NNLO QCD predictions for Z-boson production in association with a charm jet within the LHCb fiducial region.

We compute next-to-next-to-leading order (NNLO) QCD corrections to neutral vector boson production in association with a charm jet at the LHC. This process is studied in the forward kinematics at s = 13  TeV, which may provide valuable constraints on the intrinsic charm component of the proton. A comparison is performed between fixed order and NLO predictions matched to a parton shower showing mutual compatibility within the respective uncertainties. NNLO corrections typically lead to a reduction of theoretical uncertainties by a factor of two and the perturbative convergence is further improved through the introduction of a theory-inspired constraint on the transverse momentum of the vector boson plus jet system. A comparison between these predictions with data will require an alignment of a flavour-tagging procedure in theory and experiment that is infrared and collinear safe.

NNLO interpolation grids for jet production at the LHC.

Fast interpolation-grid frameworks facilitate an efficient and flexible evaluation of higher-order predictions for any choice of parton distribution functions or value of the strong coupling α s . They constitute an essential tool for the extraction of parton distribution functions and Standard Model parameters, as well as studies of the dependence of cross sections on the renormalisation and factorisation scales. The APPLfast project provides a generic interface between the parton-level Monte Carlo generator and both the APPLgrid and the fastNLO libraries for the grid interpolation. The extension of the project to include hadron-hadron collider processes at next-to-next-to-leading order in perturbative QCD is presented, together with an application for jet production at the LHC.

Central line-associated bloodstream infections at the multidisciplinary intensive care unit of Universitas Academic Hospital, Bloemfontein, South Africa.

Background: Central line-associated bloodstream infections (CLABSIs) are frequently encountered device-related healthcare-associated infections in critically ill patients, causing substantial morbidity, mortality and prolonged hospitalisation. Objectives: To determine the incidence of CLABSI, median catheter dwell-time prior to developing CLABSI, as well as the causative microorganisms of CLABSI among patients admitted to the multidisciplinary intensive care unit (MICU) at Universitas Academic Hospital, Bloemfontein. Methods: We conducted a retrospective review of medical and laboratory records of all MICU patients who had a central line placed between January and December 2018. Results: A total of 377 patients were admitted to the MICU in 2018, of which 182 met the inclusion criteria for the present study. From the cohort of 182 patients, 16.5% (n=30) of patients presented with 32 CLABSI episodes, with two patients having had two independent episodes each. A total of 1 215 central line days were recorded, yielding a CLABSI rate of 26.3/1 000-line days. Laboratory analysis identified microorganisms in 38 blood cultures, with Gram-negative organisms (55.3%; n=21) being predominant over Gram-positive organisms (39.5%; n=15) and fungi (5.3%; n=2). Conclusion: The incidence of CLABSI at the MICU at Universitas Academic Hospital is high. Urgent intervention with strict compliance to prevention bundles is required to reduce the high incidence of CLABSI.

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States.

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks.

Fully Differential Higgs Boson Production to Third Order in QCD.

We present the first fully differential predictions for the production cross section of a Higgs boson via the gluon fusion mechanism at next-to-next-to-next-to-leading order (N^{3}LO) in QCD perturbation theory. Differential distributions are shown for the two-photon final state produced by the decay of the Higgs boson for a realistic set of fiducial cuts. The N^{3}LO corrections exhibit complex features and are in part larger than the inclusive N^{3}LO corrections to the production cross section. Overall, we observe that the inclusion of the N^{3}LO QCD corrections significantly reduces the perturbative uncertainties and leads to a stabilization of the perturbative expansion.

Treatment outcomes of Acinetobacter baumannii -associated pneumonia and/or bacteraemia at the intensive care unit of Universitas Academic Hospital, Bloemfontein, South Africa.

BACKGROUND: Nosocomial infection with multidrug-resistant (MDR) Acinetobacter baumannii is associated with high mortality rates and the optimal treatment regimen is uncertain. OBJECTIVES: To compare outcomes, as well as ICU and in-hospital survival rates of patients with A. baumannii pneumonia and/or bacteraemia who were treated with colistin monotherapy v. colistin/tigecycline combination therapy. METHODS: This was a retrospective cross-sectional study of patients admitted to the multidisciplinary ICU of Universitas Academic Hospital, Bloemfontein, South Africa, between 1 January 2018 and 31 December 2019. RESULTS: Sixteen patients were included in the study. Nine patients were treated with a combination of colistin and tigecycline, while 7 patients were treated with colistin only. Seven out of 9 (77.8%) patients in the colistin/tigecycline combination therapy group were treated successfully and survived until discharge from ICU, as opposed to 2 out of 7 (28.6%) in the colistin monotherapy group (relative risk (RR) 2.7; 95% CI 0.80 - 9.24). Five out of 9 (55.6%) in the colistin/tigecycline combination therapy group v. 2 out of 7 (28.6%) in the colistin monotherapy group survived until discharge from hospital (RR 1.94; 95% CI 0.53 - 7.20). CONCLUSION: Although ICU survival in patients with A. baumannii infection was better when treated with colistin/tigecycline combination therapy compared with colistin monotherapy, a statistically significant difference could not be detected. Adequately powered prospective clinical trials are required to detect statistically significant differences in treatment outcomes.

