Portion Of Disk Research Articles

High-precision spectral inversions: Determining what is important for the accurate definition of incident radiation boundary conditions

Context. Spectral inversions are used to analyse spectroscopic observations with the aim of deriving the physical properties of the observed plasma, such as the kinetic temperature, density, pressure, degree of ionisation, or macroscopic velocities. One of the key factors ensuring the high precision of the derived plasma properties is having accurately defined input parameters of the models on which spectral inversions rely. The illumination, which chromospheric and coronal structures receive from the solar surface (and corona), is one of the most crucial input parameters of these models. Aims. We do not perform spectral inversions in this work. Our aim is to study two important factors that contribute to the accurate definition of the incident radiation boundary conditions: the altitude above the solar surface and the dynamics of the illuminated plasma. This investigation takes into account a diverse range of solar structures from the high-rising eruptive prominences to low-lying spicules. Methods. To study the influence of the altitude and dynamics of the observed plasma on the incident radiation boundary conditions, we used geometrical principles valid for any spectral line. However, to demonstrate the strong impact of dynamics, we considered the specific case of narrow spectral lines of Mg II H&K, which are highly sensitive to the presence of velocities. Results. We argue that the altitude of the illuminated plasma strongly influences the way we need to define the incident radiation boundary conditions to achieve the most accurate results. For low-lying structures, generally below 50 000 km, the incident radiation may need to be specified directly from the composition of the portion of the solar disc that illuminates them. For high-altitude structures, generally above 300 000 km, the fraction of the solar disc illuminating the analysed plasma is large enough to be realistically approximated by the composition of the entire disc. We also show that for the narrow spectral lines, such as the Mg II H&K lines, the impact of dynamics on the incident radiation intensity and profile shapes starts from radial velocities of 30 km s−1. Such velocities are even exhibited by the fine structures of quiescent prominences and are easily exceeded in spicules or eruptive prominences. Conclusions. The two aspects of the incident radiation definition studied here are relevant for spectral inversions based on any kind of modelling approach. However, their impact on the precision of the results of spectral inversions is likely less significant than the impact of the choice of the complexity of the model geometry, for example.

An Independent Hybrid Imaging of Sgr A* from the Data in EHT 2017 Observations

Abstract We propose that the ring structure found by the Event Horizon Telescope Collaboration (EHTC) as the black hole shadow of Sgr A* is an artifact by the bumpy PSF (Point Spread Function) of the EHT2017. The imaging using sparse u-v data requires detailed scrutiny of the PSF. The estimated shadow diameter ($\mathrm{48.7\pm 7~\mu \rm as}$) is equal to the spacing between the main beam and the first sidelobe of the PSF ($\mathrm{49.09~\mu \rm as}$), which immediately suggests a potential problem in the deconvolution of the PSF. We show that the ring image can be derived from non-ring simulated datasets (noise only; point source) with a narrow Field-of-View (FOV) and an assumed self-calibration suggesting the EHT2017’s u-v coverage is insufficient for reliable imaging. The EHTC analysis, based on calibrations with assumptions about the source’s size and properties, selected the final image by prioritizing appearance rate of the similar structure from a large imaging parameter space over data consistency. Our independent analysis with the conventional hybrid mapping reveals an elongated east-west structure, consistent with previous observations. We believe it to be more reliable than the EHTC image, due to half the residuals in normalized visibility amplitude. The eastern half is brighter, possibly due to a Doppler boost from the rapid rotating disk. We hypothesize our image shows a portion of the accretion disk about 2 to a few RS away from the black hole, rotating with nearly $\mathrm{60~\%}$ of the speed of light viewed from an angle of 40 − 45○.

