bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of anisotropy on the resonant scattering of Hydrogen atom from the fullerene C60
Authors: Dubey Km Akanksha , Srikanth Korutla , Rao T Rajagopala , Jose Jobin
Published: July 2020

From a macroscopic point of view, the C60 and the interaction offered by it is considered spherical because of its symmetry. However, the C60 is formed of hexagonal and pentagonal rings of Carbons. Therefore, on a microscopic level, the interaction potential offered in the elastic scattering of projectiles from the C60 is anisotropic. Elastic scattering of Hydrogen atom from the C60 with the interaction taken to be anisotropic is discussed in the present work. The complex radial and angular dependence of H-C60 interaction is calculated using the Density Functional Theory. The scattering resonances are seen to be modified to significant extent in comparison with the isotropic scattering case. However, the parameters of the non-resonant scattering are mostly unaffected due to the anisotropic effects.
Enhancing wildfire spread modelling by building a gridded fuel moisture content product with machine learning
Authors: McCandless Tyler C , Kosovic Branko , Petzke William
Published: July 2020

Wildland fire decision support systems require accurate predictions of wildland fire spread. Fuel moisture content (FMC) is one of the important parameters controlling the rate of spread of wildland fire. However, dead FMC measurements are provided by a relatively sparse network of remote automatic weather stations (RAWS), while live FMC is relatively infrequently measured manually. We developed a high resolution, gridded, real-time FMC data sets that did not previously exist for assimilation into operational wildland fire prediction systems based on ML. We used surface observations of live and dead FMC to train machine learning models to estimate FMC based on satellite observations. Moderate Resolution Imaging Spectrometer Terra and Aqua reflectances are used to predict the live and dead FMC measured by the Wildland Fire Assessment System and RAWS). We evaluate multiple machine learning methods including multiple linear regression, random forests (RFs), gradient boosted regression and artificial neural networks. The models are trained to learn the relationships between the satellite reflectances, surface weather and soil moisture observations and FMC. After training on data corresponding to the temporally and spatially nearest grid points to the irregularly spaced surface FMC observations, the machine learning models could be applied to all grid cells for a gridded product over the Conterminous United States (CONUS). The results show generally that the rule-based approaches have the lowest errors likely due to the sharp decision boundaries among the predictors, and the RF approach that utilizes bagging to avoid over-fitting has the lowest error on the test dataset. The errors are typically between 25%−33% the typical variability of the FMC data, which indicate the skill of the RF in estimating the FMC based on satellite data and surface characteristics. The FMC gridded product based on the RF runs operationally daily over CONUS and can be assimilated into WRF-Fire for more accurate wildland fire spread predictions.
Deprescribing in older people approaching end-of-life: development and validation of STOPPFrail version 2
Authors: Curtin Denis , Gallagher Paul , O’Mahony Denis
Published: July 2020

Background

Screening Tool of Older Persons Prescriptions in Frail adults with limited life expectancy (STOPPFrail) criteria were developed in 2017 to assist physicians with deprescribing decisions in older people approaching end-of-life. Updating was required to make the tool more practical, patient-centred and complete.

Methods

a thorough literature review was conducted to, first, devise a practical method for identifying older people who are likely to be approaching end-of-life, and second, reassess and update the existing deprescribing criteria. An eight-member panel with a wide-ranging experience in geriatric pharmacotherapy reviewed a new draft of STOPPFrail and were invited to propose new deprescribing criteria. STOPPFrail version 2 was then validated using Delphi consensus methodology.

Results

STOPPFrail version 2 emphasises the importance of shared decision-making in the deprescribing process. A new method for identifying older people who are likely to be approaching end-of-life is included along with 25 deprescribing criteria. Guidance relating to the deprescribing of antihypertensive therapies, anti-anginal medications and vitamin D preparations comprises the new criteria.

Conclusions

STOPPFrail criteria have been updated to assist physicians in efforts to reduce drug-related morbidity and burden for their frailest older patients. Version 2 is based on an up-to-date literature review and consensus validation by a panel of experts.
PhISCS-BnB: a fast branch and bound algorithm for the perfect tumor phylogeny reconstruction problem
Authors: Sadeqi Azer Erfan , Rashidi Mehrabadi Farid , Malikić Salem , Li Xuan Cindy , Bartok Osnat , Litchfield Kevin , Levy Ronen , Samuels Yardena , Schäffer Alejandro A , Gertz E Michael , Day Chi-Ping , Pérez-Guijarro Eva , Marie Kerrie , Lee Maxwell P , Merlino Glenn , Ergun Funda , Sahinalp S Cenk
Published: July 2020

Motivation

Recent advances in single-cell sequencing (SCS) offer an unprecedented insight into tumor emergence and evolution. Principled approaches to tumor phylogeny reconstruction via SCS data are typically based on general computational methods for solving an integer linear program, or a constraint satisfaction program, which, although guaranteeing convergence to the most likely solution, are very slow. Others based on Monte Carlo Markov Chain or alternative heuristics not only offer no such guarantee, but also are not faster in practice. As a result, novel methods that can scale up to handle the size and noise characteristics of emerging SCS data are highly desirable to fully utilize this technology.

Results

We introduce PhISCS-BnB (phylogeny inference using SCS via branch and bound), a branch and bound algorithm to compute the most likely perfect phylogeny on an input genotype matrix extracted from an SCS dataset. PhISCS-BnB not only offers an optimality guarantee, but is also 10–100 times faster than the best available methods on simulated tumor SCS data. We also applied PhISCS-BnB on a recently published large melanoma dataset derived from the sublineages of a cell line involving 20 clones with 2367 mutations, which returned the optimal tumor phylogeny in <4 h. The resulting phylogeny agrees with and extends the published results by providing a more detailed picture on the clonal evolution of the tumor.

