sec

India plans over 100 flights during second phase of evacuation abroad

To link countries where no Indian carrier presently flies




sec

K7 Computing bags performance awards for security solution

The city-based K7 Computing Pvt Ltd, provider of cyber security solutions, has topped the winners list for the Advanced+ Performance Award from AV-Com




sec

Indian, Chinese troops clash in Sikkim sector

Many of them sustained minor injuries in the clash near Naku La in the Sikkim sector along the Sino-Indo border on Saturday




sec

Scientific instrument Femtosecond X-ray Experiments (FXE): instrumentation and baseline experimental capabilities

The European X-ray Free-Electron Laser (EuXFEL) delivers extremely intense (>1012 photons pulse−1 and up to 27000 pulses s−1), ultrashort (<100 fs) and transversely coherent X-ray radiation, at a repetition rate of up to 4.5 MHz. Its unique X-ray beam parameters enable novel and groundbreaking experiments in ultrafast photochemistry and material sciences at the Femtosecond X-ray Experiments (FXE) scientific instrument. This paper provides an overview of the currently implemented experimental baseline instrumentation and its performance during the commissioning phase, and a preview of planned improvements. FXE's versatile instrumentation combines the simultaneous application of forward X-ray scattering and X-ray spectroscopy techniques with femtosecond time resolution. These methods will eventually permit exploitation of wide-angle X-ray scattering studies and X-ray emission spectroscopy, along with X-ray absorption spectroscopy, including resonant inelastic X-ray scattering and X-ray Raman scattering. A suite of ultrafast optical lasers throughout the UV–visible and near-IR ranges (extending up to mid-IR in the near future) with pulse length down to 15 fs, synchronized to the X-ray source, serve to initiate dynamic changes in the sample. Time-delayed hard X-ray pulses in the 5–20 keV range are used to probe the ensuing dynamic processes using the suite of X-ray probe tools. FXE is equipped with a primary monochromator, a primary and secondary single-shot spectrometer, and a timing tool to correct the residual timing jitter between laser and X-ray pulses.




sec

Fast identification of mineral inclusions in diamond at GSECARS using synchrotron X-ray microtomography, radiography and diffraction

Mineral inclusions in natural diamond are widely studied for the insight that they provide into the geochemistry and dynamics of the Earth's interior. A major challenge in achieving thorough yet high rates of analysis of mineral inclusions in diamond derives from the micrometre-scale of most inclusions, often requiring synchrotron radiation sources for diffraction. Centering microinclusions for diffraction with a highly focused synchrotron beam cannot be achieved optically because of the very high index of refraction of diamond. A fast, high-throughput method for identification of micromineral inclusions in diamond has been developed at the GeoSoilEnviro Center for Advanced Radiation Sources (GSECARS), Advanced Photon Source, Argonne National Laboratory, USA. Diamonds and their inclusions are imaged using synchrotron 3D computed X-ray microtomography on beamline 13-BM-D of GSECARS. The location of every inclusion is then pinpointed onto the coordinate system of the six-circle goniometer of the single-crystal diffractometer on beamline 13-BM-C. Because the bending magnet branch 13-BM is divided and delivered into 13-BM-C and 13-BM-D stations simultaneously, numerous diamonds can be examined during coordinated runs. The fast, high-throughput capability of the methodology is demonstrated by collecting 3D diffraction data on 53 diamond inclusions from Juína, Brazil, within a total of about 72 h of beam time.




sec

Microsecond time-resolved X-ray diffraction for the investigation of fatigue behavior during ultrasonic fatigue loading

A new method based on time-resolved X-ray diffraction is proposed in order to measure the elastic strain and stress during ultrasonic fatigue loading experiments. Pure Cu was chosen as an example material for the experiments using a 20 kHz ultrasonic fatigue machine mounted on the six-circle diffractometer available at the DiffAbs beamline on the SOLEIL synchrotron facility in France. A two-dimensional hybrid pixel X-ray detector (XPAD3.2) was triggered by the strain gage signal in a synchronous data acquisition scheme (pump–probe-like). The method enables studying loading cycles with a period of 50 µs, achieving a temporal resolution of 1 µs. This allows a precise reconstruction of the diffraction patterns during the loading cycles. From the diffraction patterns, the position of the peaks, their shifts and their respective broadening can be deduced. The diffraction peak shift allows the elastic lattice strain to be estimated with a resolution of ∼10−5. Stress is calculated by the self-consistent scale-transition model through which the elastic response of the material is estimated. The amplitudes of the cyclic stresses range from 40 to 120 MPa and vary linearly with respect to the displacement applied by the ultrasonic machine. Moreover, the experimental results highlight an increase of the diffraction peak broadening with the number of applied cycles.




