Local Disk Research Articles

Multicentre interlaboratory analysis of routine susceptibility testing with a challenge panel of resistant strains

In order to elaborate a new national challenge panel of resistant Gram-negative bacilli and Gram-positive cocci strains for the validation of routine antimicrobial susceptibility testing (AST) methods, an interlaboratory evaluation was organised. The results of 12 well-characterised multidrug-resistant strains tested by nine laboratories using local disk diffusion (DD) and automated AST (AUST) methods were compared with the reference broth microdilution method. Overall categorical agreement ranged from 70% to 100% both for DD and AUST and was >90% for all but one strain for all antibiotics. Our multicentre AST study showed good reproducibility and the panel can be used as national resistant reference strains for routine AST validation.

Stars in the local galactic thick disc and halo in Gaia EDR3: a catalogue of half a million local main-sequence stars with photometric metallicities

ABSTRACT We present a catalogue of 551 214 main-sequence stars in the local (d < 2 kpc) Galactic thick disc and halo, based on a search of stars with large proper motions ($\mu _{\rm tot} \gt 40.0~\rm mas\, yr^{-1}$) in the Gaia Early Data Release 3. We derive photometric metallicity calibrated from the colour–luminosity–metallicity distribution of 20 047 stars with spectroscopic metallicities, collected from various spectroscopic surveys, including SDSS SEGUE/APOGEE, GALAH DR3, and LAMOST DR6. We combine these results to construct an empirical colour–magnitude–metallicity grid, which can be used to estimate photometric metallicities for low-mass metal-poor stars of K and M subtypes from their absolute G magnitude and colour values. We find that low-mass, high-velocity stars in our catalogue share similar kinematics as reported in recent studies of more luminous Galactic halo stars. The pseudo-kinematic analysis of our sample recovers the main local halo structures, including the Gaia–Enceladus Stream and the Helmi stream; aside from these, the local halo stars appear to show a remarkably smooth distribution in velocity space. Since the future Gaia data release will provide radial velocity measurements for only a small number of our sample, our catalogue provides targets of high interest for the future spectroscopic observation programs.

Characterizing epochs of star formation across the Milky Way disc using age–metallicity distributions of GALAH stars

ABSTRACT We provide a detailed map of the ages and metallicities of turn-off stars in the Milky Way disc based on data from GALAH DR3 and Gaia EDR3. From this map, we identify previously undetected features in the age–metallicity distribution of disc stars and interpret these results as indicating a three-phase formation history of the Milky Way. In the first phase, inner disc stars form along a single age–metallicity sequence and are today kinematically hot. The end of this phase is marked by a local minimum in the inner disc age distribution 10 Gyr ago. At this time, we find the stellar populations to transition from high to low alpha-element abundances and from high to low vertical velocity dispersion. In the second phase, stars form across the disc with outwardly decreasing metallicity. In this phase, inner disc stars form at supersolar metallicities in a continuation of the early age–metallicity relation, while outer disc stars begin forming at metallicities at least 0.5 dex lower. Finally, the third phase is associated with a recent burst of star formation across the local disc marked by a local minimum in the age–metallicity distribution 4–6 Gyr ago. Future quantitative comparisons between the observed age–metallicity distribution and those of simulated galaxies could help constrain the processes driving each of the star formation phases.

Patient Satisfaction with Implant Removal after Stabilization Using Percutaneous Pedicle Screws for Traumatic Thoracolumbar Fracture.

