ABSTRACT
BACKGROUND AND PURPOSE
Pain information from the face enters the pons via the trigeminal nerve before creating an anatomical “elbow” that turns caudally into the spinal trigeminal tract ...(SpTV). Visualization of the descending tract of the trigeminal nerve as it begins its descent from the nerve root entry zone (NREZ) in the pons would improve the accuracy of current procedures aimed at altering or lesioning the trigeminal nerve within the brainstem. The focus of this study was to develop a standardized protocol using diffusion tensor imaging (DTI) and deterministic tractography methods to image the SpTV. There are currently no standard techniques used to visualize the trigeminal nerve using DTI.
METHODS
DTI and tractography were performed on 20 patients: 17 with trigeminal neuralgia (TN), 1 with hemifacial spasm, 1 with a facial nerve tumor, and 1 with an arteriovenous malformation. A standardized protocol was developed using regions of interest (ROIs) located at the SpTV, as determined by a brainstem atlas, and the NREZ.
RESULTS
Using our standardized protocol, the descending tract of the trigeminal nerve was successfully visualized in all 20 patients. Trigeminal fibers entered the pons at the NREZ and descended through the SpTV. The accuracy of the visualized tract was confirmed through coregistration with a stereotactic atlas and anatomical scan.
CONCLUSION
A successful, robust DTI imaging and postprocessing protocol of the SpTV contributes to our understanding of its anatomical distribution within the brainstem and is a potentially new neurosurgical planning tool.
Waiting for the revolution is a volume of essays examining the diverse currents of British left-wing politics from 1956 to the present day. The book is designed to complement the previous volume, ...Against the grain: The far left in Britain from 1956, bringing together young and established academics and writers to discuss the realignments and fissures that maintain leftist politics into the twenty-first century. The two books endeavour to historicise the British left, detailing but also seeking to understand the diverse currents that comprise 'the far left'. Their objective is less to intervene in ongoing issues relevant to the left and politics more generally, than to uncover and explore the traditions and issues that have preoccupied leftist groups, activists and struggles. To this end, the book will appeal to scholars and anyone interested in British politics.
Disaster triage training for emergency medical service (EMS) providers is not standardized. Simulation training is costly and time-consuming. In contrast, educational video games enable low-cost and ...more time-efficient standardized training. We hypothesized that players of the video game "60 Seconds to Survival" (60S) would have greater improvements in disaster triage accuracy compared to control subjects who did not play 60S.
Participants recorded their demographics and highest EMS training level and were randomized to play 60S (intervention) or serve as controls. At baseline, all participants completed a live school-shooting simulation in which manikins and standardized patients depicted 10 adult and pediatric victims. The intervention group then played 60S at least three times over the course of 13 weeks (time 2). Players triaged 12 patients in three scenarios (school shooting, house fire, tornado), and received in-game performance feedback. At time 2, the same live simulation was conducted for all participants. Controls had no disaster training during the study. The main outcome was improvement in triage accuracy in live simulations from baseline to time 2. Physicians and EMS providers predetermined expected triage level (RED/YELLOW/GREEN/BLACK) via modified Delphi method.
There were 26 participants in the intervention group and 21 in the control group. There was no difference in gender, level of training, or years of EMS experience (median 5.5 years intervention, 3.5 years control, p = 0.49) between the groups. At baseline, both groups demonstrated median triage accuracy of 80 percent (IQR 70-90 percent, p = 0.457). At time 2, the intervention group had a significant improvement from baseline (median accuracy = 90 percent IQR: 80-90 percent, p = 0.005), while the control group did not (median accuracy = 80 percent IQR:80-95, p = 0.174). However, the mean improvement from baseline was not significant between the two groups (difference = 6.5, p = 0.335).
The intervention demonstrated a significant improvement in accuracy from baseline to time 2 while the control did not. However, there was no significant difference in the improvement between the intervention and control groups. These results may be due to small sample size. Future directions include assessment of the game's effect on triage accuracy with a larger, multisite site cohort and iterative development to improve 60S.