sec

Picosecond pump–probe X-ray scattering at the Elettra SAXS beamline

A new setup for picosecond pump–probe X-ray scattering at the Austrian SAXS beamline at Elettra-Sincrotrone Trieste is presented. A high-power/high-repetion-rate laser has been installed on-site, delivering UV/VIS/IR femto­second-pulses in-sync with the storage ring. Data acquisition is achieved by gating a multi-panel detector, capable of discriminating the single X-ray pulse in the dark-gap of the Elettra hybrid filling mode. Specific aspects of laser- and detection-synchronization, on-line beam steering as well protocols for spatial and temporal overlap of laser and X-ray beam are also described. The capabilities of the setup are demonstrated by studying transient heat-transfer in an In/Al/GaAs superlattice structure and results are confirmed by theoretical calculations.




sec

Time dependence of X-ray polarizability of a crystal induced by an intense femtosecond X-ray pulse

The time evolution of the electron density and the resulting time dependence of the X-ray polarizability of a crystal irradiated by highly intense XFEL femtosecond pulses is investigated theoretically. Rate equations for bound electrons and the Boltzmann equation for the unbound electron gas are used in calculations.




sec

The indexing ambiguity in serial femtosecond crystallography (SFX) resolved using an expectation maximization algorithm

An expectation maximization algorithm is implemented to resolve the indexing ambiguity which arises when merging data from many crystals in protein crystallography, especially in cases where partial reflections are recorded in serial femtosecond crystallography (SFX) at XFELs.








sec

Sub-millisecond time-resolved small-angle neutron scattering measurements at NIST

Instrumentation for time-resolved small-angle neutron scattering measurements with sub-millisecond time resolution, based on Gähler's TISANE (time-involved small-angle neutron experiments) concept, is in operation at NIST's Center for Neutron Research. This implementation of the technique includes novel electronics for synchronizing the neutron pulses from high-speed counter-rotating choppers with a periodic stimulus applied to a sample. Instrumentation details are described along with measurements demonstrating the utility of the technique for elucidating the reorientation dynamics of anisometric magnetic particles.




sec

Catalytically important damage-free structures of a copper nitrite reductase obtained by femtosecond X-ray laser and room-temperature neutron crystallography

Copper-containing nitrite reductases (CuNiRs) that convert NO2− to NO via a CuCAT–His–Cys–CuET proton-coupled redox system are of central importance in nitrogen-based energy metabolism. These metalloenzymes, like all redox enzymes, are very susceptible to radiation damage from the intense synchrotron-radiation X-rays that are used to obtain structures at high resolution. Understanding the chemistry that underpins the enzyme mechanisms in these systems requires resolutions of better than 2 Å. Here, for the first time, the damage-free structure of the resting state of one of the most studied CuNiRs was obtained by combining X-ray free-electron laser (XFEL) and neutron crystallography. This represents the first direct comparison of neutron and XFEL structural data for any protein. In addition, damage-free structures of the reduced and nitrite-bound forms have been obtained to high resolution from cryogenically maintained crystals by XFEL crystallography. It is demonstrated that AspCAT and HisCAT are deprotonated in the resting state of CuNiRs at pH values close to the optimum for activity. A bridging neutral water (D2O) is positioned with one deuteron directed towards AspCAT Oδ1 and one towards HisCAT N∊2. The catalytic T2Cu-ligated water (W1) can clearly be modelled as a neutral D2O molecule as opposed to D3O+ or OD−, which have previously been suggested as possible alternatives. The bridging water restricts the movement of the unprotonated AspCAT and is too distant to form a hydrogen bond to the O atom of the bound nitrite that interacts with AspCAT. Upon the binding of NO2− a proton is transferred from the bridging water to the Oδ2 atom of AspCAT, prompting electron transfer from T1Cu to T2Cu and reducing the catalytic redox centre. This triggers the transfer of a proton from AspCAT to the bound nitrite, enabling the reaction to proceed.




sec

High-throughput structures of protein–ligand complexes at room temperature using serial femtosecond crystallography