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the US

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multi-model ensemble forecast that combined predictions from dozens of different research groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naive baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-week horizon 3-5 times larger than when predicting at a 1-week horizon. This project underscores the role that collaboration and active coordination between governmental public health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks. Significance StatementThis paper compares the probabilistic accuracy of short-term forecasts of reported deaths due to COVID-19 during the first year and a half of the pandemic in the US. Results show high variation in accuracy between and within stand-alone models, and more consistent accuracy from an ensemble model that combined forecasts from all eligible models. This demonstrates that an ensemble model provided a reliable and comparatively accurate means of forecasting deaths during the COVID-19 pandemic that exceeded the performance of all of the models that contributed to it. This work strengthens the evidence base for synthesizing multiple models to support public health action.

Predictions for Z-Boson Production in Association with a b-Jet at O(α_{s}

Precise predictions are provided for the production of a Z boson and a b-jet in hadron-hadron collisions within the framework of perturbative QCD, at O(α_{s}^{3}). To obtain these predictions, we perform the first calculation of a hadronic scattering process involving the direct production of a flavored jet at next-to-next-to-leading-order accuracy in massless QCD and extend techniques to also account for the impact of finite heavy-quark mass effects. The predictions are compared to CMS data obtained in pp collisions at a center-of-mass energy of 8 TeV, which are the most precise data from run I of the LHC for this process, where a good description of the data is achieved. To allow this comparison, we have performed an unfolding of the data, which overcomes the long-standing issue that the experimental and theoretical definitions of jet flavor are incompatible.

Ensemble Forecasts of Coronavirus Disease 2019 (COVID-19) in the U.S.

BackgroundThe COVID-19 pandemic has driven demand for forecasts to guide policy and planning. Previous research has suggested that combining forecasts from multiple models into a single "ensemble" forecast can increase the robustness of forecasts. Here we evaluate the real-time application of an open, collaborative ensemble to forecast deaths attributable to COVID-19 in the U.S. MethodsBeginning on April 13, 2020, we collected and combined one- to four-week ahead forecasts of cumulative deaths for U.S. jurisdictions in standardized, probabilistic formats to generate real-time, publicly available ensemble forecasts. We evaluated the point prediction accuracy and calibration of these forecasts compared to reported deaths. ResultsAnalysis of 2,512 ensemble forecasts made April 27 to July 20 with outcomes observed in the weeks ending May 23 through July 25, 2020 revealed precise short-term forecasts, with accuracy deteriorating at longer prediction horizons of up to four weeks. At all prediction horizons, the prediction intervals were well calibrated with 92-96% of observations falling within the rounded 95% prediction intervals. ConclusionsThis analysis demonstrates that real-time, publicly available ensemble forecasts issued in April-July 2020 provided robust short-term predictions of reported COVID-19 deaths in the United States. With the ongoing need for forecasts of impacts and resource needs for the COVID-19 response, the results underscore the importance of combining multiple probabilistic models and assessing forecast skill at different prediction horizons. Careful development, assessment, and communication of ensemble forecasts can provide reliable insight to public health decision makers.

The vaginal metabolome and microbiota of cervical HPV-positive and HPV-negative women: a cross-sectional analysis.

