Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Sensory fusion in the hoverfly righting reflex

We study how falling hoverflies use sensory cues to trigger appropriate roll righting behavior. Before being released in a free fall, flies were placed upside-down with their legs contacting the substrate. The prior leg proprioceptive information about their initial orientation sufficed for the flies to right themselves properly. However, flies also use visual and antennal cues to recover faster and disambiguate sensory conflicts. Surprisingly, in one of the experimental conditions tested, hoverflies flew upside-down while still actively flapping their wings. In all the other conditions, flies were able to right themselves using two roll dynamics: fast ([Formula: see text]50ms) and slow ([Formula: see text]110ms) in the presence of consistent and conflicting cues, respectively. These findings suggest that a nonlinear sensory integration of the three types of sensory cues occurred. A ring attractor model was developed and discussed to account for this cue integration process.

Possible biased virulence attenuation in the Senegal strain of Ehrlichia ruminantium by ntrX gene conversion from an inverted segmental duplication

Ehrlichia ruminantium is a tick-borne intracellular pathogen of ruminants that causes heartwater, a disease present in Sub-saharan Africa, islands in the Indian Ocean and the Caribbean, inducing significant economic losses. At present, three avirulent strains of E. ruminantium (Gardel, Welgevonden and Senegal isolates) have been produced by a process of serial passaging in mammalian cells in vitro, but unfortunately their use as vaccines do not offer a large range of protection against other strains, possibly due to the genetic diversity present within the species. So far no genetic basis for virulence attenuation has been identified in any E. ruminantium strain that could offer targets to facilitate vaccine production. Virulence attenuated Senegal strains have been produced twice independently, and require many fewer passages to attenuate than the other strains. We compared the genomes of a virulent and attenuated Senegal strain and identified a likely attenuator gene, ntrX, a global transcription regulator and member of a two-component system that is linked to environmental sensing. This gene has an inverted partial duplicate close to the parental gene that shows evidence of gene conversion in different E. ruminantium strains. The pseudogenisation of the gene in the avirulent Senegal strain occurred by gene conversion from the duplicate to the parent, transferring a 4 bp deletion which is unique to the Senegal strain partial duplicate amongst the wild isolates. We confirmed that the ntrX gene is not expressed in the avirulent Senegal strain by RT-PCR. The inverted duplicate structure combined with the 4 bp deletion in the Senegal strain can explain both the attenuation and the faster speed of attenuation in the Senegal strain relative to other strains of E. ruminantium. Our results identify nrtX as a promising target for the generation of attenuated strains of E. ruminantium by random or directed mutagenesis that could be used for vaccine production.

Aortic and vascular involvement in Loeys-Dietz Syndrome. Results from the REPAG registry (Spanish network of genetic aortic diseases)

Background

LDS is a rare disease due to genetic variants in the TGFB pathway. Limited information is available regarding the overall aortic and vascular outcome of these patients

Purpose

To evaluate aortic and vascular complications of patients with mutations in the TGFB pathway.

Methods

Retrospective longitudinal study including patients with (likely) pathogenic (LP/P) variants in the TGFbeta pathway from 10 tertiary centers. Clinical and imaging data were reviewed and data on aortic and vascular outcome included.

Results

A total of 163 patients were included (47.9% women, 38.6% index cases), mean age at first evaluation 32.3±20.4 years, 27.0% with age <16 years. 70 TGFBR1, 43 TGFBR2, 29 SMAD3, 9 TGFB2 and 12 TGFB3 (Table1)

During a mean follow-up of 4.7±3.7 years, 54 (33.1%) patients had at least 1 aortic surgery (max 6). Mean age at first aortic surgery was 37.2±16.8 years (Range 1.2–72.9). First surgery was elective in 42 (77.8%), and included aortic root or ascending aorta in 40 (95.2%) and isolated descending aorta in 2 (4.8%). Emergent surgery included aortic root or ascending aorta in 11 (92.7%). Ascending aorta-root diameter previous to elective surgery was 48.9±4.9mm (range 41–65). 7 patients died during follow-up (2 intracranial bleeding, 1 SD, 2 aortic ruptures, 1post aortic surgery, 1 non-CV). Furthermore, 19 acute aortic syndromes (AAS) were reported (17 dissections, 2 haematomas) in 18 patients, 10 type A (52.6%). Mean age at first AAS was 42.3±11.1 years (min 19.7 years to 62.9 years)

