Giant valley-Zeeman coupling in the surface layer of an intercalated transition metal dichalcogenide.

Spin-valley locking is ubiquitous among transition metal dichalcogenides with local or global inversion asymmetry, in turn stabilizing properties such as Ising superconductivity, and opening routes towards 'valleytronics'. The underlying valley-spin splitting is set by spin-orbit coupling but can be tuned via the application of external magnetic fields or through proximity coupling. However, only modest changes have been realized to date. Here, we investigate the electronic structure of the V-intercalated transition metal dichalcogenide V1/3NbS2 using microscopic-area spatially resolved and angle-resolved photoemission spectroscopy. Our measurements and corresponding density functional theory calculations reveal that the bulk magnetic order induces a giant valley-selective Ising coupling exceeding 50 meV in the surface NbS2 layer, equivalent to application of a ~250 T magnetic field. This energy scale is of comparable magnitude to the intrinsic spin-orbit splittings, and indicates how coupling of local magnetic moments to itinerant states of a transition metal dichalcogenide monolayer provides a powerful route to controlling their valley-spin splittings.

Patterns and trends in lake concentrations of dissolved organic carbon in a landscape recovering from environmental degradation and widespread acidification.

Concentrations of dissolved organic carbon (DOC) have increased in lakes throughout North America and Europe over the last three decades. Recovery from acid deposition and climate change have both been postulated as the primary mechanisms for the increase in DOC. To provide a clearer insight into the mechanisms responsible for increasing DOC we evaluated changes in lake and peat porewater chemistry collected in an area of approximately 33,000 km2 surrounding Sudbury, Ontario, a region undergoing dramatic recovery from acidic deposition. DOC concentrations varied considerably among the 44 lakes and over time (samples annually from 1981 to 2018), but the Sens Slope value showed a strong increase in lake DOC concentration over time, at 0.05 mg/ L y-1 (p < 0.001) that was related to increasing pH [0.03 units y-1, p < 0.001] and decreasing lake SO4 concentration [-0.24 mg/ L y-1; p < 0.001], but showed no relationship with temperature or precipitation. Similar strong relationships between DOC and pH (positive) and SO4 (negative) were observed in 18 peatlands sampled in the region. In a spatial analysis of 82 lakes sampled in 2018, concentrations of DOC in lakes were highest in flatter catchments with a greater wetland area, suggesting that wetlands are a major source of DOC in lakes. Optical properties of DOC obtained from extracts of wetland and upland soils at 6 catchments could be distinguished, primarily due to upland litter extracts having distinct optical properties from mineral soils or wetland soils. Optical properties of DOC in lakes however were inconsistent with those measured in soil extracts indicating that they are not useful for distinguishing DOC sources in these lakes. A predictive model was developed to explain DOC trends within Sudbury lakes using a stepwise linear regression combined with hierarchical partitioning to confirm the most influential processes on DOC. Almost 50% of the variability in DOC change in the 44 lakes was explained by the magnitude in lake pH change, catchment size and catchment sparse tree cover showing that recovery from acidic deposition is overwhelmingly responsible for increasing DOC in Sudbury lakes.

Cancer patients with fractures are rarely assessed or treated for osteoporosis: a population-based study.

