Structure determination of protein-peptide complexes from NMR chemical shift data using MELD.

Intrinsically disordered regions of proteins often mediate important protein-protein interactions. However, the folding upon binding nature of many polypeptide-protein interactions limits the ability of modeling tools to predict structures of such complexes. To address this problem, we have taken a tandem approach combining NMR chemical shift data and molecular simulations to determine structures of peptide-protein complexes. Here, we demonstrate this approach for polypeptide com-plexes formed with the extraterminal (ET) domain of bromo and extraterminal domain (BET) proteins, which exhibit a high degree of binding plasticity. This system is particularly challenging as the binding process includes allosteric changes across the ET receptor upon binding, and the polypeptide binding partners can form different conformations (e.g., helices and hair-pins) in the complex. In a blind study, the new approach successfully modeled bound-state conformations and binding pos-es, using only backbone chemical shift data, in excellent agreement with experimentally-determined structures. The approach also predicts relative binding affinities of different peptides. This hybrid MELD-NMR approach provides a powerful new tool for structural analysis of protein-polypeptide complexes in the low NMR information content regime, which can be used successfully for flexible systems where one polypeptide binding partner folds upon complex formation.

Tailoring of Magnesium Substitution on Structure and Magnetic Properties of Lithium Ferrites

In this study is reported influence of Mg2+ doping on structure and magnetic properties of nano-sized Li0.5Fe2.5-XMgXO4 (0.0, 0.2, 0.4, 0.6, 0.8) synthesized using sol-gel auto-combustion method. The X-ray diffractometric and Mössbauer data analysis of samples confirmed the formation of pure Li0.5Fe2.5-XMgXO4 nanoparticles ranges crystallite size from 15 nm to 35 nm. Iron ions are redistributed on the A and B sites in a ratio of approximately 4:6, and magnesium ions 8:2, respectively. The advantages of the B position of the above ions are as follows: Li+>Fe3+>Mg2+. RT-Mössbauer indicated the presence of 57Fe in both sublattices. Position identification was performed based on the distribution of the over exchange fields and isomeric shift data. Magnetic characteristics were obtained for rings made of synthesized material. They showed a non-monotonic dependence on the composition and found significantly higher rates compared to similar materials obtained by solid-phase synthesis.

Real-Time Telemetry Data Monitoring System on Soil Movement of Railway Tracks

A telemetry data monitoring system is needed to monitor land shifting. This system consists of an ATMega328 microcontroller, a Linear Variable Differential Transformer (LVDT) and a rheostat, an accelerometer sensor, a rain gauge tipping bucket, and the HC-12 radio telemetry module. Normally, the LVDT reads the land shift in the 0-20 mm range, the Rheostat is capable of shifting up to 66 mm, the accelerometer sensor reads less than 20 deg of data, and the rain gauge tipping bucket sensor creates the amount of rainfall below 50 mm/hour which is then sending real-time data regularly for 24 hours. The buzzer installed in the field will sound if the LVDT reads land shift more than 30 mm, Rheostat more than 51 mm, and the accelerometer sensor reads data more than 45 deg; also, the rain gauge tipping bucket sensor reads more than 70 mm/hour. This test creates parameter data. So that shift data can be monitored.

Registered Nurses’ Experiences Taking Breaks on Night Shift: A Qualitative Analysis

Background: Fatigue mitigation strategies among night shift workers can include deliberate use of restful work breaks, taking naps, and consuming caffeine. However, nurses have frequently reported missing break opportunities, and the rationale for missed breaks remains unclear. The purpose of this study was to describe and interpret the lived experience of hospital night shift nurses taking breaks and the meaning of this phenomenon as it relates to the workplace. Methods: Registered nurses ( n = 16) from a U.S. community hospital were interviewed about how they took rest breaks during their shift. Data were analyzed with methods consistent to interpretive phenomenology. Findings: Identified themes about the breaks included (a) breaks are a time to eat, (b) breaks are inconsistently supported by unit-level structures and processes, and (c) breaks are a luxury, not a right. Conclusions/Applications to Practice: Nurses in this study reported an absence of consistent and restorative breaks. Organizations should analyze gaps within systems and processes to optimize a consistent, restorative nature of the break experience among nurses working night shift.

