Search

BACKGROUND: The number of International Medical Graduate (IMG) applicants to residency programs has increased steadily over the past decade. Despite high motivation and significant medical knowledge, differences in training and cultural expectations can create knowledge gaps and influence how IMGs relate to patients and staff. This contributes to increased opportunities for medical errors, patient dissatisfaction, and frustration among colleagues. DESCRIPTION: To improve this transition we introduced a required, 2-week precourse for IMGs entering our program. The curriculum focused around the Accreditation Council for Graduate Medical Education core competencies. EVALUATION: Participants reported knowledge gains and rated favorably didactic sessions and small-group activities. Program directors and other key stakeholders reported positive experiences with the precourse, especially the reduction in transition stress and missed work time in July. CONCLUSION: An intensive precourse for IMGs can attenuate transition stress and increase knowledge of core medical skills and competencies. [ABSTRACT FROM AUTHOR]

Buruli ulcer is a chronic ulcerative disease of the skin and subcutaneous tissues caused by infection with Mycobacterium ulcerans. Although Australian possums are known to be susceptible to Buruli ulcer, many aspects of the disease in possums, including welfare impacts, remain largely unreported. Severe clinical Buruli ulcer was identified in four common ringtail possums (Pseudocheirus peregrinus) from Melbourne, Victoria. All four possums were euthanased due to the presence of deep ulcerative lesions on paws, with extensive tissue necrosis that exposed bones and tendons in three cases. Histologically, there was severe ulcerative necrotising pyogranulomatous dermatitis, panniculitis and myositis, with intralesional acid‐fast bacteria. M. ulcerans was detected by real‐time PCR in all swabs, tissues and faeces collected from all four cases. Buruli ulcer may be an important and under‐recognised cause of poor possum welfare in endemic areas. The physical impacts of the severe cutaneous lesions, especially those extending to underlying bones and joints, would have directly impaired the mobility of these possums, affecting navigation of their natural environments and expression of natural behaviours including foraging and socialising. Systemic distribution of M. ulcerans throughout all major internal organs, as observed here, may further impact the health and fitness of infected possums. Faecal shedding of M. ulcerans in all four cases supports the role of possums as zoonotic reservoirs. Further research is needed to investigate the epidemiology, pathogenesis and welfare impacts of Buruli ulcer in possums and to inform the design of interventions that may protect their health and welfare. [ABSTRACT FROM AUTHOR]

Reconstructing the evolutionary origins of Mycobacterium tuberculosis, the causative agent of human tuberculosis, has helped identify bacterial factors that have led to the tubercle bacillus becoming such a formidable human pathogen. Here we report the discovery and detailed characterization of an exceedingly slow growing mycobacterium that is closely related to M. tuberculosis for which we have proposed the species name Mycobacterium spongiae sp. nov., (strain ID: FSD4b-SM). The bacterium was isolated from a marine sponge, taken from the waters of the Great Barrier Reef in Queensland, Australia. Comparative genomics revealed that, after the opportunistic human pathogen Mycobacterium decipiens, M. spongiae is the most closely related species to the M. tuberculosis complex reported to date, with 80% shared average nucleotide identity and extensive conservation of key M. tuberculosis virulence factors, including intact ESX secretion systems and associated effectors. Proteomic and lipidomic analyses showed that these conserved systems are functional in FSD4b-SM, but that it also produces cell wall lipids not previously reported in mycobacteria. We investigated the virulence potential of FSD4b-SM in mice and found that, while the bacteria persist in lungs for 56 days after intranasal infection, no overt pathology was detected. The similarities with M. tuberculosis, together with its lack of virulence, motivated us to investigate the potential of FSD4b-SM as a vaccine strain and as a genetic donor of the ESX-1 genetic locus to improve BCG immunogenicity. However, neither of these approaches resulted in superior protection against M. tuberculosis challenge compared to BCG vaccination alone. The discovery of M. spongiae adds to our understanding of the emergence of the M. tuberculosis complex and it will be another useful resource to refine our understanding of the factors that shaped the evolution and pathogenesis of M. tuberculosis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Pidot et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

A Mycobacterium ulcerans human challenge model has the potential to fundamentally advance our understanding of early human immune responses to infection, while rapidly evaluating vaccines and other therapeutic interventions. Here, using a murine tail infection model, we tested a very well-characterized working cell bank of the proposed challenge isolate M. ulcerans JKD8049 in naïve and Mycobacterium bovis bacille Calmette-Guérin (BCG)-vaccinated BALB/c mice. All 10 naïve mice were successfully infected with 20 colony-forming units (CFU) of M. ulcerans [95% confidence interval (CI) 17-22 CFU] with a mean time to visible lesion of 86 days (95% CI 79-92 days). In the 10 vaccinated mice, there was a significant delay in the mean time to lesion compared to the naïve controls of 24 days ( P = 0.0003), but all mice eventually developed ulcerative lesions. This study informs a future human infection model by demonstrating the successful application of the challenge agent in this in vivo model and highlights both the promise and the problems with trying to induce protective immunity against M. ulcerans ., Importance: In preparation for its proposed use in a controlled human infection model (CHIM), this study reports the successful infection of BALB/c mice using a carefully characterized, low-dose inoculum of Mycobacterium ulcerans JKD8049 (our proposed CHIM strain). We also demonstrate that Mycobacterium bovis bacille Calmette-Guérin delays the onset of disease but cannot alter the course of illness once a lesion becomes apparent. We also validate the findings of previous low-dose challenges that used less accurate methods to determine the inoculum, but our presented methodology is practical, accurate, and anticipated to be reproducible., Competing Interests: The authors declare no conflict of interest.