Among 4238 cancer and 16,418 cancer-free individuals with incident major non-traumatic fractures (hip, clinical vertebral, forearm, humerus), post-fracture osteoporosis care was equally poor for both groups, whether assessed from bone mineral density (BMD) testing, initiation of osteoporosis therapy or either intervention (BMD testing and/or osteoporosis therapy). INTRODUCTION: Most individuals sustaining a fracture do not undergo evaluation and/or treatment for osteoporosis. Cancer survivors are at increased risk for osteoporosis and fracture. Whether cancer survivors experience a similar post-fracture "care gap" is unclear. Using population-based databases, we assessed whether cancer patients are evaluated and/or treated for osteoporosis after a major fracture. METHODS: From the Manitoba Cancer Registry, we identified cancer cases (first cancer diagnosis between 1987 and 2013) and cancer-free controls with incident major non-traumatic fractures (from provincial physician billing claims and hospitalization databases). The outcomes were performance of BMD testing (from the BMD Registry), initiation of osteoporosis therapy (from drug dispensation database) or either intervention (BMD testing and/or osteoporosis therapy) in the 12 months post-fracture. RESULTS: There were 4238 cancer and 16,418 cancer-free individuals who sustained a fracture after the index date (cancer diagnosis) and were followed for at least 1 year post-fracture. Subsequent BMD testing was performed in 11.0% of cancer cases versus 11.5% non-cancer controls (P = 0.43), osteoporosis treatment in 22.9% cancer cases versus 21.8% non-cancer controls (P = 0.15), and either testing or treatment in 28.9% cancer cases versus 28.4% non-cancer controls (P = 0.53). Predictors of BMD testing and/or initiation of therapy were similar for non-cancer and cancer patients. Post-fracture interventions were consistently used more frequently among women, older patients (age 50 years or older), those who sustained fractures in a later calendar period, and (for treatment) after vertebral fracture. Cancer-specific variables (cancer type, years from cancer diagnosis to fracture, specialty of care provider) showed only weak and inconsistent effects. CONCLUSIONS: A large care gap exists among cancer patients who sustain a fracture, similar to the general population, whereby the evaluation or treatment for osteoporosis is seldom conducted. Care maps may need to be developed for cancer populations to improve post-fracture care.

High-risk Pediatric Emergencies.

More than half of pediatric malpractice cases arise from emergency departments, primarily due to missed or delayed diagnoses. All providers who take care of children in emergency departments should be aware of this risk and the most common diagnoses associated with medicolegal liability. This article focuses on diagnosis and management of high-risk diagnoses in pediatric patients presenting to emergency departments, including meningitis, pneumonia, appendicitis, testicular torsion, and fracture. It highlights challenges and pitfalls that may increase risk of liability. It concludes with a discussion on recognition and management of abuse in children, including when to report and decisions on disposition.

High-fidelity scaling relationships for determining dissipative particle dynamics parameters from atomistic molecular dynamics simulations of polymeric liquids.

An optimized Dissipative Particle Dynamics (DPD) model with simple scaling rules was developed for simulating entangled linear polyethylene melts. The scaling method, which can be used for mapping dimensionless (reduced units) DPD simulation data to physical units, was based on scaling factors for three fundamental physical units; namely, length, time, and viscosity. The scaling factors were obtained as ratios of equilibrium Molecular Dynamics (MD) simulation data in physical units and equivalent DPD simulation data for relevant quantities. Specifically, the time scaling factor was determined as the ratio of longest relaxation times, the length scaling factor was obtained as the ratio of the equilibrium end-to-end distances, and the viscosity scaling factor was calculated as the ratio of zero-shear viscosities, each as obtained from the MD (in physical units) and DPD (reduced units) simulations. The scaling method was verified for three MD/DPD model liquid pairs under several different nonequilibrium conditions, including transient and steady-state simple shear and planar elongational flows. Comparison of the MD simulation results with those of the scaled DPD simulations revealed that the optimized DPD model, expressed in terms of the proposed scaling method, successfully reproduced the computationally expensive MD results using relatively cheaper DPD simulations.

Clinical Outcomes Associated With Escherichia coli Infections in Adults With Cystic Fibrosis: A Cohort Study.

