In this paper we present a high repetition rate experimental platform for examining the spatial structure and evolution of Biermann-generated magnetic fields in laser-produced plasmas.We have extended the work of prio...In this paper we present a high repetition rate experimental platform for examining the spatial structure and evolution of Biermann-generated magnetic fields in laser-produced plasmas.We have extended the work of prior experiments,which spanned over millimeter scales,by spatially measuring magnetic fields in multiple planes on centimeter scales over thousands of laser shots.Measurements with magnetic fiux probes show azimuthally symmetric magnetic fields that range from 60 G at 0.7 cm from the target to 7 G at 4.2 cm from the target.The expansion rate of the magnetic fields and evolution of current density structures are also mapped and examined.Electron temperature and density of the laser-produced plasma are measured with optical Thomson scattering and used to directly calculate a magnetic Reynolds number of 1.4×10^(4),confirming that magnetic advection is dominant at≥1.5 cm from the target surface.The results are compared to FLASH simulations,which show qualitative agreement with the data.展开更多
We present a new experimental platform for studying laboratory astrophysics that combines a high-intensity, highrepetition-rate laser with the Large Plasma Device at the University of California, Los Angeles. To demon...We present a new experimental platform for studying laboratory astrophysics that combines a high-intensity, highrepetition-rate laser with the Large Plasma Device at the University of California, Los Angeles. To demonstrate the utility of this platform, we show the first results of volumetric, highly repeatable magnetic field and electrostatic potential measurements, along with derived quantities of electric field, charge density and current density, of the interaction between a super-Alfv′enic laser-produced plasma and an ambient, magnetized plasma.展开更多
Eukaryotic organisms are equipped with quality-control mechanisms that survey protein folding in the endoplasmic reticulum (ER) and remove non-native proteins by ER-associated degradation (ERAD). Recent research has s...Eukaryotic organisms are equipped with quality-control mechanisms that survey protein folding in the endoplasmic reticulum (ER) and remove non-native proteins by ER-associated degradation (ERAD). Recent research has shown that cytokinin-degrading CKX proteins are subjected to ERAD during plant development. The mechanisms of plant ERAD, including the export of substrate proteins from the ER, are not fully understood and the molecular components involved in the ERAD of CKX are unknown. We show that heavy metal-associated isoprenylated plant proteins (HIPP) interact specifically with CKX proteins synthesized in the ER and processed by ERAD. CKX-HIPP protein complexes were detected at the ER as well as in the cytosol, suggesting that the complexes involve retrotranslocated CKX protein species. Altered CKX levels in HIPP-overexpressing and higher-order hipp mutant plants suggest that the studied HIPP proteins control the ERAD of CKX. Deregulation of CKX proteins caused corresponding changes in the cytokinin signaling activity and triggered typical morphological cytokinin responses. Notably, transcriptional repression of HIPP genes by cytokinin indicates a feedback regulatory mechanism of cytokinin homeostasis and signaling responses. Moreover, the loss of HIPP genes constitutively activates the unfolded protein response and compromises the ER stress tolerance, supporting the conclusion that HIPPs represent novel functional components of plant ERAD.展开更多
基金the Department of Energy(DOE)under award number DE-SC0019011the National Nuclear Security Administration(NNSA)Center for Matter under Extreme Conditions under award number DE-NA0003842+1 种基金the National Science Foundation Graduate Fellowship Research Program under award number DGE-1650604support by the U.S.DOE NNSA under Subcontracts 536203 and 630138 with Los Alamos National Laboratory,Subcontract B632670 with LLNL and support from the Cooperative Agreement DE-NA0003856 to the Laboratory for Laser Energetics University of Rochester。
文摘In this paper we present a high repetition rate experimental platform for examining the spatial structure and evolution of Biermann-generated magnetic fields in laser-produced plasmas.We have extended the work of prior experiments,which spanned over millimeter scales,by spatially measuring magnetic fields in multiple planes on centimeter scales over thousands of laser shots.Measurements with magnetic fiux probes show azimuthally symmetric magnetic fields that range from 60 G at 0.7 cm from the target to 7 G at 4.2 cm from the target.The expansion rate of the magnetic fields and evolution of current density structures are also mapped and examined.Electron temperature and density of the laser-produced plasma are measured with optical Thomson scattering and used to directly calculate a magnetic Reynolds number of 1.4×10^(4),confirming that magnetic advection is dominant at≥1.5 cm from the target surface.The results are compared to FLASH simulations,which show qualitative agreement with the data.
基金supported by the DTRA under Contract No.HDTRA1-12-1-0024the DOE under Contract Nos.DESC0006538 and DE-SC0017900performed at the UCLA Basic Plasma Science Facility(Ba PSF),supported by the DOE and NSF
文摘We present a new experimental platform for studying laboratory astrophysics that combines a high-intensity, highrepetition-rate laser with the Large Plasma Device at the University of California, Los Angeles. To demonstrate the utility of this platform, we show the first results of volumetric, highly repeatable magnetic field and electrostatic potential measurements, along with derived quantities of electric field, charge density and current density, of the interaction between a super-Alfv′enic laser-produced plasma and an ambient, magnetized plasma.
基金This work was supported by grants from the Austrian Science Fund(P 30945)Deutsche Forschungsgemeinschaft(WE 4325/1-1 and WE 4325/2-2)from the Ministry of Education,Youth and Sports of the Czech Republic(European Regional Development Fund-Project"Plants as a tool for sustainable global development"no.CZ.02.1.01/0.0/0.0/16_019/0000827).
文摘Eukaryotic organisms are equipped with quality-control mechanisms that survey protein folding in the endoplasmic reticulum (ER) and remove non-native proteins by ER-associated degradation (ERAD). Recent research has shown that cytokinin-degrading CKX proteins are subjected to ERAD during plant development. The mechanisms of plant ERAD, including the export of substrate proteins from the ER, are not fully understood and the molecular components involved in the ERAD of CKX are unknown. We show that heavy metal-associated isoprenylated plant proteins (HIPP) interact specifically with CKX proteins synthesized in the ER and processed by ERAD. CKX-HIPP protein complexes were detected at the ER as well as in the cytosol, suggesting that the complexes involve retrotranslocated CKX protein species. Altered CKX levels in HIPP-overexpressing and higher-order hipp mutant plants suggest that the studied HIPP proteins control the ERAD of CKX. Deregulation of CKX proteins caused corresponding changes in the cytokinin signaling activity and triggered typical morphological cytokinin responses. Notably, transcriptional repression of HIPP genes by cytokinin indicates a feedback regulatory mechanism of cytokinin homeostasis and signaling responses. Moreover, the loss of HIPP genes constitutively activates the unfolded protein response and compromises the ER stress tolerance, supporting the conclusion that HIPPs represent novel functional components of plant ERAD.