Critical scientific questions remain regarding infection with Mycobacterium ulcerans, the organism responsible for the neglected tropical disease, Buruli ulcer (BU). A controlled human infection model has the potential to accelerate our knowledge of the immunological correlates of disease, to test prophylactic interventions and novel therapeutics. Here we present microbiological evidence supporting M. ulcerans JKD8049 as a suitable human challenge strain. This non-genetically modified Australian isolate is susceptible to clinically relevant antibiotics, can be cultured in animal-free and surfactant-free media, can be enumerated for precise dosing, and has stable viability following cryopreservation. Infectious challenge of humans with JKD8049 is anticipated to imitate natural infection, as M. ulcerans JKD8049 is genetically stable following in vitro passage and produces the key virulence factor, mycolactone. Also reported are considerations for the manufacture, storage, and administration of M. ulcerans JKD8049 for controlled human infection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Muhi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Buruli ulcer, a chronic subcutaneous infection caused by Mycobacterium ulcerans, is increasing in prevalence in southeastern Australia. Possums are a local wildlife reservoir for M. ulcerans and, although mosquitoes have been implicated in transmission, it remains unclear how humans acquire infection. We conducted extensive field survey analyses of M. ulcerans prevalence among mosquitoes in the Mornington Peninsula region of southeastern Australia. PCR screening of trapped mosquitoes revealed a significant association between M. ulcerans and Aedes notoscriptus. Spatial scanning statistics revealed overlap between clusters of M. ulcerans-positive Ae. notoscriptus, M. ulcerans-positive possum excreta and Buruli ulcer cases, and metabarcoding analyses showed individual mosquitoes had fed on humans and possums. Bacterial genomic analysis confirmed shared single-nucleotide-polymorphism profiles for M. ulcerans detected in mosquitoes, possum excreta and humans. These findings indicate Ae. notoscriptus probably transmit M. ulcerans in southeastern Australia and highlight mosquito control as a Buruli ulcer prevention measure., (© 2024. The Author(s).)

The Daedalus ultrafast x-ray imager is the latest generation in Sandia's hybrid CMOS detector family. With three frames along an identical line of sight, 1 ns minimum integration time, a higher full well than Icarus, and added features, Daedalus brings exciting new capabilities to diagnostic applications in inertial confinement fusion and high energy density science. In this work, we present measurements of time response, dynamic range, spatial uniformity, pixel cross-talk, and absolute x-ray sensitivity using pulsed optical and x-ray sources. We report a measured 1.5 Me- full well, pixel sensitivity at 9.58 × 10-7 V/e-, and an estimate of spatial uniformity at ∼5% across the sensor array., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

Introduction: Mycobacterium ulcerans (MU) causes Buruli ulcer (Buruli), a geographically restricted infection that can result in skin loss, contracture and permanent scarring. Lesion-location maps compiled from more than 640 cases in south eastern Australia suggest biting insects are likely involved in transmission, but it is unclear whether MU is brought by insects to humans or if MU is already on the skin and inoculation is an opportunistic event that need not be insect dependent., Methods: We validated a PCR swab detection assay and defined its dynamic range using laboratory cultured M. ulcerans and fresh pigskin. We invited volunteers in Buruli-endemic and non-endemic areas to sample their skin surfaces with self-collected skin swabs tested by IS2404 quantitative PCR., Results: Pigskin validation experiments established a limit-of-detection of 0.06 CFU/cm2 at a qPCR cycle threshold (Ct) of 35. Fifty-seven volunteers returned their self-collected kits of 4 swabs (bilateral ankles, calves, wrists, forearms), 10 from control areas and 47 from endemic areas. Collection was timed to coincide with the known peak-transmission period of Buruli. All swabs from human volunteers tested negative (Ct ≥35)., Conclusions: M. ulcerans was not detected on the skin of humans from highly Buruli endemic areas., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Velink et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Hybrid CMOS (hCMOS) x-ray framing cameras are a new and powerful detector option for experiments in the fields of Inertial Confinement Fusion (ICF) and High Energy Density Physics (HEDP). These digital cameras capture multiple images along a single line-of-sight with a time resolution as short as 1.5 ns and with high quantum efficiency. To manage the high data rate, an image sequence is acquired in a short burst of time and subsequently read out on a much longer time scale. The technology is well suited for operating in high radiation environments, including fusion ignition experiments. Diagnostics using hCMOS cameras are now deployed in experiments on major laser and pulsed-power ICF facilities around the world. Continued advances in microelectronics technologies will enable faster and more capable detectors well into the future. This paper reviews this detector technology with a focus on application to ICF and HEDP experiments., (© 2023 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).)

We report on progress implementing and testing cryogenically cooled platforms for Magnetized Liner Inertial Fusion (MagLIF) experiments. Two cryogenically cooled experimental platforms were developed: an integrated platform fielded on the Z pulsed power generator that combines magnetization, laser preheat, and pulsed-power-driven fuel compression and a laser-only platform in a separate chamber that enables measurements of the laser preheat energy using shadowgraphy measurements. The laser-only experiments suggest that ∼89% ± 10% of the incident energy is coupled to the fuel in cooled targets across the energy range tested, significantly higher than previous warm experiments that achieved at most 67% coupling and in line with simulation predictions. The laser preheat configuration was applied to a cryogenically cooled integrated experiment that used a novel cryostat configuration that cooled the MagLIF liner from both ends. The integrated experiment, z3576, coupled 2.32 ± 0.25 kJ preheat energy to the fuel, the highest to-date, demonstrated excellent temperature control and nominal current delivery, and produced one of the highest pressure stagnations as determined by a Bayesian analysis of the data., (© 2023 Author(s). Published under an exclusive license by AIP Publishing.)