Context:There are no reports of patient satisfaction with implant removal after stabilization using percutaneous pedicle screws (PPS) for traumatic thoracolumbar fracture (TTF).Aims:The aim of this study was to investigate patient satisfaction with implant removal after stabilization using PPS for TTF.Settings and Design:A retrospective study.Subjects and Methods:The present study included data from 24 patients who underwent posterior stabilization using PPS for single-level TTF following implant removal. The degree of patient satisfaction was evaluated using a questionnaire. We investigated residuary back pain, using the numerical rating scale (NRS) and Oswestry disability index (ODI), and types of occupation. Patients were divided into groups of those with residuary back pain (Group P) and those without (Group N). We evaluated local kyphosis and disc degeneration after implant removal. We investigated whether residuary back pain or types of occupation affect patient satisfaction.Statistical Analysis Used:All statistical analyses were conducted using IBM SPSS statistics.Results:Patients were “extremely satisfied” in 13 cases (54%), “moderately satisfied” in eight cases (33%), and “neither” in three cases (13%). No patients answered “moderately dissatisfied” or “extremely dissatisfied.” The mean scores on the NRS and ODI in Group P were 1.8 ± 0.9 and 13.2 ± 9.3, respectively. Patient satisfaction, disc degeneration, and local kyphosis were not significantly different between Group P and Group N. Patient satisfaction was not significantly different between the hard and light workgroups.Conclusions:Patient satisfaction with implant removal was high regardless of whether persistent back pain existed and did not depend on the type of occupation.

Voice and Face Recognition for Web Browser Security

Abstract: This paper analysis about browser privacy multimodal authentication mechanisms. Face and voice recognition will be used as authentication methods in this process. The OpenCV library is used in the framework's face recognition section. It detects and recognizes faces from a database using basic eigen face recognition approaches. The MFCC (Mel Frequency Cepstrum Coefficients) and Gaussian Mixture Model are used to recognize voices. Following successful authentication, the cookies on the local hard disc are decrypted, allowing us access to the browser cookies. Initially, after a user registers, we will encrypt the browser cookies with AES, one of the most secure encryption methods available. keywords: MFCC, Gaussian Mixture Model, Browser cookies, authentication, AES, encryption, decryption, Open CV, Eigen.

Forced Linear Shear Flows with Rotation: Rotating Couette–Poiseuille Flow, Its Stability, and Astrophysical Implications

Abstract We explore the effect of forcing on the linear shear flow or plane Couette flow, which is also the background flow in the very small region of the Keplerian accretion disk. We show that depending on the strength of forcing and boundary conditions suitable for the systems under consideration, the background plane shear flow, and hence the accretion disk velocity profile, is modified into parabolic flow, which is a plane Poiseuille flow or Couette–Poiseuille flow, depending on the frame of reference. In the presence of rotation, the plane Poiseuille flow becomes unstable at a smaller Reynolds number under pure vertical as well as three-dimensional perturbations. Hence, while rotation stabilizes the plane Couette flow, the same destabilizes the plane Poiseuille flow faster and hence the forced local accretion disk. Depending on the various factors, when the local linear shear flow becomes a Poiseuille flow in the shearing box due to the presence of extra force, the flow becomes unstable even for Keplerian rotation, and hence turbulence will ensue. This helps to resolve the long-standing problem of subcritical transition to turbulence in hydrodynamic accretion disks and the laboratory plane Couette flow.

A super-resolution analysis of the DSHARP survey: Substructure is common in the inner 30 au

Abstract The DSHARP survey evidenced the ubiquity of substructure in the mm dust distribution of large, bright protoplanetary discs. Intriguingly, these datasets have yet higher resolution information that is not recovered in a CLEAN image. We first show that the intrinsic performance of the CLEAN algorithm is resolution-limited. Then analyzing all 20 DSHARP sources using the 1D, super-resolution code Frankenstein (frank), we accurately fit the 1D visibilities to a mean factor of 4.3 longer baseline than the Fourier transform of the CLEAN images and a factor of 3.0 longer baseline than the transform of the CLEAN component models. This yields a higher resolution brightness profile for each source, identifying new substructure interior to 30 au in multiple discs; resolving known gaps to be deeper, wider, and more structured; and known rings to be narrower and brighter. Across the survey, high contrast gaps are an average $14{{\ \rm per\ cent}}$ wider and $44{{\ \rm per\ cent}}$ deeper in the frank profiles relative to CLEAN, and high contrast rings are an average $26{{\ \rm per\ cent}}$ narrower. Categorizing the frank brightness profiles into trends, we find that the relative scarcity of features interior to 30 au in the survey’s CLEAN images is an artefact of resolving power, rather than an intrinsic rarity of inner disc (or compact disc) substructure. Finally the rings in the frank profiles are narrower than the previously inferred deconvolved widths, indicating smaller α/St ratios in the local gas disc.

