction in iodine contrast media load, resulting in better patient safety and reduced cost.

Plastic surgery online, how accessible are our units?

BACKGROUND: The Covid-19 pandemic has highlighted the importance of remote patient and professional communication. This has been especially important for highly specialised and regionally-based specialties such as plastic surgery. The aim of this study was to review how UK plastic surgery units represent themselves online and their phone accessibility. PATIENTS AND METHODS: UK plastic surgery units were identified using the BAPRAS website and their websites and telephone accessibility assessed. RESULTS: Whilst a minority of units have clearly invested heavily in ensuring comprehensive webpages, nearly a third have no dedicated webpage at all. We found significant variation in quality and user-friendliness of online resources both for patients and for other healthcare professionals, with less than a quarter of units providing comprehensive contact details, emergency referral guidance, or information about changes to services due to Covid-19, to highlight a few areas. Communication with the BAPRAS website was also poor with less than half of web-links connecting to correct and relevant webpage and only 13.5% of phone numbers connecting directly to a useful plastic surgery number. In the phone component of our study we found that 47% of calls to 'direct' numbers went to voicemail but wait-times were significantly less than going through hospital switchboards and connections were more accurate. CONCLUSION: In a world where a business' credibility is so heavily based on their online appearance and, in an increasingly online era of medicine, we hope that this study may be a resource for units to improve their web-based resources and prompt further research in enhancing patient experience online.

Unique trackway on Permian Karoo shoreline provides evidence of temnospondyl locomotory behaviour.

Large-bodied temnospondyl amphibians were the dominant predators in non-marine aquatic ecosystems from the Carboniferous to the Middle Triassic. In the Permian-aged lower Beaufort Group of the main Karoo Basin, South Africa, temnospondyls are represented exclusively by the family Rhinesuchidae and are well represented by body fossils, whereas trace fossils are scarce. Accordingly, most interpretations of the behaviour of this family are based on skeletal morphology and histological data. Here we document the sedimentology and palaeontology of a late Permian palaeosurface situated immediately below the palaeoshoreline of the Ecca Sea (transition from the Ecca Group to the Beaufort Group) near the town of Estcourt in KwaZulu-Natal Province. The surface preserves numerous ichnofossils, including tetrapod footprints and fish swim-trails, but most striking are seven body impressions and associated swim trails that we attribute to a medium-sized (~1.9 m long) rhinesuchid temnospondyl. These provide valuable insight into the behaviour of these animals. The sinuous shape of some of the traces suggest that the tracemaker swam with continuous sub-undulatory propulsion of the tail.

Low heritability and high phenotypic plasticity of salivary cortisol in response to environmental heterogeneity in a wild pinniped.

Individuals are unique in how they interact with and respond to their environment. Correspondingly, unpredictable challenges or environmental stressors often produce an individualized response of the hypothalamic-pituitary-adrenal (HPA) axis and its downstream effector cortisol. We used a fully crossed, repeated measures design to investigate the factors shaping individual variation in baseline cortisol in Antarctic fur seal pups and their mothers. Saliva samples were collected from focal individuals at two breeding colonies, one with low and the other with high density, during two consecutive years of contrasting food availability. Mothers and pups were sampled concurrently at birth and shortly before weaning, while pups were additionally sampled every 20 days. We found that heritability was low for baseline cortisol, while within-individual repeatability and among-individual variability were high. A substantial proportion of the variation in baseline cortisol could be explained in pups and mothers by a combination of intrinsic and extrinsic factors including sex, weight, day, season, and colony of birth. Our findings provide detailed insights into the individualization of endocrine phenotypes and their genetic and environmental drivers in a wild pinniped. Furthermore, the strong associations between cortisol and life history traits that we report in fur seals could have important implications for understanding the population dynamics of species impacted by environmental change.

Movement patterns and activity levels are shaped by the neonatal environment in Antarctic fur seal pups.

Tracking studies of juveniles are rare compared to those of adults, and consequently little is known about the influence of intrinsic and extrinsic factors on activity during this critical life stage. We used hourly GPS data, collected from 66 Antarctic fur seal pups from birth until moulting, to investigate the explanatory power of multiple individual-based and environmental variables on activity levels. Pups were sampled from two nearby breeding colonies of contrasting density during two subsequent years, and a two-state hidden Markov model was used to identify modalities in their movement behaviour, specifically 'active' and 'inactive' states. We found that movement was typified by central place exploration, with active movement away from and subsequent return to a location of inactivity. The probability of such directed exploration was unaffected by several factors known to influence marine mammal movement including sex, body condition, and temperature. Compared to pups born at the high-density colony, pups at low-density were more active, increased their activity with age, and transitioned earlier into the tussock grass, which offers protection from predators and extreme weather. Our study illustrates the importance of extrinsic factors, such as colony of birth, to early-life activity patterns and highlights the adaptive potential of movement.