Background: Buruli ulcer (BU) is a neglected tropical disease caused by infection of subcutaneous tissue with Mycobacterium ulcerans . BU is commonly reported across rural regions of Central and West Africa but has been increasing dramatically in temperate southeast Australia around the major metropolitan city of Melbourne, with most disease transmission occurring in the summer months. Previous research has shown that Australian native possums are reservoirs of M. ulcerans and that they shed the bacteria in their fecal material (excreta). Field surveys show that locales where possums harbor M. ulcerans overlap with human cases of BU, raising the possibility of using possum excreta surveys to predict the risk of disease occurrence in humans., Methods: We thus established a highly structured 12 month possum excreta surveillance program across an area of 350 km 2 in the Mornington Peninsula area 70 km south of Melbourne, Australia. The primary objective of our study was to assess using statistical modeling if M. ulcerans surveillance of possum excreta provided useful information for predicting future human BU case locations., Results: Over two sampling campaigns in summer and winter, we collected 2,282 possum excreta specimens of which 11% were PCR positive for M. ulcerans -specific DNA. Using the spatial scanning statistical tool SaTScan , we observed non-random, co-correlated clustering of both M. ulcerans positive possum excreta and human BU cases. We next trained a statistical model with the Mornington Peninsula excreta survey data to predict the future likelihood of human BU cases occurring in the region. By observing where human BU cases subsequently occurred, we show that the excreta model performance was superior to a null model trained using the previous year's human BU case incidence data (AUC 0.66 vs 0.55). We then used data unseen by the excreta-informed model from a new survey of 661 possum excreta specimens in Geelong, a geographically separate BU endemic area to the southwest of Melbourne, to prospectively predict the location of human BU cases in that region. As for the Mornington Peninsula, the excreta-based BU prediction model outperformed the null model (AUC 0.75 vs 0.50) and pinpointed specific locations in Geelong where interventions could be deployed to interrupt disease spread., Conclusions: This study highlights the One Health nature of BU by confirming a quantitative relationship between possum excreta shedding of M. ulcerans and humans developing BU. The excreta survey-informed modeling we have described will be a powerful tool for the efficient targeting of public health responses to stop BU., Funding: This research was supported by the National Health and Medical Research Council of Australia and the Victorian Government Department of Health (GNT1152807 and GNT1196396)., Competing Interests: KV, AB, JP, AV, JW, KB, MD, VB, JF, ET, PJ, SW, NG, TS No competing interests declared, (© 2023, Vandelannoote, Buultjens et al.)

This study evaluates the generality of self-control theory with a previously untested cultural group rarely studied by criminologists, the Deaf community. Survey data ( n  = 428) from participants attending a university that houses a college for the Deaf and hard-of-hearing were compared with a sample of "hearing" students. The findings support Gottfredson and Hirschi's cultural invariance thesis as self-control was consistently able to predict a wide range of rule-breaking behaviors among the culturally distinct groups examined. However, several unexpected results challenge the parental management thesis. In particular, exposure to effective parenting techniques was a significant contributor to variations in self-control for the hearing, but not the Deaf sample. Additionally, self-control did not fully mediate the relationship between child-rearing experiences and norm violating behaviors for the Deaf sample. Implications of these findings are discussed.

Diagnostics in high energy density physics, shock physics, and related fields are primarily driven by a need to record rapidly time-evolving signals in single-shot events. These measurements are often limited by channel count and signal degradation issues on cable links between the detector and digitizer. We present the Ultrafast Pixel Array Camera (UPAC), a compact and flexible detector readout system with 32 waveform-recording channels at up to 10 Gsample/s and 1.8 GHz analog bandwidth. The compact footprint allows the UPAC to be directly embedded in the detector environment. A key enabling technology is the PSEC4A chip, an eight-channel switch-capacitor array sampling device with up to 1056 samples/channel. The UPAC system includes a high-density input connector that can plug directly into an application-specific detector board, programmable control, and serial readout, with less than 5 W of power consumption in full operation. We present the UPAC design and characterization, including a measured timing resolution of ∼20 ps or better on acquisitions of sub-nanosecond pulses with minimal system calibrations. Example applications of the UPAC are also shown to demonstrate operation of a solid-state streak camera, an ultrafast imaging array, and a neutron time-of-flight spectrometer.

Objectives: The physical exam component of a periodic health visit in the elderly has not been considered useful. Standard Medicare Wellness visits require no physical exam beyond blood pressure and most physicians perform limited exams during these visits. The objective of this study was to test the feasibility, potential benefit, and costs of performing a screening ultrasound (US) exam during Medicare Wellness visits., Methods: A physician examiner at an academic internal medicine primary care clinic performed a screening US exam targeting important abnormalities of patients 65-85 years old during a Medicare Wellness visit. The primary care physician (PCP) recorded the follow-up items for each abnormality identified by the US examiner and assessed the benefit of each abnormality for the participant. Abnormality benefit, net exam benefit per participant, follow-up items and costs, participant survey results, and exam duration were assessed., Results: Participants numbered 108. Total abnormalities numbered 283 and new diagnoses were 172. Positive benefit scores were assigned to 38.8%, neutral (zero) scores to 59.4%, and negative benefit scores to 1.8% of abnormalities. Net benefit scores per participant were positive in 63.9%, 0 in 34.3%, and negative in 1.8%. Follow-up items were infrequent resulting in 76% of participants without follow-up cost. Participant survey showed excellent acceptance of the exam., Conclusions: The US screening exam identified frequent abnormalities in Medicare Wellness patients. The assessed benefits were rarely negative and often mild to moderately positive, with important new chronic conditions identified. Follow-up costs were low when the PCPs were also US experts., (© 2021 American Institute of Ultrasound in Medicine.)

Nontuberculosis mycobacterial (NTM) infections are increasing in prevalence across the world. In many cases, treatment options for these infections are limited. However, there has been progress in recent years in the development of new antimycobacterial drugs. Here, we investigate the in vitro activity of SPR719, a novel aminobenzimidazole antibiotic and the active form of the clinical-stage compound, SPR720, against several isolates of Mycobacterium ulcerans, Mycobacterium marinum and Mycobacterium chimaera. We show that SPR719 is active against these NTM species with a MIC range of 0.125-4 μg/ml and that this compares favorably with the commonly utilized antimycobacterial antibiotics, rifampicin and clarithromycin. Our findings suggest that SPR720 should be further evaluated for the treatment of NTM infections., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests: Troy Lister is a current employee of Spero Therapeutics. Timothy P Stinear is a member of the editorial board of PLoS Neglected Tropical Diseases.

