bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phase and amplitude asymmetry in the quasi-biennial oscillation of solar Hα flare activity
Authors: Deng L H , Zhang X J , Li G Y , Deng H , Wang F 
Published: June 2019

ABSTRACT
Quasi-biennial oscillation (QBO) of solar magnetic activities is intrinsic to dynamo mechanism, but still far from fully understood. In this work, the phase and amplitude asymmetry of solar QBO of Hα flare activity in the northern and southern hemispheres is studied by the ensemble empirical mode decomposition, the cross-correlation analysis, and the wavelet transform technique. The following results are found: (1) solar QBO of Hα flare index in the two hemispheres has a complicated phase relationship, but does not show any systematic regularity; and (2) the solar cycle mode of solar Hα flare index in the northern hemisphere generally leads that in the southern one by nine months for the time interval from 1966 to 2014. The possible origin of these results is discussed.
Study of the reflection spectrum of the bright atoll source GX 3 + 1 with NuSTAR
Authors: Mondal Aditya S , Dewangan G C , Raychaudhuri B 
Published: June 2019

ABSTRACT
We report on the NuSTAR observation of the atoll type neutron star (NS) low-mass X-ray binary GX 3 + 1 performed on 2017 October 17. The source was found in a soft X-ray spectral state with 3–70 keV luminosity of LX ∼ 3 × 1037 erg s−1 (${\sim } 16{{\ \rm per\ cent}}$ of the Eddington luminosity), assuming a distance of 6 kpc. A positive correlation between intensity and hardness ratio suggests that the source was in the banana branch during this observation. The broad-band 3–70 keV NuSTAR spectral data can be described by a two-component continuum model consisting of a disc blackbody (kTdisc ∼ 1.8 keV) and a single temperature blackbody model (kTbb ∼ 2.7 keV). The spectrum shows a clear and robust indication of relativistic reflection from the inner disc which is modelled with a self-consistent relativistic reflection model. The accretion disc is viewed at an inclination of i ≃ 22°–26° and extended close to the NS, down to $R_\text{in}=(1.2\!-\!1.8) R_\text{ISCO}\:(\simeq 6.1\!-\!9.1\, R_{\mathrm{ g}}\: \text{or}\: 14\!-\!20.5$ km) which allows an upper limit on the NS radius (≤13.5 km). Based on the measured flux and the mass accretion rate, the maximum radial extension for the boundary layer is estimated to be ∼6.3 Rg from the NS surface. However, if the disc is not truncated by the boundary layer but by the magnetosphere, an estimated upper limit on the polar magnetic field would be of B ≤ 6 × 108 G.
Early-type galaxies in low-density environments: NGC 6876 explored through its globular cluster system
Authors: Ennis Ana I , Bassino Lilia P , Caso Juan P , De Bórtoli Bruno J 
Published: June 2019

ABSTRACT
We present the results of a photometric study of the early-type galaxy NGC 6876 and the surrounding globular cluster (GC) system. The host galaxy is a massive elliptical, the brightest of this type in the Pavo Group. According to its intrinsic brightness (Mv ∼ −22.7), it is expected to belong to a galaxy cluster instead of a poor group. Observational material consists of g′, r′, i′ images obtained with the Gemini/GMOS camera. The selected GC candidates present a clear bimodal colour distribution at different galactocentric radii, with mean colours and dispersions for the metal-poor (‘blue’) and metal-rich (‘red’) typical of old GCs. The red subpopulation dominates close to the galaxy centre, in addition to the radial projected distribution showing that they are more concentrated towards the galaxy centre. The azimuthal projected distribution shows an overdensity in the red subpopulation in the direction of a trail observed in X-ray that could be evidence of interactions with its spiral neighbour NGC 6872. The turnover of the luminosity function gives an estimated distance modulus (m − M) ≈ 33.5 and the total population amounts to 9400 GCs, i.e. a quite populous system. The halo mass obtained using the number ratio (i.e. the number of GCs with respect to the baryonic and dark mass) gives a total of ∼1013, meaning it is a very massive galaxy, given the environment.
PRIME: PSF Reconstruction and Identification for Multiple-source characterization Enhancement – application to Keck NIRC2 imager
Authors: Beltramo-Martin O , Correia C M , Ragland S , Jolissaint L , Neichel B , Fusco T , Wizinowich P L 
Published: June 2019