Disentanglement of the chemodynamical assembly: mapping the Milky Way discs

ABSTRACT The formation and structure of the Milky Way have a fundamental role in our understanding of the universe and its evolution, and thanks to the Gaia mission and large spectroscopic surveys, we live an exceptional moment of data availability, allowing us to trace the building blocks of the Galactic disc and their relations. In this sense, we propose here the exploration of a large data set in a top-down fashion, elaborating a similarity map of the local Galactic volume in order to segregate and characterize its main components, searching for hints about their relations. We have used the t-SNE algorithm with chemical, orbital and kinematic properties of the stars to produce 2D manifolds and dissect their structure by isolating populations to further analyse their behaviour. The young thin disc could be clearly separated from the older thick disc, also showing a puzzling transition zone with hints about the aftermath of the Gaia–Sausage–Enceladus merger. Moving groups and resonant features also appear prominently in the maps, splitting the disc into inner and outer portions as consequence of the resonances produced by the Galactic bar. The dynamical halo appears as an extreme end related to the heated portion of the thick disc, showing sub-structures corresponding to known accreted populations. Open and globular clusters also appear in their chemical/evolutionary context. We present details of the developed strategy, an overview of the different populations and their relations, as well as a discussion and insights of our results in the scenario of Galactic evolution.

A New Study on the Effect of the Partial Wake Generated in a Wind Farm

In this article, we present an investigative study on the often-overlooked partial wake phenomenon in previous studies concerning wind farm configurations. A partial wake occurs when a portion of the actuator disk of a downstream wind turbine is affected by the wake of another upstream turbine. This phenomenon occurs in addition to the full wake, where the entire upstream turbine is affected by the wake of the frontal turbine, also leading to a decrease in wind speed and consequently a reduction in power production. The proposed study is based on measuring the power generated by the area swept by the wake of an array of turbines in a wind farm. To accomplish this, we integrate the linear wake model of Jensen, the specifications of the ENERCON E2 wind turbine, and the wind farm data into Matlab-developed software (version 18) to perform the calculations. In a concrete application, this proposed method is validated by reproducing the previous works that neglected the partial wake in wind farm configurations. The simulation results obtained are analyzed, compared, and discussed under similar operational conditions.

Right disc thrombosis of the new Gore Cardioform ASD Occluder.

The GCA is a well performing device in terms of efficacy despite complex anatomies (aortic rim <5 mm and ASD diameter >17 mm) with a good safety profile. To evaluate atrial septal defect (ASD) features impacting on right disc device thrombosis in patients who underwent Gore Cardioform ASD Occluder (GCA) implantation. A total of 44 consecutive patients undergoing percutaneous ASD with GCA device from January 2020 to September 2022 at our tertiary care Center were evaluated. The minimum follow-up was 6 months. The patients were stratified in two groups according to a cut-off value of ASD diameter equal to 20 mm at sizing balloon, derived from ROC analysis (AUC = 0.894; p = 0.024). Baseline characteristics were comparable between groups in terms of age, sex, weight, height, and interatrial septum dimensions. Patients with ASD > 20 mm (n = 9) had a higher ASD/device dimension ratio, both at echocardiography (p = 0.009) and at sizing balloon (p = 0.001), longer fluoroscopic time (p = 0.022), and higher incidence of device thrombosis (0.006). Right disc thrombosis was observed in three patients of the ASD > 20 mm group, always in the inferior portion of the right disc. On univariate analysis, ASD diameter at sizing balloon (OR 1.360; p = 0.036) was the only positive predictor of device thrombosis. Right disc thrombosis of the GCA device may be under-recognized at follow-up, hence deserving clinical attention, especially in those patients with larger ASD diameters.

Sweeping secular resonances and giant planet inclinations in transition discs

ABSTRACT The orbits of some warm Jupiters are highly inclined (20°–50°) to those of their exterior companions. Comparable misalignments are inferred between the outer and inner portions of some transition discs. These large inclinations may originate from planet–planet and planet–disc secular resonances that sweep across interplanetary space as parent discs disperse. The maximum factor by which a seed mutual inclination can be amplified is of the order of the square root of the angular momentum ratio of the resonant pair. We identify those giant planet systems (e.g. Kepler-448 and Kepler-693) that may have crossed a secular resonance, and estimate the required planet masses and semimajor axes in transition discs needed to warp their innermost portions (e.g. in CQ Tau). Passage through an inclination secular resonance could also explain the hypothesized large mutual inclinations in apsidally-orthogonal warm Jupiter systems (e.g. HD 147018).