BACKGROUND: Analysis of "emerging" pathogens in cystic fibrosis (CF) lung disease has focused on unique pathogens that are rare in other human diseases or are drug resistant. Escherichia coli is recovered in the sputum of up to 25% of patients with CF, yet little is known about the epidemiology or clinical impact of infection. METHODS: We studied patients attending a Canadian adult CF clinic who had positive sputum cultures for E coli from 1978 to 2016. Infection was categorized as transient or persistent (≥3 positive sputum cultures, spanning >6 months). Those with persistent infection were matched 2:1 with age, sex, and time-period controls without history of E coli infection, and mixed-effects models were used to assess pulmonary exacerbation (PEx) frequency, lung function decline, hospitalization, and intravenous antibiotic days. RESULTS: Forty-five patients (12.3%) had E coli recovered from sputum samples between 1978 and 2016, and 18 patients (40%) developed persistent infection. Nine patients (24%) had PEx at incident infection, and increased bioburden was predictive of exacerbation (P = .03). Risk factors for persistent infection included lower nutritional status (P < .001) and lower lung function (P = .009), but chronic infection with Pseudomonas aeruginosa was protective. There was no difference in annual lung function decline, need for hospitalization or intravenous antibiotics, or risk of PEx in patients with persistent infection. CONCLUSIONS: Persistent E coli infection was frequent and was more common in CF patients with low nutritional status and lung function. However, this does not predict clinical decline. Multicenter studies would allow better characterization of the epidemiology and clinical impact of E coli infection.

Variability in Informed Consent Practices for Non-Emergent Procedures in Pediatric Emergency Departments.

Although informed consent is a cornerstone of medical ethics, it is unclear if the practice for obtaining informed consent is consistent among pediatric emergency departments. This study's goal is to describe the current practice for written informed consent in academic pediatric emergency departments for non-emergent procedures. A questionnaire distributed to pediatric emergency medicine fellowship directors queried whether written informed consent was standard of care for 15 procedures and assessed departmental consent policies and use of "blanket" consent-to-treat forms. Response rate was 80% (n = 64). Institutions obtained written consent for a mean of 4.4 procedures. Written informed consent was most commonly obtained for procedural sedation (82.5%), blood transfusion (72.9%), and lumbar puncture (66.5%). Twenty-one institutions (32.8%) had policies specifying procedures requiring written consent. Thirty-five institutions (54.7%) used "blanket" consent-to-treat forms. Our results suggest that there is variability in the use of written informed consent for non-emergent procedures among academic pediatric emergency departments.

A population study of prolonged grief in refugees.

AIMS: Despite the frequency that refugees suffer bereavement, there is a dearth of research into the prevalence and predictors of problematic grief reactions in refugees. To address this gap, this study reports a nationally representative population-based study of refugees to determine the prevalence of probable prolonged grief disorder (PGD) and its associated problems. METHODS: This study recruited participants from the Building a New Life in Australia (BNLA) prospective cohort study of refugees admitted to Australia between October 2013 and February 2014. The current data were collected in 2015-2016, and comprised 1767 adults, as well as 411 children of the adult respondents. Adult refugees were assessed for trauma history, post-migration difficulties, probable PGD, post-traumatic stress disorder (PTSD) and mental illness. Children were administered the Strengths and Difficulties Questionnaire. RESULTS: In this cohort, 38.1% of refugees reported bereavement, of whom 15.8% reported probable PGD; this represents 6.0% of the entire cohort. Probable PGD was associated with a greater likelihood of mental illness, probable PTSD, severe mental illness, currently unemployed and reported disability. Children of refugees with probable PGD reported more psychological difficulties than those whose parents did not have probable PGD. Probable PGD was also associated with the history of imprisonment, torture and separation from family. Only 56.3% of refugees with probable PGD had received psychological assistance. CONCLUSIONS: Bereavement and probable PGD appear highly prevalent in refugees, and PGD seems to be associated with disability in the refugees and psychological problems in their children. The low rate of access to mental health assistance for these refugees highlights that there is a need to address this issue in refugee populations.

Paediatric hearing loss: a community-based survey in peri-urban Kumasi, Ghana.