Mycobacterium kansasii can cause serious pulmonary disease. It belongs to a group of closely-related species of non-tuberculous mycobacteria known as the M. kansasii complex (MKC). Here, we report a population genomics analysis of 358 MKC isolates from worldwide water and clinical sources. We find that recombination, likely mediated by distributive conjugative transfer, has contributed to speciation and on-going diversification of the MKC. Our analyses support municipal water as a main source of MKC infections. Furthermore, nearly 80% of the MKC infections are due to closely-related M. kansasii strains, forming a main cluster that apparently originated in the 1900s and subsequently expanded globally. Bioinformatic analyses indicate that several genes involved in metabolism (e.g., maintenance of the methylcitrate cycle), ESX-I secretion, metal ion homeostasis and cell surface remodelling may have contributed to M. kansasii's success and its ongoing adaptation to the human host.

Hybrid CMOS multi-frame imagers with exposure times down to ∼2 ns have made significant impacts in high energy density physics and inertial confinement fusion research. The detector thickness is a key parameter in both detector quantum efficiency and temporal response. The Icarus hybrid CMOS imager has been fabricated with Si detector thicknesses of 8, 25, and 100 µm. The temporal response of imaging sensors with exposure time down to 2 ns has been examined and compared to directly measured photodiode current. The 100-μm thick variant displays extended features related to charge carrier collection and is more susceptible to field collapse. We also demonstrate charge collection time effects on spatial response.

We present experimental results from the first systematic study of performance scaling with drive parameters for a magnetoinertial fusion concept. In magnetized liner inertial fusion experiments, the burn-averaged ion temperature doubles to 3.1 keV and the primary deuterium-deuterium neutron yield increases by more than an order of magnitude to 1.1×10^{13} (2 kJ deuterium-tritium equivalent) through a simultaneous increase in the applied magnetic field (from 10.4 to 15.9 T), laser preheat energy (from 0.46 to 1.2 kJ), and current coupling (from 16 to 20 MA). Individual parametric scans of the initial magnetic field and laser preheat energy show the expected trends, demonstrating the importance of magnetic insulation and the impact of the Nernst effect for this concept. A drive-current scan shows that present experiments operate close to the point where implosion stability is a limiting factor in performance, demonstrating the need to raise fuel pressure as drive current is increased. Simulations that capture these experimental trends indicate that another order of magnitude increase in yield on the Z facility is possible with additional increases of input parameters.

In the United States, youth aged 13-24 comprised approximately 21% of new HIV infections in 2017; 13% of these infections occurred among women, the majority of whom (86%) acquired HIV through heterosexual contact (Centers for Disease Control and Prevention. 2019a. HIV and youth . Retrieved from https://www.cdc.gov/hiv/group/age/youth/index.html, Centers for Disease Control and Prevention. 2019b. HIV among women . Retrieved from https://www.cdc.gov/hiv/group/gender/women/index.html). We fit and validated a developmentally appropriate empirical model of Connell's Theory of Gender and Power (Connell, R. W. 1987. Gender and power: Society, the person and sexual politics . Stanford, CA: Stanford University Press, Connell, R. W. 2013. Gender and power: Society, the person and sexual politics . Hoboken, NJ: John Wiley & Sons) in a sample of young women and assessed whether gendered powerlessness reflected a multidimensional higher-order latent factor, as the theory implies. Anonymous computer-assisted interviews were administered to at-risk, sexually active young women ( N  = 1,101). Factor analyses and structural equation modeling were used to determine the dimensionality of gendered powerlessness. Associations with condom use were examined to validate the model. We fit a three-component model of gendered powerlessness, but not a higher-order latent factor. We observed that high scores on two dimensions of gendered powerlessness - cathexis and sexual division of power - were associated with lower likelihood of condom use. Our three-component model helps elucidate the role that components of gendered powerlessness play in young women's health behaviors and underscores the need for measures tailored to young women at high risk of contracting HIV.

Introduction. The SARS-CoV-2 pandemic of 2020 has resulted in unparalleled requirements for RNA extraction kits and enzymes required for virus detection, leading to global shortages. This has necessitated the exploration of alternative diagnostic options to alleviate supply chain issues. Aim. To establish and validate a reverse transcription loop-mediated isothermal amplification (RT- LAMP) assay for the detection of SARS-CoV-2 from nasopharyngeal swabs. Methodology. We used a commercial RT-LAMP mastermix from OptiGene in combination with a primer set designed to detect the CDC N1 region of the SARS-CoV-2 nucleocapsid (N) gene. A single-tube, single-step fluorescence assay was implemented whereby 1 µl of universal transport medium (UTM) directly from a nasopharyngeal swab could be used as template, bypassing the requirement for RNA purification. Amplification and detection could be conducted in any thermocycler capable of holding 65 °C for 30 min and measure fluorescence in the FAM channel at 1 min intervals. Results. Assay evaluation by assessment of 157 clinical specimens previously screened by E-gene RT-qPCR revealed assay sensitivity and specificity of 87 and 100%, respectively. Results were fast, with an average time-to-positive (Tp) for 93 clinical samples of 14 min (sd±7 min). Using dilutions of SARS-CoV-2 virus spiked into UTM, we also evaluated assay performance against FDA guidelines for implementation of emergency-use diagnostics and established a limit-of-detection of 54 Tissue Culture Infectious Dose 50 per ml (TCID 50 ml -1 ), with satisfactory assay sensitivity and specificity. A comparison of 20 clinical specimens between four laboratories showed excellent interlaboratory concordance; performing equally well on three different, commonly used thermocyclers, pointing to the robustness of the assay. Conclusion. With a simplified workflow, The N1 gene Single Tube Optigene LAMP assay (N1-STOP-LAMP) is a powerful, scalable option for specific and rapid detection of SARS-CoV-2 and an additional resource in the diagnostic armamentarium against COVID-19.

