| 1. |
- El Omari, Kamel, et al.
(författare)
-
Experimental phasing opportunities for macromolecular crystallography at very long wavelengths
- 2023
-
Ingår i: Communications Chemistry. - : Nature Publishing Group. - 2399-3669. ; 6:1
-
Tidskriftsartikel (refereegranskat)abstract
- Despite recent advances in cryo-electron microscopy and artificial intelligence-based model predictions, a significant fraction of structure determinations by macromolecular crystallography still requires experimental phasing, usually by means of single-wavelength anomalous diffraction (SAD) techniques. Most synchrotron beamlines provide highly brilliant beams of X-rays of between 0.7 and 2 Å wavelength. Use of longer wavelengths to access the absorption edges of biologically important lighter atoms such as calcium, potassium, chlorine, sulfur and phosphorus for native-SAD phasing is attractive but technically highly challenging. The long-wavelength beamline I23 at Diamond Light Source overcomes these limitations and extends the accessible wavelength range to λ = 5.9 Å. Here we report 22 macromolecular structures solved in this extended wavelength range, using anomalous scattering from a range of elements which demonstrate the routine feasibility of lighter atom phasing. We suggest that, in light of its advantages, long-wavelength crystallography is a compelling option for experimental phasing.
|
|
| 2. |
- Engel, Philipp, et al.
(författare)
-
The Bee Microbiome: Impact on Bee Health and Model for Evolution and Ecology of Host-Microbe Interactions
- 2016
-
Ingår i: mBio. - : American Society for Microbiology. - 2161-2129 .- 2150-7511. ; 7:2
-
Forskningsöversikt (refereegranskat)abstract
- As pollinators, bees are cornerstones for terrestrial ecosystem stability and key components in agricultural productivity. All animals, including bees, are associated with a diverse community of microbes, commonly referred to as the micro biome. The bee micro biome is likely to be a crucial factor affecting host health. However, with the exception of a few pathogens, the impacts of most members of the bee microbiome on host health are poorly understood. Further, the evolutionary and ecological forces that shape and change the microbiome are unclear. Here, we discuss recent progress in our understanding of the bee microbiome, and we present challenges associated with its investigation. We conclude that global coordination of research efforts is needed to fully understand the complex and highly dynamic nature of the interplay between the bee micro biome, its host, and the environment. High-throughput sequencing technologies are ideal for exploring complex biological systems, including host-microbe interactions. To maximize their value and to improve assessment of the factors affecting bee health, sequence data should be archived, curated, and analyzed in ways that promote the synthesis of different studies. To this end, the BeeBiome consortium aims to develop an online database which would provide reference sequences, archive metadata, and host analytical resources. The goal would be to support applied and fundamental research on bees and their associated microbes and to provide a collaborative framework for sharing primary data from different research programs, thus furthering our understanding of the bee microbiome and its impact on pollinator health.
|
|
| 3. |
- Joshi, Siddarth Koduru, et al.
(författare)
-
Space QUEST mission proposal : experimentally testing decoherence due to gravity
- 2018
-
Ingår i: New Journal of Physics. - : IOP Publishing. - 1367-2630. ; 20
-
Tidskriftsartikel (refereegranskat)abstract
- Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that quantum correlations, such as entanglement, may exhibit different behavior to purely classical correlations in curved space. By measuring this effect or lack thereof, we can test the hypotheses behind several such models. For instance, as predicted by Ralph et al [5] and Ralph and Pienaar [1], a bipartite entangled system could decohere if each particle traversed through a different gravitational field gradient. We propose to study this effect in a ground to space uplink scenario. We extend the above theoretical predictions of Ralph and coworkers and discuss the scientific consequences of detecting/failing to detect the predicted gravitational decoherence. We present a detailed mission design of the European Space Agency's Space QUEST (Space-Quantum Entanglement Space Test) mission, and study the feasibility of the mission scheme.
|
|
| 4. |
- Dogiel, Vladimir A., et al.
(författare)
-
Origin of Thermal and Non-Thermal Hard X-Ray Emissionfrom the Galactic Center
- 2009
-
Ingår i: Publications of the Astronomical Society of Japan. - : Oxford University Press. - 0004-6264 .- 2053-051X. ; 61:5, s. 1099-1105
-
Tidskriftsartikel (refereegranskat)abstract
- We analyse new results of Chandra and Suzaku Observatories which found a flux of hard X-ray emission from the compact region around Sgr A∗ (r ∼ 100 pc). We suppose that this emission is generated by accretion processes onto the central supermassive blackhole when an unbound part of captured stars obtains an additional momentum. As a result a flux of subrelativistic protons is generated near the galactic center which heats the background plasma up to temperatures about 6–10 keV and produces by inverse bremsstrahlung a flux of non-thermal X-ray emission in the energy range above 10 keV.
|
|