Availability and implementation

https://github.com/algo-cancer/PhISCS-BnB.

Supplementary information

Supplementary data are available at Bioinformatics online.
Treerecs: an integrated phylogenetic tool, from sequences to reconciliations
Authors: Comte Nicolas , Morel Benoit , Hasić Damir , Guéguen Laurent , Boussau Bastien , Daubin Vincent , Penel Simon , Scornavacca Celine , Gouy Manolo , Stamatakis Alexandros , Tannier Eric , Parsons David P
Published: July 2020

Motivation

Gene and species tree reconciliation methods are used to interpret gene trees, root them and correct uncertainties that are due to scarcity of signal in multiple sequence alignments. So far, reconciliation tools have not been integrated in standard phylogenetic software and they either lack performance on certain functions, or usability for biologists.

Results

We present Treerecs, a phylogenetic software based on duplication-loss reconciliation. Treerecs is simple to install and to use. It is fast and versatile, has a graphic output, and can be used along with methods for phylogenetic inference on multiple alignments like PLL and Seaview.

Availability and implementation

Treerecs is open-source. Its source code (C++, AGPLv3) and manuals are available from https://project.inria.fr/treerecs/.
Sweeping the flies away: evidence from a fruit fly eradication program
Authors: Salazar Lina , Aramburu Julian , Agurto Marcos , Maffioli Alessandro , Fahsbender Jossie
Published: July 2020

This article evaluates the short-term impacts of a fruit fly integrated pest management program in Peru. Exploiting arbitrary variation in the program’s intervention borders, we use a geographical regression discontinuity design to identify the program’s effects on agricultural outcomes. Pre-treatment balance tests show that producer and farm-level pre-treatment characteristics evolve smoothly at the intervention border. Results indicate that farmers within treated areas improved pest knowledge and are more likely to implement prevention and control practices. Also, they increased fruit production and sales. Our findings are confirmed by placebo tests and are robust to alternative regression discontinuity bandwidths and polynomials.
Oesophageal Probe Evaluation in Radiofrequency Ablation of Atrial Fibrillation (OPERA): results from a prospective randomized trial
Authors: Schoene Katharina , Arya Arash , Grashoff Friederike , Knopp Helge , Weber Alexander , Lerche Matthias , König Sebastian , Hilbert Sebastian , Kircher Simon , Bertagnolli Livio , Dinov Borislav , Hindricks Gerhard , Halm Ulrich , Zachäus Markus , Sommer Philipp
Published: July 2020

Aims

The aim of the study was to determine the incidence of oesophageal lesions after radiofrequency ablation (RFA) of atrial fibrillation (AF) with or without the use of oesophageal temperature probes.

Methods and results

Two hundred patients were prospectively randomized into two groups: the OPERA+ group underwent RFA using oesophageal probes (SensiTherm™); the OPERA− group received RFA using fixed energy levels of 25 W at the posterior wall without an oesophageal probe. All patients underwent post-interventional endoscopy and Holter-electrocardiogram after 6 months. (Clinical.Trials.gov: NCT03246594). One hundred patients were randomized in OPERA+ and 100 patients in OPERA−. The drop-out rate was 10%. In total, 18/180 (10%) patients developed endoscopically diagnosed oesophageal lesions (EDEL). There was no difference between the groups with 10/90 (11%) EDEL in OPERA+ vs. 8/90 (9%) in OPERA− (P = 0.62). Despite the higher power delivered at the posterior wall in OPERA+ [28 ± 4 vs. 25 ± 2 W (P = 0.001)], the average EDEL size was equal [5.7 ± 2.6 vs. 4.5 ± 1.7 mm (P = 0.38)]. The peak temperature did not correlate with EDEL size. During follow-up, no patient died. Only one patient in OPERA− required a specific therapy for treatment of the lesion. Cumulative AF recurrence after 6 (3–13) months was 28/87 (32%) vs. 34/88 (39%), P = 0.541.

Conclusion

This first randomized study demonstrates that intraoesophageal temperature monitoring using the SensiTherm™ probe does not affect the probability of developing EDEL. The peak temperature measured by the thermoprobe seems not to correlate with the incidence of EDEL. Empiric energy reduction at the posterior wall did not affect the efficacy of the procedure.
Arrhythmic burden in patients with new-onset persistent left bundle branch block after transcatheter aortic valve replacement: 2-year results of the MARE study
Authors: Muntané-Carol Guillem , Urena Marina , Nombela-Franco Luis , Amat-Santos Ignacio , Kleiman Neal , Munoz-Garcia Antonio , Atienza Felipe , Serra Vicenç , Deyell Marc W , Veiga-Fernandez Gabriela , Masson Jean-Bernard , Canadas-Godoy Victoria , Himbert Dominique , Castrodeza Javier , Elizaga Jaime , Francisco Pascual Jaume , Webb John G , de la Torre Hernandez Jose M , Asmarats Lluis , Pelletier-Beaumont Emilie , Philippon Francois , Rodés-Cabau Josep
Published: July 2020

Aims

We determined the incidence and type of arrhythmias at 2-year follow-up in patients with new-onset persistent left bundle branch block (LBBB) following transcatheter aortic valve replacement (TAVR).