Cosmic-Ray Transport in Simulations of Star-forming Galactic Disks

Abstract Cosmic-ray transport on galactic scales depends on the detailed properties of the magnetized, multiphase interstellar medium (ISM). In this work, we postprocess a high-resolution TIGRESS magnetohydrodynamic simulation modeling a local galactic disk patch with a two-moment fluid algorithm for cosmic-ray transport. We consider a variety of prescriptions for the cosmic rays, from a simple, purely diffusive formalism with constant scattering coefficient, to a physically motivated model in which the scattering coefficient is set by the critical balance between streaming-driven Alfvén wave excitation and damping mediated by local gas properties. We separately focus on cosmic rays with kinetic energies of ∼1 GeV (high-energy) and ∼30 MeV (low energy), respectively important for ISM dynamics and chemistry. We find that simultaneously accounting for advection, streaming, and diffusion of cosmic rays is crucial for properly modeling their transport. Advection dominates in the high-velocity, low-density hot phase, while diffusion and streaming are more important in higher-density, cooler phases. Our physically motivated model shows that there is no single diffusivity for cosmic-ray transport: the scattering coefficient varies by four or more orders of magnitude, maximal at density n H ∼ 0.01 cm−3. The ion-neutral damping of Alfvén waves results in strong diffusion and nearly uniform cosmic-ray pressure within most of the mass of the ISM. However, cosmic rays are trapped near the disk midplane by the higher scattering rate in the surrounding lower-density, higher-ionization gas. The transport of high-energy cosmic rays differs from that of low-energy cosmic rays, with less effective diffusion and greater energy losses for the latter.

The diffuse interstellar band around 8620 Å

Context.Diffuse interstellar bands (DIBs) are important interstellar absorption features of which the origin is still debated. With the large data sets from modern spectroscopic surveys, background stars are widely used to show how the integrated columns of DIB carriers accumulate from the Sun to great distances. To date, studies on the kinematics of the DIB carriers are still rare.Aims.We aim to make use of the measurements from the Giraffe Inner Bulge Survey (GIBS) and theGaia–ESO survey (GES) to study the kinematics and distance of the carrier of DIBλ8620, as well as other properties.Methods.The DIBs were detected and measured following the same procedures as in Zhao et al. (2021, A&A, 645, A14; hereafter Paper I), assuming a Gaussian profile. The median radial velocities of the DIB carriers in 38 GIBS and GES fields were used to trace their kinematics, and the median distances of the carriers in each field were estimated by the median radial velocities and two applied Galactic rotation models.Results.We successfully detected and measured DIBλ8620 in 760 of 4117 GES spectra with |b| ≤ 10° and signal-to-noise ratio (S∕N) > 50. Combined with the DIBs measured in GIBS spectra (Paper I), we confirmed a tight relation between EW andE(J−KS) as well asAV, with similar fitting coefficients to those found by previous works. With a more accurate sample and the consideration of the solar motion, the rest-frame wavelength of DIBλ8620 was redetermined as 8620.83 Å, with a mean fit error of 0.36 Å. We studied the kinematics of the DIB carriers by tracing their median radial velocities in each field in the local standard of rest (VLSR) and into the galactocentric frame (VGC), respectively, as a function of the Galactic longitudes. Based on the medianVLSRand two Galactic rotation models, we obtained valid kinematic distances of the DIB carriers for nine GIBS and ten GES fields. We also found a linear relation between the DIBλ8620 measured in this work and the near-infrared DIB in APOGEE spectra at 1.5273 μm, and we estimated the carrier abundance to be slightly lower compared to the DIBλ15273.Conclusions.We demonstrate that the DIB carriers can be located much closer to the observer than the background stars based on the following arguments: (i) qualitatively, the carriers occupy in the Galactic longitude–velocity diagram typical rotation velocities of stars in the local Galactic disk, while the background stars in the GIBS survey are mainly located in the Galactic bulge; (ii) quantitatively, all the derived kinematic distances of the DIB carriers are smaller than the median distances to background stars in each field. A linear correlation between DIBλ8620 and DIBλ15273 has been established, showing similar carrier abundances and making them both attractive for future studies of the interstellar environments.