Doppler confirmation of TESS planet candidate TOI−1408.01: grazing transit and likely eccentric orbit

ABSTRACT We report an independent Doppler confirmation of the TESS planet candidate orbiting an F-type main-sequence star TOI−1408 located 140 pc away. We present a set of radial velocities obtained with a high-resolution fibre-optic spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our self-consistent analysis of these Doppler data and TESS photometry suggests a grazing transit such that the planet obscures its host star by only a portion of the visible disc. Because of this degeneracy, the radius of TOI−1408.01 appears ill-determined with lower limit about ∼1 RJup, significantly larger than in the current TESS solution. We also derive the planet mass of 1.69 ± 0.20 MJup and the orbital period ∼4.425 d, thus making this object a typical hot Jupiter, but with a significant orbital eccentricity of 0.259 ± 0.026. Our solution may suggest that the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding, or may indicate possible presence of other unseen companions in the system, yet to be detected.

Comparing clinical outcomes of dogs suffering from degenerative lumbosacral stenosis upon surgical or nonsurgical treatment

PICO question In dogs suffering from degenerative lumbosacral stenosis (DLSS), is surgical treatment more effective than nonsurgical therapy in reducing lumbosacral pain and neurological dysfunction in the long-term? Clinical bottom line Category of research Treatment. Number and type of study designs reviewed Two papers were critically reviewed. They were prospective and retrospective studies. Strength of evidence Weak. Outcomes reported Besides the two studies, there are no other studies currently available that directly compare long-term clinical outcome of patients that have undergone nonsurgical and surgical treatment respectively. In the study comparing clinical outcome of nonsurgical treatment by epidural steroid injection (ESI) and surgical treatment of degenerative lumbosacral stenosis, dogs were classified into clinical severity groups ranging from mild to moderate to severe. Mild cases demonstrated degenerative lumbosacral stenosis (DLSS) compatible clinical signs such as lumbosacral pain, reluctance to climb stairs / jump / raise up, lameness and muscle atrophy but no neurological deficits. Moderate cases presented DLSS compatible clinical signs in combination with neurological deficits such as reduced flexor withdrawal, proprioceptive deficits and nerve root signature. Severe cases demonstrated DLSS compatible clinical signs with more severe neurological deficits such as tail paresis and absent perineal reflex. Clinical outcomes were considered complete if clinical signs had resolved at follow-up consultations, partial if there was substantial but incomplete improvement in clinical signs and failed if the dog did not improve or deteriorated further. Improvements in patient condition were measured in terms of clinical outcome grading which is in relation to the initial clinical severity group assigned to each dog. Improvement after single dose of ESI was seen in 27/32 dogs, with 17/22 (after accounting for four dogs whose owners have refused further treatment, five dogs lost to follow-up after re-check as well as one dog whose owners have opted for repeated ESI instillations) relapsing within 6 months. All 17 of these dogs that suffered a relapse after single ESI subsequently underwent surgical treatment and demonstrated improvement in clinical signs, with a complete response seen in eight dogs and a partial response seen in nine dogs. In the study comparing clinical outcome of conservative treatment of exercise restriction with phenylbutazone administration and surgical treatment of degenerative lumbosacral stenosis, outcomes were classified as good in dogs that regained preoperative activity levels; acceptable in dogs with persistent abnormality or requiring continued medication though otherwise active, and poor in all other cases. Out of 16 dogs treated surgically, 11 were treated by dorsal lumbosacral laminectomy and excision of the dorsal portion of the lumbosacral disc, while the other five had additional unilateral facetectomy to decompress the seventh lumbar nerve. Out of the 11 dogs treated with dorsal lumbosacral laminectomy and excision of the dorsal portion of the lumbosacral disc, 6/11 (54.5%) of dogs were deemed to have a good outcome, while 3/11 (27.3%) of dogs were deemed to have an acceptable outcome. Out of the five dogs treated with dorsal lumbosacral laminectomy and excision of the dorsal portion of the lumbosacral disc with additional unilateral facetectomy, 3/5 (60%) of dogs were deemed to have an acceptable outcome. The outcome of conservative treatment was deemed good in 8/16 (50%) of dogs in the conservative treatment group. Conclusion There is evidence suggesting that both nonsurgical and surgical treatments can improve clinical outcomes and reduce lower back pain and neurological deficits. However, based on the current limited literature, it cannot be ascertained whether surgical treatments are more effective than nonsurgical treatments in improving long-term clinical outcomes and vice versa. In the study that tested the efficacy of epidural steroid injection, only a single dose of steroids was given in this study, making it a potential reason for the high rate of relapse following nonsurgical treatment. For surgical treatment of DLSS, the type of surgical procedure chosen would also depend on the part of the lumbosacral region which fails and leads to compression. In conclusion, randomised controlled trials that compare different forms of nonsurgical treatment with surgical treatment for dogs with DLSS caused by different underlying factors need to be conducted to properly address the PICO question. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources. Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.