Methods and results

Multicentre prospective study including 103 consecutive patients with new-onset persistent LBBB post-TAVR (SAPIEN XT/3: 53; CoreValve/Evolut R: 50). An implantable cardiac monitor (Reveal XT, Reveal Linq) was implanted before hospital discharge and patients had continuous monitoring for up to 2 years. Arrhythmic events were adjudicated in a central core lab. 1836 new arrhythmic events (tachyarrhythmias: 1655 and bradyarrhythmias: 181) occurred at 2 years. Of these, 283 (15%) occurred beyond 1 year (tachyarrhythmias 212, bradyarrhythmias 71) in 33 (36%) patients, without differences between valve type. Most late (>1 year) arrhythmic events were asymptomatic (94%) and led to a treatment change in 17 (19%) patients. A total of 71 late bradyarrhythmias [high-degree atrioventricular block (HAVB): 3, severe bradycardia: 68] were detected in 17 (21%) patients. At 2 years, 18 (17%) patients had received a permanent pacemaker (PPM) or implantable cardiac-defibrillator. PPM implantation due to HAVB predominated in the early phase post-TAVR, with only 1 HAVB event requiring PPM implantation after 1 year.

Conclusion

Patients with new-onset LBBB post-TAVR exhibited a very high burden of arrhythmic events within the 2 years post-procedure. While new tachyarrhythmic events were homogeneously distributed over time, the vast majority of new HAVB episodes leading to PPM implantation occurred early after the procedure. These results should help to guide the management of this challenging group of patients. (clinicaltrials.gov: NCT02153307)
Prospective use of ablation index for the ablation of right ventricle outflow tract premature ventricular contractions: a proof of concept study
Authors: Gasperetti Alessio , Sicuso Rita , Dello Russo Antonio , Zucchelli Giulio , Saguner Ardan Muammer , Notarstefano Pasquale , Soldati Ezio , Bongiorni Maria Grazia , Della Rocca Domenico Giovanni , Mohanty Sanghamitra , Carbucicchio Corrado , Duru Firat , Di Biase Luigi , Natale Andrea , Tondo Claudio , Casella Michela
Published: July 2020

Aims

Radiofrequency catheter ablation (RFCA) represents an effective option for idiopathic premature ventricular contractions (PVCs) treatment. Ablation Index (AI) is a novel ablation marker incorporating RF power, contact force, and time of delivery into a single weighted formula. Data regarding AI-guided PVCs RFCA are currently lacking. Aim of the study was to compare AI-guided and standard RFCA outcomes in patients with PVCs originating from the right ventricle outflow tract (RVOT).

Methods and results

Consecutive patients undergoing AI-guided RFCA of RVOT idiopathic PVCs were prospectively enrolled. Radiofrequency catheter ablation was performed following per-protocol target cut-offs of AI, depending on targeted area (RVOT free wall AI cut-off: 590; RVOT septum AI cut-off: 610). A multi-centre cohort of propensity-matched (age, sex, ejection fraction, and PVC site) patients undergoing standard PVCs RFCA was used as a comparator. Sixty AI-guided patients (44.2 ± 18.0 years old, 58% male, left ventricular ejection fraction 56.2 ± 3.8%) were enrolled; 34 (57%) were ablated in RVOT septum and 26 (43%) patients in the RVOT free wall area. Propensity match with 60 non-AI-guided patients was performed. Acute outcomes and complications resulted comparable. At 6 months, arrhythmic recurrence was more common in non-AI-guided patients whether in general (28% vs. 7% P = 0.003) or by ablated area (RVOT free wall: 27% vs. 4%, P = 0.06; RVOT septum 29% vs. 9% P = 0.05). Ablation Index guidance was associated with improved survival from arrhythmic recurrence [overall odds ratio 6.61 (1.95–22.35), P = 0.001; RVOT septum 5.99 (1.21–29.65), P = 0.028; RVOT free wall 11.86 (1.12–124.78), P = 0.039].

Conclusion

Ablation Index-guidance in idiopathic PVCs ablation was associated with better arrhythmic outcomes at 6 months of follow-up.
Long-term cardiometabolic disease risk in women with PCOS: a systematic review and meta-analysis
Authors: Wekker V , van Dammen L , Koning A , Heida K Y , Painter R C , Limpens J , Laven J S E , Roeters van Lennep J E , Roseboom T J , Hoek A
Published: July 2020

BACKGROUND

Polycystic ovary syndrome (PCOS) is associated with cardiometabolic disease, but recent systematic reviews and meta-analyses of longitudinal studies that quantify these associations are lacking.

OBJECTIVE AND RATIONALE

Is PCOS a risk factor for cardiometabolic disease?

SEARCH METHODS

We searched from inception to September 2019 in MEDLINE and EMBASE using controlled terms (e.g. MESH) and text words for PCOS and cardiometabolic outcomes, including cardiovascular disease (CVD), stroke, myocardial infarction, hypertension (HT), type 2 diabetes (T2D), metabolic syndrome and dyslipidaemia. Cohort studies and case–control studies comparing the prevalence of T2D, HT, fatal or non-fatal CVD and/or lipid concentrations of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) between women with and without PCOS of ≥18 years of age were eligible for this systematic review and meta-analysis. Studies were eligible regardless of the degree to which they adjusted for confounders including obesity. Articles had to be written in English, German or Dutch. Intervention studies, animal studies, conference abstracts, studies with a follow-up duration less than 3 years and studies with less than 10 PCOS cases were excluded. Study selection, quality assessment (Newcastle–Ottawa Scale) and data extraction were performed by two independent researchers.