High-throughput X-ray crystal structures of protein–ligand complexes are critical to pharmaceutical drug development. However, cryocooling of crystals and X-ray radiation damage may distort the observed ligand binding. Serial femtosecond crystallography (SFX) using X-ray free-electron lasers (XFELs) can produce radiation-damage-free room-temperature structures. Ligand-binding studies using SFX have received only modest attention, partly owing to limited beamtime availability and the large quantity of sample that is required per structure determination. Here, a high-throughput approach to determine room-temperature damage-free structures with excellent sample and time efficiency is demonstrated, allowing complexes to be characterized rapidly and without prohibitive sample requirements. This yields high-quality difference density maps allowing unambiguous ligand placement. Crucially, it is demonstrated that ligands similar in size or smaller than those used in fragment-based drug design may be clearly identified in data sets obtained from <1000 diffraction images. This efficiency in both sample and XFEL beamtime opens the door to true high-throughput screening of protein–ligand complexes using SFX.




sec

A fixed-target platform for serial femtosecond crystallography in a hydrated environment

For serial femtosecond crystallography at X-ray free-electron lasers, which entails collection of single-pulse diffraction patterns from a constantly refreshed supply of microcrystalline sample, delivery of the sample into the X-ray beam path while maintaining low background remains a technical challenge for some experiments, especially where this methodology is applied to relatively low-ordered samples or those difficult to purify and crystallize in large quantities. This work demonstrates a scheme to encapsulate biological samples using polymer thin films and graphene to maintain sample hydration in vacuum conditions. The encapsulated sample is delivered into the X-ray beam on fixed targets for rapid scanning using the Roadrunner fixed-target system towards a long-term goal of low-background measurements on weakly diffracting samples. As a proof of principle, we used microcrystals of the 24 kDa rapid encystment protein (REP24) to provide a benchmark for polymer/graphene sandwich performance. The REP24 microcrystal unit cell obtained from our sandwiched in-vacuum sample was consistent with previously established unit-cell parameters and with those measured by us without encapsulation in humidified helium, indicating that the platform is robust against evaporative losses. While significant scattering from water was observed because of the sample-deposition method, the polymer/graphene sandwich itself was shown to contribute minimally to background scattering.




sec

Open-access and free articles in Acta Crystallographica Section D: Biological Crystallography




sec

DatView: a graphical user interface for visualizing and querying large data sets in serial femtosecond crystallography

DatView is a new graphical user interface (GUI) for plotting parameters to explore correlations, identify outliers and export subsets of data. It was designed to simplify and expedite analysis of very large unmerged serial femtosecond crystallography (SFX) data sets composed of indexing results from hundreds of thousands of microcrystal diffraction patterns. However, DatView works with any tabulated data, offering its functionality to many applications outside serial crystallography. In DatView's user-friendly GUI, selections are drawn onto plots and synchronized across all other plots, so correlations between multiple parameters in large multi-parameter data sets can be rapidly identified. It also includes an item viewer for displaying images in the current selection alongside the associated metadata. For serial crystallography data processed by indexamajig from CrystFEL [White, Kirian, Martin, Aquila, Nass, Barty & Chapman (2012). J. Appl. Cryst. 45, 335–341], DatView generates a table of parameters and metadata from stream files and, optionally, the associated HDF5 files. By combining the functionality of several commonly needed tools for SFX in a single GUI that operates on tabulated data, the time needed to load and calculate statistics from large data sets is reduced. This paper describes how DatView facilitates (i) efficient feedback during data collection by examining trends in time, sample position or any parameter, (ii) determination of optimal indexing and integration parameters via the comparison mode, (iii) identification of systematic errors in unmerged SFX data sets, and (iv) sorting and highly flexible data filtering (plot selections, Boolean filters and more), including direct export of subset CrystFEL stream files for further processing.




sec

High-viscosity sample-injection device for serial femtosecond crystallography at atmospheric pressure

A sample-injection device has been developed at SPring-8 Angstrom Compact Free-Electron Laser (SACLA) for serial femtosecond crystallography (SFX) at atmospheric pressure. Microcrystals embedded in a highly viscous carrier are stably delivered from a capillary nozzle with the aid of a coaxial gas flow and a suction device. The cartridge-type sample reservoir is easily replaceable and facilitates sample reloading or exchange. The reservoir is positioned in a cooling jacket with a temperature-regulated water flow, which is useful to prevent drastic changes in the sample temperature during data collection. This work demonstrates that the injector successfully worked in SFX of the human A2A adenosine receptor complexed with an antagonist, ZM241385, in lipidic cubic phase and for hen egg-white lysozyme microcrystals in a grease carrier. The injection device has also been applied to many kinds of proteins, not only for static structural analyses but also for dynamics studies using pump–probe techniques.




