bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strongly magnetized accretion discs: structure and accretion from global magnetohydrodynamic simulations
Authors: Mishra Bhupendra , Begelman Mitchell C , Armitage Philip J , Simon Jacob B 
Published: December 2019

ABSTRACT
We use global magnetohydrodynamic simulations to study the influence of net vertical magnetic fields on the structure of geometrically thin (H/r ≈ 0.05) accretion discs in the Newtonian limit. We consider initial mid-plane gas to magnetic pressure ratios $\beta _0 = 1000,\, 300$, and 100, spanning the transition between weakly and strongly magnetized accretion regimes. We find that magnetic pressure is important for the discs’ vertical structure in all three cases, with accretion occurring at $z$/R ≈ 0.2 in the two most strongly magnetized models. The disc mid-plane shows outflow rather than accretion. Accretion through the surface layers is driven mainly by stress due to coherent large-scale magnetic field rather than by turbulent stress. Equivalent viscosity parameters measured from our simulations show similar dependencies on initial β0 to those seen in shearing box simulations, though the disc mid-plane is not magnetic pressure dominated even for the strongest magnetic field case. Winds are present but are not the dominant driver of disc evolution. Over the (limited) duration of our simulations, we find evidence that the net flux attains a quasi-steady state at levels that can stably maintain a strongly magnetized disc. We suggest that geometrically thin accretion discs in observed systems may commonly exist in a magnetically ‘elevated’ state, characterized by non-zero but modest vertical magnetic fluxes, with potentially important implications for disc phenomenology in X-ray binaries and active galactic nuclei.
From peculiar morphologies to Hubble-type spirals: the relation between galaxy dynamics and morphology in star-forming galaxies at z ∼ 1.5
Authors: Gillman S , Tiley A L , Swinbank A M , Harrison C M , Smail Ian , Dudzevičiūtė U , Sharples R M , Cortese L , Obreschkow D , Bower R G , Theuns T , Cirasuolo M , Fisher D B , Glazebrook K , Ibar Edo , Mendel J Trevor , Sweet Sarah M 
Published: December 2019

ABSTRACT
We present an analysis of the gas dynamics of star-forming galaxies at z ∼ 1.5 using data from the KMOS Galaxy Evolution Survey. We quantify the morphology of the galaxies using HSTcandels imaging parametrically and non-parametrically. We combine the H α dynamics from KMOS with the high-resolution imaging to derive the relation between stellar mass (M*) and stellar specific angular momentum (j*). We show that high-redshift star-forming galaxies at z ∼ 1.5 follow a power-law trend in specific stellar angular momentum with stellar mass similar to that of local late-type galaxies of the form j*  ∝  M$_*^{0.53\, \pm \, 0.10}$. The highest specific angular momentum galaxies are mostly disc-like, although generally both peculiar morphologies and disc-like systems are found across the sequence of specific angular momentum at a fixed stellar mass. We explore the scatter within the j* – M* plane and its correlation with both the integrated dynamical properties of a galaxy (e.g. velocity dispersion, Toomre Qg, H α star formation rate surface density ΣSFR) and its parametrized rest-frame UV / optical morphology (e.g. Sérsic index, bulge to total ratio, clumpiness, asymmetry, and concentration). We establish that the position in the j* – M* plane is strongly correlated with the star-formation surface density and the clumpiness of the stellar light distribution. Galaxies with peculiar rest-frame UV / optical morphologies have comparable specific angular momentum to disc- dominated galaxies of the same stellar mass, but are clumpier and have higher star formation rate surface densities. We propose that the peculiar morphologies in high-redshift systems are driven by higher star formation rate surface densities and higher gas fractions leading to a more clumpy interstellar medium.
Case AD, AR, and AS binary evolution and their possible connections with W UMa binaries
Authors: Jiang Dengkai 
Published: December 2019