Background: Mycobacterium ulcerans is the causative agent of a debilitating skin and soft tissue infection known as Buruli ulcer (BU). There is no vaccine against BU. The purpose of this study was to investigate the vaccine potential of two previously described immunogenic M. ulcerans proteins, MUL_3720 and Hsp18, using a mouse tail infection model of BU., Methods: Recombinant versions of the two proteins were each electrostatically coupled with a previously described lipopeptide adjuvant. Seven C57BL/6 and seven BALB/c mice were vaccinated and boosted with each of the formulations. Vaccinated mice were then challenged with M. ulcerans via subcutaneous tail inoculation. Vaccine performance was assessed by time-to-ulceration compared to unvaccinated mice., Results: The MUL_3720 and Hsp18 vaccines induced high titres of antigen-specific antibodies that were predominately subtype IgG 1 . However, all mice developed ulcers by day-40 post- M. ulcerans challenge. No significant difference was observed in the time-to-onset of ulceration between the experimental vaccine groups and unvaccinated animals., Conclusions: These data align with previous vaccine experiments using Hsp18 and MUL_3720 that indicated these proteins may not be appropriate vaccine antigens. This work highlights the need to explore alternative vaccine targets and different approaches to understand the role antibodies might play in controlling BU ., Competing Interests: Timothy Stinear is an Academic Editor for PeerJ., (©2020 Mangas et al.)

Tracking long-term environmental change is important, particularly for freshwater ecosystems, often with high rates of decline. Waterbirds are key indicators of freshwater ecosystem change, with groups reflecting food availability (e.g. piscivores and fish). We store waterbird (species abundance, numbers of nests and broods) and wetland area data from aerial surveys of waterbirds across Australia, mostly at the species' level (∼100 species) from three aerial survey programs: Eastern Australian Waterbird Survey, National Survey and Murray-Darling Basin wetlands. Across eastern Australia, we survey up to 2,000 wetlands annually (October, since 1983), along 10 survey bands (30 km wide), east to west across about one third of Australia. In 2008, we surveyed 4,858 wetlands across Australia and each year (since 2010) we survey the major wetlands in the Murray-Darling Basin. These data inform regulation of hunting seasons in Victoria and South Australia, Game bird culling in NSW, State of the Environment Reporting, environmental assessments, river and wetland management, the status of individual species and identification of high conservation sites.

The genus Nocardia contains >50 human pathogenic species that cause a range of illnesses from skin and soft tissue infections to lung and brain infections. However, despite their membership in the most prominent family of secondary metabolite producers (the Actinomycetes), the ability of Nocardia species, especially those that cause human infections, to produce secondary metabolites has not been as well studied. Using genome mining, we have investigated cryptic secondary metabolite biosynthesis gene clusters from Nocardia species and identified a conserved locus within human pathogenic strains of Nocardia brasiliensis and Nocardia vulneris . Direct capture and heterologous expression in a Streptomyces host activated the biosynthetic locus, revealing it to be the source of the brasiliquinones, benz[ a ]anthraquinone antibiotics whose biosynthetic pathway has remained hidden for over two decades, until now. Our findings highlight these hitherto neglected human pathogenic Nocardia as a source of diverse and important natural products.

Ultrafast x-ray imagers developed at Sandia National Laboratories are a transformative diagnostic tool in inertial confinement fusion and high energy density physics experiments. The nanosecond time scales on which these devices operate are a regime with little precedent, and applicable characterization procedures are still developing. This paper presents pulsed x-ray characterization of the Icarus imager under a variety of illumination levels and timing modes. Results are presented for linearity of response, absolute sensitivity, variation of response with gate width, and image quality.

The neglected tropical disease Buruli ulcer (BU) is an infection of subcutaneous tissue with Mycobacterium ulcerans There is no effective vaccine. Here, we assessed an experimental prime-boost vaccine in a low-dose murine tail infection model. We used the enoyl reductase (ER) domain of the M. ulcerans mycolactone polyketide synthases electrostatically coupled with a previously described Toll-like receptor 2 (TLR-2) agonist-based lipopeptide adjuvant, R 4 Pam 2 Cys. Mice were vaccinated and then challenged via tail inoculation with 14 to 20 CFU of a bioluminescent strain of M. ulcerans Mice receiving either the experimental ER vaccine or Mycobacterium bovis bacillus Calmette-Guérin (BCG) were equally protected, with both groups faring significantly better than nonvaccinated animals ( P <  0.05). To explore potential correlates of protection, a suite of 29 immune parameters were assessed in the mice at the end of the experimental period. Multivariate statistical approaches were used to interrogate the immune response data to develop disease-prognostic models. High levels of interleukin 2 (IL-2) and low gamma interferon (IFN-γ) produced in the spleen best predicted control of infection across all vaccine groups. Univariate logistic regression revealed vaccine-specific profiles of protection. High titers of ER-specific IgG serum antibodies together with IL-2 and IL-4 in the draining lymph node (DLN) were associated with protection induced by the ER vaccine. In contrast, high titers of IL-6, tumor necrosis factor alpha (TNF-α), IFN-γ, and IL-10 in the DLN and low IFN-γ titers in the spleen were associated with protection following BCG vaccination. This study suggests that an effective BU vaccine must induce localized, tissue-specific immune profiles with controlled inflammatory responses at the site of infection., (Copyright © 2020 American Society for Microbiology.)