ABSTRACTIn order to enhance the scientific exploitation of adaptive optics (AO)-assisted observations, we investigate a novel hybrid concept to improve the parametric estimation of point spread function (PSF) called PSF Reconstruction and Identification for Multiple-source characterization Enhancement (PRIME). PRIME uses both focal and pupil-plane measurements to estimate jointly the model parameters related to the atmosphere [$C_n^2(h)$, seeing] and the AO system (e.g. optical gains and residual low-order errors). Photometry and astrometry are provided as by-products. The parametric model in use is flexible enough to be scaled with field location and wavelength, making it a proper choice for optimized on-axis and off-axis data-reduction across the spectrum. Here, we present the methodology and validate PRIME on engineering and binary Keck II telescope NIRC2 images. We also present applications of PSF model parameters retrieval using PRIME: (i) calibrate the PSF model for observations void of stars on the acquired images, i.e. optimize the PSF reconstruction process, (ii) update the AO error breakdown mutually constrained by the telemetry and the images in order to speculate on the origin of the missing error terms and evaluate their magnitude, and (iii) measure photometry and astrometry with an application to the triple system Gl569 images.
Effects of the albedo and disc on the zero velocity curves and linear stability of equilibrium points in the generalized restricted three-body problem
Authors: Yousuf Saleem , Kishor Ram 
Published: June 2019

ABSTRACT
The important aspects of a dynamical system are its stability and the factors that affect its stability. In this paper, we present an analysis of the effects of the albedo and the disc on the zero velocity curves, the existence of equilibrium points and their linear stability in a generalized restricted three-body problem (RTBP). The proposed problem consists of the motion of an infinitesimal mass under the gravitational field of a radiating-oblate primary, an oblate secondary and a disc that is rotating about the common centre of mass of the system. Significant effects of the albedo and the disc are observed on the zero velocity curves, on the positions of equilibrium points and on the stability region. A linear stability analysis of collinear equilibrium points L1, 2, 3 is performed with respect to the mass parameter μ and albedo parameter QA of the secondary, separately. It is found that L1, 2, 3 are unstable in both cases. However, the non-collinear equilibrium points L4, 5 are stable in a finite range of mass ratio μ. After analysing the individual as well as combined effects of the radiation pressure force of the primary, the albedo force of the secondary, the oblateness of both the primary and secondary and the disc, it is found that these perturbations play a significant role in the design of the trajectories in the vicinity of equilibrium points and in the analysis of their stability property. In the future, the results obtained will improve existing results and will help in the analysis of different space missions. These results are limited to the regular symmetric disc and radiation pressure, which can be extended later.
Spectroscopy with the Engineering Development Array: cold H+ at 63 MHz towards the Galactic Centre
Authors: Oonk J B R , Alexander E L , Broderick J W , Sokolowski M , Wayth R 
Published: June 2019

Abstract
The Engineering Development Array (EDA) is a single test station for Square Kilometre Array (SKA) precursor technology. We have used the EDA to detect low-frequency radio recombination lines (RRLs) from the Galactic Centre region. Low-frequency RRLs are an area of interest for future low-frequency SKA work as these lines provide important information on the physical properties of the cold neutral medium. In this project, we investigate the EDA, its bandpass, and the radio frequency interference environment for low-frequency spectroscopy. We present line spectra from 30 to 325 MHz for the Galactic Centre region. The decrease in sensitivity for the EDA at the low end of the receiver prevents carbon and hydrogen RRLs to be detected below 40 and 60 MHz, respectively. RFI strongly affects frequencies in the range 276–292, 234–270, 131–138, 95–102, and below 33 MHz. Cnα RRLs were detected in absorption for quantum levels n = 378–550 (39–121 MHz) and in emission for n = 272–306 (228–325 MHz). Cnβ lines were detected in absorption for n = 387–696 (39–225 MHz). Hnα RRLs were detected in emission for n = 272–480 (59–325 MHz). Hnβ lines were detected for n = 387–453 (141–225 MHz). The stacked Hnα detection at 63 MHz is the lowest frequency detection made for hydrogen RRLs and shows that a cold (partially) ionized medium exists along the line of sight to the Galactic Centre region. The size and velocity of this cold H+ gas indicates that it is likely associated with the nearby Riegel–Crutcher cloud.
Association of Overlapping Neurosurgery With Patient Outcomes at a Large Academic Medical Center
Authors: Agarwal Prateek , Ramayya Ashwin G , Osiemo Benjamin , Goodrich Stephen , Glauser Gregory , McClintock Scott D , Chen H Isaac , Schuster James M , Grady M Sean , Malhotra Neil R 
Published: June 2019

