bluuebunny/crossref_metadata_2025_split huggingface dataset:
The advection-dominated accretion flow for the anticorrelation between the X-ray photon index and the X-ray luminosity in neutron star low-mass X-ray binaries
Authors: Qiao Erlin , Liu B F 
Published: June 2020

ABSTRACT
Observationally, an anticorrelation between the X-ray photon index Γ (obtained by fitting the X-ray spectrum between 0.5 and 10 keV with a single power law) and the X-ray luminosity L0.5-10 keV, i.e. a softening of the X-ray spectrum with decreasing L0.5-10 keV, is found in neutron star low-mass X-ray binaries (NS-LMXBs) in the range of $L_{\rm 0.5\!-\!10\,keV}\sim 10^{34}\!-\!10^{36}\ \rm erg\ s^{-1}$. In this paper, we explain the observed anticorrelation between Γ and L0.5–10 keV within the framework of the self-similar solution of the advection-dominated accretion flow (ADAF) around a weakly magnetized NS. The ADAF model intrinsically predicts an anticorrelation between Γ and L0.5–10 keV. In the ADAF model, there is a key parameter, fth, which describes the fraction of the ADAF energy released at the surface of the NS as thermal emission to be scattered in the ADAF. We test the effect of fth on the anticorrelation between Γ and L0.5–10 keV. It is found that the value of fth can significantly affect the anticorrelation between Γ and L0.5–10 keV. Specifically, the anticorrelation between Γ and L0.5–10 keV becomes flatter with decreasing fth as taking fth = 0.1, 0.03, 0.01, 0.005, 0.003, and 0, respectively. By comparing with a sample of non-pulsating NS-LMXBs with well measured Γ and L0.5–10 keV, we find that indeed only a small value of 0.003 ≲ fth ≲ 0.1 is needed to match the observed anticorrelation between Γ and L0.5–10 keV. Finally, we argue that the small value of fth ≲ 0.1 derived in this paper further confirms our previous conclusion that the radiative efficiency of NSs with an ADAF accretion may not be as high as $\epsilon \sim {\dot{M} GM\over R_{*}}/{\dot{M} c^2}\sim 0.2$.
Predicting the time variation of radio emission from MHD simulations of a flaring T-Tauri star
Authors: Waterfall C O G , Browning P K , Fuller G A , Gordovskyy M , Orlando S , Reale F 
Published: June 2020

ABSTRACT
We model the time-dependent radio emission from a disc accretion event in a T-Tauri star using 3D, ideal magnetohydrodynamic simulations combined with a gyrosynchrotron emission and radiative transfer model. We predict for the first time, the multifrequency (1–1000 GHz) intensity and circular polarization from a flaring T-Tauri star. A flux tube, connecting the star with its circumstellar disc, is populated with a distribution of non-thermal electrons that is allowed to decay exponentially after a heating event in the disc and the system is allowed to evolve. The energy distribution of the electrons, as well as the non-thermal power-law index and loss rate, are varied to see their effect on the overall flux. Spectra are generated from different lines of sight, giving different views of the flux tube and disc. The peak flux typically occurs around 20–30 GHz and the radio luminosity is consistent with that observed from T-Tauri stars. For all simulations, the peak flux is found to decrease and move to lower frequencies with elapsing time. The frequency-dependent circular polarization can reach 10$-30{{\ \rm per\ cent}}$ but has a complex structure that evolves as the flare evolves. Our models show that observations of the evolution of the spectrum and its polarization can provide important constraints on physical properties of the flaring environment and associated accretion event.
The Bardeen–Petterson effect in accreting supermassive black hole binaries: a systematic approach
Authors: Gerosa Davide , Rosotti Giovanni , Barbieri Riccardo 
Published: June 2020

ABSTRACT
Disc-driven migration is a key evolutionary stage of supermassive black hole binaries hosted in gas-rich galaxies. Besides promoting the inspiral, viscous interactions tend to align the spins of the black holes with the orbital angular momentum of the disc. We present a critical and systematic investigation of this problem, also known as the Bardeen–Petterson effect. We design a new iterative scheme to solve the non-linear dynamics of warped accretion discs under the influence of both relativistic frame dragging and binary companion. We characterize the impact of the disc ‘critical obliquity’, which marks regions of the parameter space where stationary solutions do not exist. We find that black hole spins reach either complete alignment or a critical configuration. Reaching the critical obliquity might imply that the disc breaks as observed in hydrodynamical simulations. Our findings are important to predict the spin configurations with which supermassive black hole binaries enter their gravitational-wave driven regime and become detectable by LISA.
Consequences of Stability-Induced Epistasis for Substitution Rates
Authors: Youssef Noor , Susko Edward , Bielawski Joseph P 
Published: June 2020