Current treatment strategies in patients with trigeminal neuralgia (TN) include trials of medical therapy and surgical intervention, when necessary. In some patients, pain is not adequately managed ...with these existing strategies.
To present a novel technique, ventral pontine trigeminal tractotomy via retrosigmoid craniectomy, as an adjunct treatment in TN when there is no significant neurovascular compression.
We present a nonrandomized retrospective comparison between 50 patients who lacked clear or impressive arterial neurovascular compression of the trigeminal nerve as judged by preoperative magnetic resonance imaging and intraoperative observations. These patients had intractable TN unresponsive to previous treatment. Trigeminal tractotomy was performed either alone or in conjunction with microvascular decompression. Stereotactic neuronavigation was used during surgery to localize the descending tract via a ventral pontine approach for descending tractotomy.
Follow-up was a mean of 44 months. At first follow-up, 80% of patients experienced complete relief of their pain, and 18% had partial relief. At the most recent follow-up, 74% of patients were considered a successful outcome. Only 1 (2%) patient had no relief after trigeminal tractotomy. Of those with multiple sclerosis-related TN, 87.5% experienced successful relief of pain at their latest follow-up.
While patient selection is a significant challenge, this procedure represents an option for patients with TN who have absent or equivocal neurovascular compression, multiple sclerosis-related TN, or recurrent TN.
Superconducting qubits are an attractive platform for quantum computing since they have demonstrated high-fidelity quantum gates and extensibility to modest system sizes. Nonetheless, an outstanding ...challenge is stabilizing their energy-relaxation times, which can fluctuate unpredictably in frequency and time. Here, we use qubits as spectral and temporal probes of individual two-level-system defects to provide direct evidence that they are responsible for the largest fluctuations. This research lays the foundation for stabilizing qubit performance through calibration, design, and fabrication.
Signaling abnormalities in immune responses in the small intestine can trigger chronic type 2 inflammation involving interaction of multiple immune cell types. To systematically characterize this ...response, we analyzed 58,067 immune cells from the mouse small intestine by single-cell RNA sequencing (scRNA-seq) at steady state and after induction of a type 2 inflammatory reaction to ovalbumin (OVA). Computational analysis revealed broad shifts in both cell-type composition and cell programs in response to the inflammation, especially in group 2 innate lymphoid cells (ILC2s). Inflammation induced the expression of exon 5 of Calca, which encodes the alpha-calcitonin gene-related peptide (α-CGRP), in intestinal KLRG1+ ILC2s. α-CGRP antagonized KLRG1+ ILC2s proliferation but promoted IL-5 expression. Genetic perturbation of α-CGRP increased the proportion of intestinal KLRG1+ ILC2s. Our work highlights a model where α-CGRP-mediated neuronal signaling is critical for suppressing ILC2 expansion and maintaining homeostasis of the type 2 immune machinery.
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•scRNA-seq reveals intestinal immune cell programs in allergic inflammation•Intestinal KLRG1+ ILC2s express α-CGRP and its receptors•α-CGRP regulates type 2 cytokine production of KLRG1+ ILC2s•α-CGRP maintains KLRG1+ ILC2 homeostasis and the type 2 immune machinery
Allergic inflammation involves the interaction of multiple immune cell types, as well as their crosstalk with other physiological systems, such as neurons. By establishing intestinal immune cell atlas at different states, Xu et al. identify that neuropeptide α-CGRP modulates group 2 innate lymphoid cell responses and the allergic reaction.