OUTCOMES

Of the 5971 identified records, 23 cohort studies were included in the current systematic review. Women with PCOS had increased risks of HT (risk ratio (RR): 1.75, 95% CI 1.42 to 2.15), T2D (RR: 3.00, 95% CI 2.56 to 3.51), a higher serum concentration of TC (mean difference (MD): 7.14 95% CI 1.58 to 12.70 mg/dl), a lower serum concentration of HDL-C (MD: −2.45 95% CI −4.51 to −0.38 mg/dl) and increased risks of non-fatal cerebrovascular disease events (RR: 1.41, 95% CI 1.02 to 1.94) compared to women without PCOS. No differences were found for LDL-C (MD: 3.32 95% CI −4.11 to 10.75 mg/dl), TG (MD 18.53 95% CI −0.58 to 37.64 mg/dl) or coronary disease events (RR: 1.78, 95% CI 0.99 to 3.23). No meta-analyses could be performed for fatal CVD events due to the paucity of mortality data.

WIDER IMPLICATIONS

Women with PCOS are at increased risk of cardiometabolic disease. This review quantifies this risk, which is important for clinicians to inform patients and to take into account in the cardiovascular risk assessment of women with PCOS. Future clinical trials are needed to assess the ability of cardiometabolic screening and management in women with PCOS to reduce future CVD morbidity.
Outcomes of patients diagnosed with COVID-19 in the early postoperative period following cardiac surgery
Authors: Yates Martin T , Balmforth Damian , Lopez-Marco Ana , Uppal Rakesh , Oo Aung Y
Published: July 2020

The coronavirus 2019 (COVID-19) pandemic has disrupted patient care across the NHS. Following the suspension of elective surgery, priority was placed in providing urgent and emergency surgery for patients with no alternative treatment. We aim to assess the outcomes of patients undergoing cardiac surgery who have COVID-19 infection diagnosed in the early postoperative period. We identified 9 patients who developed COVID-19 infection following cardiac surgery. These patients had a significant length of hospital stay and extremely poor outcomes with mortality of 44%. In conclusion, the outcome of cardiac surgical patients who contracted COVID-19 infection perioperatively is extremely poor. In order to offer cardiac surgery, units must implement rigorous protocols aimed at maintaining a COVID-19 protective environment to minimize additional life-threatening complications related to this virus infection.
Design of a partially premixed burner for biogas-fired wall-mounted boiler
Authors: Sun Mengxiao , Huang Xiaomei , Zhao Yi , Zhang Pengyuan , Zhou Yang
Published: July 2020

Biogas is deemed as one of the most promising renewable fuels emerging in the past several decades. At present, biogas is mainly applied to cooking for substituting fossil fuels. However, biogas is rarely reported to be used for space heating. In this paper, we designed a biogas-fired partially premixed burner for gas-fired wall-mounted boilers, which has the heat input of 25 kW and can be used for space heating and water heater tank heating. The reference gas was assumed as 60% of methane (CH4) and 40% of CO2, and the burner port area was designed as 4744.5 mm2 according to the calculation. Then, experiments were conducted to study the performance of this burner. Jet diameters were modified in order to investigate their effects on heat input, primary air ratio and flame stability of the burner. The results indicate that the burner shows superior performance when the jet diameter is 2.0 mm. Meanwhile, the primary air ratio (${\alpha}^{\prime }$) satisfies the design requirement. Moreover, a gas-fired wall-mounted boiler with this burner was examined to investigate the influence of different biogas composition on exhaust emissions and thermal efficiency. The results show that the concentration of CO in the flue gas meets the national standard when CH4 varied from 40% to 60% in the biogas. However, the thermal efficiency of the biogas-fired wall-mounted boiler reduces greatly with the increase of CH4 percentage.
A Chronic Murine Disease Model of Coccidioidomycosis Using Coccidioides posadasii, Strain 1038
Authors: Shubitz Lisa F , Powell Daniel A , Butkiewicz Christine D , Lewis M Lourdes , Trinh Hien T , Frelinger Jeffrey A , Orbach Marc J , Galgiani John N
Published: July 2020

Murine infections with most Coccidioides spp. strains are lethal by 3 weeks, limiting the study of immune responses. Coccidioides posadasii, strain 1038 (Cp1038), while slowly lethal, resulted in protracted survival of C57BL/6 (B6) mice. In resistant (B6D2)F1/J mice, lung fungal burdens stabilized by week 4 without progression through week 16, better modeling human coccidioidal infections after their immunologic control. Immunodeficient tumor necrosis factor (Tnf) α knockout (KO) and interferon (Ifn) γ receptor 1 (Ifn-γr1) KO mice survived a median of 22.5 and 34 days, compared with 70 days in B6 mice (P = .001 and P < .01, respectively), though 14-day lung fungal burden studies showed little difference between Ifn-γr1 KO and B6 mice. B6 mice showed peak concentrations of key inflammatory lung cytokines, including interleukin 6, 23, and 17A, Tnf-α, and Ifn-γ, only after 4 weeks of infection. The slower progression in B6 and the acquired fungal burden stability in B6D2 mice after Cp1038 infection greatly increases the array of possible immunologic studies.
Does Xylinas’ nomogram accurately predict intravesical recurrence risk after radical nephroureterectomy for primary upper urinary tract urothelial carcinoma when applied to Asian populations?
Authors: Lai Shicong , Wu Pengjie , Diao Tongxiang , Seery Samuel , Liu Jianyong , Hou Huimin , Liu Ming , Wang Jianye
Published: July 2020

Objective

To validate a prognostic nomogram (Xylinas’ nomogram) for intravesical recurrence after radical nephroureterectomy for primary upper urinary tract urothelial carcinoma patients of Asian descent.

