Inertial confinement fusion implosions designed to have minimal fluid motion at peak compression often show significant linear flows in the laboratory, attributable per simulations to percent-level ...imbalances in the laser drive illumination symmetry. We present experimental results which intentionally varied the mode 1 drive imbalance by up to 4% to test hydrodynamic predictions of flows and the resultant imploded core asymmetries and performance, as measured by a combination of DT neutron spectroscopy and high-resolution x-ray core imaging. Neutron yields decrease by up to 50%, and anisotropic neutron Doppler broadening increases by 20%, in agreement with simulations. Furthermore, a tracer jet from the capsule fill-tube perturbation that is entrained by the hot-spot flow confirms the average flow speeds deduced from neutron spectroscopy.
Objective
To report on the effectiveness of a standardised core Maternity Waiting Home (MWH) model to increase facility deliveries among women living >10 km from a health facility.
Design
...Quasi‐experimental design with partial randomisation at the cluster level.
Setting
Seven rural districts in Zambia.
Population
Women delivering at 40 health facilities between June 2016 and August 2018.
Methods
Twenty intervention and 20 comparison sites were used to test whether MWHs increased facility delivery for women living in rural Zambia. Difference‐in‐differences (DID) methodology was used to examine the effectiveness of the core MWH model on our identified outcomes.
Main outcome measures
Differences in the change from baseline to study period in the percentage of women living >10 km from a health facility who: (1) delivered at the health facility, (2) attended a postnatal care (PNC) visit and (3) were referred to a higher‐level health facility between intervention and comparison group.
Results
We detected a significant difference in the percentage of deliveries at intervention facilities with the core MWH model for all women living >10 km away (DID 4.2%, 95% CI 0.6–7.6, P = 0.03), adolescent women (<18 years) living >10 km away (DID 18.1%, 95% CI 6.3–29.8, P = 0.002) and primigravida women living >10 km away (DID 9.3%, 95% CI 2.4–16.4, P = 0.01) and for women attending the first PNC visit (DID 17.8%, 95% CI 7.7–28, P < 0.001).
Conclusion
The core MWH model was successful in increasing rates of facility delivery for women living >10 km from a healthcare facility, including adolescent women and primigravidas and attendance at the first PNC visit.
Tweetable
A core MWH model increased facility delivery for women living >10 km from a health facility including adolescents and primigravidas in Zambia.
Tweetable
A core MWH model increased facility delivery for women living >10 km from a health facility including adolescents and primigravidas in Zambia.
We present the first x-ray scattering measurements of the state of compression and heating in laser irradiated solid beryllium. The scattered spectra at two different angles show Compton and plasmon ...features indicating a dense Fermi-degenerate plasma state with a Fermi energy above 30 eV and with temperatures in the range of 10-15 eV. These measurements indicate compression by a factor of 3 in agreement with Hugoniot data and detailed radiation-hydrodynamic modeling.
At the National Ignition Facility, inertial confinement fusion experiments aim to burn and ignite a hydrogen plasma to generate a net source of energy through the fusion of deuterium and tritium ...ions. The energy deposited by α-particles released from the deuterium–tritium fusion reaction plays the central role in heating the fuel to achieve a sustained thermonuclear burn. In the hydrodynamic picture, α-heating increases the temperature of the plasma, leading to increased reactivity because the mean ion kinetic energy increases. Therefore, the ion temperature is related to the mean ion kinetic energy. Here we use the moments of the neutron spectrum to study the relationship between the ion temperature (measured by the variance in the neutron kinetic energy spectrum) and the ion mean kinetic energy (measured by the shift in the mean neutron energy). We observe a departure from the relationship expected for plasmas where the ion relative kinetic energy distribution is Maxwell–Boltzmann, when the plasma begins to burn. Understanding the cause of this departure from hydrodynamic behaviour could be important for achieving robust and reproducible ignition.Inertial confinement fusion experiments reveal a departure from the expected hydrodynamic behaviour of a plasma when the fusion reactions become the primary source of plasma heating.
Ignition implosions on the National Ignition Facility J. D. Lindl et al., Phys. Plasmas 11, 339 (2004) are underway with the goal of compressing deuterium-tritium fuel to a sufficiently high areal ...density (ρR) to sustain a self-propagating burn wave required for fusion power gain greater than unity. These implosions are driven with a very carefully tailored sequence of four shock waves that must be timed to very high precision to keep the fuel entropy and adiabat low and ρR high. The first series of precision tuning experiments on the National Ignition Facility, which use optical diagnostics to directly measure the strength and timing of all four shocks inside a hohlraum-driven, cryogenic liquid-deuterium-filled capsule interior have now been performed. The results of these experiments are presented demonstrating a significant decrease in adiabat over previously untuned implosions. The impact of the improved shock timing is confirmed in related deuterium-tritium layered capsule implosions, which show the highest fuel compression (ρR~1.0 g/cm(2)) measured to date, exceeding the previous record V. Goncharov et al., Phys. Rev. Lett. 104, 165001 (2010) by more than a factor of 3. The experiments also clearly reveal an issue with the 4th shock velocity, which is observed to be 20% slower than predictions from numerical simulation.
The mechanism of substrate translocation through the ribosome is central to the rapid and faithful translation of mRNA into proteins. The rate-limiting step in translocation is an unlocking process ...that includes the formation of an "unlocked" intermediate state, which requires the convergence of large-scale conformational events within the ribosome including tRNA hybrid states formation, closure of the ribosomal L1 stalk domain, and subunit ratcheting. Here, by imaging of the pretranslocation ribosome complex from multiple structural perspectives using two- and three-color single-molecule fluorescence resonance energy transfer, we observe that tRNA hybrid states formation and L1 stalk closure, events central to the unlocking mechanism, are not tightly coupled. These findings reveal that the unlocked state is achieved through a stochastic-multistep process, where the extent of conformational coupling depends on the nature of tRNA substrates. These data suggest that cellular mechanisms affecting the coupling of conformational processes on the ribosome may regulate the process of translation elongation.
PDF