BACKGROUND: Paediatric hearing loss rates in Ghana are currently unknown. METHODS: A cross-sectional study was conducted in peri-urban Kumasi, Ghana; children (aged 3-15 years) were recruited from randomly selected households. Selected children underwent otoscopic examination prior to in-community pure tone screening using the portable ShoeBox audiometer. The LittlEars auditory questionnaire was also administered to caregivers and parents. RESULTS: Data were collected from 387 children. After conditioning, 362 children were screened using monaural pure tones presented at 25 dB. Twenty-five children could not be conditioned to behavioural audiometric screening. Eight children were referred based on audiometric screening results. Of those, four were identified as having hearing loss. Four children scored less than the maximum mark of 35 on the LittleEars questionnaire. Of those, three had hearing loss as identified through pure tone screening. The predominant physical finding on otoscopy was ear canal cerumen impaction. CONCLUSION: Paediatric hearing loss is prevalent in Ghana, and should be treated as a public health problem warranting further evaluation and epidemiology characterisation.

Portable audiometric screening platforms used in low-resource settings: a review.

BACKGROUND: Millions of people across the world suffer from disabling hearing loss. Appropriate interventions lead to improved speech and language skills, educational advancement, and improved social integration. A major limitation to improving care is identifying those with disabling hearing loss in low-resource countries. OBJECTIVES: This review article summarises information on currently available hearing screening platforms and technology available from published reports and the authors' personal experiences of hearing loss identification in low-resource areas of the world. The paper reviews the scope and capabilities of portable hearing screening platforms, including the pros and cons of each technology and how they have been utilised in low-resource environments. CONCLUSION: Portable hearing screening tools are readily available to assess hearing loss in low-resource areas. Each technology has advantages and limitations that should be considered when identifying the optimal methods to assess needs in each country.

The American Orthopaedic Association's Own the Bone® database: a national quality improvement project for the treatment of bone health in fragility fracture patients.

The American Orthopaedic Association initiated the Own the Bone (OTB) quality improvement program in 2009. Herein we show that the data collected through this program is similar to that collected in other large studies. Thus, the OTB registry functions as an externally valid cohort for studying fragility fracture patients. INTRODUCTION: The American Orthopedic Association initiated the Own the Bone (OTB) quality improvement program in 2009 to improve secondary prevention of fragility fractures. In this study, we present a summary of the data collected by the OTB program and compare it to data from other large fragility fracture registries with an aim to externally validate the OTB registry. METHODS: The OTB registry contained 35,038 unique cases of fragility fracture as of September, 2016. We report the demographics, presenting fracture characteristics, past fracture history, and bone mineral density (BMD) data and compare these to data from large fragility fracture studies across the world. RESULTS: Seventy-three percent of the patients in the OTB registry were female, Caucasian, and post-menopausal. In 54.4% of cases, patients had a hip fracture; spine fractures were the second most common fracture type occurring in 11.1% of patients. Thirty-four percent of the patients had a past history of fragility fracture, and the most common sites were the spine and hip. The average femoral neck T-score was - 2.06. When compared to other studies, the OTB database showed similar findings with regard to patient age, gender, race, BMI, BMD profile, prior fracture history, and family history of fragility fractures. CONCLUSION: OTB is the first and largest multi-center voluntary fragility fracture registry in the USA. The data collected through the OTB program is comparable to that collected in international studies. Thus, the OTB registry functions as an externally valid cohort for further studies assessing the clinical characteristics, interventions, and outcomes achieved in patients who present with a fragility fracture in the USA.

Factors associated with delayed infant immunization in a nationally representative cohort study.

BACKGROUND: Many children in developed countries do not receive recommended vaccines on time. However, knowledge about factors related to timeliness remains limited. Quantifying the relative impact of parental attitudes compared with socio-demographic factors for delayed immunization would inform policy responses. METHODS: Participants in the nationally representative Longitudinal Study of Australian Children were matched with their vaccination histories in the Australian Childhood Immunisation Register (N = 4,121). Information about the children and their families were collected in face-to-face interviews in 2003-2004. We considered whether children had completed the primary course for each recommended antigen due by 6 months old. Children were categorized as either fully immunized, delayed, or totally non-immunized. The outcome was examined using logistic regression. Population attributable fractions were estimated for key predictors. RESULTS: Delayed immunization was significantly associated with indicators of social disadvantage as well as parental disagreement with immunization. Attributable fractions for delayed immunization included lone motherhood (3.8%; 95% confidence interval CI [0.8, 6.7]), larger family size (39.5%; 95% CI [31.2, 46.8]), residential mobility (3.3%; 95% CI [0.1, 6.5]), lack of private hospital insurance (9.4%; 95% CI [0.7, 17.3]), a medical condition in the child (2.0%; 95% CI [0.2, 3.9]), and parental disagreement with immunization (2.1%; 95% CI [0.3, 3.9]). CONCLUSIONS: Parental attitudes accounted for a relatively small percentage of delayed infant immunization. In contrast, many children who did not receive vaccines on time were characterized by social disadvantage, especially larger family size. Researchers and policy-makers should consider how to make timely immunization easier for busy parents.