sec

Application of a high-throughput microcrystal delivery system to serial femtosecond crystallography

Microcrystal delivery methods are pivotal in the use of serial femtosecond crystallography (SFX) to resolve the macromolecular structures of proteins. Here, the development of a novel technique and instruments for efficiently delivering microcrystals for SFX are presented. The new method, which relies on a one-dimensional fixed-target system that includes a microcrystal container, consumes an extremely low amount of sample compared with conventional two-dimensional fixed-target techniques at ambient temperature. This novel system can deliver soluble microcrystals without highly viscous carrier media and, moreover, can be used as a microcrystal growth device for SFX. Diffraction data collection utilizing this advanced technique along with a real-time visual servo scan system has been successfully demonstrated for the structure determination of proteinase K microcrystals at 1.85 Å resolution.




sec

Sub-millisecond time-resolved small-angle neutron scattering measurements at NIST

Instrumentation for sub-millisecond time-resolved small-angle neutron scattering measurements at NIST is described and applied to the reorientation dynamics of elongated hematite nanoparticles.





sec

Forthcoming article in Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials




sec

An extracellular domain of the EsaA membrane component of the type VIIb secretion system: expression, purification and crystallization

The membrane protein EsaA is a conserved component of the type VIIb secretion system. Limited proteolysis of purified EsaA from Staphylococcus aureus USA300 identified a stable 48 kDa fragment, which was mapped by fingerprint mass spectrometry to an uncharacterized extracellular segment of EsaA. Analysis by circular dichroism spectroscopy showed that this fragment folds into a single stable domain made of mostly α-helices with a melting point of 34.5°C. Size-exclusion chromatography combined with multi-angle light scattering indicated the formation of a dimer of the purified extracellular domain. Octahedral crystals were grown in 0.2 M ammonium citrate tribasic pH 7.0, 16% PEG 3350 using the hanging-drop vapor-diffusion method. Diffraction data were analyzed to 4.0 Å resolution, showing that the crystals belonged to the enantiomorphic tetragonal space groups P41212 or P43212, with unit-cell parameters a = 197.5, b = 197.5, c = 368.3 Å, α = β = γ = 90°.




sec

Open-access and free articles in Acta Crystallographica Section F: Structural Biology and Crystallization Communications





sec

BS in Cybersecurity




sec

What are the certificates to do for a cyber security job?




sec

Smithsonian Names Eva Pell as Under Secretary for Science

Today the Smithsonian Institution announced Eva J. Pell, Senior Vice President for Research and Dean of the Graduate School at Pennsylvania State University, will be the new Under Secretary for Science at the Institution.

The post Smithsonian Names Eva Pell as Under Secretary for Science appeared first on Smithsonian Insider.




sec

Salad science: Coaxing caterpillars to reveal the secrets of their leafy desires

Testing caterpillars’ taste buds is no simple task. Just like your local salad bar, plants in the wild come in different shapes, textures and flavors. Herbivores rely on each of these cues to tell them what to eat. Deciphering this code is Lind’s task. He’s examining 40 different plant species – half invasive, half native.

The post Salad science: Coaxing caterpillars to reveal the secrets of their leafy desires appeared first on Smithsonian Insider.




sec

Laboratory tests reveal precise way to measure vertical lift in bumblebees and other small insects and birds

Birds do it. Bees do it. And in a laboratory in northern California, scientists using bumblebees recently figured out the best way to measure it--vertical lift!

The post Laboratory tests reveal precise way to measure vertical lift in bumblebees and other small insects and birds appeared first on Smithsonian Insider.




sec

From chewing tough insects to soft fruit, bat teeth are highly specialized


They found that the molars of fruit-eating species had sharp outer edges that likely allow them to pierce tough fruit skin and pulp... By contrast, the molars of insect-eating species were less complex, possibly because of their smoother shearing surfaces.