Photoactive intragastric satiety-inducing device using polymeric photosensitizers for minimally invasive weight loss treatment

An intragastric satiety-inducing device (ISD) located in the stomach induce satiety and fullness in the absence of food by continuously pressing on the distal esophagus and cardia of the stomach. To improve the therapeutic function of ISD, Chlorin e6 (Ce6) was embedded in a disk portion of ISD, generating reactive oxygen species and stimulating endocrine cells under the laser irradiation. Since Ce6 has remarkable light efficiency but poor solubility in various solvents, it is essential to use a polymeric photosensitizer and optimize a suitable coating solution composition. Methoxy polyethylene glycol-Ce6 was uniformly coated and the spontaneous release amount of the Ce6 from the device could be reduced, which induced photo-responsive cell death and reduced ghrelin levels in vitro. In mini pigs operated single therapy (PDT or ISD) or combination therapy (Photoreactive ISD), there were differences in body weight (control: 28% vs. Photoreactive ISD: 4%, P < 0.001), ghrelin (control: 4% vs. Photoreactive ISD: 35%, P < 0.001), and leptin levels (control: 8% vs. Photoreactive PDT: 35%, P < 0.001) at 4 weeks.

Did the Milky Way just light up? The recent star formation history of the Galactic disc

We map the stellar age distribution (≲1 Gyr) across a 6 kpc × 6 kpc area of the Galactic disc in order to constrain our Galaxy’s recent star formation history. Our modelling draws on a sample that encompasses all presumed disc O-, B-, and A-type stars (∼500 000 sources) with G &lt; 16. To be less sensitive to reddening, we did not forward-model the detailed CMD distribution of these stars; instead, we forward-modelled the K-band absolute magnitude distribution, n(MK), among stars with MK &lt; 0 and Teff &gt; 7000 K at certain positions x in the disc as a step function with five age bins, b(τ | x, α), logarithmically spaced in age from τ = 5 Myr to τ ∼ 1 Gyr. Given a set of isochrones and a Kroupa initial mass function, we sampled b(τ | x, α) to maximise the likelihood of the data n(MK | x, α), accounting for the selection function. This results in a set of mono-age stellar density maps across a sizeable portion of the Galactic disc. These maps show that some, but not all, spiral arms are reflected in overdensities of stars younger than 500 Myr. The maps of the youngest stars (&lt; 10 Myr) trace major star-forming regions. The maps at all ages exhibit an outward density gradient and distinct spiral-like spatial structure, which is qualitatively similar on large scales among the five age bins. When summing over the maps’ areas and extrapolating to the whole disc, we find an effective star formation rate over the last 10 Myr of ≈ 3.3 M⊙ yr−1, higher than previously published estimates that had not accounted for unresolved binaries. Remarkably, our stellar age distribution implies that the star formation rate has been three times lower throughout most of the last Gyr, having risen distinctly only in the very recent past. Finally, we used TNG50 simulations to explore how justified the common identification of local age distribution with global star formation history is: we find that the global star formation rate at a given radius in Milky Way-like galaxies is approximated within a factor of ∼1.5 by the young age distribution within a 6 kpc × 6 kpc area near R⊙.