AbstractDo interactions between residues in a protein (i.e., epistasis) significantly alter evolutionary dynamics? If so, what consequences might they have on inference from traditional codon substitution models which assume site-independence for the sake of computational tractability? To investigate the effects of epistasis on substitution rates, we employed a mechanistic mutation-selection model in conjunction with a fitness framework derived from protein stability. We refer to this as the stability-informed site-dependent (S-SD) model and developed a new stability-informed site-independent (S-SI) model that captures the average effect of stability constraints on individual sites of a protein. Comparison of S-SI and S-SD offers a novel and direct method for investigating the consequences of stability-induced epistasis on protein evolution. We developed S-SI and S-SD models for three natural proteins and showed that they generate sequences consistent with real alignments. Our analyses revealed that epistasis tends to increase substitution rates compared with the rates under site-independent evolution. We then assessed the epistatic sensitivity of individual site and discovered a counterintuitive effect: Highly connected sites were less influenced by epistasis relative to exposed sites. Lastly, we show that, despite the unrealistic assumptions, traditional models perform comparably well in the presence and absence of epistasis and provide reasonable summaries of average selection intensities. We conclude that epistatic models are critical to understanding protein evolutionary dynamics, but epistasis might not be required for reasonable inference of selection pressure when averaging over time and sites.
ENSO and Southeast Asian biomass burning modulate subtropical trans-Pacific ozone transport
Authors: Xue Lian , Ding Aijun , Cooper Owen , Huang Xin , Wang Wuke , Zhou Derong , Wu Zhaohua , McClure-Begley Audra , Petropavlovskikh Irina , Andreae Meinrat O , Fu Congbin 
Published: June 2020

Abstract
Trans-Pacific transport of enhanced ozone plumes has been mainly attributed to fossil fuel combustion in Asia in spring, but less attention has been paid to vegetation fires in Asia. Here we show that the El Niño-Southern Oscillation (ENSO)-modulated fires in Southeast Asia, rather than Asian fossil fuel plumes, dominate the interannual variability of springtime trans-Pacific transport of ozone across the entire North Pacific Ocean. During El Niño springs, the intensified fires from both the Indochinese Peninsula and Indonesia, together with large-scale circulation anomalies, result in enhanced ozone plumes that stretch over 15 000 km in both the lower-middle and upper troposphere. This enhancement is also observed in the in situ measurements of ozone concentration, with an almost 10% increase at Mauna Loa Observatory, Hawaii, a unique site to monitor the long-distance transport over the North Pacific. This study reports an unexpectedly strong influence of vegetation fires, linked with climate variability, on global tropospheric chemistry and proves once more how complex the interactions in the climate system are.
Endovascular Management of Intracranial Vertebral Artery Dissection: Technical Nuances for the Preservation of Posterior Inferior Cerebellar Artery and Basilar Artery
Authors: Gupta Gaurav , Eckstein Donna A , Narayan Vinayak , Jumah Fareed , DePalma Anthony A , Sozio Stephen J , Prendergast Nancy , Schonfeld Steven , Keller Irwin , Al-Mufti Fawaz , Nosko Michael , Nanda Anil , Roychowdhury Sudipta 
Published: June 2020

Abstract

BACKGROUND
The treatment of intracranial vertebral artery dissection (VAD) can be challenging.

OBJECTIVE
To evaluate the clinical presentation, endovascular treatment techniques, and prognostic outcome of patients diagnosed with intracranial VAD at our institution.

METHODS
A retrospective analysis of 35 patients who were diagnosed with VAD at our institution over 17-yr period (2001-2017) is presented. A total of 27 patients with a total of 30 affected arteries underwent endovascular treatment, and their outcome was evaluated.