OBJECTIVE: Characterise the vaginal metabolome of cervical HPV-infected and uninfected women. DESIGN: Cross-sectional. SETTING: The Center for Health Behavior Research at the University of Maryland School of Public Health. SAMPLE: Thirty-nine participants, 13 categorised as HPV-negative and 26 as HPV-positive (any genotype; HPV+ ), 14 of whom were positive with at least one high-risk HPV strain (hrHPV). METHOD: Self-collected mid-vaginal swabs were profiled for bacterial composition by 16S rRNA gene amplicon sequencing, metabolites by both gas and liquid chromatography mass spectrometry, and 37 types of HPV DNA. MAIN OUTCOME MEASURES: Metabolite abundances. RESULTS: Vaginal microbiota clustered into Community State Type (CST) I (Lactobacillus crispatus-dominated), CST III (Lactobacillus iners-dominated), and CST IV (low-Lactobacillus, 'molecular-BV'). HPV+ women had higher biogenic amine and phospholipid concentrations compared with HPV- women after adjustment for CST and cigarette smoking. Metabolomic profiles of HPV+ and HPV- women differed in strata of CST. In CST III, there were higher concentrations of biogenic amines and glycogen-related metabolites in HPV+ women than in HPV- women. In CST IV, there were lower concentrations of glutathione, glycogen, and phospholipid-related metabolites in HPV+ participants than in HPV- participants. Across all CSTs, women with hrHPV strains had lower concentrations of amino acids, lipids, and peptides compared with women who had only low-risk HPV (lrHPV). CONCLUSIONS: The vaginal metabolome of HPV+ women differed from HPV- women in terms of several metabolites, including biogenic amines, glutathione, and lipid-related metabolites. If the temporal relation between increased levels of reduced glutathione and oxidised glutathione and HPV incidence/persistence is confirmed in future studies, anti-oxidant therapies may be considered as a non-surgical HPV control intervention. TWEETABLE ABSTRACT: Metabolomics study: Vaginal microenvironment of HPV+ women may be informative for non-surgical interventions.

Calculations for deep inelastic scattering using fast interpolation grid techniques at NNLO in QCD and the extraction of α s from HERA data.

The extension of interpolation-grid frameworks for perturbative QCD calculations at next-to-next-to-leading order (NNLO) is presented for deep inelastic scattering (DIS) processes. A fast and flexible evaluation of higher-order predictions for any a posteriori choice of parton distribution functions (PDFs) or value of the strong coupling constant is essential in iterative fitting procedures to extract PDFs and Standard Model parameters as well as for a detailed study of the scale dependence. The APPLfast project, described here, provides a generic interface between the parton-level Monte Carlo program NNLOjet and both the APPLgrid and fastNLO libraries for the production of interpolation grids at NNLO accuracy. Details of the interface for DIS processes are presented together with the required interpolation grids at NNLO, which are made available. They cover numerous inclusive jet measurements by the H1 and ZEUS experiments at HERA. An extraction of the strong coupling constant is performed as an application of the use of such grids and a best-fit value of α s ( M Z ) = 0.1170 ( 15 ) exp ( 25 ) th is obtained using the HERA inclusive jet cross section data.

Triple Differential Dijet Cross Section at the LHC.

The measurement of the triple-differential dijet production cross section as a function of the average transverse momentum p_{T,avg}, half the rapidity separation y^{*}, and the boost y_{b} of the two leading jets in the event enables a kinematical scan of the underlying parton momentum distributions. We compute for the first time the second-order perturbative QCD corrections to this triple-differential dijet cross section, at leading color in all partonic channels, thereby enabling precision studies with LHC dijet data. A detailed comparison with experimental CMS 8 TeV data is performed, demonstrating how the shape of this differential cross section probes the parton densities in different kinematical ranges.

Vector boson production in association with a jet at forward rapidities.

Final states with a vector boson and a hadronic jet allow one to infer the Born-level kinematics of the underlying hard scattering process, thereby probing the partonic structure of the colliding protons. At forward rapidities, the parton collisions are highly asymmetric and resolve the parton distributions at very large or very small momentum fractions, where they are less well constrained by other processes. Using theory predictions accurate to next-to-next-to-leading order (NNLO) in QCD for both W ± and Z production in association with a jet at large rapidities at the LHC, we perform a detailed phenomenological analysis of recent LHC measurements. The increased theory precision allows us to clearly identify specific kinematical regions where the description of the data is insufficient. By constructing ratios and asymmetries of these cross sections, we aim to identify possible origins of the deviations, and highlight the potential impact of the data on improved determinations of parton distributions.

Next-to-Next-to-Leading-Order QCD Corrections to the Transverse Momentum Distribution of Weak Gauge Bosons.

The transverse momentum spectra of weak gauge bosons and their ratios probe the underlying dynamics and are crucial in testing our understanding of the standard model. They are an essential ingredient in precision measurements, such as the W boson mass extraction. To fully exploit the potential of the LHC data, we compute the second-order [next-to-next-to-leading-order (NNLO)] QCD corrections to the inclusive-p_{T}^{W} spectrum as well as to the ratios of spectra for W^{-}/W^{+} and Z/W. We find that the inclusion of NNLO QCD corrections considerably improves the theoretical description of the experimental CMS data and results in a substantial reduction of the residual scale uncertainties.

Cigarette smoking is associated with an altered vaginal tract metabolomic profile.