ABSTRACT
Close detached binaries were theoretically predicted to evolve into contact by three subtypes of case A binary evolution, cases AD, AR, and AS, which correspond to the formation of contact during dynamic-, thermal-, and nuclear-time-scale mass transfer phases, respectively. It is unclear, however, what is the difference between contact binaries in these subtypes, and whether all of these subtypes can account for the formation of observed W Ursae Majoris (W UMa) binaries. Using Eggleton’s stellar evolution code with the non-conservative assumption, I obtained the low-mass contact binaries produced by cases AD, AR, and AS at the moment of contact and their parameter spaces. The results support that the progenitors of low-mass contact binaries are detached binaries with orbital periods shorter than $\sim 2\!-\!5\,$ d, and their borderlines depend strongly on the primary mass. In addition, the period–colour relations for cases AR and AS can be in better agreement with that for observed W UMa candidates, but case AD shows a significantly worse agreement. Moreover, cases AR and AS can produce a short-period limit (corresponding to a low-mass limit) at almost any age, e.g. from young age ($\sim 0.2\,$ Gyr) to old age ($\sim 13\,$ Gyr), agreeing with observed W UMa binaries in star clusters, but no such limit occurs for case AD at any age. These results support that cases AR and AS, as opposed to case AD, can lead to W UMa binaries (including young W UMa binaries).
Physical properties of the CDFS X-ray sources through fitting spectral energy distributions
Authors: Guo Xiaotong , Gu Qiusheng , Ding Nan , Contini E , Chen Yongyun 
Published: December 2019

ABSTRACT
The physical parameters of galaxies and/or active galactic nucleus (AGNs) can be derived by fitting their multiband spectral energy distributions (SEDs). By using cigale code, we perform multiband SED fitting (from ultraviolet to infrared) for 791 X-ray sources (518 AGNs and 273 normal galaxies) in the 7 Ms Chandra Deep Field-south survey (CDFS). We consider the contributions from AGNs and adopt more accurate redshifts than published before. Therefore, more accurate star formation rates (SFRs) and stellar masses (M*) are derived. We classify the 518 AGNs into type-I and type-II based on their optical spectra and their SEDs. Moreover, six AGN candidates are selected from the 273 normal galaxies based on their SEDs. Our main results are as follows: (1) the host galaxies of AGNs have larger M* than normal galaxies, implying that AGNs prefer to host in massive galaxies; (2) the specific star formation rates (sSFRs) of AGN host galaxies are different from those of normal galaxies, suggesting that AGN feedback may play an important role in the star formation activity; (3) we find that the fraction of optically obscured AGNs in CDFS decreases with the increase of intrinsic X-ray luminosity, which is consistent with previous studies; and (4) the host galaxies of type-I AGNs tend to have lower M* than type-II AGNs, which may suggest that dust in the host galaxy may also contribute to the optical obscuration of AGNs.
Variations of interplanetary magnetic field on various long time-scales
Authors: Nagovitsyn Yury A , Osipova Aleksandra A 
Published: December 2019

ABSTRACT
The IDV index of geomagnetic activity is used by many researchers as a proxy of the interplanetary magnetic field (IMF) strength B. Using the original multiscale regression (MSR) method based on wavelet transformation, we obtained a long series of B values starting from 1845. Then, based on the new 2.0 versions of the sunspot number and group sunspot number and using MSR method and this series as a reference, we reconstructed IMF strength B starting from 1610. Further extension of the reconstruction is associated with radiocarbon reconstructions of solar activity at a time-scale of up to several millennia. It is shown that in the last 3200 yr the IMF strength has been experiencing a downward trend of −(0.39 ± 0.17) · 10−3 nT· yr−1.
Enzyme Evolution: An Epistatic Ratchet versus a Smooth Reversible Transition
Authors: Ben-David Moshe , Soskine Misha , Dubovetskyi Artem , Cherukuri Kesava-Phaneendra , Dym Orly , Sussman Joel L , Liao Qinghua , Szeler Klaudia , Kamerlin Shina Caroline Lynn , Tawfik Dan S 
Published: December 2019