Abstract

BACKGROUND
Limited data exist on the safety of overlapping surgery, a practice that has recently received widespread attention.

OBJECTIVE
To examine the association of overlapping neurosurgery with patient outcomes.

METHODS
A total of 3038 routinely scheduled, elective neurosurgical procedures were retrospectively reviewed at a single, multihospital academic medical center. Procedures were categorized into any overlap or no overlap and further subcategorized into beginning overlap (first 50% of procedure only), end overlap (last 50% of procedure only), and middle overlap (overlap at the midpoint).

RESULTS
A total of 1030 (33.9%) procedures had any overlap, whereas 278 (9.2%) had beginning overlap, 190 (6.3%) had end overlap, and 476 (15.7%) had middle overlap. Compared with no overlap patients, patients with any overlap had lower American Society of Anesthesiologists scores (P = .0018), less prior surgery (P < .0001), and less prior neurosurgery (P < .0001), though they tended to be older (P < .0001) and more likely in-patients (P = .0038). Any-overlap patients had decreased overall mortality (2.8% vs 4.5%; P = .025), 30- to 90-d readmission rate (3.1% vs 5.5%; P = .0034), 30- to 90-d reoperation rate (1.0% vs 2.0%; P = .03), 30- to 90-d emergency room (ER) visit rate (2.1% vs 3.7%; P = .018), and future surgery on index admission (2.8% vs 7.3%; P < .0001). Multiple regression analysis validated noninferior outcomes for overlapping surgery, except for the association of increased future surgery on index admission with middle overlap (odds ratio 3.99; 95% confidence interval [1.91, 8.33]).

CONCLUSION
Overlapping neurosurgery is associated with noninferior patient outcomes that may be driven by surgeon selection of healthier patients, regardless of specific overlap timing.
Congress of Neurological Surgeons Systematic Review and Evidence-Based Guideline on the Incidence of Shunt-Dependent Hydrocephalus in Infants With Myelomeningocele After Prenatal Versus Postnatal Repair
Authors: Tamber Mandeep S , Flannery Ann Marie , McClung-Smith Catherine , Assassi Nadege , Bauer David F , Beier Alexandra D , Blount Jeffrey P , Durham Susan R , Klimo Jr Paul , Nikas Dimitrios C , Rehring Patricia , Tyagi Rachana , Mazzola Catherine A 
Published: June 2019

Abstract

BACKGROUND
Myelomeningocele (MM) is a condition that is responsible for considerable morbidity in the pediatric population. A significant proportion of the morbidity related to MM is attributable to hydrocephalus and the surgical management thereof. Postnatal repair remains the most common form of treatment; however, increased rates of prenatal diagnosis, advances in fetal surgery, and a hypothesis that neural injury continues in utero until the MM defect is repaired have led to the development and evaluation of prenatal surgery as a means to improve outcomes in afflicted infants.

OBJECTIVE
The objective of this guideline is to systematically evaluate the literature to determine whether there is a difference in the proportion of patients who develop shunt-dependent hydrocephalus in infants who underwent prenatal MM repair compared to infants who had postnatal repair.

METHODS
The Guidelines Task Force developed search terms and strategies used to search PubMed and Embase for relevant literature published between 1966 and September 2016. Strict inclusion/exclusion criteria were used to screen abstracts and to develop a list of relevant articles for full-text review. Full-text articles were then reviewed, and when appropriate, included as evidence.

RESULTS
A total of 87 abstracts were identified and reviewed by 3 independent reviewers. Thirty-nine full-text articles were selected for analysis. Three studies met selection criteria and were included in the evidence table.