Evidence for an Allee effect in a declining fur seal population.

Allee effects play an important role in the dynamics of many populations and can increase the risk of local extinction. However, some authors have questioned the weight of evidence for Allee effects in wild populations. We therefore exploited a natural experiment provided by two adjacent breeding colonies of contrasting density to investigate the potential for Allee effects in an Antarctic fur seal (Arctocephalus gazella) population that is declining in response to climate change-induced reductions in food availability. Biometric time-series data were collected from 25 pups per colony during two consecutive breeding seasons, the first of which was among the worst on record in terms of breeding female numbers, pup birth weights and foraging trip durations. In previous decades when population densities were higher, pup mortality was consistently negatively density dependent, with rates of trauma and starvation scaling positively with density. However, we found the opposite, with higher pup mortality at low density and the majority of deaths attributable to predation. In parallel, body condition was depressed at low density, particularly in the poor-quality season. Our findings shed light on Allee effects in wild populations and highlight a potential emerging role of predators in the ongoing decline of a pinniped species.

Social Media and Ophthalmology: Perspectives of Patients and Ophthalmologists.

Recent research has analyzed how patients use social media, but little information exists evaluating how patients utilize social media in the perioperative period or how ophthalmologists and eye institutions integrate social media into their practices. This observational study aimed to examine (1) how patients interact on social media when undergoing LASIK and (2) how ophthalmologists and (3) eye institutions utilize social media accounts. We analyzed 2592 Instagram posts between August 2016 and April 2017 on a related hashtag (#lasiksurgery). Content was coded based on time frame of the post in relation to the procedure, references to return to work/activity, post-surgical photographs, mention of the surgical institution, tone, and complaints regarding the procedure. Twitter and Instagram accounts for 30 ophthalmologists and eye institutes were also located. The 20 most recent posts were categorized by message type and topic (physicians, patients, education, conference, etc.). Patients using the hashtag posted photographs (92%), had a positive tone (88%), referenced the clinic where they were treated (62%), and posted during the day of the procedure (44%). Ophthalmologists' personal tweets focused on research conferences (35%), personal topics (25%), and the accomplishments of other physicians (21%). Eye institutions generally posted content relating to institutional promotion (22%), physician accomplishments (20%), and research publications (19%). Similar to other medical specialties, ophthalmology has a meaningful presence on both Twitter and Instagram. While LASIK patients tend to comment on their renewed vision and return to activity, ophthalmologists post to promote their research and accomplishments.

Etiology and treatment outcomes of persistent postoperative inflammation in primary resident-performed cataract surgeries at a large tertiary care public hospital.

PURPOSE: To determine the risk factors, intraoperative and postoperative complications, therapeutic interventions, and visual outcomes for persistent postoperative inflammation in primary resident-performed cataract surgeries. SETTING: Ben Taub General Hospital, Houston, Texas, USA. DESIGN: Retrospective case series. METHODS: Primary resident-performed cataract surgeries from January 2012 to June 2015 were analyzed for persistent postoperative inflammation, defined as persistent anterior chamber inflammatory reaction after a standard 1-month topical corticosteroid and nonsteroidal antiinflammatory drug (NSAID) drops taper. Preoperative characteristics, operative complications, therapeutic modalities, and duration of therapy were analyzed. The primary outcome measures were duration of corticosteroid and NSAID therapy, treatment modalities, and postoperative visual outcomes at the 1-month postoperative visit. RESULTS: The study assessed 1290 primary resident-performed cataract surgeries. Persistent postoperative inflammation occurred in 82 eyes (6.6%). The presumed etiology was classified as idiopathic persistent postoperative inflammation, nonadherence to topical therapy, and complicated cataract surgery. Patients with persistent postoperative inflammation were more likely of African American descent, had hypertension, or used aspirin, anticoagulants, or prostaglandins (P = .019, P = .027, P = .028, P = .020, respectively). The complicated cataract subgroup required a longer duration of therapy (P = .021) and was the only subgroup to require injections or systemic corticosteroids. There was no significant difference in postoperative corrected distance visual acuity (CDVA) when comparing patients with persistent postoperative inflammation with those without inflammation or between the subgroups. CONCLUSIONS: The idiopathic and nonadherent subgroups were successfully treated with topical antiinflammatory therapy; the complicated subgroup required longer duration and multiple modalities of treatment. Visual outcomes were comparable to the general cataract population with no differences in postoperative CDVA.

Evolving risk factors and antibiotic sensitivity patterns for microbial keratitis at a large county hospital.