RESULTS
Of the 35 total patients with VAD, 15 presented with headache, 12 with focal neurological deficits, 2 with neck pain, 2 with dizziness, 1 with syncope, and 3 after trauma. Of the 30 dissected arteries, 18 were treated with deconstruction and 12 were treated with stent reconstruction. Treatment method was determined by the dominance of the affected artery and location relative to the ipsilateral posterior inferior cerebellar artery (PICA) and the basilar artery. Deconstructive techniques were utilized in all cases of hypoplastic artery dissection and the majority of codominant artery dissections, whereas reconstruction was performed on the majority of dominant artery dissections. Rupture did not impact treatment technique. Four patients demonstrated post-treatment infarcts, and another 1 patient died because of intraparenchymal bleed. The remaining 22 patients demonstrated favorable clinical outcome. None of the patients developed recanalization or needed retreatment till the last follow-up.

CONCLUSION
This study suggests that endovascular treatment of intracranial VAD with deconstruction or stent reconstruction based on the patients anatomy, particularly vessel dominance and location with respect to PICA, is feasible and effective though the revascularization procedures still has its role in selected cases.
Reduction of Postoperative Opioid Use After Elective Spine and Peripheral Nerve Surgery Using an Enhanced Recovery After Surgery Program
Authors: Flanders Tracy M , Ifrach Joseph , Sinha Saurabh , Joshi Disha S , Ozturk Ali K , Malhotra Neil R , Pessoa Rachel , Kallan Michael J , Fleisher Lee A , Ashburn Michael A , Maloney Eileen , Welch William C , Ali Zarina S 
Published: June 2020

Abstract

Objective
Enhanced recovery after surgery (ERAS) pathways have previously been shown to be feasible and safe in elective spinal procedures. As publications on ERAS pathways have recently emerged in elective neurosurgery, long-term outcomes are limited. We report on our 18-month experience with an ERAS pathway in elective spinal surgery.

Methods
A historical cohort of 149 consecutive patients was identified as the control group, and 1,141 patients were prospectively enrolled in an ERAS protocol. The primary outcome was the need for opioid use one month postoperation. Secondary outcomes were opioid and nonopioid consumption on postoperative day (POD) 1, opioid use at three and six months postoperation, inpatient pain scores, patient satisfaction scores, postoperative Foley catheter use, mobilization/ambulation on POD0–1, length of stay, complications, and intensive care unit admissions.

Results
There was significant reduction in use of opioids at one, three, and six months postoperation (38.6% vs 70.5%, P &lt; 0.001, 36.5% vs 70.9%, P &lt; 0.001, and 23.6% vs 51.9%, P = 0.008) respectively. Both groups had similar surgical procedures and demographics. PCA use was nearly eliminated in the ERAS group (1.4% vs 61.6%, P &lt; 0.001). ERAS patients mobilized faster on POD0 compared with control (63.5% vs 20.7%, P &lt; 0.001). Fewer patients in the ERAS group required postoperative catheterization (40.7% vs 32.7%, P &lt; 0.001). The ERAS group also had decreased length of stay (3.4 vs 3.9 days, P = 0.020).

Conclusions
ERAS protocols for all elective spine and peripheral nerve procedures are both possible and effective. This standardized approach to patient care decreases opioid usage, eliminates the use of PCAs, mobilizes patients faster, and reduces length of stay.
Perceptual Experience and Degrees of Belief
Authors: Raleigh Thomas , Vindrola Filippo 
Published: June 2020

AbstractAccording to the recent Perceptual Confidence view, perceptual experiences possess not only a representational content, but also a degree of confidence in that content. The motivations for this view are partly phenomenological and partly epistemic. We discuss both the phenomenological and epistemic motivations for the view, and the resulting account of the interface between perceptual experiences and degrees of belief. We conclude that, in their present state of development, orthodox accounts of perceptual experience are still to be favoured over the perceptual confidence view.
The Effect of Institutional Affiliation and Career Patterns on (De)centralization Preferences in Advanced Multi-Level States: Parliamentarians’ Support for (De)Centralization in Belgium
Authors: Dodeigne Jeremy , Niessen Christoph , Reuchamps Min , Sinardet Dave 
Published: June 2020