CONCLUSION
Class I evidence from 1 study and class III evidence from 2 studies suggest that, in comparison to postnatal repair, prenatal surgery for MM reduces the risk of developing shunt-dependent hydrocephalus. Therefore, prenatal repair of MM is recommended for those fetuses who meet specific criteria for prenatal surgery to reduce the risk of developing shunt-dependent hydrocephalus (level I). Differences between prenatal and postnatal repair with respect to the requirement for permanent cerebrospinal fluid diversion should be considered alongside other relevant maternal and fetal factors when deciding upon a preferred method of MM closure.
The full guideline can be found at https://www.cns.org/guidelines/guidelines-spina-bifida-chapter-2.
Routine Immediate Eye Examination at the Point of Care for Diagnosis of AIDS-Related Cytomegalovirus Retinitis Among Patients With a CD4 Count &lt;100 in Myanmar
Authors: Ei Win Le Shwe Sin , Pyar Soe Kyi , Hilbig Adelene , Murray Jillian , Heiden David 
Published: June 2019

Abstract
A retrospective review of diagnosis of cytomegalovirus retinitis (CMVR) before and after introduction of routine immediate eye examination among AIDS patients in Myanmar with an absolute CD4 T-cell count &lt;100 cells/μL demonstrated an increased detection of CMVR from 1.1% (14/1233) to 10.7% (65/608), an improvement of ~10-fold. Diagnosis of CMVR was achieved a mean of 2 days after clinic enrollment.
Structured Cognitive Training Yields Best Results in Healthy Older Adults, and Their ApoE4 State and Baseline Cognitive Level Predict Training Benefits
Authors: Roheger Mandy , Kessler Josef , Kalbe Elke 
Published: June 2019

Background:
Cognitive training has been shown to improve cognitive functions in healthy older adults. However, little is known about which specific variables are responsible for the improvement.

Objective:
Our aim was to evaluate whether healthy older adults benefit more from a structured cognitive training program than an unstructured brain jogging program and to identify possible predictors for training success, including apolipoprotein E4 (apoE4).

Methods:
In a randomized controlled trial, participants completed either a 6-week structured cognitive training program (n=35) or a 6-week unstructured brain jogging program (n=35). A control group received no training and was not part of the randomization procedure (n=35). Overall, 105 participants were included in the training data analyses, focusing on verbal memory, attention, and executive functions. Data from an additional 45 previously trained, healthy older adults were used for the predictor analysis.

Results:
A significant Time×Training interaction in favor of the structured cognitive training program was found in verbal memory. Low baseline performance on neuropsychological tests was a significant predictor for benefits in verbal memory, attention, and executive functions. A subgroup analysis (n=35) revealed that only noncarriers of the apoE4 allele showed significant gains in long-term verbal memory and attention.

Conclusions:
Our results support the greater effectiveness of structured cognitive training on verbal memory compared with brain jogging and no training. The success of this type of training program may be predicted by sociodemographic, cognitive, and genetic variables.
GenEditID: an open-access platform for the high-throughput identification of CRISPR edited cell clones
Authors: Xue Ying , Tung YC Loraine , Siersbaek Rasmus , Pajon Anne , Chilamakuri Chandra SR , Alvarez-Fernandez Ruben , Bowers Richard , Carroll Jason , Eldridge Matthew , Russell Alasdair , Merkle Florian T. 
Published: June 2019

ABSTRACTCRISPR-Cas9-based gene editing is a powerful tool to reveal genotype-phenotype relationships, but identifying cell clones carrying desired edits remains challenging. To address this issue we developed GenEditID, a flexible, open-access platform for sample tracking, analysis and integration of multiplexed deep sequencing and proteomic data, and intuitive plate-based data visualisation to facilitategeneedited cloneidentification. To demonstrate the scalability and sensitivity of this method, we identified KO clones in parallel from multiplexed targeting experiments, and optimised conditions for single base editing using homology directed repair. GenEditID enables non-specialist groups to expand their gene targeting efforts, facilitating the study of genetically complex human disease.
Protein structure from experimental evolution
Authors: Stiffler Michael A , Poelwijk Frank J , Brock Kelly , Stein Richard R , Teyra Joan , Sidhu Sachdev , Marks Debora S , Gauthier Nicholas P , Sander Chris 
Published: June 2019