Stellar feedback in M83 as observed with MUSE

Context. Young massive stars inject energy and momentum into the surrounding gas, creating a multi-phase interstellar medium (ISM) and regulating further star formation. The main challenge of studying stellar feedback proves to be the variety of scales spanned by this phenomenon, ranging from the immediate surrounding of the stars (H II regions, 10s pc scales) to galactic-wide kiloparsec scales. Aims. We present a large mosaic (3.8 × 3.8 kpc) of the nearby spiral galaxy M83, obtained with the MUSE instrument at ESO Very Large Telescope. The integral field spectroscopy data cover a large portion of the optical disk at a resolution of ∼20 pc, allowing the characterisation of single H II regions while sampling diverse dynamical regions in the galaxy. Methods. We obtained the kinematics of the stars and ionised gas, and compared them with molecular gas kinematics observed in CO(2-1) with the ALMA telescope array. We separated the ionised gas into H II regions and diffuse ionised gas (DIG) and investigated how the fraction of Hα luminosity originating from the DIG (fDIG) varies with galactic radius. Results. We observe that both stars and gas trace the galactic disk rotation, as well as a fast-rotating nuclear component (30″ ≃ 700 pc in diameter), likely connected to secular processes driven by the galactic bar. In the gas kinematics, we observe a stream east of the nucleus (50″ ≃ 1250 pc in size), redshifted with respect to the disk. The stream is surrounded by an extended ionised gas region (1000 × 1600 pc) with enhanced velocity dispersion and a high ionisation state, which is largely consistent with being ionised by slow shocks. We interpret this feature as either the superposition of the disk and an extraplanar layer of DIG, or as a bar-driven inflow of shocked gas. A double Gaussian component fit to the Hα line also reveals the presence of a nuclear biconic structure whose axis of symmetry is perpendicular to the bar. The two cones (20″ ≃ 500 pc in size) appear blue- and redshifted along the line of sight. The cones stand out for having an Hα emission separated by up to 200 km s−1 from that of the disk, and a high velocity dispersion ∼80–200 km s−1. At the far end of the cones, we observe that the gas is consistent with being ionised by shocks. These features had never been observed before in M83; we postulate that they are tracing a starburst-driven outflow shocking into the surrounding ISM. Finally, we obtain fDIG ∼ 13% in our field of view, and observe that the DIG contribution varies radially between 0.8 and 46%, peaking in the interarm region. We inspect the emission of the H II regions and DIG in ‘BPT’ diagrams, finding that in H II regions photoionisation accounts for 99.8% of the Hα flux, whereas the DIG has a mixed contribution from photoionisation (94.9%) and shocks (5.1%).

Pathomechanism of Lower-level Discogenic Groin Pain and Clinical Outcomes of Percutaneous Endoscopic Discectomy for the Treatment of Discogenic Groin Pain