AbstractThe decentralization of political power towards subnational entities is one of the major contemporary processes of territorial transformation in European democracies. Traditionally, research has focused on arguments related to nationalism and identities. Later, the strategic agency of political parties has been integrated as they typically play a major role in negotiating constitutional reforms. We investigate two institutionalist factors to explain why political Parliamentarians (MPs) favour decentralization while others oppose it: their parliamentary institutional affiliation and their career pattern (as well as the interaction between both). The importance of these factors is studied based on a large-scale survey among Belgian MPs from all federal and regional parliaments. Our results indicate that MPs’ preferences for decentralization significantly differ depending on their institutional affiliation (regional MPs being more decentralist than national MPs). This difference is moderated by MPs’ career pattern, but only for national MPs (who are more decentralist when they have a regional career pattern).
Phenotypic Characterization of Targeted Knockdown of Cyclin-Dependent Kinases in the Intestinal Epithelial Cells
Authors: Lu Shuyan , Sung Tae , Amaro Marina , Hirakawa Brad , Jessen Bart , Hu Wenyue 
Published: June 2020

Abstract
Cyclin-dependent kinases (CDKs) are serine/threonine kinases that regulate cell cycle and have been vigorously pursued as druggable targets for cancer. There are over 20 members of the CDK family. Given their structural similarity, selective inhibition by small molecules has been elusive. In addition, collateral damage to highly proliferative normal cells by CDK inhibitors remains a safety concern. Intestinal epithelial cells are highly proliferative and the impact of individual CDK inhibition on intestinal cell proliferation has not been well studied. Using the rat intestinal epithelial (IEC6) cells as an in vitro model, we found that the selective CDK4/6 inhibitor palbociclib lacked potent anti-proliferative activity in IEC6 relative to the breast cancer cell line MCF7, indicating the absence of intestinal cell reliance on CDK4/6 for cell cycle progression. To further illustrate the role of CDKs in intestinal cells, we chose common targets of CDK inhibitors (CDK 1, 2, 4, 6, and 9) for targeted gene knockdown to evaluate phenotypes. Surprisingly, only CDK1 and CDK9 knockdown demonstrated profound cell death or had moderate growth effects, respectively. CDK2, 4, or 6 knockdowns, whether single, double, or triple combinations, did not have substantial impact. Studies evaluating CDK1 knockdown under various cell seeding densities indicate direct effects on viability independent of proliferation state and imply a potential noncanonical role for CDK1 in intestinal epithelial biology. This research supports the concept that CDK1 and CDK9, but not CDKs 2, 4, or 6, are essential for intestinal cell cycle progression and provides safety confidence for interphase CDK inhibition.
Soft drugs in anesthesia: remifentanil as prototype to modern anesthetic drug development
Authors: Birgenheier Nathaniel M. , Stuart Ami R. , Egan Talmage D. 
Published: June 2020

Purpose of review
The unique demands of modern anesthesia practice require that medications be effective, well tolerated, and efficient. These attributes are increasingly achieved with the soft drug approach, wherein novel active compounds are specifically designed to be susceptible to rapid biotransformation to inactive metabolites. The present review summarizes the historical background and recent trends in soft drug development in anesthesiology.

Recent findings
Soft drug development programs for propranadid, etomidate, and benzodiazepine analogues have been undertaken in recent years. Although all three drugs advanced into human trials, neuro-excitatory adverse effects hampered the propranadid and etomidate analogue projects. Remimazolam, the soft benzodiazepine analogue, is at an advanced stage of development, having already received regulatory approval or review in several countries.

Summary
With succinylcholine as the historical forerunner and remifentanil as the modern prototype, the soft drug paradigm continues to hold promise for the future of anesthesia drug development.
The role of pharmacokinetics and pharmacodynamics in clinical anaesthesia practice
Authors: Hannivoort Laura N. , Absalom Anthony R. , Struys Michel M.R.F. 
Published: June 2020

Purpose of review
Growing concerns about the environmental effects of volatile anaesthetics are likely to lead to increased use of intravenous anaesthetic drugs. Pharmacokinetic/pharmacodynamic (PKPD) models can increase the accuracy of intravenous drug titration, especially in populations that differ from the ‘average.’ However, with a growing number of PKPD models, and other technology available to date, it can be hard to see the wood for the trees. This review attempts to guide the reader through the PKPD jungle.

Recent findings
General purpose PKPD models for propofol and remifentanil designed to apply to a broader population, including children, the elderly and the obese, reduce the need for population-specific models. PKPD models for drugs such as dexmedetomidine and antimicrobial agents may be useful for procedural sedation or in the ICU. Technological advances such as Bayesian model adjustment based on point-of-care plasma concentration measurements, closed-loop drug delivery and artificial intelligence may improve the ease of use of the anaesthetic drugs and increase the accuracy of titration.