Cigarette smoking has been associated with both the diagnosis of bacterial vaginosis (BV) and a vaginal microbiota lacking protective Lactobacillus spp. As the mechanism linking smoking with vaginal microbiota and BV is unclear, we sought to compare the vaginal metabolomes of smokers and non-smokers (17 smokers/19 non-smokers). Metabolomic profiles were determined by gas and liquid chromatography mass spectrometry in a cross-sectional study. Analysis of the 16S rRNA gene populations revealed samples clustered into three community state types (CSTs) ---- CST-I (L. crispatus-dominated), CST-III (L. iners-dominated) or CST-IV (low-Lactobacillus). We identified 607 metabolites, including 12 that differed significantly (q-value < 0.05) between smokers and non-smokers. Nicotine, and the breakdown metabolites cotinine and hydroxycotinine were substantially higher in smokers, as expected. Among women categorized to CST-IV, biogenic amines, including agmatine, cadaverine, putrescine, tryptamine and tyramine were substantially higher in smokers, while dipeptides were lower in smokers. These biogenic amines are known to affect the virulence of infective pathogens and contribute to vaginal malodor. Our data suggest that cigarette smoking is associated with differences in important vaginal metabolites, and women who smoke, and particularly women who are also depauperate for Lactobacillus spp., may have increased susceptibilities to urogenital infections and increased malodor.

Precise Predictions for Dijet Production at the LHC.

We present the calculation of dijet production, doubly differential in dijet mass m_{jj} and rapidity difference |y^{*}|, at leading color in all partonic channels at next-to-next-to-leading order (NNLO) in perturbative QCD. We consider the long-standing problems associated with scale choice for dijet production at next-to-leading order (NLO) and investigate the impact of including the NNLO contribution. We find that the NNLO theory provides reliable predictions, even when using scale choices that display pathological behavior at NLO. We choose the dijet invariant mass as the theoretical scale on the grounds of perturbative convergence and residual scale variation and compare the predictions to the ATLAS 7 TeV 4.5 fb^{-1} data.

Next-to-Next-to Leading Order QCD Predictions for Single Jet Inclusive Production at the LHC.

We report the first calculation of fully differential jet production at leading color in all partonic channels at next-to-next-to leading order in perturbative QCD and compare to the available ATLAS 7 TeV data. We discuss the size and shape of the perturbative corrections along with their associated scale variation across a wide range in jet transverse momentum, p_{T}, and rapidity, y. We find significant effects, especially at low p_{T}, and discuss the possible implications for parton distribution function fits.

Precise QCD Predictions for the Production of a Z Boson in Association with a Hadronic Jet.

We compute the cross section and differential distributions for the production of a Z boson in association with a hadronic jet to next-to-next-to-leading order (NNLO) in perturbative QCD, including the leptonic decay of the Z boson. We present numerical results for the transverse momentum and rapidity distributions of both the Z boson and the associated jet at the LHC. We find that the NNLO corrections increase the NLO predictions by approximately 1% and significantly reduce the scale variation uncertainty.

On the application of the tolerance factor to inorganic and hybrid halide perovskites: a revised system.

The tolerance factor is a widely used predictor of perovskite stability. The recent interest in hybrid perovskites for use as solar cell absorbers has lead to application of the tolerance factor to these materials as a way to explain and predict structure. Here we critically assess the suitability of the tolerance factor for halide perovskites. We show that the tolerance factor fails to accurately predict the stability of the 32 known inorganic iodide perovskites, and propose an alternative method. We introduce a revised set of ionic radii for cations that is anion dependent, this revision is necessary due to increased covalency in metal-halide bonds for heavier halides compared with the metal-oxide and fluoride bonds used to calculate Shannon radii. We also employ a 2D structural map to account for the size requirements of the halide anions. Together these measures yield a simple system which may assist in the search for new hybrid and inorganic perovskites.

Assessment of occupational radiation exposure in underground artisanal gold mines in Tongo, Upper East Region of Ghana.

Assessments of radon and gamma radiation levels were carried out in underground artisanal gold mines in Tongo. This is one of the numerous artisanal gold mining communities in Ghana. Solid State Nuclear Track Detectors (SSNTDs) were used to estimate the mean (222)Rn concentration and dose rates during the Harmattan season (November 2010 to February 2011). The values for the (222)Rn concentration at each monitoring site ranged from 14 ± 4 Bq m(-3) to 270 ± 9 Bq m(-3), with a mean value of 98 Bq m(-3). These measurements are well below the lower action level of 500 Bq m(-3) recommended by ICRP for workplaces. The activity concentrations of (40)K, (232)Th and (238)U were determined using gamma-ray spectroscopy method. The effective dose estimates of 0.11 ± 0.02 mSv y(-1) to 0.68 ± 0.04 mSv y(-1) were below the allowable limit of 20 mSv per annum for occupational exposure control recommended by the ICRP. The total annual effective dose varied from 0.22 ± 0.04 mSv y(-1) to 1.92 ± 0.08 mSv y(-1).