Groin pain can be induced by high-level (L1-L2 or L2-L3) lumbar disc herniation. However, 4.1% of patients with lower-level (L4-L5 or L5-S1) lumbar disc herniation also complained of groin pain. The pathomechanism of groin pain occurring due to lumbar disc herniation at and below the L4-5 levels is still unclear. To investigate the afferent pathways of lower-level lumbar disc herniation induced groin pain. And evaluate the clinical results of transforaminal endoscopic discectomy treatment for discogenic groin pain. This retrospective observational study used an experimental design (institutional review board: HROH 201-C2-100). The research took place in the Laboratory Research Center and spine center at The First Affiliated Hospital of Harbin Medical University. Firstly, 14 adult Wistar rats were randomly divided into 2 groups: control group (the paravertebral sympathetic trunks were preserved) and experimental group (the paravertebral sympathetic trunks were resected). All Wistar rats were intraperitoneally anesthetized, and then 1 (mu)L of fast blue was injected into the dorsal rami of L2 spinal nerves on the right side. Forty hours later, 2 (mu)L of nuclear yellow was injected into the right posterior portion of the L5-L6 intervertebral disc. The L1 and L2 spinal ganglia were sectioned 8 hours later to observe fluorescently double-labeled cells and the effect of paravertebral sympathetic trunk resection. Secondly, 14 adult Wistar rats were anesthetized, and the right posterior portion of the L5-L6 intervertebral disc was electrostimulated to observe potential changes in the genitocrural nerve in the ipsilateral inguinal region. To evaluate the clinical outcomes of transforaminal endoscopic discectomy for the treatment of discogenic groin pain, between September 2015 and May 2017, transforaminal endoscopic discectomy was performed on 30 patients with lower-level discogenic groin pain. Outcomes were analyzed utilizing the visual analog scale, Oswestry disability index, and MacNab Criteria. The total proportion of cells in the right L1 and L2 spinal ganglia with fast blue/nuclear yellow double labeling was 3.33% and 3.41% (48 and 56), respectively. The number of fluorescently double-labeled cells in the resected paravertebral sympathetic trunk group was significantly less (P < 0.01). Electrical stimulation of the right posterior portion of the L5-L6 intervertebral disc could elicit action potentials in the ipsilateral genitofemoral nerve. All patients were followed for 12 months, and the visual analog scale score at 1 week, 1 month, 3 months, 6 months, and 12 months after the operation was 0.79 ± 0.55, 0.54 ± 0.55, 0.47 ± 0.65, 0.51 ± 0.65, and 0.69 ± 0.55, respectively, showing a significant decrease compared with the preoperative visual analog scale score (P < 0.01). Based on the MacNab scoring system, the effective rate was 100%, and the rate of good and excellent results was 93.3%. A relatively small number of patients and a short follow-up period. Discogenic groin pain is transmitted by sympathetic nerves and appears in the area segmentally innervated by the anterior rami of the L1 and L2 spinal nerves. Posterolateral percutaneous transforaminal endoscopic discectomy and radiofrequency thermal annuloplasty are effective minimally invasive alternative treatments for discogenic groin pain.

Thick Accretion Disk and Its Super Eddington Luminosity around a Spinning Black Hole

In the general accretion disk model theory, the accretion disk surrounding an astronomical object comprises fluid rings obeying Keplerian motion. However, we should consider relativistic and rotational effects as we close in toward the center of accretion disk surrounding spinning compact massive objects such as a black hole or a neutron star. In this study, we explore the geometry of the inner portion of the accretion disk in the context of Mukhopadhyay’s pseudo-Newtonian potential approximation for the full general relativity theory. We found that the shape of the accretion disk “puffs up” or becomes thicker and the luminosity of the disk could exceed the Eddington luminosity near the surface of the compact spinning black hole.

Magellanic Mayhem: Metallicities and Motions

Abstract We assemble a catalog of Magellanic Cloud red giants from Data Release 2 of the Gaia mission and, utilizing machine-learning methods, obtain photometric metallicity estimates for them. In doing so, we are able to chemically map the entirety of the Magellanic System at once. Our maps reveal a plethora of substructure within our red giant sample, with the Large Magellanic Cloud (LMC) bar and spiral arm being readily apparent. We uncover a curious spiral-like feature in the southern portion of the LMC disk, hosting relatively metal-rich giants and likely a by-product of historic encounters with the Small Magellanic Cloud (SMC). Modeling the LMC as an inclined thin disk, we find a shallow metallicity gradient of −0.048 ± 0.001 dex kpc−1 out to ∼12° from the center of the dwarf. We see evidence that the SMC is disrupting, with its outer isodensity contours displaying the S-shape symptomatic of tidal stripping. On studying the proper motions of the SMC giants, we observe a population of them being violently dragged toward the larger Cloud. The perturbed stars predominantly lie in front of the SMC, and we interpret that they exist as a tidal tail of the dwarf, trailing in its motion and undergoing severe disruption from the LMC. We find the metallicity structure in the Magellanic Bridge region to be complex, with evidence for a composite nature in this stellar population, consisting of both LMC and SMC debris.