Methods

Clinicopathological and survival data from 243 primary urinary tract urothelial carcinoma patients who underwent radical nephroureterectomy with bladder cuff excision between January 2004 and May 2017 were collated. Univariate and multivariable Cox regression analyses were performed to identify independent risk factors associated with intravesical recurrence-free survival. External validation was determined using regression coefficients abstracted from previously published data. Performance was then quantified through calibration and discrimination, according to concordance indexes (c-index) in receiver operating characteristic curves.

Results

163 patients met our eligibility criteria and were finally included in this study. At a median follow-up of 60 months, intravesical recurrence occurred in 29.4% (n = 48). Multivariable analysis revealed that being male, ureteral tumor location, tumor multifocality and previous bladder cancer were independent prognostic factors of intravesical recurrence-free survival. When Xylinas’ nomogram was applied to our cohort, the discriminatory power was found to be roughly equivalent with a c-index of 68.3% for the reduced model and 68.4% for the full model. Calibration plots also revealed intravesical recurrence predictions at 3, 6, 12, 18, 24 and 36 months had relative concordance. Contrasting the respective performances of the reduced and full model suggests there is no significant difference between the two (all P > 0.05).

Conclusions

This nomogram appears accurate at predicting intravesical recurrence after radical nephroureterectomy for primary urinary tract urothelial carcinoma in Asian populations. However, it remains necessary to data mine for unknown prognostic factors for optimization. Further external validation is required across larger, ethically diverse populations before applying this nomogram in clinical practice.
A Note on Chromy’s Sampling Procedure
Authors: Chauvet Guillaume
Published: July 2020

Chromy (1979) proposed an unequal probability sampling algorithm, which is the default sequential method used in the SURVEYSELECT procedure of the SAS software. In this article, we demonstrate that Chromy sampling is equivalent to pivotal sampling. This makes it possible to estimate the variance unbiasedly for the randomized version of the method programmed in the SURVEYSELECT procedure.
Binary black holes in the pair instability mass gap
Authors: Di Carlo Ugo N , Mapelli Michela , Bouffanais Yann , Giacobbo Nicola , Santoliquido Filippo , Bressan Alessandro , Spera Mario , Haardt Francesco
Published: July 2020

Pair instability (PI) and pulsational PI prevent the formation of black holes (BHs) with mass ≳60 M⊙ from single star evolution. Here, we investigate the possibility that BHs with mass in the PI gap form via stellar mergers and multiple stellar mergers, facilitated by dynamical encounters in young star clusters. We analyse 104 simulations, run with the direct N-body code nbody6++gpu coupled with the population synthesis code mobse. We find that up to ∼6 per cent of all simulated BHs have mass in the PI gap, depending on progenitor’s metallicity. This formation channel is strongly suppressed in metal-rich (Z = 0.02) star clusters because of stellar winds. BHs with mass in the PI gap are initially single BHs but can efficiently acquire companions through dynamical exchanges. We find that ∼21 per cent, 10 per cent, and 0.5 per cent of all binary BHs have at least one component in the PI mass gap at metallicity Z = 0.0002, 0.002, and 0.02, respectively. Based on the evolution of the cosmic star formation rate and metallicity, and under the assumption that all stars form in young star clusters, we predict that ∼5 per cent of all binary BH mergers detectable by advanced LIGO and Virgo at their design sensitivity have at least one component in the PI mass gap.
The magnetic obliquity of accreting T Tauri stars
Authors: McGinnis Pauline , Bouvier Jérôme , Gallet Florian
Published: July 2020

Classical T Tauri stars (CTTSs) accrete material from their discs through their magnetospheres. The geometry of the accretion flow strongly depends on the magnetic obliquity, i.e. the angle between the rotational and magnetic axes. We aim at deriving the distribution of magnetic obliquities in a sample of 10 CTTSs. For this, we monitored the radial velocity variations of the He i λ5876 Å line in these stars’ spectra along their rotational cycle. He i is produced in the accretion shock, close to the magnetic pole. When the magnetic and rotational axes are not aligned, the radial velocity of this line is modulated by stellar rotation. The amplitude of modulation is related to the star’s projected rotational velocity, vsin i, and the latitude of the hotspot. By deriving vsin i and He i λ5876 radial velocity curves from our spectra, we thus obtain an estimate of the magnetic obliquities. We find an average obliquity in our sample of 11.4° with an rms dispersion of 5.4°. The magnetic axis thus seems nearly, but not exactly aligned with the rotational axis in these accreting T Tauri stars, somewhat in disagreement with studies of spectropolarimetry, which have found a significant misalignment (≳20°) for several CTTSs. This could simply be an effect of low number statistics, or it may be due to a selection bias of our sample. We discuss possible biases that our sample may be subject to. We also find tentative evidence that the magnetic obliquity may vary according to the stellar interior and that there may be a significant difference between fully convective and partly radiative stars.
The SAMI–Fornax Dwarfs Survey I: sample, observations, and the specific stellar angular momentum of dwarf elliptical galaxies
Authors: Scott Nicholas , Eftekhari F Sara , Peletier Reynier F , Bryant Julia J , Bland-Hawthorn Joss , Capaccioli Massimo , Croom Scott M , Drinkwater Michael , Falcón-Barroso Jésus , Hilker Michael , Iodice Enrichetta , Lorente Nuria F P , Mieske Steffen , Spavone Marilena , van de Ven Glenn , Venhola Aku
Published: July 2020