AbstractNatural evolution encodes rich information about the structure and function of biomolecules in the genetic record. Previously, statistical analysis of co-variation patterns in natural protein families has enabled the accurate computation of 3D structures. Here, we explored whether similar information can be generated by laboratory evolution, starting from a single gene and performing multiple cycles of mutagenesis and functional selection. We evolved two bacterial antibiotic resistance proteins, β-lactamase PSE1 and acetyltransferase AAC6, and obtained hundreds of thousands of diverse functional sequences. Using evolutionary coupling analysis, we inferred residue interactions in good agreement with contacts in the crystal structures, confirming genetic encoding of structural constraints in the selected sequences. Computational protein folding with contact constraints yielded 3D structures with the same fold as that of natural relatives. Evolution experiments combined with inference of residue interactions from sequence information opens the door to a new experimental method for the determination of protein structures.
Multifactorial motor behavior assessment for real-time evaluation of emerging therapeutics to treat neurologic impairments
Authors: Islam Riazul , Cuellar Carlos , Felmlee Ben , Riccelli Tori , Silvernail Jodi , Boschen Suelen Lucio , Grahn Peter , Lavrov Igor 
Published: June 2019

AbstractIntegrating multiple assessment parameters of motor behavior is critical for understanding neural activity dynamics during motor control in both intact and dysfunctional nervous systems. Here, we described a novel approach (termed Multifactorial Behavioral Assessment (MfBA)) to integrate, in real-time, electrophysiological and biomechanical properties of rodent spinal sensorimotor network activity with behavioral aspects of motor task performance. Specifically, the MfBA simultaneously records limb kinematics, multi-directional forces and electrophysiological metrics, such as high-fidelity chronic intramuscular electromyography synchronized in time to spinal stimulation in order to characterize spinal cord functional motor evoked potentials (fMEPs). Additionally, we designed the MfBA to incorporate a body weight support system to allow bipedal and quadrupedal stepping on a treadmill and in an open field environment to assess function in rodent models of neurologic disorders that impact motor activity This novel approach was validated using, a neurologically intact cohort, a cohort with unilateral Parkinsonian motor deficits due to midbrain lesioning, and a cohort with complete hind limb paralysis due to T8 spinal cord transection. In the SCI cohort, lumbosacral epidural electrical stimulation (EES) was applied, with and without administration of the serotonergic agonist Quipazine, to enable hind limb motor functions following paralysis. The results presented herein demonstrate the MfBA is capable of integrating multiple metrics of motor activity in order to characterize relationships between EES inputs that modulate mono- and polysynaptic outputs from spinal circuitry which in turn, can be used to elucidate underlying electrophysiologic mechanisms of motor behavior by synchronizing these datasets to metrics of movement and behavior. These results also demonstrate that proposed MfBA is an effective tool to integrate biomechanical and electrophysiology metrics, synchronized to therapeutic inputs such as EES or pharmacology, during body weight supported treadmill or open field motor activities, to target a high range of variations in motor behavior as a result of neurological deficit at the different levels of CNS.
The Protein Mat(ters) - Revealing Biologically Relevant Mechanical Contribution of Collagen and Fibronectin Coated Micropatterns
Authors: Horvath Aron N. , Holenstein Claude N. , Silvan Unai , Snedeker Jess G. 
Published: June 2019

AbstractUnderstanding cell-material interactions requires accurate characterization of substrate mechanics, which are generally measured by indentation-type atomic force microscopy. Although model extracellular matrix coatings are used to facilitate cell-substrate adhesion, their tensile mechanical properties are generally unknown. In this study a novel tensile mechanical characterization of collagen and fibronectin micropatterned polyacrylamide hydrogels is performed. Our findings reveal that the protein coating itself has measurable and biologically relevant consequences, with ligand-specific tensile resistance of the patterned regions relative to the non-patterned surfaces. To our knowledge our study is the first to uncover a direction-dependent mechanical behavior of the protein coatings and to demonstrate that it affects cellular response relative to substrate mechanics.