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IVUE32, an elliptical in-vacuum undulator, is being developed at Helmholtz-Zentrum Berlin. The 2.5m long device with a period length of 32mm and a minimum gap of about 7mm is to be installed in the BESSY II storage ring. Allowing not only gap changes but also longitudinal shifts puts novel design challenges on the tapers at the entrance and exit of the undulator. The proximity of this complex structure to the electron beam makes the device susceptible to wakefield effects which can influence beam stability. A complete understanding of these phenomena is required prior to installation and operation. To understand and measure the IVU’s impedance characteristic s a Goubau-line test stand is being designed to accompany simulations. Taper prototypes will be presented alongside simulations and measurements of their impedance characteristics.

For Laser WakeField Accelerators with dedicated applications, the role of the transport line is essential, as its mission is to drive the accelerated beam from the plasma exit to the application, where all the requirements on beam quality should be met. This article investigates a two-quadrupole transport line with typical beam parameters at its entrance and exit. Consequences on its capacities and limits are discussed, considering the emittance growth that can be significant.

Design of the gas-diffusion process in a porous material is challenging because a contracted pore aperture is a prerequisite, whereas the channel traffic of guest molecules is regulated by the flexible and dynamic motions of nanochannels. Here, we present the rational design of a diffusion-regulatory system in a porous coordination polymer (PCP) in which flip-flop molecular motions within the framework structure provide kinetic gate functions that enable efficient gas separation and storage. The PCP shows substantial temperature-responsive adsorption in which the adsorbate molecules are differentiated by each gate-admission temperature, facilitating kinetics-based gas separations of oxygen/argon and ethylene/ethane with high selectivities of ~350 and ~75, respectively. Additionally, we demonstrate the long-lasting physical encapsulation of ethylene at ambient conditions, owing to strongly impeded diffusion in distinctive nanochannels.

The JCNS has been developing and using in-situ polarized neutron spin filters for many applications. The system used for analysis on MARIA and polarization for TOPAS were completed about 10 years ago with the MARIA system in standard operation for users and the TOPAS system employed for a long measurement on the POLI instrument. In the meantime we are progressing on several new in-situ polarizers based on these first two but with additional innovations. The KWS-1 analyzer device which was recently used in tests at TU Delft and ISIS is essentially a 50%-sized copy of the MARIA device. The two devices in construction for polarization and analysis on POLI for hot neutrons feature magic-boxes with angled plates on both the entrance and exit sides to minimize overal length and the polarizer device will employ an additional passive magnetic shield of soft iron so that it can operate inside the stray field area of a 8-T vertical (compensated) sample magnet. We will summarize the current status of our 3He neutron spin filters and provide extra focus on the technical aspects and measured performance characteristics of the new devices for KWS-1 and POLI in particular.

The optical design of the ultrahigh-resolution RIXS beamline, which is currently developed at NanoTerasu in Japan, is described. The main goal of this beamline is to perform ultrahigh-resolution RIXS measurements with a total energy resolution of <10 meV at 250–1000 eV with E /Δ E >150,000 for both beamline and RIXS spectrometer. To achieve the ultra-high resolution, a 2D-RIXS spectrometer using energy-dispersive X-ray is employed to compensate for lower throughput at higher energy resolution, and the optics of the beamline is optimized for the 2D-RIXS spectrometer. A vertically dispersing in-focus variable-included-angle varied-line-spacing plane grating monochromator is employed for the beamline, with an entrance slit to ensure the ultrahigh resolution. First and second mirrors focus X-ray on entrance slits vertically and horizontally, respectively, and the divergent X-ray is irradiated onto the grating. For the 2D-RIXS spectrometer, there is no exit slit, and the vertically energy-dispersed X-ray is irradiated directly onto a sample. In front of the sample, X-ray is horizontally refocused by a Wolter type-I mirror. The expected horizontal focus size at the sample is ~0.7 μm. The expected photon flux is ~1×10 11 photons/s at 500–1000 eV with a virtual slit width of 2 μm required for E /Δ E >150,000. The height of the dispersed X-ray available in the 2D-RIXS spectrometer is ~120 μm, which allows the use of a remarkably high flux of ~6×10 12 photons/s, and the beamline will serve as an ultrahigh-resolution and high-efficiency RIXS facility.

The study focuses on the potential problems with tourism that might be seen in and around the city of Agra and the areas that need to change for improved tourism. The current study is conceptual and exploratory in character. In order to identify the problem areas and current difficulties facing the tourism business, data were gathered from secondary sources such as research journals, books, newspaper articles, expert interviews, and hoteliers' comments. Websites were also consulted. The study's focus is on the existing human resource practices in the tourism sector in and around the city of Agra. This study also discusses many problems and difficulties with financial and operational procedures. Findings show that the Agra tourism business faces numerous problems, including \"Backpacker tourists,\" a weak management system, subpar infrastructure, and dissatisfied visitors. Pollution may have given the world's most renowned monument to love a yellowish hue on top of its white marble, doing what seems to be irreparable damage. The mausoleum and its integrated complex of buildings are estimated to have brought in Rs 21.84 crore, primarily from entrance fees. However, in the most recent fiscal year, the authorities only allocated Rs 2.85 crore, or a small portion of the revenue, for Taj upkeep and repairs. Heritage experts have cautioned that much more will be required to maintain the edifice because of the very filthy Yamuna making a massive loop to almost touching distance of the northern face.