Summary
Newer and more complex modelling techniques and technological advancements can help to deliver anaesthetic drugs, sedatives and other drugs in a more stable and thereby safer way.
Prevalence of Covid-19 Infection and Subsequent Cohorting in a Residential Substance Use Treatment Program in Boston, MA
Authors: Barocas Joshua A. , Blackstone Elizabeth , Bouton Tara C. , Kimmel Simeon D. , Caputo Andrea , Porter Sarah J. , Walley Alexander Y. 
Published: June 2020

Objectives:
The global pandemic of coronavirus disease 2019 (Covid-19) may disproportionately affect persons in congregate settings, including those in residential substance use treatment facilities. To limit the spread of SARS-CoV-2 through congregate settings, universal testing may be necessary. We aimed to determine the point prevalence of SARS-CoV-2 in a residential treatment program setting and to understand the unique challenges of Covid-19 transmission in this setting.

Methods:
We performed a case series of SARS-CoV-2 rT-PCR testing via nasopharyngeal in a residential substance use treatment program for women in Boston. Staff and residents of the treatment program were tested for SARS-CoV-2. The primary outcome was SARS-CoV-2 test result.

Results:
A total of 31 residents and staff were tested. Twenty-seven percent (6/22) of the residents and 44% (4/9) of staff tested positive for SARS-CoV-2. All of the SARS-CoV-2 positive residents resided in the same residential unit. Two positive cases resided together with 2 negative cases in a 4-person room. Two other positive cases resided together in a 2-person room. One positive case resided with 2 negative cases in a 3-person room. One positive case resided with a negative case in a 2-person room. Based on test results, residents were cohorted by infection status and continued to participate in addiction treatment on-site.

Conclusions:
SARS-CoV-2 infection was common among staff and residents within a residential substance use treatment program for women in Boston. Universal SARS-CoV-2 testing in residential substance use programs can be instituted to reduce the risk of further transmission and continue addiction treatment programming when accompanied by adequate space, supplies, and staffing.
Trial of Labor After Two Prior Cesarean Deliveries
Authors: Dombrowski Michael , Illuzzi Jessica L. , Reddy Uma M. , Lipkind Heather S. , Lee Henry C. , Lin Haiqun , Lundsberg Lisbet S. , Xu Xiao 
Published: June 2020

OBJECTIVE:
Trial of labor after cesarean delivery has been mostly studied in the setting of one prior cesarean delivery; controversy remains regarding the risks and benefits of trial of labor for women with two prior cesarean deliveries. This study aimed to examine utilization, success rate, and maternal and neonatal outcomes of trial of labor in this population.

METHODS:
Using linked hospital discharge and birth certificate data, we retrospectively analyzed a cohort of mothers with nonanomalous, term, singleton live births in California between 2010–2012 and had two prior cesarean deliveries and no clear contraindications for trial of labor. We measured whether they attempted labor and, if so, whether they delivered vaginally. Association of patient and hospital characteristics with the likelihood of attempting labor and successful vaginal birth was examined using multivariable regressions. We compared composite severe maternal morbidities and composite severe newborn complications in those who underwent trial of labor as opposed to planned cesarean delivery using a propensity score–matching approach.

RESULTS:
Among 42,771 women who met sample eligibility criteria, 1,228 (2.9%) attempted labor, of whom 484 (39.4%) delivered vaginally. There was no significant difference in the risk of composite severe maternal morbidities, but there was a modest increase in the risk of composite severe newborn complications among women who attempted labor compared with those who did not (2.0% vs 1.4%, P=.04). After accounting for differences in patient and hospital characteristics, propensity score–matched analysis showed no significant association between trial of labor and the risk of composite severe maternal morbidities (odds ratio [OR] 1.16, 95% CI 0.70–1.91), but trial of labor was associated with a higher risk for the composite of severe newborn complications (OR 1.78, 95% CI 1.04–3.04).

CONCLUSION:
Among women with two prior cesarean deliveries, trial of labor was rarely attempted and was successful in 39.4% of attempts. Trial of labor in this population was associated with a modest increase in severe neonatal morbidity.