A Just-in-Time Mechanism for Computer System

As the installed programs will consume increasing space of hard disk, the computer becomes more and more bulky and costly. However, it’s harder and harder to make a larger yet still light and cheap hard disk. Therefore, computers used in most occasions are suggested to cancel their hard disks, and have their operating system programs and the application programs ‘installed’ on internet, instead of being installed on local hard disk. The data is accessed via supper high speed internet when the program booting. The operating system additionally serves as an open platform for registering the application software as well as the traditional role. This mechanism will bring us many gains. First, the user will no longer be restricted by the limited storage space, and will literarily have a never discarded and unlimited storage space that is shared by his or her all intelligent terminals. Second, the computers can become lighter and therefore easier to carry. Third, the user can get the latest version program once he or she launches the program. Last, the program provider can take the initiative to push the newest message to its users easily if they have subscribed.

Research on the Application of UAV Wide-angle Shooting Technology in Multimedia Video Playing

Unmanned aerial vehicles continue to increase the requirements for image resolution in the fields of reconnaissance, surveying, and mapping. The fusion of the video image system and the traditional remote control and telemetry system also needs to be considered in the design. Aiming at the above problems, the article designs and implements an airborne high-definition video image system based on FPGA+DSP. The system can store the video image on the local hard disk, and at the same time, the compressed video image is also convenient for real-time transmission to the ground control station through the wireless link equipment. The system detection found that the buffer occupancy can fluctuate smoothly in a small range, and the subjective image quality has also been improved, which better meets the low-latency application requirements of the airborne reconnaissance system.

Orbital eccentricities as indicators of stellar populations

Context.In previous work, we showed how the planar and vertical eccentricities of disc stars,eande′, could be used as indicators of the stars’ kinematic populations. For a local stellar sample drawn from theGaiaDR2 catalogue, these populations were represented geometrically in the eccentricity diagram,e′2vs.e2, approximately separated by straight lines.Aims.In the current work, we propose a new relationship between the star’s perpendicular velocity and its vertical eccentricity, allowing for a reevaluation of the critical vertical eccentricity and maximum height,zmax, specific to each population component.Methods.We approximated the local potential function to be consistent with the actual shape of the curve that relates the maximum vertical speed of a star and its maximum height. The curve corresponds to a non-linear restoring vertical force, where the stiffness decreases with an increase in the maximum height. The constants involved in this fitting, together with the population velocity dispersions, determine the specific region for each population in the eccentricity diagram.Results.The new classification determines 88% of the sample is made up of thin disc stars and 9% of thick disc stars, whereby 3% of the stars have been relabelled, by providing thinner thin and thick discs. Nested thin disc subsamples allow us to estimate Strömberg’s asymmetric drift equation, leading to a heliocentric velocity of the circular orbit ofVc ≈ −12.9 km s−1, an absolute rotation velocity of Θc ≈ 227 km s−1, and a rotation component of the Galactocentric velocity of the Sun at Θ⊙ ≈ 240 km s−1.Conclusions.The thin disc stars of our local sample are characterised based on values 0 ≤ e ≤ 0.32, 0 ≤ e′ ≤ 0.09, andzmax = 0.7 kpc. Disc stars satisfy 0 ≤ e ≤ 0.44, 0 ≤ e′ ≤ 0.18,zmax = 1.5 kpc. The maximum vertical peculiar velocity for disc stars is found to bew0 = 115 km s−1. The assumed potential provides a stellar density of the disc vanishing atz0 = 1.8 kpc. The approximate behaviour in the local disc is that a small decrease in the stiffness is associated with a relative decrease in the limiting velocity, which produces a thinner disc and a loss of stars in the local cylinder, both in a similar proportion to the limiting velocity.