Non-parametric reconstruction of the cosmological jerk parameter

The cosmological jerk parameter j is reconstructed in a non-parametric way from observational data independent of a fiducial cosmological model. The Cosmic Chronometer data as well as the Supernovae data (the Pantheon compilation) are used for the purpose. The reconstructed values are found to be consistent with the standard $$\Lambda $$ Λ CDM model within the $$2\sigma $$ 2 σ confidence level. The model dependent sets like Baryon Acoustic Oscillation and the CMB Shift data are also included thereafter, which does not significantly help in improving or de-proving the confidence level in favour of $$\Lambda $$ Λ CDM. The deceleration parameter q is also reconstructed from the same data sets. This is used to find the effective equation of state parameter for the model independent datasets only. $$\Lambda $$ Λ CDM model is excluded for some part of the evolution in $$1\sigma $$ 1 σ , but is definitely included in $$2\sigma $$ 2 σ in the domain ($$0 \le z \le 2.36$$ 0 ≤ z ≤ 2.36 ) of all the reconstructions.

High-resolution cryo-EM using beam-image shift at 200 keV

Recent advances in single-particle cryo-electron microscopy (cryo-EM) data collection utilize beam-image shift to improve throughput. Despite implementation on 300 keV cryo-EM instruments, it remains unknown how well beam-image-shift data collection affects data quality on 200 keV instruments and the extent to which aberrations can be computationally corrected. To test this, a cryo-EM data set for aldolase was collected at 200 keV using beam-image shift and analyzed. This analysis shows that the instrument beam tilt and particle motion initially limited the resolution to 4.9 Å. After particle polishing and iterative rounds of aberration correction in RELION, a 2.8 Å resolution structure could be obtained. This analysis demonstrates that software correction of microscope aberrations can provide a significant improvement in resolution at 200 keV.

Temperature-Independent Cuprate Pseudogap from Planar Oxygen NMR

Planar oxygen nuclear magnetic resonance (NMR) relaxation and shift data from all cuprate superconductors available in the literature are analyzed. They reveal a temperature-independent pseudogap at the Fermi surface, which increases with decreasing doping in family-specific ways, i.e., for some materials, the pseudogap is substantial at optimal doping while for others it is nearly closed at optimal doping. The states above the pseudogap, or in its absence are similar for all cuprates and doping levels, and Fermi liquid-like. If the pseudogap is assumed exponential it can be as large as about 1500 K for the most underdoped systems, relating it to the exchange coupling. The pseudogap can vary substantially throughout a material, being the cause of cuprate inhomogeneity in terms of charge and spin, so consequences for the NMR analyses are discussed. This pseudogap appears to be in agreement with the specific heat data measured for the YBaCuO family of materials, long ago. Nuclear relaxation and shift show deviations from this scenario near Tc, possibly due to other in-gap states.

High-resolution cryo-EM using beam-image shift at 200 keV

ABSTRACTRecent advances in single-particle cryo-electron microscopy (cryo-EM) data collection utilizes beam-image shift to improve throughput. Despite implementation on 300 keV cryo-EM instruments, it remains unknown how well beam-image shift data collection affects data quality on 200 keV instruments and how much aberrations can be computationally corrected. To test this, we collected and analyzed a cryo-EM dataset of aldolase at 200 keV using beam-image shift. This analysis shows that beam tilt on the instrument initially limited the resolution of aldolase to 4.9Å. After iterative rounds of aberration correction and particle polishing in RELION, we were able to obtain a 2.8Å structure. This analysis demonstrates that software correction of microscope aberrations can provide a significant improvement in resolution at 200 keV.