Fast x-ray detectors are critical tools in pulsed power and fusion applications, where detector impulse response of a nanosecond or better is often required. Semiconductor detectors can create fast, sensitive devices with extensive operational flexibility. There is typically a trade-off between detector sensitivity and speed, but higher atomic number absorbers can increase hard x-ray absorption without increasing the charge collection time, provided carriers achieve high velocity. This paper presents x-ray pulse characterization conducted at the Advanced Photon Source of x-ray absorption efficiency and temporal impulse response of current-mode semiconductor x-ray detectors composed of Si, GaAs, and CdTe.

Buruli ulcer (BU) is a neglected tropical disease caused by infection with Mycobacterium ulcerans . Unclear transmission, no available vaccine, and suboptimal treatment regimens hamper the control of this disease. Carefully designed preclinical research is needed to address these shortcomings. In vivo imaging (IVIS ® , Perkin Elmer, Waltham, MA) of infection is an emerging tool that permits monitoring of disease progression and reduces the need to using large numbers of mice at different time-points during the experiment, as individual mice can be imaged at multiple time-points. We aimed to further describe the use of in vivo imaging (IVIS) in BU. We studied the detection of M. ulcerans in experimentally infected BALB/c mouse tails and the subsequent histopathology and immune response in this pilot study. IVIS-monitoring was performed weekly in ten infected BALB/c mice to measure light emitted as a proxy for bacterial load. Nine of 10 (90%) BALB/c mice infected subcutaneously with 3.3 × 10 5 M. ulcerans JKD8049 (containing pMV306 hsp16+luxG13) exhibited light emission from the site of infection, indicating M. ulcerans growth in vivo, whereas only five of 10 (50%) animals developed clinical signs of the disease. Specific antibody titers were detected within 2 weeks of the infection. Interferon (IFN)-γ and interleukin (IL)-10 were elevated in animals with pathology . Histopathology revealed clusters of acid-fast bacilli in the subcutaneous tissue, with macrophage infiltration and granuloma formation resembling human BU. Our study successfully showed the utility of M. ulcerans IVIS monitoring and lays a foundation for further research.

An enzyme must be soluble, stable, active and easy to produce to be useful in industrial applications. Not all enzymes possess these attributes. We set out to determine how many changes are required to convert an enzyme with poor properties into one that has useful properties. Lipase Lip3 from Drosophila melanogaster had been previously optimised for expression in Escherichia coli. The expression levels were good, but Lip3 was mainly insoluble with poor activity. Directed evolution was used to identify variants with enhanced activity along with improved solubility. Five variants and the wild-type (wt) enzyme were purified and characterised. The yield of the wt enzyme was just 2.2 mg/L of culture, while a variant, produced under the same conditions, gave 351 mg. The improvement of activity of the best variant was 200 times higher than that of the wt when the crude lysates were analysed using pNP-C8, but with purified protein, the improvement observed was 1.5 times higher. This means that most of the increase of activity is due to increase in solubility and stability. All the purified variants showed increased thermal stability compared with the wt enzyme that had a T1/2 of 37°C, while the mutant with P291L of 42.2°C and the mutant R7&#95;47D with five mutations had a value of 52.9°C, corresponding to an improvement of 16°C. The improved variants had between five and nine changes compared with the wt enzyme. There were four changes that were found in all 30 final round variants for which sequences were obtained; three of these changes were found in the substrate-binding domain., (© The Author(s) 2019. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)

The conversion of saturated fatty acids to high value chiral hydroxy-acids and lactones poses a number of synthetic challenges: the activation of unreactive C-H bonds and the need for regio- and stereoselectivity. Here the first example of a wild-type cytochrome P450 monooxygenase (CYP116B46 from Tepidiphilus thermophilus) capable of enantio- and regioselective C5 hydroxylation of decanoic acid 1 to (S)-5-hydroxydecanoic acid 2 is reported. Subsequent lactonization yields (S)-δ-decalactone 3, a high value fragrance compound, with greater than 90 % ee. Docking studies provide a rationale for the high regio- and enantioselectivity of the reaction., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The nargenicin family of antibiotics are macrolides containing a rare ether-bridged cis-decalin motif. Several of these compounds are highly active against multi-drug resistant organisms. Despite the identification of the first members of this family almost 40 years ago, the genetic basis for the production of these molecules and the enzyme responsible for formation of the oxa bridge, remain unknown. Here, the 85 kb nargenicin biosynthetic gene cluster was identified from a human pathogenic Nocardia arthritidis isolate and this locus is solely responsible for nargenicin production. Further investigation of this locus revealed a putative iron-α-ketoglutarate-dependent dioxygenase, which was found to be responsible for the formation of the ether bridge from the newly identified deoxygenated precursor, 8,13-deoxynargenicin. Uncovering the nargenicin biosynthetic locus provides a molecular basis for the rational bioengineering of these interesting antibiotic macrolides., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Digital dental technology is increasingly becoming an integral part of the modern orthodontic practice. The accuracy of digitally articulated models is critical when developing orthodontic treatment plans., Objective: to determine the accuracy of model articulation generated by extraoral and intraoral scanners., Design: One extraoral scanner with a wax (EO W ) or vinyl polysiloxane bite registration (EO VPS ), and three intraoral digital scanners utilizing confocal static (IO CS ), confocal continuous (IO CC ), and blue LED light technologies (IO LED ) were used., Methods: On each scanned image (n = 25 per group), measurements between the maxillary and mandibular molars and canines were performed and then compared to the gold standard values. A deviation of ± 0.5 mm from the gold standard value was considered acceptable. The significance level was kept at 0.05., Results: IO CS and IO CC were accurate for all six interarch measurements. IO LED and EO VPS groups produced the next most accurate articulation of the digital models. EO W group resulted in the least accurate articulation. Also, of the software platforms used, the OrthoCAD™ was found to be the most accurate system for making measurements on digital casts., Conclusions: Only the scanners with the confocal imaging technology produced accurately articulated models. Differences between the scanners may be related to measurement errors inherent to the technologies employed and the software systems used to process the images.