Median survival free of intervention, dissection or death was 57.1 years, being worst for men than women (44.7 yrs vs 69.1 years, p<0.001) (Figure 1), these gender-difference only remained significant in the TGFBR1 and SMAD3 groups (p=0.005 and p=0.008) Regarding aortic branch and intracranial aneurysms, a total of 383 imaging studies of aortic branches and 223 cranial imaging studies were performed during the clinical follow-up. 21 cranial aneurysms and 73 aortic branch aneurisms were reported. 14 (11.5%) patients suffered 19 aneurysms-related events (3 dissections, 3 ruptures, 13 interventions).

Conclusions

In patients with Loeys-Dietz Syndrome, there's a high prevalence of aortic surgeries and acute aortic events, with high numbers of peripheral and intracranial aneurysms. A worst prognosis in men than in women is observed in TGFBR1 and SMAD3 variants. Thus, specialized clinical and imaging follow-up is crucial in the management of these patients

Funding Acknowledgement

Type of funding sources: None.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Long-term effect of obstructive sleep apnea and CPAP treatment on blood pressure control in patients after acute coronary syndrome

Funding Acknowledgements

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Instituto de Salud Carlos III (ISCIII) (PI10/02763, PI10/02745, PI18/00449, PI19/00907), co-funded by FEDER “Una manera de hacer Europa”, SEPAR, Catalonian Cardiology Society, ResMed Ltd. (Australia), EsteveTeijin (Spain), Oxigen Salud (Spain), Associació Lleidatana de Respiratori (ALLER), CIBERES. MS received financial support from a "Ramón y Cajal" grant (RYC2019-027831-I) from the“Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación” co-funded by the European Social Fund (ESF)/“Investing in your future”. AZ held the predoctoral fellowship “Ajuts 2021 de Promoció de la Recerca en Salut-9ª edició” from IRBLleida/Diputació de Lleida. JdB acknowledges receiving financial support from ISCIII (Miguel Servet 2019: CP19/00108), co-funded by the European Social Fund (ESF), “Investing in your future”.

Rationale

Obstructive sleep apnea (OSA) is prevalent in acute coronary syndrome (ACS) patients and is a cause of secondary hypertension.

Objectives

To evaluate the long-term effects of OSA and CPAP treatment on blood pressure (BP) control in patients discharged after an ACS.

Methods

Post hoc analysis of the ISAACC study included 1803 patients admitted for ACS (NCT01335087). Patients with OSA (apnea-hypopnea index ≥15 events/h) were randomly assigned to receive either CPAP or/and usual care and followed up for one to 5 years. Office BP was determined at each visit.

Measurements and Main Results

We included 596 patients without OSA, 605 patients in the CPAP group, and 602 patients in the usual care group. 52% of the patients had a diagnosis of hypertension at baseline. Median age and body mass index were 59 [52.0;67.0] years and 28.2 [25.6;31.2] kg/m2, respectively. After a median [25th;75th percentile] follow-up of 41.2 [18.3;59.6] months, BP changes were similar between OSA and non-OSA groups. However, we observed an increase in BP in the third tertile of the AHI (AHI>40 events/h) with a maximum difference in mean BP of +3.3 mmHg at 30 months. OSA patients with good CPAP adherence (≥4 hours/night) reduced mean BP after 18 months compared to non-OSA and poor CPAP adherence patients, maximum mean difference (95% CI) of -4.7 (-6.7,-2.7) mmHg. In patients with severe OSA we observed a maximum mean difference of -7.1 (-10.3,-3.8) mmHg.

Conclusions

In patients discharged after an ACS, severe OSA is associated with a long-term increase in BP, which is reduced by good CPAP adherence.

Order-of-magnitude increase in laser-target coupling at near-relativistic intensities using compound parabolic concentrators

Achieving a high conversion efficiency into relativistic electrons is central to short-pulse laser application and fundamentally relies on creating interaction regions with intensities ≫10^{18}W/cm^{2}. Small focal length optics are typically employed to achieve this goal; however, this solution is impractical for large kJ-class systems that are constrained by facility geometry, debris concerns, and component costs. We fielded target-mounted compound parabolic concentrators to overcome these limitations and achieved nearly an order-of-magnitude increase to the conversion efficiency and more than tripled electron temperature compared to flat targets. Particle-in-cell simulations demonstrate that plasma confinement within the cone and formation of turbulent laser fields that develop from cone wall reflections are responsible for the improved laser-to-target coupling. These passive target components can be used to improve the coupling efficiency for all high-intensity short-pulse laser applications, particularly at large facilities with long focal length optics.

