Anesthetic Considerations for Cervical Fusion Surgery in Advanced Rheumatoid Arthritis and Severe Pulmonary Hypertension

67 year-old female with a history of rheumatoid arthritis (RA) and pulmonary hypertension (PH) presented for urgent C4-C5 anterior diskectomy and C3-C6 posterior fusion for cervical subluxation. C-spine MRI showed severe cord impingement. The patient was brought to the operating room with minimal sedation to avoid exacerbation of PH. The radial artery was inaccessible due to flexion deformities, thus a brachial arterial line was placed. Awake fiberoptic intubation was performed with dexmedetomidine, followed by demonstration of movement of all four extremities. The anesthesia was maintained with dexmedetomidine and desflurane. The anterior and posterior portions of the procedure were performed uneventfully with no change in baseline somatosensory evoked potentials (SSEP) and motor evoked potentials (MEP). The patient was extubated at the end of the case and was followed in the intensive care unit (ICU) and was discharged to rehabilitation in good condition

Geophysical modelling of plate tectonic processes

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Soil-Transmitted Helminthiases: Implications of Climate Change and Human Behavior

Soil-transmitted helminthiases (STHs) collectively cause the highest global burden of parasitic disease after malaria and are most prevalent in the poorest communities, especially in sub-Saharan Africa. Climate change is predicted to alter the physical environment through cumulative impacts of warming and extreme fluctuations in temperature and precipitation, with cascading effects on human health and wellbeing, food security and socioeconomic infrastructure. Understanding how the spectrum of climate change effects will influence STHs is therefore of critical importance to the control of the global burden of human parasitic disease. Realistic progress in the global control of STH in a changing climate requires a multidisciplinary approach that includes the sciences (e.g. thermal thresholds for parasite development and resilience) and social sciences (e.g. behavior and implementation of education and sanitation programs)

Fitting Together the HI Absorption and Emission in the SGPS

In this paper we study 21-cm absorption spectra and the corresponding emission spectra toward bright continuum sources in the test region (326deg< l < 333 deg) of the Southern Galactic Plane Survey. This survey combines the high resolution of the Australia Telescope Compact Array with the full brightness temperature information of the Parkes single dish telescope. In particular, we focus on the abundance and temperature of the cool atomic clouds in the inner galaxy. The resulting mean opacity of the HI, , is measured as a function of Galactic radius; it increases going in from the solar circle, to a peak in the molecular ring of about four times its local value. This suggests that the cool phase is more abundant there, and colder, than it is locally. The distribution of cool phase temperatures is derived in three different ways. The naive, ``spin temperature'' technique overestimates the cloud temperatures, as expected. Using two alternative approaches we get good agreement on a histogram of the cloud temperatures, T(cool), corrected for blending with warm phase gas. The median temperature is about 65 K, but there is a long tail reaching down to temperatures below 20 K. Clouds with temperatures below 40 K are common, though not as common as warmer clouds (40 to 100 K). Using these results we discuss two related quantities, the peak brightness temperature seen in emission surveys, and the incidence of clouds seen in HI self-absorption. Both phenomena match what would be expected based on our measurements of and T(cool).Comment: 50 pages, 20 figure

Bow Hunter\u27s Syndrome in a Patient with a Right Hypoplastic Vertebral Artery and a Dynamically Compressible Left Vertebral Artery

This is a case report of a 48-year-old man with multiple transient ischemic attacks and a known hypoplastic right vertebral artery (VA) who presented after a syncopal event while turning his head to the left. The objective of this study is to demonstrate the necessity of proper diagnosis and management of cerebrovascular pathology including imaging and surgical intervention in patients with known anatomical anomalies. This study was conducted at Massachusetts, United States of America. Our patient\u27s history was significant for a hypoplastic right VA and a stenotic segment of the right VA at the C3-C4 junction. There was also degeneration of the C3-C4 facet on the left, with osteophyte formation compressing the VA, and a fusion of the C2-C3 segment. Imaging demonstrated obliteration of the left VA flow with head rotation to the left and subsequent reconstitution of flow in the neutral position. After consultation, the patient decided to proceed with surgical management with an anterior cervical discectomy and fusion at the level of C3-C4. Symptoms of vertebrobasilar insufficiency including syncopal episodes resolved after treatment. VA anomalies, although uncommon, are important to understand. Our patient presented with an anomalous right VA, as well as severe degenerative changes to the C2/C3 vertebrae that contributed to the development of Bow Hunter\u27s syndrome. It is essential that proper monitoring and follow-up has to be carried out in patients with abnormal cerebral vasculature to minimize the occurrence of Bow Hunter\u27s syndrome