Abstract
Evolutionary trajectories are deemed largely irreversible. In a newly diverged protein, reversion of mutations that led to the functional switch typically results in loss of both the new and the ancestral functions. Nonetheless, evolutionary transitions where reversions are viable have also been described. The structural and mechanistic causes of reversion compatibility versus incompatibility therefore remain unclear. We examined two laboratory evolution trajectories of mammalian paraoxonase-1, a lactonase with promiscuous organophosphate hydrolase (OPH) activity. Both trajectories began with the same active-site mutant, His115Trp, which lost the native lactonase activity and acquired higher OPH activity. A neo-functionalization trajectory amplified the promiscuous OPH activity, whereas the re-functionalization trajectory restored the native activity, thus generating a new lactonase that lacks His115. The His115 revertants of these trajectories indicated opposite trends. Revertants of the neo-functionalization trajectory lost both the evolved OPH and the original lactonase activity. Revertants of the trajectory that restored the original lactonase function were, however, fully active. Crystal structures and molecular simulations show that in the newly diverged OPH, the reverted His115 and other catalytic residues are displaced, thus causing loss of both the original and the new activity. In contrast, in the re-functionalization trajectory, reversion compatibility of the original lactonase activity derives from mechanistic versatility whereby multiple residues can fulfill the same task. This versatility enables unique sequence-reversible compositions that are inaccessible when the active site was repurposed toward a new function.
Adjacent mutations in the archaeal Rad50 ABC ATPase D-loop disrupt allosteric regulation of ATP hydrolysis through different mechanisms
Authors: Boswell Zachary K , Canny Marella D , Buschmann Tanner A , Sang Julie , Latham Michael P 
Published: December 2019

Abstract
DNA damage is the driving force for mutation and genomic instability, which can both lead to cell death or carcinogenesis. DNA double strand breaks are detected and processed in part by the Mre11–Rad50–Nbs1 protein complex. Although the Mre11–Rad50–Nbs1 complex is essential, several spontaneous mutations have been noted in various cancers. One of these mutations, within a conserved motif of Rad50, resulted in an outlier curative response in a clinical trial. We show through biochemical and biophysical characterization that this cancer-associated mutation and a second mutation to the adjacent residue, previously described in a breast cancer patient, both have gain-of-function Rad50 ATP hydrolysis activity that results not from faster association of the ATP-bound form but faster dissociation leading to less stable Rad50 dimer. This disruption impairs the regulatory functions of the protein complex leading to a loss of exonuclease activity from Mre11. Interestingly, these two mutations affect Rad50 structure and dynamics quite differently. These studies describe the relationship between function, structure, and molecular motions in improperly regulated Rad50, which reveal the underlying biophysical mechanism for how these two cancer-associated mutations affect the cell.
Does Choice Really Imply Excluded Middle? Part I: Regimentation of the Goodman–Myhill Result, and Its Immediate Reception†
Authors: Tennant Neil 
Published: December 2019

ABSTRACTThe one-page 1978 informal proof of Goodman and Myhill is regimented in a weak constructive set theory in free logic. The decidability of identities in general ($a\!=\!b\vee\neg a\!=\!b$) is derived; then, of sentences in general ($\psi\vee\neg\psi$). Martin-Löf’s and Bell’s receptions of the latter result are discussed. Regimentation reveals the form of Choice used in deriving Excluded Middle. It also reveals an abstraction principle that the proof employs. It will be argued that the Goodman–Myhill result does not provide the constructive set theorist with a dispositive reason for not adopting (full) Choice.
Update of a Study of Not Ceasing Anticoagulants for Patients Undergoing Injection Procedures for Spinal Pain
Authors: Endres Stephen , Hefti Karlee , Schlimgen Erika , Bogduk Nikolai 
Published: December 2019

Abstract

Objectives
To determine prevalence rates of hemorrhagic complications in patients who either ceased or continued anticoagulants during interventional pain procedures.

Methods
A total of 1,936 consecutive patients were prospectively monitored during a total of 12,723 injection procedures. The prevalence of hemorrhagic complications was tallied for a variety of procedures performed on patients who ceased or continued various anticoagulants.

Results
No hemorrhagic complications occurred in any patient who continued anticoagulants. Sufficiently large sample sizes were obtained to conclude that, in patients who continued warfarin or clopidrogel during lumbar transforaminal injections and for lumbar facet procedures, the zero prevalence of complications had 95% confidence intervals of 0% to 0.3%. This prevalence was significantly lower than the risk of medical complications in patients who ceased warfarin.