Social and professional consequences of COVID-19 lockdown in patients with multiple sclerosis from 2 very different populations

Objective

Method

Results

Conclusions

Simulation of Large Scale Neural Models With Event-Driven Connectivity Generation

Accurate simulations of brain structures is a major problem in neuroscience. Many works are dedicated to design better models or to develop more efficient simulation schemes. In this paper, we propose a hybrid simulation scheme that combines time-stepping second-order integration of Hodgkin-Huxley (HH) type neurons with event-driven updating of the synaptic currents. As the HH model is a continuous model, there is no explicit spike events. Thus, in order to preserve the accuracy of the integration method, a spike detection algorithm is developed that accurately determines spike times. This approach allows us to regenerate the outgoing connections at each event, thereby avoiding the storage of the connectivity. Consequently, memory consumption is significantly reduced while preserving execution time and accuracy of the simulations, especially the spike times of detailed point neuron models. The efficiency of the method, implemented in the SiReNe software¹, is demonstrated by the simulation of a striatum model which consists of more than 10⁶ neurons and 10⁸ synapses (each neuron has a fan-out of 504 post-synaptic neurons), under normal and Parkinson's conditions.

Time-Resolved Fuel Density Profiles of the Stagnation Phase of Indirect-Drive Inertial Confinement Implosions

The implosion efficiency in inertial confinement fusion depends on the degree of stagnated fuel compression, density uniformity, sphericity, and minimum residual kinetic energy achieved. Compton scattering-mediated 50-200 keV x-ray radiographs of indirect-drive cryogenic implosions at the National Ignition Facility capture the dynamic evolution of the fuel as it goes through peak compression, revealing low-mode 3D nonuniformities and thicker fuel with lower peak density than simulated. By differencing two radiographs taken at different times during the same implosion, we also measure the residual kinetic energy not transferred to the hot spot and quantify its impact on the implosion performance.

Targeted rapid testing for SARS-CoV-2 in the emergency department is associated with large reductions in uninfected patient exposure time

Opportunity exists to decrease healthcare-related exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), preserve infection control resources, and increase care capacity by reducing the time to diagnosis of coronavirus disease 2019 (COVID-19). A retrospective cohort analysis was undertaken to measure the effect of targeted rapid molecular testing for SARS-CoV-2 on these outcomes. In comparison with standard platform testing, rapid testing was associated with a 65.6% reduction (12.6 h) in the median time to removal from the isolation cohort for patients with negative diagnostic results. This translated to an increase in COVID-19 treatment capacity of 3028 bed-hours and 7500 fewer patient interactions that required the use of personal protective equipment per week.

Automatic tracking of free-flying insects using a cable-driven robot

Flying insects have evolved to develop efficient strategies to navigate in natural environments. Yet, studying them experimentally is difficult because of their small size and high speed of motion. Consequently, previous studies were limited to tethered flights, hovering flights, or restricted flights within confined laboratory chambers. Here, we report the development of a cable-driven parallel robot, named lab-on-cables, for tracking and interacting with a free-flying insect. In this approach, cameras are mounted on cables, so as to move automatically with the insect. We designed a reactive controller that minimizes the online tracking error between the position of the flying insect, provided by an embedded stereo-vision system, and the position of the moving lab, computed from the cable lengths. We validated the lab-on-cables with Agrotis ipsilon moths (ca. 2 centimeters long) flying freely up to 3 meters per second. We further demonstrated, using prerecorded trajectories, the possibility to track other insects such as fruit flies or mosquitoes. The lab-on-cables is relevant to free-flight studies and may be used in combination with stimulus delivery to assess sensory modulation of flight behavior (e.g., pheromone-controlled anemotaxis in moths).