Data-Taking Network for COMET Phase-I

An experiment to search for mu-e conversion named COMET is being constructed at J-PARC. The experiment will be carried out using a two-stage approach of Phase-I and Phase-II. The data taking system of Phase-I is developed based on common network technology. The data taking system consists of two kinds of networks. One is a front-end network. Its network bundles around twenty front-end devices that have a 1-Gb optical network port. And a front-end computer accepts data from the devices via its network. The other is a back-end network that collects all event fragments from the front-end computers using a 10-Gb network. We used a low price 1Gb/10Gb optical network switch for the front-end network. And direct connection between the front-end PC and an event building PC using 10-Gb optical network devices was used for the back-end network. The event building PC has ten 10-Gb network ports. And each network port of the event building PC is connected to the front-end PC's port without using a network switch. We evaluated data taking performance with an event building on these two kinds of networks. The event building throughput of the front-end network achieved 337 MiB/s. And the event building throughput of the back-end networks achieved 1.2 GiB/s. It means that we could reduce the construction cost of the data taking network using this structure without deteriorating performance. Moreover, we evaluated the writing speed of the local storage RAID disk system connected to a back-end PC by a SAS interface, and a long-distance network copy from the experiment location to the lasting storage.

Transcriptome annotation in the cloud: complexity, best practices and cost

BACKGROUND The NIH Science and Technology Research Infrastructure for Discovery, Experimentation, and Sustainability (STRIDES) initiative provides NIH-funded researchers cost-effective access to commercial cloud providers, such as Amazon Web Services (AWS) and Google Cloud Platform (GCP). These cloud providers represent an alternative for the execution of large computational biology experiments like transcriptome annotation, which is a complex analytical process that requires the interrogation of multiple biological databases with several advanced computational tools. The core components of annotation pipelines published since 2012 are BLAST sequence alignments using annotated databases of both nucleotide or protein sequences almost exclusively with networked on-premises compute systems. FINDINGS We compare multiple BLAST sequence alignments using AWS and GCP. We prepared several Jupyter Notebooks with all the code required to submit computing jobs to the batch system on each cloud provider. We consider the consequence of the number of query transcripts in input files and the effect on cost and processing time. We tested compute instances with 16, 32, and 64 vCPUs on each cloud provider. Four classes of timing results were collected: the total run time, the time for transferring the BLAST databases to the instance local solid-state disk drive, the time to execute the CWL script, and the time for the creation, set-up, and release of an instance. This study aims to establish an estimate of the cost and compute time needed for the execution of multiple BLAST runs in a cloud environment. CONCLUSIONS We demonstrate that public cloud providers are a practical alternative for the execution of advanced computational biology experiments at low cost. Using our cloud recipes, the BLAST alignments required to annotate a transcriptome with ∼500,000 transcripts can be processed in <2 hours with a compute cost of ∼$200-$250. In our opinion, for BLAST-based workflows, the choice of cloud platform is not dependent on the workflow but, rather, on the specific details and requirements of the cloud provider. These choices include the accessibility for institutional use, the technical knowledge required for effective use of the platform services, and the availability of open source frameworks such as APIs to deploy the workflow.

Lumbar Disc Prolapse: Microdiscectomy and its Clinical Outcomes

Background: Prolapse lumbar intervertebral disc (PLID) is a localized disc displacement outside its margins is the most common source of sciatica pain, involving 1%-5% of the population annually. Standard management includes conservative management initially for a period of around 6 weeks. In general, microdiscectomy (MD) is considered a standard procedure for symptomatic cases, with approximately 60%-80% of satisfactory results. In this study, we aimed in describing experience of MD in patients diagnosed with PLID. Methods: This retrospective study has been conducted at Dr. Ziauddin University hospital, Karachi; Pakistan. The medical records from 2018 to 2020, of microdiscectomy for prolapsed intervertebral lumbar disc were studied. All patients of 18 years or more admitted with symptomatic PLID, and proceeded to single level MD have been included. The regular pre-operative work-up, surgical technique and post-operative management was followed. Data collection was performed using a standard proforma. Utilizing SPSS version 23.0, all statistical analyses were carried out a p &lt;0.05 was considered statistically significant. Results: Mean age of patients was 43 to 42 years and Male: Female ratio was 1.6:1 and pre-operative neurological deficit was observed in 28 (42.4%) patients. Most common affected disc spaces were L4-L5 35(53%) and L5-S1 26 (39.4%). Left side disc Prolapse was found more affected as 39(59.1%) cases reported among the total. Visual analog scale (VAS) score dropped from more than 5 to no pain after surgery. Conclusion: Microdiscectomy is a safe treatment in prolapsed intervertebral lumbar disc for patients with failed conservative therapy and reported excellent outcomes with earlier surgical intervention. Keywords: Discectomy; Intervertebral Disc Displacement; Radiculopathy.