X-ray imaging of the Seyfert 2 galaxy Circinus with Chandra

We present results from the zeroth-order imaging of a Chandra HETGS observation of the nearby Seyfert 2 galaxy Circinus. Twelve X-ray sources were detected in the ACIS-S image of the galaxy, embedded in diffuse X-ray emission. The latter shows a prominent (~18arcsec) soft ``plume'' in the N-W direction, coincident with the [OIII] ionization cone. The radial profiles of the brightest X-ray source at various energies are consistent with an unresolved (FWHM ~0.8arcsec) component, which we identify as the active nucleus, plus two extended components with FWHMs ~ 2.3arcsec and 18arcsec, respectively. In a radius of 3arcsec, the nucleus contributes roughly the same flux as the extended components at the softest energies (< 2 keV). However, at harder energies (> 2 keV), the contribution of the nucleus is dominant. The zeroth-order ACIS spectrum of the nucleus exhibits emission lines at both soft and hard X-rays, including a prominent Fe Kalpha line at 6.4 keV, showing that most of the X-ray lines previously detected with ASCA originate in a compact region (<15 pc). Based on its X-ray spectrum, we argue that the 2.3arcsec extended component is scattered nuclear radiation from nearby ionized gas. The large-scale extended component includes the emission from the N-W plume and possibly from the outer starburst ring.Comment: Figure 1 in color. ApJ Letters, in pres

Localization of Light: Dual Symmetry between Absorption and Amplification

We study the propagation of radiation through a disordered waveguide with a complex dielectric constant $\epsilon$, and show that dual systems, which differ only in the sign of the imaginary part of $\epsilon$, have the same localization length. Paradoxically, absorption and stimulated emission of radiation suppress the transmittance of the waveguide in the same way.Comment: Added a reference to the paper by Z.Q. Zhang, Phys.Rev.B. 52, 7960 (1995

The Disk Substructures at High Angular Resolution Project (DSHARP). II. Characteristics of Annular Substructures

The Disk Substructures at High Angular Resolution Project (DSHARP) used ALMA to map the 1.25 mm continuum of protoplanetary disks at a spatial resolution of ~5 au. We present a systematic analysis of annular substructures in the 18 single-disk systems targeted in this survey. No dominant architecture emerges from this sample; instead, remarkably diverse morphologies are observed. Annular substructures can occur at virtually any radius where millimeter continuum emission is detected and range in widths from a few astronomical units to tens of astronomical units. Intensity ratios between gaps and adjacent rings range from near-unity to just a few percent. In a minority of cases, annular substructures coexist with other types of substructures, including spiral arms (3/18) and crescent-like azimuthal asymmetries (2/18). No clear trend is observed between the positions of the substructures and stellar host properties. In particular, the absence of an obvious association with stellar host luminosity (and hence the disk thermal structure) suggests that substructures do not occur preferentially near major molecular snowlines. Annular substructures like those observed in DSHARP have long been hypothesized to be due to planet–disk interactions. A few disks exhibit characteristics particularly suggestive of this scenario, including substructures in possible mean-motion resonance and double gap features reminiscent of hydrodynamical simulations of multiple gaps opened by a planet in a low-viscosity disk

Learning Scheduling Algorithms for Data Processing Clusters

Efficiently scheduling data processing jobs on distributed compute clusters requires complex algorithms. Current systems, however, use simple generalized heuristics and ignore workload characteristics, since developing and tuning a scheduling policy for each workload is infeasible. In this paper, we show that modern machine learning techniques can generate highly-efficient policies automatically. Decima uses reinforcement learning (RL) and neural networks to learn workload-specific scheduling algorithms without any human instruction beyond a high-level objective such as minimizing average job completion time. Off-the-shelf RL techniques, however, cannot handle the complexity and scale of the scheduling problem. To build Decima, we had to develop new representations for jobs' dependency graphs, design scalable RL models, and invent RL training methods for dealing with continuous stochastic job arrivals. Our prototype integration with Spark on a 25-node cluster shows that Decima improves the average job completion time over hand-tuned scheduling heuristics by at least 21%, achieving up to 2x improvement during periods of high cluster load