X-ray diffraction measurements to characterize phase transitions of dynamically compressed high-Z matter at Mbar pressures require both sufficient photon energy and fluence to create data with high fidelity in a single shot. Large-scale laser systems can be used to generate x-ray sources above 10 keV utilizing line radiation of mid-Z elements. However, the laser-to-x-ray energy conversion efficiency at these energies is low, and thermal x-rays or hot electrons result in unwanted background. We employ polycapillary x-ray lenses in powder x-ray diffraction measurements using solid target x-ray emission from either the Z-Beamlet long-pulse or the Z-Petawatt (ZPW) short-pulse laser systems at Sandia National Laboratories. Polycapillary lenses allow for a 100-fold fluence increase compared to a conventional pinhole aperture while simultaneously reducing the background significantly. This enables diffraction measurements up to 16 keV at the few-photon signal level as well as diffraction experiments with ZPW at full intensity.

Amplification of the transverse scattered component of stimulated Brillouin scattering (SBS) can contribute to optical damage in the large aperture optics of multi-kJ lasers. Because increased laser bandwidth from optical phase modulation (PM) can suppress SBS, high energy laser amplifiers are injected with PM light. Phase modulation distributes the single-frequency spectrum of a master oscillator laser among individual PM sidebands, so a sufficiently high modulation index β can maintain the fluence for all spectral components below the SBS threshold. To avoid injection of single frequency light in the event of a PM failure, a high-speed PM failsafe system (PMFS) must be employed. Because PM is easily converted to AM, essentially all PM failsafes detect AM, with the one described here employing a novel configuration where optical heterodyne detection converts PM to AM, followed by passive AM power detection. Although the PMFS is currently configured for continuous monitoring, it can also detect PM for pulse durations ≥2 ns and could be modified to accommodate shorter pulses. This PMFS was deployed on the Z-Beamlet Laser (ZBL) at Sandia National Laboratories, as required by an energy upgrade to support programs at Sandia's Z Facility such as magnetized liner inertial fusion. Depending on the origin of a PM failure, the PMFS responds in as little as 7 ns. In the event of an instantaneous failure during initiation of a laser shot, this response time translates to a 30-50 ns margin of safety by blocking a pulse from leaving ZBL's regenerative amplifier, which prevents injection of single frequency light into the main amplification chain. The performance of the PMFS, without the need for operator interaction, conforms to the principles of engineered safety.

Crystal x-ray imaging is frequently used in inertial confinement fusion and laser-plasma interaction applications as it has advantages compared to pinhole imaging, such as higher signal throughput, better achievable spatial resolution, and chromatic selection. However, currently used x-ray detectors are only able to obtain a single time resolved image per crystal. The dilation aided single-line-of-sight x-ray camera described here was designed for the National Ignition Facility (NIF) and combines two recent diagnostic developments, the pulse dilation principle used in the dilation x-ray imager and a ns-scale multi-frame camera that uses a hold and readout circuit for each pixel. This enables multiple images to be taken from a single-line-of-sight with high spatial and temporal resolution. At the moment, the instrument can record two single-line-of-sight images with spatial and temporal resolution of 35 μ m and down to 35 ps, respectively, with a planned upgrade doubling the number of images to four. Here we present the dilation aided single-line-of-sight camera for the NIF, including the x-ray characterization measurements obtained at the COMET laser, as well as the results from the initial timing shot on the NIF.

The first crystal structure of a class VII P450, CYP116B46 from Tepidiphilus thermophilus, has been solved at 1.9 Å resolution. The structure reveals overall conservation of the P450-fold and a water conduit around the I-helix. Active site residues have been identified and sequence comparisons have been made with other class VII enzymes. A structure similarity search demonstrated that the P450-TT structure is similar to enzymes capable of oxy-functionalization of fatty acids, terpenes, macrolides, steroids and statins. The insight gained from solving this structure will provide a guideline for future engineering and modelling studies on this catalytically promiscuous class of enzymes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Cytochrome P450 monooxygenases are able to catalyse a range of synthetically challenging reactions ranging from hydroxylation and demethylation to sulfoxidation and epoxidation. As such they have great potential for biocatalytic applications but are underutilised due to often-poor expression, stability and solubility in recombinant bacterial hosts. The use of self-sufficient P450 s with fused haem and reductase domains has already contributed heavily to improving catalytic efficiency and simplifying an otherwise more complex multi-component system of P450 and redox partners. Herein, we present a new addition to the class VII family with the cloning, sequencing and characterisation of the self-sufficient CYP116B62 Hal1 from Halomonas sp. NCIMB 172, the genome of which has not yet been sequenced. Hal1 exhibits high levels of expression in a recombinant E. coli host and can be utilised from cell lysate or used in purified form. Hal1 favours NADPH as electron donor and displays a diverse range of activities including hydroxylation, demethylation and sulfoxidation. These properties make Hal1 suitable for future biocatalytic applications or as a template for optimisation through engineering., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Plasmid vectors based on bacteriophage integrases are important tools in molecular microbiology for the introduction of foreign DNA, especially into bacterial species where other systems for genetic manipulation are limited. Site specific integrases catalyze recombination between phage and bacterial attachment sites ( attP and attB , respectively) and the best studied integrases in the actinomycetes are the serine integrases from the Streptomyces bacteriophages ΦC31 and ΦBT1. As this reaction is unidirectional and highly stable, vectors containing phage integrase systems have been used in a number of genetic engineering applications. Plasmids bearing the ΦBT1 integrase have been used to introduce DNA into Streptomyces and Amycolatopsis strains; however, they have not been widely studied in other actinobacterial genera. Here, we show that vectors based on ΦBT1 integrase can stably integrate into the chromosomes of a range of Nocardia species, and that this integration occurs despite the absence of canonical attB sites in these genomes. Furthermore, we show that a ΦBT1 integrase-based vector can insert at multiple pseudo- attB sites within a single strain and we determine the sequence of a pseudo- attB motif. These data suggest that ΦBT1 integrase-based vectors can be used to readily and semi-randomly introduce foreign DNA into the genomes of a range of Nocardia species. However, the precise site of insertion will likely require empirical determination in each species to avoid unexpected off-target effects., Competing Interests: Timothy P Stinear is an Academic Editor for PeerJ.