Hyponatremia as the Presenting Feature of a Pituitary Abscess in a Calf.

A 2-month-old Simmental heifer presented for acute onset of neurological behavior. Laboratory tests confirmed the presence of hyponatremia, hypochloremia, and hypokalemia that improved with intravenous fluid therapy. Despite an initial cessation of neurological signs, symptoms re-emerged, and the heifer was euthanized due to poor prognosis. A pituitary abscess (Trueperella pyogenes) was observed on gross necropsy, suggesting that the effects of panhypopituitarism (inappropriate anti-diuretic hormone (ADH), adrenocorticotropic hormone (ACTH), and/or thyroid-stimulating hormone (TSH) secretion) may have resulted in the clinical findings. Pituitary abscess syndrome carries a poor prognosis due to the inability to penetrate the area with systemic antibiotic therapy. These findings highlight the unusual clinical presentations that may occur following pituitary abscess syndrome in cattle that practitioners need to consider when determining prognosis.

First Searches for Axions and Axionlike Particles with the LUX Experiment.

The first searches for axions and axionlike particles with the Large Underground Xenon experiment are presented. Under the assumption of an axioelectric interaction in xenon, the coupling constant between axions and electrons g_{Ae} is tested using data collected in 2013 with an exposure totaling 95 live days ×118 kg. A double-sided, profile likelihood ratio statistic test excludes g_{Ae} larger than 3.5×10^{-12} (90% C.L.) for solar axions. Assuming the Dine-Fischler-Srednicki-Zhitnitsky theoretical description, the upper limit in coupling corresponds to an upper limit on axion mass of 0.12 eV/c^{2}, while for the Kim-Shifman-Vainshtein-Zhakharov description masses above 36.6 eV/c^{2} are excluded. For galactic axionlike particles, values of g_{Ae} larger than 4.2×10^{-13} are excluded for particle masses in the range 1-16 keV/c^{2}. These are the most stringent constraints to date for these interactions.

Limits on Spin-Dependent WIMP-Nucleon Cross Section Obtained from the Complete LUX Exposure.

We present experimental constraints on the spin-dependent WIMP-nucleon elastic cross sections from the total 129.5 kg yr exposure acquired by the Large Underground Xenon experiment (LUX), operating at the Sanford Underground Research Facility in Lead, South Dakota (USA). A profile likelihood ratio analysis allows 90% C.L. upper limits to be set on the WIMP-neutron (WIMP-proton) cross section of σ_{n}=1.6×10^{-41} cm^{2} (σ_{p}=5×10^{-40} cm^{2}) at 35 GeV c^{-2}, almost a sixfold improvement over the previous LUX spin-dependent results. The spin-dependent WIMP-neutron limit is the most sensitive constraint to date.

Prevalence and Outcomes of Achromobacter Species Infections in Adults with Cystic Fibrosis: a North American Cohort Study.