Dwarf ellipticals are the most common galaxy type in cluster environments; however, the challenges associated with their observation mean that their formation mechanisms are still poorly understood. To address this, we present deep integral field observations of a sample of 31 low-mass (107.5 < M⋆ < 109.5 M⊙) early-type galaxies in the Fornax cluster with the SAMI instrument. For 21 galaxies, our observations are sufficiently deep to construct spatially resolved maps of the stellar velocity and velocity dispersion – for the remaining galaxies, we extract global velocities and dispersions from aperture spectra only. From the kinematic maps, we measure the specific stellar angular momentum λR of the lowest mass dE galaxies to date. Combining our observations with early-type galaxy data from the literature spanning a large range in stellar mass, we find that λR decreases towards lower stellar mass, with a corresponding increase in the proportion of slowly rotating galaxies in this regime. The decrease of λR with mass in our sample dE galaxies is consistent with a similar trend seen in somewhat more massive spiral galaxies from the CALIFA survey. This suggests that the degree of dynamical heating required to produce dEs from low-mass starforming progenitors may be relatively modest and consistent with a broad range of formation mechanisms.
On the survival of resonant and non-resonant planetary systems in star clusters
Authors: Stock Katja , Cai Maxwell X , Spurzem Rainer , Kouwenhoven M B N , Portegies Zwart Simon
Published: July 2020

Despite the discovery of thousands of exoplanets in recent years, the number of known exoplanets in star clusters remains tiny. This may be a consequence of close stellar encounters perturbing the dynamical evolution of planetary systems in these clusters. Here, we present the results from direct N-body simulations of multiplanetary systems embedded in star clusters containing N = 8k, 16k, 32k, and 64k stars. The planetary systems, which consist of the four Solar system giant planets Jupiter, Saturn, Uranus, and Neptune, are initialized in different orbital configurations, to study the effect of the system architecture on the dynamical evolution of the entire planetary system, and on the escape rate of the individual planets. We find that the current orbital parameters of the Solar system giants (with initially circular orbits, as well as with present-day eccentricities) and a slightly more compact configuration, have a high resilience against stellar perturbations. A configuration with initial mean-motion resonances of 3:2, 3:2, and 5:4 between the planets, which is inspired by the Nice model, and for which the two outermost planets are usually ejected within the first 105 yr, is in many cases stabilized due to the removal of the resonances by external stellar perturbation and by the rapid ejection of at least one planet. Assigning all planets the same mass of 1 MJup almost equalizes the survival fractions. Our simulations reproduce the broad diversity amongst observed exoplanet systems. We find not only many very wide and/or eccentric orbits, but also a significant number of (stable) retrograde orbits.
SRG/eROSITA uncovers the most X-ray luminous quasar at z > 6
Authors: Medvedev P , Sazonov S , Gilfanov M , Burenin R , Khorunzhev G , Meshcheryakov A , Sunyaev R , Bikmaev I , Irtuganov E
Published: July 2020

We report the discovery of X-ray emission from CFHQS J142952+544717, the most distant known radio-loud quasar at z = 6.18, on 2019 December 10–11 with the eROSITA telescope on board the SRG satellite during its ongoing all-sky survey. The object was identified by cross-matching an intermediate SRG/eROSITA source catalogue with the Pan-STARRS1 distant quasar sample at 5.6 < z < 6.7. The measured flux ∼8 × 10−14 erg cm−2 s−1 in the 0.3–2 keV energy band corresponds to an X-ray luminosity of $2.6^{+1.7}_{-1.0}\times 10^{46}$ erg s−1 in the 2–10 keV rest-frame energy band, which renders CFHQS J142952+544717 the most X-ray luminous quasar ever observed at z > 6. Combining our X-ray measurements with archival and new photometric measurements in other wavebands (radio to optical), we estimate the bolometric luminosity of this quasar at ∼(2–3) × 1047 erg s−1. Assuming Eddington limited accretion and isotropic emission, we infer a lower limit on the mass of the supermassive black hole of ∼2 × 109 M⊙. The most salient feature of CFHQS J142952+544717 is its X-ray brightness relative to the optical/UV emission. We argue that it may be linked to its radio-loudness (although the object is not a blazar according to its radio properties), specifically to a contribution of inverse Compton scattering of cosmic microwave background photons off relativistic electrons in the jets. If so, CFHQS J142952+544717 might be the tip of the iceberg of high-z quasars with enhanced X-ray emission, and SRG/eROSITA may find many more such objects during its 4-yr all-sky survey.
Spatiotemporal Genetic Diversity of Lions Reveals the Influence of Habitat Fragmentation across Africa
Authors: Curry Caitlin J , Davis Brian W , Bertola Laura D , White Paula A , Murphy William J , Derr James N
Published: July 2020