Conclusions
Lumbar transforaminal injections and lumbar facet injections have a very low rate of hemorrhagic complications when patients continue to take anticoagulants.
Race and Economic Opportunity in the United States: an Intergenerational Perspective*
Authors: Chetty Raj , Hendren Nathaniel , Jones Maggie R , Porter Sonya R 
Published: December 2019

AbstractWe study the sources of racial disparities in income using anonymized longitudinal data covering nearly the entire U.S. population from 1989 to 2015. We document three results. First, black Americans and American Indians have much lower rates of upward mobility and higher rates of downward mobility than whites, leading to persistent disparities across generations. Conditional on parent income, the black-white income gap is driven by differences in wages and employment rates between black and white men; there are no such differences between black and white women. Hispanic Americans have rates of intergenerational mobility more similar to whites than blacks, leading the Hispanic-white income gap to shrink across generations. Second, differences in parental marital status, education, and wealth explain little of the black-white income gap conditional on parent income. Third, the black-white gap persists even among boys who grow up in the same neighborhood. Controlling for parental income, black boys have lower incomes in adulthood than white boys in 99% of Census tracts. The few areas with small black-white gaps tend to be low-poverty neighborhoods with low levels of racial bias among whites and high rates of father presence among blacks. Black males who move to such neighborhoods earlier in childhood have significantly better outcomes. However, less than 5% of black children grow up in such areas. Our findings suggest that reducing the black-white income gap will require efforts whose impacts cross neighborhood and class lines and increase upward mobility specifically for black men.
Ambiguous Policy Announcements
Authors: Michelacci Claudio , Paciello Luigi 
Published: December 2019

AbstractWe study the effects of monetary announcements when agents face Knightian uncertainty about the commitment capacity of the monetary authority. Households are ambiguity averse and differentially exposed to inflation due to differences in wealth. In response to the announcement of a future monetary loosening, only wealthy households (creditors) act as if the announcement will be fully implemented, due to the potential wealth losses from future inflation. As a result the economy responds as if aggregate net wealth falls, which attenuates the effects of the announcement. Redistributing from super-wealthy to middle-wealthy households makes the announcement more expansionary, in the extreme as expansionary as under a fully credible announcement.
A 5-Year Retrospective Review of the Health Supervision Received by Children with Down Syndrome at a South African Regional Hospital
Authors: Schoonraad Leilah , Slogrove Amy , Engelbrecht Arnold , Urban Michael F 
Published: December 2019

Abstract

Introduction
In 2011, the American Academy of Paediatrics (AAP) published revised health supervision guidelines for children with Down syndrome (DS). In the absence of South African guidelines, we described the health supervision received by children with DS at a rural regional hospital in the Western Cape, South Africa compared with the AAP guidelines.

Methods
This was a 5-year retrospective description of the implementation of the 2011 AAP guidelines at the DS clinic at Worcester Provincial Hospital (WPH), specifically related to screening for and management of cardiac, thyroid, hearing and haematological disorders.

Results
Sixty-two children received care at WPH DS clinic during the study period. Thirty-six (58%) children lived in Worcester while 26 (42%) children were referred from peripheral hospitals. The median age at first clinic visit was 0.5 years [inter-quartile range (IQR) 0.2–1.2], a total of 177 person-years of follow-up with a median duration of 1.8 years (IQR 0.3–4.8). Two deaths occurred during the study period. Forty-nine (79%) children had a screening echocardiogram performed, the median age at first echocardiogram was 0.8 years (IQR 0.2–1.4). Five (14%) children from WPH compared with no children from the peripheral hospitals received the echocardiogram within the first month of life in keeping with AAP guidance (p = 0.06). Those requiring cardiac surgery were operated on at a median age of 2 years (IQR 0.9–2.3). Compared with the AAP guidelines, within the first month of life 17 (27%) children had a thyroid screen, 20 (32%) children had a full blood count and 7 (11%) children had a hearing assessment.

Conclusion
AAP guidelines for health supervision in DS are challenging to achieve within our local health system. The development and advocacy for a South African DS health supervision guideline that can be applied not only in specialist clinics might improve the care of children with DS.
Physical Performance Following Hematopoietic Stem Cell Transplantation: A Prospective Observational Study
Authors: Rindflesch Aaron B. , Hake Melissa P. , Spiten Megan A. , Trueblood Jinise K. , Reiplinger Allison F. , Dykstra Rebecca L. , Hollman John H. 
Published: December 2019

Background and Purpose/Objective:
Patients undergoing hematopoietic stem cell transplantation (HSCT) are at risk for strength impairments and activity limitations. Research describing how HSCT affects physical performance is limited. The purposes of this study were to report the short-term (≤30 days) effects of HSCT on physical performance and to compare changes among patients during the engraftment and recovery periods following HSCT.