Implementation of an error-corrected quantum computer is believed to require a quantum processor with a million or more physical qubits, and, in order to run such a processor, a quantum control ...system of similar scale will be required. Such a controller will need to be integrated within the cryogenic system and in close proximity with the quantum processor in order to make such a system practical. Here, we present a prototype cryogenic CMOS quantum controller designed in a 28-nm bulk CMOS process and optimized to implement a 16-word (4-bit) XY gate instruction set for controlling transmon qubits. After introducing the transmon qubit, including a discussion of how it is controlled, design considerations are discussed, with an emphasis on error rates and scalability. The circuit design is then discussed. Cryogenic performance of the underlying technology is presented, and the results of several quantum control experiments carried out using the integrated controller are described. This article ends with a comparison to the state of the art and a discussion of further research to be carried out. It has been shown that the quantum control IC achieves promising performance while dissipating less than 2 mW of total ac and dc power and requiring a digital data stream of less than 500 Mb/s.
Scalable quantum computing can become a reality with error correction, provided that coherent qubits can be constructed in large arrays1,2. The key premise is that physical errors can remain both ...small and sufficiently uncorrelated as devices scale, so that logical error rates can be exponentially suppressed. However, impacts from cosmic rays and latent radioactivity violate these assumptions. An impinging particle can ionize the substrate and induce a burst of quasiparticles that destroys qubit coherence throughout the device. High-energy radiation has been identified as a source of error in pilot superconducting quantum devices3–5, but the effect on large-scale algorithms and error correction remains an open question. Elucidating the physics involved requires operating large numbers of qubits at the same rapid timescales necessary for error correction. Here, we use space- and time-resolved measurements of a large-scale quantum processor to identify bursts of quasiparticles produced by high-energy rays. We track the events from their initial localized impact as they spread, simultaneously and severely limiting the energy coherence of all qubits and causing chip-wide failure. Our results provide direct insights into the impact of these damaging error bursts and highlight the necessity of mitigation to enable quantum computing to scale.Cosmic rays flying through superconducting quantum devices create bursts of excitations that destroy qubit coherence. Rapid, spatially resolved measurements of qubit error rates make it possible to observe the evolution of the bursts across a chip.
Current judging of race walking in international competitions relies on subjective human observation to detect illegal gait, which naturally has inherent problems. Incorrect judging decisions may ...devastate an athlete and possibly discredit the international governing body. The aim of this study was to determine whether an inertial sensor could improve accuracy, monitor every step the athlete makes in training and/or competition. Seven nationally competitive race walkers performed a series of legal, illegal and self-selected pace races. During testing, athletes wore a single inertial sensor (100 Hz) placed at S1 of the vertebra and were simultaneously filmed using a high-speed camera (125 Hz). Of the 80 steps analyzed the high-speed camera identified 57 as illegal, the inertial sensor misidentified four of these measures (all four missed illegal steps had 0.008 s of loss of ground contact) which is considerably less than the best possible human observation of 0.06 s. Inertial sensor comparison to the camera found the typical error of estimate was 0.02 s (95% confidence limits 0.01-0.02), with a bias of 0.02 (±0.01). An inertial sensor can thus objectively improve the accuracy in detecting illegal steps (loss of ground contact) and, along with the ability to monitor every step of the athlete, could be a valuable tool to assist judges during race walk events.
The promise of quantum computers is that certain computational tasks might be executed exponentially faster on a quantum processor than on a classical processor
. A fundamental challenge is to build ...a high-fidelity processor capable of running quantum algorithms in an exponentially large computational space. Here we report the use of a processor with programmable superconducting qubits
to create quantum states on 53 qubits, corresponding to a computational state-space of dimension 2
(about 10
). Measurements from repeated experiments sample the resulting probability distribution, which we verify using classical simulations. Our Sycamore processor takes about 200 seconds to sample one instance of a quantum circuit a million times-our benchmarks currently indicate that the equivalent task for a state-of-the-art classical supercomputer would take approximately 10,000 years. This dramatic increase in speed compared to all known classical algorithms is an experimental realization of quantum supremacy
for this specific computational task, heralding a much-anticipated computing paradigm.
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