Limits on Millimeter Continuum Emission from Circumplanetary Material in the DSHARP Disks

Abstract We present a detailed analysis for a subset of the high-resolution (∼35 mas, or 5 au) ALMA observations from the Disk Substructures at High Angular Resolution Project (DSHARP) to search for faint 1.3 mm continuum emission associated with dusty circumplanetary material located within the narrow annuli of depleted emission (gaps) in circumstellar disks. This search used the Jennings et al. frank modeling methodology to mitigate contamination from the local disk emission and then deployed a suite of injection–recovery experiments to statistically characterize point-like circumplanetary disks in residual images. While there are a few putative candidates in this sample, they have only marginal local signal-to-noise ratios and would require deeper measurements to confirm. Associating a 50% recovery fraction with an upper limit, we find that these data are sensitive to circumplanetary disks with flux densities ≳50–70 μJy in most cases. There are a few examples where those limits are inflated (≳110 μJy) owing to lingering nonaxisymmetric structures in their host circumstellar disks, most notably for a newly identified faint spiral in the HD 143006 disk. For standard assumptions, this analysis suggests that these data should be sensitive to circumplanetary disks with dust masses ≳ 0.001 – 0.2 M ⊕ . While those bounds are comparable to some theoretical expectations for young giant planets, we discuss how plausible system properties (e.g., relatively low host planet masses or the efficient radial drift of solids) could require much deeper observations to achieve robust detections.

Comparing the Inner and Outer Star-forming Complexes in the Nearby Spiral Galaxies NGC 628, NGC 5457, and NGC 6946 Using UVIT Observations

Abstract We present a far-UV (FUV) study of the star-forming complexes (SFCs) in three nearby galaxies using the Ultraviolet Imaging Telescope. The galaxies are close to face-on and show significant outer disk star formation. Two of them are isolated (NGC 628 and NGC 6946), and one is interacting with distant companions (NGC 5457). We compared the properties of the SFCs inside and outside the optical radius (R 25). We estimated the sizes, star formation rates (SFRs), metallicities, and Toomre Q parameter of the SFCs. We find that the outer disk SFCs are at least 10 times smaller in area than those in the inner disk. The SFRs per unit area (ΣSFR) in both regions have similar mean values, but the outer SFCs have a much smaller range of ΣSFR. They are also metal-poor compared to the inner disk SFCs. The FUV emission is well correlated with the neutral hydrogen gas (H i) distribution and detected within and near several H i holes. Our estimation of the Q parameter in the outer disks of the two isolated galaxies suggests that their outer disks are stable (Q &gt; 1). However, their FUV images indicate that there is ongoing star formation in these regions. This suggests that there may be some nonluminous mass or dark matter in their outer disks, which increases the disk surface density and supports the formation of local gravitational instabilities. In the interacting galaxy, NGC 5457, the baryonic surface density is sufficient (Q &lt; 1) to trigger local disk instabilities in the outer disk.

Flow characteristics around extremely low fineness-ratio circular cylinders

We conduct wind tunnel experiments to evaluate the drag and base-pressure coefficients and velocity field in the wake of a circular cylinder with extremely low length-to-diameter (fineness) ratio for diameter-based Reynolds number in the range $2\ensuremath{-}7.7\ifmmode\times\else\texttimes\fi{}{10}^{4}$. A magnetic suspension and balance system eliminates interference from support structures. We find that the drag coefficient converges monotonically to that of a local disk without a maximum at any fineness ratio in the 0.1-0.5 range. Large-eddy simulations at Re = $4\ifmmode\times\else\texttimes\fi{}{10}^{4}$ agree with the experiments.