Achromobacter species are increasingly being detected in cystic fibrosis (CF) patients, with an unclear epidemiology and impact. We studied a cohort of patients attending a Canadian adult CF clinic who had positive sputum cultures for Achromobacter species in the period from 1984 to 2013. Infection was categorized as transient or persistent (≥50% positive cultures for 1 year). Those with persistent infection were matched 2:1 with age-, sex-, and time-matched controls without a history of Achromobacter infection, and mixed-effects models were used to assess pulmonary exacerbation (PEx) frequency and lung function decline. Isolates from a biobank were retrospectively assessed, identified to the species level by nrdA sequencing, and genotyped using pulsed-field gel electrophoresis (PFGE). Thirty-four patients (11% of those in our clinic), with a median age of 24 years (interquartile range [IQR], 20.3 to 29.8 years), developed Achromobacter infection. Ten patients (29%) developed persistent infection. Persistence did not denote permanence, as most patients ultimately cleared infection, often after years. Patients were more likely to experience PEx at incident isolation than at prior or subsequent visits (odds ratio [OR], 2.7 [95% confidence interval {CI}, 1.2 to 6.7]; P = 0.03). Following persistent infection, there was no difference in annual lung function decline (-1.08% [95% CI, -2.73 to 0.57%] versus -2.74% [95% CI, -4.02 to 1.46%]; P = 0.12) or the odds of PEx (OR, 1.21 [95% CI, 0.45 to 3.28]; P = 0.70). Differential virulence among Achromobacter species was not observed, and no cases of transmission occurred. We demonstrated that incident Achromobacter infection was associated with a greater risk of PEx; however, neither transient nor chronic infection was associated with a worsened long-term prognosis. Large, multicenter studies are needed to clarify the clinical impact, natural history, and transmissibility of Achromobacter.

Otolaryngology outreach to Komfo Anokye Teaching Hospital: a medical and educational partnership.

BACKGROUND: Medical and educational partnerships between high- and low-resourced countries provide opportunities to have a long-term meaningful impact on medical training and healthcare delivery. METHODS: An otolaryngology partnership between Komfo Anokye Teaching Hospital in Kumasi, Ghana, and the University of Michigan Department of Otolaryngology/Head and Neck Surgery has been undertaken to enhance healthcare delivery at both institutions. RESULTS: A temporal bone dissection laboratory, with the equipment to perform dedicated otological surgery, and academic platforms for clinical and medical education and residency training have been established. CONCLUSION: This article describes the details of this partnership in otological surgery and hearing health, with an emphasis on creating in-country surgical simulation, training on newly acquired medical equipment and planning regarding the formulation of objectified metrics to gauge progress going forward.

Results from a Search for Dark Matter in the Complete LUX Exposure.

We report constraints on spin-independent weakly interacting massive particle (WIMP)-nucleon scattering using a 3.35×10^{4} kg day exposure of the Large Underground Xenon (LUX) experiment. A dual-phase xenon time projection chamber with 250 kg of active mass is operated at the Sanford Underground Research Facility under Lead, South Dakota (USA). With roughly fourfold improvement in sensitivity for high WIMP masses relative to our previous results, this search yields no evidence of WIMP nuclear recoils. At a WIMP mass of 50 GeV c^{-2}, WIMP-nucleon spin-independent cross sections above 2.2×10^{-46} cm^{2} are excluded at the 90% confidence level. When combined with the previously reported LUX exposure, this exclusion strengthens to 1.1×10^{-46} cm^{2} at 50 GeV c^{-2}.

Improved Limits on Scattering of Weakly Interacting Massive Particles from Reanalysis of 2013 LUX Data.

We present constraints on weakly interacting massive particles (WIMP)-nucleus scattering from the 2013 data of the Large Underground Xenon dark matter experiment, including 1.4×10^{4} kg day of search exposure. This new analysis incorporates several advances: single-photon calibration at the scintillation wavelength, improved event-reconstruction algorithms, a revised background model including events originating on the detector walls in an enlarged fiducial volume, and new calibrations from decays of an injected tritium ß source and from kinematically constrained nuclear recoils down to 1.1 keV. Sensitivity, especially to low-mass WIMPs, is enhanced compared to our previous results which modeled the signal only above a 3 keV minimum energy. Under standard dark matter halo assumptions and in the mass range above 4 GeV c^{-2}, these new results give the most stringent direct limits on the spin-independent WIMP-nucleon cross section. The 90% C.L. upper limit has a minimum of 0.6 zb at 33 GeV c^{-2} WIMP mass.