Methods: Design:
Prospective observational study.

Setting:
Academic medical center.

Patients:
Twenty-five adults 21 years and older undergoing HSCT.

Intervention:
None.

Measurements:
Measures were collected at 3 time points: (1) day of transplant; (2) 8 to 14 days posttransplant; and (3) 15 to 30 days posttransplant. Beside demographic data, the authors collected Short Physical Performance Battery (SPPB) scores, Functional Comorbidity Index scores, resting heart rate, and hospitalization status. Longitudinal changes in SPPB scores were analyzed with a generalized linear model (α = 0.05).

Results:
SPPB scores were negatively associated with patients' body mass index values and resting heart rate measurements. Additionally, the hospitalization × time interaction was statistically significant. SPPB scores among nonhospitalized patients remained consistent across the testing periods but among hospitalized patients decreased from the day of transplant to both the 8 to 14 days (mean change = 4.0 points) and 15 to 30 days (mean change = 4.1 points) posttransplant time points.

Conclusion:
Physical performance scores decreased in the first 30 days of recovery among patients who were hospitalized following HSCT, but not among patients who received transplant on an outpatient basis. Future studies to examine causes of and interventions for the reduction in physical performance among hospitalized patients post-HSCT are warranted.
Nordic Pole Walking for Individuals With Cancer: A Feasibility Randomized Controlled Trial Assessing Physical Function and Health-Related Quality of Life
Authors: Cunningham Elise , Weaver Robert R. , Lemonde Manon , Dogra Shilpa , Nonoyama Mika L. 
Published: December 2019

Background:
Individuals with a diagnosis of cancer tend to be inactive and have symptoms that impact quality of life. An individualized, community-based Nordic pole walking (NPW) program may help.

Methods:

Primary Objective: To assess feasibility using the Thabane framework of a randomized controlled trial (RCT). Secondary Objective: To determine the effects of NPW on physical function (Six-Minute Walk Test [6MWT], 30-second [30-s] chair stand test, Unsupported Upper-Limb Exercise Test, handgrip strength, physical activity [PA]), and health-related quality of life (HRQOL, 36-item Short-Form Health Survey [SF-36]). The Study Design: An 8-week multicentered block RCT (no blinding) comparing a community-based NPW program (vs usual daily routine) for adults with non-small cell lung, prostate, colorectal, and endometrial cancer.

Results:
Eight individuals were enrolled in the study with n = 4 per group (1 dropout in the NPW arm; = 67 ± 6 years). The study was deemed “feasible with modifications.” NPW significantly improved (statistically and clinically) the 30-s chair stand test when compared with baseline. There was improved 6MWT, PA levels, and SF-36 when compared with the control group (not statistically significant). No adverse events occurred.

Discussion, Limitations, and Conclusions:
NPW was feasible for individuals with cancer and may improve physical function, PA, and HRQOL. Larger samples are required to determine efficacy and/or program effectiveness. Future programs should include collaboration with hospital cancer centers and support groups, promotion of participant and community engagement with NPW, and consideration of the population's unique characteristics. NPW programs should include individualized exercise prescriptions, behavior change techniques, social aspects, HRQOL assessments, and device-measured PA.
Progresses in the imaging of calcium pyrophosphate crystal disease
Authors: Andrés Mariano , Sivera Francisca , Pascual Eliseo 
Published: December 2019

Purpose of review
Calcium pyrophosphate crystal disease (CPPD) may be considered a neglected disorder, common in clinics and wards, but not receiving enough attention since the time it was recognized as a disease entity. This review aims to highlight the advances occurred in recent years in terms of imaging of CPPD, and their potential aid in diagnosing CPPD.

Recent findings
The main advances in CPPD imaging have occurred with ultrasound and computed tomography. Ultrasound has been shown as more sensitive than conventional radiography in detecting chondrocalcinosis. OMERACT definitions of ultrasound signs of CPPD have been provided; validations process is still ongoing. Computed tomography has been used to assess CPPD at the spine. Some studies suggest that dual-energy scans could accurately detect chondrocalcinosis and discriminate from other calcified structures.

Summary
Ultrasound and computed tomography may have a role in CPPD detection, though the specifics are still unclear. It remains necessary to have studies comparing them with synovial fluid analysis for crystals in a clinical scenario.