Purpose: To identify the risk factors, causative organisms, antimicrobial susceptibility and outcomes of microbial keratitis in a large county hospital in Houston, Texas.Design: Case series. METHODS: Setting: A large county hospital in Houston, Texas. STUDY POPULATION: Patients with known diagnosis of microbial keratitis from January 2011 to May 2015. OBSERVATION PROCEDURE: Retrospective chart review. MAIN OUTCOMES: Epidemiology, risk factors, outcomes and antibiotic susceptibility of microbial keratitis. RESULTS: The most commonly identified risk factors were contact lens use (34.4%), ocular trauma (26.3%), diabetes mellitus (16.7%), ocular surgery (13.5%), ocular surface diseases (11.5%), previous keratitis (10.4%), glaucoma (6.3%), cocaine use (5.2%) and HIV-positive status (4.2%). Eyes with positive cultures (61.5%) were associated with worse visual outcomes (p=0.019) and a higher number of follow-up visits (p=0.007) than eyes with negative cultures (38.5%). Corneal perforation was the most common complication (11.5%). Gram-negative organisms (21.9%) were all susceptible to ceftazidime, tobramycin and fluoroquinolones. Gram-positive organisms (33.3%) had worse outcomes than Gram-negative organisms (21.9%) and exhibited a wide spectrum of antibiotic resistance, but all were susceptible to vancomycin. Twenty-seven per cent of the coagulase-negative Staphylococci were resistant to fluoroquinolones. CONCLUSION: This study identified a recent shift in risk factors and antibiotic resistance patterns in microbial keratitis at a County Hospital in Houston, Texas. In our patient population, fluoroquinolone monotherapy is not recommended for severe corneal ulcers. On the basis of these results, vancomycin and tobramycin should be used for empirical therapy until microbial identity and sensitivity results are available.

Outcomes and complication rates of primary resident-performed cataract surgeries at a large tertiary-care county hospital.

PURPOSE: To identify the preoperative risk factors, intraoperative events, and postoperative complications increasing the risk for poor visual outcomes in resident-performed cataract surgeries at a tertiary-care county hospital. SETTING: Ben Taub General Hospital, Houston, Texas, USA. DESIGN: Retrospective case series. METHODS: Resident-performed cataract surgeries were analyzed for risk factors, comorbidities, and intraoperative and postoperative complications. The main outcome measures were preoperative and postoperative uncorrected distance visual acuity and corrected distance visual acuity (CDVA), which were correlated with preoperative demographics, intraoperative and postoperative events, and resident training level. The data were subdivided into cases without events and cases with events to determine which complications led to poor visual outcomes. RESULTS: The study analyzed 1290 resident-performed cataract surgeries. The mean visual acuity improved significantly after surgery in all patients (P < .001), with 80.5% of patients without complications and 70.7% with complications attaining a CDVA of 20/40 or better (P < .002). Poor visual outcomes were associated with α-antagonist use (P = .043) and pseudoexfoliation syndrome (P = .001). The most common intraoperative complications were vitreous loss (6.7%) and posterior capsule tear (7.0%). The mean postoperative visual acuity did not vary by trainee year, and the rate of dropped nucleus during surgery declined as residents progressed in training (P < .05). All other complication rates were similar between levels of training. CONCLUSION: Despite more complicated cataracts and advanced comorbidities, primary resident-performed cataract surgery in a tertiary-care county hospital system achieved visual outcomes and complication rates similar to those found in other training hospitals.

What could you do with 400 years of biological history on african americans? Evaluating the potential scientific benefit of systematic studies of dental and skeletal materials on African Americans from the 17th through 20th centuries.

OBJECTIVES: How important is it to be able to reconstruct the lives of a highly diverse, historically recent macroethnic group over the course of 400 years? How many insights into human evolutionary biology and disease susceptibilities could be gained, even with this relatively recent window into the past? In this article, we explore the potential ramifications of a newly constructed dataset of Four Centuries of African American Biological Variation (4Cs). METHODS: This article provides initial lists of digitized variables formatted as SQL tables for the 17th and 18th century samples and for the 19th and 20th century samples. RESULTS: This database is dynamic and new information is added yearly. The database provides novel opportunities for significant insights into the past biological history of this group and three case study applications are detailed for comparative computational systems biology studies of (1) hypertension, (2) the oral microbiome, and (3) mental health disorders. CONCLUSIONS: The 4Cs dataset is ideal for interdisciplinary "next generation" science research and these data represent a unique step toward the accumulation of historically contextualized Big Data on an underrepresented group known to have experienced differential survival over time. Am. J. Hum. Biol. 28:510-513, 2016. © 2016 The Authors American Journal of Human Biology Published byWiley Periodicals, Inc.