Development of the Functional Gradient Turbine Wheel With Cooled Blades Without Lock Connection

Abstract The blisk design of the wheel with cooled blades is developed on the basis of the turbine wheel with a detachable connection of the blades with the disk. The blades of the blisk are produced from casting heat-resistant nickel alloy. The disk portion is created from granulated alloy with different grain sizes along the disk radius. The system of supplying cooling air in the blades of the wheel is developed. The technology of manufacturing a disk consisting of granules of various sizes and technology of connection of a disk with cooled cast blades is developed. To determine the mechanical characteristics of the zones of connection of dissimilar materials, samples were tested. Multiparameter optimization of the blisk was carried out. The mass of the designed wheel was reduced by more than 40% compared to the original wheel with lock connection when the strength and service life conditions were satisfied.

The formation of the cold classical Kuiper Belt by a short range transport mechanism

The Classical Kuiper Belt is populated by a group of objects with low inclination orbits, reddish colors and usually belonging to a binary system. This so called Cold Classical Kuiper Belt is considered to have been formed in situ from primordial ice pebbles that coagulated into planetesimals hundreds of kilometers in diameter. According to this scenario, the accretion of pebbles into large planetesimals would have occurred through the streaming instability mechanism that would be effective in the primordial Solar System disk of gas and solids. Nevertheless other objects with the same color characteristics as those found in the Cold Classical Kuiper Belt can be encountered also past the 2:1 mean motion resonance with Neptune as scattered or detached objects. Here I propose a mechanism that can account for both the cold Classical Kuiper Belt objects and other reddish objects outside the Classical Kuiper Belt. According to the proposed scenario, reddish objects were primordially in the outer portion of the planetesimal disk which was however truncated somewhere below ~42 au. In this manner the cold Classical Kuiper Belt and its scattered / detached counterpart were respectively transported outwards by a short range or slightly scattered to their present locations. Resonant objects were also formed by the same process. This mechanism is aimed at explaining the distribution of all objects that share the same color characteristics as coming from a common origin in the outer borders of the primordial planetesimal disk. According to the scenario here proposed the Cold Classical Kuiper Belt would have been formed ~4 au inside its present location with a total mass 20 − 100 times as large as its present value.

The effectiveness of chemonucleolysis with condoliase for treatment of painful lumbar disc herniation

BackgroundChemonucleolysis with condoliase, which degrades chondroitin sulfate, could be a new, minimally invasive therapeutic option for patients with lumbar disc herniation (LDH). The purpose of this study was to analyze prognostic factors for clinical outcomes in LDH patients subjected to chemonucleolysis with condoliase. MethodsInclusion criteria for this procedure were 1) 18–70 years of age; 2) unilateral leg pain and positive straight leg raise (SLR) (<70°) or femoral nerve stretching test; 3) subligamentous extrusion verified on magnetic resonance imaging; 4) neurological symptoms consistent with a compressed nerve root on magnetic resonance imaging (MRI) images; and 5) minimum six months of follow-up. In total, 82 patients (55 men, 27 women; mean age, 47.2 ± 15.5 years; mean follow-up, 9.1 ± 3.0 months) who underwent chemonucleolysis with condoliase for painful LDH were included. An improvement of 50% or more in the Visual analogue scale (VAS) of leg pain was classified as effective. ResultsSeventy patients (85.4%) were classified into the effective (E) group and 12 patients (14.6%) into the less-effective (L) group. Surgical treatment was required in four patients. No severe adverse complications were reported; 41.3% of the patients developed disc degeneration of Pfirrmann grade 1 or more at the injected disc level. Univariate analysis revealed that young age (p = 0.036), without history of epidural or nerve root block (p = 0.024), and injection into the central portion of the intervertebral disc (p = 0.014) were significantly associated with clinical effectiveness. A logistic regression analysis revealed that injection into the central portion of the intervertebral disc (p = 0.049; odds ratio, 4.913; 95% confidence interval, 1.006–26.204) was significantly associated with clinical effectiveness. ConclusionsChemonucleolysis with condoliase is a safe and effective treatment for painful LDH; 85.4% of the patients showed improvement after the treatment without severe adverse events. To obtain the best outcome, condoliase should be injected into the center of the intervertebral disc.