The post From chewing tough insects to soft fruit, bat teeth are highly specialized appeared first on Smithsonian Insider.




sec

Lofty experiments with gliding ants reveals secrets of their unusual flight

One of the most challenging aspects of this research is simply studying these insects as they are falling, says Yanoviak, a tropical arthropod ecologist at the University of Arkansas, Little Rock. Small body size, rapid descent, and the long distances that they can fall, make accurate data taking a challenge.

The post Lofty experiments with gliding ants reveals secrets of their unusual flight appeared first on Smithsonian Insider.




sec

First ever record of insect pollination captured in 100 million-year-old amber

Scientists have discovered several specimens of tiny insects covered with pollen grains in two pieces of amber, revealing the first record of pollen transport and social behavior in this group of animals.

The post First ever record of insect pollination captured in 100 million-year-old amber appeared first on Smithsonian Insider.




sec

Female “spidernaut” settles into new home at Smithsonian’s Insect Zoo

The new Sant Director of the National Museum of Natural History, Kirk Johnson, had only been on the job for 26 days when he got […]

The post Female “spidernaut” settles into new home at Smithsonian’s Insect Zoo appeared first on Smithsonian Insider.




sec

Smithsonian secretary on the future of museums, libraries and archives

To download the free e-book Best of Both Worlds: Museums, Libraries, and Archives in a Digital Age, by G. Wayne Clough, Secretary of the Smithsonian, […]

The post Smithsonian secretary on the future of museums, libraries and archives appeared first on Smithsonian Insider.




sec

Non-insect invertebrates are focus of new global genome-sequencing alliance

For scientists who study non-insect invertebrates, the sheer diversity of these odd and fascinating creatures is both intoxicating and daunting. Occupying niches in habitats the […]

The post Non-insect invertebrates are focus of new global genome-sequencing alliance appeared first on Smithsonian Insider.






sec

The secret formula to feeding 900 babies: Scientists uncover milk composition of naked mole-rat queens

Parents normally feel the need to provide well for their kids. For humans, that number of offspring is usually in the single digits, but a […]

The post The secret formula to feeding 900 babies: Scientists uncover milk composition of naked mole-rat queens appeared first on Smithsonian Insider.





sec

Bats Use Second Sense to Hunt Prey in Noisy Environments

Like many predators, the fringe-lipped bat primarily uses its hearing to find its prey, but with human-generated noise on the rise, scientists are examining how […]

The post Bats Use Second Sense to Hunt Prey in Noisy Environments appeared first on Smithsonian Insider.





sec

New study indicates mysterious fast radio bursts occur in universe every second

When fast radio bursts, or FRBs, were first detected in 2001, astronomers had never seen anything like them before. Since then, astronomers have found a […]

The post New study indicates mysterious fast radio bursts occur in universe every second appeared first on Smithsonian Insider.



  • Research News
  • Science & Nature
  • Space
  • Center for Astrophysics | Harvard & Smithsonian
  • Smithsonian Astrophysical Observatory

sec

Global security groups





sec

Secret Adventures: “Claws and Effect”

This Secret Smithsonian Adventures series follows four middle schoolers as they foil events by two dastardly doers who try to dangerously change the true course […]

The post Secret Adventures: “Claws and Effect” appeared first on Smithsonian Insider.




sec

OPTN recruitment to a Golgi-proximal compartment regulates immune signalling and cytokine secretion [RESEARCH ARTICLE]

Thomas O'Loughlin, Antonina J. Kruppa, Andre L. R. Ribeiro, James R. Edgar, Abdulaziz Ghannam, Andrew M. Smith, and Folma Buss

Optineurin (OPTN) is a multifunctional protein involved in autophagy, secretion as well as NF-B and IRF3 signalling and OPTN mutations are associated with several human diseases. Here we show that, in response to viral RNA, OPTN translocates to foci in the perinuclear region, where it negatively regulates NF-B and IRF3 signalling pathways and downstream pro-inflammatory cytokine secretion. These OPTN foci consist of a tight cluster of small membrane vesicles, which are positive for ATG9A. Disease mutations linked to POAG cause aberrant foci formation in the absence of stimuli, which correlates with the ability of OPTN to inhibit signalling. Using proximity labelling proteomics, we identify the LUBAC complex, CYLD and TBK1 as part of the OPTN interactome and show that these proteins are recruited to this OPTN-positive perinuclear compartment. Our work uncovers a crucial role for OPTN in dampening NF-B and IRF3 signalling through the sequestration of LUBAC and other positive regulators in this viral RNA-induced compartment leading to altered pro-inflammatory cytokine secretion.