Molecular-motor coordinationThe proteasome is a cytosolic molecular machine that recognizes and degrades unneeded or damaged proteins that have been tagged with ubiquitin. A heterohexameric adenosine triphosphatase motor pulls the substrate into the proteolytic chamber, while at the same time, a protein located at the entrance of this motor removes the ubiquitin. De la Peña et al. trapped the substrate inside the motor by inhibiting removal of ubiquitin. This allowed them to determine cryo–electron microscopy structures in the presence of substrate and adenosine triphosphate (ATP). The findings distinguish three sequential conformational states that show how ATP binding, hydrolysis, and phosphate release are coordinated between the six subunits of the motor to cause the conformational changes that translocate the substrate through the proteasome.Science, this issue p. eaav0725INTRODUCTIONAs the major protease in eukaryotic cells and the final component of the ubiquitin-proteasome system, the 26S proteasome is responsible for protein homeostasis and the regulation of numerous vital processes. Misfolded, damaged, or obsolete regulatory proteins are marked for degradation by the attachment of polyubiquitin chains, which bind to ubiquitin receptors of the proteasome. A heterohexameric ring of AAA+ (ATPases associated with diverse cellular activities) subunits then uses conserved pore loops to engage, mechanically unfold, and translocate protein substrates into a proteolytic core for cleavage while the deubiquitinase Rpn11 removes substrate-attached ubiquitin chains.RATIONALEDespite numerous structural and functional studies, the mechanisms by which adenosine triphosphate (ATP) hydrolysis drives the conformational changes responsible for protein degradation remained elusive. Structures of related homohexameric AAA+ motors, in which bound substrates were stabilized with ATP analogs or hydrolysis-eliminating mutations, revealed snapshots of ATPase subunits in different nucleotide states and spiral-staircase arrangements of pore loops around the substrate. These structures gave rise to “hand-over-hand” translocation models by inferring how individual subunits may progress through various substrate-binding conformations. However, the coordination of ATP-hydrolysis steps and their mechanochemical coupling to propelling substrate were unknown.RESULTSWe present the cryo–electron microscopy (cryo-EM) structures of the actively ATP-hydrolyzing, substrate-engaged 26S proteasome with four distinct motor conformations. Stalling substrate translocation at a defined position by inhibiting deubiquitination led to trapped states in which the substrate-attached ubiquitin remains functionally bound to the Rpn11 deubiquitinase, and the scissile isopeptide bond of ubiquitin is aligned with the substrate-translocation trajectory through the AAA+ motor. Our structures suggest a ubiquitin capture mechanism, in which mechanical pulling on the substrate by the AAA+ motor delivers ubiquitin modifications directly into the Rpn11 catalytic groove and accelerates isopeptide cleavage for efficient, cotranslocational deubiquitination.These structures also show how the substrate polypeptide traverses from the Rpn11 deubiquitinase, through the AAA+ motor, and into the core peptidase. The proteasomal motor thereby adopts staircase arrangements with five substrate-engaged subunits and one disengaged subunit. Four of the substrate-engaged subunits are ATP bound, whereas the subunit at the bottom of the staircase and the disengaged subunit are bound to adenosine diphosphate (ADP).CONCLUSIONOf the four distinct motor states we observed, three apparently represent sequential stages of ATP binding, hydrolysis, and substrate translocation and hence reveal the coordination of individual steps in the ATPase cycle and their mechanochemical coupling with translocation. ATP hydrolysis occurs in the fourth substrate-engaged subunit from the top, concomitantly with exchange of ADP for ATP in the disengaged subunit. The subsequent transition, which is likely triggered by phosphate release from the fourth, posthydrolysis subunit of the staircase, then involves major conformational changes of the entire ATPase hexamer. The bottom ADP-bound subunit is displaced and the previously disengaged subunit binds the substrate at the top of the staircase, while the four engaged subunits move downward as a rigid body and translocate substrate toward the peptidase. Our likely consecutive proteasome conformations, together with previously determined substrate-free structures, suggest a sequential progression of ATPase subunits through the ATP-hydrolysis cycle. We hypothesize that, in general, hexameric AAA+ translocases function by this sequential mechanism.The 26S proteasome is the primary eukaryotic degradation machine and thus is critically involved in numerous cellular processes. The heterohexameric adenosine triphosphatase (ATPase) motor of the proteasome unfolds and translocates targeted protein substrates into the open gate of a proteolytic core while a proteasomal deubiquitinase concomitantly removes substrate-attached ubiquitin chains. However, the mechanisms by which ATP hydrolysis drives the conformational changes responsible for these processes have remained elusive. Here we present the cryo–electron microscopy structures of four distinct conformational states of the actively ATP-hydrolyzing, substrate-engaged 26S proteasome. These structures reveal how mechanical substrate translocation accelerates deubiquitination and how ATP-binding, -hydrolysis, and phosphate-release events are coordinated within the AAA+ (ATPases associated with diverse cellular activities) motor to induce conformational changes and propel the substrate through the central pore.

Despite the voluminous literature on the potentials of single-sex schools, there is no consensus on the effects of single-sex schools because of student selection of school types. We exploit a unique feature of schooling in Seoul—the random assignment of students into single-sex versus coeducational high schools—to assess causal effects of single-sex schools on college entrance exam scores and college attendance. Our validation of the random assignment shows comparable socioeconomic backgrounds and prior academic achievement of students attending single-sex schools and coeducational schools, which increases the credibility of our causal estimates of single-sex school effects. The three-level hierarchical model shows that attending all-boys schools or all-girls schools, rather than coeducational schools, is significantly associated with higher average scores on Korean and English test scores. Applying the school district fixed-effects models, we find that single-sex schools produce a higher percentage of graduates who attended four-year colleges and a lower percentage of graduates who attended two-year junior colleges than do coeducational schools. The positive effects of single-sex schools remain substantial, even after we take into account various school-level variables, such as teacher quality, the student-teacher ratio, the proportion of students receiving lunch support, and whether the schools are public or private.