Analysis of Retinal Nerve Fibre Thickening in Progressive and Non-progressive Non-arteritic Anterior Ischaemic Optic Neuropathy Using Optical Coherence Tomography

ABSTRACT The study aims to investigate the longitudinal changes in the circumpapillary retinal nerve fibre layer thickness (cpRNFLT) in progressive and non-progressive non-arteritic anterior ischaemic optic neuropathy (NAION). This retrospective observational case series study analysed 17 eyes with NAION. Patients sustaining any additional visual loss (additional decrease in visual acuity (VA) ≥0.2 logMAR) within two months after initial onset of symptoms were classified as having progressive NAION. Of the 17 eyes with NAION, 13 (76.5%) were diagnosed as non-progressive and 4 (23.5%) were diagnosed as progressive. Compared with control eyes, eyes with non-progressive NAION showed greater cpRNFLT in all four optic disc quadrants at the initial visit (temporal and superior: P < .001; nasal and inferior: P = .002). In contrast, compared with control eyes, eyes with progressive NAION showed greater cpRNFLT in the superior and nasal quadrants (P = .004 and 0.028, respectively), but not in the temporal and inferior quadrants. During progression, eyes with progressive NAION showed a significant increase in cpRNFLT in the inferior quadrants; furthermore, there was significant increase in cpRNFLT in the nasal sector before visual loss developed after the initial visit. Progressive NAION showed development of the disc swelling from the superior to inferior portion of optic disc via the nasal swelling, suggesting that swollen axons in one ischaemic part may lead to secondary vascular infarction in another part of the optic disc. This enlargement could constitute the earliest sign of progressive NAION.

Endoscopic Anterior Cervical Discectomy (Disc Preserving).

Endoscopic anterior cervical approach has several advantages compared to conventional anterior cervical discectomy and fusion (ACDF). This video demonstrates a step-by-step procedure for endoscopic anterior cervical discectomy. The patient is placed supine with the neck extended. A standard anterior cervical approach using about 3 cm skin incision is made and under "Easy Go" (Karl Storz, Tuttlingen, Germany) endoscopic vision, the uncinate process and uncus are drilled. Only a small portion of the normal disc, posterior longitudinal ligament (PLL), and compressing disc is removed. The closure is done in a standard manner. In 240 patients, the average postoperative reduction in disc height, operating time, and blood loss were 1.1 ± 0.2 mm, 110 ± 17 min, and 30 ± 11 mL, respectively. The average postoperative VAS score and Nurick grading improved significantly. There were no permanent complications or any mortality. Endoscopic technique is an effective and safe alternative to ACDF after attaining the learning curve.

Sticky Trap Design Considerations for Entrapping Bed Bugs.

Little evidence has been presented on the usefulness of sticky traps for monitoring bed bugs, Cimex lectularius. We examined how the surface roughness around the adhesive of a sticky trap affects both bed bug behavior and adhesive entrapment. In the first assay, bed bugs were placed onto acetate paper discs with different roughness averages (Ra). Each disc was surrounded by sticky trap adhesive and number of captured bed bugs were recorded. The second assay was set up similarly to the first assay except that the outer portion of the acetate disc had a different Ra than the center. In the third assay, bed bugs were placed into circular acetate arenas where they were surrounded by different Ra treatments. The number of times the bed bugs contacted the Ra treatment but did not cross onto the treatment was recorded. Results of these assays showed that as the acetate surfaces got smoother (lower Ra), bed bugs were more likely to get trapped in sticky trap adhesives but also less likely to travel across the smoother surfaces they encountered. A sticky trap design with a smooth plastic film around the adhesive was tested in the field to see if it could capture bed bugs in apartments with known bed bug activity. This trap was not only able to capture bed bugs but was also able to detect unknown German cockroach, Blattela germanica, infestations. Sticky trap designs with smooth surfaces around an adhesive could be used to monitor not only bed bugs but also German cockroaches.