Anterior hybrid construction of multilevel cervical disc disease and spondylotic spinal stenosis: surgical results and factors affecting adjacent segment problems

ObjectiveWe aimed to evaluate reliability, radiological outcomes, and the impacts of anterior cervical hybrid construction on the adjacent segments for the multilevel cervical degenerative disc disease (mCDDD) and spondylotic spinal stenosis (SSS).MethodsA retrospective analysis was performed using data extracted from the medical files of 195 patients (105 males, 90 females; mean age: 47.7 years). From 2008 to 2018, these patients underwent anterior cervical hybrid construction for symptomatic contiguous at least 2-level cervical degenerative disc diseases and cervical spondylosis. Clinical and radiological data including Neck Disability Index (NDI), visual analogue scale (VAS), local cervical degenerative disk disease in adjacent segments on magnetic resonance imaging (MRI) views, and complications were reviewed.ResultsThe mean clinical and radiological follow-up was 45.2 months (range 24 to 102). Radiculopathy and/or myelopathy were the main clinical problems in all patients. The mean VAS scores of HC for arm pain were 7.4 ± 0.8 preoperatively; 2.8 ± 0.6, 1 month after surgery; 2.3 ± 0.6, 6 months after surgery; 1.8 ± 0.6, 12 month after surgery; and 1.6 ± 0.6, 24 months after surgery. The mean NDI scores (mean ± SD) of HC significantly improved after surgery (on admission, 57.2 ± 5.5%; 1 month after surgery, 27.35 ± 5.3%; 6 month after surgery, 21.43 ± 2.8%; 12 months after surgery, 21.9 ± 2.3%; 24 months after surgery, 20.6 ± 2.6%, p = 0.006). Hoarseness and dysphagia were the most common complications and osteophyte formation was the most frequent radiographic change.ConclusionAnterior cervical hybrid construction appears to be an acceptable option in the management of multilevel cervical degenerative disc diseases and spondylotic spinal stenosis.

Local stellar kinematics and Oort constants from the LAMOST A-type stars

ABSTRACT We estimate the solar peculiar velocities and Oort constants using a sample of 5627 A-type stars with $d\lt 0.6\, \rm kpc$ and $|z|\lt 0.1\, \rm kpc$, selected from the LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope) surveys. The radial and tangential velocities of these A-type stars are fitted by using a non-axisymmetric model. The best-fitting result yields the solar peculiar velocities $(U_\odot ,V_\odot ,W_\odot)=(11.69\pm 0.68, 10.16\pm 0.51, 7.67\pm 0.10)\, \rm km\, s^{-1}$ and Oort constants $A=16.31\pm 0.89\, \rm km\, s^{-1}\, kpc^{-1}$, $B=-11.99\pm 0.79\, \rm km\, s^{-1}\, kpc^{-1}$, $C=-3.10\pm 0.48\, \rm km\, s^{-1}\, kpc^{-1}$, and $K=-1.25\pm 1.04\, \rm km\, s^{-1}\, kpc^{-1}$. $|K+C|\gt 4\, \rm km\, s^{-1}\, kpc^{-1}$ means that there is a radial velocity gradient in the extended local disc, implying that the local disc is in a non-asymmetric potential. Using the derived Oort constants, we derive the local angular velocity $\Omega \, {\approx }\, A-B=28.30\pm 1.19\, \rm km\, s^{-1}\, kpc^{-1}$. By using A-type star sample of different volumes, we further try to evaluate the impacts of the ridge pattern in the R–Vϕ plane on constraining the solar motions and Oort constants. As the volume becomes larger towards the anticentre direction, the values of A and B become larger (implying a steeper slope of the local rotation curve) and the value of V⊙ becomes smaller probably caused by the ridge structure and its signal increasing with distance.