Direct comparisons between historical and contemporary populations allow for detecting changes in genetic diversity through time and assessment of the impact of habitat fragmentation. Here, we determined the genetic architecture of both historical and modern lions to document changes in genetic diversity over the last century. We surveyed microsatellite and mitochondrial genome variation from 143 high-quality museum specimens of known provenance, allowing us to directly compare this information with data from several recently published nuclear and mitochondrial studies. Our results provide evidence for male-mediated gene flow and recent isolation of local subpopulations, likely due to habitat fragmentation. Nuclear markers showed a significant decrease in genetic diversity from the historical (HE = 0.833) to the modern (HE = 0.796) populations, whereas mitochondrial genetic diversity was maintained (Hd = 0.98 for both). Although the historical population appears to have been panmictic based on nDNA data, hierarchical structure analysis identified four tiers of genetic structure in modern populations and was able to detect most sampling locations. Mitogenome analyses identified four clusters: Southern, Mixed, Eastern, and Western and were consistent between modern and historically sampled haplotypes. Within the last century, habitat fragmentation caused lion subpopulations to become more geographically isolated as human expansion changed the African landscape. This resulted in an increase in fine-scale nuclear genetic structure and loss of genetic diversity as lion subpopulations became more differentiated, whereas mitochondrial structure and diversity were maintained over time.
Development of a gene expression–based prognostic signature for IDH wild-type glioblastoma
Authors: Johnson Radia M , Phillips Heidi S , Bais Carlos , Brennan Cameron W , Cloughesy Timothy F , Daemen Anneleen , Herrlinger Ulrich , Jenkins Robert B , Lai Albert , Mancao Christoph , Weller Michael , Wick Wolfgang , Bourgon Richard , Garcia Josep
Published: July 2020

Background

We aimed to develop a gene expression–based prognostic signature for isocitrate dehydrogenase (IDH) wild-type glioblastoma using clinical trial datasets representative of glioblastoma clinical trial populations.

Methods

Samples were collected from newly diagnosed patients with IDH wild-type glioblastoma in the ARTE, TAMIGA, EORTC 26101 (referred to as “ATE”), AVAglio, and GLARIUS trials, or treated at UCLA. Transcriptional profiling was achieved with the NanoString gene expression platform. To identify genes prognostic for overall survival (OS), we built an elastic net penalized Cox proportional hazards regression model using the discovery ATE dataset. For validation in independent datasets (AVAglio, GLARIUS, UCLA), we combined elastic net–selected genes into a robust z-score signature (ATE score) to overcome gene expression platform differences between discovery and validation cohorts.

Results

NanoString data were available from 512 patients in the ATE dataset. Elastic net identified a prognostic signature of 9 genes (CHEK1, GPR17, IGF2BP3, MGMT, MTHFD1L, PTRH2, SOX11, S100A9, and TFRC). Translating weighted elastic net scores to the ATE score conserved the prognostic value of the genes. The ATE score was prognostic for OS in the ATE dataset (P < 0.0001), as expected, and in the validation cohorts (AVAglio, P < 0.0001; GLARIUS, P = 0.02; UCLA, P = 0.004). The ATE score remained prognostic following adjustment for O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status and corticosteroid use at baseline. A positive correlation between ATE score and proneural/proliferative subtypes was observed in patients with MGMT non-methylated promoter status.

Conclusions

The ATE score showed prognostic value and may enable clinical trial stratification for IDH wild-type glioblastoma.
Value of dynamic contrast perfusion MRI to predict early response to bevacizumab in newly diagnosed glioblastoma: results from ACRIN 6686 multicenter trial
Authors: Schmainda Kathleen M , Prah Melissa A , Marques Helga , Kim Eunhee , Barboriak Daniel P , Boxerman Jerrold L
Published: July 2020

Background

In Radiation Therapy Oncology Group (RTOG) 0825, a phase III trial of standard therapy with bevacizumab or without (placebo) in newly diagnosed glioblastoma, 44 patients underwent dynamic contrast enhanced (DCE) and/or dynamic susceptibility contrast (DSC) MRI in the American College of Radiology Imaging Network (ACRIN) trial 6686. The association between early changes in relative cerebral blood volume (rCBV) and volume transfer constant (Ktrans) with overall survival (OS) was evaluated.

Methods

MRI was performed at postop baseline (S0), immediately before (S1), 1 day after (S2), and 7 weeks after (S3) bevacizumab or placebo initiation. Mean normalized and standardized rCBV (nRCBV, sRCBV) and Ktrans were measured within contrast-enhancing lesion. Wilcoxon rank sum tests compared parameter changes from S1–S2 and S1–S3. Association with OS and progression-free survival (PFS) were determined using Kaplan–Meier and log-rank tests. Treatment response for groups stratified by pretreatment nRCBV (S0, S1) was explored. The intraclass correlation coefficient and repeatability coefficient for the placebo arm (S1–S2) were used to assess repeatability.

Results

Evaluable were 27–36 datasets per time point. Significant differences between treatment arms were found for changes in nRCBV and sRCBV from S1–S2 and S1–S3, and in Ktrans for S1–S3. Improved PFS (P = 0.05) but not OS (P = 0.46) was observed. High pretreatment rCBV predicted improved OS for bevacizumab-treated patients. Based on the intraclass correlation coefficient, sRCBV (0.92) was more repeatable than nRCBV (0.71) and Ktrans (0.75), consistent with repeatability coefficient values.