1079 Is PTSD In Young Women Associated With Rem Sleep Abnormalities?

Introduction

The increase in violence against young women has a high impact on the prevalence of Posttraumatic stress disorder (PTSD). The lifetime prevalence of PTSD is twice as high in women. However, most studies assessing sleep disturbances in PTSD were conducted predominantly in male samples and combat veterans. Objective: To analyze the sleep of young women with and without PTSD. Hypothesis: Women with PTSD have worse sleep quality, higher arousability, and higher muscle activity during REM sleep.

Methods

Case-controlled study with young women. Seventy-four women who suffered sexual assault and developed PTSD (DSM-5); and 64 women from the community without PTSD. Women were recruited from the PTSD outpatient clinic (Universidade Federal de São Paulo, Brazil).Clinician-Administered Posttraumatic Stress Scale (CAPS 5), Beck Depression and Anxiety Inventories (BDI) (BAI), full in-lab Polysomnography (PSG), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Índex (PSQI), Fatigue Impact Scale (FIS), and Insomnia Severity Índex (ISI) were applied to all participants. Analysis of variance, regression models, and general linear modeling were used.

Results

Patients mean age was 28 vs 24 for the control group (p=0.004). CAPS mean score in PTSD-group was 42.5±9.1. BDI, BAI, FIS, PSQI, ISI scores were worse in PTSD-group (p<0.05, all). Pittsburgh Sleep Quality Index (PSQI) score was significantly associated with CAPS 5 independently of depression, fatigue, and sleep fragmentation.

The PTSD women had lower total sleep time (p= 0.01) and lower REM sleep percentage (p=0.04). However, the control group had higher arousal index (p=.0.01) and had higher muscle activity during REM sleep (p=0.03) than PTSD.

Conclusion

Women with PTSD had significantly worse score in PSQI, FIS, and ISI. PSQI score was associated with PTSD severity. However, when PSG results are concerned, we found higher sleep fragmentation in the control group. We speculate that women with PTSD may have felt safer and taken care of in the lab, which might explain the difference between objective and subjective measures of sleep quality in PTSD.

Support

Acknowledgments: FAPESP: Fundação de Apoio à pesquisa de São Paulo, AFIP: Associação Incentivo a Pesquisa

Production of relativistic electrons at subrelativistic laser intensities

Relativistic electron temperatures were measured from kilojoule, subrelativistic laser-plasma interactions. Experiments show an order of magnitude higher temperatures than expected from a ponderomotive scaling, where temperatures of up to 2.2 MeV were generated using an intensity of 1×10^{18}W/cm^{2}. Two-dimensional particle-in-cell simulations suggest that electrons gain superponderomotive energies by stochastic acceleration as they sample a large area of rapidly changing laser phase. We demonstrate that such high temperatures are possible from subrelativistic intensities by using lasers with long pulse durations and large spatial scales.

Adaptive quantization of local field potentials for wireless implants in freely moving animals: an open-source neural recording device

OBJECTIVE

Modern neuroscience research requires electrophysiological recording of local field potentials (LFPs) in moving animals. Wireless transmission has the advantage of removing the wires between the animal and the recording equipment but is hampered by the large number of data to be sent at a relatively high rate.

APPROACH

To reduce transmission bandwidth, we propose an encoder/decoder scheme based on adaptive non-uniform quantization. Our algorithm uses the current transmitted codeword to adapt the quantization intervals to changing statistics in LFP signals. It is thus backward adaptive and does not require the sending of side information. The computational complexity is low and similar at the encoder and decoder sides. These features allow for real-time signal recovery and facilitate hardware implementation with low-cost commercial microcontrollers.

MAIN RESULTS

As proof-of-concept, we developed an open-source neural recording device called NeRD. The NeRD prototype digitally transmits eight channels encoded at 10 kHz with 2 bits per sample. It occupies a volume of 2  ×  2  ×  2 cm³ and weighs 8 g with a small battery allowing for 2 h 40 min of autonomy. The power dissipation is 59.4 mW for a communication range of 8 m and transmission losses below 0.1%. The small weight and low power consumption offer the possibility of mounting the entire device on the head of a rodent without resorting to a separate head-stage and battery backpack. The NeRD prototype is validated in recording LFPs in freely moving rats at 2 bits per sample while maintaining an acceptable signal-to-noise ratio (>30 dB) over a range of noisy channels.

SIGNIFICANCE

Adaptive quantization in neural implants allows for lower transmission bandwidths while retaining high signal fidelity and preserving fundamental frequencies in LFPs.