Since 2000, cases of the neglected tropical disease Buruli ulcer, caused by infection with Mycobacterium ulcerans , have increased 100-fold around Melbourne (population 4.4 million), the capital of Victoria, in temperate southeastern Australia. The reasons for this increase are unclear. Here, we used whole-genome sequence comparisons of 178 M. ulcerans isolates obtained primarily from human clinical specimens, spanning 70 years, to model the population dynamics of this pathogen from this region. Using phylogeographic and advanced Bayesian phylogenetic approaches, we found that there has been a migration of the pathogen from the east end of the state, beginning in the 1980s, 300 km west to the major human population center around Melbourne. This move was then followed by a significant increase in M. ulcerans population size. These analyses inform our thinking around Buruli ulcer transmission and control, indicating that M. ulcerans is introduced to a new environment and then expands, rather than it being from the awakening of a quiescent pathogen reservoir. IMPORTANCE Buruli ulcer is a destructive skin and soft tissue infection caused by Mycobacterium ulcerans and is characterized by progressive skin ulceration, which can lead to permanent disfigurement and long-term disability. Despite the majority of disease burden occurring in regions of West and central Africa, Buruli ulcer is also becoming increasingly common in southeastern Australia. Major impediments to controlling disease spread are incomplete understandings of the environmental reservoirs and modes of transmission of M. ulcerans The significance of our research is that we used genomics to assess the population structure of this pathogen at the Australian continental scale. We have then reconstructed a historical bacterial spread and modeled demographic dynamics to reveal bacterial population expansion across southeastern Australia. These findings provide explanations for the observed epidemiological trends with Buruli ulcer and suggest possible management to control disease spread., (Copyright © 2018 American Society for Microbiology.)

Cytochrome P450 monooxygenases are highly desired biocatalysts owing to their ability to catalyse a wide variety of chemically challenging C-H activation reactions. The CYP102A subfamily of enzymes are natural catalytically self-sufficient proteins consisting of a haem and FMN-FAD reductase domain fused in a single-component system. They catalyse the oxygenation of saturated and unsaturated fatty acids to produce primarily ω-1, ω-2 and ω-3 hydroxy acids. These monooxygenases have potential applications in biotechnology; however, their substrate range is still limited and there is a continued need to add diversity to this class of biocatalysts. Herein, we present the characterisation of two new members of this class of enzymes, CYP102A25 (BMar) from Bacillus marmarensis and CYP102A26 (PHal) from Pontibacillus halophilus, both of which express readily in a recombinant bacterial host. BMar exhibits the highest activity toward myristic acid and shows moderate activity towards unsaturated fatty acids. PHal exhibits broader activity towards mid-chain-saturated (C 14 -C 18 ) and unsaturated fatty acids. Furthermore, PHal shows good regioselectivity for the hydroxylation of myristic acid, targeting the ω-2 position for C-H activation., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This exploratory study examines the impact of auditory status, gender, and prior sexual victimization on attitudes and behaviors related to date rape among undergraduate college students (n = 3,352) at a private university in the northeast. An abbreviated version of the College Date Rape Attitude and Behavior Survey (Lanier & Elliot, 1997) and the Sexual Experiences Survey (Koss, Gidycz, & Wisniewski, 1987) were employed. Findings indicated that Deaf and hard of hearing (DHH) students were more likely to experience negative sexual experiences than hearing students. No differences were found in rape-supportive attitudes by auditory status. The analysis also found that DHH students were more likely to engage in sexual behaviors that increase the risk of date rape than were hearing students. Finally, significant differences were found regarding gender and prior sexual victimization on rape attitudes and behaviors. Implications and directions for future research are discussed.

The world's freshwater biotas are declining in diversity, range and abundance, more than in other realms, with human appropriation of water. Despite considerable data on the distribution of dams and their hydrological effects on river systems, there are few expansive and long analyses of impacts on freshwater biota. We investigated trends in waterbird communities over 32 years, (1983-2014), at three spatial scales in two similarly sized large river basins, with contrasting levels of water resource development, representing almost a third (29%) of Australia: the Murray-Darling Basin and the Lake Eyre Basin. The Murray-Darling Basin is Australia's most developed river basin (240 dams storing 29,893 GL) while the Lake Eyre Basin is one of the less developed basins (1 dam storing 14 GL). We compared the long-term responses of waterbird communities in the two river basins at river basin, catchment and major wetland scales. Waterbird abundances were strongly related to river flows and rainfall. For the developed Murray-Darling Basin, we identified significant long-term declines in total abundances, functional response groups (e.g., piscivores) and individual species of waterbird (n = 50), associated with reductions in cumulative annual flow. These trends indicated ecosystem level changes. Contrastingly, we found no evidence of waterbird declines in the undeveloped Lake Eyre Basin. We also modelled the effects of the Australian Government buying up water rights and returning these to the riverine environment, at a substantial cost (>3.1 AUD billion) which were projected to partly (18% improvement) restore waterbird abundances, but projected climate change effects could reduce these benefits considerably to only a 1% or 4% improvement, with respective annual recovery of environmental flows of 2,800 GL or 3,200 GL. Our unique large temporal and spatial scale analyses demonstrated severe long-term ecological impact of water resource development on prominent freshwater animals, with implications for global management of water resources., (© 2017 John Wiley & Sons Ltd.)