Conclusions

Bevacizumab significantly changes rCBV but not Ktrans as early as 1 day posttreatment in newly diagnosed glioblastoma unrelated to outcomes. Improvements in clinical trial design to maximize rCBV benefit are indicated.
Learning Delegation Through Role-Play: A Problem-Based Learning Activity for Nursing Students
Authors: Seibert Susan A.
Published: July 2020

According to the American Nurses Association and National Council of State Boards of Nursing 2019 guidelines, teaching strategies are needed to engage students in the application of delegation knowledge and skills. Students need opportunities to gain experience with delegation decision-making in a safe, risk-free environment. This article describes the instructional design and evaluation of an innovative role-play activity to engage senior-level nursing students in delegation decision-making.
Suicide Behavior Following PHQ-9 Screening Among Individuals With Substance Use Disorders
Authors: Yarborough Bobbi Jo H. , Stumbo Scott P. , Ahmedani Brian , Rossom Rebecca , Coleman Karen , Boggs Jennifer M. , Simon Gregory E.
Published: July 2020

Objectives:

Individuals with substance use disorders (SUD) are at risk for suicide, but no studies have assessed whether routinely administered screeners for suicidal ideation accurately identify outpatients with SUD who are at risk for suicide attempt or death.

Methods:

Data from more than 186,000 visits by over 55,000 patients with mental health and SUD diagnoses receiving care in 7 health systems were analyzed to determine whether responses to item 9 of the 9-item Patient Health Questionnaire, which assesses frequency of thoughts of death and self-harm, are associated with suicide outcomes after an outpatient visit. Odds of suicide attempt or death were computed using generalized estimating equations.

Results:

In bivariate analyses, a nearly 5-fold risk was observed for patients answering “nearly every day” relative to “not at all” among individuals who made a suicide attempt within 90 days (4.9% vs 1.1%; χ2 = 1151, P < 0.0001). At nearly half of visits (46%) followed by a suicide attempt within 90 days, patients responded “not at all.” In logistic models, compared to “not at all,” all other responses were associated with higher odds of suicide attempt or death within 90 days. Fully adjusted models attenuated results but odds of suicide attempt (AOR = 3.24, CI: 2.69–3.91) and suicide death (AOR = 5.67, CI: 2.0–16.1) remained high for those reporting “nearly every day.”

Conclusions:

In people with SUD, increasing Patient Health Questionnaire item 9 response predicts increased risk of subsequent suicidal behavior and should prompt intervention. However, clinicians should realize that those reporting “not at all” are not immune from subsequent suicide risk.
The Prevalence of Smartphones and WeChat Use Among Older Adults With Chronic Disease in a Western China
Authors: Zhang Lifang , Wei GuiYuan , Xu Zhifang , Huang Qiuhuan , Liu Guojun
Published: July 2020

Telemedicine is a promising way to deliver patient education and health services, but access to information technology among potential patients is a prerequisite. This study surveyed the prevalence of smartphone use and the use of the Chinese social networking platform WeChat and Wi-Fi access in the homes of older adults in a western area of China. A convenience sample of 225 older adults with chronic diseases in two tertiary hospitals was interviewed regarding smartphone ownership, WeChat use, and access to Wi-Fi at home. Participant ability in performing the activities of daily living was also assessed. Logistic regressions were used to analyze the independently associated factors of smartphone ownership, WeChat use, and Wi-Fi access at home. The results show that the prevalence of smartphone use was 19.6%, only 8.9% of those surveyed used WeChat, but 39.6% had access to Wi-Fi at home. Education level was the only factor significantly associated with the three dependent variables. Ability in performing activities of daily living was positively correlated with access to Wi-Fi at home (odds ratio, 2.549; P = .011). It will be difficult to implement telemedicine through smartphones in such relatively poor areas of China. Better-educated older adults who are less dependent in performing activities of daily living are potential users of telemedicine.
Recent Trends and Overall Survival of Young Versus Older Adults With Stage II to III Rectal Cancer Treated With and Without Surgery in the United States, 2010-2015
Authors: Sanford Nina N. , Dee Edward C. , Ahn Chul , Kazmi Syed A. , Beg Muhammad S. , Folkert Michael R. , Aguilera Todd A. , Polanco Patricio M. , Pogacnik Javier S. , Sher David J.
Published: July 2020

Background:

The omission of surgery via nonoperative management (NOM) for rectal cancer may be increasing, and this strategy could be particularly attractive for younger patients, whose incidence of rectal cancer has been rising. We sought to assess trends in NOM in young (younger than 55 y) versus older adult (55 y and older) rectal cancer cohorts.

Methods:

The National Cancer Database was used to identify patients diagnosed with stage II to III rectal cancer between 2010 and 2015. Multivariable logistic regression defined the association between sociodemographic variables and odds of NOM, including an age (18 to 54 vs. 55+ y)×surgery (surgery vs. NOM) interaction term. Adjusted Cox regression models compared overall survival between NOM versus surgery.

Results:

Among 22,561 patients with a median follow-up of 37.5 months, the utilization rate of NOM increased from 10.7% (2010) to 15.2% (2015). Older patients were more likely to receive NOM, although rates also increased among young (7.1% to 10.6%). Black patients were also more likely to receive NOM (P<0.001). Among the entire cohort, NOM was associated with worse overall survival (adjusted hazard ratio [AHR]=2.90, 95% confidence interval [CI]: 2.67-3.15) and there was a statistically significant age×NOM interaction (P=0.01) such that the effect of NOM on survival was worse for younger (AHR=3.37, 95% CI: 2.82-4.02) as compared with older patients (AHR=2.49, 95% CI: 2.27-2.74).

Conclusions:

The increasing trend for NOM in stage II to III rectal cancer may be driven by disparities in treatment. Management with NOM appears to be associated with poorer survival, particularly in younger patients and could worsen outcomes for groups already at risk for suboptimal cancer care.