Fast Measurements with MOX Sensors: A Least-Squares Approach to Blind Deconvolution

Metal oxide (MOX) sensors are widely used for chemical sensing due to their low cost, miniaturization, low power consumption and durability. Yet, getting instantaneous measurements of fluctuating gas concentration in turbulent plumes is not possible due to their slow response time. In this paper, we show that the slow response of MOX sensors can be compensated by deconvolution, provided that an invertible, parametrized, sensor model is available. We consider a nonlinear, first-order dynamic model that is mathematically tractable for MOX identification and deconvolution. By transforming the sensor signal in the log-domain, the system becomes linear in the parameters and these can be estimated by the least-squares techniques. Moreover, we use the MOX diversity in a sensor array to avoid training with a supervised signal. The information provided by two (or more) sensors, exposed to the same flow but responding with different dynamics, is exploited to recover the ground truth signal (gas input). This approach is known as blind deconvolution. We demonstrate its efficiency on MOX sensors recorded in turbulent plumes. The reconstructed signal is similar to the one obtained with a fast photo-ionization detector (PID). The technique is thus relevant to track a fast-changing gas concentration with MOX sensors, resulting in a compensated response time comparable to that of a PID.

Clinical and epidemiological features of myasthenia gravis in Chilean population

OBJECTIVE

To provide an estimated prevalence and describe the clinical features of myasthenia gravis (MG) in Chile.

METHOD

We carried out (i) a prevalence study of MG using the capture-recapture method and the hospital register of pyridostigmine prescription in South-East Santiago (ii) a nationwide survey of MG patients.

RESULTS

Prevalence in adults in South-East Santiago was estimated to be 8.36/100 000 inhabitants (CI: 95%, 7.98-8.80). From the nationwide survey, 405 questionnaires were analysed, there was a female/male ratio of 2.2:1. The mean age of onset of symptoms was 38.7 years (range 1-89). The onset was ocular in 46.4%, oculobulbar in 11.6%, bulbar in 8.9%, limbs in 11.6% and generalized in 21.4%. Of the 13.3% of patients who had had a diagnosis of thymoma, only four of these patients were >60 years old at onset. Thymomas were commoner in patients living in mining counties. Patients ≥60 years old at onset of MG formed 19.5% of the sample, female/male ratio 0.97:1. Associated autoimmune diseases were reported in 14% of patients and in family members of 31.8% of patients. A total of 78 patients had to change work due to MG and 68 needed help in carrying out daily activities.

CONCLUSIONS

This study reduces the gap in information about MG in South America. The prevalence of MG in Chile is within the range described worldwide. We did not see an increase in male frequency in the older age of onset group and thymoma was more frequent in the fifth and sixth decades.

Effects of ibudilast on oxycodone-induced analgesia and subjective effects in opioid-dependent volunteers

Opioid-induced glial activation is hypothesized to contribute to the development of tolerance to opioid-induced analgesia. This inpatient, double-blind, placebo-controlled, within-subject and between-groups pilot study investigated the dose-dependent effects of ibudilast, a glial cell modulator, on oxycodone-induced analgesia. Opioid-dependent volunteers were maintained on morphine (30mg, PO, QID) for two weeks and received placebo ibudilast (0mg, PO, BID) during the 1st week (days 1-7). On day 8, participants (N=10/group) were randomized to receive ibudilast (20 or 40mg, PO, BID) or placebo for the remainder of the study. On days 4 (week 1) and 11 (week 2), the analgesic, subjective, and physiological effects of oxycodone (0, 25, 50mg/70kg, PO) were determined. Analgesia was measured using the cold pressor test; participants immersed their hand in cold water (4°C) and pain threshold and pain tolerability were recorded. Oxycodone decreased pain threshold and tolerability in all groups during week 1. During week 2, the placebo group exhibited a blunted analgesic response to oxycodone for pain threshold and subjective pain ratings, whereas the 40mg BID ibudilast group exhibited greater analgesia as measured by subjective pain ratings (p≤0.05). Oxycodone also increased subjective drug effect ratings associated with abuse liability in all groups during week 1 (p≤0.05); ibudilast did not consistently affect these ratings. These findings suggest that ibudilast may enhance opioid-induced analgesia. Investigating higher ibudilast doses may establish the utility of pharmacological modulation of glial activity to maximize the clinical use of opioids.